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BOOK of ABSTRACTS

MARC XI

Eleventh International Conference on Methods and Applications of Radioanalytical Chemistry

April 8 -13, 2018

Final version: March 1, 2018

www.marcconference.org

MARCXIFinalBookofAbstracts

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The organizers of the Eleventh International Conference on Methods andApplications of Radioanalytical Chemistry (MARC XI) conference are pleased toprovidethefollowingsummaryofabstractsforreferencebyattendeesoftheMARCXI conference. These materials are a supplement to the actual Program, whichprovidescompletedetailsoftheconferenceandsequenceofpresentations.However,itwillnotincludeacopyofalltheabstracts,asitwouldbeaverylargepublication.MARCXIisexpectedtobeoneofthelargestMARCconferencewithover450abstractssubmitted.Thefollowingnearly200pagesprovidetheabstractssubmittedforpresentationatthe MARC XI conference as of March 1, 2018. The list will only be providedelectronicallyandonlyasmallnumberofhardcopyabstractsummarybookswillbeavailable forreferenceat theconferenceat thedesk. Individualcopieswillnotbeprovided.If you have any questions, please contact the program chair, Sam Glover([email protected]). Please visit the MARC website for additional details atwww.marcconference.org.


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Log 103. DR. ROLF ZEISLER: A CAREER REFLECTED IN 30 YEARS OF MARC. Heller-Zeisler, S.F. (1). (1) National Institute of Standards and Technology (retired). Drawing from the work authored and co-authored by Dr. Rolf Zeisler throughout the progression of the MARC conferences, this presentation highlights a few of his many career achievements. Spanning his extensive history with the conferences, the presentation touches on some of his notable research areas, including low-level trace element determinations, elemental speciation, radiochemical determinations, and the use of state-of-the-art instrumentation to push the boundaries of activation analysis. Never satisfied with existing limitations, he constantly pushed to improve the accuracy in analytical determinations of trace elements. To do so, he solicited a diverse group of collaborators possessing a wide range of analytical expertise. This approach reflected his drive to identify the particular analytical technique or set of techniques appropriate to achieve the desired goals of lowering detection limits and/or improve accuracy for the samples being investigated. In the use of instrumental methods, this has ranged from employing instrumental neutron activation analysis (INAA) using Compton Suppression and investigations on the accuracy of high count rate gamma spectrometry. In prompt gamma activation analysis (PGAA), he continually pushed to use coincidence and anti-coincidence techniques, starting with measurements in pulsed cold neutron beams, and moved to time-resolved gamma-ray spectrometry. In addition to pushing boundaries on the instrumental side, he also remained a steadfast supporter of radiochemical techniques where appropriate, to achieve more precise results and lower detection limits. This has been both in combination with INAA, as in the case of the human liver sample analyses, but has also included more directed measurements by radiochemical separations, e.g. for Si and for Al, V, and Ni in reference materials and challenging biological matrices. His work has also included the development and characterization of new reference materials. Some of this work is highlighted here, including his work on the air particulate matter on filters, which led to Standard Reference Material (SRM) Air Particulate on Filter Media, SRM Fine Air Particulate Matter, and RM Air Particulate Matter on Filter Media. These are the first RMs of this kind worldwide. His continued interest in trace element speciation supported his involvement in the collaboration to develop the hair intercomparison materials for mercury speciation. In addition to these, he strove to achieve the most accurate and precise measurements for existing reference materials. To evaluate long-term stability, he initiated oxygen measurements in a coal SRM via 14 MeV NAA in order to determine any chemical change through oxidation over time. He also collaborated with his NIST colleagues toward the demonstration of viability of INAA in chemical metrology, surveying the uncertainty components that affect the INAA measurement process. The process was tested with the INAA determination of Cr in SRM 1152A stainless steel. Throughout his career, he served as a mentor to young scientists worldwide. Following this interest, in addition to his research presentations at the MARC meetings, he worked on the continuing discussions on how to further radiochemical education in the U.S. and abroad. He was co-organizer on three successive sessions on Nuclear Science Manpower and Education panels (MARC-VI, VII, and VIII). The first session resulted in a resolution on Manpower Requirements and Education in Nuclear Science, signed by attendees at the meeting. The follow-up sessions described the progress and specific examples of programs, as well as continuing needs. Dr. Zeisler made an indelible mark in furthering excellence in the field of analytical science and in the lives of those individuals who knew him. Log 105. ENVIRONMENTAL BEHAVIOR OF PLUTONIUM: SCIENTIFIC CHALLENGES FOR CLEAN-UP AND SAFE LONG-TERM STORAGE. Kersting, A.B (1). (1) Los Alamos National Laboratory. Today the global inventory of plutonium (Pu) is approximately 2,500 t resulting from both weapons related activities and the nuclear fuel industry, with yearly increases estimated between 70-90 t. Due to its long half-life (239Pu 2.41 x 104 years) and high toxicity, safely isolating and storing this plutonium as well as the rest of our high-level nuclear waste remains a pressing scientific challenge. Although we have made significant progress on better understanding the mechanistic behavior of Pu, knowledge gaps still remain, hampering our ability to model its transport behavior and achieve confidence in predicting its long-term behavior. These gaps hamper progress on convincing a skeptical public that we can clean up and safely isolate this waste for the thousands of years necessary to protect the biosphere. In this presentation, I will give an overview of our current state of knowledge on the environmental behavior of Pu, discuss the significant progress we have made, and highlight some of the most pressing knowledge gaps that still need addressing.


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Log 106. NUCLEAR EMERGENCIES: A CHALLENGE FOR SCIENCE AND SOCIETY. Steinhauser, G. (1). (1) Leibniz University Hannover. Nuclear emergencies include nuclear accidents as well as nuclear terrorism, the use of nuclear or radiological weapons, illicit trafficking of nuclear materials, etc. Such emergencies pose an imminent threat to the fabric of society. They may be relevant by direct, indirect, and perceived harm to human health and the environment. The nuclear community has established profound knowledge and strategies to help prevent nuclear emergencies and to mitigate their effects. However, while focusing on becquerels, sieverts and grays, the community quite often tends to forget the social aspects of a nuclear emergency. Some initiatives have been launched recently to close this gap for a good reason: the nuclear community may effectively benefit from a more holistic view on the subject. Log 107. PRODUCTION AND APPLICATIONS OF STABLE AND RADIOISOTOPES: A GLOBAL PERSPECTIVE OF SUPPLY AND DEMAND. Runde, W.H (1). (1) Los Alamos National Laboratory. Stable and radioisopes are vital to the research and applications in a number of disciplines such as (bio, geo)chemistry, medicine, agriculture, energy or national defense. They can occur naturally or can be produced artificially in highly specialized facilities using separators, accelerators or nuclear reactors. This presentation provides an overview of main production technologies and examines the current and future supply situation for the most commonly used radioisotopes for various applications. Log 108. CHARACTERIZATION OF SEIZED NUCLEAR MATERIALS BY A LABORATORY SPECIALIZED IN TRACE ANALYSES OF RADIONUCLIDES FOR SAFEGUARDS AND ENVIRONMENTAL MONITORING: EXPERIENCE AND PERSPECTIVES. Pointurier, F. (1); Fauré, A.L. (1); Hubert, A. (1); Humbert, A.C. (1); Hubert, A. (1); Haedrich, H. (1); Marie, O. (1); Rivière, G. (1); Roche, E. (1); Greiner, V. (1); Douysset, G. (1); Bernard-Michel, B. (1). (1) CEA, France. Analytical expertise unit of the French Atomic Energy Agency (CEA) in Arpajon is mainly involved in analysis of environmental samples for safeguards and environmental monitoring of some French nuclear sites. In this respects, the unit is since 2001 a member of the IAEA’s Network of Analytical Laboratories for nuclear safeguards, both for bulk and particle analysis of environmental samples. So the unit has strong experience in radiochemical purifications of minute amounts of uranium and plutonium, and precise measurement of U and Pu isotopic compositions at trace level by mass spectrometry (ICPMS, SIMS or TIMS). These isotopic capabilities are completed by implementation of scanning electron microscopy, micro-Raman spectrometry, low-level gamma spectrometry, detection of specific elemental impurities and uranium age determination. Moreover, since a few years, the unit is also regularly involved in the characterization of nuclear material samples, mainly in the framework of international exercises. Therefore, developments of analytical methods for safeguards are conducted with a view to be applicable both to the low amounts of nuclear materials encountered in typical environmental samples and to macroscopic nuclear materials. The goals of this presentation are to show how a laboratory mainly specialized in the analysis of radionuclides (mainly uranium and plutonium) at trace level can efficiently contribute to the full characterization of macroscopic nuclear materials, to present capabilities, results and experience acquired through CMX exercises, and also to discuss how these capabilities can be improved, both regarding timelines and diversity of the provided information.


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Log 110. ROLF ZEISLER AND OPPORTUNITIES IN NUCLEAR METHODS. Lindstrom, R.M. (1). (1) National Institute of Standards and Technology. In 1986, Rolf Zeisler seized an opportunity at the newly opened cold-neutron guide hall at KFA Jülich, and arranged for NIST to gain the experience to design our own system. With Matthias Rossbach, we made 90 hours of measurements in three intense weeks, and then two weeks later presented our work at MTAA-7. The title was Rolf’s: “Activation Analysis Opportunities Using Cold Neutron Beams”. This paper laid out all the issues to be developed in the next decades of progress in PGAA. Rolf continued to be innovative in applying nuclear methods to improve elemental analysis. His leadership in environmental specimen banking and air particulate collection and analysis has led to numerous Standard Reference Materials, and his enthusiasm for improved instrumentation has substantially improved the accuracy and applicability of nuclear analytical methods at NIST and elsewhere. Rolf’s activities in the analytical community were extensive, being deeply involved in the organization of MARC, MTAA, NAMLS, ANS, and other series of meetings to bring his expertise and passion to us all. Log 111. THE USE OF CROSS-LINKED ANTIMICROBIAL NANOCOMPOSITE FILMS AND GAMMA IRRADIATION TO ASSURE THE SAFETY OF FRESH MEATS. Lacroix, M. (1); Khan, A. (1); Gallah, H. (1); Riedl, B. (2); Bouchard, J. (3); Safrany, A. (4). (1) INRS-Institut Armand-Frappier/Canadian Irradiation Centre. (2) Département des sciences du bois et de la forêt, Université Laval. (3) FP Innovation. (4) International Atomic Energy Agency. A 125 .g/mL of nisin and 30 mM of disodium ethylenediaminetetraacetate (EDTA) were immobilized on the surface of the nanocrystal (CNC)/chitosan nanocomposite films by using genipin as a cross-linking agent. The effect of low-dose gamma irradiation on the antimicrobial activity of the films was tested in vitro against Escherichia coli and Listeria monocytogenes. The genipin cross-linked films prepared by irradiating at 1.5 kGy demonstrated the highest antimicrobial activity against both the bacteria at the end of 35 days of storage at 37 °C showing an inhibition zone of 27.1 mm for E. coli and 27.7 mm for L. monocytogenes as compared to 23.4 mm and 23.8 mm for the same respective bacteria at day 1. The films restricted the growth of psychrotrophs, mesophiles, and Lactobacillus spp. (LAB) in fresh pork loin meats and increased the microbiological shelf-life of meat sample by more than 5 weeks. The films also reduced the count of E. coli and L. monocytogenes in meat samples by 4.4 and 5.7 log CFU/g, respectively, after 35 days of storage. Log 112. EFFECT OF GAMMA-IRRADIATION IN COMBINATION WITH MARINATING TO ENSURE THE SAFETY AND TO PROTECT THE NUTRITIONAL VALUE OF READY-TO-COOK MEAT FOR IMMUNOCOMPROMISED PATIENTS. Lacroix, M. (1); Fadhel, Y.B. (1); Leroy, V. (1,2); Dussault, D. (3); St-Yves, F. (4); Lauzon, M. (4); Salmieri, S. (1); Jamshidian, M. (1); Vu D.K. (1); Kermasha, S. (5). (1) INRS-Institut Armand-Frappier. (2) University of Tours, France. (3) BSA Food Ingredients Inc., Canada. (4) Montmorency College, Canada. (5) Mc Gill University, Canada. The aim of this study was to evaluate the effect of combining marinating and .-irradiation at doses of 1, 1.5, and 3 kGy on Escherichia coli O157:H7, Salmonella Typhimurium, and Clostridium sporogenes in raw meat packed under vacuum and stored at 4 °C and to estimate its safety and shelf-life. Further, the effect of combined treatments on sensorial, nutritional values (lipid oxidation, concentration of thiamin and riboflavin), and color were evaluated. The study demonstrated that the use of marinade in combination with a low dose of .-irradiation (1.5 kGy) could act in synergy to reduce to undetectable levels of pathogenic bacteria and increase the shelf-life of ready-to-cook meat loin without affecting its sensorial and nutritional quality.


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Log 113. RADON IN DRINKING WATER IN MEXICO CITY. Espinosa, G. (1); Golzarri, J.l. (1). (1) Physics Instituto, Universidad Nacional Autónoma de México (UNAM). Exposure to radon occurs when people drink water or breathe gas radon emitted from drinking water containing radon. International Epidemiological authorities recognized that exposure to radon from drinking water is a potential health hazard, as has been considered worldwide. In Mexico City, with more than 20 million inhabitants, the population is exposed to the emanation of radon of the drinking water from the federal water supply system. Presented in this paper are the results of the radon concentration measurements in drinking water, from 45 wells of the federal water supply system, that represents the 33% of the drinking water consumed by the Mexico City population. The United States Environmental Protection Agency (USEPA) has proposed a limit of 11.1 Bq/1 for the radon concentration level in drinking water in order to minimize the radiological risk to the population. In this work, the measurements of radon (222Rn) concentration in drinking water in Mexico City revealed concentration ranging from the lower limit of the instrumentation, 0.11 Bq/l, up to 2.4 Bq/l. The radon concentration measurements were made using an AlphaGUARD radon measurement system together with an AquaKIT portable degassing system, the latter with an air flow of 0.3 l/min, using Genitron Instruments Data EXPERT software, following a very well established protocol. These radon concentration levels are very important from the public health point of view, and it will be recommendable to measure the radon concentration in drinking water periodically in order to prevent the occurrence of epidemiological problems in the population. Log 114. LONG-LIVED CONTAMINANTS IN CYCLOTRON-PRODUCED RADIOPHARMACEUTICALS - MEASUREMENT AND DOSIMETRY. Metzger, R.L. (1); Lasche, G.P. (2); Eckerman, K.F. (3); Leggett, R.E. (4). (1) RSE, Inc. (2) Snakedance Scientific. (3) Easterly Scientific. (4) ORNL. Oxygenated target waters of cyclotron targets contain long-lived contaminants due to (p,n) reactions in the HAVAR target window that are spalled into the target water. These contaminants are largely removed during the synthesis of the final imaging agent. Currently, the USP requires that the final drug product be 99.5% pure, so the total activity of the long-lived contaminants can be no more than 0.5% of the final radiopharmaceutical product. A method has been developed to identify and quantify the primary contaminants using high resolution gamma spectroscopy and VRF, a new spectrum analysis tool. Uptake, retention, and excretion functions for each of the contaminating isotopes in a soluble, injected chemical form have also been calculated using International Commission on Radiological Protection (ICRP) Publication 123 models and are presented in the Appendix. In addition, specific organ and effective dose coefficients were also calculated using ICRP Publication 103 tissue weighting factors and are also presented in the Appendix. Typical imaging agents have contaminant loads far below the USP limit and contribute negligible doses to the patients receiving the drugs.


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Log 115. LONG-LIVED CONTAMINANTS IN CYCLOTRON-PRODUCED RADIOPHARMACEUTICALS - HOMELAND SECURITY DETECTORS. Metzger, R.L. (1); Van Riper, K.A. (2); Eckerman, K.F. (3); Leggett, R.E. (3). (1) RSE, Inc. (2) White Rock Science. (3) ORNL. In the USA during 2015 over 1,718,500 clinical PET scans were performed in 2,380 centers. Patients undergoing these studies will alarm homeland security monitors at borders, ports, and some airports for up to two days due to the positron-annihilation photons (0.511 MeV) from the imaging isotope F-18 (110 min half-life). In some radiopharmaceuticals, long-lived contaminants generated from the activation and spallation of elements in the HAVAR window of the cyclotron target may also be present in the patient dose. In this work, we have modeled a typical homeland security portal monitor in MCNP, and determined its sensitivity to each of the possible contaminating isotopes found in PET radiopharmaceuticals when distributed in patient phantoms. These data were combined with the time-dependent uptake/retention functions for the contaminating isotopes, developed in other work, to identify the isotopes that can cause alarms for substantial periods of time after the short-lived imaging agent has decayed away. Results indicate that Cr-51, Mn-54, Co-56, and Co-58 are avidly retained in the body, have relatively long biological half-times, and have energetic photon emissions that couple well with the large area scintillators commonly found in Homeland Security detectors. Cyclotron-produced radiopharmaceuticals that contain any of these isotopes as contaminants can cause patients to alarm Homeland Security detectors for several months after the F-18 has decayed away, even with contaminant loads that are <10% of the USP allowed values. Log 117. EXPLOSIVE DISPERSAL OF ACTIVATED KBr: A REALISTIC AND CHALLENGING TRAINING ENVIRONMENT FOR THE NATION'S FIRST RESPONDERS. Mann, N. (1); Giles, J. (1); Carney, K. (1); Turnage, J. (1); Hines, C. (2); Restis, K. (2). (1) Idaho National Laboratory. (2) Washington State University. To date, the malicious use of a Radiological Dispersal Device (RDD) in a public setting is an untested threat to the nation's first responders. Although untested, proper training and preparation are required in the event that an actual radiological terror incident occurs. The Idaho National Laboratory (INL) has a long lived and successful training program to address the potential need for interaction with both nuclear material and highly radioactive sources, including RDDs. Several emergency response communities have expressed the need for more realistic conditions to support training, including testing of detectors, sampling technologies, and characterization of radioactive dispersals. To meet this need, the INL and Washington State University have created a unique and challenging training environment by dispersing irradiated potassium bromide (KBr) by way of high explosives. The INL is the only location able to provide a realistic training environment of this type that immerses students in RDD type scenarios with authentic measurement, equipment, and radiological source materials.


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Log 118. ACTIVITY CONCENTRATION OF NATURALLY OCCURRING RADIONUCLIDES AND RADON EXHALATION RISKS ON DWELLERS FROM COMMERCIAL BUILDING MATERIALS IN NIGERIA. Omeje, M. (1); Adewoyin, O.O. (1); Joel, E.S. (1); Usikalu, M.R. (1); Cyril, E.E. (2); Odukoya, A.M. (3); Oyawoye, F.O. (3); Hassina, M. (4); Mohamad, A.S. (5); Zaidi, E. (6). (1) Department of Physics, Covenant University, Nigeria. (2) Department of Chemistry, Covenant University, Nigeria. (3) Department of Geosciences, University of Lagos, Nigeria. (4) Department of Geology, University of Johannesburg, South Africa. (5) Department of Physics, Universiti Teknologi Malaysia, Malaysia. (6) Universiti Tun Hussein Onn Malaysia, Malaysia. A study on the building materials of different brands of tiles, marbles, cements, and sand were used to study the radioactivity and its radiological exposure to inhabitants in Nigeria using High Purity Germanium Gamma (HPGe) detector. The activity concentrations obtained were used to estimate the radon exhalation rate and other radiological risks of radium equivalent activity (Raeq), internal hazard index (Hin), external hazard index (Hex), absorbed dose rate (DR), annual effective dose rate (AEDR), gamma index, and alpha index. The mean activity concentrations in all the samples ranged from 51.5 ± 9.3, 72.46 ± 17.65, and 217.05 ± 44.31 Bqkg-1 for 226Ra, 232Th, and 40K respectively. The Raeq activity obtained from all the analyzed samples were noted to be < 370 Bqkg-1 as the recommended dose limiting safe value for bulk media as presumed. The value of 122.52 nGyh-1 noted in Virony tile sample for the indoor absorbed dose rate is higher than the weighted population world average value of 80 nGyh-1 by a factor of 1.53. The highest annual effective dose obtained from this study falls below the maximum dose limit of 1 recommended by international standard. The correlation coefficient between the DR and Raeq activity indicated positive, revealing that increase in Raeq enhances the dose exposure to the dwellers. It was observed that the radon concentration varies from 0.1275 to 0.4075 which is < 1, indicates that the radon exhalation from all the analyzed samples would cause indoor concentration lower than 200 Bqkg-1 safe level for dwellers.

Log 119. RADIOLOGICAL HAZARD RISK OF 226Ra, 232Th AND 40K FOUND IN SELECTED BUILDING MATERIALS AND IN NIGERIA. Omeje, M. (1); Adewoyin, O.O. (1); Joel, E.S. (1); Usikalu, M.R. (1); Cyril, E.E. (2); Odukoya, A.M. (3); Oyawoye, F.O. (3); Hassina, M. (4); Mohamad, A.S. (5); Zaidi, E. (6). (1) Department of Physics, Covenant University, Nigeria. (2) Department of Chemistry, Covenant University, Nigeria. (3) Department of Geosciences, University of Lagos, Nigeria. (4) Department of Geology, University of Johannesburg, South Africa. (5) Department of Physics, Universiti Teknologi Malaysia, Malaysia. (6) Universiti Tun Hussein Onn Malaysia, Malaysia. The activity concentration of 226Ra, 232Th, and 40K measured in commonly used in Nigeria from commercial supplier using High Purity Germanium Gamma (HPGe) detector. The mean activity concentrations in the samples ranged from 27 +/- 9.5 to 76.5 +/- 2.5 Bqkg-1 for 226Ra, 41 +/- 4 to 96 +/- 8.3 Bqkg-1 for 232Th and 140 +/- 7.9 to 940 +/- 19.2 Bqkg-1 for 40K respectively. The highest radium equivalent (Raeq) of 264.5 Bqkg-1 was found to be < 370 Bqkg-1 as the recommended dose limiting safe value for bulk media as presumed, the highest value of internal hazard index (Hin) and external hazard index (Hex) of 0.894 and 0.744 respectively were also < 1. The absorbed dose rate (DR) with a value of 122.52 nGyh-1 noted in Virony tile sample is higher than the weighted population world average value of 80 nGyh-1 by a factor of 1.53. The highest annual effective dose rate (AEDR) of 0.601 mSvy-1 reported in PNT ceramics but was found to be less < 1 mSvy-1. The investigated materials have the values of Hin, Hex and AEDR greater than 0.5 but less than1, showing that the dose impact exceeds the exemption dose level of 0.3 mSvy-1 for AEDR but complies with the upper limit of dose principle of 1 mSvy-1.


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Log 120. ASSESSMENT OF NATURAL RADIOACTIVITY IN VARIOUS COMMERCIAL TILES USED FOR BUILDING PURPOSES IN NIGERIA. E.S Joel (1); Omeje, M. (1); Adewoyin, O.O. (1); Folajimi (2); Ehi-Eromosele, C. (3). (1) Department of Physics, Covenant University Ota, Nigeria. (2) Department of Geosciences, University of Lagos, Nigeria. (3) Department of Chemistry, Covenant University Ota, Nigeria. In this study, we evaluated the activity concentration of natural radionuclides (226Ra, 232Th and 40K) for fifteen (15) different brands of tile samples used for building purposes in Nigeria. The tile samples were analyzed using High purity Germanium gamma detector. The mean activity concentrations of 226Ra, 232Th, and 40K were observed to be 61.1, 70.2 and 514.7 Bq/kg respectively. Various hazard indices such as absorbed dose rate, external and internal hazard index, and annual effective dose rate were calculated. The obtained results showed that the mean radium equivalent activity (Raeq), the absorbed dose rate (D), external and internal hazard index, and the annual effective dose (AEDR) equivalent were: 204.42 Bq/kg, 177.61 nGyh-1, 0.55, 0.77 and 0.96 mSvyr-1, respectively. The average value of radium equivalent obtained in this study is less than that of the recommended value of 370 Bq/kg but the average values of the other radiological hazards for some samples are found to be slightly above international recommended values except Hex, Hin, and AEDE, which are within the international reference value of unity. The measured concentrations of these radioactive materials were correlated with other previous results obtained from similar tile materials used in other countries and found to be in good agreement, however, recommends for decoration in Nigeria. Log 121. DRILLERS' EXPOSURE TO NATURAL RADIOACTIVITY AND ITS RADIOLOGICAL RISKS IN LOW LATITUDE REGION USING NEUTRON ACTIVATION ANALYSIS. Omeje, M. (1); Adagunodo, T.A. (1); Akinwumi, S.A. (1); Adewoyini, O.O. (1); Joel, E.S. (1); Husin; W. (2); Mohd, S.H. (3). (1) Department of Physics, Covenant University, Nigeria. (2) Department of Physics, Universiti Teknologi, Malaysia. (3) Malaysia Nuclear Agency. The radioactivity of 226Ra as well as 232Th decay chains for the lithological rock samples could be at equilibrium considering the age as well as the isotopic mass proportion, which is assumed to be equal to its natural isotopic. Neutron Activation Analysis (NAA) is adopted for this study with the aim of minimizing sample size as well as less counting rate to estimate the radioactivity concentration in rock samples. Two boreholes were drilled in Abuja in order to randomly collect the rock samples from three different layers of each site. All the samples were duplicated for each radionuclide examination, resulting in twelve samples in all. The results showed that the activity concentrations of 226Ra, 232Th and 40K in the two sites are in the order 232Th > 226Ra > 40K. 226Ra and 232Th possess activity concentration greater than the world's average while 40K activity is lesser than the world's average. The radiological risks estimated showed that more than half of the parameters used nearly exhibit greater values than the global average values. It is concluded that Abuja is underlain by rocks of low potassic value. If the drillers do not take caution about the geologic formation of the subsurface and apply necessary precautions before drilling commences, over-exposure to these -radiation may pose unquantifiable health risks to them. Log 124. UNCONVENTIONAL METAL-PHOSPHONATE FRAMEWORKS AS RADIOANALYTICAL SEPARATION CANDIDATES: A HYBRID PERSPECTIVE. Kai, Lv. (1); Wang, X. L. (2). (1) Institue of Nuclear Physics and Chemistry, China Academy of Engineering Physics. (2) China Academy of Engineering Physics. A category of hierarchically porous metal (IV, V) alkylphosphonate frameworks have been fabiracated and exploited as radioanalytical separation candidates, harvesting lanthanides or light actinides from a multitude of radionuclide surrogates in solid phase extraction mode. It is demonstrated that hierarchically porous morphology and unsaturated phosphonate ligands collectively dictate the uptake discrepancy in acidic media, enabling the establishment of selective, facile radioanalytical separation schemes for actinides or fission products. Moreover, miscellaneous organic inorganic brid materials will be briefly reviewed in the "cradle to grave" perspective together with the emphasis on this class of unconventional metal-phosphonate framework (UMPF), thus shedding some light on the expansion of efficient practical radioanalytical separation protocols.


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Log 125. APPLICATION OF SILICON DRIFT DETECTOR TO NUCLEAR FORENSICS. Thornock, K. (1); Shield, K. (2); Rundberg, R. (3). (1) University of Nevada, Las Vegas. (2) University of California, Berkeley. (3) Los Alamos National Laboratory. Silicon Drift Detectors are an emerging category of semiconductor detectors capable of measuring x-ray photons. They are uniquely capable of measuring x-rays in the fingerprint region below 18 keV. To determine the resolution and capabilities of a silicon drift detector, we first calibrated it using a variety of radioactive elements. In the process of this calibration, we observed peaks from the decay of Ho-166m that had previously only been theorized. In addition, we found the silicon drift detector capable of distinguishing between U-235, U-238, and Pu-239, providing potential applications in nuclear forensics. Further analysis of data from the silicon drift detector may provide methods to determine isotopic ratios of these elements and additional special nuclear materials. Log 126. RAPID METHOD FOR LOW LEVEL Sr-90 DETERMINATION IN SEAWATER. Visetpotjanakit, S. (1); Nakkaew, N. (1). (1) Office of Atoms for Peace. Determination of low level Sr-90 in seawater has been widely developed for purpose of environmental monitoring and radiological research since Sr-90 is one of the most hazardous radionuclides released from atmospheric nuclear weapon testing, nuclear waste discharge, and nuclear accident. Liquid extraction technique using bis-2-etylhexyl-phosphoric acid to separate and purify Y-90 and Cherenkov counting using liquid scintillation counter to determine Y-90 in secular equilibrium to Sr-90 were developed to monitor Sr-90 in our Asian Pacific ocean. The analytical performance was validated for the accuracy, precision, and trueness criteria. Sr-90 determination in seawater using various low concentrations in a range of 0.01 - 1 Bq/L of 30 liter spiked seawater samples and 0.5 liter IAEA-RML-2015-01 proficiency test samples were performed for statistical evaluation. The results had relative bias in range from 3.42% to 12.28%, below accepted relative bias of 25% and passed the criteria which could confirm our analytical performance of low level Sr-90 determination in seawater. Moreover the approach is economical, non-laborious, and fast to analyse Sr-90 in seawater. Log 127. COORDINATION STRUCTURE OF URANIUM COMPLEXES IN DISORDERED SYSTEMS USING X-RAY ABSORPTION FINE STRUCTURE SPECTROSCOPY. Zhang, L. (1); Wang, J.Q. (1,2). (1) Department of Molten Salt Chemistry and Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences. (2) Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China. Separation of uranium from spent nuclear fuel is a key part of advanced nuclear fuel cycle systems, in which high-temperature molten salt is an important reaction and electrolytic media in fuel reprocessing. In addition, extraction of uranium from seawater is expected as a rich supply for long-term nuclear power production, in which development of robust adsorbents with high selectivity is critical to realize the feasibility of uranium extraction. Understanding the coordination structure of uranium in high temperature molten salt and the adsorption mechanism between the functionalized ligand and uranium in aqueous solution helps to improve the separation and extraction efficiency, and thus guide the electrolysis and distillation technologies as well as the design of adsorbent functionalized groups. The fundamental challenges above are closely related with the coordination chemistry of uranium in disordered systems: molten salt and aqueous solution. However, conventional experimental techniques are disabled, whereas synchrotron radiation (SR) techniques are promising for extracting the local coordination environment around uranium. Among SR-based techniques, X-ray absorption fine structure spectroscopy (XAFS) has been widely confirmed as an element-selective and atomic level probe, which can unveil the chemical environment and bonding information in the actinide chemistry. In present work, we will discuss our research progress on the coordination environment of uranium complex in molten salts and aqueous solution using XAFS measurement as well as theoretical simulation.


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Log 128. THE AUTOREDUCTION KINETICS OF 243Am. Grimes, T.S. (1); Horne, G. P. (1); Mezyk, S.P. (2); Dares, C.J. (3). (1) Idaho National Laboratory. (2) California State Long Beach. (3) Florida International University. Although the first reports of a hexavalent oxidation state for americium are from the 1950s, this valence state is difficult to prepare and maintain in acidic solutions. Therefore, past reports on its basic chemistry have sometimes been inconsistent. Given our group's interest in the chemistry of Am(VI) for separations purposes, we have reinvestigated its autoreduction kinetics. The concentration changes of Am(III), Am(V) and Am(VI) were determined by UV-vis spectroscopy. The Am(III) molar extinction coefficients are known; however, the unknown values for Am(V) and Am(VI) across a range of nitric acid concentrations were determined by sensitivity analysis in which mass balance with the known total americium concentration was obtained. Reduction rates exhibited zero-order kinetics with respect to the concentration of hexavalent americium, and pseudo-first-order kinetics with respect to the concentration of total americium. The rate constants varied with nitric acid concentration. This indicates that reduction is due to reaction of hexavalent americium with the radiolysis products of total americium decay, and that those reducing species concentrations vary with the concentration of irradiated nitric acid, since the acid itself is redox active under radiolysis. Multi-scale radiation chemical modeling using a reaction set with both known and optimized rate coefficients was employed to achieve excellent agreement with the experimental results, and indicates radiolytically-produced nitrous acid from nitric acid radiolysis, and hydrogen peroxide from water radiolysis are the important reducing agents. Log 129. ACTINIDE MATERIAL AND CHEMISTRY RESEARCH IN SHANGHAI SYNCHROTRON RADIATION FACILITY. Bao,H. (1), Lin, J. (1), Zhang, L. (1), Wang, J.Q. (1,2). (1) Department of Molten Salt Chemistry and Engineering, Shanghai Institute of Applied Physics, Chinese Academy of Sciences. (2) Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China. The nuclear fuel cycle consists of front end that prepares uranium or thorium fuel for use in nuclear reactors and back end to dispose of spent nuclear fuel. Chemical processing of spent fuel material to recover the remaining product, such as uranium, thorium, and other elements from fission products to reprocess nuclear fuel is still a big challenge. Understanding the structure and chemical state in complex systems, change of valence state and concentrations during the process, and chemical behaviors at the interface of two-phases are possible with different power advance synchrotron radiation techniques. Recently, we developed some techniques and performed some basic research of uranium, thorium chemistry in SSRF. As such, we synthesize series of thorium mixed selenite selenate compounds, determined the coordination structure. We also built in situ XAS platform to investigate the structure change of UO2-ThO2 from molecular level at different conditions by HERFD-XAS. Furthermore, the first actinide research synchrotron beamline in China is in-building and will serve for the community of actinide material and chemistry.


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Log 130. MICRO SCALE MONITORING OF COMPLEXATION AND PHASE TRANSFER KINETICS OF TRIBUTYL PHOSPHATE AND ITS DEGRADATION PRODUCTS DURING SOLVENT EXTRACTION. Howett, S. (1); Bottenus, D. (1); Lines, A. (1); Louie, C. (1,2); Bryan, S. (1); Delegard, C. (3); Clark, S. (1,2); Pitts, W.C. (1); Casella, A. (1). (1) Pacific Northwest National Laboratory. (2) Washington State University. (3) TradeWind Services LLC. The efficiency and effectivity of solvent extraction is dictated by butyl phosphate (BP) extractants and actinide transport across the liquid:liquid interface. Tributyl phosphate, one such extractant in liquid:liquid reprocessing, undergoes radiolytic degradation and hydrolysis, resulting in dibutyl phosphate (DBP) and monobutyl phosphate (MBP) yields. Both species can result in the production of interfacial solids at the organic:aqueous phase boundary, reducing the extraction efficiency and effectivity. To understand the formation of these unwanted solids, the kinetics of complexation and the interfacial mass transfer of BP species at and across the interface must be understood. The extraction apparatus used is a microfluidic device. Alternating organic and aqueous phase droplets flow down the microfluidic channel, providing a controlled interface between droplets. Raman spectroscopy is used as an on-line monitor for the phase transfer of species between the alternative phases. The monitoring allows for direct measurement of complexes and species between the alternating phases. Raman spectra, in combination with chemometric modeling, result in concentration measurements that can be modeled as a function of time, allowing for interfacial mass transfer kinetic analysis. Log 131. IMPROVED MEASUREMENTS OF THORON (Rn-220) IN NATURAL WATERS. Chanyotha, S. (1); Sola, P. (2); Kritsananuwat, R. (1); Lane-Smith, D. (3); Burnett, W.C. (4). (1) Chulalongkorn University. (2) Thailand Institute of Nuclear Technology. (3) Durridge Co., Inc.. (4) Florida State University. Thoron (220Rn) in water measurements can be useful for prospecting for points of submarine groundwater discharge (SGD) into surface waters. With a 56 s half-life, any detection of thoron must mean that one is close to a source. In order to improve measurement sensitivity, we have investigated the influence of airflow rates on both radon and thoron measurements using a RAD7 detector. We observed that radon response is high and constant in the range of airflow rates from 0.5 to 2.5 L/min but drops in a linear manner at higher flows. Thoron, on the other hand, increases in response as the flow rate increases with almost a 100% increase from 0.5 to 2.5 L/min, where the response levels off. Thus, 2.5 L/min represents an optimum flow rate for measuring both radon and thoron at the same time. Field data from a coastal zone off Rayong, Thailand demonstrates that use of an external air pump circulating air at 2.5 L/min produced a thoron response 65% higher than a standard setup, reasonably close to our laboratory findings. Log 132. VALIDATION OF AN AUTOMATED CHROMATOGRAPHY DEVICE FOR ACTINIDE SEPARATION. Hardtmayer, D. (1); Co, A. (2); Xu, N. (3); Cao, L. (1). (1) Nuclear Analysis and Radiation Sensing Lab, Ohio State University. (2) Co Research Group, Department of Chemistry, The Ohio State University. (3) Los Alamos National Laboratory. An automated actinide separation instrumentation via ion exchange chromatography has been developed by Los Alamos National Laboratory and validated at The Ohio State University. An automated approach, for what is normally a manual process, for actinide separation is desired for multiple reasons, such as limiting radiation exposure to employees, improving measurement precision, and reducing the overall waste generation from the process. A device, known as the Automated Multi-Column Actinide Separation System, designed by Los Alamos National Laboratory, and fabricated by J2 Scientific, was validated by The Ohio State University for its liquid handling accuracy and chemical separation precision, including the measurement of trace elemental recoveries by inductively coupled plasma-mass spectrometry. After empirically determining that elemental recovery was possible and well within the margin of error, it was determined that AMCASS was a feasible option for automating the chromatographic process of separating actinide matrix from its trace impurities for nuclear material identification and characterization.


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Log 133. APPLICATION OF LASER SPECTROSCOPY FOR DETECTION OF ACTINIDES AND LANTHANIDES IN SOLUTIONS. I.N. Izosimov (1). (1) Joint Institute for Nuclear Research. This work is devoted to applications of the time-resolved laser-induced luminescence (TRLIF) spectroscopy and time-resolved laser-induced chemiluminescence (TRLIC) spectroscopy for detection of lanthanides and actinides. Results of the experiments on Eu, Sm, U, and Pu detection in solutions are presented. Pu, Np, and some U compounds do not produce direct luminescence in solutions, but when excited by laser radiation, they can induce chemiluminescence [1-4] of chemiluminogen (luminol in our experiments). It is shown that multi-photon schemes of chemiluminescence excitation makes chemiluminescence not only a highly sensitive, but also a highly selective tool for the detection of lanthanides/actinides in solutions. Log 134. PLUG-AND-PLAY RADIATION SENSOR COMPONENTS FOR UNMANNED AERIAL SYSTEM PLATFORM. Kazemeini, M. (1); Cook, Z. (1); Lee, J. (1); Barzilov, A. (1); Yim, W. (1). (1) University of Nevada Las Vegas. Mobile radiation sensing techniques for surge deployment and wide area search are important for nuclear security applications. Unmanned aerial systems (UAS) can be utilized as robotic platforms to carry radiation sensors. The suite of radiation sensors that can be easily attached to the robot in field conditions is required. We developed radiation sensors that are integrated into UAS as plug-and-play interchangeable components. The CLYC sensor was designed for simultaneous neutron and gamma measurements. Its electronics enables digital analysis of detector signals, including neutron/photon pulse shape discrimination with figure of merit 2.3. The ambient temperature CZT sensor was designed for high-resolution gamma spectroscopy. The spectrum is analyzed automatically, locating peaks and calculating their intensities. USB hardware connections were used for both sensors to bridge the sensors and the main controller using the UAS power source, and the Robot Operation System (ROS) was used for data communication. To streamline the process of bridging disparate components into a cohesive network, the collection of libraries describing the publisher/subscriber communication of ROS nodes was developed for these sensors. The sensor's design supports hot-plugging, and does not require a system restart. The time and position data were added via ROS to measured intensities of gamma-ray peaks and neutron rates enabling the input for the UAS flight control to search for specific sources of radiation. This method can be used for source localization as well as for mapping the radiation area. The experimental testing of the developed sensors using neutron and gamma sources is discussed. Log 135. DEVELOPMENT OF BULK URANIUM AND PLUTONIUM AGE DATING FOR NUCLEAR FORENSICS. Higginson, M.A. (1); Dawkins, B. (1); Taylor, F. (1); Kaye, P. (1), Palmer, K. (1); Heads, P. (1); Firkin, S. (1); Shaw, T. (1); King, J. (1); Huggins, T. (1); Thomas, N. (1); Knight, D. (1); Thompson, P. (1). (1) AWE Aldermaston, UK. The model age of a nuclear material is an important signature to constrain the production history of an unknown nuclear material. The age can also be used to determine links between separate samples of interest in a nuclear forensics investigation. This presentation will display the development of a uranium and plutonium age dating capability for bulk nuclear materials developed to compliment trace level age dating analysis. This work utilised vacuum assisted and automated separations, and a suite of validated analysis techniques (TIMS, ICP-MS, AS, GS, Assay) to determine the ages of materials and CRMs of known production history. The aim was to validate a rapid robust quantification scheme for plutonium and uranium materials. The methodology allows for the determination of 241-Pu/241-Am, 240-Pu/236-U, 239-Pu/235-U, 238-Pu/234-U atom ratios for bulk plutonium materials and allows comparison of chronometers in a material with model age. For uranium, the methodology allows the determination of 234-U /230-Th and 235-U/231-Pa atom ratios, with the protactinium tracer calibrated using an in-house developed TK-400 resin on column method. The materials analysed had concordant ages with known production histories, leading to the potential for expanding this work to additional chronometers.


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Log 136. SYNTHESIS AND RADIOMETRIC EVALUATION OF DIGLYCOLAMIDE FUNCTIONALIZED MESOPOROUS SILICA FOR THE CHROMATOGRPAPHIC SEPARATION OF ACTINIDES Th, Pa AND U. Hopkins, P. (1); Mastren, T. (1); Florek, J.A. (2); Copping, R. (3); Brugh, M. (1); Wilbur, D.S. (4); John, K.D. (1); Nortier, F.M. (1); Kleitz, F. (2); Birnbaum, E.R. (1); Fassbender, M.E. (1). (1) Chemistry Division, Los Alamos National Laboratory. (2) Department of Inorganic Chemistry - Functional Materials, University of Vienna, Austria. (3) Nuclear Security and Isotope Technology Division, Oak Ridge National Laboratory. (4) Department of Radiation Oncology, University of Washington,. The separation of Th, Pa, and U is of high importance in many applications including nuclear power, nuclear waste, environmental, nuclear forensics, and nuclear medicine. Diglycolamide (DGA) based resins have shown the ability to separate many elements; however, these resins have non-covalent impregnation of the DGA molecules on the resin backbone resulting in co-elution of the extraction molecule during separations, limiting its long-term and repeated use. Covalently binding the DGA molecules onto silica is one way to overcome this issue. Measured equilibrium distribution coefficients of normal extraction chromatographic DGA and a covalently bound form (KIT-6-N-DGA) are reported. Several differences are observed between the two forms. The most significant difference was observed for U, which demonstrated significantly lower sorption behavior on KIT-6-N-DGA. These results indicate that accelerator-produced U isotopes can be separated from Th and Pa using KIT-6-N-DGA, a task that could not be completed with the use of normal DGA alone. Log 137. PRELIMINARY STUDY OF PGNAA SYSTEM AT CARR. Yao, Y. (1); Xiao, C. (1); Jin, X. (1); Yun, W. (2); Shi, C. (2); Liu, X. (1); Yang, J. (1); Tang, C. (1); Wang, P. (1); Li, J. (3); Ni, B. (1). (1) China Institute of Atomic Energy. (2) Chengdu University of Technology. (3) China Institute for Radiation and Protection. As a complementary method for light elements determination of NAA, PGNAA is widely used in industrial, geological, and material science, etc. So in addition to INAA, there are two PGNAA systems with thermal and cold neutron beams that will be completely established at China advance research reactor (CARR) in 2018. Each PGNAA system consists of collimating beam tube, chopper, shutter, gamma-ray detectors, beam stop, and sample chamber with automatic changer. Herein, the height, direction, and aperture size of thermal neutron beam guide can be remotely adjusted by means of four motors. A cold neutron source was installed and tested at CARR in Oct. 2017, and preliminary PGNAA experiments were carried out at cold neutron guide. The Au-foil activation method was used to monitor the neutron flux with and without cold source. One sample can be simultaneously analyzed by two sets of detector (electric cooled HPGe with 60% relative efficiency, and LaBr3/BGO with dimensions of 3.x 3.). Additionally, the HPGe detector was surrounded by Compton suppression system (CSS) with a total of 8 BGO crystals to reduce the background, improve the detection limits, and also lower the measurement uncertainty. All detectors are coupled to ORTEC model 502 MCA operated by MAESTRO software. In 2018, cold neutron PGAA will be improved further by installing the focusing guide. Therefore, the combination of the INAA, PGAA with CSS and focusing guide can permit CIAE to enhance the capability of NAA by not only lowering the detection limits, but also by extending the scope of the elements.


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Log 138. COUPLING OF THE LIQUID SAMPLING-ATMOSPHERIC PRESSURE GLOW DISCHARGE (LS-APGD) WITH AN ORBITRAP MASS ANALYZER: A NEW PARADIGM IN ISOTOPE RATIO MASS SPECTROMETRY. Marcus, R.K. (1); Hoegg, E.D. (1); Koppenaal, D.W. (2); Manard, B.T. (3). (1) Clemson University. (2) Pacific Northwest National Laboratory. (3) Los Alamos National Laboratory. Isotope ratio mass spectrometry is an essential element in the tool boxes of both nuclear safeguards and nuclear forensics. While thermal ionization and multicollector ICP-MS are the benchmark methods, neither instrument is suitable for operation outside of pristine laboratory environments and can be suspect in terms of sample turnaround times. The liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma was initially developed for instances where rapid, in-field analyses were required. The coupling with an Orbitrap mass analyzer yielded an instrument of high sensitivity, high mass resolution, and the ability to readily meet IAEA ITVs for depleted, natural, and low-enriched uranium (high enriched not evaluated to date). While the Orbitrap is certainly not "transportable", its weight, size, and relative operational simplicity (in the commercial implementation) do allow operation in forward operating bases (FOBs) or in nuclear facilities. The ability to analyze samples in the solid, liquid, and gaseous states is particularly attractive in the face of diverse analytical challenges. The further ability to directly speciate elements (i.e., identify ligands) of interest is a powerful attribute as well. We will describe here the basic characteristics of the LS-APGD/Orbitrap instrument regarding determinations of uranium (in solution and solids) and xenon (as a gas). Representative figures of merit including isotope ratio precision and accuracy, analytical quantification, and limits of detection will be presented. It is believed that the instrument under development fills a vital void in the needs to support safeguards and forensics activities. Log 139. FAST NEUTRON IMAGING USING A SCINITLLATOR DETECTOR ARRAY. Hartman, J. (1); Barzilov, A. (1). (1) University of Nevada, Las Vegas. The application of a scintillator detector array was studied for fast neutron imaging. Computational modeling was carried out using the MCNP6 code to model source, target, and detector array geometry. The impact of and methods for reducing the cross-talk between scintillator cells in the detector array were examined. The nuclear reactions and radiation transport were studied through stochastic simulations for the plastic scintillator EJ-299-33A and CLLB crystal scintillator. Verification of computational data was done experimentally using a crystal scintillator that was attached to a SiPM array. Digital neutron / gamma pulse shape discrimination was performed in order to isolate the neutron responses. Log 140. NEUTRON ACTIVATION ANALYSIS OF MEDICINAL PLANTS. Frontaseva, M.V. (1); Vasilev, A. (1); Hristozova, G. (1); Evastatieva, L. (2). (1) Joint Institute for Nuclear Research, Dubna, Russian Federation. (2) Institute of Botany, Bulgarian Academy of Sciences, Sofia, Bulgaria. Over the past few decades, there has been a tremendous increase in the use of herbal medicine. There is still a significant lack of research data in this field. The purpose of our study is to establish a direct correlation between elemental content of medicinal plants and their curative ability, which is not yet understood in terms of modern pharmacological concept. The quantitative estimation of trace element concentrations is important for determining the effectiveness of the medicinal plants in treating various diseases and to understand their pharmacological action. Element analysis of medicinal plants can be used to decide the dosage of the herbal drugs prepared from these plants. NAA of different plants from Mongolia, India, Vietnam, Poland, Bulgaria, Portugal and Iran allowed determination of 41 elements: Na, Mg, Al, Cl, K, Ca, Sc, V, Cr, Mn, Fe, Co, Ni, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Cd, Cs, Ba, La, Hf, Ta, W, Sb, Au, Hg, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Lu, Th, and U. Such a large group of elements, for the best of our knowledge, was determined in the medicinal plants for the first time. The results are interpreted in terms of excess of such elements as Se, Cr, Ca, Fe, Ni, Mo, and rare earth elements. Thirteen dietary (Ca, Cl, Co, Fe, K, Mg, Mn, Mo, Na, Ni, S, V, Zn) and toxic elements (As, Ba, Cd, Sb) were detected. Possible connection between the medicinal properties and elemental content of the plants is discussed.


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Log 141. A NEW METHOD FOR ELUCIDATING NEUTRINO MASS IN BETA DECAY. Semkow, T.M. (1,2); Li, X. (1,2); Nishikawa, K. (1). (1) Wadsworth Center, New York State Department of Health,. (2) Department of Environmental Health Sciences, University at Albany, State University of New York. The beta spectra of familiar pure beta emitters, such as H-3, C-14, S-35, or Ni-63 carry information about the neutrino mass. Traditional methods of neutrino mass searches in beta decay are based on statistical fits of theoretical spectra to the experimental ones. In this work, a new mathematical method for elucidating neutrino mass from beta decay is developed. It is based upon transformational properties and numerical solutions of integral equations, rather than the statistical measures. Two approached are proposed. In the first approach, the experimental beta spectrum is deconvoluted from the normalized detector response function and then subjected to the Abel transformation resulting in the Abel integral equation. It is shown that the solution to this equation is a superposition of Heaviside step-functions, one for each neutrino mass eigenvalue, however, no assumptions about the neutrino mass or the number of mass eigenvalues are required. This approach has been verified by numerical calculations, which showed a fractional sensitivity of about 0.001 for heavy neutrino and can distinguish from the beta-spectrum discrepancies, such as minute shape and energy nonlinearities. In the second approach, the theoretical beta spectrum and the normalized detector response function are both convoluted in the transformed Fredholm integral equation. The matrix solution of the Fredholm equation is derived and it is shown to be also a superposition of step-functions. A numerical verification of the Fredholm equation requires a future investigation. Log 142. WHAT'S THAT YELLOW POWDER? A NUCLEAR FORENSIC CASE STUDY. Xu, N. (1); Worley, C. (1); Rim, J. (1); Rearick, M. (1); Labotka, D. (1); Green, L. (1); Walker, R. (1). (1) Los Alamos National Laboratory. In nuclear forensic case studies in which the questions of WHAT, WHEN, WHERE, and HOW need to be answered during the examination of a radioactive sample, the most important question is WHAT: what is the composition of the material? During a recent study at the Los Alamos National Laboratory, the Actinide Analytical Chemistry group encountered a legacy material described as follows: a uranium nuclear material was brought to the Group in the early 2000s. The material was a grey powder until being heated to 900oC in a furnace and turned into a light yellow color, but the mass of the radioactive material remained the same. The key question to answer is What is this material? This presentation will demonstrate that by utilizing a variety of analytical techniques including non-destructive analysis (NDA) gamma-ray spectrometry, X-Ray fluorescence, and inductively coupled plasma-optical emission spectroscopy and mass spectrometry (ICP-OES/MS) methods, we were able to put the puzzle together and answer the question. LA-UR-17-30784 Log 143. RADIOXENON PRODUCTION FROM ACTIVATION VIA D-D NEUTRON GENERATOR. S.C. Mellard (1); S. Biegalski (1); D. Haas (2). (1) Georgia Institute of Technology. (2) The University of Texas at Austin. This work shows the development of a new apparatus for radioxenon production at Georgia Institute of Technology. The neutron source is a Starfire nGen-800B with a source rate of 10E10 neutrons per second D-D (2.2 MeV). Modeling and experiments have been conducted to optimize neutron thermalization and reflection into a sample location. Models were constructed in MCNP6 and benchmarked against experiment. Experiments were conducted utilizing foils and stable Xe gas. Isotopes of radioxenon produced includes Xe125, Xe127, Xe131m, Xe133m, Xe133, and Xe135.


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Log 145. CHEMICAL AND RADIOANALYTICAL INVESTIGATIONS OF RUTHENIUM-106 IN ENVIRONMENTAL SAMPLES. Zok, D. (1); Querfeld, R. (1); Weller, A. (1); Werzi, R. (2); Degering, D. (3); Zeisler, R. U; Downing, G. R. (4) ; Steinhauser, G. (1). (1) Leibniz University Hannover. (2) CTBTO Vienna. (3) Helmholtz-Zentrum Dreseden-Rossendorf. (4) NIST Gaithersburg In October 2017, European atmospheric radionuclide measurement stations noticed the abnormal presence of Ru-106 and Ru-103 in their filter systems. Since no official statement clarified the release of these radionuclides, the source of the radioruthenium is still subject to speculations. In this study, an air filter obtained from the high-volume sampler on the roof of the Vienna International Centre, Austria, was investigated to provide more information on the chemical state of the ruthenium. This included stepwise heating of the filter material. Preliminary results suggest that the radioruthenium on the filter exhibits low volatility. This suggests that the Ru species present on the filter is not (or no longer) ruthenium tetroxide, which is the most volatile form of Ru, but also highly oxidizing. The filter will also be investigated by neutron activation analysis to check for elemental anomalies, with results currently pending. We also collected some environmental samples in the middle of October 2017 in Vienna and Hanover, including leaves from different trees as well as grass samples to estimate the deposition of Ru-106 on vegetation. Samples were gently prepared by freeze drying and hackling. In all of these environmental samples, small activity of Ru-106 were detectable and quantifiable, typically below 1 Bq/kg dry mass. Log 146. ISOLATION OF RADIOSILVER NUCLIDES FOR FORENSIC EVALUATION OF POSSIBLY DAMAGED REACTOR CORES. Zok, D. (1); Steinhauser, G. (1). (1) Leibniz University Hannover In case of a nuclear emergency, rapid information about the release and subsequent contamination of the environment is very important, as such radionuclide data allow for the quantification of the radiation hazard to human health. Typically, radionuclides such as Cs-137 and I-131 are important for the health risk assessment. However, they provide little additional information about the state of the core or the conditions inside the reactor. Radiosilver nuclides such as Ag-108m and Ag-110m may be suitable sentinel nuclides to assess the state of the neutron absorbers as silver is commonly used as a constituent of the rod cluster control assemblies in PWRs. The activation products Ag-108m and Ag-110m are both formed by neutron activation and they exhibit relatively long half-lives. Additionally, radiosilver release is a temperature regulated process and starts when the absorber rods start failing. Spectral overlap with other fission products requires the chemical separation of traces of radiosilver from the dominant background. In the present study, two methods were developed and tested for the separation of traces of radiosilver from a dominant Cs-137 background. The first method was based on the auto-deposition of silver on copper surfaces, which proved to be a cheap and easy separation method with a recovery rate of 75%. A more expensive extraction chromatographic method was developed based on the use of Eichrom's TBP and CL resin. The recovery rate were up to 95 %. The separation was successful both in deionized water as well as authentic environmental water samples.


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Log 147. DO WE REALLY NEED VERY LOW LEVEL MEASUREMENT (AMS MEASUREMENTS) FOR LONG LIFE RADIONUCLIDE IN NUCLEAR WASTE? Brennetot, R. (1); Colin, C. (1); Laporte, E. (1); Perret, P. (1). (1) Den – Service d’Etudes Analytiques et de Réactivité des Surfaces (SEARS), CEA, Université Paris-Saclay, France. Waste management is a key issue for nuclear industry. In France, Andra (French National Radioactive Waste Management Agency) is in charge of sizing, building and operating of waste repositories. In order to guarantee the security of intermediate level short live waste disposal facility (Aube disposal facility), a list of radionuclides and their maximum associated activities has been defined as acceptance criteria by Andra. From this list, some are readily and easily measured while many, such as pure beta emitters are difficult to measure, requiring long radiochemical processes. In several cases, result of the measurements carried out, after radiochemical process, with Liquid Scintillation Counting (LSC) detection technique is often under the detection limit of typically 1 Bq/g. In the lack of other data, nuclear waste producers automatically retain the detection limit as an overestimation of waste activity. Yet, to overestimate waste activities can dramatically increase the cost of their management and reduce the storage capacity of the facilities. To overcome this problem, the Operator Support Analyses Laboratory has developed new radioanalytical procedures to measure radionuclides of interest (Cl-36, I-129, Ca-41) by Accelerator Mass Spectrometry (AMS) at level as low as 1 mBq/g in nuclear waste matrices. We present here the challenges encountered to reach such activity levels. Radiochemical blank and homemade standard have been analyzed to calibrate the analytical procedure. Challenges in term of blank experiments and contamination check procedures in order to ensure such activity levels will be discussed.This work was supported by the CEA/DEN and ANDRA/R&D collaborative project DISN/ANDRA/CHK/A-CARAC-01-12. Log 148. ANALYSIS OF FOOD SAMPLES USING CERIUM BROMIDE GAMMA-RAY SPECTROMETRY. Scott, T. (1); Garnick, K. (1); Wei, C. (1); Phillips K. (2); Patil, A. (2); Persson, H. (2). (1) US FDA Winchester Engineering and Analytical Center. (2) Canberra Industries, Inc. The recently developed Cerium Bromide (CeBr) scintillation detectors are useful tools that provide the robustness of a scintillator with improved resolution over traditional Sodium Iodide (NaI) detectors. The improved resolution provides the capability of robust identification and quantification of some radionuclides of most concern, e.g., 131I, 134Cs, and 137Cs. This makes CeBr detectors attractive for field deployable or emergency response operations. Paring these inherent characteristics with the power of Monte-Carlo based efficiency determinations provides an opportunity to accurately assay a variety of sample geometries and compositions. When considering measurements of food matrices, one of the main considerations is the density of the food which has a direct impact on the attenuation of photons. Density corrections have traditionally been addressed through measuring a series of radioactive calibration standards with varying density and creating a detector specific attenuation curve. Advances in Monte Carlo based efficiency calculations can be utilized to correct for density without the need for a series of expensive calibration standards. In this work, we investigate the detection and quantification capabilities of portable CeBr scintillation detectors to assay food matrices of different densities using calculated efficiencies.


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Log 149. SIMULTANEOUS SUB-PICOGRAM SPECIATION OF MONOMETHYLMERCURY AND MONOETHYLMERCURY IN CAUSTIC NUCLEAR TANK WASTE USING DIRECT AQUEOUS PROPYLATION. Boggess, A.J. (1); Jones, M.A. (1); Bannochie, C.J. (1); Ekechukwu, A.A. (1); Wilmarth, W.R. (1); White, T.L. (1). (1) Savannah River National Laborator. The Department of Energy (DOE) Savannah River Site (SRS) in South Carolina produced radioactive materials for the nuclear weapons program that resulted in approximately 37 million gallons of radioactive liquid waste stored in under ground tanks. Part of this production process used mercury as a catalyst to accelerate the dissolution of aluminum fuel rod cladding. As a result, organomercury species are present in waste storage tanks and in the solid, cement-based waste form used to encapsulate nuclear waste for longer term storage. These species are more susceptible to leaching into the enviroment than elemental mercury and require monitoring to meet regulatory requirements. Our laboratory has developed, optimized, and internally and externally validated novel sample preparation protocols for the speciation of monomethylmercury (MeHg) and monoethylmercury (EtHg) in caustic nuclear waste using direct aqueous ethylation or propylation derivatization followed by purge and trap gas chromatography atomic fluorescence spectroscopy (GC/AFS). The details of this method including external interlaboratory comparison results are discussed in this talk. Log 150. CHEMISTRY OF ACTINIDES AND FISSION PRODUCTS WITHIN NEW POROUS FUNCTIONAL MATERIALS. Wang, S.A. (1); Wang, Y.L. (1); Wang, Y.X. (1); Xiao, C.L. (1); Chen, L. (1); Chen, L.H. (1); Sheng, D.P. (1); Liu, W. (1); Zhu, L. (1); Xie, J. (1); Bai, Z.L. (1); Diwu, J. (1); Chai, Z.F. (1). (1) School of Radiation Medicine and Protection (SRMP), School of Radiological and Interdisciplinary Sciences (RAD-X), Soochow University. During the past three years, our group in Soochow University has deeply looked into two parallel research directions, both combining two fields of radiochemistry and metal-organic frameworks (MOFs). The first one is the synthesis and characterizations of actinide MOF compounds. This system is unique not only because compared to the transition metal and lanthanide systems, the actinide based MOFs are substantially less explored, but also that these compounds cannot be simply mimicked/predicted based on those analogues of transition metals and lanthanides owing to the uniqueness of actinide ions in bonding and coordination. In addition, we have found many interesting potential applications for these compounds including actinide waste form design for geological disposal, ion-exchange for remediation of radioactive contamination, and detection of extremely low-dose ionization radiations, further highlighting the bright future of adopting actinide ions in building of unique MOFs with potential applications in the nuclear industry.1,2 The other research direction is the design and build of non-radioactive MOFs for rapid, efficient, and selective removal and detection of soluble radioisotope ions including (UO2)2+, Sr2+, Cs+, and TcO4- from aqueous solutions. Specifically, I will talk about three interesting examples within this direction: several single-crystalline zirconium phosphonate MOFs that are able to survive from fuming acids including aqua regia and can remove large amounts of uranium even from acidic solutions;3 a luminescent mesoporous MOF equipped with abundant Lewis basic sites, which can be used for sequestration and detection of trace amounts of uranyl ion in the natural water systems including seawater;4 the first experimental investigation of 99TcO4- removal by a cationic MOF material showing many promises over the traditional anion-exchange materials.5 These works clearly reveal that all the possible advantages for ideal radioisotope sorbent materials including high capacity, fast kinetics, excellent selectivity, and great stability and recyclability etc. can be indeed integrated in the MOF system.


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Log 151. INVENTORY OF 129I IN BRACKISH LAKE SEDIMENTS ADJACENT TO A SPENT NUCLEAR FUEL REPROCESSING PLANT, JAPAN. Ueda, S. (1); Kakiuchi, H. (1); Hisamatsu, S. (1). (1) Institute for Environmental Sciences, Japan. In order to clarify the 129I inventory in sediment of brackish Lake Obuchi adjacent to a commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan, concentrations of 129I in lake sediments were measured from 2006 to 2016. The plant is now under final safety assessment by a national authority after test operation using actual spent nuclear fuel. During cutting and chemical processing in the test operation from April 2006 to October 2008, 129I was discharged to the atmosphere and ocean. We already reported that the 129I concentration in lake water and aquatic biota increased during the processing followed by prompt declining after it. The 129I concentration and 129I/127I atomic ratio in the sediment of Lake Obuchi increased to the order of 1E-8 - 1E-6 Bq/g-dry and 1E-10 - 1E-9, respectively, with the maximum values one order of magnitudes higher than the levels before the processing. The inventories of 129I in lake sediments rose until the end of the processing in 2008, and have maintained the increased level of approximately 20-30 mBq/m² until 2016. The possible reasons for the nearly constant 129I inventories are negligible 129I elution from the sediment and/or continuous supplying 129I from the catchment area in equivalent to the eluted 129I. "This study was performed under a contract with the government of Aomori Prefecture, Japan." Log 152. SELECTIVE REMOVAL OF U AND Th FROM RARE EARTH ELEMENTS LEACHING SOLUTION USING MAGNETIC SOLID-PHASE EXTRACTION. Whitty-Léveillé, L. (1, 2); Reynier, N. (1, 2); Larivière, D. (1). (1) Université Laval. (2) Natural Resources Canada. Recently, the recovery of rare earth elements (REE) from a variety of resources has gained much interest. As actinides and REE share similar chemical properties, the separation of those two groups of elements is often a concern in the rare earth industry in order to manage radioactive contamination, but also because of the chemical challenge it poses. The partitioning of actinides and lanthanides is the most challenging hydrometallurgical separation known. The present study highlights a new type of extracting process using magnetic solid-phase support and Schiff base ligands, which were entirely synthesized and characterized for the study. The effect of extraction parameters (pH, mass of ligand, and time) was investigated and optimized. It was found that the maximum capacity of the magnetic Schiff base towards actinides is 52.04 mg g-1 and 79.20 mg g-1 for U(VI) and Th(IV), respectively, obtained at pH = 6 with only 25 mg of extracting agent for a contact period of 24 h. The magnetic ligand has also showed incredible selectivity to extract U(VI) over more than 45 metals in a real REE leaching solution. Log 153. DEVELOPING REALISTIC SAMPLES TO SIMULATE NUCLEAR AND RADIOLOGICAL EVENTS. Tamasi, A.L.(1). (1) National Analytical Radiation Environmental Laboratory. It is imperative that the effectiveness and reliability of the science employed during nuclear and radiological incident response be tested, and a cornerstone of that effort is having realistic simulated materials of known composition against which to test. The current variety and availability of these materials, both for a post-detonation nuclear scenario and for radiological dispersal scenarios, will be explored. Further, the considerations for taking a new simulated material and turning it into an effective and reliable benchmark for assessing laboratory capabilities and rapid analysis protocols will be discussed in the context of EPA's planned future effort to make available simulated radiological urban matrix materials to enable inter-comparison studies amongst state and/or federal labs.


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Log 154. 4H-SiC ALPHA SPECTROSCOPY FOR NUCLEAR FORENSICS WITH ELECTRODEPOSITED SOURCES. Jarrell, J. (1); Stika, M. (2); Blue, T. (1); Simpson, M. (2), Cao, L. (1). (1) The Ohio State University. (2) University of Utah. Actinides possess characteristic alpha emissions which can be used to identify unique isotopes. Actinides such as thorium and uranium are members of decay chains comprising multiple alpha emitting actinides. The isotopic composition of a sample can provide information on the history of fabrication, separation, and the originating source of the sample. Electrodeposition allows for the separation of elements of interest based on their electronegativity. Thus, sources can be fabricated which isolate actinides from their daughter products which arise in their decay chain. A 4H-SiC alpha detector was used to identify the daughter isotopes in the thorium and uranium decay chain. A Th-230 peak was observed in the alpha spectrum from the electrodeposited thorium source. Th-230 is present in the U-238 decay chain indicating that the thorium which was used for the electrodeposited source must have been obtained from a mineral that contained both uranium and thorium. Chemical separation of uranium and thorium from the source mineral ore introduces Th-230 as an inclusion with the Th-232 found in the mineral and subsequently in the fabricated electrodeposited thorium source. A depleted uranium source was fabricated by electrodeposition in molten salt. The resulting spectrum showed a U-234 peak which provides information about the enrichment process. Given the slow build in of U-234, information concerning the enrichment process used is preserved allowing for investigation of enrichment activities long after the actual enrichment has occurred. Log 155. IONIC LIQUIDS AS POTENTIAL ELECTROLYTE SOLVENTS FOR LITHIUM BATTERIES IN RADIOACTIVE ENVIRONMENTS. Tan, C. (1); Thio, W.J. (2), Glover, J.L. (3); Lyons, D.J. (3); Cao, L.R. (1); Co, A.C. (3). (1) Nuclear Engineering, The Ohio State University. (2) Electrical Engineering, The Ohio State University. (3) Chemistry and Biochemistry, The Ohio State University. Conventional organic electrolyte used in Li ion batteries (LIBs), e.g., 1 M LiPF6 in EC:DMC 1:1 wt%, suffers from high degree of decomposition by direct gamma radiation as well as radiation facilitated hydrolysis. While the goal of this study is to seek an electrolyte that overcomes the drawbacks of conventional electrolyte during and after irradiation, it is also important to avoid developing complex configurations and fabrication methods that only serve the purpose of batteries used in radiation environments. Therefore, ionic-liquid-based liquid electrolyte was examined by using gamma radiation produced by a Co-60 irradiator located at the Ohio State University Nuclear Reactor Lab with a dose rate of 29 krad/h. Ionic liquids (ILs), also called room temperature molten salts, offer low melting point, negligible vapor pressure, good thermal and chemical stability, and resistance to air and moisture compared to conventional organic liquid solvents. EMITFSI, with a cation of ethyl-methyl-imidazolium (EMI+) and an anion of bis-(trifluoromethyl-sulfonyl)-imide (TFSI-), was irradiated for 7 days (4.9 Mrad). After irradiation, the EMITFSI sample gradually developed a strong discoloration compared to a clear, transparent control sample. Decomposition products due to irradiation were characterized using gas chromatography-mass spectroscopy (GC-MS) and compared to irradiated conventional organic electrolyte. Later, LIB coin cells assembled with EMITFSI-based electrolyte before and after irradiation were cycled using C/20 current (~0.01 mA). Briefly, irradiated EMITFSI has less decomposition products and batteries equipped with 225-day old irradiated EMITFSI electrolyte still delivered good charge/discharge capacity. Therefore, ionic liquids were proved capable of operating in radiation filled environments.


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Log 156. RAPID DISSOLUTION OF SURROGATE NUCLEAR DEBRIS USING AMMONIUM BIFLURORIDE FUSION AND INDIRECT SONICATION DISSOLUTION METHODS. Hubley, N.T. (1,2); Wegge, D.L. (1); Brockman, J.D. (1); Liebman C.P. (2); Rearick, M.S. (2); Robertson, J.D. (1). (1) University of Missouri-Columbia. (2) Los Alamos National Laboratory. Prompt analysis of elemental and isotopic information from post detonation nuclear debris is critical for rapid attribution analysis. Conventional acid dissolution techniques used for dissolving bulk nuclear debris samples can take days to complete. In this work, we report on the capability of two dissolution methods that use the fluorinating agent ammonium bifluoride (ABF), NH4HF2 as means to rapidly dissolve debris samples. The first method is an open vessel fusion with ABF at 230 .C in PFA tubes. The work includes evaluation of a novel mechanically assisted ABF fusion technique. Following the fusion the samples are taken to dryness with boric acid to eliminate insoluble fluorides. The second method utilizes in-direct sonication of the sample at 55 °C with ABF and concentrated nitric acid in capped polypropylene tubes. The dissolution methods are being evaluated with ICP-MS to measure elemental recovery from geological materials and the candidate reference material NIST Surrogate Post-detonation Urban Nuclear Debris (SPUD). Prior to dissolution, a sample of the SPUD material is being analyzed using instrumental neutron activation analysis (INAA). The recovery from the ABF fusion and indirect sonication dissolution methods will be compared with the INAA results and conventional microwave digestion using nitric acid and hydrofluoric acid. LA-UR-17-30394 Log 157. DEVELOPMENT OF A NUCLEAR FORENSICS LEXICON. Stratz, S.A. (1). (1) U.S. Department of Energy. A nuclear forensics lexicon was developed to facilitate common acceptance of terms within the interagency community. This work presents the need for such a lexicon to exist and demonstrates the procedure used for lexicon compilation. Log 158. MOLECULAR FORMATION IN CONDENSING LASER ABLATION PLASMAS. Weisz, D.G. (1); Crowhurst, J.C. (1); Finko, M.S. (2); Rose, T.P. (1); Koroglu, B. (1); Trappitsch, R. (1); Radousky, H.B. (1); Siekhaus, W J. (1); Armstrong, M.R. (1); Isselhardt, B.H. (1); Azer, M. (2); Curreli, D. (2). (1) Lawrence Livermore National Laboratory. (2) University of Illinois at Urbana-Champaign. The formation of UOx and other molecular species in nuclear fireball environments is controlled by multiple parameters, including temperature and fireball composition. Understanding how these parameters control high-temperature molecular formation is important to constraining vapor-phase fractionation, which affects post-detonation debris composition. In this work, we study competitive molecular formation of multiple species during plasma condensation for the purposes of improving post-detonation debris formation models. To observe high-temperature molecular formation, we used pulsed laser ablation (5-10 ns pulse length) to form plasma conditions from multi-component targets, and identified vibronic molecular bands in time-resolved emission spectra. Further, 2D images were acquired to observe the spatial distribution of molecules in the laser ablation plume. Time-resolved emission spectra were acquired using an intensified CCD (ICCD) coupled to a grating spectrometer, and plume images were acquired using the ICCD in conjunction with narrow bandpass filters specific to molecular emission wavelengths of interest. These data were consistent with a kinetics-based, semi-empirical computational model, which can be used as a predictive tool to inform fractionation studies in post-detonation systems. LLNL-ABS-742544


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Log 159. WELCOMING E-LEARNING INTO MIRION'S TRAINING PROGRAM IN THE NUCLEAR MEASUREMENT INDUSTRY. Conway, H. (1). (1) Mirion Technologies Inc. Traditionally, training in the nuclear measurement industry involved either a student traveling to a facility to be taught, or an instructor traveling to a customer's site to teach a course. In this digital age, training is no longer restricted to these brick and mortar options. A new form of training, where the course is available to the student wherever they can connect to the internet, is done through e-learning. In this paper, we will discuss how we have, and still are, making strides to design training that is attainable for everyone in our industry. Log 160. HOMOGENIZATION OF FOOD SAMPLES FOR GAMMA SPECTROMETRY USING PROTEASE. Nishikawa, K.C. (1); Bari, A. (1); Khan, A.J. (1); Li, X. (1); Menia, T. (1); Semkow, T.M. (1,2). (1) Wadsworth Center, New York State Department of Health. (2) University at Albany, State University of New York. Methods of food sample preparation for gamma spectrometry commonly used for routine monitoring would have a number of limitations during a radiological emergency. Chopping may not ensure complete sample homogenization, and blending may contaminate a large amount of laboratory equipment that is difficult and time-consuming to clean. We previously reported a method aimed at developing best compromises between degree of homogenization, accuracy, speed, and minimizing laboratory equipment contamination. This method involves the use of tetramethylammonium hydroxide (TMAH) and/or enzymes such as alpha-amylase or cellulase for sample homogenization. We now propose an additional method using the protease bromelain that can homogenize samples in ~1 h without high heat or harsh chemicals. This method is useful for meats as well composite meals containing both meat and starch. We demonstrated the effectiveness of this method using food matrices spiked with the radionuclides Co-60, I-131, Cs-134,137, and Am-241. Based on calculated sample biases and z-scores, our results suggest that homogenization with bromelain would be a useful method for preparing meat and composite meal samples for gamma spectrometry analysis during radiological emergencies.


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Log 161. INVESTIGATING THE TEMPORAL VARIATIONS OF PLUTONIUM ULTRA-TRACE CONCENTRATIONS AND ISOTOPIC COMPOSITIONS IN RIVER AND DAM SEDIMENT IN THE FUKUSHIMA PREFECTURE BY MC-ICP-MS. Jaegler, H. (1); Pointurier, F. (2); Onda, Y. (3); Hayashi, S. (4); Tsuji, H. (4); Hubert, A. (2); Laceby, P.J. (1,5); Evrard, O. (1). (1) Laboratoire des Sciences du Climat et de l'Environnement (LSCE, joint laboratory CEA/CNRS/UVSQ), France . (2) CEA, DAM, DIF, France (3) Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan. (4) National Institute for Environmental Science, Fukushima Branch, Japan. (5) Environmental Monitoring and Science Division, Alberta Environment and Parks, Canada. The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident led to the formation of a radioactive pollution plume in soils of Northeastern Japan. Trace levels of plutonium have been detected in environmental samples collected in the vicinity of FDNPP. However, little is known about both the temporal and spatial variations of the plutonium contamination from FDNPP. Here, we used a Multi-Collection Inductively Coupled Mass Spectrometer (MC-ICP-MS) to detect plutonium isotopes (i.e. 239Pu, 240Pu, 241Pu and 242Pu). This instrument allows precise and accurate measurements of plutonium atom ratios and concentrations at ultra-trace levels. Plutonium was measured in river sediment deposits (n=11) collected between November 2011 and November 2014, and in several layers (n=7) of a dam sediment core. In the river sediment, plutonium concentrations and isotopic ratios (240Pu/239Pu, 241Pu/242Pu and 242Pu/239Pu) generally decreased between 2011 and 2014, when they reached values close to those reported for the global fallout. This temporal evolution confirmed the fast export of sediment by heavy floods and the impact of decontamination works. In the dam sediment core, the maximum value for all the plutonium isotopic ratios was identified at 10 cm depth, corresponding to a maximum contribution of 4.8 +/- 1.0% of plutonium from the FDNPP. This maximum coincides with the highest 137Cs concentrations and likely corresponds to sediment that was deposited shortly after the FDNPP accident. The analysis of sediment located in the bottom part of the core will contribute to improving the quantification of the plutonium global fallout signature in this region of the world, whereas sediment collected in the top of the core will help understand post-fallout plutonium dynamics in the region. Log 162. TRACE ELEMENTS IN URANIUM BENCHMARKING STUDY - EMPHASIS ON HPLC-ID-ICP-MS METHODOLOGY. Manard, B.T. (1); Wylie, E.M. (1); Xu, N. (1); Montoya, D. (1); Aragon, S.M. (1); Rearick, M.S. (1); Schappert, M.F. (1); Tandon, L. (1). (1) Los Alamos National Laboratory. A benchmarking study was performed in which three unknown uranium samples were analyzed for their trace element compositions. These test materials were designed to mimic pre-detonation nuclear forensic event. The purpose of this study was to utilize existing measurement methodologies employed currently within the actinide analytical chemistry (C-AAC) group at Los Alamos National Laboratory (LANL) that have previously been submitted to the Department of Homeland Security (DHS). In addition, a new methodology to the C-AAC group, high performance liquid chromatography - isotope dilution - inductively coupled plasma - mass spectrometry (HPLC-ID-ICP-MS) was employed. Besides the discussion on sample processing and trace elemental analysis by traditional methods, for the talk will emphasize on the HPLC-ID-ICP-MS method and how it is compared to the established methods.


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Log 163. TIME MODULATED IMAGING OF GAMMA RAYS AND NEUTRONS USING CLYC DETECTOR WITH A DUAL-MATERIAL COLLIMATOR. Barzilov, A. (1); Guckes, A. (1). (1) University of Nevada Las Vegas. Directional information about radiation sources in a simultaneous measurement of gamma rays and neutrons is essential for many radiation detector applications. The detection system that is capable of imaging radioactive sources in two dimensions was developed. The detection medium is a single CLYC scintillator enriched in Li-7. The detector is equipped with a cylindrical heterogeneous collimator composed of ABS plastic and lead. A coded aperture is inlaid in the collimator using these materials. To enable the time-encoded imaging of a radioactive source, the dual-material collimator is rotated 360 degrees. The neutron and photon measurements are taken in discrete time steps that correlate to the angular rotation of the collimator. The radiation measurement data are convoluted using a decoding mask of the coded aperture to create an image of a radioactive source. This collimator design allows for the directional detection of gamma rays and fast neutrons by utilizing only one scintillator. Moreover, the system is capable of pulse shape discrimination of photons and fast neutrons and gamma spectroscopy. The detector was tested by performing directional measurements using various gamma-ray and neutron sources. Log 164. SPECIATION OF URANIUM IN GROUNDWATER IN THE PRESENCE OF NATURAL ORGANIC MATTER. Jung, E.C. (1); Baik, M.H. (1); Cho, H.-R. (1); Kim, H. (1); Cha, W. (1). (1) Korea Atomic Energy Research Institute Time-resolved laser fluorescence spectroscopy was primarily used for the chemical speciation of U(VI) (hexavalent uranium) complexes and natural organic matter (NOM) in groundwater. Groundwater was sampled from a borehole with a depth of 500 m in granite rocks located at the underground research tunnel constructed in the research area of KAERI (Korea Atomic Energy Research Institute) in Daejeon, Korea. The luminescence characteristics (peak wavelength in spectrum and lifetime of excited state) of U(VI) in the groundwater agree well with those of neutral dicalcium uranyl tricarbonate species in a standard solution prepared in a laboratory. It was observed that the luminescence intensities of U(VI) species were significantly enhanced at low temperatures (one degree Celsius in this study). By contrast, an increase in the luminescence intensities of NOMs was indistinctive at low temperatures. Thus, the spectral overlap between NOM and U(VI) in groundwater was avoided by performing the luminescence measurement at low temperatures. In the presence of NOM, the luminescence intensities of U(VI) in the groundwater were weaker than those of a neutral dicalcium uranyl tricarbonate complex in the standard solution at the same uranium concentrations. This result can be ascribed to U(VI) species interacting with NOM and forming non-radiative U(VI) complexes in groundwater. Excitation emission matrix fluorescence spectroscopy was applied to characterize the NOMs. The mean positions of excitation and emission maxima were observed at 270 and 295 nm, respectively. The origin of NOMs in groundwater will be discussed based on these results.


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Log 165. RADIOANALYTICAL INVESTIGATIONS OF WATER SAMPLES FROM FUKUSHIMA. Querfeld, R. (1); Shozugawa, K. (2); Hori, M. (3); Degering, D. (4); Steinhauser, G. (1). (1) Leibniz University Hannover, Institute of Radioecology and Radiation Protection. (2) The University of Tokyo, Graduate School of Art and Sciences. (3) The University of Tokyo, Komaba Organization for Educational Excellence. (4) VKTA-Analytik & Entsorgung Rossendorf e.V. Two different types of samples were used for investigations. First, surface water samples, which were collected at April 10, 2011, only one month after the triple-disaster in Fukushima. The samples were collected at various places in Fukushima prefecture, in different distances from and directions to Fukushima Daiichi NPP (FDNPP). They were filtered prior to radioanalysis. The second type of sample material included tap and surface water samples from the prospective locations of the 2020 Olympic Summer Games. The sampling took place in 2016. Isotopes of interest were H-3, Sr-90, I-129, Cs-134, and Cs-137. The Cs-isotopes were measured by gamma spectrometry (HPGe), no pretreatment was deemed necessary. Measurements of tap water samples were performed by low-level gamma spectrometry in an underground laboratory (Felsenkeller, Germany). For the measurement of Sr-90, the water samples were pretreated by SPE extraction. Tritium was separated from disturbing ions and radionuclides by distillation. Afterwards, the activities were determined by using LSC (HIDEX 300SL). Iodine-129 required a more laborious pre-treatment; samples were measured by AMS facilities in Zurich and Vienna. First results of the surface water samples show the highest activities in sampling locations closest to FDNPP. One of the most remarkable results was the presence of H-3 in a couple of samples in detectable activities. In the "Olympic" tap water samples, detection limits of Cs-137 were in the range of 3 mBq/L, howeve, this low detection limit was exceeded only in one case. Other isotopes will be determined in near future and presented at MARC XI. Log 166. TESTING AND OPTIMIZING PVT SCINTILLATORS FOR FAST NEUTRON IMAGING. Chuirazzi, W.C. (1); Oksuz, I. (1); Massey, T.N. (2); Brune, C.R. (2); Cherepy, N.J. (3); Cao, L.R. (1). (1) The Ohio State University. (2) Ohio University. (3) Lawrence Livermore National Laboratory. Fast neutron imaging offers high penetration and decreased activation concerns. The low interaction cross sections of fast neutrons require development of an efficient scintillator material. Polyvinyltoluene (PVT) scintillators were evaluated to determine how fluorescent dopants and scintillator configurations could optimize PVT for fast neutron imaging. A neutron imaging apparatus was created, using a cooled EMCCD camera and single mirror reflection, to capture images and study scintillators' response under fast neutron exposure. Scintillators were exposed to a neutron spectrum with a maximum energy of 3.2 MeV produced by a particle accelerator. A nuclear reactor based neutron beam facility at The Ohio State University was also used to provide ~ 1MeV fast neutrons at the order of 104 cm-2s-1. PVT was doped with different fluors and the respective light yields were measured. Loading PVT with 2% of an X-Flrpic fluorescent created the largest increase in photon production. PVT scintillator packaging configurations were tested to determine their effects on spatial resolution and light yield. The addition of a black backing to the scintillator, compared with a specular film backing, improved the resolution of the neutron image obtained with the PVT scintillator by 120%. This study recommends PVT be doped with 2% X-Flrpic and configured with a black backing to have an optimized efficiency and spatial resolution for fast neutron imaging. Neutron radiography and tomography of a few phantoms will also be presented.


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Log 167. THEORETICAL APPROACHES TOWARD HIGH EFFICIENT SEPARATION OF An(III) OVER Ln(III). Weiqun, S. (1); Qunyan, W. (1); Congzhi, W. (1); Jianhui, L. (1). (1) Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, China. With the rapid advancement of nuclear power industry, reprocessing of spent nuclear fuels has been attracting many concerns owing to the big challenge for waste treatment and efficient recovery of all actinides, especially minor actinides (MAs). Among which, the issue related with the group separation of actinides over Ln(III) has not been appropriately solved due to the chemical similarity of An(III) and Ln(III) and the harsh separation condition which often causes the vulnerability of ligands. In this work, the design criteria for dedicated ligands with respect to the Am(III)/Eu(III) separation will be introduced. The effect of ligand structural rigidity, the strategy of N, O-donor combination will be also discussed. We did eventually obtained a high efficient ligand which displayed exceptional group actinide extraction ability in solvent extraction experiments. Log 168. CHEMICAL SPECIATION OF URANIUM IN ELECTRO-DEPOSITION PROCESS IN LiCl-KCl MELT: AN EXAFS AND UV-VIS SPECTROSCOPIC STUDY. Weiqun, S. (1); Yalan, L. (1); Benlin, Y. (1); Zhifang, C. (1). (1) Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences, China. In this work, the chemical speciation transformation of uranium in the electrodeposition process in LiCl-KCl melt on different electrodes was systematically studied by EXAFS and solid UV-Vis techniques. It was found that after the chlorination of UO2 assisted by AlCl3, the predominant complex of uranium in melt is [UCl6]2-. When the electro-deposition was carried out on an Al electrode, the prevalent speciation of uranium in melt was quickly transformed into [UCl6]3-, and then changed back to [UCl6]2-. For comparison, the electro-deposition of uranium was also implemented on both Al and Zr cathodes. Our work can afford insightful information for better achieve the so-called exhaustive electrolysis with respect to the recovery of actinides and purification of molten salt. Log 169. INVESTIGATION OF COLLOID SORPTION BEHAVIOR OF CESIUM IN CRUSHED GRANITE USING BATCH TESTS. Shih, Y.H. (1); Chen, L.-C. (1); Tsai , T.-L. (1); Lee, C.-P. (2); Tsai, S.-C. (3); Su, T.-Y. (1). (1) Institute of Nuclear Energy Research. (2) National Cheng Kung University. (3) National Tsing Hua University. Recent research demonstrated that colloid can sorb radionuclides and accelerate the migration rate of radionuclides under the suitable environment. Therefore, an understanding of the effect of colloids on the sorption of radionuclides in rock fracture and groundwater play a prominent role in establishing the geological data of final disposal sites. In addition to characterization analysis and stability test for colloid sorption behavior include, the effects of bentonite colloids on the sorption of radionuclide (Cs-137) with crushed granite from Taiwan crystalline test area were performed in this study, which is used as reference of performance and safety assessment of final disposal. The results showed that , the radionuclide (Cs-137) can be easily retarded (adsorbed) on the surface of the crushed rock in a colloid-free environment from the batch experiment. However, radionuclide (Cs-137) will adsorb on bentonite colloids and easily facilitate the transport of radionuclide with groundwater in the presence of colloids.


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Log 170. ALPHA SPECTROMETRY FOR BASIC CHARACTERIZATION OF NUCLEAR FORENSIC SAMPLES. Hudston, L.A. (1); LaMont, S.P. (1); Harris, M.N. (1); Dry, D.E. (1); Steiner, R.E. (1); Atoyan, V. (2); Pyuskyulyan, K. (2); Dallas, L. (3). (1) LANL. (2) Armenia Nuclear Power Plant. (3) NNSA. Nuclear forensic evidence examinations are used to identify and quantify nuclear and radioactive materials recovered from outside of regulatory control, provide necessary evidence for prosecuting criminal activity, and ultimately help determine the provenance of the material. As part of an ongoing collaborative project between the United States and Armenia, we are working to demonstrate how alpha spectrometry can contribute to nuclear forensics examinations and produce reliable and defensible uranium enrichment data. Gamma-ray spectrometry is frequently used to determine uranium enrichment, but can be challenging for forensic samples that are often in non-standard counting geometries and require self-absorption corrections that make estimating enrichment difficult for laboratories that do not routinely practice these measurements. Given the serious nature of incidents involving enriched uranium, and the relatively ubiquitous nature of depleted and natural uranium materials, it is critical that accurate enrichment data is available to investigators, and gamma-ray spectrometry data may not easily provide an accurate measure of enrichment. As a compliment to gamma-ray spectrometry, alpha spectrometry can provide reasonably accurate uranium enrichment measurements that are generally much easier to interpret. There are a number of other advantages to employing alpha spectrometry as well, including the relatively low cost of equipment, robust nature of the hardware, its ease of operation, and straightforward data interpretation. The disadvantage is that samples generally cannot be counted directly, and need to be prepared into thin sources with limited self-absorption. However, there are a number of source preparation techniques that require only basic radiochemistry expertise and produce data sufficient for estimating uranium enrichment. This paper will discuss the training materials developed for applying alpha spectrometry to nuclear forensic investigations along with methods for preparing samples and evaluating data to determine uranium enrichment. Log 171. SUPPORTING HIGH-SCHOOL-TEACHERS IN THE FIELD OF RADIOCHEMISTRY AND RADIATION PROTECTION. Friege, G. (1); Vahlbruch, J.-W (1). (1) Leibniz University of Hannover. Performing experiments plays a major role in scientific research as well as in science teaching. Experiments offer the potential to motivate students and enable personal experiences in the process of scientific discoveries. This applies, of course, also to experiments concerning ionizing radiation - a topic that has been implemented in the curriculum of the 9th and 12th grade. However, numerous experiments, especially in the field of radioactivity, are no longer performed in high-school classes due to restrictions concerning the handling of radioactive sources or due to missing concepts. At Leibniz University of Hanover a package of measures was initiated with the aim to encourage and support teachers to handle radioactive material or at least to deal with these topics in their lessons. The main activities are a custom-tailored, certificated radiation protection course only for students of education and the implementation of real experiments with naturally occurring radioactive material with low activities. This contribution presents and discusses these measures in detail and presents additionally a new developed virtual reality experiment to determine the half-live of Ba-137m.


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Log 172. MEET-CINCH - A MODULAR EUROPEAN EDUCATION AND TRAINING CONCEPT IN NUCLEAR AND RADIO CHEMISTRY. Vahlbruch, J.-W. (1); Friege, G (1). (1) Leibniz University of Hannover The MEET-CINCH project, supported within HORIZON 2020, follows two previous projects (CINCH I and II) with the aim to foster Education and Training in the field of Nuclear and Radio Chemistry and to sustain the results obtained in CINCH I and II. In this contribution, the main aims and objectives of MEET-CINCH like attracting new talents to the nuclear field and providing a comprehensive tool-kit to support the education and training in the field of nuclear and radiochemistry are presented and discussed. Special attention will be given to new learning-forms like remote controlled experiments (Robo-Labs) and the development of an MOOC (Massive Open Online Course) in order to increase the awareness and the number of students that select a career path in the nuclear and radiochemistry sector. The design and implementation of a modern Flipped Classroom (Inverted Classroom) concept for regular university courses in chemistry or physics that will complement the available tools for teaching and training in the nuclear and radiochemistry field will be also discussed. Additionally, the development of a teaching package aimed for use in highschools for 16-18-year-old pupils and the design of a new platform (the CINCH VET e-shop) that will provide easy access to and details of all courses offered by CINCH will be presented. Log 173. HOMOGENEITY ASSESSMENT OF STANDARD REFERENCE MATERIALS (SRMS) 4600 AND 4601: SURROGATE POST-DETONATION URBAN DEBRIS (SPUD) MATERIALS. Mann, J.L. (1); Molloy, J.L. (1); Tyra, M.A. (1); Buscaglia, J. (2); Leggitt, J. (2); Pfeuffer, K.P. (3); Fallon B.L. (3); Jerome, S. (4). (1) NIST. (2) FBI Laboratory. (3) ORISE/FBI Laboratory. (4) NPL. One priority for any reference material producer is supplying suitably homogeneous materials, with suitability driven by the instrumental methods and applications of the measurement community/customer. A homogeneous reference material is required to achieve comparability between measurement communities and ensures certified values assigned to a material are applicable at the sample sizes being used. A combination Principal Component Analysis and microbeam X-ray fluorescence spectroscopy method was used to assess the homogeneity of two surrogate post-detonation urban debris materials: SRM 4600 (natural Uranium) and SRM 4601 (highly-enriched Uranium). For SRM 4600, 400 spectra, each representative of a 400 µm diameter analysis area, were summed together and combined with the calculated penetration depth and sample density. The result was an estimate of the minimum sample mass required for the entire SRM where sample heterogeneity is not a significant contributor to the uncertainty of assigned values. The minimum sample mass determined is approximately 25 mg. The homogeneity assessment methodology and results for both SRMs will be presented and subsequent discussion will detail the challenges encountered assessing certain elements due to long term signal drift.


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Log 175. DOE TRAINEESHIP IN NUCLEAR AND RADIOCHEMISTRY AT WASHINGTON STATE UNIVERSITY AND COLORADO SCHOOL OF MINES. Wall, N.A. (1); Jensen, M.P. (2); Nash, K. (1); Wall, D.E. (1); Clark, S.B. (1); Braley, J. (2). (1) Washington State University. (2) Colorado School of Mines. The joint WSU-CSM radiochemistry DOE traineeship program in nuclear and radiochemistry, established in 2016, is developing a new generation of highly-skilled radiochemists with expertise focused on national needs. The traineeship enhances the quality and depth of the two first years of graduate school for the selected students. The selected students can take two-way coursework offered at the partner university on subjects pertaining to nuclear sciences. The trainees also participate to yearly multi-day professional development workshops, organized by the partner universities. The students initiate research projects in radiochemistry at their home university and in collaboration with a member of the technical staff at a national laboratory (Idaho, Lawrence Livermore, and Pacific Northwest) and complete internships at the partner national laboratory, where they are exposed to national laboratory practices. The partnerships with these three different national laboratories allow for offering a variety of research subjects related to nuclear energy, the environment, and national security. Funds are also available for trainees to present their work at conferences. Furthermore, scientists with relevant research and professional expertise are invited to visit each university to communicate with the trainees. This unique program allows to attract new graduate students to a career in radiochemistry and provides them with tools for a successful graduate program and future career. This work was funded by the U.S. Department of Energy, under the award number DE-NE0008582 Log 176. COMPLEXATION OF Tc(IV) WITH SULFATE IN NaCl MEDIUM. Wall, D.E. (1); Parker, T.G. (2); Omoto, T.S. (2); Wall, N.A. (2). (1) Nuclear Science Center, Washington State University, Pullman (2) Department of Chemistry, Washington State University. The isotope Tc-99 is of particular interest because of its presence in spent nuclear fuel (SNF) reprocessing waste streams, tank wastes at the Hanford site, and some contaminated subsurface environments. While Tc(VII) is the predominant oxidation state in oxidizing and oxic environments, Tc(IV) forms sparingly soluble oxides (e.g. TcO2•xH2O) under anoxic or reducing condition. However, ligand complexation can stabilize the Tc(IV) oxidation state relative to Tc(VII) and increase Tc(IV) solubility in aqueous media. Stability constants have been determined for Tc(IV) with bicarbonate, acetate, oxalate, citrate, and EDTA; there is a need for data pertaining to Tc(IV) complexes with halides. This work reports the experimental determination of the stability constant for the complexation of the TcO(OH)+ cation by sulfate at 1.0 m ionic strength (NaCl) and pcH 1.51 ± 0.05 using a solvent extraction method. Radiotracer studies were carried out with Tc-99 and S-35 using both HDEHP and TOPO as extractants to characterize the mechanism of the solvent extraction and to examine the extraction of the competing species, TcO(HSO4)+ and TcOSO4, into the organic phase. The apparent stability constant (in log10 unit) for the complexation of Tc(IV) by sulfate was found to be 1.13 ± 0.04.


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Log 177. THERMODYNAMIC PARAMETERS FOR THE COMPLEXATION OF Tc(IV) WITH EDTA. Friend, M.T. (1); Lledo Eiroa, C. (1); Lecrivain, L.M. (1); Wall, D.E. (1); Wall, N.A (1). (1) Department of Chemistry, Washington State University. Technetium 99 is a high yield (~6% isobaric fission yield) fission product and long lived (213,000 year half life) component of high level nuclear waste. This isotope has already been released into the environment as a result of nuclear fuel and weapon production activities at sites such as Hanford, WA. Under reducing conditions, Tc can be present in the tetravalent oxidation state which forms sparingly soluble cationic species. However, the presence of organic chelating agents such as EDTA can form aqueous complexes with Tc(IV), increasing its solubility, and therefore, its environmental mobility. This work presents the experimental determination of the thermodynamic parameters that describe the complexation of Tc(IV) with EDTA using a radiotracer solvent extraction technique. Two Tc(IV)/EDTA complexes where identified as TcOEDTA2. and the protonated complex, TcO(HEDTA)., and their respective stability constants were measured. The associated .rG, .rH, and .rS were determined with vant Hoff analyses at 15 45 °C. Speciation models using the measured stability constants indicated that TcO(HEDTA). is the prevalent solution species of Tc(IV) at pCH 2, shifting to TcOEDTA2. as the pCH increases to 5.5. Hydrolyzed Tc(IV) species were found to dominate at pCH > 5.5. These data are important for prediction of increased solubility and ligand facilitated environmental mobility of Tc(IV). This work was funded by the U.S. National Nuclear Security Administration, under the SSAA Grant DE-NA0002916. Log 178. COMPLEXATION OF ZIRCONIUM(IV) WITH EDTA AND CDTA FOR MANAGING ZIRCONIUM IN USED NUCLEAR FUEL REPROCESSING. Friend, M. (1); Wall, N.A (1). (1) Washington State University. Reprocessing and recycling of used nuclear fuel (UNF) reduce the volume, radiotoxicity, and thermal load of the radioactive waste that will be permanently stored or disposed in a geological repository. Solvent extraction separations have been the predominant technology for this purpose, but the co extraction of interfering fission products poses important scientific and technical challenges. One such interfering fission product is Zr, which is found to co extract with actinides, Pu(IV) in particular, and represents one of the major contaminants present in actinide products. The addition of aqueous complexing agents can potentially prevent the co extraction of such fission products. Specifically, CDTA, a structural analog of EDTA, has been suggested for use in the Actinide Lanthanide Separation Process (ALSEP) for Zr holdback. This work quantified the complexation of Zr(IV) with EDTA and CDTA via measurement of the Zr(IV) ligand stability constants using a solvent extraction technique. The protonation constants of EDTA and CDTA in the media of interest were also determined and Specific ion Interaction Theory parameters were derived. The measured Zr(IV) ligand stability constants were used to predict metal speciations and data were compared to similar Pu(IV) complexes. This work was funded by the U.S. Department of Energy Nuclear Energy University Program (NEUP) through grant DE NE0000674. Log 179. ACTINIDE TARGETS FOR MEASUREMENT OF THE TOTAL KINETIC ENERGY RELEASE IN FISSION. Loveland, W (1). (1) Oregon State University. The measurement of the absolute values of the total kinetic energy release (TKE) in fission requires a thin uniform deposit of the actinide material on a thin backing. The energy loss of the fragments in the target and backing material must be carefully measured. Benchmarking the TKE measurement by determining the TKE release in thermal neutron induced fission is strongly advised. Targets prepared by vapor deposition are thought to be optimal due to their uniformity (< 5% variation in thickness across the target deposit) and a well-characterized chemical composition. (Targets prepared by molecular plating suffer from unknown contaminants in the deposit due to cracking of the solvent molecules in plating and poorly characterized chemical composition.) I describe out efforts to prepare vapor deposited targets of the "easy" nuclides (233,235.238)U and 232Th) and the "harder" nuclides (237Np,239Pu) where the fluoride complexes of the actinides had to be synthesized, purified and evaporated. I compare the performance of vapor deposited and molecular plated targets of these nuclides.


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Log 180. USE OF SODIUM BISMUTHATE CHROMATOGRAPHY FOR THE ISOLATION OF AMERICIUM FROM CURIUM, LANTHANIDES, AND FISSION PRODUCT ELEMENTS. Richards, J. M. (1); Sudowe, R. (2). (1) Radiochemistry Program, University of Nevada Las Vegas. (2) Department of Environmental and Radiological Health Sciences, Colorado State University. A novel method for partitioning of americium from curium has been developed using sodium bismuthate as both an oxidant and a separation medium. Methods for the partitioning of americium from curium are often complicated and time-consuming due to the similar chemical properties of these elements. A simple method for the isolation of americium from mixtures containing curium, as well as lanthanides and other fission product elements, could allow for the development of an efficient and economically feasible nuclear fuel-reprocessing scheme that would reduce the volume and hazardous lifetime of nuclear waste and increase fuel resource sustainability. Curium, lanthanides, and rare earth elements are more strongly retained than americium on undissolved sodium bismuthate at nitric acid concentrations below 1.0 M. A separation factor of .90 was obtained in 0.1 M nitric acid. In this work, the isolation of americium from PUREX raffinate solutions utilizing sodium bismuthate chromatography is explored. Sodium bismuthate chromatography is a promising method for isolating americium from PUREX raffinate solutions in a simple and cost-effective manner. Log 181. SEPARATION OF Mn-52 FROM Cr-52 FOR USE IN POSITRON EMISSION TOMOGRAPHY. Boron-Brenner, L. P.(1); Sudowe, R.(2). (1) University of Nevada Las Vegas. (2) Colorado State University. Mn-52 is a radionuclide of interest in nuclear medicine being considered for utilization in Position Emission Tomography (PET). This isotope would be useful for PET because of its longer half-life (5.591 days) relative to other commonly used isotopes C-13, N-13, and F-18 (~20 minutes to a few hours) while having a similar positron decay energy. Mn-52 could easily be produced at a cyclotron, chemically separated, and then shipped to hospitals allowing for wider use of PET while minimizing the need to purchase cyclotrons and have chemistry laboratories for radioisotope separations. In this work, the separation of manganese-52 (Mn-52) from chromium-52 (Cr-52) was investigated using both solvent extraction and extraction chromatographic techniques. Solvent extraction was employed using trioctylamine (TOA) in cyclohexane to separate stable Mn(II) from stable Cr(III) in mineral acids. Based on the optimal separation conditions determined, several extraction chromatography resins were produced by Triskem international. These resins were characterized to determine their utility while minimizing mixed organic waste produced in the solvent extraction process. Log 182. CALCIUM AND IRON ANALYSIS OF URANINITE AND ALTERATION MINERALS: DEVELOPMENT OF POTENTIAL NEW FORENSIC ISOTOPE TRACER METHODS. Gunther, T. (1); Corcoran, L. (1); Simonetti, A. (1); Burns, P.C. (1). (1) University of Notre Dame. Employing methods that aid in tracking down illicit nuclear materials, such as uraninite (UO2) or uranium ore concentrate (UOC), are of utmost importance in forensic analyses for source attribution purposes. Natural uranium ores and UOCs are part of the early stages of the nuclear fuel cycle and constitute commonly intercepted materials. Consequently, there is a need to better understand and document the forensic signatures of different ore types such that an origin can be determined for seized illicit nuclear materials. Recently, several studies have successfully attributed uranium ores and UOCs to specific mining/geographic areas based on trace element abundances (e.g., rare earth elements-REEs) and isotopic (Sr, U) fingerprinting. Uranium ore and UOCs are also known to contain a myriad of trace elements that persist as impurities through the enrichment process, such as aluminum, calcium, potassium among others. Moreover, natural uraninite is commonly associated with secondary Ca- and Fe-rich alteration zones/phases that are characterized by variable REE contents. Hence, this investigation examines Ca and Fe isotope signatures for uraninite and its alteration products. Samples chosen exhibit varying degrees of alteration so as to expand our understanding of conditions (temperature, redox conditions) present during alteration and possible effects on Ca and Fe isotopic ratios, and represent four different uranium ore deposit types (Intrusive, Sandstone, Unconformity and Vein Type – Granite). Fe and Ca concentrations vary substantially with virtually negligible abundances for pristine uraninites to above 50 wt% for some altered regions that consist of various U-bearing secondary minerals.


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Log 183. THE FACILE PRODUCTION OF Ar-37 USING A THERMAL NEUTRON REACTOR FLUX. Kelly, D.G. (1); Corcoran, E.C. (1); Dunford, D. (2); Gerbier, G. (2); Faurschou, A. (2); McDonald, J.M. (2); Mumby, T. (1); Samuleev, P. (1). (1) Royal Military College of Canada. (2) Queen's University. The News-G project will conduct dark matter detection experiments using instrumentation located underground at the Sudbury Neutron Laboratory (SNOLab). Detection occurs with a low pressure copper sphere, partially filled with noble gases quenched with methane. Ar-37 decays by electron capture with a half-life of 35.1 d, providing low energy X-rays (2.8 and 0.27 keV). This radionuclide provides an ideal gaseous calibration source. However, the timing and location of this work require a facile method of Ar-37 production which provides Ar-37 in the absence of contaminating sample or container radionuclides. This outcome has been achieved by the irradiation of CaO using the thermal flux of a SLOWPOKE-2 nuclear reactor. Ca-41 (Ca-40 + n -> Ca-41 -> Ar-37 + alpha). It has been demonstrated that nano CaO affords significantly higher Ar-37 yields than CaO of micron dimensions, a feature that is presumed to result from greater Ar-37 liberation during alpha decay recoil. Irradiation vessel design has allowed the use of high vacuum vessel of low neutron cross-section within the confined geometry of the SLOWPOKE-2 irradiation sites. Subsequent diffusion in vacuo to an unirradiated transfer container has proved sufficient to afford gaseous Ar-37 in high yield. Ar-37 production has been successfully modeled in MCNP based on a model of SLOWPOKE-2 neutron flux. Log 184. ACTINIDE DETERMINATION IN BONE SAMPLE - EFFECT OF MATRIX CONSTITUENTS. Nguyen, N.T. (1); Sudowe, R. (1). (1) Colorado State University. There are numerous methods available in the literature for separating and analyzing radionuclides of interest from an array of environmental matrices. The quality of these methods is however impeded by the elemental constituents that are commonly found in many of these samples. The presence of interfering constituents can result in incomplete separation of the radioisotopes of interest as well as a reduced rate of recovery. This is especially the case when analyzing complex matrices such as samples of bone and bone ash. Alpha-emitting isotopes of plutonium and americium are bone seekers. This means they have an affinity to accumulate in actively metabolizing portions of bones of many mammals including humans. It is therefore extremely important to study and evaluate the uptake of these radionuclides in human bone samples. Nevertheless, in agreement with literature, high concentrations of calcium present in the hydroxyapatite that constitutes the bone as well as sodium and potassium also present have the potential to strongly affect radiochemical separation methods. The objective of this research is to investigate the influence of the major and minor constituents present in bone on the radioanalytical determination of plutonium and americium using extraction chromatographic resins.


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Log 185. TRACING THE SOURCES AND DYNAMICS OF CONTAMINATED SEDIMENT IN COASTAL RIVERS DRAINING THE MAIN FUKUSHIMA RADIOACTIVE FALLOUT PLUME USING GAMMA-EMITTING RADIONUCLIDES AND CARBON/NITROGEN STABLE ISOTOPES (2011-2017). Evrard, O. (1); Laceby, J.P. (1,2); Onda, Y. (3); Hayashi, S. (4); Tsuji, H. (4); Huon, S. (5); Lefèvre, I. (1); Jaegler, H. (1); Landemaine, V. (6); Vandromme, R. (6); Cerdan, O. (6). (1) Laboratoire des Sciences du Climat et de l’Environnement (LSCE, joint laboratory CEA/CNRS/UVSQ), France. (2) Environmental Monitoring and Science Division, Alberta Environment and Parks, Canada. (3) Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Japan. (4) National Institute for Environmental Science, Fukushima Branch, Miharu, Japan. (5) Sorbonne Universités, UPMC, Institut d'Ecologie et des Sciences de l'Environnement de Paris (iEES), France. (6) BRGM, France. Fieldwork was conducted every 6 months between 2011 and 2017 to monitor the dispersion of sediment contaminated with radionuclides in rivers draining the main Fukushima radioactive pollution plume (~500 km.). Fine sediment was systematically collected at the same locations (n=47) and analysed for gamma-emitting radionuclides (including 137Cs and 110mAg). A selection of samples was also analysed for carbon/nitrogen concentrations and isotopes. Organic matter analyses showed that paddy fields provided the main source of contaminated sediment to the rivers shortly after the accident. The spatial variations of the 110mAg:137Cs activity ratio in soils were used to demonstrate the very rapid export of sediment to the Pacific Ocean. However, this tool could only be used during the first campaigns, because of the quick decay of 110mAg. Overall, radiocesium concentrations measured in sediment deposits decreased by ~90% between 2011 and 2017. This may be explained by remediation works, by a massive export of material during typhoons and by the occurrence of landslides or channel bank erosion that supply material sheltered from the Fukushima fallout to the river network. Consequently, 6 years after the accident, most of the residual radioactive contamination is found in forests and in dam reservoirs. The analysis of sediment cores collected in a reservoir confirmed the significant storage of contaminated material in these lakes and that paddy fields provided their main source. Ongoing research focuses on the development of a soil erosion model and on the quantification of the impact of remediation works. Log 186. NEW ANALYTICAL CAPABILITIES WITH MICROCALORIMETERS. Croce, M. (1); Koehler, K. (1); Hoover, A. (1); Mocko, V. (1); Kozimor, S. (1) Rabin, M. (1); McIntosh, K. (1); Havrilla, G. (1); Bennett, (2); Mates, J. (2); Gard, J. (2); Schmidt, D. (2); Ullom, J. (2); Carpenter, M. (3); Cantor, R. (1) Los Alamos National Laboratory. (2) National Institute of Standards and Technology, Boulder. (3) STAR Cryoelectronics. The capabilities of low-temperature microcalorimeters are enabling new possibilities in nuclear material analysis. We present our recent work to develop superconducting transition-edge sensor microcalorimeters and analytical techniques for decay energy, x-ray, and gamma-ray spectroscopy of nuclear materials. Decay energy spectroscopy, in which a radioactive sample is embedded within a microcalorimeter absorber, is an emerging technique for determining the isotopic composition of trace-level samples. For each alpha-decaying nuclide, a single peak at its unique total nuclear decay energy (Q value) is measured. For beta-decaying nuclides, where the neutrino or antineutrino will escape the absorber, a continuous spectrum ending at the Q value is measured. We are developing sensors and methods to enable decay energy spectroscopy of a broad range of samples from pure certified reference materials to nuclear detonation debris. We have demonstrated that microcalorimeter x-ray emission spectroscopy has the resolution to measure subtle effects of chemical bonding and nondestructively determine chemical speciation in nuclear materials, and are now evaluating potential applications. Measurements over the past several years with a time-division multiplexed 256-pixel microcalorimeter gamma ray spectrometer have demonstrated the advantages of improved energy resolution over high-purity germanium detectors. The order-of-magnitude improvement in energy resolution enables more precise and accurate nondestructive measurement of plutonium isotopic composition, an important goal for nuclear safeguards. High-bandwidth microwave frequency-division multiplexing will soon enable high-throughput microcalorimeter gamma spectrometers suitable for deployment in operational nuclear facilities. We discuss the latest developments in these three analytical techniques, and present recent results.


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Log 188. AN ONLINE SPECTRA ANALYSIS SYSTEM FOR INSTRUMENTAL NUCLEAR ACTIVATION ANALYSIS. Sun, Z.J. (1); Cai, Q.S. (2). (1) Nuclear Engineering Program, South Carolina State University. (2) Nuclear Reactor Program, North Carolina State University. Instrumental Neutron Activation Analysis requires extensive data analysis. The calculation process is tedious and susceptible to error. For saving time, reducing manpower, and minimizing human error, a web-based computer program Nuclear Activation Analysis System (NAAS) is designed, built and implemented by C#, SQL and asp.net technology at the Applied Radiation Science Laboratory (ARSL) to automate this process. Based on the peak information of the spectra, the program automatically identifies elements in the samples and calculates their concentrations with the assistance of the supporting NAA library. Results from this software are compared with standard INAA calculations with excellent consistency. With minimum input from the user, the software has proven to be fast and reliable. The program is particularly user-friendly for these colleagues (e.g. archaeologists, biologists, environmentalist, geologists, etc.) who are interested in nuclear activation analysis, but not knowledgeable about the underneath details of the nuclear reactions as well as the corresponding activation calculations. Log 189. DETERMINING TOXIC ELEMENTS IN COTTON SEEDS WITH INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS (INAA). Sun, Z.J. (1); Isa, N. (1); Nwosu, E. (1); Jordan, K. (1); Nelson, G. (1); Cai, Q.S. (2); Lassell, S. (2). (1) Nuclear Engineering Program, South Carolina State University. (2) Nuclear Reactor Program, North Carolina State University. Cotton has been a major cash crop in South Carolina since revolutionary times to current day. Throughout the growing season, cotton assimilates numerous trace elements from the soil, including the toxic ones. Some of these trace elements are accumulated and enriched in cotton seeds. Therefore, cotton seeds can serve as a biological indicator of heavy metal contamination in local soil. Like other states, South Carolina is subject to the environmental impact of human behaviors. Dozens of heavily-polluted superfund sites are scattered in the state, and some of them are close to cotton plantations. It is conceivable that cotton may be under contamination impact of these sites through ground water movement or other migration paths. In this study, several cotton seeds and corresponding local soil samples from the Midlands Region of South Carolina were studied by instrumental neutron activation analysis (INAA). After irradiation of the samples with thermal and epithermal neutrons from the PULSTAR Reactor, all of short-lived, medium-lived and long-lived isotopes spectra were collected with HPGe spectrometers. The pilot study indicated that: (1) INAA is a competent tool for conducting multi-element analysis in agricultural products, especially cash crops. It is capable to determine the level of elements in soil and cotton seeds with high accuracy and extreme sensitivity. (2) cotton, as a life form, works like a refining factory which has the ability to not only increase the concentration of essential elements in seeds but also block some elements which it does not need.


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Log 191. DEVELOPMENT OF SEQUENTIAL Pu-Np-Am CHEMICAL SEPARATIONS AND MULTIPLE ION COUNTING ICPMS FOR Pu-241/Am-241 DATING OF ENVIRONMENTAL SAMPLES ON A SINGLE ALIQUOT. Goldstein, S.J. (1); Hinrichs, K.A. (1); Nunn, A.J. (1);, Gurganus, D.W. (1); Amato, R.S. (1); Oldham, W.J. (1). (1) Nuclear and Radiochemistry Group, Los Alamos National Laboratory. In 241Pu-241Am dating of environmental samples by mass spectrometry, it is desirable to measure Pu and Am on a single aliquot to maximize sample utilization and decrease analyses times. This requires sequential chemical separations of Pu-Np and Am followed by isotopic analyses by thermal ionization (TIMS) or inductively coupled plasma (ICPMS) mass spectrometry. We have a long-established method for measurement of long-lived Pu-Np isotopes together in environmental samples by resin bead multiple ion counting (MIC) TIMS. Chemical separations for this method include two co-precipitations with neodymium and iron carriers, followed by two nitric acid anion columns for Pu-Np purification. A major issue is separation of Am from the Nd carrier. We found that Am-Nd separation factors for a thiocyanate-TEVA column are ~250,000, above the needed threshold of 5000 (10 ug Nd). Hence, our Am separation method adds only one HCl-anion column for Fe separation followed by the thiocyanate-TEVA column with chemical yields ~80-90% for Pu, Np, and Am. The MIC-ICPMS method for Am uses a Nu Plasma-II mass spectrometer with 5 ion counters. Am ion yields on most samples and standards are ~0.6%. We have tested our sequential MIC-ICPMS method for accuracy and precision using gram quantities of two certified reference materials, IAEA-385 (Irish Sea sediment) and NIST-4350B (Columbia River sediment). Preliminary 241Am concentrations of 7.52E7 and 3.25E6 atoms/g are biased by –0.6% and +9.0% respectively relative to their certified values but are within measurement and certification errors. Their respective Pu-Am single-component model calendar ages are 1964 and 1954. Log 192. FUKUSHIMA-DERIVED RADIOCESIUM FALLOUT MAP OF HAWAII. McKenzie, T. (1); Dulai, H. (1). (1) University of Hawaii at Manoa, Department of Geology & Geophysics. Reactors at the Fukushima Dai-ichi Nuclear Power Plant suffered damage in March 2011, resulting in the release of radiocesium (134Cs and 137Cs) into the atmosphere. A week later, Fukushima-derived cesium was detected in aerosols over the state of Hawai.i as well as in milk samples analyzed from the island of Hawai.i. This study estimated the magnitude of cesium deposition and examined its trends against precipitation patterns, in addition to its distribution with respect to land use in Hawai.i. Fukushima-derived fallout was differentiated from historic nuclear weapons testing fallout by the presence of 134Cs. Detectable, Fukushima-derived 134Cs inventories ranged from 30 to 630 Bq/m² and 137Cs inventories ranged from 20 to 2200 Bq/m². Fukushima-derived cesium inventories in soils were related to precipitation gradients, particularly in areas where rainfall exceeded 200 mm between March 19 and April 4, 2011. Maps of cesium fallout were created by interpolation of field data between precipitation gradients, and extrapolation where field data were unattainable. This study not only confirmed the presence of Fukushima-derived fallout in Hawai.i, but also found it in concentrations higher than predicted by atmospheric models and observed in the United States mainland. The activities detected, however, were an order of magnitude lower than fallout associated with historic sources such as the nuclear weapons testing in the Pacific. In addition, this study showed that areas of highest cesium deposition do not coincide with densely populated or areas used for agriculture.


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Log 193. COMPARISON OF THE DAVIES AND GRAY TITRIMETRIC METHOD WITH POTASSIUM DICHROMATE AND CERIC TITRANTS. Wylie, E.M. (1); Coletti, L. (1); Walker, L. (1); Lujan, E. (1); Garduno, K. (1); Mathew, K. (1). (1) Actinide Analytical Chemistry, Los Alamos National Laboratory. The Davies & Gray titrimetry method can be used for uranium content measurements on a variety of uranium bulk materials (metals, alloys, oxides, mixed oxides, and solutions). In the modified NBL Davies & Gray tirimetry method, potassium dichromate standard 136f from NIST is used for calibration; however, the presence of chromium in the resulting waste stream makes the disposal of the waste from this procedure costly. The Actinide Analytical Chemistry (C-AAC) group at Los Alamos National Laboratory (LANL) investigated and transitioned to a cerium based titrant as an alternative. The precision, accuracy, and overall uncertainties achievable with this ceric based titrimetry method are comparable to that based on potassium dichromate as a titrant. We present analytical data using this ceric based titration method and compare it with that from NBL based on the more-widely used dichromate titrimetric method. For both ceric and dichromate based titrations, systematic biases due to presence of impurities are at similar levels. NBL natural uranium metal standard CRM 112-A is often used as a calibration standard for the ceric titrimetry method and to provide traceability of the analytical results to S.I. units. LANL also utilizes an exchange standard that is analyzed independently by several external laboratories. Standard reference material (SRM) 950b is used as another check standard for cerium based titrimetry. In terms of accuracy and precision, both dichromate and ceric based titrations perform at levels that meet or exceed the 2010 international Log 194. DETERMINATION OF GEOLOGICAL HOST PHASE OF SOIL CONTAMINATES IN THE FUKUSHIMA EXCLUSION ZONE USING SEQUENTIAL EXTRACTION TECHNIQUES. McNabb, I.M. (1); Sudowe R. (1). (1) Colorado State University. The nuclear reactor accident at the Fukushima Daiichi power plant resulted in the release of large quantities of various radionuclides into the environment. The surroundings of the Fukushima nuclear power plant provide therefore an involuntary, but nonetheless unique opportunity to investigate the behavior of elements such as plutonium and cesium in an eco-system. Several areas in the vicinity of the power plant are still considered an exclusion zone and have not been cleared for human resettlement. While these areas are not suitable for permanent habitation, they are accessible for field work. The purpose of this research is to analyze the movement and bioavailability of radiocesium and plutonium in the ecosystems contaminated by the Fukushima Daiichi nuclear reactor accident. This will be done by collecting and analyzing soil, sediment, water, and vegetation samples from within the inclusion zone. Most of the existing studies have focused on determining the total amount of cesium and plutonium in soil. While this provides important data on the distribution of these radionuclides in the environment, it yields limited information on the bioavailability of these elements. Therefore, in this work the samples will be analyzed using sequential extraction techniques. By treating the samples with increasingly aggressive chemicals, it is possible to discover the geological host phase to which the radionuclides are bound. In addition to further the overall understanding of cesium and plutonium transport pathways in natural ecosystems, this research will also provide an opportunity to validate the sequential extraction procedures developed using real-world samples.


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Log 195. SELECTIVE EXTRACTION AND SUB-PICOGRAM QUANTIFICATION OF DISSOLVE GASSEOUS MERCURY IN CAUSTIC NUCLEAR TANK WASTE. Boggess, A.J. (1); Jones, M.A. (1); Bannochie, C.J. (2); Ekechukwu, A.A. (1); Wilmarth, W.R. (3); White, T.L. (1). (1) Savannah River National Laboratory - Analytical Development. (2) Savannah River National Laboratory - Materials Processing Technology. (3) Savannah River National Laboratory - Chemical Processing Technology. Savannah River Site (SRS), operated by the U.S. Department of Energy (DOE), houses two nuclear waste tank storage farms for high-level legacy waste. Ongoing remediation and treatment processes have utilized elemental mercury to aid in catalytic dissolution of aluminum cladding from enriched-alloy uranium rods. The use of elemental mercury has resulted in deposition of over 65,000 kg of mercury in the SRS tank farms, with no existing analytical methods available to monitor for specific mercury species over time in this sample-type. This work describes research performed to develop, optimize, and externally validate via interlaboratory comparison an analytical method to selectively extract and quantify dissolved gaseous mercury in highly caustic nuclear tank waste. Unique techniques for introducing matrix spikes were developed and high sensitivity was ultimately achieved, with a method detection limit of <1 pg. A sensitive and safe method has been developed to selectively extract dissolved gaseous mercury from caustic nuclear tank waste and has been validated by interlaboratory comparison, while conforming to the unique safety and security framework of a radioanalytical facility. Log 196. SEASONAL AND LOCATIONAL VARIATIONS OF SELECTED TRACE ELEMENT LEVELS MEASURED BY NEUTRON ACTIVATION IN BIOACCESSIBLE FRACTIONS OF HEPATOPANCREAS AND GILLS OF JAPANESE CULTIVATED OYSTERS. Fukushima, M. (1); Chatt, A. (2). (1) Department of Food and Environment, Ishinomaki Senshu University, Japan. (2) Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Canada. Japanese cultivated oysters were collected from six different locations in Ishinomaki Bay in 2015 May. To study any possible seasonal variation, oyster samples were also collected every month from April to September from one of these cultivation areas. Soft tissues were separated from shells of 5 oysters, washed with tap water, separated into gills, mantles, muscles, and hepatopancreas. Each organ was freeze dried, pulverized, and irradiated for 1 h at a neutron flux of 3 x 1013 cm-2 s-1 in the Kyoto University Reactor, Japan. Gamma-ray spectra of the irradiated samples were recorded after one-month decay for 20-30 min using a Ge detector system. Levels of Ag, Co, Cr, Fe, Mn, Rb, Sc, Se, and Zn were obtained using 110mAg, 60Co, 51Cr, 59Fe, 54Mn, 86Rb, 46Sc, 75Se, and 65Zn, respectively. The instrumental neutron activation analysis (INAA) method used was validated using NIST 1566b Oyster Tissue and NRCC TORT-1 Lobster Hepatopancreas certified reference materials. Bioaccessible trace element levels in soft tissues of oysters were also estimated by using an AOAC method. Briefly, about 1 g of dried oyster soft tissue powders was incubated with .-amylase, protease, and amyloglucosidase one after another. Water soluble dietary fiber was filtered from the undigested residue after adding ethanol, and both fractions were analyzed by INAA. In general, no significant changes in levels of trace elements were found from one area to another. However, seasonal variations in the levels of selected trace elements in hepatopancreas and gill from one area were observed.


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Log 197. INTERNATIONAL EXPERIMENTAL ROUND ROBIN OF SAMARIUM-153. Jackson, M. J. (1); Gilligan, C. (1); Davies, A. V. (1); Britton, R. (1); Friese, J. (2); Greenwood, L. (2); Pierson, B. (2); Dry, D. (3); May, I. (3); Smythe, N. C. (3); Gaunt, A. J. (3); Thomas, E. (3); Roberts, K. (4). (1) Atomic Weapons Establishment, UK. (2) Pacific Northwest National Laboratory, USA. (3) Los Alamos National Laboratory, USA. (4) Lawrence Livermore National Laboratory, USA. Samarium-153 is one of the many isotopes of interest to the post-detonation nuclear forensics community. This short-lived radionuclide decays to stable Europium-153 via beta emission, with subsequent de-excitation via gamma emission and internal conversion (X-ray emission). Historical measurements of Samarium-153 by gamma emission and beta liquid scintillation counting have shown a low bias compared to beta proportional counting. In order to investigate this, four national laboratories jointly conducted an experimental round robin on a certified Samarium-153 sample, created from neutron activation of Samarium-152 and obtained from the UK National Physical Laboratory. Radiometric measurements were conducted using gamma spectroscopy, liquid scintillation, gas proportional counting and passivated implanted planar silicon detectors and compared across all four institutions. Results from this international experiment are presented together with the conclusions of the experiment, which suggest that the current published cumulative fission yield for Samarium-153 is approximately 15% high and is the likely cause of the previously observed historical bias. Log 198. UTILISATION OF CARBON DIOXIDE AS A REACTION CELL GAS IN INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ICP-MS) FOR THE RAPID ANALYSIS OF URANIUM AND PLUTNIUM FOR NUCLEAR FORENSIC APPLICATIONS. Childs, D.A. (1); Hill, J.G. (1). (1) AWE. A method was developed for the in-situ separation and subsequent trace analysis of uranium and plutonium using carbon dioxide as the reaction cell gas when using quadrupole ICP-MS. This instrumental separation was required in order to remove isobaric and polyatomic ion interferences. Development of the method was required to assist in the rapid screening of nuclear forensic samples by providing quantification of uranium and plutonium and the determination of isotope ratios. This method provides an alternative to chemical separation techniques currently used, reducing sample analysis time and the potential for contamination. It was shown that by increasing the flow rate of carbon dioxide gas into the reaction cell, the uranium and uranium hydride signals decreases much more readily than that of plutonium. This reduction in signal was shown to be due to an oxidation reaction that occurs at a greater rate with uranium than plutonium.[1][2] With optimisation of instrument tuning parameters and carbon dioxide gas flow rate, it was possible to quantify plutonium whilst removing all interfering uranium species. It was also shown that measurement of the uranium double oxide ion formed in the reaction cell was the most effective product ion for the quantification of uranium and determination of uranium isotope ratios. Further to this, feasibility studies were conducted to determine if this method could be used as a screening technique for quantifying both uranium and plutonium as well as determining isotope ratios in a range of complex sample matrices.


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Log 199. RIMMER: A MONTE-CARLO BASED NUCLEAR DECAY SCHEME TOOLKIT FOR TRUE-COINCIDENCE SUMMING CORRECTIONS AND GAMMA-GAMMA COINCIDENCE APPLICATIONS. Jackson, M. J. (1); Britton, R. (1); Davies, A. V. (1). (1) Atomic Weapons Establishment, UK. A strong understanding of the physics of nuclear decay is a vital part of any radiometric measurement practice. At a basic level, this includes emission energies and probabilities for a given nuclide. At a deeper level, one requires a more detailed understanding of decay cascades and their respective probabilities in order to improve activity quantification practices or even quantify at all. In single detector applications, the effects of true-coincidence summing must be evaluated to ensure accurate reporting of nuclide activities. In advanced radiometric techniques such as gamma-gamma coincidence, a strong understanding of the nuclide decay scheme and the probability of individual decay cascades is fundamental to any activity quantification procedure. To support each of these areas, a Monte-Carlo based toolkit has been developed to improve the accuracy of quantitative reporting in any radiometric-based field, including Nuclear Forensics, treaty verification and environmental monitoring. This novel tool combines a detector efficiency characterisation with nuclear decay data to provide an expandable suite of correction factors for any number of nuclides and counting systems. RIMMER currently includes support for beta-, beta+ and electron capture decays and accounts for gamma, X-ray, electron and annihilation radiation emissions. In single detector applications, RIMMER is used to calculate true-coincidence summing correction factors for every emission line for a given nuclide and has been demonstrated to exceed the functionality of many industry standard equivalents. In multi-detector coincidence applications, RIMMER can be used to quantify radionuclides based on specific coincidence signatures, alleviating emission interferences and enabling extraction of low-yield signatures. Log 200. A GAMMA-GAMMA COINCIDENCE MEASUREMENT SYSTEM FOR NUCLEAR FORENSICS APPLICATIONS. Jackson, M. J. (1); Davies, A. V. (1); Britton, R. (1). (1) Atomic Weapons Establishment, UK. Radiometric analysis of high-activity samples arising from post-detonation Nuclear Forensic is often complicated by a large number of emission peaks, line interferences and poor signal-to-noise ratio for low fission yield isotopes. Traditionally, radiochemical separations have been used to address these complications and simplify the subsequent analysis. While these methods can be successful in their objective, such practices are not always reliable and can take considerable time to complete. They are also destructive in their nature and can increase the final uncertainty estimate when chemical yielding. Several of the isotopes of interest to post-detonation nuclear forensics are cascade gamma emitters, radiating multiple gamma and / or X-rays with each decay. This phenomenon can be exploited using a multi-detector based system used to search for gamma-gamma and / or gamma-X-ray coincidence signatures. These near-unique signatures can be used to address some of the complications without the need for separation chemistry. Two systems have been developed to fulfil this role for laboratory and in-field operations, and simultaneously record singles, summed-singles and coincidence data for each acquisition. When coupled with RIMMER - a Monte-Carlo based nuclear decay scheme toolkit developed at AWE - these time-synchronised radiation detection systems can be used to both identify and quantify radionuclides using coincidence signatures. Combining multiple measurement practices into a single acquisition allows for the inclusion of both cascade and non-cascade emitting radionuclides and can improve the overall confidence in radionuclide identification and quantification with agreement between the three methods.


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Log 201. RADIOLYTIC DEGRADATION OF HYDROPHILIC DIGLYCOLAMIDES. Wilden, A. (1); Mincher, B.J. (2); Mezyk, S.P. (3); Rosciolo-Johnson, K.M. (2); Zarzana, C.A. (2); Case, M.E.A. (2); Modolo, G. (1). (1) Forschungszentrum Juelich GmbH, Germany. (2) Idaho National Laboratory. (3) California State University at Long Beach. Diglycolamides (DGAs) are widely used in separation processes for the separation of trivalent actinides (An(III)) and lanthanides (Ln(III)) with regards to used nuclear fuel partitioning. The lipophilic DGAs are commonly used as extractants, with TODGA (tetra-octyl DGA) being the most prominent member. Recently, the hydrophilic DGAs received increased attention, as they are used for the complexation of metal ions in aqueous phase, e.g. in the French EXAm process. Therefore, the stability of different hydrophilic DGAs against radiolysis was studied. The hydrophilic DGAs TMDGA, TEDGA, Me-TEDGA, and Me2-TEDGA were gamma irradiated in aqueous solution up to 150 kGy. Ligand concentrations after radiolysis and radiolysis products were determined by HPLC-MS methods including high resolution MS. An exponential decrease with increasing dose was observed, suggesting pseudo first-order kinetic. The dose constants were determined and were found to be ca. twice that reported for lipophilic DGAs. Radiolysis products were identified and showed to be partly comparable to those found for lipophilic DGAs. However, some deviations were also observed, which are explained by the different nature of the diluent, i.e. water against dodecane. The role of the diluent will be discussed and the radiolysis of hydrophilic and lipophilic DGAs will be compared. Furthermore, the role of radical formation from the diluent will be discussed in view of a mechanistic understanding of the radiolysis of DGAs. Log 202. EFFICIENT REMOVAL OF RADIONUCLIDES FROM AQUEOUS SOLUTIONS USING CARBON NANOMATERIALS. Wang, X. (1). (1) North China Electric Power University. This page presents the surface modification of carbon nanomaterials (carbon nanotubes, graphene oxides) using different functional groups and their application for the efficient and selective elimination of radionuclides from aqueous solutions. The interaction mechanism between radionuclides and carbon nanomaterials was studied by batch sorption experiments, surface complexation modeling, spectroscopy analysis (XPS and EXAFS) and theoretical calculations. The results showed that the carbon nanomaterials have high sorption capacity in the preconcentration of radionuclides from large volume of aqueous solutions, and the surface grafting functional groups could enhance the selectivity of radionulcides from solutions. The interaction of Eu(III), Am(III) and U(VI) with graphene oxides and carbon nanotubes were studied under different experimental conditions, and the difference in the interaction of trivalent lanthanides and actinides were found quite different under same experimental conditions, which were quite different from the physicochemical behaviors of lanthanides and actinides on clay minerals and oxides. The difference was attributed to the surface properties of nanomaterials and the radionuclides.


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Log 203. BIOGENIC GOLD NANOPARTICLES FOR THE EFFICIENT REMOVAL OF RADIOACTIVE IODINE. Choi, Y.J. (1); Jeong, S.-W.(1); Kang, C.G.(1); Lee, S.H.(1). (1) University of Seoul. The huge amount of radioactive wastes generated from industries such as nuclear power plants and hospital were leaked into environment and resulted in extensive contamination of the atmosphere, ground- and seawater. Thus, increasing concerns on the radioactive substances have been drawn much attention on the development of remediation strategy. Radioactive iodine is one of the most hazardous elements contained in the radioactive wastes. Recently, cost-effective and eco-friendly bioremediation strategy using microorganism have been suggested to remove the radioactive wastes. The radioresistant bacterium Deinococcus radiodurans is the best known for its resistance to radiation, oxidants, and desiccation. Because of its remarkable radioresistant capacity, this bacterium makes it an ideal candidate for bioremediation of radioactive wastes. In this study, we reported a new bioremediation technology for removal of radioactive iodine using D. radiodurans. Biogenic gold nanoparticles embedded in D. radiodurans showed an excellent removal capability of reactive iodine (> 99%) in several aqueous solutions. From these results, our remediation technology would be applied to the treatment of radioactive wastes. Log 204. DEVELOPMENT OF ENGINEERED NANOCOMPOSITE MEMBRANES FOR SELECTIVE DESALINATION OF RADIOACTIVE IODINE IN AQUEOUS MEDIA. Jeon, J. (1,2); Mushtaq, S. (1,2); Shim, H.E.(1). (1) Korea Atomic Energy Research Institute. (2) University of Science and Technology. Efficient treatment of radioactive wastes caused by overuse of radioisotopes and nuclear reactor accidents has become an important environmental issue, and much effort has been made to removal of toxic radioactive materials. Among them, aqueous radioactive iodine waste is recognized as one of the most serious threats to environment and humans, because it is generated by large number of medical institutes and industrial applications. Although a few adsorbents and processes have been reported, the development of a better desalination method which is able to provide high desalination efficiency, ion-specificity, and sustainability is still in demand. We herein demonstrate a hybrid membrane, composed of gold nanomaterials and cellulose acetate membranes, which has the potential to be applied to efficient separation of radioactive iodine. A single filtration step using this hybrid membrane showed excellent ion-selectivity and high removal efficiency (>99%, within 1 minute) of radioactive iodine in seawater and synthetic urine. In addition, the same operation can be applied several times without significant decrease of its desalination efficiency. Therefore, the nanocomposite membranes and methods in this work will be a new avenue for desalination of radioactive iodine in various aqueous media.


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Log 205. THREE-DIMENSIONAL VISUALIZATION OF GROWTH AND MORPHOLOGY OF CERIUM ELECTRODEPOSIT RECOVERED FROM HIGH TEMPERATURE MOLTEN LiCl-KCl BY RADIOGRAPHY. Jee, Y.T. (1); Park, M. (1); Cho, S. (1); Yun, J.-I. (1). (1) KAIST. The growth of dendritic solid metal in pyroprocessing drastically enlarges a surface area of the working electrode and thus causes an entire transition of electrochemical condition. However, the morphological analysis on electrodeposits is hardly carried out due to attached or trapped LiCl-KCl salts in the metal structure. This work proposes a utilization of radiography to selectively acquire a structural image of cerium metal excluding that of LiCl-KCl. Different mass attenuation coefficients of metal and salt enable the distinction of two structures. A histogram with a number of counts for different brightness shows two conspicuous peaks: metal at the dark side and salt at the bright side. Based on this approach, it is verified that the electrodeposit forms a mossy structure along the electrode in galvanostatic electrodeposition, providing a gradual decrease in the current density. On the other hand, in potentiostatic electrodeposition, the structure of electrodeposit is varied at diverse concentrations which yields a different magnitude of the current flow. At low concentration, the electrodeposit displays a mossy structure similar to that for the galvanostatic case, and at high concentration, the electrodeposit forms a well-spread cloudy structure with a large amount of LiCl-KCl trapped inside. Moreover, throughout the electrodepositions in a different time scale, it is clearly visualized that the galvanostatic electrodeposit grows along the electrode at once, while the potentiostatic electrodeposit grows from the top part of immersed electrode: the surface of the molten medium. In conclusion, radiography provides tremendous benefits for the clarification of electrodeposition under different electrochemical conditions. Log 206. CAPABILITIES AND LIMITATIONS OF IN-SEM RAMAN ANALYSIS FOR IDENTIFICATION OF URANIUM CHEMICAL PHASES IN MICROMETRIC PARTICLES FOR NUCLEAR SAFEGUARDS. Pointurier, F. (1); Marie, O. (1). (1) CEA, DAM, DIF, France. Thanks to its ability to carry out structural identification of small-size objects, Micro-Raman spectrometry (MRS) is a potentially interesting tool for nuclear safeguards, as this technique allows fast and non-destructive determination of the chemical phases (i.e., stoichiometric chemical composition and possibly crystallographic structure) of the main uranium compounds encountered in the nuclear industry. Analysis by stand-alone MRS can be carried out on particles of 1-2 um in diameter. However, analysis of uranium particles mixed with environmental dust requires beforehand localization of U particles by SEM, sample transfer to the MRS, and then re-localization of U particles within the. To avoid this tedious procedure, our MRS ( In Via , Renishaw, UK) was coupled to a scanning electron microscope (SEM, FEI XL-30) by means of a coupling device (“SEM–SCA”, Renishaw, UK). This interface was designed to obtain topographical information (by SEM imaging), elemental composition (by EDX spectroscopy), and chemical phases identification (by MRS) from the same spot without sample transfer. Several applications to samples relevant to nuclear safeguards will be presented. Results will be discussed with a few to show performance, capabilities and limitations of this SEM – Raman spectrometer coupling device.


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Log 207. A NON-DESTRUCTIVE ANALYTICAL TECHNIQUE FOR LOW LEVEL DETECTION OF PRASEODYMIUM USING NEUTRON ACTIVATION ANALYSIS AND COMPTON SUPPRESSION GAMMA-RAY SPECTROSCOPY. Stokley, M.B. (1, 2); Landsberger, S. (1). (1) University of Texas at Austin. (2) U.S. Army. Neutron Activation Analysis (NAA) is a non-destructive nuclear analytical method used to detect trace elemental and isotopic compositions with minimal sample preparation cost. It has proved to be accurate and at times favorable to traditional destructive trace elemental analysis techniques or those associated with extensive sample preparation requirements. However, when NAA is used to analyze samples containing numerous elements, an issue can arise in which certain isotopes produce peaks and Compton plateaus that ultimately overshadow the peaks of interest. This is the case when analyzing geological samples for trace concentrations of the rare earth metal praseodymium. Adding to the difficulty, praseodymium has only one naturally occurring isotope, Pr-141. When activated to Pr-142, only a single 1575.6 keV gamma ray is emitted. The praseodymium peak in geological samples typically sits between substantial peaks of La-140 and K-42. This peak then becomes concealed by the substantial Compton plateau of Na-24. This makes detecting trace amounts of Pr-141 (< 25 ppm) impossible using normal gamma-ray spectroscopy. A technique using a 5-10 minute epithermal neutron irradiation and Compton suppressed gamma-ray spectroscopy has allowed for Pr-141 trace elemental detection. Preliminary results using this method have shown 6 ppm in the minimum detectable concentration. Further research is being conducted to examine various irradiation, decay, and sample count times in order to establish baseline criteria for yielding optimal results. Log 208. FIELD-BASED URANIUM ISOTOPICS: MADE FAST AND EASY BY ATOMIC BEAM LASER ABSORPTION SPECTROMETRY. Bartlett, J. H. (1); Lebedev, V. (1); Castro, A. (1). (1) Los Alamos National Laboratory. Recently, we have reported on the development of a fieldable atomic beam source designed for laser absorption spectrometry. The key component of this source is a thermally-efficient resistively heated micro-crucible capable of reaching temperatures exceeding 2300 C while requiring less than 500 W of electrical power. This type of crucible, and the atomic beams that it generates, has been demonstrated and characterized using Er and U metal sources using a continuous wave external-cavity diode laser (ECDL) as the absorption reference. The atomic beam allows us to record sub-Doppler spectra with the intrinsically narrow ECDL, with typical resolution on the order of <1 GHz, capable of resolving isotope shifts for many optical transitions of the actinides. Furthermore, we have identified a 'chemistry-free' method that enables this atomic absorption method to be compatible with U compounds, to the extent that atomic U spectra have been recorded from UO2, U3O8, and UO2(NO3)2 precursors on our apparatus. U sources of various known levels of enrichment have been analyzed using this technique such that the 235/238 ratio of a sample can be determined by recording the atomic absorption spectrum. Based on these results, we are in the process of designing a prototype instrument to be field-deployable in order to perform rapid isotopic characterization of unknown U samples.


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Log 209. NEUTRON ACTIVATION OF NIST SURROGATE POST-DETONATION URBAN DEBRIS (SPUD) SRMS. Biegalski, S. (1); Kane, N. (1); Mann, J. (2); Tipping, T. (3); Dayman, K. (4). (1) Georgia Institute of Technology. (2) National Institute of Technology, Gaithersburg. (3) The University of Texas at Austin,. (4) Oak Ridge National Laboratory. Despite their importance, there is a dearth of post-detonation nuclear forensics Standard Reference Materials (SRMs) suitable for analysis traceable back to a national standard. Accordingly, the nuclear forensics community has requested SRMs be produced that mimic post-detonation fallout debris that include actinides, urban materials, fission products, and activation products. In particular, it is a challenge to provide SRMs that contain short-lived nuclides that would be representative of a debris sample collected just after a nuclear explosion. The National Institute of Standards and Technology (NIST), in concert with partner labs (FBI (DOJ) and NPL) and with support from the FBI, have developed two Surrogate Post-Detonation Urban Debris (SPUD) SRMs – SRM 4600 and 4601. These materials are doped with varying amounts and isotopes of Uranium. These SRMs have been developed to mimic the 'rubble' of a city after an Improvised Nuclear Device (IND) detonation, and are capable of producing fresh fission as well as activation products. NIST SPUD samples were irradiated at The University of Texas TRIGA reactor via both thermal neutron and epithermal neutron irradiation facilities. These materials were then analyzed via gamma-ray spectroscopy for short-lived, medium-lived, and long-lived fission and activation products. Log 210. DEVELOPMENT OF BORON CALIBRATION VIA K0 METHOD IN PROMPT GAMMA ACTIVATION ANALYSIS. Artnak, E.J. (1); Biegalski, S.R. (1, 2); Landsberger, S. (1); Ianno, N.J. (3); Alexander, D. (3). (1) The University of Texas at Austin. (2) Georgia Institute of Technology. (3) The University of Nebraska at Lincoln. The prompt gamma activation analysis (PGAA) facility at the Nuclear Engineering Teaching Laboratory at The University of Texas at Austin was utilized to quantify boron concentrations in boron carbide semiconductor films deposited on silicon substrates. Calibration was complicated by the unique and varying sample geometries analyzed. In addition, there was a dearth of solid materials with quantified boron concentrations to exploit for calibration purposes. For quantification of boron, the k0 method was applied utilizing aluminum as the reference material. Aluminum samples were manufactured with high tolerances to match the geometry of each sample of interest. Each boron carbide film sample and its congruent aluminum sample were measured in the PGAA system. The measured aluminum responses were utilized to standardize the measurements. A boron standard was created following a similar approach to that used by the National Institute of Standards and Technology (NIST). Quality control measurements using this standard show that the method provided accuracy to within 4% for boron quantification. Log 211. ELECTROCHEMICAL PRODUCTION OF URANIUM OXIDE MICRO-PARTICLES FROM IONIC LIQUID. Droessler, J.E. (1); Burger, P.V. (1); Chlistunoff, J.B. (1) ; Goff, G.S. (1); Lamont, S.P. (1); Tenner, T.J. (1); Williamson, T.L. (1). (1) Los Alamos National Laboratory. Ionic liquids (ILs) provide an inherently conductive media suitable as an electrolyte for electrochemical applications including the electrodeposition of f-elements. The anion and cation combination affect the physical properties of the resulting IL including the viscosity, hydrophobicity/hydrophilicity, and electrochemical window. In this work, uranium is electrochemically reduced from uranyl to uranium oxide at an electrode surface within an IL. The emphasis of this work is on the formation of dispersed micron sized uranium oxide particles for particle standards. Parameters affecting the resulting morphology of deposits were investigated which included: IL solution preparation, electrode substrates, electrochemical techniques and potentials. Electrodeposits were annealed and then examined under scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The uranium isotopic ratio will be determined using secondary ion mass spectrometry (SIMS). LA-UR-17-31147


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Log 212. OXIDATION AND EXTRACTION OF AMERICIUM(VI) FROM USED NUCLEAR FUEL USING 2-CM CENTRIFUGAL CONTACTORS. Law, J.D. (1); Mincher, B.J. (1); Tillotson, R.D. (1); Schmitt, N.C. (1); Grimes, T.S. (1). (1) Idaho National Laboratory. The separation of Am from the lanthanides and curium is a key step in proposed advanced fuel cycle scenarios. The partitioning and transmutation of Am is desirable to minimize the long-term heat load of material interred in a future high-level waste repository. Given only subtle chemistry differences within and between the ions of the trivalent actinide and lanthanide series, this separation is challenging; however, higher oxidation states of americium can be prepared and separated via solvent extraction. The Idaho National Laboratory has been researching methods to oxidize americium and to extract it from lanthanides as americium(VI), from molar nitric acid solutions. Previous efforts have identified sodium bismuthate as an effective oxidant, which enabled testing of the extraction of americium(VI) by tributyl phosphate and diamylamylphosphonate (DAAP). More recently, successful extraction of americium(VI) was demonstrated using diethylhexylbutyramide (DEHBA) as an extractant and 2-cm acrylic 3D-printed centrifugal contactors. With this system 70% extraction of Am was achieved (DAm=2.5). Results of the testing, along with a discussion of engineering challenges associated with this process are detailed. Log 213. 231Pa-235U MODEL AGES FOR CERTIFIED REFERENCE MATERIALS TO SUPPORT NUCLEAR FORENSICS. Denton, J.S.(1); Kayzar-Boggs, T.M.(1); Wende, A.M.(1); Kinman, W.S.(1); Cardon, A.M(1); Steiner, R.E.(1). (1) LANL. Radiochronometry applied to nuclear forensics involves calculating the model purification age of a nuclear material. If assumptions of complete removal of the daughter isotope are correct the amount of time since a nuclear material was produced, purified, or processed can be determined. This information can then be used to understand the history of a nuclear material and can be applied both to nuclear forensics and nuclear security. In order to obtain meaningful age information from a nuclear material, accurate and precise measurement of the parent to daughter (or grand-daughter) atom ratios are critical. Well-characterized radiochronometry reference materials are crucial to fully validate analytical methods and are integral to the quality assurance and quality control efforts. The most widely-used chronometer for nuclear materials is 230Th-234U but the 231Pa-235U chronometer can be used to support 230Th-234U model ages. Additionally the two chronometers can be used together to understand chemical fractionation in the nuclear fuel cycle. We present our 231Pa-235U radiochronometry research to date with respect to chemical separations and spike calibrations. We also report 231Pa-235U model purification dates for a number of widely-used uranium certified isotopic reference materials measured over the last two years at LANL. We compare and discuss our Pa-U model age with Th-U model ages for the same materials. These data support wider efforts to develop 231Pa-235U radiochronometry methods and contribute to the larger model age data set for CRMs, providing useful reference points for the nuclear forensics community. Log 214. DEFENSE THREAT REDUCTION AGENCY: OVERVIEW OF RESEARCH PRIORITIES AND REQUIREMENTS. Rolfes, J. (1); Petersen, D. (1). (1) Defense Threat Reduction Agency. The Defense Threat Reduction Agency safeguards the United States and her allies from weapons of mass destruction (WMD) by providing capabilities to reduce, eliminate, and counter the threat and mitigate its effects. The DTRA accomplishes its mission by investing in basic research efforts at universities, national labs and DoD service labs to better counter threats posed by WMD. We also facilitate productive relationships with other scientific organizations and seek to identify promising research efforts overseas. Through the Basic Research program, the DTRA recruits and trains scientists and engineers to develop a talented workforce for the future. Basic research is directed towards greater knowledge or understanding phenomena without regard to specific applications. The DTRA Basic Research Program pursues efforts within and across disciplines such as chemical science, computer/network science, materials science, mathematics, nuclear science, and physics. Research efforts are needed in the science of WMD sensing and recognition to advance capabilities to detect, identify, and characterize WMD materials. The talk/poster will focus on the background of the DTRA Basic Research program, provide some highlights of current research areas of interest, and outline the requirements for researchers funded by the DTRA Basic Research program.


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Log 215. Cs AND Sr ADSORPTION CAPABILITIES OF CLINOPTILOLITE. Sterba, J.H. (1); Welch, J. (1); Wallenko, F. (1); Sperrer, H. (1). (1) TU Wien, Atominstitut. The Sr and Cs adsorption capacities of LithoFill (TM), LithoGran (TM) and a competing product clinoptilolite samples were investigated by radioanalytical methods (Sr-85 and Cs-134 gamma spectroscopy) for their adsorption capabilities of Sr and Cs. The dependence of adsorption and adsorption rate on physical factors including temperature, acidity and ionic strength were assessed. In addition, the reversibility of adsorption under high ionic strength conditions was also examined. In general, cesium is more strongly adsorbed than strontium, adsorption yields are generally independent of temperature (from room temperature to 65 C) and adsorption is relatively rapid (identical results for 2 or 5 day adsorption times). As expected, increasing salt (NaCl) concentrations tend to reduce adsorption of cesium and strontium. Similarly decreasing pH (HCl concentration) tends to adversely affect adsorption capacity. In geneal, Cs adsorption ranges between 51.5 and 30.1 mg/g in LitoFill and LitoGran samples and between 28.9 - 22.4 mg/g in the competing product. For Sr adsorption, ranges are 27.2 - 1.1 mg/g and 8.3 - 0.6 mg/g respectively, leading to the conclusion that the higher content of clinoptilolite in the LitoFill /LitoGran samples results in better adsorption characteristics. Log 216. DEVELOPMENT OF A REAL-TIME IN-CORE NEUTRON MONITORING SYSTEM FOR NEUTRON FLUX VARIATIONS DURING NEUTRON ACTIVATION ANALYSIS. Stokley, M.B. (1,3); Biegalski, S.R. (1,2); Artnak, E.J. (1); Haas, D.A. (1); Kline, G. (1). (1) The University of Texas at Austin. (2) Georgia Institute of Technology. (3) U.S. Army. The pneumatic Neutron Activation Analysis (NAA) experimental facility within the Nuclear Engineering Teaching Laboratory (NETL) at The University of Texas at Austin is widely used for the measurement of trace elemental concentrations. For extremely short duration NAA irradiations, sample activation measurements vary by up to 10% from normalized values. The neutron monitoring instruments of the TRIGA Mark II nuclear research reactor were unable to detect small-localized variations in neutron population likely resulting in the observed error. The primary traditional method to reduce this uncertainty is to irradiate a traceable flux monitor sample in addition to the unknown. This method doubles the required sample prep, measurement, and analysis effort to the unknown samples alone. An in-core neutron monitoring system was designed and installed adjacent to the pneumatic NAA sample system terminus to track these localized fluctuations. This design consists of a 4.7 x 83 mm fission chamber fitted through an access hole within the upper grid plate of the reactor core and controlled by a National Instruments LabVIEW data logging program. A custom outer jacket was designed to ensure the sensitive region of the detector is laterally positioned within 1 inch of the NAA sample terminus and at the same vertical location. This system provides the capability of monitoring sample irradiance in real-time. In preliminary testing, the system was able to track short irradiation NAA sample variance to within 3% of normalized values. Thus, a significant reduction in the uncertainty of NAA measurements for trace elemental concentrations is achievable.


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Log 217. SYSTEMATIC BIAS IN THE 240Pu/239Pu ISOTOPIC RATIO OF PLUTONIUM ISOTOPIC STANDARD CRM138. Mathew, K.J. (1); Ottenfeld, C. (1); Keller, R. (1); Slemmons, A. (1). (1) Actinide Analytical Chemistry, Los Alamos National Laboratory. Plutonium certified reference materials (CRMs) 136, 137, and 138 were produced, characterized, and certified in the period 1966 through 1971 by the National Bureau of Standards (NBS). For the Pu isotopic characterization measurements using thermal ionization mass spectrometry (TIMS), assumption was made that uranium (U) and plutonium (Pu) are similarly fractionated in analytical measurements by TIMS. Gravimetric mixtures of 235U and 238U were measured along with the Pu CRMs. The difference between the measured isotopic ratio in U from the calculated value (based on the weights of the U isotopic end-members mixed to produce the gravimetric mixture) was attributed to mass fractionation. Modern mass spectrometry practitioners know that the magnitude of the isotopic fractionation in thermal ionization is different for U and Pu. Both the mass spectrometer instruments and the analytical methodologies evolved significantly since these NBS Pu isotopic standard characterizations. Given the excellent precision of modern TIMS and inductively coupled plasma (ICP) instruments, systematic biases at the major and minor isotope ratios of these Pu isotopic standards are to be expected. Studies on the major and minor isotope ratios of U CRMs indicated systematic bias in the certified ratios of several NBL CRMs. These biases have since been validated through analytical efforts at New Brunswick Laboratory (NBL). We present a systematic investigation of the 240Pu/239Pu major isotope ratio of weapons grade Pu isotopic CRM138. The 240Pu/239Pu isotope ratio is shown to be biased by ~0.08 %, larger than the bias seen in the major isotope ratio of any U CRM from NBL. LA-UR-17-30994. Log 218. BASIC CHARACTERIZATION OF URANIUM BY HIGH RESOLUTION GAMMA SPECTROSCOPY. Choi, H.D. (1); Kang, M.Y. (1); Kim, J. (2). (1) Seoul National University. (2) Korea Atomic Energy Research Institute. A basic characterization of uranium samples was performed using gamma- and X-ray spectroscopy. The studied uranium samples were eight types of certified reference materials (CRMs) with uranium-235 enrichments between 1% - 99%, and the measurements were performed over 24 hours using a high-resolution and high-purity planar germanium (HPGe) detector in a lead cage. A general peak analysis of the spectrum was performed using HyperGam, and the XK. region of the uranium spectra was analyzed via the multigroup method using HyperGam-U. The two results were integrated for further analysis of the peak identification and activity determination. The standard reference sources were used to calibrate the spectroscopy system, and the absolute detection efficiency was used to determine the isotopic activity and content. To obtain the absolute detection efficiency, an effective solid angle code, EXVol, was run for each sample. Hence, the peak activities and isotopic activities were determined, and then, the total U content and U-234, U-235, and U-238 isotopic contents were determined and compared with those of the certified reference values. A new method to determine the model age based on the ratio of the activities of Ra-223 and U-235 in the sample was studied, and the model age was compared with the known true age.


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Log 219. DETERMINATION OF CHEMICAL BURNUP OF IRRADIATED AGR2 US TRISO FUEL USING MODIFIED DAVIES-GRAY TITRATION FOR URANIUM ASSAY AND HYPHENATED HPIC-IDMS TECHNIQUE FOR ISOTOPE RATIO MEASUREMENTS. Keever, T.J. (1); Roach, B.D. (1); Ilgner, R.H. (1); Giaquinto, J.M. (1); Montgomery, F.C. (1). (1) Oak Ridge National Laboratory. Chemical burnup measurements of US TRISO fuel irradiation experiments were conducted by the Nuclear Analytical Chemical and Isotopics Laboratory (NACIL) at Oak Ridge National Laboratory (ORNL) by means of destructive analyses using a combination of Davies-Gray titrations and hyphenated High Pressure Ion Chromatography -Isotope Dilution Mass Spectrometry (HPIC-IDMS) technique. In a series of planned experiments, AGR-2 was the second test within the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program to test both UCO and UO2 US TRISO fuel on a larger scale for comparison studies to the first AGR-1 experiments. This project is a joint effort between Idaho National Laboratory (INL) where the TRISO fuel compacts were irradiated, and ORNL where the post-irradiated evaluations (PIE) of the irradiated TRISO fuel compacts were performed. The determination of chemical burnup for this fuel type required special considerations and effort compared to other fuel forms such as oxides, metals, or ceramics. Various challenges found during AGR-1 analyses were addressed with this study, including dissolution of the fuel compacts using a closed-loop dissolution rig such that plutonium was fully digested, precise and accurate uranium quantification of the irradiated fuel dissolutions using modified Davies-Gray determinations, and precise ICPMS isotope ratio measurements utilizing hyphenated HPIC-IDMS technique; a novel direct-separation capability to resolve interfering mass isobars and matrix effects which utilizes direct injection into the mass spectrometer. These techniques provided data for the burnup-relevant fission products: Cs-137 and Nd-148, as well as fissionable isotopes of plutonium. These AGR-2 burnup results will be presented as compared to the existing AGR-1 data.*Oak Ridge National Laboratory is managed by UT-Battelle for the Department of Energy under Contract DE-AC05-000R22725. This submission has been authored by a contractor of the U.S. Government under contract No. DE AC05-00OR22725. Accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for the U.S. Government purposes. Log 220. UO2 SINGLE CRYSTAL GROWTH AND CHARACTERIZATION FOR NEUTRON DETECTION. Bowen, T. (1); Kimani, M. (1,2); Mann, J.M. (1); Rickert, K. (3,4); Young, C. (4); Petrosky, J. (4). (1) Air Force Research Laboratory, Sensors Directorate. (2) KBRWyle, Aerospace Group. (3) Oak Ridge Institute for Science and Education. (4) Department of Engineering Physics, Air Force Institute of Technology. Direct conversion, neutron sensitive solid-state radiation detectors with good gamma ray discrimination are highly sought after for the detection of shielded special nuclear materials (SNM). The use of uranium dioxide (UO2) single crystals as a detection material has been pursued by several research groups due to the large reaction energy (~185 MeV) from a neutron induced fission event which is much greater than current detection schemes which rely on reaction energies between 2-6 MeV. The interaction of incident neutron with UO2 results in energetic fission fragments in the order of 165 MeV creating copious amounts of electron hole pairs detectable as an electrical signal. The primary technical challenge to the successful fabrication of UO2 devices is the lack of high quality (semiconductor grade) single crystals of UO2. Traditional melt growth techniques such as Czochralski are not applicable due to the high melting point (~2878 C) of UO2. Various melt growth techniques such as arc fusion, cold crucible, and solar furnace have successfully been used to grown UO2, but these crystals suffer from both thermal strain and oxygen nonstoichiometry. Crystal growth of UO2 by the hydrothermal synthesis technique is a new endeavor at AFRL. In this talk, we will present hydrothermal growth and characterization of UO2 single crystals on non-native substrates. X-ray diffraction was used to probe crystal quality and crystallographic orientation of the samples, while X-ray photoelectron spectroscopy determined the photoelectric work function of two crystal orientations. Preliminary proof-of-concept irradiation studies of a simple UO2 resistive detector will also be presented.


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Log 221. PRODUCTION OF A NEW PROTACTINIUM-231 REFERENCE MATERIAL. Williams, R.W. (1); Treinen, K.C. (1); Essex, R.M. (2). (1) Lawrence Livermore National Laboratory. (2) National Institute of Standards and Technology. A new 231Pa reference material is being developed with the support of the US Department of Homeland Security. The 231Pa units have been prepared at Lawrence Livermore National Laboratory and the reference value for the 231Pa content is being established through collaboration with metrologists at the National Physical Laboratory (UK), the National Research Council (Canada) and the National Institute of Standards and Technology (US). This material will simplify and improve the precision of calibrations of 233Pa spikes used for 231Pa analyses by mass spectrometry. Moreover, the metrological traceability established for this reference material will be transferred to those analyses, which is important for 235U-231Pa radiochronometry in a nuclear forensics investigation where analytical results may be used in legal proceedings. Currently, 233Pa spikes are calibrated by 1) gamma spectrometry, 2) mass spectrometry crosses with 231Pa derived from geologic samples assumed to be in secular equilibrium, or 3) allowing complete decay of 233Pa and measuring the 233U content. Each of these methods has drawbacks. The precision on a gamma spectrometry calibration is not optimal, and calibration by mass spectrometry crosses with geologic samples is a difficult and time-consuming process. The 233Pa decay approach is potentially the most accurate, but this method is not appropriate for nuclear forensics. The new 231Pa reference material will enable more rapid spike calibrations by mass spectrometry and simplify this challenging analysis. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-743123. Log 222. SINGLE CRYSTAL GROWTH OF ThO2, UO2, UXTh1-xO2, AND U3O8 REFERENCE MATERIALS. Mann, J.M. (1); Hunt,E. (1); Kimani, M. (1,2); Rickert, K. (3,4); Bowen, T. (1); Prusnick,T. (1,2); Dugan, C. (4); Petrosky, J. (4). (1) Air Force Research Laboratory, Sensors Directorate. (2) KBRWyle, Aerospace Group. (3) Oak Ridge Institute for Science and Education. (4) Department of Engineering Physics, Air Force Institute of Technology. As a result of the high melting points of thorium and uranium oxides (3377 °C for ThO2 and 2878 °C for UO2), single crystal samples are difficult to produce, making lycrystalline ceramic reference materials standard. The polycrystalline nature, however, is undesirable as different fabrications can result in variations in grain sizes, particle morphology, density, and orientation. This can be particularly problematic for UO2 ceramics, which undergo oxidation especially along the grain boundaries where a highly defect rich fluorite structure exists. Single crystal reference samples can provide a more consistent standard due to the inherent long range nature of the samples and homogeneous composition. Hydrothermal synthesis is a relatively low temperature technique which provides an alternative method to fabricate single crystals of highly refractory oxides. This technique has been successfully used at AFRL to develop single crystals of ThO2, UO2, UxTh1·xO2, and U3O8. Single crystals of ThO2 and UO2 have been grown with surface area in excess of 1cm2 and thicknesses of several millimeters. Additionally, these materials have been fabricated along multiple crystallographic planes, including (111), (100), (110), and (311). This talk will report the crystal growth and initial structural characterization of ThO2, UO2, UxTh1·xO2, and U3O8 single crystals and their potential for reference materials.


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Log 223. DEFECT AND QUALITY ANALYSIS OF ACTINIDE OXIDES WITH RAMAN SPECTROSCOPY. Rickert, K. (1); Kimani, M. (2,3); Prusnick, T. (2,3); Bowen, T. (3) Mann, J.M. (3); Dugan, C. (4); Petrosky, J. (4). (1) Oak Ridge Institute for Science and Education, Oak Ridge. (2) KBRWyle, Aerospace Group. (3) Air Force Research Laboratory, Sensors Directorate. (4) Department of Engineering Physics, Air Force Institute of Technology. Raman spectroscopy offers a quick, nondestructive analytical tool for obtaining structural information on actinide oxides. Samples ranging from bulk single crystals to powders can be analyzed using this technique while employing identical data collection parameters in each instance, which enables Raman spectroscopy to be used for research, forensics, and quality assurance. Raman has already been evaluated for these applications in actinide oxides, but the analyzed samples have been powder, microcrystals, or defected single crystals. We expand the known capabilities to high quality bulk single crystals, examining large samples of single crystal UO2 grown hydrothermally on seed crystals. Uniform surface composition can be assayed with a resolution of one micron and the crystal quality of newly grown material can be tracked as a function of distance from the original seed crystal. The standard Raman spectrum for UO2 obtained using 532nm excitation wavelength displays a vibrational peak near 440cm.1 and a longitudinal optic phonon peak near 560cm.1 with its overtone at 1145cm.1. The relative sample quality, oxygen stoichiometry, and specific defect types are discussed with relation to the relative intensities and widths of these three peaks. This UO2 analysis establishes a control set that is used as a point of comparison for other single crystal actinide systems, such as ThO2, UxTh1.xO2, and U3O8, which are compared to prior results obtained from powder samples. In using Raman, we have the ability to distinguish isostructural, but compositionally distinct, materials while retaining the ability to differentiate between structures. Log 224. COMBINING ACCURACY AND PRECISION OF TRACEABLE STANDARDS TO ESTIMATE UNCERTAINTIES IN TRACE ELEMENT CONTENT MEASUREMENTS. Schappert, M. (1); Montoya, D. (1); Aragon, S. (1); Rearick, M. (1); Xu, N. (1); Mathew, K.J. (1). (1) Actinide Analytical Chemistry, Los Alamos National Laboratory. The accuracy and precision systematic of traceable certified reference material (CRM) standards can be combined to estimate conservative estimates of the uncertainties that are achieved in analytical measurements in which such standards are analyzed in similar conditions as the unknown samples. For trace element content measurements in uranium matrices using inductively coupled plasma (ICP) measurements, CRM 124 series can be used for this purpose. For matrices where certified CRM standards are not available (for example plutonium and americium materials that are certified for trace element contents), consensus standards with values established through exchange programs can be used. In a recent analytical effort to characterize the trace element contents in plutonium materials, we used well characterized plutonium exchange standards as QC standards. The standards underwent the same preparation steps as the unknown samples and were analyzed in the same analytical sequence as the samples using similar instrumental methods. The accuracy and precision of these standards are combined to estimate uncertainty estimates for trace element contents. These uncertainty estimates are compared with uncertainties estimated following the guide to expression of uncertainty in measurements (GUM). For trace element content measurements using ICP-AES and ICP-MS instruments, the uncertainty estimates obtained by combining accuracy and precision of the standards are found to be more conservative than those calculated by model calculations following GUM methodology. The smaller GUM uncertainty estimates are potentially due to the excellent short-term (of the order of days) repeatability characteristics of modern ICP instrumentation. LA-UR-17-31180


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Log 225. MASS SPECTROMETRIC DETERMINATION OF Pb-210 IN ENVIRONMENTAL MATRICES AFTER CLOUD POINT EXTRACTION. Blanchet-Chouinard, G.(1); Baskaran, K.W.(1); Larivière, D.(1). (1) Laval University. Isotopes originating from U-238 decay series, such as Ra-226, Pb-210 and Po-210, if present in our environment, can contribute significantly to radiation exposure. The potential radiotoxicity of Pb-210 results from its relatively long half-life (t1/2 = 22.3y), the high energy associated with the ionising particles generated by its progeny, such as Po-210, and chemical similarity to alkaline earth elements. This last feature makes him difficult to isolate in complex environmental matrices. The maximum acceptable concentration for Pb-210 in drinking water is 0.2 Bq.L-1, the lowest amongst the naturally occurring radionuclides, which pose a challenge for its rapid and precise determination by radiometric and mass spectrometric approaches. Therefore, the biggest challenge for Pb-210 determination is to find an effective approach to selectively extract and preconcentrate this radionuclide. Several selective preconcentration techniques such as co-precipitation and extraction chromatography exist. Recently, cloud point extraction (CPE) has been used for the isolation and enrichment of radionuclides in a variety of matrices. The concept of CPE consists in the aggregation of surfactants containing the analyte of interest based on changes in experimental conditions (e.g. temperature). The efficiency and selectivity of the CPE systems are greatly dependent on the choice of the extracting agent. This presentation will highlights to analytical developments of a CPE methodology using crown ether for the detection of ultra-traces of Pb-210 in environmental matrices by tandem mass spectrometry. Log 226. USE OF NEURAL NETWORKS TO ANALYZE PULSE SHAPE DATA IN LOW-BACKGROUND DETECTORS COMPARED TO STANDARD PULSE SHAPE DISCRIMINATION (PSD) ANALYSIS. Mace, E.K. (1); Ward J.D. (1); Aalseth, C.E. (1). (1) Pacific Northwest National Laboratory. Pacific Northwest National Laboratory has collected years of data using ultra-low-background proportional counters in a shallow underground laboratory. This large dataset of events (gas-gain, micro-discharge, HV fluctuations, pile-up events, etc) was exploited to study the impact of using neural networks for data analysis compared to a simple pulse-shape discrimination (PSD) method. We find that the PSD method introduces false positives and false negatives for certain datasets; however, the neural network is able to correctly classify these events. This paper will describe the method used for training the neutral network, the analysis of challenge datasets, and a comparison between the standard approach (PSD analysis) and a neural network. Log 227. EXPERIMENTAL VALIDATION OF COINCIDENCE SUMMING CORRECTIONS FACTORS FOR X-RAY AND GAMMA-X-SUMMING EFFECTS. Jonsson S. (1); Kastlander J. (1); Ramebäck H. (1,2). (1) Swedish Defence Research Agency (FOI), Division of CBRN Defence and Security. (2) Chalmers University of Technology, Department of Chemistry and Chemical Engineering. Measurements of gamma emitting radionuclides using High Purity Germanium (HPGe) detectors is a widely used and well understood measurement technique. There are numerous of studies on systematic effects in gamma spectrometry such as self-attenuation within the sample and true coincidence summing. Different sofwares have been developed in order to calculate correction factors for these effects. With time these softwares have become better in producing equivalent results which has been shown in several inter comparison studies, particularly for p-type detectors. However, for detectors sensitive to low energy photons (n-type and extended range detectors) the results are still not unanimous. With these types of detectors the effects due to X-rays may become highly pronounced when measuring certain radionuclides. Both as a result from various X-ray combinations or gamma-X-summing effects. Often when different calculation codes are compared these studies are conducted with data from theoretical detectors or point sources with a limited number of radionuclides. However, as laboratories now more frequently purchase extended range detectors for regular measurements the need for correction factors for gamma-X-summing effects is also becoming of greater importance. This study is comparing three softwares, GESPECOR, VGSL and EFFTRAN. Furthermore, calculated correction factors are compared to experimentally measured correction factors for a real extended range detector and volume sources. This is done for a number of radionuclides known for their challenging characteristics, i.e. emitting X-ray and gamma-X-summing in cascade.


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Log 228. EVALUATION OF DIFFERENT METHODS FOR MEASURING Sr-89 AND Sr-90: UNCERTAINTY FOR THE DIFFERENT METHODS AS A FUNCTION OF ACTIVITY RATIO. Holmgren Rondahl, S. (1); Tovedal, A. (1); Ramebäck, H. (1,2). (1) Swedish Defence Research Agency (FOI), CBRN Defence and Security. (2) Chalmers University of Technology, Department of Chemistry and Chemical Engineering. In case of a radiological emergency situation, e.g. a nuclear reactor accident or a nuclear weapons detonation, analysis of radioactive strontium will be one of the most important measurements to consider. The radionuclides to consider are 90Sr, a long-lived beta emitting radionuclide with a high energy beta emitting progeny (90Y), and the high energy beta emitting radionuclide 89Sr. During the first period of time after an accident, 89Sr will be the predominant radioisotope of strontium. The literature published to date in this area consists of a multitude of methods claiming to be the one to deliver measurement results in the shortest amount of time after an incident. Many methods make use of chemical separation followed by radiometric measurements, taking advantage of the opportunity to measure 90Y discriminately by its high energy beta-radiation (Emax(ß-) = 2 279 keV) using Cherenkov measurement on a liquid scintillation counter (LSC). The literature also describes methods using e.g. deconvolution of LSC-spectra, or subtracting contributions from different measurement windows when measuring by LSC. All methods are valid and applicable when measuring samples containing only 90Sr and to some extent at moderate activity ratios. However, in case of a radiological emergency situation the activity of 89Sr relative to 90Sr will increase, therefore the method of choice needs to be sufficiently robust and precise, especially from an uncertainty perspective, in order to be useful in a decision making process. Log 229. PRODUCTION POSSIBILITY OF TERBIUM-161 UTILIZING SECONDARY NEUTRONS GENERATED BY PROTONS FROM A LOW-ENERGY CYCLOTRON ONTO AN ISOTOPE PRODUCTION TARGET. Szelecsényi, F. (1); A. Fenyvesi, A. (1); Steyn, G.F. (2); Brezovcsik, K. (1); Kovács, Z. (1); Bíró, B. (1). (1) Cyclotron Application Laboratory, ATOMKI, Hungary. (2) iThemba LABS, South Africa. There is a growing interest in the possible practical applications of secondary neutrons generated on medical radioisotope production targets during routine bombardments. High-intensity target stations are becoming more abundant, with beam currents up to 1 mA in some cases. An intense flux of energetic neutrons close to the target surface can thus be obtained. We investigated the production of the therapeutic isotope Tb-161 via the Gd-160(n,g)Gd-161=>Tb-161 nuclear process using secondary neutrons generated by irradiating a Be-9 target with 18 MeV protons extracted from the MGC-20E cyclotron in Debrecen. With a beam current of 20 micro-A, a neutron flux of 2.5E9 neutrons per square cm per second could be achieved at an irradiation position 8 cm downstream from the target's back surface. A 340 mg Gd2O3 sample was activated for 20 h at this position. Afterwards, the produced Tb-161 was separated from the sample and its activity measured via the 74.57 keV (10.2%) gamma-line. The experimental yields of Tb-161 and all other identified radioisotopes are compared with predictions based on excitation functions from the TENDL-2015 library in conjunction with the neutron spectrum of the Be+p source as given by a full simulation of the irradiation set-up with the Monte Carlo code MCNP6.1. Acceptable agreement has been obtained for the majority of the produced radioisotopes. It is estimated that activation of a highly enriched Gd-160 sample for 2-3 days will achieve the requirements of a proposed labeling study.


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Log 230. PREDICTION OF 129IODINE SORPTION AND MOBILITY IN THE SOIL VADOSE ZONE USING LONG-TERM COLUMN EXPERIMENTS WITH IODIDE AND IODATE. Koehler, F. (1); Hoelzer, A. (1); Riebe, B. (1); Koenig, C. (1); Gorny, M. (1); Walther, C. (1). (1) Institute for Radioecology and Radiation Protection. 129I is emitted continuously in large amounts by reprocessing plants in La Hague and Sellafield, which lead to an increase of the isotopic ratios 129I/127I from some 10E-12 in the pre-nuclear age to 10E-7 or above in parts of Europe, today. Due to its long half-life (15 Mio y) and rather high mobility, 129I is also an important fission product to be considered for the long-term assessment of nuclear waste disposal. Many aspects of iodine chemistry in the environment are already known, particularly the dominant role of organics and clay in iodine soil interaction. However, detailed process understanding, relevant for radioecological and geochemical modelling, is still missing for many aspects. We report on experiments on German reference soil [REF], proving high sorption at low iodine concentrations of [I] = 10E-8 M compared to low sorption at higher concentrations [I] = 10E-4 M. Speciation is performed by a sequential extraction procedure. Different experimental setups are used: A) Natural soil samples are contacted with iodine solution over a time period of 180 days at constant solution level at the bottom of the soil column. To achieve a homogeneous distribution of iodine throughout the column by capillary action, an air filled space is kept on top of the soil inside the column. B) Different iodine species are characterized and quantified by ion-chromatography-ICP-MS of extracted pore water. This setup uses a circular flow through a column and is applicable for modelling iodine binding in soils under the phreatic water level for different contact times. Log 231. DIRECT LOW-ENERGY MEASUREMENT OF Ar-37 AND Xr-127 IN A RADIOTRACER GAS USING LOW-BACKGROUND PROPORTIONAL COUNTERS. Mace, E.K. (1); Aalseth, C.E. (1); McIntyre, J.I. (1); Williams, R.M. (1); Johnson, C.M. (1). (1) Pacific Northwest National Laboratory. A radiotracer gas with a blend of Ar-37 and Xe-127 was created in a research reactor for use in a gas migration experiment at the Nevada Nuclear Security Site (NNSS). The radiotracer gas was injected into a former underground nuclear explosion shot cavity and allowed to migrate naturally over the period of a year. Argon-37 is expected to be produced in an underground nuclear explosion and is created primarily via neutron capture on calcium (e.g. in soil); it also has a relatively long half-life of 35.0 days. Xenon-127 was chosen as a surrogate over the standard fission-product xenon isotopes with half-lives between 9-hrs and 11.8-days; Xe-127 has a longer half-life (36.4 days) which is comparable to the Ar-37 half-life. A radiotracer gas containing both Ar-37 and Xe-127 was characterized at Pacific Northwest National Laboratory (PNNL) using ultra-low-background proportional counters. A low-energy measurement technique was developed to directly measure the dual-isotope radiotracer gas for the Ar-37 Auger electron peak at 2.82-keV and the L-shell Auger electron peak for Xe-127 at about 4.5-keV. This measurement yielded activity concentrations of 138 Bq/cc and 412 Bq/cc and a ratio of 1:3 for Ar-37 and Xe-127, respectively, referenced to 7/11/2016 at 12 pm. This paper describes 1) the development of a low-energy method for direct measurement of Ar-37 and Xe-127 and 2) the spectral measurement and analysis of a dual-isotope radiotracer gas to quantify the activity of Ar-37 and Xe-127 for a gas migration study.


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Log 232. FEASIBILITY STUDY OF ELECTRONIC COLLIMATION FOR A PORTABLE PGAA SYSTEM BASED ON A COMPTON TELESCOPE COINCIDENCE DETECTOR ARRAY. Chen-Mayer, H.H. (1), Livingston, R.A. (2), Riley, B.K. (3), Turkoglu, D.J. (4), Zeisler, R. U (1). (1) Material Measurement Laboratory, NIST. (2) Department of Materials Science, University of Maryland. (3) University of Kentucky. (4) NIST Center for Neutron Research. Prompt gamma activation analysis (PGAA) based on a portable neutron source is desirable for the nondestructive inspection of concrete structures at risk for chloride-promoted corrosion. This field measurement currently provides only a bulk average with poor spatial resolution, due to the impracticality of heavy physical collimation needed for high-energy (MeV) gamma ray emissions. Therefore, using electronic collimation to constrain the sampled volume is especially attractive for this application. We report a preliminary investigation of such a concept by employing the principle of the Compton telescope with a pair of detectors -- a sodium iodide scintillation detector (scatterer) mounted in front of a HPGe detector (absorber) -- operating in coincidence mode. A gamma ray, after Compton scattering in the NaI detector, enters the HPGe detector with a well-defined correlation between energy loss and scattered angle. By specifying the time window for coincidence between the scatter and absorption events, only Compton-scattered photons events are counted. Further, by adjusting the energy discrimination of the scatter events in the NaI detector, the scattering angle can be determined from the energy peak shift in the HPGe detector spectrum, thereby providing spatial information. We studied the electronic parameters involved in coincidence operation with a Cs-137 point source and with the 2.2 MeV H capture gamma ray at the NCNR cold neutron beam PGAA instrument, as well as simulations of the measurement system using GEANT4. Preliminary results show that a point source displacement of a few centimeters is resolvable using the current pair of single-pixel detectors. Log 233. 231Pa-235U AGE-DATING OF RADIOCHRONOMETRY CERTIFIED REFERENCE MATERIALS FOR NUCLEAR FORENSICS. Treinen, K.C. (1); Gaffney, A.M. (1); Rolison, J.M. (1); Samperton, K.M. (1); Williams, R.W. (1). (1) Lawrence Livermore National Laboratory. The application of multiple radiochronometers in a forensic investigation of bulk uranium provides increased confidence for interpreting age-dating results. Well-characterized radiochronometry certified reference materials (CRMs) act as invaluable quality control standards in analysis of 'unknown' nuclear forensic samples. We have developed a streamlined method for the purification of Pa and Th from a sample of bulk uranium, and have applied this method in analyzing uranium radiochronometry CRMs IRMM-1000a and CRM 125A, using the 231Pa-235U and 230Th-234U chronometers. Our method includes 1) an improved 237Np-233Pa separation procedure for preparation of 233Pa spikes, 2) a simplified 233Pa spike calibration approach utilizing an in-house 231Pa standard, 3) revised separation and purification chemistry, and 4) refined data reduction algorithms, producing more accurate corrections and analytical uncertainties for Pa isotopic ratio analysis. Precise and accurate results for age-dating results are dependent on proper calibration of spike materials (e.g., 233Pa and 229Th) used in isotope dilution mass spectrometry. Our improved 233Pa spike calibration technique has replaced the time-intensive, conventional calibration using geologic rock standards. We have also incorporated into our workflow a recently-available, mass-certified NIST 229Th nuclear forensic reference material. These improvements yield reproducible 231Pa/235U and 230Th/234U measurements for radiochronometry CRMs using independently prepared and calibrated 233Pa spikes, as well as multiple calibrated 229Th and 233U spikes. Paired Pa-U and Th-U age-dating analyses of CRM-125A produce concordant results. In contrast, analyses of IRMM-1000a demonstrate reproducibly-discordant Th-U and Pa-U age-dates. Prepared by LLNL under Contract DE-AC52-07NA27344; LLNL-ABS-743120.


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Log 234. STUDIES OF ARSENOLIPIDS IN FRESH-WATER AND MARINE FISH SAMPLES USING CHEMICAL SEPARATION, HPLC AND NEUTRON ACTIVATION. Shi, Y. (1,2); Chatt, A. (1). (1) Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Canada. (2) Present Address: Isotopic Analysis Section, Analytical Chemistry Branch, Canadian Nuclear Laboratories, Atomic Energy of Canada Limited, Canada. Seafood is known to contain relatively high levels of arsenic and the toxicity of this element is dependent on its chemical form. For speciation of arsenic, the extraction of arsenic compounds from seafood samples is an important step. Methanol-water mixtures and methanol-water-chloroform mixed solvents were employed by many researchers to extract lipid-bound arsenic species from fish or similar organisms. A new method consisting of methanol-MIBK-water extraction and open-column cation exchange chromatography followed by HPLC separations was developed here in conjunction with neutron activation for the determination of total, residual, lipid-soluble, and five water soluble species including AsB, MMA, DMA, As(III), and As(V) in Canadian seafood samples. The samples were irradiated for 20-30 min at a fission neutron flux of 5x10E+11 cmE-2 sE-1 at the Dalhousie University SLOWPOKE-2 reactor facility, allowed to decay for 7-10 d and counted for 3-5 h. The detection limit for arsenic was less than 10 microgram per kilogram. The method was validated by analyzing several NIST and NRC reference materials. The levels of arsenolipids in marine and fresh-water fish samples were found to be low (~ 0.17 milligram per kilogram) followed by canned marine fish (~ 0.5 milligram per kilogram). The results obtained in this work indicate that the higher the lipid content the higher is the lipid-soluble arsenic in the seafood. Log 235. AN ANALYTICAL FIGURE OF MERIT TERM TO ASSESS THE ADVANTAGES OF ANTICOINCIDENCE GAMMA-RAY SPECTROMETRY IN NEUTRON ACTIVATION ANALYSIS. Zhang W. (1,2); Chatt A. (1). (1) Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Canada. (2) Present Address: Radiation Protection Bureau of Health Canada. One of the most important advantages of anticoincidence counting is the substantial decrease of background activity leading to improved detection limits. Anticoincidence counting has been successfully applied to the analysis of several trace elements, such as iodine, vanadium, and copper, using their short-lived nuclides. A disadvantage for this counting technique, however, is the reduction of a gamma-ray peak area if cascade decay mode is involved. To evaluate the advantages of anticoincidence counting is therefore not an easy task. Several attempts have been made in the past to derive a general equation for assessing the advantages of using anticoincidence counting for different nuclides and sample matrices. But many of these approaches appear not to be practical for real samples. In the present work we attempted to define an analytical figure of merit (AFOM) term for assessing the advantages of anticoincidence counting which would satisfy the following requirements. This term should (i) take into account most of the parameters related to sensitivity of a peak, such as resolution, peak area, background around the peak, dead time, counting time, and counting statistics; (ii) be general and should represent changes in the sample matrix composition; and (iii) provide parameters that can be easily measured. In order to demonstrate the effectiveness of the AFOM term developed in this work, 15 biological reference materials (RM) and standard reference materials (SRM) supplied by NIST and one RM by IAEA were analyzed for Mg and Cl by INAA. Details will be presented.


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Log 236. SEPARATION OF Au AND Pt USING TRIBUTYL PHOSPHATE RESIN. Morrison, S.S. (1); Uhnak, N.E. (1); Edwards, A.C. (1); Seiner, B.N. (1). (1) Pacific Northwest National Laboratory. A separation procedure was developed and implemented for the isolation of gold (Au) and platinum (Pt) radionuclides using tri-butyl phosphate (TBP) resin. Distribution coefficients were determined for Au and Pt in hydrochloric acid (HCl) and nitric acid (HNO3). The optimal separation condition was loading the sample in 9 M HCl (retention of Au and no retention of Pt), followed by Au elution in 8 M HNO3. This separation procedure was implemented on a deuteron-irradiated Pt foil that was dissolved after irradiation. Initial gamma screening of an aliquot of the dissolved foil detected the following radionuclides: Pt-197, Au-196, Au-198, and Au-199. Both Pt-191 and Pt-195 were not detected because their respective minimum detectable activities were too high due to the Compton background. Therefore, the dissolved foil was split into a quadruplicate sample set and processed through the TBP separation procedure. For the isolated Pt fractions, 98 ± 2% of the Pt was recovered, and both Pt-191 and Pt-195 were above their detection limits and quantifiable. There was no detectable Au radionuclides in the Pt fractions, equating to a decontamination factor of 6400 ± 800 for Au removal (n=4, ±1σ). For the Au fraction, 92 ± 7% of the Au was recovered and no detectable Pt-197 was present, equating to a decontamination factor of 830 ± 30 for Pt removal (n=4, ± 1σ). In summary, a separation procedure was developed and its performance examined for Au and Pt radionuclide separation using TBP resin. Log 237. NEUTRON DEPTH PROFILING AT CARR. Xiao, C. (1); Shi, C. (1); Yao, Y. (1); Tang, C. (1); Liu, X. (1); Yun, W. (1); Jin, X. (1); Wang, P. (1); Ni, B. (1). (1) Nuclear Analytical Laboratory, Department of Nuclear Physics, China Institute of Atomic Energy, China. A neutron depth profiling (NDP) has been established at China Advance Research Reactor (CARR). The NDP equipment can be used with thermal neutron and cold neutron beam. An inverse iteration method was used for B (or Li) depth profiling based on the NDP equipment. SRM2137 was used to verify the method. Based on the equipment and quantitative method, boron profiling in high temperature alloys and Lithium depth profiling in film were determined. Log 239. SPECTROSCOPIC NOBLE GAS STACK MONITOR WITH CONTINOUS UNATTENDED OPERATION AND ANALYSIS. Zickefoose, J.K. (1); Burnett, J.L. (2); Persson, H. (1); Huckins, B. (1); Anderson, T. (1), Mueller, W. (1); Oginni, B. (1); Jokerst, T. (1), Bronson, F. (1). (1) Mirion Technologies (Canberra) Inc. (2) PNNL. A spectroscopic stack monitoring system for the measurement of noble gasses discharged from medical isotope production facility stacks has been designed and a prototype constructed. The prototype is based on a Marinelli beaker style HPGe measurement operating in a continuous acquisition mode. Continuous acquisition is accomplished with novel software/hardware which allows for unattended acquisition, analysis, and storage of data over multiple workflow definitions. Since multiple averaging times are allowed for a single data stream it is possible to attain both swift reaction times as well as very low minimum detectable concentrations. Furthermore, since the release of noble gasses may be in short bursts of high concentration, the system was fit with a transistor reset preamplifier which allows for spectroscopic analysis up to and beyond 500,000 counts per second. As a direct result of the multiple averaging times and the use of the transistor reset preamplifier, the dynamic range of the system covers nearly 8 orders of magnitude. The hardware/software aspects, system performance, and calibration methodology will be discussed.


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Log 240. CURRENT STATUS OF INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA) NUCLEAR FORENSIC SCIENCE COORDINATED RESEARCH PROJECTS AND FUTURE NEEDS FOR RESEARCH AND DEVELOPMENT. Davydov, J. (1); Smith, D. (1); Tsvetkov, T. (1); Liu, D. (1). (1) International Atomic Energy Agency, Austria. As a means to prevent and respond to nuclear security events, nuclear forensic science provides information on the origin and history of nuclear and other radioactive materials out of regulatory control in the context of international legal instruments and national laws related to nuclear security. As nuclear forensic science supports law enforcement investigations and nuclear security vulnerability assessments, confidence in the analytical findings derived from a nuclear forensics examination is essential. Confidence in a nuclear forensic science examination is not contingent upon a single technology but rather from demonstrated confidence following laboratory analysis and interpretation of resultant data. The International Atomic Energy Agency (IAEA), through its Coordinated Research Projects (CRP), provides a opportunity for Member States to develop scientifically validated and objective solutions to promote confidence in findings, as well as provide a venue for nuclear forensic examiners to share experiences, best practices and lessons learned in analyzing nuclear materials (for more information: https://cra.iaea.org/cra/index.html). The IAEA's nuclear forensic science CRPs aim to deepen understanding of nuclear forensics signatures and the relationship between signatures to link people, places and things, and thus build confidence in conclusions. Beginning in 2018, the IAEA plans to launch its third nuclear forensics CRP entitled, Applying Nuclear Forensic Science to Meet Investigative Needs: Implementation Serving Nuclear Security. With a focus on both developing and developed States, this CRP seeks to use a broad range of experience and capabilities to develop and validate methods in support of the needs to law enforcement and nuclear security. Log 241. INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA) NUCLEAR FORENSIC SCIENCE CAPACITY BUILDING PROGRAM. Jerry Davydov (1), David Smith (1), Timofey Tsvetkov (1), Daming Liu (1). (1) International Atomic Energy Agency, Vienna International Centre PO Box 100, 1400 Vienna, Austria The International Atomic Energy Agency's (IAEA) objective in nuclear security is to contribute to global efforts to achieve effective security wherever nuclear and radioactive material is in use, storage, and/or transport and of associate facilities. Starting in the 1970s, the IAEA began providing ad hoc training courses in nuclear security. In the four subsequent decades, the IAEA has continued to emphasize a robust capacity building program as a key component of its assistance to States. In order to meet its nuclear security objectives, the IAEA assists States to develop, sustain and advance indigenous nuclear forensic science capabilities through nuclear forensics expertise development programs. The IAEA's capacity building program in nuclear forensics features classroom and hands-on laboratory based trainings, dedicated three-month residential assignments, technical visits, seminars, and expert meetings and missions. As nuclear forensic science supports law enforcement investigations and nuclear security vulnerability assessments, strategies for developing, testing and sustaining nuclear forensics capacities are essential in enabling a suitable response to a nuclear security event. As such, the IAEA has emphasized practical applications of nuclear forensic science in its capacity building program, to include infrastructure, legal and regulatory frameworks, operations, specialized equipment and sustainability. To ensure an enduring nuclear forensics workforce, the IAEA continues to develop the next generation of nuclear forensics practitioners by creating cross-disciplinary opportunities for law enforcement and nuclear security practitioners. The outcomes and findings from these offerings are used to reinforce existing initiatives and provide new ideas to improve the response to a nuclear security event.


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Log 243. URANIUM BINDING BY DESFERRIOXAMINE B: FROM AQUEOS SOLUTION TO SOIL STUDIES. Sladkov, V. (1); Meyer, M. (2); Sornosa-Ten, A. (2); Amarasinghe, S. (2); Nguyen , L.V. (2); Bourdillon, Mélanie (2); Fodor, Tamas (2); Stern, Christine (2); Roques, Jérôme(1); Coppin, Frédéric (3); Février, L. (3); Pierrisnard, S. (3). (1) Institut de Physique Nucléaire d'Orsay (IPNO), France. (2) Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), Université de Bourgogne - Franche-Comté, France. (3) Institut de Radioprotection et de Sûreté Nucléaire (IRSN), France. Besides the natural occurrence of uranium, its redistribution in the environment is intimately related to industrial activities. The principal sources responsible for uranium dispersion in the biosphere and the contamination of soils, sediments, and water encompass the entire nuclear fuel cycle from mining to nuclear waste processing, the military use of depleted uranium, coal burning, and spreading of phosphate-rich fertilizers. The environmental impact strongly depends on the mobility of a given radionuclide. Among a variety of possible geochemical processes, complex formation with organic species present in the environment plays an important role in the mobility. Predicting and modeling the metal speciation in waters and soils requires an accurate knowledge of the thermodynamic parameters related to the complex formation equilibria. Here we are interested in the interaction of uranium(VI) with desferrioxamine B (DFB), a siderophore excreted by the bacteria Streptomyces pilosus. Siderophores are ubiquitous, high-affinity iron(III) chelators excreted by virtually all bacteria and yeasts under iron-stress conditions. Hydroxamates are common bidentate chelating groups found in many siderophores. As their concentration in soils is in the ug/kg range, these compounds might significantly increase the solubility, migration rate, and bioavailability of highly-toxic actinides in case of environmental contamination. The uranyl/DFB speciation has been inferred from potentiometric, spectrophotometric and Raman titrations combined with NMR and capillary electrophoretic measurements. Raman and X-ray absorption spectroscopies together with DFT calculations enabled to probe the chemical environment around the uranium center in the different species. Finally, uranium dissolution tests performed with UO2-rich soils (pitchblende) will be presented. Log 244. CHEMICAL SEPARATIONS FOR ACCELERATOR MASS SPECTROMETRIC QUANTIFICATION OF MANGANESE/MANGANESE-53 AND IRON/IRON-60 RATIOS. Koll, D. (1); Korschinek, G. (1); Scherfler, G.(2); Welch, J.M.(2). (1) Department Physik, TU München; Germany. (2) TU Wien, Atominstitut, Austria. Quantification of long-lived cosmogenic radioisotopes (e.g. Ca-41, Mn-53 and Fe-60) of trace elements from the environment by accelerator mass spectrometry (AMS) requires chemical separation techniques capable of very effectively suppressing stable isobaric interferences (e.g. K-41, Cr-53 and Ni-60) while minimizing (or eliminating) sample loss. In order to analyze 0.5t of Antarctic Snow-melt, anion exchange processes have been optimized for Fe-Ni separation on ~1 mg scale and Cr-Mn separation on 100ug scale using Fe-59, Mn-54 and Cr-51 radiotracers combined with gamma spectroscopy. Separation profiles gathered using gamma spectroscopic data show that at the scale required Fe-Ni are easily separated on small (mass of resin) columns of Dowex 1x8 (mesh) by introduction in 10 M HCl and elution of Ni with 6M HCl followed by elution of Fe with water. However, separation profiles determined by gamma spectroscopy show the efficient separation of Cr from Mn to be much more challenging. Introduction of a mixture of Cr and Mn in 10 M HCl followed by elution of Cr and subsequent elution of Mn with 7 M HCl yields a certain degree of separation, highly dependent on the specific conditions (column size, flow rates, analyte concentrations). Attempts have been made to prepare inactive chemistry blanks for AMS background optimization from control solutions designed to imitate the environmental material to be studied. The results of these studies will be presented.


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Log 245. MEASURING MOLTEN SALT MASS WITH Na-22 TRACER. Hardtmayer, D.E. (1); Herminghuysen, K. (2); White, S. (2); Kauffman, A. (2); Li, S. (3); Sanders, J. (3); Cao, L. (1). (1) Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering (2) Nuclear Reactor Laboratory, College of Engineering, The Ohio State University. (3) Fuel Cycle Science and Technology, Idaho National Laboratory. A longstanding challenge with any irregularly shaped molten salt container is determining the mass of the molten salt that it holds. A previously validated method, termed radioactive tracer dilution, was validated at benchtop scale, under a collaborative project of the Idaho National Laboratory and The Ohio State University, using Na-22 and was proven to be an accurate way to determine salt mass with limited assumptions. Continuing on this work, it was decided to more closely resemble the radioactive molten salt environment on a benchtop scale, in order to determine the minimum amount of tracer that would need to be added to ensure accuracy, with a larger interference from one of the major fission products, Cs-137. Simulation work was done to estimate what a theoretical gamma spectrum of the container, and the ratio of Cs-137 to Eu-154. Based on the recommendations of these simulated results, ratios of Cs-137, Eu-154, and Na-22 were added to 100 grams of LiCl-KCL salt, and gamma spectrums were acquired from this mixture. After heating, mixing, and sampling of a LiCl-KCl salt, it was determined that Na-22 can be used as an accurate tracer element in a highly radioactive environment and that the existing fission product,Cs-137, would not affect the accuracy of the method. Log 246. MAPPING DISTRIBUTED RADIOLOGICAL SOURCES IN COMPLEX TOPOGRAPHIES WITHIN THE ARES ADVANCED TECHNOLOGY DEMONSTRATION. Joshi, T.H. (1); Quiter, B.J. (1); Bandstra, M.S. (1). (1) Lawrence Berkeley National Laboratory. Aerial gamma-ray measurements are a powerful method for mapping distributed radiological sources over large areas. Mapping of natural background constituents such as Potassium-40 and the primordial Uranium and Thorium decay chains is commonly used in geologic survey, while mapping synthetic sources is important to emergency response and environmental assessment and remediation. The accuracy with which distributed sources can be mapped is limited by flight altitude, path, and duration as well as the angular response of the detector system, knowledge of the system pose throughout the flight, and knowledge of the local topography. The goal of the Airborne Radiological Enhanced-sensor System (ARES) Advanced Technology Demonstration was to improve the latter parameters, respectively, by employing an active masked detector array, and inclusion of inertial navigation system data and detailed topographic databases. Data were collected with ARES over regions with complex topography including areas of rugged terrain as well as urban areas with large structures. Using this data and regularized Maximum Likelihood-Expectation Maximization, we present quantitative maps of both natural and synthetic distributed radioactive sources, and compare to ground-truth where available. Log 247. MEASUREMENT OF ACTINIDES IN HAIR AND NAIL SAMPLES COLLECTED FROM OCCUPATIONALLY EXPOSED WORKERS. Brockman, J.D. (1); Brown, J. W.N. (2); Morrell, J.S. (2); Robertson, J.D. (1, 2). (1) University of Missouri Research Reactor. (2) University of Missouri Chemistry Department. (3) Y12 National Security Complex. This work evaluates the use of hair, toenail, and fingernail as potential monitors of actinide exposure in occupationally exposed workers. Volunteers with potential occupational exposure were recruited from US national laboratories. The exposure of each case was assessed by self-reporting using a short questionnaire. Cases were compared to non-occupationally exposed control samples. Pu and U from the hair and nail samples were separated for analysis using stacked TEVA, UTEVA, and DGA columns. U and Pu isotope ratio measurements were made using a multi-collector ICP-MS equipped with a desolvating nebulizer. 5 of 7 cases that self-reported Pu exposure had measurable levels of 239Pu in hair and nail samples with concentrations ranging from 0.55 ng/kg to 0.78 ng/kg. In 6 cases that self-reported exposure to depleted or enriched U, non-natural a 235U/238U isotope ratio was measured. The U exposure cases also contained significant differences in the 236U/238U ratio compared to the controls. The work supports the continued examination of hair and nail as biomarkers for exposure to special nuclear materials.


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Log 248. PROBABILISTIC NEAR REAL-TIME FORENSIC RADIONUCLIDE IDENTIFICATION USING THE KALMAN FILTER. Kinn, D. (1), Biegalski, S. (2); Haas, D. (1); Burnett, J. (3); Keillor, M. (3). (1) The University of Texas at Austin. (2) Georgia Tech University. (3) Pacific Northwest National Laboratory. This research applies the Kalman filter to list mode gamma spectroscopy data from small-scale trials to produce initial mass estimates of decaying radionuclides for use in forensic analysis. The Kalman filter uses Bayesian inference to update its estimate of the initial state of the system as more gamma readings are detected, quickly determining the actual state of the system. The proposed benefits of this approach are quicker, near real-time estimation of the initial state of the system and greater accuracy than traditional peak analysis methods. Results will show the ability of the algorithm to identify initial masses on several trials using irradiated uranium oxide, cement, soil, and peach leaves as test materials. They also identify potential limiting factors, including reproducibility of detection geometry and sensitivity to variations in detector response. Log 249. COMPARISON OF METHODS FOR LOW-LEVEL RADIOCESIUM MEASUREMENTS IN OCEAN WATER SAMPLED OFF THE COAST OF JAPAN. Daum, J.K. (1); Aoyama, M. (2); Sudowe, R. (3). (1) Radiochemistry Program, University of Nevada Las Vegas. (2) Institute of Environmental Radioactivity, Fukushima University, Japan. (3) Department of Environmental & Radiological Health Sciences, Colorado State University. Nuclear operations conducted over the past seventy years have resulted in the contamination of the environment with potentially hazardous radioactive species. Atmospheric testing of nuclear weapons along with accidents such as the ones that occurred in Chernobyl, Ukraine and Fukushima, Japan are some of the major sources of anthropogenic radionuclides in the environment. Natural waters are the largest recipient of environmental contamination by anthropogenic radionuclides, with sea and ocean water covering more than two-thirds of the Earth's surface. Cesium-137 is one of the major anthropogenic radionuclides that has been released into the environment from atmospheric testing and nuclear accidents. It has a relatively long half-life (30.07 years) and high mobility within the environment. Radiocesium is commonly determined in ocean water samples using an improved ammonium phosphomolybdate (AMP) procedure developed by Aoyama et al. The scope of this work was to optimize extraction methods that utilize Cesium Resins (AMP-PAN and KNiF-PAN) from Triskem International and compare them with the standard AMP procedure for the determination of radiocesium in ocean water that was sampled off the coast of Japan (Tomioka, Fukushima). The two resins are based on either AMP or potassium nickel hexacyanoferrate(II) (KNiFC) as active components. Both Cesium Resins were characterized for solid and active component content as well as break point for cesium uptake.


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Log 250. CALCIUM INTERFERENCE ON AMERICIUM AND PLUTONIUM UPTAKE ON SIX EXTRACTION CHROMATOGRAPHIC RESINS. Daum, J.K. (1); Sudowe, R. (2). (1) Radiochemistry Program, University of Nevada Las Vegas. (2) Department of Environmental & Radiological Health Sciences, Colorado State University. Nuclear operations conducted over the past seventy years have resulted in the contamination of the environment with potentially hazardous radioactive species. Atmospheric testing of nuclear weapons along with accidents such as the ones that occurred in Chernobyl, Ukraine and Fukushima, Japan are some of the major sources of anthropogenic radionuclides in the environment. Natural waters are the largest recipient of environmental contamination by anthropogenic radionuclides, with sea and ocean water covering more than two-thirds of the Earth's surface. The elevated salinity of sea and ocean water results in a complex matrix that hinders the isolation, characterization, and determination of the radioisotopes of interest. In the aftermath of the reactor accident in Fukushima it has become obvious that there is a severe lack in methods that would allow the rapid determination of alpha and pure beta-emitting radionuclides in ocean water. Calcium, one of the main constituents of ocean water (1.18 % of total salinity; 0.416 ., 0.01038 M), has shown to be a major interferent when performing radioanalytical separations using extraction chromatographic resins, particularly DGA Resin. In this work, six different extraction chromatographic resins produced by Eichrom Technologies were characterized for their retention of americium and plutonium when varying amounts of calcium were introduced into the system. The capacity of the six resins for the calcium interferent was also determined. Log 251. ANALYSIS OF ACTINIDES: IMPORTANT THINGS WE FORGET. Tolmachev, S.Y. (1); Thomas, E.M. (1); Tabatadze, G. (1). U.S. Transuranium and Uranium Registries, Washington State University. The United States Transuranium and Uranium Registries (USTUR) studies actinide biokinetics and dosimetry by following up occupationally exposed former nuclear workers. The USTUR performed a study to verify standard analytical protocol used by the Registries for 238Pu and 239Pu analyses in human tissue samples. The reference soil (MAPEP-11-MaS24) certified for 239Pu (high-fired oxide), 241Am, 234U, and 238U concentrations was used. Samples were microwave digested at a control temperature of 200 ºC and monitored pressure of 40 bar for 20 minutes using concentrated HNO3-HCl-HF or HNO3-HCl acid mixture. Digested samples were spiked with 242Pu, 243Am, and 232U tracers and actinide separation was carried out using TEVA-TRU-DGA extraction chromatography. Following electrodeposition, activities of Pu, Am, and U fractions were measured by α-spectrometry. The average chemical tracer recoveries were 34.3±6.2%, 100.8±1.7%, and 98.3±4.9% for 243Am, 242Pu, and 232U, respectively. Low 243Am recovery was attributed to the soil matrix effect. Measured average concentrations of 239Pu, 241Am, 234U, and 238U in samples digested with HNO3-HCl-HF were 2.54±0.16, 1.64±0.12, 4.41±0.09, and 4.61±0.11 pCi g-1, respectively. These values were not statistically different from certified 239Pu, 241Am, 234U, and 238U concentrations with negative bias of the mean of 4.0%, 1.3%, 7.2%, and 7.0%, respectively. Using HNO3-HCl, only 5% of the initial 239Pu was dissolved. The remaining residue was digested with HNO3-HCl-HF and 239Pu concentration was calculated to be 2.42±0.10 pCi g-1 resulting in a combined value of 2.56±0.10 pCi g-1 (bias -3.4%). Negative bias of 77.6%, 72.1%, and 71.9% for 241Am, 234U, and 238U, respectively, was also observed with HNO3-HCl. Incomplete dissolution of the analyte using HNO3-HCl results in a low actinide recovery from the sample, while HNO3-HCl-HF allows for complete dissolution of all actinides present in soil, including high-fired plutonium oxide.


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Log 252. RECENT DEVELOPMENT AND MEASUREMENT ACTIVITIES AT THE NIST PGAA FACILITY. Chen-Mayer, H.H. (1); Turkoglu, D.J. (2); Paul, R.P. (1); Zeisler, R. U (1). (1) Materials Measurement Laboratory, NIST. (2) NIST Center for Neutron Research. The upgraded NIST PGAA facility at neutron guide D (NGD) has a factor of 10 gain in thermal-equivalent neutron flux over its predecessor at NG7. The radiation shielding at the NGD instrument was optimized using MCNP to minimize gamma-ray and fast-neutron background. The sensitivity and detection limit for measuring H, an important application of PGAA, have improved by a factor of two and six, respectively. The end position of NGD also affords the capacity for conducting several new measurement activities due to increased space and accessibility, including a larger sample chamber. A programmable beam shutter, with logic signals for gating spectra or list mode, has been installed upstream of the sample chamber to allow for delayed activation analysis of short-lived nuclei and precisely-timed cyclic irradiations. The additional space on the west side of the chamber have allowed experiments with additional detectors, such as a second HPGe detector or a Compton camera (an array of CZT detectors). Various gamma-gamma coincidence measurements have been carried out to study nuclear structure as well as to explore potential improvements in metrology. The concept of emission tomography has been tested for H, Ti and Cl prompt lines using Compton imaging cameras developed by the University of Maryland and H3D. The next phase of the instrument expansion will include a flight tube to a second sample chamber to accommodate the needs of users in a modular research station while keeping the current instrument in its standard measurement geometry, an important aspect for certifying standard reference materials. Log 253. PERFORMANCE ESTIMATION OF COINCIDENCE-BASED IMAGING SYSTEM FOR PROMPT GAMMA ACTIVATION IMAGING USING GEANT4 TOOLKIT. Lee, H.R. (1); Kim, J.S. (1). (1) Korea Atomic Energy Research Institute. To visualize the composition information of the volumetric samples, a prompt gamma activation imaging (PGAI) using the neutron beam has been utilized. Although an HPGe detector coupled with a single-slit collimator can visualize the elemental distribution of cultural heritage sample, a scanning method involved a time-consuming procedure. To overcome this limitation, a new imaging system, which could determine the 2D distribution of elemental information by using the coincidence logic, was proposed. For this, the imaging system consists of a calorimeter for the energy determination for the identification of elements and a position sensitive detector coupled with a parallel-hole collimator for the position determination. In the present study, to estimate the feasibility of the proposed system, we performed the Monte Carlo simulation using the Geant4 toolkit. The rectangular iron plate implanted with the L-shaped nickel was irradiated with the neutron beam, and the coincidence events were selected. For the coincidence events, we can identify the characteristic gamma-ray peaks for the iron (352, 7631 and 7645 keV) and the nickel (465 and 9889 keV). With the energy gate of 465 keV for the calorimeter, we also recognized the shape of implanted nickel from the 2D image obtained by the imaging system. Base on the results, we expects that the proposed imaging system can be utilized in the elemental analysis of volumetric samples by measuring the prompt gammas. Log 254. A FISSION-SPECTRUM NEUTRON BEAM AT A RESEARCH REACTOR: DESIGN AND MODELING. Barron, D. (1); Haas, D. (1). (1) The University of Texas at Austin. A fast neutron irradiation facility has been designed and modeled in MCNP for use in the Beam Port 4 facility at the TRIGA Mark-II reactor at The University of Texas at Austin. This facility seeks to reproduce the Watt fission spectrum by reducing the present thermal and epithermal neutron flux while leaving unscattered the fast flux of a light water reactor. The final neutron filter design was found to reduce the thermal neutron flux by a factor of 10E5 while maintaining 50% of the fast neutron flux. The large thermal neutron capture cross section of cadmium reduces heating from alpha reactions in boron such that heating in the filter is negligible. Sensitivity studies were performed to produce an economic facility in MCNP by reducing the amount of enriched 10B. It was found that a 10 x10 cm area of 96% 10B surrounded by elemental boron powder was an optimal economic configuration. The neutron flux to the sample closely resembles the 235U Watt fission spectrum with a slight elevation in the epithermal neutron flux.


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Log 255. TRACE IMPURITY ANALYSIS IN URANIUM OXIDE REFERENCE MATERIAL VIA GRAVIMETRIC STANDARD ADDITION AND ISOTOPE DILUTION MASS SPECTROMETRY. Tevepaugh, K. (1); Essex, R.M. (2); Giaquinto, J. (1); Metzger, S.C. (1); Ticknor, B.W. (1); Hexel, C.R. (1). (1) Oak Ridge National Laboratory. (2) National Institute of Standards and Technology. The analysis of trace impurities in uranium materials is essential in nuclear fuel production to meet specifications as well as in nuclear forensics and safeguards to establish signatures. In the following methods, quantification of trace impurities in uranium oxide was performed by either gravimetric standard addition or isotope dilution mass spectrometry (IDMS) with enriched isotope spikes followed by measurement on an inductively coupled plasma mass spectrometer. These analyses were performed due to involvement in a larger project aimed at certification of uranium oxide reference materials for 28 trace impurity concentrations. The two methods, standard addition and IDMS, provided an independent characterization versus the conventional matrix-matched external calibration method used in this type of analysis. CRM 124-1 and 124-6 from New Brunswisk Laboratory Program Office were used as controls for method validation, the results of which are presented here. *Oak Ridge National Laboratory is managed by UT-Battelle for the Department of Energy under Contract DE-AC05-000R22725. This submission has been authored by a contractor of the U.S. Government under contract No. DE AC05-00OR22725. Accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for the U.S. Government purposes. Log 256. DEVELOPMENT OF A HYBRID-THERANOSTIC-SYSTEM. Rosecker, V. (1, 2); Denk, C. (2); Maurer, M. (2); Mikula, H. (2). (1) TU Wien, Atominstitut. (2) TU Wien, Institute of Applied Synthetic Chemistry, Austria Knowledge of the biodistribution/pharmacokinetics (pK) of therapeutic radiopharmaceuticals is crucial for the effective application and calculation of patient radiation dose received. Commonly, biodistribution is visualized with positron or gamma emitters in nuclear imaging techniques as PET/SPECT. In case of significant target accumulation, the same agent bearing a radiotherapeutic metal is administered, assuming similar pharmacokinetics. However, the bound metal has a major impact on biodistribution. To overcome this issue we developed a hybrid-theranostic-system that can be applied to determine the pharmacokinetics of therapeutic radiometals by concomitant use of the short lived PET-isotope 18-F. This system consists of a precursor with two labeling sites such that the chemically identical molecule is available bearing inactive metal isotopes and an 18-F atom for pK-studies and imaging. The same molecule including the radiometal and inactive 19-F atom is available for therapy. Since the molecules are isotopically different but chemically identical, identical behavior in biological systems is expected. Using this approach, a variety of metals can be screened using only 18-F as radionuclide, thus avoiding barriers associated with testing certain radiometals (availability, cost, storage, licensing, waste disposal, etc). Furthermore, our hybrid nuclide scaffold bears a tetrazine-moiety for straightforward attachment of a targeting vector by bioorthogonal click chemistry. In this work, commonly known and established (radio)metals (166-Ho, 177-Lu, 90-Y) were used; prostate antigen specific ligand (PSMA) was attached as targeting vector. The (radio)synthesis of this click chemistry based hybrid-tracer-system will be presented and results of an in vitro prostate cancer uptake assay will be shown. Log 258. LESSONS LEARNED FROM THE POST-FUKUSHIMA FOOD MONITORING. Steinhauser, G. (1). (1) Leibniz University Hannover. The Fukushima nuclear accident has triggered the largest food monitoring campaign for radionuclides ever. In this presentation, we summarize some lessons learned from the huge data set gathered in this monitoring program. Our analyses will show a high degree of food safety in Japan. Radioecological mechanisms need to be understood in order to explain the factors that influence the contamination levels in foods and that are responsible for certain phenomena that are reflected in the data set.


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Log 259. URANIUM OXIDE SYNTHETIC PATHWAY DISCERNMENT THROUGH MORPHOLOGICAL ANALYSIS. Schwerdt, I.J. (1); Hawkins, C.G. (1); Taylor, B. (1); Brenkmann, A. (1); Martinson, S. (1); McDonald, L.W. IV (1). (1) Department of Civil and Environmental Engineering, University of Utah. When a sample of unknown nuclear material is interdicted, a nuclear forensic scientist has a number of techniques of varying speed and accuracy with which to analyze the history of the sample. Powder X-ray diffractometry (p-XRD) can rapidly provide information on the crystal structure of a sample. In the case of amorphous materials, or uranium oxides that share similar structures but resulted from different synthetic pathways, p-XRD has limited utility for attribution. Thermogravimetric analysis-mass spectrometry (TGA-MS) can provide signatures unique to the thermal decomposition of the unknown material through analysis of the temperature-dependent mass losses and the volatile decomposition products. It has been proposed that the surface morphologies of powder uranium oxides are often representative of the precipitation and calcination conditions experienced by the sample. Scanning electron microscopy (SEM) allows one to acquire images of the surface morphology at high magnification. Quantitative analysis of the size and shape of the microstructure may provide signatures indicative of the synthetic conditions for the material and its precursors. To determine the utility of these techniques to differentiate several common uranium ore concentrates (UOCs) and their calcination products, TGA-MS, DSC, p-XRD, and SEM quantitative morphological analysis were applied to compare several common uranium oxide synthesis pathways. Ammonium diuranate, uranyl peroxide, sodium diuranate, magnesium diuranate, and ammonium uranyl carbonate were synthesized from uranyl nitrate solutions. These precursors were then calcined in air at 400 °C and 800 °C to generate additional uranium oxides (e.g. UO3 and U3O8). UO2 was also produced from the various synthetic pathways utilizing a hydrogen gas reduction at 510C. P-XRD and extensive SEM image acquisition were performed at each step in the process. TGA-MS and DSC of the starting materials indicated temperature dependent dehydration, volatilization, and reduction events that were unique to each material. Quantitative morphological analysis utilizing the Morphological Analysis of MAterials(MAMA) software allowed the determination of statistically significant differences between the investigated uranium oxides. Log 260. NEW MEASUREMENT OF THE U-238 DECAY CONSTANT WITH INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY. Keller, C.B. (1,2); Parsons-Davis, T. (3); Wimpenny, J. (3); Williams, R. (3); Samperton, K. (3); Thomas, K. (3); Renne, P. (1,2); Mundil, R. (1); Moody, K. (3); Knight, K. (3); Kristo, M.J. (3). (1) Berkeley Geochronology Center. (2) Dept. Earth and Planetary Science, University of California Berkeley. (3) Lawrence Livermore National Laboratory. Radioisotopic dating techniques provide insight into the temporal histories of physical and chemical processes in materials related to planetary sciences and nuclear forensics. The ability of these techniques to quantify the passage of absolute time depends on accurate knowledge of decay constants and their corresponding uncertainties. The decay constants of 238U and 235U are particularly important to Planetary sciences, wherein the measured values with lowest reported uncertainties (Jaffey et al., 1971) are widely used directly, via 206Pb/238U and 207Pb/235U ratios, but also as constraints on other radioisotopic dating methods such as those based on 40K-40Ar. Despite heavy reliance on the data of Jaffey et al. (1971), they have never been independently verified to comparable precision in the subsequent decades. We have determined the 238U decay constant via measurement of 234Th ingrowth in chemically purified, isotopically enriched 238U solutions, by quantitative extraction of Th and complete decay to 234U. The method relies on 238U material with low 234U abundance, careful yield tracing, accurate measurements using the isotope dilution (ID) method with multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS), and a Monte Carlo uncertainty propagation method to account for covariances inherent in replication of the experiment for multiple aliquots. To reduce the uncertainty propagated from the 234Th decay constant, 234Th decay curves were measured with both a windowless gas-proportional counter and high-purity Ge (HPGe) gamma detector. Preliminary 238U results indicate a slightly higher decay constant value than that previously determined by defined-geometry alpha counting, but ongoing efforts to reduce experimental uncertainty are needed before results are conclusive. An overarching goal of the project is to ensure the quality of results, e.g. metrological traceability, to facilitate implementation across diverse disciplines.


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Log 261. DESIGN OF AN IN-CORE FAST NEUTRON IRRADIATION FACILITY WITH PNEUMATIC SAMPLE TRANSFER AT A RESEARCH REACTOR. De Luna, B.A. (1); Haas, D.A. (1); Barron, D.C. (1); Artnak, E.J. (1); Stokley, M. (1). (1) University of Texas at Austin. The objective of this work is the design and optimization of a fast neutron irradiation facility with pneumatic sample transfer for use in fast neutron activation analysis and reduce uncertainties in fast neutron induced fission product yields. Various materials and geometric designs were researched and modeled in MCNP for the filtration of thermal neutrons from a research reactor core. These tests yielded the finalized design of a layered cylindrical system to be placed in the 3-element irradiation position in the core of the TRIGA MARK-II reactor at The University of Texas at Austin. The filtration of thermal neutrons was compared to the effective fast neutron flux in the sample location and was weighed appropriately such that the highest possible fast neutron flux was achieved. The models indicate that thermal neutron flux may be reduced by at least five orders of magnitude while only reducing the overall fast neutron flux by less than an order of magnitude. The resulting fast: (thermal+epithermal) flux ratio should exceed 10,000:1 with a fast flux value of 3E11 n cm-2s-1. Log 262. PORTABLE RADIATION IRRADIATOR FOR REAL TIME PERFORMANCE CHECKING OF IN SITU RADIATION MONITORING SYSTEM. Han, J.H. (1); Kim, H. (1); Kim, S.J. (1). (1) Korea Basic Science Institute. Generally, radiation monitoring systems have no radioactive sources around detectors to monitor the change of performance and status in real time. It is because it will have radiation interferences, for example, higher background, lower MDA, spectral interferences etc. However, if in situ radiation monitoring systems can be checked the performance of monitoring systems by using standard radioactive source under suitable interference control, it will be highly improved the reliability of the data gotten from those operating in large environmental change. Irradiator to equip standard radiation source should be small size but sufficient shielding thickness. We optimized lead shield structure that is most critical parts on weight and size for adopted radionuclides to be small, light and simple. To estimate optimized thicknesses of lead shield for each gamma-ray energy of several radionuclides, the ratios between I, measured activity penetrating lead plates, and I0, no absorbance, was measured. The prototype irradiators with circular lead shield have been made and conducted for shielding ability test for low gamma-ray energy emitting radionuclides. Also performance change of 3X3 NaI detector with time was measured in air of indoor and in water of outdoor. Detector performance variations were represented with 3% ~ 5% range. If we test during more long time in outdoor environment of four seasons, these variation ranges might be expanded. Thus, real time performance check and periodic calibration for in situ radiation monitoring system might be very important procedure to improve the reliability of measuring data. Log 263. MEV PHOTON IMAGING WITH ROBOTIC SAMPLE POSITIONING AT A RESEARCH REACTOR. Hashem, N.R. (1); Haas, D.A. (1); Pryor, M.W. (1). (1) The University of Texas at Austin. We have recently developed and demonstrated an x-ray and gamma-ray radiography capability at the University of Texas at Austin using the TRIGA MARK-II research reactor. The photons from the reactor are a combination of Bremsstrahlung x-rays and gamma rays from fission and radioactive decay. The energy spectrum of the facility was analyzed with a NaI(Tl) scintillator detector. A 16-bit digital X-ray camera with a CAWO OG 16 scintillator designed for use with MeV range photons was used for radiography. A duplex wire type penetrameter was used to analyze the image unsharpness and spatial resolution of the digital radiography system. Automation of this non-destructive testing (NDT) procedure is done using a SIA5D 7-axis robotic manipulator. The robot is used for the precise positioning of samples in front of the scintillator. A robotic arm allows for the NDT operator to image objects that have larger dimensions than the detector field of view. Future work includes performing computed tomography (CT) with the robot and imaging system to create 3-dimensional representations of objects.


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Log 264. DEVELOPMENT OF SMALL-SCALE RADIOANALYTICAL PROCEDURE FOR THE SEPARATION OF U AND Pu IN ENVIRONMENTAL SAMPLES CONTAINING ULTRA-LOW LEVEL U. Macsik, Z. (1); Katona, R. (1); Stadelmann, G. (1);Varga, B. (1); Vogt, S (1). (1) Environmental Sample Laboratory, Office of Safeguards Analytical Services, Department of Safeguards, International Atomic Energy Agency. Environmental samples have been routinely analyzed at IAEA Environmental Sample Laboratory since environmental sampling was introduced in 1996 as one of a number of new IAEA safeguards measures that contribute to confirming the absence of undeclared nuclear material or nuclear activities. Environmental sampling for safeguards is mainly focused on the collection of swipe samples inside nuclear facilities. The U content of safeguards swipe samples can vary in a very wide range: from nanogram to microgram level. The standard radioanalytical procedure based on ion exchange and extraction chromatography that is applied in the bulk analysis of environmental swipe samples for safeguards purposes is able to cope with this wide range until single digit ng level. However, need for analyzing ultra-low level U samples (pg range) has been recently raised. Our standard radioanalytical procedure could not be used due to the relatively high U contribution (typically <50 pg) therefore it was modified to a smaller scale to minimize the U contribution originating from the procedure and significantly decrease the sample preparation time while ensuring robust, reproducible procedure with acceptably high U and Pu recoveries. Log 265. CONTAMINATION OF NATURAL SOILS IN NORWAY WITH Cs-137 AND Pu-239,240: RELATIVE CONTRIBUTIONS FROM ATMOSPHERIC NUCLEAR WEAPON TESTS AND THE CHERNOBYL REACTOR ACCIDENT. Steinnes, E. (1). (1) Department of Chemistry, Norwegian University of Science and Technology, Norway. Based on repeated nationwide sampling of natural surface soils the relative contribution of major nuclear events to the contamination of Norwegian territory with key radionuclides and the geographical differences in their deposition has been assessed. The geographical distribution of Cs-137 from nuclear weapons tests in the 1950s and 1960s was fairly uniform over the country but higher in areas with high annual precipitation. The contribution from the Chernobyl accident varied strongly between different areas and in some cases exceeded the contribution from the nuclear weapons tests by two orders of magnitude. Currently a major fraction of the residual Cs activity is strongly bound in the upper mineral soil. The leaching of Cs-137 from the surface soil differs between regions and is clearly influenced by the chemical composition of ambient precipitation. The current geographical distribution of Pu isotopes in the surface soil, as determined by high-resolution ICP-MS, is similar to that of the nuclear weapons Cs-137. The Pu-240/Pu-239 ratio is uniform and points to the nuclear weapons fallout as the dominant source. Log 266. RADIOCHEMICAL AND INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS USING KYOTO UNIVERSITY REACTOR. Sekimoto, S. (1); Ohtsuki, T. (1). (1) Kyoto University Research Reactor Institute, Japan. Kyoto University Research Reactor (KUR), which can be operated with 5 MW in maximum, has worked in Japan to support a lot of researchers using neutron activation analysis (NAA) for their analytical studies in various research fields. After about three years shutdown period to approve the government permission based on the new regulation standard due to the accident at Fukushima Daiichi Nuclear Power Plant in 2011, KUR will restart in May 2017, and thereby a program for the cooperative use of KUR also will open for researchers. Here, we introduce some achievable NAA program using KUR including the latest results, e.g. contents of halogen elements in the reference materials issued in Japan, USA, and so on. Radiochemical NAA (RNAA) using KUR has been recently applied to accurate determination of three halogen elements, Cl, Br and I in reference materials from U.S. Geological Survey (USGS) and Geological Survey of Japan (GSJ). Abundances of the three halogens are important for geochemical and cosmochemical discussion of mantle xenolith and meteorite samples. However, such kind of discussion is limited due to that there are few data for halogens in those samples. Among USGS reference materials subjected to RNAA, some materials maybe inhomogeneous in halogen. To investigate the heterogeneity of other elements, INAA will be performed on several aliquots of these materials. The results will be presented.


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Log 267. A STUDY ON DISTRIBUTION CHARACTERISTICS OF 137Cs IN THE MUSHROOM IN KOREA. Lee, S.H. (1); Oh, J.S. (1); Lee, J.M. (1); Lee, K.B. (1); Kwon, E.H. (1); Joo, M.H. (2). (1) KRISS. (2) Hanil Nuclear Co. 800 of mushrooms were collected nationwide for the measurement of artificial radionuclide due to increased concern about radioactive contamination after Fukushima and a representative gamma emitted radionuclide 137Cs were measured. The activity concentrations of 137Cs in mushrooms were from MDA up to 77 (Bq/kg-fresh weight) and the highest concentration of 137Cs was found Sarcodon asparatus. In most of the mushrooms investigated, less than 1 Bq/kg of 137Cs was detected, but relatively high levels of 137Cs were detected in some mushroom species (Sarcodon asparatus, Lentinula edodes, and Ramaria botrytis etc), especially in mushrooms collected from forest. Although trace amounts of 134Cs were detected in shiitake mushrooms (Lentinula edodes) produced in Jeju Island, the main origin of 137Cs in mushrooms is thought to be originated from past nuclear bomb tests conducted from 1950s to early 1960s. Log 268. ACTINIDE MOLECULAR ION FORMATION IN CORRISION REACTION CELL OF TRIPLE QUADRUPOLE ICP-MS/MS AND ITS APPLICATION TO QUANTITATIVE ACTINIDE ANALYSIS. Suzuki, T. (1); Yamamura, T. (2); Abe, C. (2); Konashi, K. (2); Shikamori, Y. (3). (1) Nagaoka University of Technology. (2) Tohoku University, Japan. (3) Agilent Technologies Japan. The quantitative actinide analysis by quadrupole ICP-MS/MS, Agilent 8900, is studied. The subject actinides were U, Np, Pu, Am, and Cm. The used nuclides were U-238, Np-237, Pu-240, Am-241, and Cm-244, respectively. Np 237 was used the daughter of Am-244. Pu-240 was used the daughter of Cm-244. The amount of nuclides are evaluated by using the alpha counting except U. U was used the standard sample for ICP-MS. We confirmed the formation percentages of ionic species of each actinides in several kinds of collision reaction cell modes, no gas, hydrogen gas, helium gas, oxygen gas, and BEC (background equivalent to counts) and LOD (limitation of detection) of each actinide ions are confirmed in each modes. And also, we investigated the formation rates of molecular ions (oxide ions and dioxide ions) in collision reaction cell of oxygen gas mode. We found that the formation rates of actinide ion, oxide ion, and dioxide ion depends on the oxygen flow rate and on actinides; the oxide ion of actinide with lower atomic number among our tested actinides is easily formed, while the dioxide ion of actinide with higher atomic number is more easily formed. Thus, we concluded that we can discriminate the isobars of these actinides by use of the differences of these actinide molecular ion formation. Log 269. RECENT ACTIVITY FOR THE DEVELOPMENT OF REFERENCE MATERIALS AND PROFICIENCY TEST MATERIALS IN KOREA. Lee, S.H. (1); Oh, J.S. (1); Lee, J.M. (1); Lee, K.B. (1); Kwon, E.H. (1). (1) KRISS. Since Fukushima nuclear power plant accident, the fear of radioactivity in the environment including food continues to exist in public. As a result, many national labs are strengthening their monitoring and measurement activities for environment and food radiation, and accordingly, there has been a continuous need for securing reliability and quality control of the radioactivity measurement values. The Korea Research Institute of Standards and Science (KRISS) have been developing the certified reference materials as well as the proficiency test materials. In addition to supplying it to Korea, KRISS conducts a proficiency test every year.


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Log 270. DIRECT ALPHA SPECTROMETRY AS A METHOD FOR ASSAYING HIGHLY RADIOACTIVE MATERIALS. Chichester, D. L. (1); Johnson, J.T. (1); Miller, B.D. (1). (1) Idaho National Laboratory. Single-crystal (sc) chemical vapor deposition (CVD) diamond semiconductor sensors have been used as alpha spectrometers to analyze thick-matrix materials with high beta radiation emission rates. Thick-matrix samples yield complicated alpha spectra but can still produce valuable, semi-quantitative information on the actinide content of samples. However, thick samples that also emit high-intensity beta radiation are problematic, producing spectra with significantly degraded spectral resolution due to pile-up effects when using slow, silicon-based sensors. The high electron-hole pair mobility of scCVD diamond semiconductors allows these sensors to operate in the presence of high-intensity beta radiation and still produce useable alpha spectra. Tests using a 0.5 mm thick scCVD diamond sensor to assay alpha emissions from high burn-up irradiated nuclear fuel show the ability to produce reasonable thick-matrix alpha spectra when the beta radiation field exceeds the alpha radiation field by up to six-orders of magnitude. Simple semi-quantitative analyses of thick matrix spectra have been used to confirm the presence of higher-energy alpha-emitting actinides (plutonium and curium) when in the presence of lower-energy alpha emitting actinides (uranium). Region-of-interest analysis and full-spectrum deconvolution analysis can be used to perform more precise determinations. This paper will report on experimental methods developed for using scCVD semiconductors for assaying thick-matrix samples and samples emitting high-intensity beta radiation. Applications will be presented including the analysis of irradiated nuclear fuel, nuclear fallout debris, and thick-samples of uranium hexafluoride. Log 271. URANIUM MEASUREMENTS AT LOW LEVELS USING PIXE TECHNIQUE. Jeskovsky, M. (1); Kaizer, J. (1); Zeman, J .(1); Povinec, P.P. (1). (1) CENTA Laboratory, Comenius University in Bratislava, Slovakia. PIXE (Particle Induced X-ray Emission) is a powerful non-destructive technique used for element identification and determination of composition across many fields of science. With some limitations, it is suitable for analysis of almost all elements in samples of a various origin. In this study, we have focused on determination of uranium by PIXE method in solid and liquid samples, using the principal L lines of its characteristic X-rays. The targets were irradiated by 3 MeV proton beam produced by Pelletron accelerator in the CENTA laboratory. Small droplets (a few µl) of liquid samples were evaporated on 2 µm Mylar backing foil, and in the case of low concentrations (below ug/g) they were also pre-concentrated by evaporation. Solid samples were placed directly in a PIXE chamber for analysis. In the case of fine powders, the samples were mixed with formvar solution and a few µl droplets were spread on the Mylar foil for preparation of thin targets. Log 272. SPALAX-NG FOR NUCLEAR TEST DETECTION: UPDATE ON DEPLOYMENT, OPERATION AND PERFORMANCES. Topin, S. (1); Cagniant, A. (1); Le Petit, G. (1); Philippe, T. (1); Delaune, O. (1); Gross, P. (1); Douysset, G. (1); Moulin, C. (1). (1) CEA/DAM Ile de France. CEA developed for many years systems that enable to detect radioactive noble gas from civilian and military nuclear activities. It leads to the patent (1999) and the industrialization (beginning of 2000’s) of the (Système de Prélèvement d’Air et de détection en Ligne Automatique des radioXénons atmosphériques) (SPALAX). After several intermediate improvements especially regarding ovens, software and plc, CEA launch in 2013 the SPALAX-New Generation project which consists especially in the use of a new adsorbent material and a new β-γ spectrometer (Si-PIN coupled with a HPGe). The evolution leads to a significative increase of the xenon production (~ factor 4) and overall sensitivity (~ factor 4 to 40 depending the isotopes) with minimum detectable concentration of about 0.3 mBq/m3 for the different Xe isotopes. This presentation aims at given an overview on deployment, operation and performances of the SPALAX-NG system.


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Log 273. STUDY ON PM10 AND PM2.5 ATMOSPHERIC PARTICULATES IN BEIJING WITH NUCLEAR ANALYTICAL TECHNIQUES. Liu, X. (1); Yao, Y. (1); Xiao, C. (1); Shi, C. (1); Tang, C. (1); Yun, W. (1); Jin, X. (1); Wang, P. (1); Ni, B. (1). (1) Nuclear Analytical Laboratory, Department of Nuclear Physics, China Institute of Atomic Energy, China. In this work GENT SFU sampler has been used to sample PM10 and PM2.5 atmospheric particulates in Xinzhen,Beijing. Nuclear analysis techniques.NAA.PIXE.XRF.have been used to analyze the content of elements such as Mg, Al, Si, P, S, Cl, K, Ca and their concentration.The mass concentration values of PM2.5, PM10 and black carbon from July 2016 to December 2017 were counted and compared with the data from the same period in 2013 to 2014.and the relationship among the three was compared. The results show that:PM10.PM2.5 and black carbon changed in different seasons ; The average concentrations of PM10 and PM2.5 in the first and fourth quarters of both sets of data were higher than the second and third quarters.The concentration values from 2016 to 2017 have dropped from the same period in 2013 to 2014, indicating a significant improvement in air quality in this area. Log 274. AGE DETERMINATION OF A CSCL RDD SOURCE FROM POST DETONATION AEROSOL ANALYSIS. Colle, J.Y. (1); Leskinen, A. (2); McLain, D. (3); van Winckel, S. (1): Wallenius, M. (1). (1) EC JRC-Karlsruhe. (2) VTT Finland. (3) ANL USA. Post detonation forensic investigation of the radioactive source material used in a Radioactive Dispersion Device (RDD) can help to identify the origin of the source and provide relevant information in terms of remediation and prevention. The age of the source can be characterised by the ratio of parent/daughter nuclides. However, the explosion and the aerosolisation of the source material could affect this ratio in the aerosols. The Joint Research Centre (JRC) of the European Commission (EC) in Karlsruhe, Germany used a dedicated facility called RADES for the parametric study of the ratio of parent/daughter nuclides (Cs/Ba) present in aerosols produced from simulated explosions of CsCl source materials of different ages. The studies were carried out using inactive CsCl and BaCl2 mixtures with increasing barium content representing for an aging Cs-137 source. RADES uses rapid laser heating of the material to form aerosols by condensation/agglomeration from the super saturated vapour produced and by expulsion from the liquid phase during the thermal transient (simulated explosion). Aerosols are collected in an impactor and characterised according their aerodynamic size, using SEM-EDX and ICP-MS. In this paper the RADES setup as well as the results of the study will be presented. Log 275. RAPID AND ACCURATE DETERMINATION OF URANIUM ISOTOPIC COMPOSITION BY LASER ABLATION MULTI-COLLECTOR INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY FOR NUCLEAR FORENSICS. Krachler, M. (1); Varga, Z. (1); Wallenius, M. (1); Mayer, K.(1). (1) EC JRC-Karlsruhe. Uranium isotopic composition is the first and most important parameter to be determined when material out of regulatory control is investigated as this "nuclear forensic signature" can give information about the intended use and origin of the material. Commonly this is performed by high resolution gamma spectrometry (HRGS). Although HRGS is fast and non-destructive method, it lacks the possibility to detect the U-236 content. Therefore, the present study aims at developing a complementary method, yet accurate and precise, for the uranium isotopic composition analysis during the first 24-hours. The applied methodology is based on laser ablation (LA) of solid samples and subsequent determination of the isotope ratios by double-focusing multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The ns-LA-system is equipped with a TV2 ablation cell and operated at a UV wavelength of 213 nm. Prior to the measurements, optimization of the laser ablation conditions (laser energy, ablation area and time, repetition rate) was performed focusing on low material consumption and highest signal intensity. A NuPlasma double-focusing MC-ICP-MS, equipped with 11 Faraday collectors and three discrete dynode electrode multipliers was used for the U isotope ratio measurements. For method development and validation, uranium powders of certified reference materials were used. The obtained results agree well with the certified values with expanded (k=2) uncertainties of < 1% for the 235U/238U ratio and of a few % for the minor U isotope ratios. Subsequently, real samples were measured to study the potential of the method in regard to the sample size and inhomogeneity.


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Log 276. SPECTROSCOPIC COMPTON IMAGING OF PROMPT GAMMA EMISSION AT THE MeV ENERGY RANGE. Chen-Mayer, H.H. (1); Turkoglu, D.J. (1); Riley, B.K. (2); Chen, H. (3); Draeger, E. (3); Polf, J.P. (3). (1) National Institute of Standards and Technology. (2) University of Kentucky. (3) University of Maryland School of Medicine. Prompt gamma activation analysis (PGAA) is a bulk elemental analysis technique using gamma rays emitted immediately following neutron capture. Spatial information about the composition within the sample could be obtained by either collimating the incident neutron beam and/or by restricting the angle subtended by the gamma ray detector plus physically scanning the sample, a time-consuming process. This work explores the novel tomographic approach to PGAA with spatial distribution. The method is adapted from a “proton beam range finder” developed for a radiotherapy clinical setting in which MeV gammas rays are imaged by coincidence measurements of Compton scattered gamma rays by multi-detector arrays, and the events are reconstructed to obtain 3D information of the origin of the gamma ray emission with millimeter resolutions. We performed preliminary measurements at the PGAA instrument at the NIST Center for Neutron Research using a Compton imaging camera made with CZT detector arrays on a series of test samples (NaCl, Ti, and wax disks) with high-energy (> 1 MeV) emission lines. The spectra collected by the multi-pixel CZT arrays were used to assess the energy resolution and sensitivity (count rate per unit mass). Tomographic reconstructions were performed on selected emission lines such as H, Ti, and Cl. The reconstructed image intensity varies linearly as a function of sample mass, and is calibrated against the sensitivity obtained from the spectral analysis. The reconstruction methods were also evaluated using the emission data generated by Monte Carlo simulations, demonstrating a simplistic 3D elemental map achievable under ideal conditions. Log 277. EVALUATION OF BERYLLIUM AND XENON ATMOSPHERIC RADIOACTIVITY TIME SERIES MEASURED AT CTBTO RADIONUCLIDE STATIONS. Plastino, W. (1); Bianchi, S. (1); Longo, A. (1); Povinec P. (2). (1) Roma Tre University, Italy. (2) Comenius University, Slovakia. Time series analysis of beryllium and xenon atmospheric data and meteorological parameters measured at CTBTO/IMS radionuclide stations have shown great variability in terms of noise structures, harmonic content, cross-correlation patterns and local Hurst exponent behaviour. This study focused on highlighting and characterising both differences and similarities expected for these radionuclides due to their different physical and chemical characteristics along with their different source terms. Detrended cross-correlation analysis of different meteorological parameters influencing the residuals time series has shown taht the parameters mostly affecting radionuclide concentrations in the air seem to be wind direction and atmospheric pressure.


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Log 278. NEW MEASUREMENTS OF URANIUM-234 DECAY CONSTANT AND GAMMA BRANCHING RATIOS. Parsons-Davis, T. (1); Faye, S. (2); Keller, C.B. (3, 4); Wimpenny, J. (1); Samperton, K. (1); Padgett, S. (1); Williams, R. (1); Thomas, K. (1); Genetti, V. (1); Monzo, E. (5); Ruddle, D. (1); Bandong, B. (1); Moody, K. (1); Knight, K. (1); Kristo, M.J. (1). (1) Lawrence Livermore National Laboratory. (2) Wadsworth Center, New York State Department of Health. (3) Berkeley Geochronology Center. (4) Dept. Earth and Planetary Science, University of California Berkeley. (5) Dept. Chemistry, University of Minnesota Duluth. The U-234 decay constant and its corresponding uncertainty are important components of U-series and U-Th dating techniques, which apply to timescales up to approx. 600,000 years ago. These chronometers are used in constructing high-resolution paleoclimate records, and Th-230/U-234 age-dating of uranium materials has been applied to nuclear forensics. The most recent alpha counting measurements of the U-234 decay constant are slightly greater than, though within uncertainty of, more recent, higher-precision values determined from 234/238 isotope ratios measured in geological samples. We have performed new direct measurements of the U-234 decay constant by low-geometry alpha counting sources of high-purity U-234. The U-234 was purified and assayed in solution using isotope dilution (ID) by multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS), and counting sources were prepared by both molecular deposition and drop-deposition methods. Preliminary results agree with half-life values previously measured by alpha counting, but appear slightly discordant with results of geological sample evaluations. The challenges and potential experimental biases are discussed. U-234 sources were also counted with a planer high-purity Ge detector to obtain better-precision measurements of key gamma branching ratios. The gamma branching ratios are important for non-destructive uranium assay and safeguards measurements. Our preliminary results agree with previous evaluated data, and offer a 5-fold reduction of uncertainty for the key 120.9 keV gamma branching ratio. Log 279. EFFECT OF THORIUM CONTENT ON URANIUM OXIDE FUEL SOLUBILITY. Björk, K.I. (1, 2); Ekberg, C. (2). (1) Thor Energy, Oslo, Norway. (2) Chalmers University of Technology, Department of Chemistry, Gothenburg, Sweden. Cladding failure, and the following contamination of the primary system, is a common cause for short but expensive shutdown periods in nuclear power reactors. One way to mitigate this is to reduce the solubility of the uranium oxide matrix. In this paper, the effect of thorium content on the solubility is investigated. All tetravalent actinides have very low solubilities but since thorium only exist in the +IV state no additional oxidation can cause an increased solubility. Thorium atoms present in the uranium oxide matrix, should, according to theory, migrate to the surface of the sample and form a protective layer of thorium dioxide. The rate of leaching of uranium from uranium oxide pellets with a content of 0%, 7%, 25% and 40% thorium oxide, respectively, was assessed. Simulations of light water reactors with fuel thus composed have indicated the feasibility of this concept from a neutronics point of view, and the same compositions are currently being irradiated in the Halden Research Reactor. Three discs of each composition were immersed in a water solution simulating reactor coolant. The water was sampled at regular intervals and the samples were analyzed using ICP-MS with respect to uranium and thorium content. The experiment was repeated at varying conditions with respect to oxygen concentration in the surrounding atmosphere and composition of the solution (e.g. addition of boric acid). An addition of 25% and 40% of thorium dioxide reduced the uranium concentration in the solution by more than an order of magnitude for almost all investigated cases. The addition of 7% thorium dioxide resulted in a reduction of 10% to 90% depending on the case.


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Log 280. ISOLATION OF STRONTIUM ISOTOPES FROM FISSION PRODUCTS IN A SOLUTION OF ENRICHED URANIUM IRRADIATED WITH THERMAL NEUTRONS. Herman, S. (1); Glover, S. (1); Connick, W. (1); Spitz, H. (1). (1) University of Cincinnati. Characterization of post detonation fission product inventory is an important forensics signature that can aid in revealing features about the design of the device as well as its composition of fissile, other radioactive, and stable materials. One of the long-lived fission products that represents an environmental and human health risk is 90Sr because it has an affinity for bone and follows the pathway of its chemical congener calcium. The presence of 90Sr in debris after a detonation represents a source of exposure for first responders, cleanup workers, and the public. Since 90Sr is a pure beta emitter, it cannot be detected or quantified using direct measurements in the presence of other fission product isotopes. Therefore, evaluating risk requires a robust, chemical method to separate strontium isotopes in a sample of debris from remaining fission products. A method was developed using Eichrom Sr resin that successfully isolated strontium isotopes (e.g., 91Sr and 92Sr) from the other short- and long-lived fission products in a sample solution of 93 percent highly enriched uranium oxide. Fission products in the sample were created by irradiating the solution with thermal neutrons from an 8.4 Ci moderated 239Pu-Be source for 70 days. After chemical separation, 91Sr and 92Sr were isolated from the sample and detected by gamma spectroscopy and Cerenkov counting. Although the neutron flux and irradiation were not sufficient to generate 90Sr in excess of detection, the method was successful in separating the short-lived strontium isotopes from the other fission products present in the sample. Log 281. DEVELOPMENT OF ICP-MS OR ICP-OES DUAL SPRAY CHAMBER FOR SWITCHABLE ANALYSIS IN ONE SAMPLE INJECTION AND ITS APPLICATION TO RADIOACTIVE MATERIAL ANALYSIS AND RELATED CHEMICAL ANALYSIS. Furukawa, M. (1, 2, 3); Ogata, H. (1); Takagai. Y. (1). (1) Fukushima University. (2) University of Tokyo. (3) PerkinElmer Japan Co., Ltd. ICP-MS and ICP-OES is one of a high-sensitive quantification methodology for inorganic elements, and it is necessary to choose an appropriate sample-introduction means for various sample states such as liquid, solid and gases. As the sample-introduction means for ICP analysis, a concentric nebulizer (for liquid), laser ablation system (for solid) and gas exchange device (GED: for gases) are well known. In addition, a gaseous hydride generation for As and Se analyses and desolvation nebulizers such as gas/liquid separator and ultra-sonic nebulizer are also known. The usage of these attachments can improve the sensitivity of the original ICP analysis and is utilized for many application fields such as environment, space and atomic energy etc. In contrast, the choosing gases introduction or gas generation type nebulizer can improve the sensitivity of a certain elements, while the analysis of other general elements needs to be left (avoided). Here, we developed the dual spray chamber for bilateral analysis between aqueous based introduction and gas based introduction (ex. gas generation type nebulizer) and it is switchable for two-ways during the sample analysis. The use of this dual chamber can comprehensively overcome the individual problems of each conventional chambers or nebulizers. In this presentation, we report that the demonstration of the simultaneous quantification for the difficult-to-simultaneously-measure nuclides and chemical species such as radioactive I-129 (long half-life time) / radioactive Sr-90 (short half-life time) and arsenic species (hydride generation mode) / natural elements (concentric nebulizer) and show the efficiency of this chamber in ICP techniques.


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Log 282. STATE-OF-THE-ART OF NEUTRON ACTIVATION ANALYSIS AT THE REACTOR IBR-2 OF JOINT INSTITUTE FOR NUCLEAR RESEARCH IN DUBNA, RUSSIA. Frontasyeva, M.V. (1); Pavlov, S.S. (1). (1) Joint Institute for Nuclear Research, Russian Federation. The history of development of neutron activation analysis in the FLNP JINR is briefly outlined. Modernization of the pneumatic system, equipped with three automatic sample changers and created NAA database to automate the measurement and processing of gamma spectra of induced activity are described. Experience in the Life Sciences and Materials Science is summarized. Examples are given of projects related to monitoring of atmospheric deposition of heavy metals, nitrogen, POPs, radionuclides and cosmic dust carried out in the framework of the United Nations Program on Long-Range Transboundary Air Pollution in Europe (UNECE ICP Vegetation); to assessment of the state of the environment in the basin of the river Nile in Egypt; project on monitoring trace elements in aquatic ecosystem in the Western Cape, South Africa (Mussel Watch Program), Examples of using NAA in combination with microscopy for tracing biotechnological process of synthesis of nanoparticles of various metals are demonstrated. Study of natural medicinal plants and search for cosmic dust in natural planchettes (Arctic and Antarctic mosses, Siberian peat bog cores, etc.) are described. Log 283. COMPARISON OF FOUR MASS SPECTROMETRIC TECHNIQUES FOR LITHIUM ISOTOPIC MEASUREMENTS. Aubert, M. (1); Buzance, G. (2); Isnard, H. (1); Longuet, L. (2); Marie, M. (1); Nonell, A. (1); Pilon, F. (2); Tabarant, M. (1); Vielle, K. (2). (1) Den – Service d’Etudes Analytiques et de Réactivité des Surfaces (SEARS), CEA, France. (2) CEA, DAM, France. Lithium has important uses in nuclear power plant today and its isotopic composition must be determined at different stages of nuclear fuel cycle. Mass spectrometric techniques give the best performances in terms of precision and accuracy for lithium isotope ratio. The objective of this study is to compare the performances of four mass spectrometric techniques: thermal ionization mass spectrometry, multicollector inductively coupled plasma mass spectrometry, glow discharge mass spectrometry and quadrupole inductively coupled plasma mass spectrometry. Firstly the study is based on pure lithium carbonate certified reference materials in order to develop and validate the analytical procedures. For each technique, inherent phenomena (mass bias or isotopic fractionation) were carefully corrected and the analytical performances were compared in terms of isobaric interferences, stability, accuracy and precision. Evaluation of uncertainties was carefully performed and the main uncertainty sources for each technique were identified. Secondly, specific analytical procedures were developed for more complex matrix samples, including dissolution and chemical purification. The chemical separation was performed by ion exchange chromatography in order to obtain a pure fraction of lithium. This procedure of purification was validated at each stage in order to prevent any isotopic fractionation during the separation and was applied to real samples with different isotopic composition. Furthermore elemental concentration on real samples was evaluated by isotope dilution technique. In the case of glow discharge mass spectrometry, isotope ratio measurements are directly performed on solid samples, and precision and accuracy obtained were compared to the other mass spectrometric techniques.


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Log 284. DEVELOPMENT OF SHIDEROPHORE CHELATE-MODIFIED POLYMER PARTICLE AND ITS APPLICATION TO REMOVAL OF URANIUM ION. Abe, M. (1); Butsugan, M. (2); Takagai, Y. (1). (1) Fukushima University, Japan. (2) Hitachi Chemical Techno Service Co., LTD. Development of uranium remover is important for industry and a plethora of reports have concerned the synthesis of such uranium remover. In contrast, only a relatively few articles have reported the use of shiderophore chelate which makes very strong complex with various metal ion. In this study, a shiderophore chelate desferrioxamine B(DFB)-modified acrylic micro-polymer (MP) resins were synthesized and uranium (VI) ion adsorption properties on the resin were determined. The polymeric particles which have different functional groups and three size regions of the micro particle (less 7, 7-12 and 45-90 .m) were used as mother material. The synthesized resin showed good adsorption ability of uranium (VI) ion in weak alkaline solution. In addition, the investigation of absorbability of 61-elements on this resin was conducted. The result showed that it can collect some metallic elements of them. The one synthesized particle, DFB-EG80 which is a series of small particle size (7.12 um) showed sufficient U(VI) absorbability(96%). In this study, the impact of pH, temp and maximum capacity was investigated. The advance-adsorbed elements were also investigated. The desorption condition was successful using HCl solution (100%). The synthesis and evaluation of the remover of uranium is presented. Log 285. SPECIATION MEASUREMENTS USING EMISSION AND ABSORPTION SPECTROSCOPY TO INVESTIGATE CONDENSATION CHEMISTRY FOR NUCLEAR FORENSICS. Koroglu, B. (1); Crowhurst, J. (1); Armstrong, M. (1); Wagnon, S. (1); Weisz, D. (1), Mehl, M. (1); Zaug, J. (1); Radousky, H. (1); Rose, T. (1). (1) Lawrence Livermore National Laboratory. The high temperature chemistry of rapidly condensing matter is under investigation using a plasma flow reactor to understand the chemical fractionation processes that occur during the rapid cooling of a low yield nuclear fireball. Tests were run using aqueous solutions of metal nitrates (e.g. uranyl nitrate). Reactants passing through the plasma torch were exposed to different cooling histories as the temperature was decreased from ~ 6,000 to 1000 K. Emission spectra between 400 and 600 nm and absorption spectra in mid-IR wavelengths were recorded to monitor the chemical evolution from atomic to di-atomic and polyatomic species. Measurements were performed as a function of distance and temperature along the reactor. We observed variations in the relative abundances of metal oxides as a function of distance along the reactor due to the differences in their volatilities. Changes in the speciation were also seen to depend on the cooling rates along the reactor. Therefore, the current study is important for understanding the role of kinetics of chemical reactions on the chemical fractionation patterns observed during the condensation of a nuclear fireball.


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Log 286. THE TRANSURANIUM ANALYTICAL LABORATORY'S SUPPORT FOR THE PRODUCTION OF TRANSCURIUM ISOTOPES DURING CAMPAIGN 77 AT THE OAK RIDGE NATIONAL LABORATORY. Delashmitt, J.S. (1); Canaan, R.D. (1); Couch, J.D. (1); Guy, V.J. (1); Meadows; H.A. (1); Partridge; J.D. (1); Roach; B.D. (1); Smith; R.R. (1); Wightman; C.M. (1). (1) Oak Ridge National Laboratory. The Radiochemical Engineering Development Center (REDC) at the Oak Ridge National Laboratory (ORNL) is the production, storage, and distribution center for the heavy-element research program of the U.S. Department of Energy. The REDC and the neighboring High Flux Isotope Reactor (HFIR) were built to produce transuranium elements for use in national and international research programs and since 1966 has been the main center of production for transcurium elements in the United States. In 2017, REDC successfully completed Campaign 77, its latest Bk-249/Cf-252/Es-254 production campaign. As final products, REDC staff hoped to recover 1 g of americium, 24 g of curium, 8 mg of 249Bk, 70 mg of 252Cf, and 1 µg of 254Es. Bk-249 product generated from recent campaigns was fabricated into a target and placed into a beam of 48Ca successfully creating super-heavy element (SHE) 117 now named Tennessine. Final products from Campaign 77 were slated to ship to researchers around the globe. The Transuranium Analytical Laboratory (TAL) provides the uniquely specialized chemical and radiochemical protocols and analyses on a wide variety of nuclear matrixes in support of these production campaigns of transcurium isotopes. Titrations, dissolutions, separations, and dilutions of high activity samples are completed in hotcells and gloveboxes in preparation for analytical radiochemistry determinations completed at the TAL in support of the REDC’s mission. A primary concern of Campaign 77 was maintaining as much Bk-249 as possible throughout the separation processes, and considering its short half-life, 320 days, Bk-249 determination hold points were established. Further, this campaign included the goal of separating and shipping a minute amount of extremely rare Es-254, also short lived with a half-life of 276 days. An overview of the Transuranium Analytical Laboratory’s support of this fast paced Campaign 77 will be presented including the quick and reliable radiochemical method developed for the determination of Bk-249 that was used throughout the purification process at key hold points to ensure the delivery of a final purified product. Log 287. RAPID ANALYSIS OF STRONTIUM-90 BY INDUCTIVELY COUPLED PLASMA QUADRUPOLE MASS-SPECTROMETRIC APPROCH. Takagai. Y. (1); Furukawa, M. (1, 2, 3). (1) Fukushima University. (2) University of Tokyo. (3) PerkinElmer Japan Co., Ltd. To do quantification of radioactive strontium-90 which is originated in Fukushima nuclear power plant accident, an analytical means based on inductively coupled plasma quadrupole mass-spectrometry (ICP-QMS) analytical technique was developed. In this presentation, the methodology based on ICP-MS techniques and the related techniques for effective quantification of Sr-90 such as the sensitivity and precision improvement means etc are presented. [1] The ICP-QMS quantification system was preceded by the comprehensive automatic chemical separation system combining an on-line solid phase extraction column separation (SPE based on lab-on-valve) and oxygen reaction in MS (designated the cascade step). The proposed system overcomes the isobaric interference of Zr-90. Even the concentration of Zr-90 exceeds that of Sr-90 by more than six orders of magnitude. In no appearance As alternative approach, the Sr-90 standard can be replaced with the stable isotope, for instance Sr-88 as a pseudo-standard. This ICP-QMS system provides the chromatographic peak as data. [2] This ICP-QMS with online SPE cannot simultaneously quantify Sr-90 with the recovery efficiency (R%) on SPE in one-shot samples. Hence, we developed the split flow line system and the system was put in the ICP-MS analysis for Sr-90. By this combination, the ICP-MS sequentially measures the quantification of Sr-90 and the R% on the SPE column. By these combinations of several techniques, the comprehensive Sr-90 analytical system based on ICP-QMS achieved 0.3 Bq/L (water). The system demonstrated the efficiency using actual sample in contaminated water in Fukushima nuclear power plant.


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Log 288. A METHOD FOR MEASURING RADIOXENON EMANATION COEFFICIENTS. Blood, M.E. (1); Bieglaski S.R. (1, 2); Haas, D.A.(1); Artnak, E.J. (1). (1) University of Texas at Austin. (2) Georgia Institute of Technology. The emanation of radioxenon is important in nuclear forensics for characterization of underground nuclear detonations detected by the International Monitoring System. Emanation has been extensively studied for radon, however these values for radioxenon are not well known. This study has developed a process for measuring the emanation of radioxenon in a laboratory. U3O8 powder is encapsulated in quartz and irradiated in a thermal flux using the University of Texas at Austin TRIGA Mark II research reactor. The activity of radioxenon is measured with a high-purity germanium detector. The quartz is then broken within an evacuated gas manifold, releasing radioxenon fission products from the powder into the piping. Gas that has escaped the power is passively captured using a cryotrap attached to the manifold system. The captured radioxenon gas is compared to the gas still remaining within the powder, by means of gamma spectroscopy. Each trial produces multiple radioisotopes of xenon, which can be quantified with spectral analysis. The emanation value among different isotopes of the same element should be relatively the same. Hence, measuring the emanation coefficient for each isotope allows for higher fidelity within a single trial, providing confidence in the experimentally measured value. Preliminary results demonstrate the capability of this new process to make emanation measurements with consistency. Log 289. MOLECULAR-FREE ANALYSIS OF U-BEARING PARTICLES WITH NAUTILUS: A NEW KIND OF MASS SPECTROMETER. Willingham, D. (1); Groopman, E.E. (1); Grabowski, K.S. (1); Sangely, L. (2). (1) US Naval Research Laboratory. (2) International Atomic Energy Agency. We demonstrate use of the Naval Ultra-Trace Isotope Laboratory’s Universal Spectrometer (NAUTILUS) at the U.S. Naval Research Laboratory to measure 236U directly from U-bearing particles without molecular isobaric interferences. Secondary Ion Mass Spectrometry (SIMS) is one of the primary tools used by the Safeguards community for analysis of U-bearing particles collected from Safeguards inspections. Along with the major U-isotopes and 234U, the minor isotope 236U is of interest because it is an indication for the presence in the sample of uranium reprocessed from spent nuclear fuel. The identification of 236U-containing particles is complicated due to the presence of molecular isobaric interferences. The molecule 235U1H is problematic at mass 236, since a mass resolving power >38,000 is required to separate 235U1H from 236U. NAUTILUS is a combination of SIMS and a single-state accelerator mass spectrometer. This configuration breaks molecules apart using a stripping gas following the accelerator stage of the mass spectrometer, allowing for the rapid screening of U-bearing particles with greater selectivity than traditional SIMS analysis. Molecular-free images acquired from particle samples of NIST CRMs U850, U500, and U030A, each with an addition of monazite particles (containing percent levels of natural uranium) identified only particles containing 236U, whereas corollary SIMS images were prone to false positive identifications of 235U1H from the monazite particles. Additionally, we show preliminary results on molecular-free measurements from individual U-oxide particles over a range of 0.1 to 60 ppm 236U by weight, representing some of the main challenges in SIMS measurements for Safeguards purposes.


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Log 290. NAUTILUS: A NEW KIND OF MASS SPECTROMETER. Willingham, D. (1); Groopman, E.E. (1); Grabowski, K.S. (1). (1) US Naval Research Laboratory. The Naval Ultra-Trace Isotope Laboratory’s Universal Spectrometer (NAUTILUS) developed at the U.S. Naval Research Laboratory combines the best attributes of Secondary Ion Mass Spectrometry (SIMS) and Single-Stage Accelerator Mass Spectrometry (SSAMS). NAUTILUS has a SIMS front-end capable of high-resolution ion imaging and high precision isotope ratio measurements combined with a SSAMS back-end well suited for dissociating molecular isobaric interferences. Unlike other SSAMS-based analytical tools, NAUTILUS measures positive ions including rare earth elements (REEs) and actinides of interest to nuclear materials analyses. We demonstrate the utility of this capability using two separate use cases. The first aimed at eliminating the 235U1H molecular interference on 236U prevalent in the analysis of U-bearing particles from cotton swipes for Safeguards inspections. In our study, we measured several NIST CRMs (U850, U500 and U030A) in the presence of monazite containing a few weight percent of natural uranium. The 236U in these standards range from 3000 to 6 ppm. The second aimed at measuring isotope depletions in 149Sm, 151Eu, 155Gd, and 157Gd obscured by a large molecular background from a sample from reactor zone (RZ) 13 of the Oklo natural nuclear reactor. Due to its complex composition, there are a number of molecular isobar interferences in regions of interest for the primary U-bearing minerals, and secondary rare-earth-aluminous phosphates and galenas that otherwise cannot be resolved. The ability to measure REEs from such a complex sample may provide insights into the utility of NAUTILUS to analyze of other complex materials such as nuclear fallout debris. Log 291. NEW DEVELOPMENTS IN RESONANCE IONIZATION MASS SPECTROMETRY FOR URANIUM AND PLUTONIUM ISOTOPIC ANALYSIS. Savina, M. (1); Isselhardt, B. (1), Trappitsch, R. (1). (1) Lawrence Livermore National Laboratory. Resonance Ionization Mass Spectrometry (RIMS) is a laser-based form of mass spectrometry that provides a high-efficiency means of obtaining actinide isotopic compositions of solids without sample preparation. While RIMS has been practiced since the 1970s, we have recently developed improved methods specifically for actinide analysis that provide discrimination against isobaric interference, resolution of unavoidable interferences (in the case of simultaneous multi-element analysis) and very high detection efficiency. We have also developed simplified techniques that reduce the complexity and cost of the analysis while improving reliability. In this talk we discuss the basic science behind RIMS, and the application of laser spectroscopy to develop new RIMS methods. We evaluate and compare several laser spectroscopic schemes for uranium and plutonium in terms of efficiency and discrimination against isobars. We discuss their utility in characterizing actinide, mixed-actinide, and mixed actinide / non-actinide samples. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. This work was supported by the National Nuclear Security Agency Office of Defense Nuclear Nonproliferation Research and Development, and by the Defense Threat Reduction Agency through award no. HDTRA 135636-M. LLNL-ABS-743184


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Log 292. DEVELOPING A METHOD FOR GROSS ALPHA AND BETA COUNTING OF HIGH-PURITY MINERALS PROCESSING SOLIDS. Anvia, M. (1); Brown, S.A. (1). (1) ANSTO Minerals. Australia. Gross alpha and beta counting is a radioanalytical technique which is most often used as a screening tool for the radiological characterisation of water samples from the fields of radioecology, environmental monitoring and industrial applications. To a lesser extent, the technique is also used to measure the total alpha and beta content in soil and sediment samples. The main advantage of gross alpha and beta counting is that it is a relatively low cost and simple technique. Recently, the mining industry has shown interest in developing the tool as the first step in the radiological characterisation of high-purity minerals processing solids (final products). Only samples which are found to contain gross alpha and beta activities above a threshold value will require further radiological characterisation, therefore significantly reducing analytical costs to the company. As these high purity products are sold to clients with strict limits on the radioactivity content, the technique must be highly sensitive and precise. This semi-quantitative approach to gross alpha and beta counting for high-purity solids from the minerals processing industry is both novel and complicated. We discuss the development of a method which is suitable for this application. Log 293. NEW MORPHOLOGICAL REFERENCE MATERIALS FOR SPECIAL NUCLEAR MATERIALS. Goldberg, M. (1); Essex, R. (2). (1) Noblis. (2) NIST. Morphological characteristics of materials, such as the shape and size distribution of particles or the grain orientation and elongation of an alloy, are physical features that capture significant aspects of the processing history of a material. These features are typically highly reproducible and derive from the unique combination of equipment, chemical conditions, and engineering protocol employed in producing the material. As such, these features can assist nuclear forensic efforts in identifying the origin of a special nuclear material (SNM). Currently, there is a need for morphological reference materials to calibrate instruments, verify measurement accuracy, and enable exchange of comparable information among researchers as they identify material processing signatures. An inter-agency group of scientists and metrologists (including staff from US National Institute of Standards and Technology and the US Department of Homeland Security's National Technical Nuclear Forensics Center) is establishing criteria for the new reference materials. General characteristics of a morphology reference material such as size distribution, uniformity of shape, and resistance to atmospheric oxidation or alteration are considered along with characteristics more specifically relevant to SNM such as high density, high atomic number, and the specific particle shapes and sizes of U and Pu oxides. This presentation will summarize current thoughts and challenges in developing a suitable morphological reference material. Log 294. A CASE STUDY IN PLUTONIUM RADIOCHRONOMETRY USING MULTIPLE ISOTOPE SYSTEMS. Gaffney, A.M. (1); Wimpenny, J.B.N. (1); Parsons-Davis, T. (1); Williams, R.W. (1); Torres, R.A. (1); Chung, B.W. (1). (1) Lawrence Livermore National Laboratory. The multiple isotope decay series of plutonium enable detailed forensic interpretations of the timing of and processes involved in plutonium metal production. Radiochronometry analyses of two samples of Pu metal were performed using the 237Np-241Am-241Pu, and 234,235,236U-238,239,240Pu decay series. Uranium, americium and plutonium analyses were performed by isotope-dilution MC-ICP-MS. 238Pu was analyzed by alpha-spectrometry, and Np concentrations were determined by MC-ICP-MS with an external sensitivity calibration and radiochemical tracing using 239Np. For one sample, all measured radiochronometers yield concordant model dates in 1959-1960. The concordant model dates indicate that the method used to produce this Pu metal sample effectively removed U, Am and Np decay products from the bulk Pu. The second sample yields discordant model dates that are also older than the known production date. The isotopic composition of excess uranium in this sample is consistent with a mixture of natural uranium and uranium that was produced by radioactive decay of plutonium. The sample contains approximately 200 ppm excess 241Am, and approximately 26 ppm excess 237Np. The excess U, Am and Np present in the sample indicate that the bulk Pu was not highly purified of decay products at the time that the metal was produced. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-742962


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Log 295. PRECISE MEASUREMENT OF SUB-FEMTOGRAM QUANTITIES OF 238Pu BY THERMAL IONIZATION MASS SPECTROMETRY. Maassen, J. (1); Steiner, R. (1); Inglis, J. (1); Kara, A. (1); Lopez, D. (1). (1) Los Alamos National Laboratory. 238Pu is one of several isotopes of plutonium formed by neutron irradiation of uranium in a nuclear reactor. Accurate measurement of 238Pu is of particular importance within the field of environmental sample analysis because: (1) the parent daughter ratio of 238Pu/234U can be used in chronological studies. (2) The isotopic composition of the minor isotopes of plutonium, including 238Pu, can provide important information about the neutron energy spectra, flux and initial 235U enrichment of the reactor in which the plutonium was produced. Therefore, 238Pu represents an important fingerprint isotope for radioactive source identification. Recent commercial improvements in both TIMS and ICP-MS mass spectrometry techniques have made it possible to measure the isotopic composition of ultra-trace amounts of plutonium, but 238Pu measurements at these ultra-low sample levels remain extremely challenging because of the ubiquitous presence of 238U as an isobaric interference. This presentation describes recent improvements to sample preparation, loading and TIMS multiple ion counting techniques at Los Alamos National Laboratory, which have eliminated the problem of uranium interferences in plutonium analyses. Using this technique, we have accurately determined the 238Pu/239Pu ratio for a suite of commonly used plutonium reference materials, using a 233U tracer to monitor for any uranium contribution to the 238Pu signal. The results from 233U traced and untraced analyses indicate that our TIMS multiple ion counting total evaporation technique is capable of measuring sub-femtogram quantities of 238Pu with an external precision less than 10% (k=2). LA-UR-17-31236 Log 296. EFFECT OF IMPURITIES ON THE MORPHOLOGY OF U3O8 THROUGH XRD, SEM, AND ICP-MS ANALYSIS. Hanson, Â.B. (1); McDonald, L.W. IV (1). (1) University of Utah, Department of Civil and Environmental Engineering. It is hypothesized that the presence of impurities in uranium ore concentrates will have an effect on surface morphology. In this work, four impurities, calcium, magnesium, vanadium, and zirconium, were separately introduced to pure uranyl nitrate hexahydrate in a range of concentrations with the maximum concentration set by ASTM International's Standard Specification for Uranium Ore Concentrate. Following addition of the impurities, uranyl nitrate hexahydrate was precipitated from solution using uranyl peroxide. Incorporation of the impurity in the uranyl peroxide precipitate was evaluated using two methods. First, the concentration of each impurity in the remaining filtrate was monitored using inductively coupled plasma mass spectrometry (ICP-MS). Second, powder X-ray diffractometry (XRD) was used to measure the crystal structure of the precipitated uranyl peroxide; primarily scanning for any changes to the normal crystal structure of studtite due to incorporation of the impurities. The uranyl peroxide precipitate was then calcined to U3O8 at 800C. Scanning electron microscopy (SEM) was used to investigate morphological signatures; while p-XRD was used to evaluate the purity. To quantify any morphological differences, the Morphological Analysis for Material Attribution (MAMA) software was applied to the SEM images. Results demonstrating morphological differences based on the trace impurities will be discussed. Log 297. X-RAY SPECTROMICROSCOPY OF URANYL FLUORIDE. Ward, J.D. (1); Smiles, D.E. (2); Shuh, D.K. (2); Duffin, A.M. (1). (1) Pacific Northwest National Laboratory. (2) Lawrence Berkeley National Laboratory. Scanning transmission X-ray microscopy (STXM) is able to provide chemical information with high spatial and spectral resolution, making this technique a useful tool for chemical mapping of heterogeneous samples. As a demonstration of the utility of this technique, we apply STXM to the analysis of uranyl fluoride (UO2F2), a common byproduct of release of uranium hexafluoride (UF6) into the environment. UO2F2 is thought to convert to uranium trioxide (UO3) over time, and spectral signatures in the STXM data are consistent with these observations. This talk will touch upon best practices for sample deposition and analysis. These results demonstrate that X-ray spectromicroscopy can be a powerful complement to more traditional analysis techniques.


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Log 298. PURIFICATION OF ASTATINE BY DRY DISTILLATION UNDER OXIDATIVE CONDITIONS. Toyoshima, A. (1,2); Zhang, Z. (1); Kanda, A. (1); Ikeda, T. (1); Ichimura, S. (1); Yoshimura, T. (1); Shinohara, A. (1). (1) Osaka University, Japan. (2) Japan Atomic Energy Agency. We recently started radiochemical studies of astatine (At), which has only short-lived radioisotopes, in aqueous- and gas-phases as well as its pharmaceutical works at Osaka University. For these studies, we first need to develop a rapid preparation method of a cleanly purified At sample. In this paper, we report on our recent development of the purification of At by dry distillation under oxidative conditions. At-211 (7.2 h) was produced in the Bi-209 + He-4 reaction at Research Center of Nuclear Physics, Osaka University. The irradiated target was heated in a quartz column up to 840 °C. To yield an At oxide, mixed helium and oxygen gas was used as carrier and reactive gas, respectively, and a small amount of water was also introduced. The quarts column was connected to a 3-way valve and then Teflon tube (3-mm i.d.) which was cooled with ice water or liquid nitrogen to trap volatile At species. The trapped amount of At was continuously monitored using a CdTeZn detector. After 30-min, the trapped At was stripped with 100 micro-liter of distilled water. The radioactivity of At-211 was determined by gamma-ray spectrometry using a Ge detector. Chemical yield of At-211 was 70 - 80%. In the conference, results on ICP-MS measurement will be also presented. Log 299. HIGH-PRECISION FISSION-PRODUCT DECAY DATA DETERMINED USING MASS-SEPARATED SAMPLES COLLECTED AT CARIBU. Scielzo, N.D. (1); Kolos, K. (1), Hennessy, A.M. (2); Clark, J.A. (3); Hardy, J.C. (4); Iacob, V.E. (4); Miller, G.E. (2); Norman, E.B. (5), Park, H.-I. (4); Savard, G. (3); Shaka, A.J. (2); Stoyer, M.A. (1); Tonchev, A.P. (1). (1) Lawrence Livermore National Laboratory. (2) University of California at Irvine. (3) Argonne National Laboratory. (4) Texas A&M University. (5) University of California at Berkeley. One of the most straightforward and reliable ways to determine the number of fissions that occurred in a chain reaction is done via detection of the characteristic gamma rays emitted during the beta decay of the fission product. These gamma rays are emitted in only a fraction of the decays, and this fraction (the gamma-ray branching ratio) must be known accurately to determine the total number of fissions. The fission products Zr-95, Ce-144, and Nd-147 (along with other long-lived isotopes) play a crucial role in national-security applications. Although the level schemes of the isotopes of interest are well known, there are several challenges that arise in measuring these gamma-ray branching ratios with a fractional precision of 1%. These isotopes have Q values of less than 1.2 MeV and beta-energy spectra that peak near zero energy. The efficiencies of the beta detector and gamma-ray detector have to be well characterized and impurities and self-attenuation of the low-energy beta particle in the sample must be minimized. An approach has been developed to determine the gamma-ray branching ratios which consists of harvesting fission-product samples using low-energy mass-separated ion beams from the CARIBU facility at Argonne National Laboratory and performing beta counting using a custom-made 4-pi gas proportional counter in coincidence with gamma-ray spectroscopy using the precisely-calibrated HPGe detector at Texas A&M University. Recent measurements of the branching ratios for Zr-95, Ce-144, and Nd-147 will be presented.


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Log 300. MEASUREMENT OF RADIUM IN ENVIRONMENTAL SAMPLES THOUGH CATIONIC EXTRACTION AND ICP-MS(/MS). Dalencourt, C. (1); Michaud, A. (1); Habibi, A. (1); Leblanc, A. (1); Larivière D.(1) (1) Département de Chimie, Université Laval. Decreasing analysis time is one of the current challenges in radioanalytical chemistry, but this cannot be done at the expense of the selectivity and sensitivity. With the recent development of inductively coupled plasma tandem mass spectrometry (ICP-MS/MS), either in single or tandem mode, analytical time and detection limit could be improved. In the case of radium, its high mass and relative long half-life (1600 years for Ra-226 and 5.7 years for Ra-228) makes it a hard-to-detect element by mass spectrometry. In addition, polyatomic interferences such as barium and strontium makes its direct measurement difficult. Thus, a separation method has to be performed to preconcentrate Ra and remove alkali, alkaline earth and other elements that could generate molecular interferences. However, since alkaline earth elements (Be, Mg, Ca, Sr, Ba) have such a close chemistry to radium, a thorough separation is difficult. By improving the method presented by St-Amant et al. and by decreasing the instrumental detection limit down to 20 mBq/L (0.5 fg/g), measurement of radium on several environmental matrixes has been performed with success. Steps in method development and validation will be presented. Log 302. LASER-ABLATION ATOMIC ABSORPTION MEASUREMENTS OF LITHIUM ISOTOPE RATIOS VIA PSEUDOCONTINUUM SOURCE ATOMIC ABSORPTION SPECTROSCOPY. Merten, J.A. (1); Johnson, J.B. (1). (1) Arkansas State University. Laser ablation spectroscopies are generally considered unsuitable for isotopic measurements given the small isotope shifts in atomic transitions relative to the substantial broadening of hot, atmospheric-pressure atomic reservoirs (e.g. plasmas and flames). Furthermore, the spectroscopic resolving power/throughput tradeoff translates to minimal signal at the required resolution. As a result, Laser-Induced Breakdown spectroscopy (LIBS) results have been disappointing to date, despite the tantalizing prospect of a rapid, portable, sample prep-free measurement. Recent developments coupling laser ablation to atomic absorption and fluorescence spectroscopy have shown greater promise for isotopically resolved measurements by decoupling the spectral analysis from the thermal processes involved in laser ablation, however most implementations to date require scanning of a narrow CW laser over the course of many ablations. We present lithium isotope ratio measurements from a new laser-ablation atomic absorption technique, pseudoContinuum Source Atomic Absorption Spectroscopy (psCS-AAS), which records an entire atomic absorption spectrum at single-picometer resolution with every ablation event without probe laser scanning. We discuss experimental considerations for maximum absorption sensitivity and linearity, as well as measurements of precision and accuracy of psCS-AAS lithium isotope ratio measurements of 6Li-enriched samples. Although lithium exhibits an anomalously large isotope shift, the lessons learned here can inform more demanding measurements in uranium.


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Log 303. USING 1E13 OHM AMPLIFIER TECHNOLOGY FOR ACCURATE AND PRECISE ISOTOPE RATIO MEASUREMENTS OF LOW INTENSITY ION BEAMS. Vollstaedt, H. (1); Craig, G. (1); Lloyd, N.S. (1); Schwieters, J. (1); Bouman, C. (1). (1) Thermo Fisher Scientific. Accurate and precise isotope ratio measurements of low intensity ion beams is a prerequisite for applications in isotope geochemistry and nuclear safeguards, in particular investigating minor isotope abundances and/or isotope variations among low samples sizes. Until recently, small ion beams were measured on ion counters either in single-collector peak jumping or static multi-collection mode using a set of ion counters. However, ion counters are limited in their dynamic range and require frequent and precise determination of both their dead time and element-specific yield. Given the uncertainty on these factors, typical isotope ratio precision levels between 0.2% and 0.4% (2 SD) can be achieved. Faraday cups connected to Thermo Scientific 1E13 ohm amplifier technology overcome the limitations of sequential single collector measurements by enabling low noise 100% duty cycle static multicollector measurements of low intensity ion beams. The proven long-term gain stability of Faraday cup measurements is now extended to the ion counting regime and is overcoming significant limitations like the need of frequent and element-specific detector cross-calibration. The dynamic range of the 1E13 ohm amplifiers exceeds 30 Mcps (0.5 V on an 1E11 ohm amplifier) while the low noise levels enable static isotope ratio measurements down to precisions and accuracies of <0.1% (2 SD) at beam intensities of 30 kcps. With the newly available 3.3 pA current calibration board the gain calibration procedures are fully integrated into the electronic calibration network. Therefore, the gain factors of all amplifiers available can be calibrated conveniently by an automated software routine. Log 304. SPECTROSCOPIC STUDY ON THE MECHANISM OF EXTRACTING U(VI) FROM PERCHLORATE ACID SOLUTIONS BY HDEHDGA. Zhang, Y. (1); Yang, S. (1); Liu, Q. (1); Tian, G. (1). (1) China Institute of Atomic Energy. The separation of actinide ions by solvent extraction using multidentate acidic ligand, N,N-di(2-ethylhexyl) diglycolamic acid (HDEHDGA, HL) has recently been conducted from high acidic solutions. In order to reveal the mechanism of the extraction of actinide ions with HL as extractant, the complexation of actinide ions with N,N-dimethyldiglycomic acid (HDMDGA, HA’, a water-soluble analogue of HEDHDGA) has been investigated in aqueous solutions as well. With adding HA’ into U(VI) solution of 2 mol/L HClO4, successive formation of 1:1 and 1:2 U(VI) complexes with HA’ were observed with absorption spectral titration method. The stability constants (logβ) of the two complexes of U(VI) with HA’ are calculated, and the molar absorption spectra of the complex species are obtained from deconvolution of the spectra using Hyperquad program. Similarly, the extracted complexes of U(VI) from 2 mol/L HClO4 solution with HDEHDGA in 1,3-diisopropylbenzene have been studied. With excess of HL, 1:2 complex, UO2(HL)22+ of U(VI) is dominantly formed, and its molar absorption spectrum is very similar to that of the 1:2 complex of U(VI) with HA’, UO2(HA’)22+, in acidic aqueous solutions.


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Log 305. A STRUCTURAL AND SPECTROPHOTOMETRIC STUDY ON THE EXTRACTED SPECIES OF U(VI) BY DMDODGA. Yang, S. (1); Mao, G. (1); Zhang, Y. (1); Liu, Q. (1); Tian, G. (1). (1) China Institute of Atomic Energy. Unsymmetrical N,N-dimethyl-N,N-dioctyldiglycolamide (DMDODGA) has much better extraction ability for actinide ions than its symmetrical analogues, such as N,N,NN-tetraoctyldiglycolamide (TODGA), especially for actinyl ions due to the less steric hindrance from the smallest methyl groups in the extracted complexes. The complexation of U(VI) with DMDODGA and its small molecule analogue tetramethyl-diglycolamide (TMDGA) was studied with spectrophotometry, X-ray crystallography, and extraction slope analysis. Two successive complex species, UO2(L)2+ and UO2(L)22+ (L = TMDGA or DMDODGA) were identified and their stability constants were calculated at 25. in 1.0 mol/L NaNO3 and in 1-octonol respectively. UO2(L)2(ClO4)2 (L=TMDGA) is crystallized in a monoclinic space group, P2(1)/n. The two tridentate TMDGA ligands are coplanar and each coordinates to U(VI) with three oxygen atoms in the equatorial plane. The molecule is centrosymmetric and the uranium atom is at the inversion center. The structure clearly indicates that alkyl groups bigger than methyl will increase the steric hindrance then weaken the bonding between actinyl ions and the ligands due to the limited space in the equatorial plane of the ions. The molar absorption spectra of UO2(L)22+ (L = TMDGA) in the aqueous solution and that of UO2(L)22+ (L = DMDODGA) in 1-octanol deconvoluted from spectrophotometric titrations were compared to the spectra of the extracted samples of U(VI) with DMDODGA in 1-octanol. The similarity in the spectra suggests that U(VI) in the extracted samples is also coordinated by two tridentate DMDODGA, which is consistent with the results from the slope analysis of the log(D)-log(CL) plot of solvent extraction experiments. Log 306. THE FATE OF RADIONUCLIDES IN DEEP GEOLOGICAL REPOSITORY SYSTEMS DETERMINED BY SYNCHROTRON-BASED X-RAY TECHNIQUES. Dähn, R. (1). (1) Paul Scherrer Institute, Switzerland. Synchrotron-based techniques such as X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) are powerful tools to determine uptake processes of radionuclides by mineral surfaces in heterogeneous systems. The mobility of radionuclides in potential radioactive waste repositories is mainly controlled by uptake processes on clay mineral surfaces. Therefore, argillaceous rocks are in many countries considered as potential host rock formations for a deep geological repository for radioactive waste. In Switzerland for example an approximately 180 million year old marine Opalinus Clay (OPA) sediment has been identified and selected as the first-priority host rock for the disposal of long-lived intermediate and high-level radioactive waste. The aim of this study was to understand and quantify the geochemical and physical processes that influence the mobility of the radionuclides in the geochemical environment imposed by the host rock. Bulk-XAS combined with micro-XRF/XAS/XRD was applied to gain molecular level information of the retention processes in argillaceous rocks. The investigations were complemented with bulk-XAS and wet chemistry results obtained for pure clay phases, such as montmorillonite or illite. Coupled with molecular simulations and wet chemistry experiments allow these investigations to make reliable predictions of the long-term retardation behavior of radionuclides.


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Log 307. COMPARISON OF RADIONUCLIDE CONTENTS IN FOOD AND ENVIRONMENTAL SAMPLES FROM NORTHERN EUROPE AND JAPAN. Weller, A. (1); Hori, M. (2); Shozugawa, K. (2); Steinhauser, G. (1). (1) Leibniz University Hannover. (2) The University of Tokyo. Food safety is one of the main concerns after a nuclear accident. The released radionuclides are of high risk for the human health through the uptake and incorporation with food and drinking water. In most cases, easily measureable gamma emitting radionuclides such as Cs-134, Cs-137 and I-131 are taken into account for radiation protection estimations. 'Difficult' radionuclides, such as the pure beta emitter Sr-90, are often underrepresented in the estimations. However, radiostrontium has a high fission yield with high radiotoxicological hazard and bioaccumulation potential. Various food and environmental samples from northern Europe and Japan were analyzed for gamma emitters and Sr-90. A fast and sensitive method for Sr-90 in organic samples with various incineration steps and Liquid Scintillation Counting was developed. All food samples from Europe and Japan show similar radiological levels below the regulatory limit. However, food samples within a 350 km radius around the Fukushima Daiichi NPP reveal detectable Cs-134 activities, which can be assigned due a typical Cs-134/Cs-137 ratio to the nuclear accident at the 11th March 2011. Additionally, for the first time, activities in mBq/kg range of the anthopogenic nuclides Ag-108m and Ag-110m could be determined in commercially available seafood products from Japan. Log 308. DEVELOPMENT OF MASS SPECTROMETRIC TECHNIQUE AND ITS APPLICATION TO IDENTIFY THE RADIONUCLIDE SOURCE. Lee, S.H. (1). (1) KRISS. Despite the additional contribution through Chernobyl nuclear power plant accident and Fukushima nuclear NPP accident, the source of artificial radionuclide in the environment is mostly originated from atmospheric nuclear bomb tests conduct in 1950's to early 1960's. Thus, the concentrations of artificial radionuclides in the environment are extremely low, and which leads to a great deal of effort for the analysis. In recent years, the mass spectrometry that is the breakthrough in measurement equipment, has made a dramatic progress, and now it is possible to analyze extremely low-level artificial radionuclides with only a small quantity of sample. In this presentation, the development of mass spectrometric technique as well as their applications to investigate environmental processes will be introduced. Log 309. TRACING OF RADIOCESIUM SEPARATION FROM WATERS BY PIXE DETERMINATION OF STABLE CESIUM. Kaizer, J. (1); Ješkovský, M. (1); Pánik, J. (1,2); Zeman, J. (1); Povinec, P.P. (1). (1) CENTA Laboratory, Comenius University in Bratislava. (2) Institute of Medical Physics, Biophysics, Informatics and Telemedicine, Comenius University in Bratislava. Radiocesium isotopes have been introduced into the environment mainly due to anthropogenic activities such as nuclear weapon testing or as a consequence of nuclear accidents, e.g. those in Chernobyl and Fukushima. Because of its quite unique properties (fairly long half-life, very good solubility), cesium-137 has been exploited in studying of different oceanographic processes. Radiocesium, conventionally measured by .-spectrometry, is generally extracted from acidified seawater with the use of ammonium phosphomolybdate (AMP) which has great affinity for cesium cation (+1). Although the procedure typically shows very high yield (>95%), it is still usually controlled by addition of stable isotope of cesium. Concentration of cesium-133 can be measured by various techiques, e.g. inductively coupled plasma mass spectrometry (ICP-MS) being one of the more favorite methods. Here we shall present a possibility of tracing of chemical yield of radiocesium separation from waters by AMP using proton induced x-ray emission (PIXE) determination of stable cesium, developed at the CENTA Laboratory (Bratislava, Slovakia). An option for simultaneous measurements of radiocesium and stable cesium by .-spectrometry and PIXE, respectively, is discussed as well.


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Log 311. SUBSTITUENT EFFECTS ON THE RECOIL CHEMISTRY OF MO-99 PRODUCED BY THERMAL NEUTRON CAPTURE. Rosecker, V. (1, 2); Welch, J. M. (1); Weinberger; P. (1). (1) TU Wien, Institute of Applied Synthetic Chemistry. (2) TU Wien, Atominstitut, Austria. Molybdenum(IV)oxophthalocyanine (MoOPc) has been shown to be an appropriate target material for the production of recoil Mo-99 by thermal neutron capture. Therefore, substituted MoOPc derivatives were (-F, -NO2, -CH3) synthesized from the appropriate dicyanobenzenes with ammoniumheptamolybdate tetrahydrate in melt at 170C. The resulting materials were purified and characterized by IR, UV/VIS and X-ray powder diffraction. The target substances (35 - 45 mg, 0.06 mmol Mo) irradiated with 1012 neutrons per square centimeter per second in a TRIGA Mark II research reactor for 1 h. Thus activated, the samples were washed with aqueous ammonia and the ratio of the activity of Mo-99 remaining in the insoluble solids to that soluble in ammonia solution was examined by gamma spectroscopy. Attempts were made to correlated recoil yields (Mo-99 in the aqueous phase) of Mo-99 with electronic substituent effects. Log 312. MOLECULE-FREE, MICRON-SCALE IMAGING AND ISOTOPICS IN HETEROGENEOUS OKLO REACTOR MATERIAL. Groopman, E.E. (1); Willingham, D.G. (1); Meshik, A.P. (2); Pravdivtseva, O.V. (2); Grabowski, K.S. (1). (1) U.S. Naval Research Laboratory. (2) Washington University in St. Louis. We present novel, molecule-free isotope image analyses of a sample from reactor zone (RZ) 13 of the Oklo natural nuclear reactor using the Naval Ultra-Trace Isotope Laboratory’s Universal Spectrometer (NAUTILUS) at the U.S. Naval Research Laboratory. Oklo RZs, which underwent cyclical pulsed fission reaction ~2Ga ago, provide analogs for the study of long term nuclear waste. Local thermal and volcanic activity, and intrusion of groundwater have altered the samples since fission ceased, resulting the creation of secondary minerals and loss of fission products. Significant heterogeneity is present at the micron-to-hundreds-of-microns scale. Due to its complex composition, copious molecular isobars interfere with masses of interest in the primary U-bearing minerals, and in secondary rare-earth-aluminous phosphates and galenas. Isotopes Sm-149, Eu-151, Gd-155, and Gd-157 with large neutron capture cross sections are depleted, but their analyses are usually obscured by a large molecular background. NAUTILUS combines the spatial resolution of secondary ion mass spectrometry (SIMS) with a single-stage accelerator mass spectrometer that dissociates molecular isobars with a stripping gas. We directly measure atomic ions from individual SIMS microprobe spots or as raster images without loss of spatial resolution. Our sample of Oklo from RZ 13 contains some of the most isotopically depleted U found in nature, with U-235/U-238 = 0.00387 +/- 0.00002 (2sd). Sm-149/Sm-147 and Eu-151/Eu-153 ratios were found to be 0.0050 +/- 0.00016 (2sd) and 0.261 +/- 0.006 (2sd), respectively, roughly 15% and 8% lower than previous measurements from RZ 13.


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Log 313. DEVELOPMENT OF A CHARACTERIZATION CONCEPT AND CLEARANCE PROCEDURE FOR RADIOACTIVELY CONTAMINATED MERCURY WASTES FROM THE DECOMMISSIONING OF NUCLEAR FACILITIES. Klaß, L. (1); Ritz, P. (1); Shcherbina, N. (1); Wilden, A. (1); Modolo, G. (1); Bosbach, D. (1); Hirsch, M. (2); Kettler, J. (2); Havenith, A. (2). (1) Forschungszentrum Jülich GmbH. (2) Aachen Institute for Nuclear Training. During the decommissioning of nuclear facilities, certain problematic waste streams arise, e.g. contaminated or activated metals for which standard disposal concepts are not applicable. In Jülich Research Center for example, about 600 kg of radioactively contaminated mercury, formerly used as sealant material in hot cell facilities, were collected. A disposal concept for such wastes is currently being developed in the framework of the German national research project PROMETEUS (PROcess of radioactive MErcury Treatment under EU Safety-standards). Objectives are the characterization of existing radioactive mercury wastes and the separation of radionuclides from mercury, followed by a clearance procedure for mercury and a solidification and immobilization of the radioactive residues. Radiological characterization of mercury is challenging due to its high density and therefore a focus of the presented work lies on the development of a comprehensive radiological characterization concept applying alpha and gamma spectrometry as well as liquid scintillation counting. For this purpose, a separation between the different radionuclides is performed to allow the quantitative analysis of alpha emitters. The characterization further includes the development and validation of a gamma-spectrometric measurement setup which is also suitable for clearance measurements. A special gamma detector arrangement with two detectors was set up that enables a simultaneous measurement of mercury samples from opposite directions. The self-absorption of the samples due to their high density is thus minimized and the efficiency of the measurements is increased. Inhomogeneous radionuclide distributions in the samples can be determined and corrections of gamma-gamma coincidence are possible with this setup. Log 314. A NEW NEUTRON DEPTH PROFILING FACILITY AT THE HEINZ MAIER-LEIBNITZ ZENTRUM. Werner, L. (1); Trunk, M. (1); Märkisch, B. (1), Gernhäuser, R.(1); Gilles, R. (2); Revay, Zs. (2). (1) Physics department, Technical University of Munich. (2) Heinz Maier-Leibnitz Zentrum, Technical University Munich, Germany. A new neutron depth profiling (NDP) instrument was developed, set up and is currently being commissioned at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching. The elliptically tapered neutron guide provides a focal spot of about 5x5 mm² at a high flux of 3x1010 neutrons per second and cm². This unique experimental conditions require extremely careful construction of the collimation system and shielding. For the development and design of the new facility, systematic studies have been performed on the beam properties, the background, and the resolution. Samples with different thicknesses as well as chemical and isotopic compositions have been characterized. Isotopes, like He-3, B-10 Li-6 and N-14 enabled the exploration of the full energy and depth range of NDP. The new setup will be presented with a focus on its specially developed position sensitive silicon microstrip detection system optimized for highest rates and resolutions.


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Log 315. DETERMINATION OF Th-232 AND PROGENY IN BIOLOGICAL RETICULOENDOTHELIAL SAMPLES USING EMULSION AUTORADIOGRAPHIC MICRODOSIMETRY OF ALPHA PARTICLE TRACK DISTRIBUTION FROM THOROTRAST AS A SURROGATE FOR HIGH-RESOLUTION GAMMA SPECTROMETRY OF Pb-212-TRASTUZUMAB IN MICE AND ORTHOTOPIC PROSTATE TUMORS. Schneider, N.R. (1); Xie, T. (1); Sandwall, P. (1); Glover, S.E. (1); Spitz, H.B. (1). (1) University of Cincinnati. The radiopharmaceutical 212Pb conjugated Trastuzumab has been previously shown to accumulate in the liver, kidney, and spleen. Vascular microdosimetry calculations by Monte Carlo simulation painted details of the alpha energy deposition sites within the outer blood vessel walls. MCNP simulations individually evaluated five types of blood vessels within the measured organs; findings suggest alpha-particle deposition being range-limited to these blood vessel walls, not organ tissue. While targeted alpha therapy has the advantage of delivering a therapeutic dose to individual cancer cells while reducing the dose to normal tissues; this study shows internal alpha emission leads to apoptosis with a dosimetric concern of where the final alpha-particle deposition occurs. This study investigated 232Th and progenies in reticuloendothelial biological samples using emulsion autoradiographic microdosimetry of alpha-particle track distribution from Thorotrast as a surrogate for high-resolution gamma spectrometry from 212Pb-Trastuzumab. Properties of alpha-particle radiation such as direct ionization, oxygen independency, high linear energy transfer, short half-lives, and minimal depth of penetration are promising in the treatment of cancer, especially in microdosimetry. This modified, low cost, autoradiographic method uses 232Th and progeny decays occurring within the specimen to both locate and quantify individual alpha-particle origins. Alpha-particle track lengths were measured with conventional Ilford Pan F Plus 135-36, Black & White, 35mm, ISO 50 film in direct contact with human liver, kidney, and heart tissues and may be used to derive the confounding alpha-microdosimetry and pharmacokinetics between organ and blood vessel walls. Log 316. AMORE: ARGONNE MOLYBDENUM RESEARCH EXPERIMENT FOR FISSION PRODUCT MO-99. Youker, A.J. (1); Chemerisov, S.D. (1); Kalensky, M. (1); Rotsch, D.A. (1); Tkac, P. (1); Brossard, T. (1); Krebs, J.F. (1); Gromov, R. (1); Bailey, J. (1); Byrnes, J.P. (1); Quigley, K.J. (1); Jonah, C. (1); Alford, K. (1); Wesolowski, K. (1); Vandegrift, G.F. (1). (1) Argonne National Laboratory. Argonne is funded by the National Nuclear Security Administration's Materials, Management, and Minimization program to accelerate the US production of fission molybdenum-99 using low enriched uranium (LEU <20% U-235). Mo-99's decay product, Tc-99m, is used in approximately 80% of all diagnostic nuclear medicine procedures; however, there are currently no US Mo-99 producers. The AMORE demonstration uses an aqueous LEU solution as uranyl sulfate, a tantalum (phase 1) or depleted uranium (phase 2) target, and an electron linac to produce fission-product Mo-99. Phase 1 experiments produced up to 2 Ci Mo-99 at end of irradiation, and phase 2 experiments can produce up to 20 Ci Mo-99 at end of irradiation. At the end of irradiation, the irradiated uranyl sulfate solution is passed through a titania column housed in a glovebox to recover Mo from the solution, where a recovery and sampling system with 172 solenoid valves is operated remotely using LabView software. The Mo-99 product is sent directly to a hot cell where it is passed through a second titania column for further purification and to concentrate the product for entry into the LEU Modified Cintichem for final purification. Additionally, all gases are collected and decay stored, and the AMORE system uses a catalytic recombiner to recombine the hydrogen and oxygen that are generated due to radiolysis. Results from the phase 1 experiments will be discussed briefly, but the main focus will be on modifications made to the phase 2 experiments as well as the phase 2 results obtained to date.


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Log 317. FIRST MATERIAL SCIENCE APPLICATIONS AT THE NEW NEUTRON DEPTH PROFILING INSTRUMENT AT THE PGAA BEAMLINE OF HEINZ MAIER-LEIBNITZ ZENTRUM, GARCHING, GERMANY. Trunk, M. (1); Gernhäuser, R. (2); Märkisch, B. (1); Revay, Zs. (3); Werner, L. (1); Gasteiger, H. (4); Wetjen, M. (4); Gilles, R. (3). (1) Chair of Particles at Low Energies, Technical University Munich. (2) Central Technology Lab, Technical University Munich. (3) Heinz Maier-Leibnitz Zentrum, Technical University Munich. (4) Chair of Technical Electrochemistry, Technical University Munich, Germany. The recent development of lithium-based energy systems opens a new branch for Neutron Depth Profiling (NDP), which is a high resolution and non-destructive nuclear analytical technique. The in situ and in operando NDP study of lithium migration and intercalation during charging and discharging requires a high neutron flux and an efficient detector system. A novel NDP facility has recently been designed and is to be installed at the PGAA beamline at MLZ which enables the irradiation using neutron fluxes of up to 3E10cm-2s-1, as well as NDP and PGAA measurements simultaneously. We present element distribution measurements in waveguide materials, as well as the study of the ex-situ solid-electrolyte-interface (SEI) aggregation on silicon-graphite-based anodes for lithium-ion batteries. Log 318. SENSITIVITY OF SEDENTARY BIVALVES MOLLUSCS TO DIFFERENT ELEMENT IN THE INDUSTRIAL PORT OF SALDANHA BAY, SOUTH AFRICA, STUDIED BY EPITHERMAL NEUTRON ACTIVATION ANALYSIS. Bezuidenhout, J. (1); Frontasyeva, M.V. (2); Nekhoroshkov P.S. (2). (1) Stellenbosch University, South Africa. (2) Joint Institute for Nuclear Research, Dubna, Russian Federation. Mediterranean mussels (Mytilus galloprovincialis), Pacific oysters (Crassostrea gigas) and Cape mussels (Choromytilus meridionalis) were used as sentinel biomonitors of pollution by inorganic contaminants in Saldanha Bay, South Africa. The analytical technique of NAA allowed for determination of concentrations of 33 major and trace elements including heavy metals and arsenic in the soft tissues of the molluscs. These elemental results were compared in order to assessment the sensitivity of these species for the various contaminates. In general, the mussels demonstrated higher sensitivity to Ar, Cs, Se, Br and Zn than the Pacific oysters. While the Pacific oysters showed higher sensitivity to Fe and Cu. Interspecies differences were also found between the mussels, with the Cape mussels being more sensitive to Ar and Cs and the Mediterranean mussels being more sensitive to Se. It was concluded that all the bivalve mollusks present themselves as effective biomonitors but that sensitivity for the certain elements can be amplified by specie selection. Log 319. SAMPLE PREPARATION AND MASS SPECTROMETRIC METHODS FOR BIOMONITORING OF NATURALLY AND NON-NATURALLY OCCURING ACTINIDES IN THE ENVIRONMENT. Widom, E. (1); Kuentz, D.C. (1); Conte, E.R. (1); McHugh, K.C. (1). (1) Department of Geology and Environmental Earth Science, Miami University. Our research group has been evaluating the utility of lichen, tree bark, and tree rings to trace the presence and source of actinides in the environment. Sample preparation and thermal ionization mass spectrometric methods for analysis of these biomonitors will be presented, along with results from two case studies in southwest Ohio: the former Fernald Feed Materials Production Center (FFMPC), which is known for widespread airborne dispersal of uranium dust; and the former Miamisburg Mound Laboratories site (MML), for which only local, on-site contamination of plutonium and minor 230-thorium has been previously documented (the possible on-site presence of depleted uranium has been uncertain). Our results demonstrate that tree bark and lichen are both reliable long-term archives for environmental actinide contamination, and that they retain information about the nature, extent and source of contamination. Lichen from the MML provide the first evidence for the presence of off-site contamination, with anthropogenic contributions of thorium and uranium; plutonium analysis is planned. The results of the FFMPC and MML studies suggest that lichen and tree bark are highly sensitive biomonitors that can record contamination not detected by conventional survey methods. As such, these techniques can be used to constrain background environmental actinide concentrations as well as both 'stealth' and catastrophic anthropogenic releases of actinides to the environment. Furthermore, tree bark (and presumably lichen) can serve as long-term particle traps from which single particles could be extracted for analysis.


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Log 320. USING SAPROPHYTIC FUNGI FOR THE SHORT-TO-MID-TERM STABILIZATION OF RADIONUCLIDES IN SOIL. Steinhauser, G. (1); Schulz, W. (1); Gupta, D.K. (1); Groomann, S. (2); Kothe, E. (3); Wollenberg, A. (4); Gunther, A. (4); Raff, J. (4); Dubchak, S. (5); Walther, C. (1). (1) Leibniz University Hannover. (2) VKTA. (3) Friedrich Schiller University of Jena. (4) HZDR. (5) SEAPGEM. In this study, we investigate the use of saprophytic fungi to prevent uptake of radionuclides (especially Cs-137 and Sr-90) into crops (potatoes and winter rye). We report the results of our ongoing experiments with two fungal species (Schizophyllum commune and Leucoagaricus naucinus) under lab conditions as well as our field experiments in the Chernobyl exclusion zone. Log 321. EVALUATION OF MICROBIAL COMMUNITY STRUCTURE AND FUNCTIONS AS INDICATORS OF ECOSYSTEM HEALTH AND PROCESSES IN URANIFEROUS SOILS OF THE SAVANNAH RIVER SITE (SRS), USA. Chauhan, A. (1); Pathak, A. (1); Jaswal, R. (1); Ibeanusi, V. (1); Jagoe, C. (1); Seaman, J. (2). (1) Environmental Biotechnology and Genomics Laboratory, Florida A&M University. (2) Savannah River Ecology Laboratory, University of Georgia. Savannah River Site (SRS), an approximately 800 km² U.S. Department of Energy (DOE) managed ecosystem located on the northeast bank of the Savannah River (South Carolina, USA) remains historically co-contaminated by organics, heavy metals and radionuclides from decades of nuclear weapons production activities. Soils were collected during a winter and summer season from the SRS Steed Pond site and analyzed for metals and bioavailability of Uranium (U) using a whole cell bioreporter bacterial strain, which led to the binning of soils into high, medium and low uranium (U) contamination levels. Nutrients along with bacterial, archaeal and fungal communities colonizing these variable U soils were analyzed which revealed that predominant bacterial, archaeal and fungal phyla mainly belonged to Proteobacteria, Acidobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Euryarchaeota, Thaumarchaeota, Crenarchaeota, Ascomycota, Basidiomycota, Glomeromycota and Microsporidia, respectively, regardless of seasons or contamination levels. When the environmental and nutrient data was correlated to the microbial data, we found that almost all the nutrients measured in the SRS soils, such as total U, bioavailable U, Ni, total carbon (TC), total phosphorus (TP), and microbial biomass carbon (MBC) correlated more with the highest contamination site, suggesting that soil biogeochemistry plays a critical role in the cycling of both U and Ni in the SRS environment. Moreover, using functional metagenomics, genes associated with several microbially-mediated functions were also identified, including carbohydrate metabolism, virulence factors, respiration, aromatic compounds metabolism, membrane transport, Cobalt-zinc-cadmium resistance, and oxidative stress-related proteins of the YgfZ family; some of these are likely facilitating bioremediation of contaminants within the SRS soils. Such comprehensive studies will facilitate a deeper understanding of heavy metal tolerance and hydrocarbon degradative mechanisms in complex, mixed contaminant habitats and provide recommendations for environmental stewardship of anthropogenically-impacted environments.


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Log 322. MICELLE-MEDIATED EXTRACTION AND NEUTRON ACTIVATION DETERMINATION OF NANOGRAM LEVELS OF VANADIUM IN SEAWEEDS. Serfor-Armah, Y. (1,2); Carboo, D. (3); Akuamoah, R.K. (3); Chatt, A. (1). (1) Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Canada. (2) Graduate School of Nuclear and Allied Sciences, University of Ghana. (3) Department of Chemistry, University of Ghana. Although micelle-mediated extraction, commonly called cloud point extraction (CPE), to preconcentrate trace elements is known, it has not been used much in combination with neutron activation analysis (NAA). A simple one-step CPE method was developed for the preconcentration of V using a mixture of PAN and TAN chelating agents and PONPE-20 surfactant. The parameters affecting the separation were optimized. The recovery of V under the optimum conditions of pH 3.7, [PAN/TAN]=1x10E-4 M, [PONPE-20]=0.1% (m/v), ionic strength=0.05 M KNO3, and a temperature of 41°C was >99%. Vanadium was assayed using the 1434.1-kev photopeak of 52-V (half-life=3.75 min) after an irradiation for 1 min at a neutron flux of 2.5x10E11 cmE-2 sE-1 in the Dalhousie University SLOWPOKE-2 reactor facility, decay for 1 min and counting for 10 min. The detection limit of the CPE method for V was 1.5 ng/g in seaweeds. The method was validated using several reference materials. Our measured values agreed very well with the certified values. It was applied to the analysis of seaweeds, and the V levels in them generally varied between <0.18 and 20 microgram/g (dry weight). Log 323. MEASUREMENT OF 131I ACTIVITY IN AIR INDOOR POLISH NUCLEAR MEDICAL HOSPITAL AS A TOOL FOR A INTERNAL DOSE ASSESSMENT. Brudecki, K. (1); Szczodry, A. (2); Mroz, T. (3); Kowalska, A. (2); Mietelski, J.W. (1). (1) Institute of Nuclear Physics, Polish Academy of Sciences, Poland. (2) Department of Endocrinology and Nuclear Medicine, Holycross Cancer Center, Poland. (3) Pedagogical University in Cracow, Poland. Currently radiological protection system for nuclear medicine medical personnel in Poland conducted only with TLD detectors, is insufficient. The system monitors only exposures to the external nuclear radiation field and should be supplemented by internal dose measurements. Studies presents the possibility of applied 131-I air activity measurements indoor nuclear medical hospitals as a tool for an internal dose assessment. 131-I air activity measurements were performed indoor the Department of Endocrinology and Nuclear Medicine Holy Cross Cancer Centre in Kielce, Poland. Iodine from the air was collected by a mobile aerosol sampler HVS-30 combined with a gas sampler. Gas and aerosol fraction was measurement. The measured gaseous fraction activities ranged from (28 ± 1) Bq m³ to (492 ± 4) Bq m.3. In each sampling sites, activity of gaseous iodine fraction trapped on activated charcoal was significantly higher than activity of aerosol fraction captured on Petrianov filter cloth. Having measured the activities in the air, an attempt has been made to estimate annual inhalation effective doses, which were found to range from 0.47 mSv to 1.3 mSv. The highest annual inhalation equivalent doses have been found for thyroid. The presented method can successfully fill the gaps in internal doses measurements among nuclear medicine medical personnel.


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Log 324. SURFACE DERIVATIZED TRANSPARENT CONDUCTIVE OXIDES: CARBON-FREE ELECTRODES FOR THE ELECTROCHEMICAL OXIDATION OF Am(III). Sheridan, M.V. (1); McLachlan, J. (1); Lopez, M.J. (1); Periero, F. (1); Dares, C.J. (1). (1) Florida International University. The selective removal of americium from used nuclear fuel (UNF) will assist in the development of a closed nuclear fuel cycle. Selective removal of Am from UNF will reduce repository size requirements and timelines as it is responsible for the majority of the long-term heat load. Our research in this area has focused on the development of electrodes to effect the electrochemical oxidation of Am(III) to Am(VI), where it exists in acidic solutions as [AmO2]2+. The bonding properties of the Am(VI) containing dioxo cation are starkly different from those of the trivalent lanthanides in solution, making the development of ligands for its selective removal a more simplified task. Initial studies included the use of a high surface area transparent conductive oxide (TCO) electrode derivatized with a covalently bound terpyridine (terpy) ligand which facilitated the oxidation of Am(III) to Am(VI) in aqueous nitric acid. We have developed new carbon free TCO electrodes which are surface modified with polyoxometalates (POMs). POMs are attractive ligands in this regard as they have a demonstrated ability to facilitate the oxidation of Am(III), and overcome many of the solution based challenges. We will discuss our results regarding the characterization of these electrodes, and the electrochemical properties in the presence of electroactive Ln, as well as Am. Log 325. DATING OF NUCLEAR FUELS USING Cm ISOTOPIC RATIOS. Guérin, N. (1); Totland, M. (1); Kazi, Z. (1); Gagné A.(1); Burrell, S. (1); Christl, M. (2). (1) Canadian Nuclear Laboratories. (2) ETH Zurich, Switzerland. Dating of nuclear fuels has become an important tool in nuclear forensics. Combined with other tests such as physical properties, isotopic composition, and impurity signatures, dating may reveal the origin of the fuel and ultimately when, where, and how the nuclear material was removed from regulatory control. The age, or time since last purification of non-irradiated fuels can be determined based on the in-growth of daughter isotopes (e.g., Th-230/U-234, Bi-214/U-234, or Pa-231/U-235). Age dating of irradiated fuel allows for determination of the time since last irradiation but is complicated by the presence of fission, activation, and decay products. This paper will present a new post-irradiation uranium dating chronometry model based on Cm isotopic ratios. The Cm isotopes Cm-245 and Cm-246 can only be formed by the neutron activation of Cm-244, therefore, a mathematical relation exists between Cm-245/Cm-246 and Cm-244/Cm-246 ratios. Utilizing this relationship, the Cm-244/Cm-246 ratio at the end of irradiation can be calculated. By knowing the actual and at origin Cm-244/Cm-246 ratios, the Bateman equation can be used to calculate the time since last irradiation. This relationship was demonstrated using irradiated U and U/Pu nuclear fuels. Cm was purified by extraction chromatography and measured by Accelerator Mass Spectrometry (AMS). The advantages of using this model is that it relies only on the analysis of isotopic ratios of a single element, thus no isotopic yield tracer is required and no environmental fractionation effects need to be considered. An application of this technique to date hot particles will be presented.


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Log 326. MEASUREMENTS OF ECITATION FUNCTION OF 96Zr(ALPHA,N)99Mo FOR ALTENATIVE PRODUCTION SOURCE OF MEDICAL RADIOISOTOPES. Hagiwara, M. (1); Yashima, H. (2); Sanami, T. (1); Yonai, S. (3). (1) High Energy Accelerator Research Organization. (2) Research Reactor Institute, Kyoto University. (3) National Institutes for Quantum and Radiological Science and Technology. 99mTc/99Mo is the most important radioisotopes used in nuclear medicine for common diagnostic imaging technologies such as single photon emission computed tomography (SPECT). After the temporary shortage of 99mTc/99Mo due to the long shutdowns of nuclear research reactors in 2009-2010, some alternate sources of 99mTc/99Mo using accelerators have been investigated for stable supply of 99mTc/99Mo. In this study, we focused on the production route of 99Mo via 96Zr(alpha, n)99Mo reaction using a low energy accelerator. In order to estimate the production yield of 99Mo, we irradiated 6 MeV/u alpha beam onto a stacked natZr target. The irradiation experiment was performed at medium energy beam line in HIMAC, National Institutes for Quantum and Radiological Science and Technology, Japan. The natZr target was composed of a dozen 15 mm x 15 mm x 0.005 mm natural zirconium foils, which contains 2.8 % of 96Zr. The natural Ti (0.005 mm) foils were inserted to the natZr target as a beam monitor. The total target thickness was thicker than the range of projectile alpha-beam to measure the beam current on the targets. After irradiation, gamma-rays were measured with a HPGe detector. The production rates of 99Mo in natZr samples are determined by a gamma-ray spectroscopy. The excitation function of 96Zr(alpha,n)99Mo was deduced from the production rates of 99Mo by taking into account the abundance of 96Zr in the natZr target and the projectile energies on each natZr foil degraded in the stacked target. In this conference, we will present these experimental data, combined with other experimental data and calculations. Log 327. INDUCTION OF CHANGES IN THE CRYSTAL STRUCTURE OF A TERBIUM COMPOUND BY PICOMOLAR TRACES OF AMERICIUM. Steinhauser, G. (1); Welch, J.M. (2); Mueller, D. (2); Knoll, C. (2); Wilkovitsch, M. (2); Giester, G. (3); Ofner, J. (2); Lendl, B. (2); Weinberger, P.(2). (1) Leibniz University Hannover. (2) TU Wien. (3) University of Vienna, Austria. The chemical behavior and appearance of a compound is usually determined by the macroscopic constituents of the compound, not by trace impurities. In this study, we present an unusual case of a terbium azobis(tetrazolide) compound (a member of the heavy rare earth elements) that changes its crystal structure and spectroscopic properties to behave like a light rare earth element by spiking with ultra-traces of americium to the mother liquor. The traces of americium thereby change the coordination mode of the central ion and cause the Tb compound to adopt a crystal structure of the light lanthanides prior to the so-called 'gadolinium break'.


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Log 329. RADIOANALYTICAL CHARACTERIZATION OF FLY ASH MODIFIED BY CEMENT AND ITS VALORIZATION AS ADSORBENT FOR AS(V) REMOVAL. Karanac, M. (1); Đolić, M. (2); Janković Mandića, Lj.(2); Veličković, Z. (3); Povrenović, D. (4); Pavićević, V. (4); Marinković, A. (4). (1) Innovation Center of the Faculty of Technology and Metallurgy Ltd. in Belgrade, University of Belgrade. (2) Vinča Institute of Nuclear Sciences, University of Belgrade. (3)Military Academy, Serbia. (4) Faculty of Technology and Metallurgy, University of Belgrade, Serbia. The presence of As(V) in the environment may cause adverse effects on human health. Fly ash and bottom ash are produced as by-products of coal combustion in thermal power plants (TPP). This study present the technology related to use of fly ash as effective low cost adsorbents for As(V) ions removal. Two adsorbetns, raw fly ash (FA) and one chemically activated by cement (MFA), were characterized and used in adsorption study. Granulometric, elemental analysis, determination with thorough structural and morphological characterization of FA and MFA; by using XRD, SEM, BET and FTIR techniques, were performed. The radiochemical activity were determined using gamma spectrometry and the results of natural radionuclides (40K 200±10 Bq/kg, 226Ra 60±3 Bq/kg, 232Th 25±2 Bq/kg), was below maximum permissible concentrations for the solid waste. The equilibrium adsorption data were fitted by the isotherm models Langmuir, Freundlich and Temkin. The maximum adsorption capacity of As(V) removal by MFA adsorbent calculated from Langmuir model was 25.46 mg/g, at 45 °C. Calculated thermodynamic and kinetic parameters indicated spontaneous and endothermic adsorption process. This study presents good base for potential reuse of the material by revalorisation of the exhausted sorbent as constructive material, due to the low leaching performance. Log 330. MEASUREMENTS OF THE ALPHA-INDUCED ACTIVATION CROSS SECTIONS FOR Cu. Yashima, H. (1,2,3). (1) Research Reactor Institute, Kyoto University (2) High Energy Accelerator Research Organization (3) National Institutes for Quantum and Radiological Science and Technology The decommissioning of old accelerator facilities requires activation cross section data to estimate the residual activities induced in the accelerator components. But experimental data of activation cross section are very scarce for heavy ions which were required for decommissioning of accelerator facilities such as tandem accelerator and cyclotron. We therefore irradiated a Cu target with 101.9 MeV alpha beam to obtain excitation functions of residual radionuclides in Cu, which is a main element of accelerator components. Irradiation experiment was performed at cyclotron facility (NIRS-930), National Institutes for Quantum and Radiological Science and Technology, Japan. The Cu target was composed of a stack of 15 mm x 15 mm x 0.03 mm natural Cu foils. The natural Al (0.05 mm) and Ti (0.04 mm) foils were inserted to the Cu target as a monitor. The total thickness of Cu target was thicker than the range of projectile alpha-beam. The targets were irradiated both for a shorter irradiation (15 minutes, 70 nA) and a longer irradiation (5 hours, 80 nA). After irradiation, gamma-rays were measured with a HPGe detector. The production rates of radionuclides in Cu samples are determined by a gamma-ray spectroscopy. The excitation functions of residual radionuclides in the Cu samples by taking into account the projectile energy degradation in the target are estimated. In this conference, we will present these experimental cross section data, combined with other experimental data and calculations.


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Log 331. CHARACTERISATION OF ACTINIDE BEARING HOT PARTICLES USING MICRO TO NANO FOCUSSED SYNCHROTRON TECHNIQUES. Law, G.T. W. (1, 2); Bower, W.R. (1, 2); Utsunomiya, S. (3); Mosselmans, J.F.W. (4); Quinn, P. (4); Lyon, I. (5); Fallon, C.M, (1, 2); Fuller, A.J. (1, 2); Livens, F.R. (1,2 ); Morris, K. (2,5). (1) School of Chemistry, The University of Manchester, UK. (2) Dalton Nuclear Institute, The University of Manchester, UK. (3) School of Chemistry, Kyushu University, Japan. (4) Diamond Light Source, UK. (5) School of Earth and Environment, The University of Manchester, UK. Actinide bearing hot particles can be deposited in the environment as a result of illicit activities, nuclear accidents (e.g. Chernobyl), weapons use, mining, and/or nuclear waste disposal. Recent work has also shown that Fukushima Daiichi derived actinide-bearing hot particles were deposited in Japanese soils and sediments after the 2011 Tohoku Earthquake and Tsunami. Understanding the long-term behaviour of such materials in the environment is important for understanding risk and environmental impact, and for designing remediation strategies. However, mechanistic knowledge of hot particle alteration processes, reaction products, and radionuclide speciation are limited, especially at finely resolved spatial scales. In this talk I will provide an overview of micro- to nano-focus synchrotron X-ray, electron microscopy, and SIMS characterisation of nuclear accident born hot particles isolated from the environment, where in situ alteration had occurred over timescales ranging from a few years to decades. This data will be presented alongside findings from model hot particle alteration studies; here, particles representative of nuclear fuel (ceramic UO2) were altered in sediment / flowing groundwater column systems for 1.5 years. These column systems were then embedded with a resin to allow characterisation of particle alteration mechanisms in an intact sediment matrix, using synchrotron micro-focus techniques (XRF, XAS, XRD). Select altered particle interfaces and secondary products, alongside particles from field samples, were then FIB sectioned for novel nano-focus synchrotron characterisation at the newly commissioned Diamond Light Source Beam-line I14. Results shed light on the likely stability of actinide bearing hot particles in the environment. Log 332. COMPARISON OF THE EFFECTS OF CHELATING AGENTS ON RECOVERY OF BARIUM FROM STRONTIUM RESIN. Sorcic, A.K. (1); McLain, D.R. (2). (1) Colorado State University. (2) Argonne National Laboratory. Cs-137 is of special interest to nuclear forensics investigators. Due to its 30-year half-life and emission of gamma radiation at certain known energy levels, the isotope is commonly used in industrial, research, and medical facilities. The relative abundance of commercial-grade Cs-137 suggests that investigators are more likely to encounter lost or stolen sources containing Cs-137 than any other radioactive isotope. An important part of identifying the origin of an unknown radioactive source consists of determining the age of the source. This can be accomplished by separating the Cs-137 from its daughter, Ba-137, and determining the ratio of the two. Current age-dating accuracy and precision are highly dependent on the recovery of the parent and daughter isotopes after separation. Separation of Cs-137 and Ba-137 is typically accomplished using extraction chromatography with Sr resin, after which mass spectrometry is utilized to determine the atom ratio of the two isotopes. Recovery of Ba-137 for analysis has been found to be problematic due to inconsistent chemical recoveries and the prevalence of natural Ba in laboratories. Previous work done on the age-dating of Cs-137 ceramics at ANL suggested that using a solution of 0.05 M ethylenediaminetetracetic acid (EDTA) at pH 6 promoted recovery of Ba-137 from chromatography resin, however further studies were still needed. This presentation will cover the results of a comparative study to test the effectiveness of different chelating agents, at various pH levels and concentrations, in recovering barium from Sr resin.


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Log 333. DIODE LASER ISOTOPE-RESOLVED SPECTROSCOPY OF ATOMIC BEAMS OF NATURAL URANIUM. Lebedev, V. (1); Bartlett, J.H. (1); Castro, A. (1). (1) Chemistry Division, Los Alamos National Laboratory. We present laser absorption spectroscopy of a collimated atomic beam of natural uranium using a compact and potentially fieldable device. Uranium metal is vaporized in vacuum of a few mTorr via resistive heating using a compact ‘microcrucible’ made of tantalum foil folded in an ‘origami’ fashion. Due to the small surface area of the crucible only modest electrical powers are required to reach temperatures of over 2000 °C, sufficient for generating atomic beams of natural uranium. Interrogation of the atomic beam with a tunable diode laser allows for observing and resolving both 238U and 235U isotopes, including hyperfine splitting. The advantage of using a collimated atomic beam is that the transvere velocity components are reduced, which allows for isotopic resolution due to minimal Doppler broadening. Our approach can be readily applied to isotope-resolved spectroscopy of other actinides. Log 334. RECENT ARCHAEOMETRICAL APPLICATIONS AT THE PGAA FACILITY OF THE MLZ. Stieghorst, C. (1); Révay, Zs. (1); Renisch, D. (2); Kuhnen, H.P. (3); Papajanni, K. (4); Wagner, F. (5); Gebhard, R. (6); Schmutzler, B. (7); Passchier, C.W. (8); Sürmelihindi, G. (8). (1) Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München. (2) Institut für Kernchemie, Johannes Gutenberg-Universität Mainz. (3) Institut für Vor- und Frühgeschichte, Johannes Gutenberg-Universität Mainz. (4) Verwaltung der Staatlichen Schlösser und Gärten Hessen. (5) Physik- Department, Technische Universität München. (6) Archäologische Staatssammlung München. (7) Staatliche Akademie der Bildenden Künste Stuttgart. (8) Institut für Geowissenschaften, Johannes Gutenberg-Universität Mainz; Germany. Prompt gamma activation analysis (PGAA) and neutron activation analysis (NAA) provide a low destructive and panoramic analysis of the elemental bulk composition of materials with low detection limits down to the ppmw/ppbw-range for many elements and low dependence on the sample matrix. Both methods can be used in diverse applications of archaeometry and cultural heritage research. At the PGAA facility of the Heinz Maier-Leibnitz Zentrum (MLZ) in Garching, Germany, main reasearch topics are presently (1) provenance analysis of Roman limestone, (2) reverse engineering of ancient aqueducts and (3) corrosion of archaeological iron objects. Fine white Jurassic limestone was one of the most demanded materials for prestigious buildings during the Roman period. Later in the Middle Ages these stones where often re-used in new constructions as so-called spolia. The “gate hall” of the UNESCO world heritage site Lorsch Abbey in Germany is a well-preserved Carolingian remnant and was probably built around 900 AD. We measured the elemental composition of the façade limestone with PGAA at MLZ and NAA at the Institute of Nuclear Chemistry in Mainz, Germany. This elemental fingerprint was compared with previously acquired data of five limestone deposits by multivariate methods (principle component analysis and support vector machines) to check the assumption that the material is originally from an ancient Roman quarry in France. We present the results of this provenance study in detail and give a summary of the other recent archaeometry projects and instrument developments.


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Log 335. NATIONAL NUCLEAR FORENSICS LIBRARIES: A CASE STUDY ON BENEFITS AND POSSIBILITIES FOR VERIFICATION OF SEALED RADIOACTIVE SOURCES. Vesterlund, A. (1, 2); Canaday, J. (3); Chamberlain, D.B. (3); Curry, M.R. (4); Sandström, B. (1); Schnaars, D.D. (4); Ramebäck, H. (1, 2). (1) Swedish Defence Research Agency. (2) Chalmers University of Technology. (3) Argonne National Laboratory. (4) US Department of State. National Nuclear Forensic Libraries (NNFL) are useful assets where information regarding nuclear- and other radioactive material can be stored. If radioactive material with information contained within the library is found out of regulatory control, the library can be used to identify the material and its origin. In previous work, a number of signatures which can be useful to identify sealed sources of Am-241, were investigated. To validate the measurement results, an official query concerning information about two of the Am-241 sources that were investigated previously, was sent to the U.S National Nuclear Forensics Library. The aim of this work is to show how data, obtained in a characterization of a radioactive source, can be used to search information in an NNFL to verify the history of a lost source. A second aim is to show the usefulness of an NNFL and how the NNFL can benefit from research for updates of relevant signatures and characteristics that may prove useful to verify. Log 336. SURROGATE Cf-252 NEUTRON SOURCE CREATED BY MODERATED AMBE NEUTRONS. Stooksbury, J. (1); Hertel, N. (1). (1) Georgia Tech. Cf-252 neutron sources are used extensively in nuclear engineering and dosimetric applications. The closeout of the Cf-252 Loan/Lease program has recently reduced the availability of these sources for study. AmBe sources, however, are much more common. This work shows that a Cf-252 fission spectrum can be approximated with a lead-shielded AmBe source. Creation of other desirable spectra is possible using this same strategy. A systematic technique for reaching a desired neutron spectrum is presented. Log 337. DEVELOPMENT AND UPDATE OF IN-LINE FLOW MONITORS FOR URANIUM PROCESSING OPERATIONS. McKisson, J.E. (1); Ratner, R.T. (2). (1) McKisson Consulting Services. (2) Nuclear Fuel Services, Inc. Uranium processing to fabricate specific fuel compositions requires in-line process monitoring, which continuously quantifies material flow streams. In-line process monitoring is an essential part of manufacturing operations, material accountability, and criticality safety. As feed materials have transitioned to more recycled content, monitoring requirements exceed the capabilities of original Single Channel Analyzer (SCA) monitors. The In-Line Monitor System (ILMS) was developed to respond to the more challenging monitoring requirements of material flow streams as well as meeting additional functional requirements. The ILMS offers fail-safe performance, so that any component failure results in a safe condition of the uranium materials. The ILMS monitors the concentration of U-235 in a flow stream by measuring activity in the 185-keV peak of U-235 in the presence of additional decay products. One or more sodium iodide scintillators provide input to an MCA, which accumulates spectra over short time periods. Each gamma spectra is analyzed to quantify several parameters. A central parameter test determines if the U-235 concentration in the processing line exceeds a predetermined limit. Based on the successful operation for more than four years, the initial ILMS design was upgraded to an ILMS2 unit in 2008. The ILMS2 unit included a revised MCA and a Linux-based processor, which yielded additional monitoring functions and outputs. After successfully operating numerous ILMS2 units for more than nine years, the upgrade to Version 3 is currently in development. The features, design, testing, and current status of the ILMS3 are described.


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Log 338. INTEGRATED ANGULAR DOSE COEFFICIENTS MEASURED WITH AN ANGULARLY DEPENDENT DOSIMETER. Stooksbury, J. (1); Hertel, N. (1). (1) Georgia Tech. Integrated angular dose coefficients for a variety of measured spectra were calculated by folding those spectra with new coefficients which were recently reported. These coefficients are compared to integrated doses measured using an angularly dependent dosimeter. Log 339. ON-DEMAND PRODUCTION OF PROTACTINIUM-233 FOR NUCLEAR DATING APPLICATIONS. Naperstkow, Z. (1); Armstrong, A.F. (1); Galea, R. (2); Moore, K. (2). (1) McMaster Nuclear Reactor. (2) National Research Council Canada. As one of the world's largest producers and processors of uranium, Canada is interested in developing analytical tools to characterize samples found outside of regulatory control. The 235U/231Pa isotope pair can be used as a nuclear chronometer in forensics investigations, but usually requires access to the shorter-lived protactinium tracer 233Pa (t. = 27 d) which is not currently available in Canada. The purpose of this work was to establish a domestic supply of Pa-233 that can be produced on-demand for research purposes or incident response. This was carried out in collaboration with the Ionizing Radiation Standards laboratory at the National Research Council of Canada. Protactinium-233 was produced by neutron activation of thorium compounds at the McMaster Nuclear Reactor. Several different approaches were examined to isolate the Pa-233; a process based on column extraction chromatography was chosen for future use. Because protactinium is known to irreversibly deposit on glass surfaces, a series of elution solvents and post-elution additives was screened to identify an agent that is capable of keeping Pa-233 in solution for a period of weeks or months, without recourse to the hazardous substance hydrofluoric acid. Optimization of these processes has enabled the McMaster Nuclear Reactor to produce MBq quantities of solution-stable protactinium-233 for distribution within 48 h of a request. Log 340. PRODUCTION AND CHARACTERIZATION OF A 7Be TARGET USED FOR THE MEASUREMENT OF THE 7Be(n, p)7Li REACTION CROSS SECTIONS. Maugeri E.A. (1); Heinitz S. (1); Dressler R. (1); Ulrich J. (1); Schumann D. (1). Laboratory of Radiochemistry, Paul Scherrer Institut, Switzerland. This contribution describes the production of a target obtained by implantation of 7Be into a thin aluminium disk, produced for the measurement the 7Be(n, p)7Li cross section in the energy range of interest for the Big-Bang Nucleosynthesis. The characterization of the target, performed after the neutron irradiation, in terms of implanted 7Be activities and spatial distributions, will be addressed as well.


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Log 341. ADVANCES IN ONLINE SPECTROSCOPIC MONITORING FOR APPLICATION THROUGHOUT THE NUCLEAR FUEL CYCLE. Bryan, S.A. (1); Lines, A.M. (1); Casella, A.J. (1); Nelson, G.L. (2); Bello, J.M. (3). (1) Pacific Northwest National Laboratory. (2) The College of Idaho. (3) Spectra Solutions, Inc. Nuclear energy represents one of the stronger candidates to meet the world's ever-growing energy needs. However, the nuclear fuel cycle faces many challenges; in particular improved methods for monitoring radioactive materials throughout the cycle are needed to maintain proper safeguards and ensure safe and efficient processing of materials. Development of more effective, reliable, and fast methods for monitoring radioactive materials is integral to the continued development of the nuclear fuel cycle. Our group is investigating the application of on-line, real-time spectroscopic monitoring to the analysis of radiochemical processes spanning a range of scales from the microfluidic to the industrial. With a focus in both electronic (UV-vis, NIR) and vibrational (Raman, IR) spectroscopy, our approach has numerous strengths that are well fitted to application to this field. Spectroscopic based approaches allow for fast, non-destructive analysis using robust probes capable of handling the harsh environments typical of nuclear applications. Furthermore, by utilizing multiple types of spectroscopy, our approach is capable of identifying a significant number of species that are of interest throughout the fuel cycle. This approach has been successfully applied to monitoring real and simulated legacy wastes within the Hanford waste tanks of the United States using both industrial scale solution monitoring and telescopic Raman spectroscopy. It has also been applied to monitoring simulated process streams, including radionuclides such as uranyl, within microfluidic systems while utilizing/stimulating the development of novel micro probes. Current applications focus on developing and testing lab scale systems for the real-time analysis of separations within centrifugal contactors. This paper focuses on our current progress in on-line, real time process monitoring. Applications, advances in spectroscopic technology, and advances in analytical approach will be discussed. Included in this will be overviews of successful applications within microfluidic systems as well as applications to lab scale systems within the CoDCon project, where the goal is to follow generation of a mixed U/Pu stream in real time. Additionally, our analytical approach will be discussed. This will focus on an overview of multivariate analysis and how this technique allows for accurate identification and quantification of species in conditions where traditional single variate analysis would fail. Log 342. GAMMA GAMMA COINCIDENCE IN NEUTRON ACTIVATION ANALYSIS. Drescher, A. (1); Landsberger, S. (1). (1) The University of Texas at Austin. Certain radioisotope decay schemes involve multiple transitions between metastable levels and corresponding gamma-ray emissions before reaching the ground energy state. If a source with a complex decay scheme is surrounded by two HPGe detectors, then some disintegrations will cause coincident gamma-rays to deposit their energies in both detectors. In gamma-gamma coincidence, only coincident events in the detectors are counted which occur within a timing window. In this way, background can be reduced. In complex NAA spectra resulting from geological materials (soil or rocks) the analysis of gamma-rays suffers from overlapping peaks or spectral interferences which in turn are major limiting factors in accuracy. The Nuclear Engineering Teaching Laboratory at The University of Texas at Austin has the capability to perform gamma-gamma coincidence measurements of samples irradiated in the 1.1 MW TRIGA Mark II reactor. The gamma-gamma coincidence data acquisition system utilizes an XIA Pixie-4 module which controls a coincident detection system with two high purity germanium detectors. The resulting binary files are read into a custom software package developed in-house for data analysis and visualization. We have investigated several medium- and long-lived NAA radionuclides that can be better determined using gamma-gamma coincidence. A quality assurance protocol has also been set using 226Ra and 152Eu to ascertain that the coincidence electronics are set up properly.


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Log 343. RERERENCE MATERIALS (RM) AND PERFORMANCE TESTING (PT) SAMPLES IN RADIOACTIVITY ANALYSIS: PRACTICE, CAPABILITIES, ALTERNATIVES. Taskaev, E. (1). (1) Eckert & Ziegler Analytics, Inc. Current regulatory environment and good laboratory practices require Radianalytical Laboratories to use Reference Materials (RM), Calibration standards, Laboratory QC samples, sources for daily checks of the instruments etc. and to perform analysis of Performance Testing (PT) Samples. Metrology, traceability and usage of those sources is not well defined and somewhat is a gray area. Developing a Reference Material is a long and expensive process and major National Metrology Institutes (NMI) cannot produce enough Reference Materials (RM) to satisfy industry needs. They have even less capabilities to provide PT samples. There are efforts in the industry to address shortage of RM and develop reasonable approach. One is by introducing "working reference materials" (WRM). The other is to introduce concept of a generic "reference source", characterized by 4 major parameters: uncertainty of the activity concentration, stability over time, homogeneity of activity distribution and commutability. All the variety of sources used in the laboratory practices can be considered derivatives of a reference source. It seems that laboratories should start defining parameters of the sources they need. During this process the laboratory would emphasize the parameter most important to the application and define its optimal limits. Combination of all four parameters would define the cost of manufacturing and should be optimized to provide the best outcome. Log 344. ANALYSIS OF GALAXY SERPENT III NUCLEAR FORENSIC SURROGATE DATA USING AN INTERACTIVE WEB APPLICATION BUILT FROM R-BASED OPEN SOURCE COMPONENTS. Robel, M. (1); Kehl, J. (1, 2). (1) Lawrence Livermore National Laboratory. (2) California Polytechnic State University. The Galaxy Serpent series of tabletop exercises conducted by the Nuclear Forensics International Technical Working Group (ITWG) provides a platform for analysis and evaluation of various types of datasets of nuclear forensic interest. The use of non-sensitive, non-proprietary data facilitates the broadest possible participation. The Galaxy Serpent III exercise utilized surrogate data that was designed to mimic the properties of uranium ore concentrate (UOC), commonly referred to as 'yellowcake.' Each team participating in the exercise received the same surrogate dataset and applied a range of data analysis tools and methods at their discretion. We will present the outcome of our analysis and evaluation of Galaxy Serpent III surrogate data using an interactive web application we built using open source components. The underlying analysis platform for this tool is the R statistical computing software environment. The benefit to the community of this presentation is twofold: we will share insights into the statistically based data analysis process; and we will describe the development of a general purpose web-based data analytics toolbox useful for nuclear forensics and built from open source software. LLNL-ABS-743266.


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Log 345. A REFERENCE MATERIAL FOR EVALUATION OF Cs-137 RADIOCHRONOMETRIC MEASUREMENTS. Lavelle, K.B. (1); Carney, K.P. (2); Cessna, J.T. (1); Essex, R.M. (1); Hexel, C.R. (3) (1) National Institute of Standards and Technology. (2) Idaho National Laboratory. (3) Oak Ridge National Laboratory. A new nuclear forensic reference material has been characterized as a standard for radiochronometric determination of the model purification date for Cs-137 sources. The purification date of a radioactive source is a potentially diagnostic nuclear forensic signature for determining the provenance of a radioactive material. Reference values have been measured, with a reference date of July 7, 2011, for the attributes needed to use the Cs-137/Ba-137 chronometer: the molality (nmol/g) of Cs-137 and of the radiogenic portion of Ba-137 in the material (hereafter referred to as Ba-137*). The Cs-137 molality is (0.791 +/- 0.008) nmol/g (k = 2); this value was calculated from the massic activity of Cs-137, (348 +/- 3.0) kBq (k = 2) as measured in the NIST 4π-. secondary standard ionization chamber (previously calibrated by 4π-(e+x)-.-coincidence efficiency extrapolation counting) and the evaluated half-life of Cs-137, (30.05 +/- 0.08) a. The Ba-137* molality of (1.551 +/- 0.021) nmol/g (k = 2) was measured by isotope dilution mass spectrometry, using the measured relative proportion of Ba-138 in the material to apply a correction for the Ba-137 contribution from natural barium. A model purification date of June 16, 1964 with an expanded uncertainty of 190 days (k = 2) is calculated from the certified values. This age is consistent with the date engraved on the capsule that contained the Cs-137 starting material and with a prior independent determination of the model purification date. A full discussion of the uncertainties of the reference material values is included. Log 346. MULTIVARIANT ANALYSIS OF A GLOBAL SUITE OF ALTERED AND PRISTINE URANINITES. Corcoran, L. (1); Spano, T.L. (1); Simonetti, A. (1); Lewis, S.R. (1); Dorais, C. (1); Gunther, T. (1); Burns, P.C. (2). (1) Department of Civil and Environmental Engineering and Earth Science, University of Notre Dame. (2) Department of Chemistry and Biochemistry, University of Notre Dame. The chemical signature of a suite of pristine and altered uraninites representing five distinct deposit types; sandstone, intrusive pegmatite, unconformity, vein, and metamorphite have been determined. The uraninite characterization included major elements analysis by electron microprobe (EMP), minor and trace elements by laser ablation-inductively coupled mass spectrometry (LA-ICP-MS), and several isotopic signatures by MC-ICP-MS. Identification of secondary uranium phases were determined by powder X-ray diffraction (pXRD) and Raman spectroscopy. Due to the multivariant approach of this study, principal component analysis (PCA) has been employed to allow the direct comparison of the many variable types, e.g. trace element concentration and mineralogical data. PCA has allowed for the separation of pristine (> 80 wt% UO2) and altered (70 - 80 wt% UO2) uraninites based on deposit type. For example, the first principal component identifies two discrete groups for pristine intrusive pegmatites based on Y and Th abundances; in contrast, metamorphites are grouped due to variations in Ti, Zr, and K concentrations. The addition of the secondary minerals to the dataset will aid in identifying the different types of alternation processes and the associated mobility of elements. This information can be used for both nuclear forensics, i.e. provenance of an unknown sample and the behavior of major and trace elements with various types of alteration, which may provide some important insights into how derivative nuclear materials such as uranium oxide concentrate (UOC) may alter subsequent its production.


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Log 347. MAXIMIZING DETECTABILITY AND PRECISION FOR ISOTOPE RATIO DETERMINATION BY MC-ICPMS. Field, M.P. (1); Metzger, S.C. (1); Tevepaugh, K.N. (1); Ticknor, B.W. (1); Hexel, C.R. (1) Elemental Scientific. Measuring precise and accurate U and Pu isotope ratios in nuclear applications is often challenging due to very small sample quantities. In such cases, the precision of Multi-collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) isotope ratio determination is often limited by the total number of ions observed at the detector (counting statistics). Compared to conventional spray chambers (1-5% sample transport efficiency) we present a novel sample introduction system that achieves near total sample consumption and transport. Total sample consumption requires 1) data is acquired during the complete nebulization process and 2) 100% of the nebulized aerosol is transported to the plasma. The microFAST-MC and apex-Omega desolvating nebulizer (ESI, Omaha, USA) are used to yield the maximum number of ions per ng of sample on the NEPTUNE Plus MC-ICP-MS with Jet Interface (Thermo Scientific, Bremen, Germany). Software-defined sample volumes and injection flow rates are set to 220 uL and 50 uL/min, respectively, providing 4 minutes of stable signal for 500 femtograms of plutonium. The major isotopes of U were measured on 10(11) Omega amplifiers, whereas, minor isotopes of U and Pu were measured on newer 10(13) Omega amplifier technology. The final result is that accurate and precise ratios are obtained for (240)Pu/(239)Pu on 500 femtograms of CRM (082 and 126) and for 234U/238U and 235U/238U and 236U/238U on 400 picograms of CRM (183). Log 348. ANTICOINCIDENCE ANALYSIS FOR RADIOXENON DETECTION. Sivels, C.B. (1); Clarke, S.D. (1); Pozzi, S.A. (1); Prinke, A. (2); McIntyre , J. (2). (1) University of Michigan. (2) Pacific Northwest National Laboratory. Over the years, a number of beta-gamma coincidence detectors have been deployed for monitoring nuclear explosions. Due to the resolution of the plastic scintillation detectors typically used in the systems, whenever Xe-133 is present in a sample it causes interference in the calculation of the metastable isotopes (Xe-131m and Xe-133m) that are vital to the characterization of radioxenon measurements. An alternative method to quantify the metastable isotopes is to analyze the anticoindence spectrum of the plastic detector, whereby a signal is detected via beta measurement but vetoed if a simultaneous gamma signal is detected. This method decreases the interference from Xe-133 and improves the quantification of the two metastable isotopes. To determine if this new method provides better results, simulated and experimentally mixed radioxenon samples of varying activities of the metastable isotopes and Xe-133 were tested. The results of this analysis are presented and quantify improvements on measuring metastable isotopes in the presence of Xe-133 interference. Log 350. AUTOMATED CHROMATOGRAPHY FOR NUCLEAR FORENSIC. Field, M.P. (1); Metzger, S.C. (1); Tevepaugh, K.N. (1); Ticknor, B.W. (1); Kim, H. (1); Hexel, R. (1). (1) Elemental Scientific. The determination of precise isotope ratios by Multi-collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS) requires that samples be solubilized and elements of interest purified from both sample matrix and each other. We present a commercial-off-the shelf (COTS), fully-automated, offline chromatography system capable of simultaneously purifying both U and Pu from digested samples. The system is programed to perform U/Pu separations using the Oak Ridge National Laboratory (ORNL) Network of Analytical Laboratories (NWAL) chemical procedure, but can easily be adapted to execute a variety of chemical purification procedures. The fully automated chromatography system (prepFAST-MC-SR; ESI, Omaha, USA), operates at low pressure to reproducibly pack resin into discrete columns, load sample onto columns, perform desired chemistry steps, elute purified fractions and unpacks the columns. This configuration allows for single use of the resins for each sample, thereby eliminating any potential carry over between samples. The columns are packed from slurried suspensions of Eichrom's TEVA and UTEVA resins. In the ORNL configuration, sample is loaded onto two columns in series (C1 and C2), then each is washed of matrix before eluting Pu from C1 (TEVA column) and U from C2 (UTEVA column).


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Log 351. INTERLABORATORY COMPARISON FOR THE CHARACTERIZATION OF A CANDIDATE BOVINE KIDNEY REFERENCE MATERIAL. Castro, L. (1); Moreira, E.M. (1); Vasconcellos, M.B.A. (1). (1) Instituto de Pesquisas Energéticas e Nucleares, Comissão Nacional de Energia Nuclear (IPEN-CNEN/SP). Reference materials are of fundamental importance to obtain comparability and traceability in chemical measurements. In the present work, a candidate reference material of bovine kidney was prepared, according to internationally accepted requirements. The choice of this type of material was related to the fact that Brazil is one of the greatest meat producers in the world and it is estimated that, until 2020, the country will supply about 44 % of the world´s market. So, it is of utmost importance to have reference materials that could help assure the quality of the meat and meat products exported. Between and within bottle homogeneity of the material was assessed, as well as its short time and long time stability.The material was also sterilized with gamma radiation. An interlaboratory comparison was organized for the possible certification of the material, with the participation of 33 laboratories, both from Brazil and abroad.The methods employed by the different laboratories were: neutron activation analysis(INAA and k0 INAA),CV AAS, GF AAS, ICP MS, ICP OES, FA AS, TDA AAS, MP AES, ion chromatography,TXRF. From the overall evaluation of the intercomparison, using different statistical methods, it was possible to assign 9 certified values (As ,Co, Cu, Fe, K, Mg, Mn, Na, Se and Zn) and 10 indicative values( Br, Ca, Cd, Cl, Cs, Hf, Mo, P and Rb). Log 352. HIGH-PRECISION ISOTOPE RATIO MEASUREMENTS OF SPATIALLY RESOLVED REACTOR FUEL. Pollington, A.D. (1); Hanson, S.K. (1); Hague, R.K. (2). (1) Nuclear and Radiochemistry, Los Alamos National Laboratory. (2) Nuclear Nonproliferation, Trace Detection and Nuclear Forensics, Idaho National Laboratory. Spatially resolved small segments of reactor fuel from a historic power reactor were taken with a focused ion beam (FIB) to investigate the variability of neutron flux at different locations both axially and radially within a fuel rod. Segments (10x10x10 micron cubes) were dissolved and separated using ion chromatography to isolate uranium, plutonium, neptunium, americium and cesium. Due to the extremely small segment sizes it was not possible to subsample the dissolution for individual aliquots, so a method was developed for sequential separation of the elements from a single aliquot while at the same time reducing the contribution of blank actinide from the process. After separation, individual elements were analyzed for isotopic ratio by MC-ICP-MS, and for assay by isotope dilution by ICPMS or alpha-spectrometry. Results show that there is a clear difference in isotope and inter-element ratios between the center and the rim of individual slices of a fuel rod. These differences can be interpreted as possibly representing variability of neutron flux and fluence at different points within the fuel, as well as differences in neutron spectrum between the portion of the fuel closest to the moderator and that further away. These values can be used to calculate variability in burnup for fuel at different points within the reactor. Additionally, measurements of Pu-241 and Am-241 allow for the calculation of cooling ages that are in good agreement with the known operation history for this reactor, particularly given the small sample size.


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Log 353. ANALYSIS OF TREE BARK SAMPLES FOR AERIAL POLLUTION STUDIES. Santos, E.C. (1); Maihara, V.A. (1); Genezini, F.A. (1); Saiki, M. (1). (1) Instituto de Pesquisas Energeticas e Nucleares, IPEN-CNEN/SP. In the last years tree barks have been studied as biomonitors of atmospheric pollution due to its easy of sampling, wide availability and resistance to environmental variations. In the present study the analyses of Tipuana (Tipuana tipu) and Sibipiruna (Poincianella pluviosa) tree barks were performed. The tree barks were collected at different sites in the Metropolitan Region of Sao Paulo (MRSP) and in two small cities of Sao Paulo state considered as control regions. Neutron activation analysis was applied for As, Br, Ca, Cl, Co, Cr, Cs, Fe, K, La, Mg, Mn, Ni, Rb, Sb, Sc, V, and Zn determinations. The graphite furnace atomic absorption spectrometry was applied for Cd, Cu and Pb determinations. Results obtained for samples collected in different sampling sites in the MRSP presented wide variability due to the different pollutants levels that each tree was exposed to. High concentrations of Cd, Pb, Sb and Zn were obtained in barks sampled close to high vehicular traffic. Bark sample results indicated variability in the element concentrations depending on the proximity and intensity of the emission sources. Furthermore, these results indicated four possible pollutants sources, those being, vehicular plus soil resuspension, industrial, marine aerosols and the tree bark composition itself. The enrichment factor results indicated that all the elements originated from anthropic sources, with the exception of Cs. The cluster analyses indicated no significant differences between MRSP and control sites concerning characteristics of element emissions, probably due to the control regions are located in urban areas. Log 354. CARBON ISOTOPES AS TRACERS OF ORGANIC CARBON IN BALTIC SEA SEDIMENTS. Lujaniene, G. (1); Povinec, P.P. (2); Li, H.-C. (3); Jok.as, K. (4); Ma.eika, J. (4); Remeikait.-Nikien., N. (1); Malejevas, V. (1); Garnaga-Budr., G. (5); Levinskait., L. (4); Šemčuk, S. (1); Kulakauskaite, I. (1); Barisevi.i.t., R. (1); Bugaili.kyt., D. (1); Stankevi.ius, A. (5) (1) SRI Center for Physical Sciences and Technology, Vilnius, Lithuania. (2) Comenius University, Faculty of Mathematics, Physics and Informatics, Bratislava, Slovakia. (3) National Taiwan University, NTUAMS Laboratory, Taipei, Taiwan. (4) SRI Nature Research Centre, Vilnius, Lithuania. (5) EPA, Department of Marine Research, Klaipeda, Lithuania. Organic carbon sources have been assessed in the Baltic Sea sediments. Liquid extraction, chromatography (GC-FID, Restek Rxi-1ms column and GC/MS - QP2010, Rxi-5Sil MS 0.22 mm x 25 m column), mass spectrometry and stable isotope compound specific analyses (Finnigan Trace GC ultra-gas chromatograph, combined with the Thermo Finnigan Delta plus Advantage stable isotope spectrometer), as well as accelerator mass spectrometry, AMS (1.0MV HVE Tandetron AMS) have been applied during investigations. Measurements of 14C and 13C in sediments and in different classes of organic substances (humic acids, total lipid extracts and various lipid fractions), as well as concentrations of n-alkanes in bottom sediments collected during 2011-2017 in the open Baltic Sea waters were carried out to clarify their role in the formation of complicated organic carbon mixtures. In addition phosphofipid derived biomarkers were measured in samples of sediments and suspended matter in order to obtain information about microbial communities and their response to the contamination. Wide variations of biomarkers were observed in the analyzed samples while the biomarkers characteristic of methanotrophic bacteria were not detected in the samples collected at the chemical warfare agents (CWA) dumping site. These results agreed well with carbon stable isotope compound specific analyses. Thus depleted .14CTOC values found in the Gotland Deep were attributed to the leakage of dumped CWA, rich in fossil carbon. The contribution of terrestrial, marine and fossil sources as well as total petroleum hydrocarbons to organic carbon in the sediments was estimated to be 22%, 55%, 22% and 1%, respectively.


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Log 355. DESIGINING PROXY DATA FOR NUCLEAR FORENSICS LIBARIES EXERCISES: DETAILS ON THE CREATION AND IMPLEMENTATION OF THE GALAXY SERPENT 3 DATASET. Marks, N.E. (1); LaMont, S.P. (2); Borgardt, J. (3). (1) Lawrence Livermore National Laboratory. (2) Los Alamos National Laboratory. (3) Juniata College. The Galaxy Serpent virtual tabletop exercises are designed to develop various material components of a Nuclear Forensics Library capability. The third implementation, Galaxy Serpent 3, was designed to focus on uranium ore concentrate material, and to emphasize algorithm development and point-to-population comparisons. Details about the chemical and isotopic composition of uranium ore concentrates from specific vendors tend to be proprietary and business sensitive; typically this type of data cannot be shared broadly across the international community. For this reason, we sought to produce a realistic dataset resembling UOC that could be used for algorithm development activities. The requirements for this data set included preserving elemental covariance and data characteristics with no loss or distortion, and to create a dataset that would be large enough for research, but not ungainly and requiring a minimum of menial data entry tasks. Our approach to creating this dataset was to leverage existing non-sensitive, non-proprietary datasets that possess similar characteristics to UOC data. The geochemical profile of the igneous rock basalt is quite similar to UOC in many ways, and large, published geochemical datasets are available on-line. Since UOC is approximately 75% U, with varying amounts of minor and trace elements, and basalt is approximately 75% SiO2+Al2O3+CaO+MgO, it was possible to synthetically alter the basalt data to appear superficially similar to UOC. The changes to the basalt data were minor and preserved the essential data characteristics and elemental correlations. The dataset was deliberately sparse, allowing teams evaluate many statistical and evaluative techniques on a realistic looking nuclear forensics dataset. Log 356. DIFFERENTIAL UTILIZATION OF CARBON ISOTOPES BY PSEUDOMONAS PUTIDA. Lujaniene, G.(1); Li, H.-C. (2); Ma.eika, J.(3); Pa.kauskas, R.(3); Remeikait.-Nikien., N.(1); Garnaga-Budr., G.(4); Levinskait., L.(3); Jok.as K.(3); Bugaili.kyt., D.(1); Šemčuk, S.(1); Ka.ergius, A.(5); Stankevi.ius, A.(4); Povinec, P.P.(6) (1) SRI Center for Physical Sciences and Technology, Vilnius, Lithuania. (2) NTUAMS Laboratory at National Taiwan University, Taipei, Taiwan. (3) SRI Nature Research Centre, Vilnius, Lithuania. (4) EPA, Department of Marine Research, Klaipeda, Lithuania. (5) Lithuanian Research Centre for Agriculture and Forestry, Vilnius, Lithuania. (6) Comenius University, Faculty of Mathematics, Physics and Informatics, Bratislava, Slovakia. Pseudomonas putida bacterium was isolated from the Baltic Sea bottom sediments and used in laboratory experiments on differential carbon utilization for better understanding impacts of different sources on 14CTOC variations. The biomass was obtained by growing Pseudomonas putida on Mineral base media under aerobic conditions and identified using standard procedure. To study carbon uptake by Pseudomonas putida in different chemical forms, the biomass was obtained by growing bacteria on media with different source of carbon: Nutrient Broth contained the Beef and Yeas extracts as well as Mineral base contained glucose or/and diesel fuel. To study glucose utilization, its concentrations in the solutions were traced with 14C6H12O6 while Na214CO3 was applied to estimate uptake of inorganic carbon derived from equilibrium with ambient atmosphere. The 14C standard solution in chemical form of Na214CO3 as an inorganic 14C carbon source and D-Glucose as an organic carbon source were used in these experiments. The 14C in biomass was measured using Hidex 300SL (Hidex, Finland) and Tri-Carb 3170TR/SL (PerkinElmer Life and Analytical Sciences, USA) liquid scintillation spectrometers. Preferential glucose utilization (up to 80%) as carbon source, and rather low (from 2% to 10%) inorganic carbon assimilation were found in media with diesel fuel. Pseudomonas putida, a specific biomarker analyzed in biomass cultivated on the media with different carbon sources has been used to characterize microbial communities responsible for organic substances degradation in bottom sediments.


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Log 357. RADIOCHEMISTRY EDUCATION AT THE UNIVERSITY OF NEVADA, LAS VEGAS: COMBINING FUNDAMENTAL AND APPLIED STUDIES. Czerwinski, K.R., (1); Poineau, F. (1). (1) Radiochemistry Program, Department of Chemistry, University of Nevada, Las Vegas Technetium and the actinides are radioelements of importance to the nuclear fuel cycle. Compounds composed of these elements are used in nuclear fuel, separations, safeguard applications, and isotope utilization. These radioelements also represent an underexplored section of the periodic table. Studies on compounds with technetium and the actinides provide opportunities to expand basic chemical knowledge, particularly when coupled with computational studies. Performing experiments with these elements requires specialized facilities and radiochemical expertise. The training of students and scientific rewards for examining this relatively unexplored area of the periodic table are worth the intrinsic difficulties associated with experiments using these elements. The radiochemistry program at the University of Nevada, Las Vegas is described, with emphasis given to the facilities, education mission, and collaborations. The linkage of the UNLV radiochemistry program with DOE and international research efforts is presented. Examples are provided on separations, fuel synthesis, and waste form studies. The incorporation of internet lectures with a laboratory intensive program for undergraduates is also described. The undergraduate program has been demonstrated as an effective pipeline for student recruitment to graduate programs. Log 358. COUPLING RADIOELEMENT SPECIATION WITH FORENSICS SIGNATURES. Campbell, K. (1); Wozniak, N. (1); Koury, D. (1); Czerwinski, K.R. (1). Radiochemistry Program, Department of Chemistry, University of Nevada Las Vegas. There is a clear desire to improve signature identification for nuclear forensics. A useful approach involves the incorporation of radioelement and radionuclide speciation. Identifying the radionuclide chemical form can be used in different aspects of nuclear forensics. Exploiting the speciation of targeted radionuclides in samples can aid in separations, decreasing time needed for isotope evaluation. For analysis, molecular forensics science has been shown to provide useful information on material of interest. Both these improvement leverage radionuclide speciation in improving forensic analysis. Molecular forensics science provides signatures based on chemical speciation, structure, morphology, and trace composition. As actinide materials are processed for nuclear applications, potential signatures exist that can provide data on origin, separation dates, and chemical treatment. An example is provided for uranium oxides. The use of spectroscopy and microscopy analysis is used to demonstrate the utility of molecular forensics science in identifying signatures. Microscopy analysis revealed origin of uranium oxides. Morphological features provided insight into process conditions for uranium oxide species. Synchrotron spectroscopy gave information on speciation and element correlation. The results are used to provide a means in assessing material to provide forensics signatures.


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Log 359. ISOTOPE HARVESTING OF Zr-88 AND THE MEASUREMENT OF ITS NEUTRON-CAPTURE CROSS SECTION. Shusterman, J.A. (1); Scielzo, N.D. (1); Abel, E.P. (2); Dronchi, N.D. (2); Hart, J.A. (2); Lapi, S.E. (3), Loveless, C.S. (3); McGuinness, S. (4); Norman, E.B. (5); Peaslee, G.F. (4); Robertson, J.D. (6); Severin, G.W. (2); Shaughnessy, D.A. (1), Stoyer, M.A. (1); Sutherlin, L. (6); Thomas, K.J. (1); Tonchev, A.P. (1). (1) Lawrence Livermore National Laboratory. (2) Michigan State University. (3) University of Alabama, Birmingham. (4) University of Notre Dame. (5) University of California, Berkeley. (6) University of Missouri. The nuclear-reaction networks involving the radioactive Zr isotopes, of significant importance to the stockpile-stewardship program and to nuclear astrophysics, have notable gaps in cross-section data. One of the isotopes of interest, Zr-88, is lacking any experimental measurements of the neutron-capture cross section. To provide the first experimental determination of the neutron-capture cross section, Zr-88 was produced, chemically purified and made into targets, and then irradiated in a reactor. After irradiation the samples were counted using gamma spectroscopy, monitoring the ingrowth and decay of various species. The Zr-88 target material was produced through two different methods: traditional charged-particle reactions and isotope harvesting. The charged-particle reaction was 89Y(p,2n)88Zr using proton beams from both the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory and a cyclotron at the University of Alabama, Birmingham. Isotope harvesting was done at the National Superconducting Cyclotron Laboratory at Michigan State University in preparation for when the Facility for Rare Isotope Beams (FRIB) comes online. The Zr-88 was harvested by collecting Zr-88 beam in a water target using the aqueous isotope harvesting end station. Following chemical purification of the Zr-88, irradiations were performed at the University of Missouri Research Reactor. We determined that the experimental neutron-capture cross section deviates substantially from the predicted value, further demonstrating the importance of experimentally determining these quantities. Once FRIB comes online, greater quantities of hard-to-produce nuclides are expected to become available if harvested. These may allow for the measurement of other cross-sections that will aid in interpreting new surrogate debris and historic stockpile-stewardship data. Log 360. PREPARATION, CERTIFICATION, DISTRIBUTION, AND CONTRIBUTION OF CERTIFIED REFERENCE MATERIALS OF FISH BONE AND MEAT FOR DETERMINATION OF STRONTIUM-90 AND RADIOCESIUM AFTER FDNPP. Minai, Y. (1), Miura, T. (2), Yonezawa, C. (3), Kakita, K. (4), Kojima, I. (4), Okada, Y. (5), Uematsu, Y. (6), Okada, A. (7), Hirai, S. (5). (1) Musashi University and Nedzu Chemical Laboratory. (2) Advanced Industrial Science and Technology. (3) Japan Institute of International Affairs. (4) Japan Society for Analytical Chemistry. (5) Tokyo City University. (6) Japan Accreditation Board. (7) Toshiba Environmental Solution Co. After FDNPP, our group developed several certified reference materials of foodstuffs and agricultural products for determination of radiocesium, supported by Japan Science and Technology Agency (JST). The final reference materials in this program was fish meat and bone, which accumulated Sr-90, developed just at MARC-X three years ago. At the conference we mentioned on the presence of the fish CRMs as an on-going development. This paper reports the details on preparation and certification procedures and some technical efforts and social contribution in these three years. In spring to summer in 2014 many individuals of okamejei and kenojei fish were taken from the Fukushima coast. After screening by gamma-assay, selected individuals were separated into two portions: bone and meat parts. It was found that Sr-90 was accumulated in bone part whereas Cs-134 and Cs-137 distributed in both bone and meat parts. The fish bone CRM targeted to be used for Sr-90 determination because the fish meat contained Cs-134 and Cs-137 from the same origin. We chose ash form for the bone CRM due to its stability in preservation; that was a right way based on observation until present. After the certification procedure including round-robin test by the domestic institutes, both CRMs started to be distributed. Tentative summary of international collaboration for testing the CRMs showed no discriminative values reported from the domestic laboratory.


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Log 361. MASSIC ACTIVITY OF A PROTACTINIUM-231 SOLUTION DETERMINED BY TWO METHODS. Fitzgerald, R. (1); Collé, R. (1); LaRosa J. (1); Nour, S. (1); Laureano-Perez, L. (1); Pibida, L. (1). (1) National Institute of Standards and Technology. As part of the recent effort to make a highly-characterized Pa-231 calibrant for Isotope Dilution Mass Spectrometry (IDMS), we report on activity measurements of Pa-231 in a solution that had been purified by Lawrence Livermore National Laboratory (LLNL) and sent to multiple laboratories for characterization of molality and massic activity. The massic activity was determined by two independent methods, gross Liquid Scintillation (LS) counting and alpha spectrometry. The LS counting was sensitive to the Pa-231 and its daughters. The initial activities of the Pa-231 daughters at the time of the separation at LLNL were derived by solving the Bateman equations for daughter activities measured by gamma-ray and beta-particle measurements at NIST. These initial daughter activities and their uncertainties were used as inputs into an LS efficiency model that was used to extract the Pa-231 activity from the gross LS counting rates. The second activity-determination method was alpha spectrometry using Pa-233 as a radiochemical tracer, detected by gamma-ray measurement. The Pa-231 activity measurement uncertainty is comparable to the uncertainty in the half-life of 0.8 %, thus can serve as the basis of a new half-life determination or as a check on the IDMS measurement results. Log 362. DETAILED FIB-SEM CHARACTERIZATION OF URANINITE: IMPLICATIONS FOR TRACE ELEMENT ABUNDANCES DETERMINED BY LA-ICP-MS ANALYSIS. Lewis, S. (1); Simonetti, A. (1); Chung, B.W. (2); Teslich, N.E. (2); Corcoran, L. (1); Spano, T. (1); Burns, P.C. (1). (1) Univeristy of Notre Dame, CEEES Department. (2) Lawrence Livermore National Laboratory. Nuclear forensic analyses involve the use of both predictive and comparative signatures to ascertain origin, age, and the type of processing. In order to better understand these signatures, it is critical to characterize the chemical and isotopic signatures of the primary natural U-bearing ore, namely uraninite (UO2+x). Hence, in this study, in-situ analyses were conducted on uraninite from Ruggles Mine, NH, and Marshall Pass, CO. Abundances of major elements were determined by electron microprobe (EMP) analyses, which were used as internal standards in laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) analyses to determine trace element concentrations. Selection of various elements (i.e. Pb, Ca, Zr, etc.) as the internal standard yielded highly variable trace element concentrations (up to several orders of magnitude). Thus, focused ion beam (FIB) coupled with scanning electron microscopy (SEM) investigations were performed to attain a 3-dimensional distribution of elements within the uraninite. Multiple EDS analyses of FIB cross sections exhibited significant variations of elemental wt% abundances for a 15 µm2 area. Within pristine grains, Pb varied up to 6 wt% while altered grains exhibited elemental variations up to 17 wt% (e.g., W). These large differences in elemental wt% concentrations within a 15 µm2 cross section reinforces the need for choosing an appropriate internal standard. Based on the results obtained thus far, pristine uraninite’s optimal internal standard is Pb because it appears to be structurally bound/incorporated within the uraninite whereas the remaining elements (e.g., Ca and W) seem interstitial. Log 363. THE DETECTION OF UNDERGROUND NUCLEAR EXPLOSIONS BY NATURAL SIGNATURES. Burnett, J.L. (1); Ely, J.H. (1). (1) Pacific Northwest National Laboratory The detection of low-yield underground nuclear explosions (UNEs) is challenging due to containment measures undertaken to prevent escape of radioactive signatures. These signatures include fission and activation products generated from the explosion. Measures may also be undertaken to restrict generation of seismic and infrasound signatures. A new approach is proposed to detect such tests using natural and activated signatures. Natural signatures include increased release of radon gas isotopes (Rn-222 and Rn-220) from the disturbance and pressurization of the sub-surface flow regime caused by a UNE. Whilst physical barriers can be constructed to ensure containment, measures are not typically implemented to restrict radon escaping from beyond the containment cage around the cavity. It is envisaged such soils, rock and pore waters are placed under significant stress and agitation by the explosion, and would be subject to increased radon release. Activated signatures include the activation of natural radionuclides present in the soil and rock, to produce signatures indicative of a UNE. This includes radon isotopes not commonly detected in the environment that could be released to the surface in the aforementioned manner.


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Log 364. RADIOLOGICAL SEALED SOURCE LIBRARY: A NUCLEAR FORENSICS TOOL AIDING IN MATERIAL IDENTIFICATION, RESEARCH INITIATIVES AND NUCLEAR SECURITY CAPACITY BUILDING. Canaday, J.L. (1); Chamberlain, D.B. (1); McLain, D.R. (1); Youker, A.J. (1). (1) Argonne National Laboratory If radiological sealed sources are obtained by a terrorist for malevolent use, the sealed sources have the potential to be incorporated into an RDD (commonly referred to as a 'dirty bomb') or an RED. The identification of the radiological sealed source and material may prove necessary to determine the loss of control point and the last legal owner of the material. The Radiological Sealed Source Library is a nuclear forensics tool, which contains forensic signatures of radiological materials, sealed radioactive sources, and the devices that house them. The traditional purpose of the library is to aid U.S. government agencies, including law enforcement and first responders, in identifying the radioactive source or device, including the manufacturer and distributor. The library a searchable collection of pictures, construction diagrams, dimensions, and chemical compositions of sources and devices sold anywhere in the world. The information encompasses both currently distributed source and device models and historical, discontinued ones. The latter are necessary because the half-life of many nuclides in sealed sources and radioactive devices is beyond that of most current commercial products. The libraries rich data set has enabled the expansion beyond traditional purpose to include identifying and broadening laboratory research initiatives, and radiological security capacity building through workshops and scenario based exercises. This presentation will highlight the Radiological Sealed Source Library and its continued contribution to laboratory research initiatives and radiological security capacity building Log 365. SOLUBILIZATION OF URANIUM DIOXIDE WITH FLUORINATING IONIC LIQUIDS. Zarzana, C.A. (1); Groenewold, G.S. (1); Benson, M.T. (1); Martens, J. (2); Oomens, J. (2); Hagiwara, R. (3) (1) Idaho National Laboratory. (2) Radboud University, The Netherlands. (3) Kyoto University, Japan. Nuclear energy is a key component of the future global low-carbon energy portfolio. One of the challenges for large-scale nuclear deployment is the ultimate disposition of used nuclear fuel. Ionic liquids have unique, tunable properties that may enable the development of new partitioning processes with lower solvent consumption, lower waste generation, and greater safety than traditional separation processes. We have investigated the ability of the fluorinating ionic liquid 1-ethyl-3-methylimidazolium fluorohydrogenate [(EMIm)F(HF)2.3], to act as a solvent for used fuel separations. Uranium dioxide (UO2) dissolved in neat 1-ethy-3-methylimidazolium fluorohydrogenate ionic liquid [EMIm+][F(HF)2.3-] to a generate blue-green solution, that slowly (over the several weeks) changes to yellow. Analysis of the UO2-containing solution by electrospray mass spectrometry revealed the primary anion component to be UF6- (uranium in the +5 oxidation state), indicating that [EMImF(HF)2.3] oxidizes and fluorinates uranium upon dissolution. The positive ion spectrum mainly consisted of cluster ions formed from the components of the ionic liquid; however, a low abundance ion at m/z 574 was formed that corresponded to [EMIm+]2[UF6-]. Analysis of the aged, yellow ionic liquid solutions using electrospray mass spectrometry and infrared spectroscopy suggest that the UF6- is slowly oxidized to uranyl fluoride. Lanthanides also appear to dissolve, but do not produce detectible ions, offering the possibility of separation of uranium from the lanthanides without the use of additional ligands. Thus, fluorinating ionic liquids could offer new modes for separating used nuclear fuel, reducing the complexity of partitioning processes, and consequently the overall cost.


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Log 366. RADIOCHEMICAL SEPARATIONS AND EXPERIMENTAL MEASUREMENTS OF SHORT-LIVED FISSION PRODUCTS FROM 14 MEV IRRADIATION OF DEPLETED URANIUM. Arrigo, L.M. (1); Greenwood, L.R. (1); Pierson, B.D. (1); Metz, L.A. (1); Friese, J.I. (1). (1) Pacific Northwest National Laboratory. This work focused on the experimental analysis of depleted uranium irradiated with 14 MeV neutrons to obtain fission yields for 20 fission products with half-lives ranging from 16.8 hours to 30.1 years. Depleted uranium was irradiated at the Pacific Northwest National Laboratory using a deuterium-tritium neutron generator for 24 hours. Following dissolution the sample was split such that a portion was gamma counted using a high purity germanium (HPGe) detector for quantification of multiple high-yield fission products. Additionally, a portion went through several radiochemical separations followed by gamma and liquid scintillation counting for quantification of low-fission yield and/or predominately beta emitting isotopes. Due to half-life constraints for some of the radionuclides these separations must be performed quickly; the chemistry and sample preparation for all the radionuclides was completed in less than 72 hours post sample dissolution with many radionuclides prepared in less than 48 hours. The required separations will be described along with a comparison to the reported Evaluated Nuclear Data File (ENDF) fission yield and other experimental measurements. Log 367. DEVELOPMENT OF A NEW URANINITE REFERENCE MATERIAL FOR NUCLEAR FORENSIC ANALYSIS AT HIGH SPATIAL RESOLUTION. Dorais, C. (1); Spano, T. (1); Balboni, E. (2); Simonetti, A. (1); Hixon, A.E. (1); Burns, P.C. (1). (1) University of Notre Dame. (2) Lawrence Livermore National Laboratory. There is currently a lack of well-characterized, matrix-matched, uranium-bearing reference materials (RMs) for nuclear forensic analysis at high spatial resolution. To address this deficit, we have characterized a uraninite (UO2) that can be used as a RM to validate chemical and isotopic signatures in nuclear materials. In this study, uraninite from Utah (USA) was identified using powder X-ray diffraction (pXRD) and then characterized for its major, minor, and trace element abundances using a variety of micro-analytical techniques. The chemical signatures of the uraninite were investigated at the macro (cm)-scale with micro-X-ray fluorescence (uXRF) mapping, and at high-spatial resolution (10s of micron-scale) using electron microprobe (EMP) and laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses. Based on EMP analysis, the uraninite is fairly homogeneous and contains, on average, 90.37+-0.58 % UO2 and 2.67+-0.13 % CaO. Due to its homogenous distribution, CaO abundances were used as the internal standard when conducting LA-ICP-MS analyses in order to calculate trace element abundances and monitor for instrumental drift. Chondrite-normalized rare earth element (REE) abundances show depletion in the light REEs, particularly for lanthanum, with the remaining REEs defining a flat pattern at levels just slightly above 1000 times chondrite. Overall, the major and trace element compositions are fairly homogeneous at both the centimeter and micron scale, allowing this material to be used as a RM for high spatial resolution analysis.


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Log 368. RADIOCHEMICAL SEPARATION OF SM FROM P-IRRADIATED TA TARGETS, TOWARDS A HIGH-PRECISION HALF-LIFE MEASUREMENT OF 146Sm. Talip, Z. (1); Dressler R. (1); Schumann D. (1). (1) Laboratory for Radiochemistry, Paul Scherrer Institute, Switzerland. 146Sm is an important nuclide in nuclear astrophysics with respect to the understanding of the history and development of our solar system. The alpha decay of 146Sm to 142Nd is considered as a suitable Solar-System chronometer for the selective information on very early events (>4.2 Gya). In order to apply it, it is necessary to know the existence time of 146Sm in the early solar system, and thus, an accurate knowledge of the 146Sm half-life value is mandatory. The half-life of 146Sm has been measured five times over the last 64 years. However, there is a 30 % discrepancy between the recent measurement (68±7 My) and the previously accepted value (103.1 ± 4.5 My). In order to answer this open question, there is definitely an urgent need to re-measure the half-life of 146Sm, but, so far, is hampered by the lack of sufficient sample material. Highly activated components from the surroundings of the PSI high-power accelerator facilities are a unique source for this extremely rare sample material. We report here on the exploitation of highly activated metallic Ta pieces from the second SINQ Target Irradiation Program (STIP II) to produce a 146Sm sample containing at least 1017 atoms. In this paper, the applied radiochemical separation procedures are described. The material will be used to perform a high precision half- life measurement of 146Sm with an uncertainty lower than 5%, using high-resolution alpha spectrometry and multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Log 369. NEW DETERMINATION OF THE Th-229 HALF-LIFE. Essex, R.M. (1); Mann, J.L. (1); Collé, R. (1); Laureano-Perez, L. (1); Bennett, M.E. (2); Dion, H. (3); Fitzgerald, R. (1); Gaffney, A.M. (4); Gourgiotis, A. (5); Hubert, A. (6), Kinman, W.S. (3); Lamont, S.P. (3); Steiner, R. (3); Williams, R.W. (4). (1) NIST. (2) Argonne National Laboratory. (3) Los Alamos National Laboratory. (4) Lawrence Livermore National Laboratory. (5) IRSN. (6) CEA. A new determination of the Th-229 half-life, based on measurements of the Th-229 massic activity and the Th-229 molality of a high-purity solution, is reported. A Th-229 master solution was prepared and calibrated for massic activity (Bq/g) at the National Institute of Standards and Technology (NIST) as part of the certification effort for Standard Reference Material 4328C. A dilution of this master solution was later used for a new reference material that was characterized for the molality (mol/g) of Th-229 and intended for use as a thorium isotope dilution mass spectrometry spike. The Th-229 massic activity of the molality standard was measured by direct comparison with SRM 4328C using 4π-. liquid scintillation counting, NaI(Tl) photon counting, and standard addition liquid scintillation counting. The Th-229 massic activity was confirmed by isotope dilution alpha spectrometry measurements and is consistent with the expected value based on the dilution of the master solution. The Th-229 half-life derived from this work is 0.8% to 1.7 % shorter than published half-life values, but is largely consistent with the earlier determinations (i.e. within or overlapping uncertainties at the 95% level of confidence). Log 370. X RAY DETECTOR SUPER RESOLUTION WITH GHOST IMAGING METHOD. Zhongwei, Z. (1); Yuewen, S. (1); Xincheng, X. (1); Peng, C. (1). (1) Institute Of Nuclear And New Energy Technology, Tsinghua University Ghost Imaging(GI) is a technique that uses a single pixel detector and several known random patterns to obtain a 1D signal sequence to reconstruct a 2D image. A Digital Micromirror Device(DMD) is used to generate different random patterns in visible light imaging. In this paper, we propose a novel technique to increase resolution of X Ray detector using GI method. A sub pixel random lead pattern instead of DMD is inserted in front of a 2D low resolution detector to obtain one sampling image of the object, therefore, a series of different patterns produce a low-resolution image sequence. A high-resolution image can be reconstructed using this image sequence based on Compressive Sensing(CS) theory. A numerical and a Monte Carlo simulation experiments were made to verify the performance of our technique and successfully reconstructed a 256*256 pixel image from a 64*64 2D detector.


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Log 371. INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS OF REDDISH PIGMENTS FOR JAPANESE PAINTINGS. Minai, Y. (1, 2); Wall, D. (2); Wall, N. A.(2); Tomizawa T. (3); Okada, Y. (4); Yamada, Y.(5). (1) Musashi University and Nedzu Chemical Laboratory. (2) Washington State University. (3) Keio University. (4) Tokyo City University, (5) Tokyo University of Science. Instrumental neutron activation analysis is useful for trace element analysis of art works, thanks to its high sensitivity and non-destructive nature. In this work were analyzed 26 pigment samples commercially available in Japan to establish analytical procedures for classification of pigments and determination of trace elements. One hundred milligrams sample of each pigment were sealed in a polyethylene vials and were activated, using the 1 MW TRIGA research reactor at Washington State University. The samples were initially screened by irradiating for 1 min at 100 kW reactor power. Based on the gamma-ray spectra, the pigments composed of mercury or arsenic sulfides were distinguished from the pigments bearing natural iron oxides or artificially colored glass powder. Analytical results of Moessbauer and x-ray analyses were used to classify the samples that had been screened by NAA. The samples were irradiated for up to 1 hour at a reactor power of 1 MW. The pigments were grouped according to their major components and minor components: mercury sulfides containing As and Sb, arsenic sulfides with Sb, ferric oxides containing Na, Al, Cr, Mn, Co, As, Sb, La, and artificially colored glass containing Na, Al, and other trace elements. Based on the irradiation and sample handling conditions from the present study, we can estimate the amount of sample and conditions that are required to reach the analytical goals as well as the time for decay of the induced radioactivity which is a major concern for investigation of precious paintings. Log 372. AN EVALUATION OF SEPARATION PROCEDURES FOR AGE DATING Se-75 GAMMA RADIOGRAPHY SOURCES. McLain, D.R. (1); Canaday, J.L. (1); Tsai, Y. (1); Graczyk, D.G. (1); Finck, M.R. (2); Youker, A.J. (1); Chamberlain, D.B. (1). (1) Argonne National Laboratory. (2) Idaho National Laboratory. Selenium-75 is an up-and-coming radioisotope used in industrial radiography. It is particularly attractive because it has a longer half-life and softer x-ray emission than Ir-192, resulting in less dose to end users because of fewer source change-outs in the same period. One drawback to Se-75 is that it decays into stable As-75, which is highly toxic. This characteristic may make Se-75 sources a target for use in a radiological dispersal device (RDD) despite its relatively short half-life (119.78 d). Because of the novelty of the source, however, there are no currently established methods for analysis. Other isotopes of selenium and arsenic are important to current industries. As a long-lived fission nuclide that is highly mobile in the environment, Se-79 is important to decommissioning and waste management activities. In addition, As-72 has found use in positron emission tomography (PET) diagnostic medical imaging, which requires stringent purification of arsenic. As a result of these uses, several different separation schemes have been developed for the individual elements. These methods cover a wide range of techniques, from arsenic distillation to ion exchange and extraction chromatography. This presentation will cover work that looks to compare the available methods and determine if any are applicable to age dating Se-75 sources.


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Log 373. KINETICS OF RADICAL-INDUCED DEGRADATION OF DIGLYCOLAMIDES. Twight, L. (1); Mezyk, S.P. (1); Mincher, B.J. (2). (1) California State University at Long Beach. (2) Idaho National Laboratory. An understanding of the influence of radiation on separation ligands is critical to the development and implementation of robust fuel cycle processes. While extensive work has recently been reported on the radiations-induced degradation of the higher molecular weight lipophilic diglcolamides (DGAs) in organic media, little kinetic or radiation-induced degradation of the lower molecular weight DGA species in aqueous solution exists. Compounds such as tetraethyldiglycolamide (TEDGA) and tetramethyldiglycolamide (TMDGA) have been used as lanthanide stripping agents from the ALSEP solvent to regenerate that solvent. TEDGA has also been used to separate americium from curium. However, the overall efficiency of these agents may be changed by radiation-induced degradation. In this study we report on the kinetics of hydroxyl (•OH), nitrate (•NO3) and hydrogen atom (H•) radical reactions with two hydrophilic DGAs in water. Electron pulse radiolysis experiments were performed using the LINAC system at the University of Notre Dame Radiation Laboratory. The reaction kinetics of the •OH radical with TMDGA and TEDGA were directly measured through observation of the initially formed intermediate, those for •NO3 by the direct decay of this radical, and H• by competition kinetics. Similar reactivity for the •OH and H• atom for both species was observed, however, the •NO3 radical reaction with TEDGA was far slower than for TMDGA. Log 374. APPLICATION OF GRAPHENE OXIDE BASED NANO-COMPOSITES FOR THE REMOVAL OF RADIONUCLIDES AND METALS FROM CONTAMINATED SOLUTIONS. Lujanienė, G. (1); Kulakauskaitė, I. (1);, Šemčuk, S. (1); Lečinskytė, A. (1); Tautkus, S. (2); Valiulis, D. (1); Juškėnas, R. (1); Laurinavičius, D. (1). (1) SRI Center for Physical Sciences and Technology, Lithuania. (2) VU Faculty of Chemistry, Lithuania. Graphene oxide (GO) based nano-composites belong to thegroup of the mostpromising sorbents capable of efficiently removing radionuclides and toxic elements from various environmental matrixes and contaminated solutions. Graphene oxide based – magnetic (MGO), Prussian blue (PBGO, MPB, MPBGO ) and chitosan (GOCS) composites of the nano-particle size of < 10 nm were synthesized, characterized and used in sorption experiments. The adsorption of Cs(I), Co(II), Ni(II), Cu(II), Pb(II), Am(III) and Pu(IV) to nano-composites was studied in a wide range of initial concentrations and analyzed by Langmuir and Freundlich models. In addition, the effects of pH and coexisting ions on the adsorption of Cs to Prussian blue based composites were investigated. The maximum adsorption capacities of studied elements varied from 30 to 800 mg g-1. The obtained Langmuir and Freundlich constants indicated the dominating physisorption mechanism and favourable adsorption conditions. The maximum values of 99% and 98% for Pu and Am sorption to CSGO wereobserved at pH of 4 and 5, respectively. The obtained results have indicated the highest qe values of GO for Pb, while the qe values for Cu, Ni and Co decreased in the following order: Cu> Ni >Co. The maximum adsorption capacity was not reached for Pb ions. Qmax values varied depending on the studied element. Qmax values for Cu2+ increased in the order of M < MPB < MPBGO with the highest value of 1.28 mmol/g for MPBGO. The studied nano-composites were applied for the sorption of radionuclides and metals from the seawater.


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Log 375. LOW LEVEL GENERATOR OF Ge-68/Ga-68 FOR MULTIPURPOSE USE IN EDUCATION. Nozaki, T. (1), Nagatsu, K. (2), Minai, Y. (3), Sasaki, T. (1). (1) Kitasato University. (2) National Institute of Radiological Sciences. (3) Musashi University and Nedzu Chemical Laboratory. Growing importance of radiochemistry and its application in modern society, wide range of educational programs are needed for general public and students, including non-science majors. In particular, experimental programs for those having less opportunity to have knowledge on radiation and radioactivity were developed seldom. Radioisotope generator system like Ge-68/Ga-68 pair, which is popular in nuclear medicine, would be highly suitable for such purpose. Besides, intensive course can be developed for students having basic knowledge on radiochemistry. At first was developed an experimental course for undergraduate students majoring natural science. The laboratory course began from manufacturing the generator for their own use. The amount of Ge-68/Ga-68 generator was planned as lower than 100 kBq. Then students can pick up about 20 items of experiments out of many candidates. Those items were well tested; the students can conduct the laboratory work following the manual for each item. The developed contents using the generator can be grouped into three categories: (1) manufacture and measurement of properties of the generator; (2) use of the carrier-free Ga-68 for various tracer studies; (3) use as a positron source. Based on the success of the laboratory class for students of science major, we can start to develop new programs for non-science majors, general public, and high school students. This would be a long-term program associated with careful preparation and reviewing. Recently, we started to prepare introductory manuals for this program. The test operation of the program for undergraduate students of non-science major is now on schedule. Log 376. STREAMLINED MONTE CARLO SIMULATION OF ENVIRONMENTAL GAMMA-RAY BACKGROUNDS FOR RADIATION DETECTOR SENSITIVITY COMPARISONS. Keillor, M.E. (1); Campbell, L.W. (1); Cowles, C.C. (1); Dion, M.P. (1); Ely, J. (1); Neumann, C.R. (1). (1) Pacific Northwest National Laboratory. In a recent effort to compare the detection sensitivity of a variety of gamma radiation detectors applied in in-situ and lightly shielded field laboratory scenarios, the authors found that a lack of 'apples-to-apples' background measurements with the different detectors presented significant challenges in the detection sensitivity calculations. To overcome this hurdle, Monte Carlo modeling of the terrestrial environmental gamma radiation and experimental measurements were undertaken. Inspired by the work of Vojtyla to reduce the computing burden of modeling bremsstrahlung emitted from the surface of lead, a related approach was taken to define a gamma-ray surface source that would adequately represent the emission of natural gamma-rays from the earth's surface. This work will present the definition of a surface source that is based on the potassium, uranium, and thorium content of a local soil, and provide a comparison to experimental in-situ gamma measurements.


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Log 377. DETERMINING AQUEOUS COMPLEXATION AND EXTRACTION KINETICS FOR LANTHANIDE IONS THROUGH LUMINESCENCE. Larsson, K. (1); Mezyk, S.P. (1). (1) California State University at Long Beach. Understanding the chemistry of the different extractant and aqueous complexant species used in the extraction and separation of lanthanides and actinides from used nuclear fuel requires that the complexation kinetics of the different ligands with metals be quantitatively evaluated. In this work, complexation kinetics of the europium ion by the aminopolycarboxylic acid DTPA (diethylenetriaminepentaacetic acid) were directly measured using the luminescence change of europium in aqueous solution. Competitive complexation was also used to obtain data for other lanthanide ions, including the exchange rates for these different metal ions. Applying the same luminescence-based technique in the organic phase allows for the determination of bulk phase rate constants for the organic extractant HDEHP with europium and terbium. The initial experiments on the bulk organic phase rates indicate that the formation of the final complexes is slow, with approximately 600 seconds required to reach a stable signal. This means that the slow kinetics of HDEHP extraction of lanthanides can be related to the bulk organic rates. The measured luminescence response is however very temperature dependent. This approach aims to understand the kinetics occurring within the solvent extraction based metal separation method for lanthanide/ actinide separations by applying the established rate constants for the individual phases together with extraction experiments to better determine also the interfacial kinetic properties, thereby allowing the complete modelling of extraction systems. Log 378. PROGRESS IN STUDY ON THE COMPLEXATION OF An(III)/Ln(III) WITH PURIFIED CYANEX301 IN LAST TWO DECADES. Yang, S. (1); Zhang, Y. (1); Li, D. (1); Yuan, X. (1); Wei, Z. (2); Tian, G. (1, 2). (1) China Institute of Atomic Energy, China. (2) Department of Nuclear Engineering, Harbin Engineering University, China. Since the excellent selectivity of purified Cyanex301 (bis(2,4,4-trimethylpenty dithiophosphinic acid) was reported two decades ago, a variety of techniques has been deployed to investigate the complexation of An(III)/Ln(III) with Cyanex301. By using EXAFS, IR, TRLFS, it was found that water molecules play significant role in the extraction of An(III)/Ln(III) with Cyanex301. For the light lanthanides, there are some water molecules directly bonding to the metal ions, while there is no water molecule founded in the extracted complexes of An(III). After about 10 years, the investigation was extended to cross the whole lanthanide series. The results from EXAFS, UV-Vis absorption spectroscopy, and fluorescence spectroscopy indicate that the extracted complexes change from light to heavy lanthanides at 25 degree Celsius . The participation of the Cyanex301 molecules to the complexation gradually diminishes from light to heavy lanthanides, and ends at Gd(III). For heavy lanthanides from Gd(III) to Lu(III), the metal ions are fully hydrated and there is no ligand directly bonding to Ln(III) in the extracted complexes at 25 degree Celsius. Recently, it was found that there are two extracted complex species for each lanthanide element ion. In one species, about three oxygen atoms from three water molecules and six sulfur atoms from three Cyanex301 molecules directly bond to Ln(III) in the first coordination shell. In contrast, in the other species, the Ln(III) is fully hydrated and there is no ligand molecule in the first coordination shell. The most interesting point is that the proportion of the two species is very sensitive to the temperature. The fully hydrated species favors low temperature, while the species directly bonded by the Cyanex301 anions is stabilized at higher temperature. The heavier, higher temperature is needed to stabilized the species directly bonded by the Cyanex301 anions.


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Log 380. SODIUM BISMUTHATE SOLUBILITY IN NITRIC ACID SOLUTIONS FOR AMERICIUM SEPARATIONS. Prem, P. (1); Mezyk, S.P. (1); Horne, G.P. (2); Mincher, B.J. (2); (1) California State University at Long Beach. (2) Idaho National Laboratory. The expansion of nuclear power as an alternative energy source is limited by the management of its radioactive waste. Rather than storing all spent nuclear fuel in long-term geological repositories, where it remains a radioactive hazard for tens of thousands of years, selected radioactive elements, particularly Americium (Am), may be separated and recycled as a fuel source in current and advanced reactors. Unfortunately, the process is made difficult by the chemical similarity of Am(III) to the other trivalent actinides and lanthanides. One separations approach is to oxidize Am(III) by sodium bismuthate in nitric acid solutions to generate hexavalent Am(VI), which then allows it to be readily separated through straightforward solvent extraction techniques. This process requires the reduction of dissolved Bi(V) to Bi(III), but it is limited by the solubility of sodium bismuthate in nitric acid solutions. This limited solubility limits the efficiency of the overall Am oxidation process. Moreover, there are currently no quantitative solubility limits for sodium bismuthate in nitric acid solutions, particularly at non-ambient temperatures. Here we report on our initial NaBiO3 solubility measurements in various nitric acid concentrations, over a range of temperature. Establishing these solubility parameters, especially in the presence of other anticipated extraction process chemicals, could allow Am(V) production optimization which would provide a more effective, optimal, technique for its separation from lanthanides and other actinides at large-scale. Log 382. DEPENDENCE OF UO2 ON SURFACE MORPHOLOGY ON SYNTHESIS ROUTE. Abbott, E.C. (1); McDonald, L.W. (1). (1) University of Utah. Surface morphology of uranium oxides is a defining characteristic of the processing history of the material. Many synthetic pathways can be used for the production of UO2 including the peroxide, ammonium diuranate, and ammonium uranyl carbonate routes. Regardless of the precipitation reaction used to initiate the synthetic pathway, most commercial processes go through UO3 or U3O8 during production of UO2. In this study, the impact of UO2 morphology, based on the U-oxide intermediate (i.e. am-UO3, alpha-UO3 or U3O8), was evaluated. The intermediate U-oxides were reduced to UO2 using identical calcinations; specifically, they were reduced under hydrogen at 510 °C. The resulting UO2 and parent materials were analyzed using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and powder X-ray diffractometry (XRD). SEM was used to monitor changes in the morphology; while XRD and XPS were used to verify the purity of the final product. The Morphological Analysis for MAterials (MAMA) software was used to segment the SEM images and quantify the morphological changes. Statistical analysis proved that the UO2 surface structure and morphology varied based on the intermediate U-oxide used during synthesis. Differences in the p-XRD spectra for UO2 made from amorphous UO3 and alpha-UO3 versus U3O8 suggest a different mechanism for the conversion of these intermediate U-oxides to UO2. Hence, quantitative p-XRD analysis was performed to identify the mechanism of am-UO3, alpha-UO3 and U3O8 reduction to UO2 which is causing the difference in the final product morphology.


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Log 383. CORRELATION EFFECTS IN GAMMA SPECTROSCOPY EFFICIENCY CALIBRATIONS AND THEIR IMPACT ON ACTIVITY AND UNCERTAINTY QUANTIFICATION. Kirkpatrick, J.M. (1); Anderson, T. (1); Oginni, B. (1); Persson, H. (1); Phillips, K. 1). (1) Mirion Technologies (Canberra), Inc. The requirements of high-precision gamma ray spectroscopy applications increasingly demand greater accuracy from analysis software, in terms of both the determination of nuclide activities and the quantification of measurement uncertainty. To this end, we report on recent work to implement enhanced analysis algorithms for the Genie 2000 software suite that account for the most important effects of correlations between analysis input data in a statistically rigorous way. These effects primarily arise through the calibration procedure, wherein a mathematical function is fit to a set of measured efficiency data points, inevitably resulting in correlations between calculated efficiency values at different energies. While these effects are often relatively small, and thus have historically been considered of minimal significance, they can have important effects on activity results in applications where high precision is called for, especially for multi-line nuclides. The impact of correlations on uncertainty quantification is often more apparent, and may be significant even when precision requirements are not as stringent. Correlation effects are often particularly noticeable in cases where the measured efficiency data are themselves correlated, as when calibration measurements are performed using sources containing multi-line nuclides. In this paper, we discuss the physical mechanisms by which correlations are introduced and describe the mathematical methods by which they are evaluated and propagated in the new algorithms. Quantitative examples are presented to demonstrate the improvement on analysis output. Log 384. KINETICS OF RADICAL-INDUCED METAL-EXTRACTION SPECIES DEGRADATION IN THE ORGANIC PHASE. Mezyk, S.P. (1); Horne, G.P. (2); Mincher, B.J. (2), Cook, A.R (3). (1) California State University at Long Beach. (2) Idaho National Laboratory. (3) Brookhaven National Laboratory. The solvent-based reprocessing of used nuclear fuel is typically based upon mixed-phase extraction techniques, and utilizes designer ligands dissolved in an organic phase to extract ligand-complexed lanthanide/actinide metal ions from a highly acidic aqueous phase. Such extractions occur in a highly radioactive environment, and therefore an understanding of the radiation chemistry of these complexants and their diluents is vital in determining process extraction efficiency, separation factors, and solvent-recycle longevity. However, little fundamental kinetic and mechanistic data has been reported for the degradation of extraction ligands in the organic phase. The radiolysis of organic diluents (dodecane, TPH, kerosene) produces a mixture of radical cations (R•+), carbon-centered radicals (R•), organic solvated electrons (e-), and molecular products such as molecular hydrogen. Typically, the radical species and solvated electrons react with dissolved oxygen to produce peroxyl radicals, leaving the alkane radical cation species, R•+, as the major radiolytically-produced species that can react with, and degrade, extraction agents in this phase. Here we report on our kinetic studies for organic radical cation reactions with various nitrogen- and phosphorus- containing ligands (CMPO, TODGA, TBP, etc.), both free and complexed with lanthanide ions. Fast reaction rate constants were measured, stressing the importance of this mechanistic pathway. The ultimate goal is to combine these data with the known acidic aqueous phase chemistry to allow a full, fundamental, understanding of the impact of radiation on solvent extraction based separation processes.


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Log 385. SMALL, LOW-POWER ELECTROSTATIC PRECIPITATION AEROSOL COLLECTOR FOR FIELD EXPERIMENTS ON RADIONUCLIDE MONITORING. Keillor, M.E. (1); Burnett J.L. (1); Day, A.R. (1); Dion, M.P. (1); Miley, H.S. (1); Smart, J.E. (1). (1) Pacific Northwest National Laboratory. Measuring aerosol radionuclides is a Hanford Atomic Works heritage extending from effluent monitoring in the days of the Manhattan Project to research supporting national and international nuclear test treaty monitoring currently performed PNNL scientists and engineers. This capability has been useful for both environmental purposes and national security applications. Methods of concentrating aerosol radionuclides using filters, such as technology currently employed for treaty monitoring (1), consume significant power (e.g. 3 kW to process ~20,000 cubic meters of air per day). The power consumption is primarily driven by the airflow restriction of the filter media. We are researching the performance characteristics of small, low-power electrostatic precipitator-based aerosol samplers which would be useful for field studies of radionuclide releases. Such a sampler would provide a more geographically responsive radionuclide monitoring capability, complementing high-volume, fixed location samplers that cannot be relocated into the forecast effluent plume track. This concept has been around since at least the early 1960s, however is yet to be developed into an automated system for radionuclide monitoring. This work will present progress on a study of aerosol collection parameters in an electrostatic precipitator configuration suitable for automated aerosol sampling and subsequent radiometric measurement. [1] Miley et al. Journal of Radioanalytical and Nuclear Chemistry, Volume 235, Issue 1-2 (2006) DOI: 10.1007/BF02385942 Log 386. EXAMINING URANIUM CRM 124 ELEMENTAL HOMOGENEITY USING MICRO-X-RAY FLUORESCENCE. Worley, C.G. (1); Colletti, L.P. (1); Pacheco, S.D. (1); Tandon, L. (1). (1) Los Alamos National Laboratory. Certified Reference Materials (CRMs) are essential to nuclear material analysis and quantification. Using micro-X-ray fluorescence (MXRF) with an x-ray beam focused to ~30 microns, elemental homogeneity was directly imaged in the uranium elemental impurity CRM 124-3. As stated in the certificate of analysis, CRM 124 was carefully milled and blended to ensure elemental homogeneity over a macro scale. However, when micro analytical methods such as MXRF and scanning electron microscopy (SEM) are used, it is important to recognize that significant elemental heterogeneity could be present for the small specimen areas examined. Thus, MXRF was beneficial in directly imaging elemental inclusions present in the 10s of square millimeter regions of CRM 124-3 examined. At this small scale, heterogeneity was observed in the calcium, chromium, copper, iron, nickel, titanium, tungsten, and zinc MXRF elemental images. Most of these elemental impurities were added to U3O8 at 20 - 50 ppm to prepare CRM 124-3. Trace elements added at <10 ppm were generally not detectable with MXRF; although, if a particle containing a relatively higher concentration of an element with Z > 10 is present in the imaged area, it can be detected by MXRF. High resolution optical microscopy was also used to examine elemental inclusions located with MXRF to study particle features in greater detail than possible using the MXRF instrument camera.


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Log 387. INTEGRATION OF A HYPHENATED HPIC-ICPMS PROTOCOL FOR THE MEASUREMENT OF TRANSPLUTONIUM ISOTOPIC MASS DISTRIBUTIONS FOR Cf-252 CAMPAIGNS AT OAK RIDGE NATIONAL LABORATORY. Roach, B.D. (1); Giaquinto, J.M. (1); Keever, T.J. (1). (1)Oak Ridge National Laboratory. Rapid measurement of transplutonium isotopic mass distributions during Cf-252 production campaigns at Oak Ridge National Laboratory (ORNL) is a critical need. Mass measurements for the isotopes of americium, curium, californium, and berkelium are routinely requested to support the α-hydroxy-isobutyrate runs for the purification and recovery of the heavy curium target material and final Bk-249, Cf-252, and Es-254 enriched isotope products. Historically it has been challenging to achieve baseline resolution using the classical analytical gravimetric separation chemistries for these elements required to resolve isobaric overlaps and achieve accurate isotopic mass measurements. The Nuclear Analytical Chemistry and Isotopics Laboratories (NACIL) group within the Chemical Sciences Division has developed many novel rapid mass spectrometry protocols using hyphenated High Pressure Ion Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HPIC-ICPMS) to achieve baseline separations for elements across the periodic table. The advancement and integration of HPIC-ICPMS protocols into the suite of high level radiochemistry methods performed by the NACIL to support the production of heavy isotopes at ORNL has given the NACIL group a powerful analytical capability to provide rapid response during fast paced production campaigns to delivery these rare isotope products for research, medical, and commercial applications. Presented will be the integration of the HPIC-ICPMS technique and the protocol and chemistry that allows for rapid baseline separation and direct quantification of the transplutonium elements and isotopes. *Oak Ridge National Laboratory is managed by UT-Battelle for the Department of Energy under Contract DE-AC05-000R22725. This submission has been authored by a contractor of the U.S. Government under contract No. DE AC05-00OR22725. Accordingly, the U.S. Government retains a non-exclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for the U.S. Government purposes. Log 388. INVESTIGATION OF FISSILE MATERIALS COLLECTED FROM A NON-CRITICAL NUCLEAR EXPLOSION SITE USING NON-DESTRUCTIVE ANALYTICAL TECHNIQUES. Varshney, G. (1, 2); Cezeaux, J.R.(3); Petrosky, J.C.(1). (1) Department of Engineering Physics, Air Force Institute of Technology. (2) Oak Ridge Institute for Science and Education. (3) 711th Human Performance Wing, Air Force Research Laboratory. Investigation of nuclear materials and debris collected from critical and non-critical nuclear accidents is considered crucial in identifying the source, purpose of the nuclear materials’ origin and formation history. Key to this research is identifying, segregating, and characterizing “hot particles”, which carry a plethora of forensics information related to radiological, chemical, and metallurgical processes. It is postulated that a nuclear weapon accident that only involves a chemical detonation may produce contamination particles with morphologies and surface chemistry that are different from those created by other accident conditions, such as a fuel burn, and may provide insight into the accident analysis. In this work, we identify, isolate, and characterize hot particles from bulk soil samples collected from a non-critical nuclear detonation site. Several non-destructive techniques were used to identify and isolate the nuclear fuel particles from soil samples. Digital autoradiography was used to indicate and localize individual “hot particles”, while gamma spectroscopy was employed to quantify plutonium signatures. In addition, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to study the surface morphology and elemental composition of the hot particles. Initial sample analyses indicate that explosively dispersed non-critical fuel morphology may be substantially different from samples taken from other non-critical accident scenarios.


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Log 389. SYNTHESES OF TANNIC ACID-TYPE ORGANIC COMPOSITE ADSORBENTS FOR SIMULTANEOUS REMOVAL OF VARIOUS TYPES OF RADIONUCLIDES IN SEAWATER. Tachibana, Y. (1); Suzuki, T. (1); Nogami, M. (2); Nomura, M. (3); Kaneshiki, T. (3). (1) Nagaoka University of Technology. (2) Kindai University. (3) Tokyo Institute of Technology. Recently, we have successfully synthesized the tannic acid-type organic composite adsorbent for thesimultaneous removal of twelve kinds of radionuclides (Mn, Co, Sr, Y, Ru, Rh, Sb, Te, Cs, Ba, Eu, I) in seawater. This composite adsorbent (PA316TAS) is chemically combined with PA316, which is one of porous-type strongly basic anion-exchange resin with quaternary ammonium groups (PA316) and sulfonated tannic acid (TAS), which has the high adsorption ability for many kinds of metal ions and enough heat resistance. In the experiments using PA316TAS in seawater, we have discovered the sensational adsorption phenomenon of I species which cannot be confirmed in the individual adsorbent. Concretely, the saturation capacity per unit weight of adsorbent was much larger than any other that in previous reports. Moreover, the others such as Mn, Co, Sr, etc., have been effectively removed from seawater. In the severe accident at Fukushima, the conventional iron coprecipitation and carbonate precipitation methods have been mainly used for the simultaneous decontamination of radionuclides, generated by means of sustained injections of seawater and decontaminated water for emergency and constant cooling of nuclear cores. However, the large amounts of precipitation with radionuclides has been producing continuously. Hence, our chromatographic techniques using PA316TAS may be available for the simultaneous decontamination of radionuclides in severe accidents. In these contexts, we have examined the adsorption-desorption mechanisms of twelve kinds of radionuclides using PA316TAS in various types of original seawater and in the wide temperature range, considering the results of DV-Xá calculations of PA316, TAS, and PA316TAS. Log 390. SPECIATION IN MARINE RADIOECOLOGY USING COMPLEMENTARY SPECTROSCOPIC TECHNIQUES. Beccia, M.R. (1); Reeves, B. (1,6); Matara, A.M. (1,2); Maloubier, M. (1,7); Moisy, P. (3); Dumas, T. (3); Roques, J. (4); Solari, P.L. (5); Monfort, M. (6); Moulin, C. (6); Den Auwer, C. (1). (1) Université Côte d'Azur, CNRS, Institut de Chimie de Nice, France. (2) Laboratory of Radiochemistry, University of Helsinki, Finland. (3) Commissariat à l'Energie Atomique, France. (4) Université Paris Sud Orsay, France. (5) Synchrotron SOLEIL, MARS beam line, France. (6) Commissariat à l'Energie Atomique, France; (7) now: Department of Environmental Engineering and Earth Sciences, Clemson University. Dissemination mechansims of actinides resulting from accidental release in the environment, particularly in sea water, is a scientific but also political and social issues. Hence, the need for managing the risk, for controlling the environmental fate and transport, and for preventing human exposure through direct contact and indirectly through the food chain is essential. Among the different environmental matrices, seawater represents the largest proportion of the hydrosphere and covers by itself about 71% of the earth's surface. It is therefore crucial to attempt to perform direct speciation determination in seawater and to understand the transfer and accumulation mechanisms in marine species. In a first step we have address this question by doping natural seawater with actinide elements in order to be able to perform direct spectroscopic investigation and thus to decipher their molecular speciation. Our investigation of early actinide elements covers U, Np, Pu and Am at oxidation states spanning from +III (Am) to +VI (U). To do so, we have combined several spectroscopic techniques : X ray Abosption Spectroscopy, XAS; Time-Resolved Laser-Induced Fluorescence, TRLIF and Infra Red Spectroscopy, FT-IR together with speciation modeling and quantum chemical models. In a second step, we have investigated the uptake mechanisms of uranium by a model biomonitor, in vivo. We have selected sea urchins Paracentrotus Lividus known as a possible sentinel for heavy metal accumulation. The accumulation mass balance inside the sea urchin organs has been determined as well as the uranium speciation using XAS


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Log 391. CT IMAGE RESTORATION VIA DEEP LEARNING PRIORS. Sun, Y. (1); Zhao, Z. (1); Cong, P. (1); Li, L. (1); Guo, X. (1). (1) Tsinghua University. The reconstructed image quality of CT system may be degraded by various reasons such as quantum noise, scatter effect and sparse projection views. Although the deep convolutional networks have been proved an effective tool for CT image restoration, the most existing methods trained on a large datasets of corrupted image and ground truth pairs, which is highly problematic. In this work, we train a generator network to capture CT image statistics prior, which used for image restoration. Compared with the traditional methods, the proposed method doesn't require ground truth images for supervised training and suitable for different applications. The Experiments shows that the proposed method can effectively works for different CT restoration problems. Log 392. DEVELOPMENT OF FUNCTIONAL MEMBRANES FOR NUCLEAR FORENSICS. Husson, S.M. (1); Darge, A. (1); Duval, C.E. (1, 2); Wu, Y. (1); Watson, M. (1); Jacobsohn, L.G. (1); DeVol, T.A. (1). (1) Clemson University. (2) Current affiliation: Case Western Reserve University. This presentation will describe new materials and sample collection and concentration methods, combined with state-of-the-art analysis techniques for the identification and accurate quantification of the isotopic composition of special nuclear material. It will highlight our efforts to fabricate reactive, functional membranes as substrates for radiometric analyses. These substrates were prepared by grafting uranium- and plutonium-selective, polymeric ligands from the surface of ultrafiltration (UF) membranes. Samples for radiometric analyses were prepared by filtering U and Pu solutions through the UF membranes. We investigated the effects of membrane support properties and modification conditions on sample preparation time and peak resolution in alpha spectroscopy and conversion electron microscopy measurements. Conversion electron spectroscopy offers complimentary information relative to alpha spectroscopy in that it allows for quantification of SNM isotopes, such as Pu-239/240, without peak deconvolution techniques. In addition to providing excellent peak energy resolution, the membranes can process liters per hour of groundwater without pH adjustment using a portable UF cell at low pressure. A membrane loaded with SNM and further coated with scintillating quantum dots offers rapid quantitative assessment of the SNM. In this work, ZnS:Ag-the most efficient scintillator for alpha particle radiation-was prepared by solid state reaction and hydrothermal methods, and characterized in its microstructure, luminescence and scintillation. The results of this research are laying the foundation for the development of a rapid, field portable method for the separation and isotopic identification of waterborne SNM, which would be a powerful nuclear forensics tool. Log 393. ORGANIC- AND NITRATE-RADICAL REACTIONS WITH EXTRACTION LIGANDS IN THE ORGANIC PHASE. Gleason, J.M. (1); Mezyk, S.P. (1); Kiddle, J.J. (2). (1) California State University at Long Beach. (2) Western Michigan University. For the hydrometallurgical recovery of actinides from mixtures of dissolved used nuclear fuel the damaging effect of radiolysis is of major concern. The deposition of the energy of radioactive decay in matter produces highly reactive free radicals and all components of any solvent-extraction based operating recovery process are at risk from such damaging reactivity. It is therefore of utmost importance that quantitative control of free radical chemistry exists prior to any serious consideration of technological deployment of a process designed to recover minor actinides. While considerable research has been reported on the kinetics and performance impacts of radiation-induced ligand damage for acidic water radiolysis species far less is known about the equivalent in the organic phase. The organic phase in a typical liquid-liquid extraction system uses normal alkanes such as dodecane as diluent, and radiolysis results in a mixture of carbon-centered radicals, solvated electrons, and (when in contact with acidic water) nitrate radicals being formed. The presence of dissolved oxygen is usually assumed to scavenge the carbon-centered radicals and electrons, however, the high concentrations of added ligands to the organic phase means that some reaction of these species with the ligands will occur. In this work, we report on our preliminary kinetic measurements of these three radicals with typical extraction ligands. The carbon-centered radicals were generated by laser flash photolysis of synthesized dialkylazo species, and the nitrate radicals by electron pulse radiolysis of mixed organic phases.


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Log 394. INTERPRETING 230Th/234U AND 231Pa/235U AGES IN URANIUM OXIDES AND METALS. Kayzar-Boggs, T.M. (1), Denton, J.S. (1), Wende, A.M. (1), Yost D.G. (1), Kinman, W.S. (1). (1) Los Alamos National Laboratory An important nuclear forensic signature that can support the investigation of nuclear or other radioactive material out of regulatory control is a material's "model age" determined through radiochronometry. Radiochronometry involves the careful measurement of radioactive nuclides or "parent" isotopes and their decay progeny referred to as "daughters" in order to calculate the time that has passed since a material was last purified. For uranium materials, two common chronometers are used to determine model ages: 230Th/234U and 231Pa/235U (daughter product/parent nuclide). Any calculated model age is dependent upon assumptions. One such assumption being that at the time the material was produced, all daughter products were completely purified. This assumption is generally supported by age dates of well-characterized uranium oxide materials such as certified reference materials. However, the assumption that all daughter products are removed during production may not be valid during the casting of uranium metals. Here, we compare and contrast 230Th/234U and 231Pa/235U model ages for U3O8, UO3, and uranium metal materials. We will discuss the challenges associated with interpreting radiochronometry signatures, and will suggest future paths forward for radiochronometry research. Log 395. CESIUM CONTAMINATION IN FUKUSHIMA, JAPAN: A COMPARATIVE ANALYSIS OF DOSE CHANGES AND MEASUREMENT TECHNIQUES. Seel, P.J. (1); Shozugawa, K. (2); Hori, M. (2); Motoyuki, M. (2); Sudowe, R. (1). (1) Colorado State University, Department of Environmental & Radiological Health Sciences. (2) University of Tokyo, Graduate School of Arts and Sciences. Radioactive Cs-137 and Cs-134 are the radioisotopes of primary environmental concern still remaining after the 2011 accident at the Fukushima Dai-ichi Nuclear Power Plant. Air dose measurements and calculations have been maintained by the government, but further description of the dispersion and movement of radiocesium in the region would benefit scientists and former residents. Contemporary descriptions of the changes in regional radioactivity would help inform the return of Japanese citizens to the area. Local remote radiation monitors and vehicle-based surveys help to show the impact of weather effects on distribution of radiocesium compounds, but show only a of portion of the spatial variability. Comparing the resolution and efficacy of these techniques and geospatial analysis provides a means of determining best practices for radiation monitoring in the region and determining accurate timelines for the reduction of dose to levels acceptable to the public. However, challenges exist in finding generalizable dose rates in a heterogenous environment and accurately correcting the measured dose rates to the geometry and shielding present in the field. Results have found nearly double the expected loss of these isotopes from the environment assuming only nuclear decay, showing that there are significant alternate pathways for the removal of cesium from the region.


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Log 396. FORMATION MECHANISMS OF NOBLE METAL PARTICLES (EPSILON PHASE) IN IRRADIATED OXIDE FUEL. Clark, R.A. (1); Devanathan, R. (1); Buck, E.C. (1); Conroy, M.A. (1); Droubay, T.C. (1); Garrett, K.E. (1); Jiang, W. (1); Kessler, S.H. (1); Krogstad, E.J. (1); Kruska, K. (1); Lach, T.G. (1); Overman, N.R. (1); Pellegrini, K.L. (1); Schwantes, J.M. (1); Shen, S.D. (1); Soderquist, C.Z. (1). (1) Pacific Northwest National Laboratory. The chemical fractionation of five-metal “epsilon phases” from nuclear fuel under irradiation is a process that is not well understood. The development of these phases within uranium oxide matrices over time in fuel under irradiation has been linked to many important phenomena over the life cycle of nuclear fuel, from in-reactor operations to long-term spent fuel disposition. In order to elucidate the physical and chemical mechanisms that govern the formation of these inclusions in irradiated fuel, we have studied conditions leading to their formation and unique properties in both irradiated uranium fuel and in surrogate material. We have used ion implantation of ceria (a surrogate of urania) doped with Mo, Pd, Ru, Rh and Re to understand fundamental mechanisms of metallic nanoparticle formation in an irradiated ceramic. Our results reveal stages in nanoparticle aggregation and point to the key role of irradiation-enhanced diffusion at temperatures below about 700°C. In studies of irradiated uranium fuel, isotopic analysis was performed with separated particles from three Advanced Test Material (ATM) sources. These studies revealed pathway mechanisms of elements as well as providing evidence for a significant sixth metal. Microscopy studies of a cross section of irradiated fuel provided clues to formation and transport mechanisms within the fuel pellet. Log 398. APPLYING ARES METHODS TO AMS FOR IMPROVED RADIOLOGICAL MAPPING IN COMPLEX TOPOGRAPHIES. Quiter, B.J. (1); Joshi, T.H. (1); Suzuki, E. (1); Bandstra, M.S. (1). (1) Lawrence Berkeley National Laboratory. The US DOE Aerial Measuring System (AMS) provides a means of rapidly mapping radiological contamination in the event of a radiological emergency. One known challenge for AMS missions that historically data products relied on the assumption that measurements were made above a flat plane in order to determine dose rates on the ground from measured radiological signatures. Measurements in mountainous terrain made in response to the Fukushima nuclear incident highlighted shortcomings of this method. We will demonstrate, using regularized Maximum Likelihood-Expectation Maximization methods developed for the Airborne Radiological Enhanced-sensor System (ARES) Advanced Technology Demonstration, how airborne radiological measurements analyzed in conjunction with topographic databases can be applied to AMS radiation detector systems. We will then leverage ARES data and methods to assess whether operating an INS or reading out the AMS detector system using more channels could provide additional benefit to producing radiological contamination maps.


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Log 399. STATE-OF-THE-ART SYNCHROTRON-BASED TECHNIQUES AND ANALYTICAL APPROACHES FOR THE UNDERSTANDING OF RADIONUCLIDE UPTAKE MECHANISMS BY CEMENT. Vespa, M. (1); Dähn, R. (2); Wieland, E. (2). (1) Geochemical and Environmental Consulting, Germany. (2) Paul Scherrer Institute, Laboratory for Waste Management, Switzerland. Synergetic use of state-of-the art synchrotron-based measurement techniques from the macro- down to the nano-scale and analytical methods together with laboratory techniques are a unique approach to determine uptake processes of radionuclides onto cementitious materials. Cement is foreseen in many countries as an engineered barrier within the concept of the geological disposal for radioactive waste. Furthermore, cement is a highly heterogeneous material with reacting phases down to the nanometer scale. Investigations on the uptake of cobalt onto cement using X-ray absorption spectroscopy and scanning transmission X-ray microscopy revealed that at the macro- to micro-scale Co3+ and Co2+ hydroxide were the predominant phases, whereas on the nano-scale the formation of an additional phase, the Co2+ phyllosilicate, played a significant role. Contrarily to Co, nickel forms preferentially layered double hydroxides phases. Indeed, radionuclides with the same oxidation state do not necessarily show similar uptake mechanism and often minor cement phases are involved. In many cases, not the major phases, but the minor phases are the solubility limiting factor driving the radionuclide uptake process. Further investigations have shown that cement, when in contact with clay, can interact forming semi-amorphous magnesium rich phases. The structure of these phases was elucidated by using a combination of X-ray near-edge spectroscopy and state-of-the-art ab initio calculations. The results indicated a layered structure of the phases composed of tetrahedral-octahedral-tetrahedral layers and an interlayer of Mg-hydroxides. Log 400. DETERMINATION OF ALUMINUM IN BOVINE LIVER SRM 1577C BY COLD-NEUTRON ACTIVATION ANALYSIS. Zeisler R.L. U (1); Turkoglu D.J. (1). (1) National Institute of Standards and Technology. Although aluminum has no known biological function, the element has been controversially implicated as a factor in Alzheimer's disease. Therefore, its determination is commonly considered in NIST biological SRMs that serve diagnostic, nutritional, and toxicological measurements in medical, veterinary, and environmental sciences. Unfortunately, the Al mass fraction eluded certification in the newly-prepared bovine liver tissue SRM 1577c due to the lack of independent measurements by instrumental neutron activation analysis (INAA) for value assignment. The approaches with direct INAA failed because of interfering reactions with P and the inability to quantitatively control the pre-separation INAA. While INAA with cold neutron beams avoids the direct interference from P, the first demonstration at the FRM-II cold-neutron prompt gamma activation analysis (CNGPAA) station suffered from high Al-28 background. With the recent implementation of a high-efficiency detector array near the NIST CNPGAA station, a sufficiently-effective cold-neutron activation analysis (CNAA) procedure was developed in this work. Irradiations were carried out with 20 mm diameter, 700 mg sample pellets of bovine liver and multi-element standards on filter paper contained in clean thin-film polyethylene (PE) bags. These were positioned on the upstream side of Ti-foil flux monitors at the beam entrance port to the CNPGAA sample chamber. After precisely-timed irradiations for 300 s, samples were transferred to unirradiated PE bags and counted in the dual-detector spectrometer. Mass fraction values of Al as well as of Cu and Mn as quality control elements were determined in samples of the Bovine Liver SRM series.


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Log 401. MOLYBDENUM ISOTOPE COMPOSITION OF NUCLEAR MATERIALS: METHODOLOGY AND RESULTS FROM URANIUM ORE CONCENTRATES. Rolison, J.M. (1); Druce, M.(1). (1) Nuclear and Chemical Sciences Division, LLNL. The broad objectives of nuclear forensic investigations are to determine the origin, history, and intended or potential use of nuclear material discovered to be outside of regulatory control. Modern analytical techniques that have been largely developed in the field of Earth and Planetary Science are being adapted to investigate chemical and isotopic tracers of processes related to nuclear materials in an effort to meet these objectives. Here we report on recent developments in establishing methods for accurate and precise analysis of molybdenum (Mo) isotope ratios in nuclear materials. Complete separation of Mo from uranium (U) during the production of uranium ore concentrate (UOC) is generally not achieved and, like U, Mo forms a hexafluoride gas. Thus, during the production of UOC and subsequent conversion to UF6 and enrichment, traces of Mo from the ore body will remain in the final uranium products. Fractionation of Mo isotopes during the different processing steps within the nuclear fuel cycle may result in characteristic signatures that could be exploited to aide in meeting the nuclear forensic objectives, but it is necessary to quantify the range of Mo isotope compositions within a variety of UOC samples to establish a baseline to which other materials can be compared. Here we demonstrate that a variety of UOC samples have limited Mo isotope compositions consistent with the range observed in natural materials. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was supported by the LLNL-LDRD Program under Project No. 18-ERD-016. LLNL-ABS-743267 Log 402. ADVANCED CORRELATION NEUTRON COUNTING FOR NUCLEAR SAFEGUARDS. Nicholson, A.D. (1); Worrall, L.G. (1); Britton, C.L. (1);Croft, S. (1); Dayman, K.J. (1); Ericson, M.N. (1); Simone, A.C. (1). (1) Oak Ridge National Laboratory. In nuclear safeguards, verifying fuel pin loading patterns and partial defect detection in fresh fuel assemblies using neutron non-destructive assay systems is a challenge. Currently, neutron collars, employing 18 or more 3He neutron detectors, are used to verify 235U linear mass density in fresh fuel assemblies. These units derive neutron multiplicity rates from a single pulse train from all detectors. In this work, a neutron coincidence counter currently used in safeguards measurements, the Mirion JCC-71, is retrofitted with new electronics to enable the analysis of list mode pulse trains from all neutron detectors. These pulse trains are analyzed to derive detector network multiplicity rates and spatial information on fuel pin loading. The goal of this research is to explore the efficacy of upgrading existing systems with new software and hardware in detecting nuclear material diversion and partial defect scenarios. Log 404. QUANTIFICATION OF U, Pu, AND Cs ISOTOPE RATIOS FROM SPENT NUCLEAR FUEL BY RESONANCE IONIZATION MASS SPECTROMETRY. Isselhardt, B.H. (1); Savina, M.R. (1); Trappitsch, R.G. (1). (1) Lawrence Livermore National Laboratory. We have demonstrated the unique ability of Resonance Ionization Mass Spectrometry (RIMS) to accurately quantify uranium, plutonium, and cesium isotope ratios from the same volume of spent nuclear fuel in situ using a two-step measurement process. This was demonstrated in samples deposited from solution and solid samples of spent nuclear fuel. RIMS measurements of the U-235/U-238 and Pu-240/Pu-239 isotope ratios agreed with known values with uncertainties <1% RSD, minor isotopes also agreed with known values within statistics limited uncertainties, except for Pu-238 and Pu-241. Multi-element isotope ratio analysis by RIMS is accomplished by beginning a measurement at very low laser desorption power, such that only volatile species are removed from the sample while the voltage normally used to reject secondary ions is off. This produces abundant Cs secondary ions without removing a significant fraction of actinides or isobars for Cs. Next, after the Cs ions are counted to sufficient precision (0.5% RSD), the secondary ion rejection voltage is turned on and the laser desorption power is increased until the desired desorption rate for the actinides is achieved. Under these conditions, U and Pu isotopes can be efficiently measured simultaneously by RIMS because they are each ionized by different sets of resonantly tuned lasers. U atoms are ionized first and the ionization of Pu is delayed by about 400 nanoseconds so that ions produced by the lasers responsible for ionizing Pu will arrive at a time corresponding to 1.5 mass units heavier than ions produced by the U lasers.


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Log 405. EVALUATION OF THE SOLUBILITY OF Be-7 PARTICLES IN SIMULATED LUNG FLUID. Aviv, O. (1); Sasson, R. (1); Spitz, H.B. (2); Halfon, S. (1); Yungrais, Z. (1); Daniely, E. (1). (1) Soreq Nuclear Research Center, Israel. (2) University of Cincinnati. During preparations for an experiment to be conducted in the Soreq Applied Research Accelerator Facility (SARAF) at Soreq Nuclear Research Center, a target containing approximately 10 GBq of 7Be was damaged releasing particles into the room that subsequently were inhaled by a small group of workers (Aviv et al., 2017). Removal of inhaled particles was studied in one of the exposed workers by performing a series of direct (in vivo) and indirect (urinalysis) bioassay measurements over time. Results of the in vivo measurements over a period of 108 days demonstrate that retention of 7Be in the respiratory tract can be described using a two-component exponential function with half-lives of ~0.4 days and ~109 days. Information provided by the target manufacturer (Maugeri et al., 2017) suggests that the particles in the source are beryllium hydroxide (Be(OH)2), which is only slightly soluble in water. However, results of direct, in vivo measurements suggest that most of the activity was rapidly removed from the respiratory tract. Samples of 7Be particles swiped from the damaged target were dissolved in simulated lung fluid and measured over time using an HPGe detector to evaluate solubility in vitro. Rapid (< 1 day) dissolution of the 7Be particles measured in vitro is consistent with rapid removal from the respiratory tract as measured in vivo. The methods used for determining the solubility will be presented, as well as detailed results. Log 407. IN SITU QUANTITATIVE ANALYSIS OF NON-PERTECHNETATE Tc-99 IN HANFORD TANK WASTE. Branch, S.D. (1, 2); French, A.D. (1); Lines, A.M. (1); Soderquist, C.Z. (1); Rapko, B.M. (1); Heineman, W.R. (2); Bryan, S.A. (1). (1) Pacific Northwest Laboratory. (2) University of Cincinnati. A method was developed for the in situ spectroscopic analysis of non-pertechnetate [Tc(CO)3]+ in a real waste sample from tank 241-AN-102 at the Hanford Site in southeastern Washington. The real waste samples were introduced to a developer solution which converts the non-emissive [Tc(CO)3]+ species into a luminescent complex by binding with a bidentate sensitizing ligand. After complexing with a sensitizing ligand, the [Tc(CO)3]+ species has a spectroscopic signature that is able to be distinguished from other constituents within the waste sample. The [Tc(CO)3]+ is then quantified within the sample using a standard addition method. This conversion technique is based on a test method demonstrated using [Re(CO)3]+ analogues in simulated waste samples. A sample was received from tank 241-AN-102 at the Hanford Site, of which three sample fractions were tested for [Tc(CO)3]+ concentration: (1) a 5 M sodium adjusted sample fraction (9.90E-6 M); a fraction depleted of Cs-137 via an ion exchange process (0 M); and an acid-stripped column eluate fraction (2.46E-6 M). The concentration of [Tc(CO)3]+ in the original AN-102 waste supernatant was determined to be 1.84E-5 M.


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Log 408. RARE EARTH ELEMENT INTERACTIONS WITH URANIUM DIOXIDE. Carter, R.A. (1); Sutter, S.M. (1); Hixon, A.E. (1). (1) University of Notre Dame. Elemental analysis and characterization of surface morphologies and microstructures of nuclear materials have been applied to complement isotopic analysis for both nuclear proliferation and nuclear smuggling activities. However, none of the collected samples are in their pristine condition; for example, they will have aged due to interactions with the surrounding environment. Deciphering the aging processes of complex nuclear materials in various environments is crucial for understanding the changes these materials have experienced from the time of their production and use to the time of sample collection. In particular, studying the diffusion of trace elements into and out of solid-phase nuclear materials in contact with water under different aging scenarios may lead to the identification of definitive aging signatures. As a first step, we used batch sorption experiments to investigate the interactions of twelve REEs (i.e., La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb) in aqueous solution with uranium dioxide as a function of pH (i.e., 3-9), ionic strength (i.e., 0.025 - 0.5 M), REE concentration (i.e., 4 - 8.33 ppm), and UO2 concentration (i.e., 5 - 50 g/L). Aqueous phase concentrations of the REEs were determined using inductively coupled plasma mass spectrometry (ICP-MS) and the morphology of UO2 was examined using scanning electron microscopy (SEM). Results were in line with typical cation sorption behavior wherein sorption increased with increasing pH and decreased with increasing ionic strength. Preferential sorption of lighter REEs was observed. Varying REE and UO2

concentrations had little effect on sorption behavior. Log 410. ATMOSPHERIC DEPOSITION OF Be-7 IN ROMANIA. Dovlete, C. (1); Osvath, I. (2); Sonoc, S. (3). (1) Independent researcher. (2) IAEA Environment Laboratories. (3) University of Toronto. Most published studies describe the specific activity of Be-7 in surface air and/or deposition at a single or a few sampling stations. This extensive study is based on 28 stations from Romanian's NERSN network (National Environmental Radioactivity Surveillance Network), with different geographical and climatological conditions over the period 1978-1994. Total-deposition samples were collected on a daily basis at each station of the network and cumulated monthly for gamma spectrometric measurements according to a well-established common methodology. All measurements were performed at the Environmental Radioactivity Laboratory in Bucharest Afumati. The annual mean bulk (combined wet and dry) depositional fluxes of atmospheric Be-7 varied between 253 and 1093 Bq m.2 y.1 and this variability was attributed mainly to the amount of precipitation and the geographical variations of the atmospheric concentrations of Be-7. The mean monthly atmospheric depositions of Be-7 showed a strong seasonal trend with the highest values being observed in the spring/summer and the lowest in the winter period. Results regarding multiannual monthly mean deposition fluxes (separately wet and dry) are presented and discussed for 2 contrasting stations. The dependence of Be-7 activity with the sunspot number is also confirmed from the experimental data. Log 411. DETERMINATION OF THE INGROWTH CORRECTION FACTOR FOR GAS FLOW PROPORTIONAL COUNTING OF CHEMICALLY SEPARATED SAMPLES WITH A RADIOACTIVE PROGENY. Eder, R.M. (1). (1) Air Force Technical Applications Center. Gas flow proportional counting of chemically separated radioactive samples frequently requires efficiency correction factors to correct for the influence of a radioactive daughter during the count. As the radioactive analyte of interest decays into a radioactive daughter, the radioactive daughter decays contribute to the total count. The daughter radionuclide typically has a distinct counting efficiency which must be determined separately from the parent. Additionally the ingrowth ratio (ratio of daughter to parent activity) must be known to accurately correct the daughters influence on the total count. Typically this ingrowth ratio has been calculated at the midpoint of the count to represent an average ingrowth contribution to the count rate (i.e. ASTM D5811 Standard Test Method for Sr-90 in water) but this approximation can cause a bias on the order of several percent, especially for radionuclides whose ingrowth ratios change significantly during the count. The true ingrowth ratio of the daughter to the parent has been calculated from the number of granddaughter progeny produced during the count divided by the number of parent decays during the count. Derivation of this factor, by equation substitution, is explained and its results are compared to an integration method.


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Log 412. PRODUCTION AND STANDARDIZATION OF AN ON DEMAND Pa-233 TRACER. Galea, R. (1); Moore, K. (1); Armstrong, A. (2); Naperstkow, Z. (1). (1) National Research Council of Canada. (2) McMaster Nuclear Reactor. Uranium radiochronometry is of great interest for the nuclear forensics and geochronometry communities as it enables the direct calculation of the separation age of enriched U-235. Radiochronometric pairs U-234-Th-230 and U-235-Pa-231 and their concordance or discordance in age determination can furtermore provide information on the processing of the material in question. Accurate dating for both forensics and geochemistry require accurate standards against which instrumentation can be calibrated. The measurement of Pa-231 using atom counting methods requires a tracer of Pa-233 to determine correction factors such as mass bias or used as a tracer to evaluate or develop radiochemical separation schemes. Pa-233 can be produced from the milking of legacy Np-237 sources but Canada has evaluated the production of Pa-233 from the neutron activation of Th-232 and subsequent chemical separation. The samples were processed without the use of hydofluoric acid and eluted with hydrochloric acid. Absolute activity standardization was performed via four independent methods which were all in agreement within their associated uncertainties. The standard was then used to calibrate a secondary ionization chamber resulting in a rapid and traceable method for the production of a Pa-233 tracer. This standardization campaign was compared to that of a material from a traditional Np-237 daughter source contained in nitric and hydrofluoric acid. Differences in the radiochemistries with respect to the effect on standardization and storage in glass flame sealed ampoules will be presented. Log 413. PRODUCTION OF RADIOXENON AND RADIOARGON SOURCES FOR USE IN EXPERIMENTAL SIMULATION OF GAS RELEASE FROM AN UNDERGROUND NUCLEAR TEST. Haas, D.A. (1, 3); Biegalski, S.R. (1, 2); Artnak, E.J. (1); Klingberg, F. (1, 4), Tipping, T.N. (1); Bowyer, T.W. (3); Hayes, J.C. (3); Lowrey, J.D. (3), McIntyre, J.I. (3); Olsen, K.B. (3). (1) The University of Texas at Austin. (2) Georgia Tech University. (3) Pacific Northwest National Laboratory. (4) Comprehensive Nuclear-Test-Ban Treaty Organization. Detection of noble gas fission and activation products resulting from underground nuclear tests is a key component of nuclear explosion monitoring. Radioxenon and radioargon gases may reach the surface through several mechanisms, each with a characteristic timeline. In order to provide empirical data on these various mechanisms, a series of tests have been carried out at the Nevada National Security Site (NNSS). These tests released tracer gases underground and require the production of operationally significant levels of radioxenon and radioargon - up to TBq. Results include the method of producing these gases through the irradiation of specially prepared targets and models and experimental results of the activity produced. Log 414. A PAIR OF COMPLEMENTARY FAST NEUTRON EXPERIMENT FACILITIES AT A RESEARCH REACTOR. Haas, D.A. (1); Artnak, E.J. (1); Barron, D.C. (1); De Luna, B. (1); Pasman, M.E. (1). (1) The University of Texas at Austin. Two complementary fast neutron irradiation facilities have been designed and modeled in MCNP for use at the TRIGA Mark-II reactor at The University of Texas at Austin. These facilities will provide the capability to irradiate samples with fast neutrons and allow counting from under one second to days after irradiation. While many facilities provide the ability to irradiate samples with fast neutrons for material damage studies, few allow for analysis of samples so rapidly after irradiation. This presentation will describe the work on both the in-core irradiation facility with pneumatic transfer and beam line facility described in separate poster sessions. Both facilities have been designed to irradiate samples with ratios of fast to epithermal/thermal neutrons greater than 104, with flux values of 3x109 and 1x1011 n/cm2/s for the beam and in-core facilities, respectively. The design of these facilities uses a layered approach to capture thermal and then epithermal neutrons from the reactor while limiting materials near the samples that would thermalize the neutron spectrum. Sensitivity studies were performed in MCNP to optimize the design to minimize expensive materials while ensuring effective neutron spectrum tailoring in the limited geometries. The neutron flux to the sample modeled for each facility closely resembles the 235U Watt fission spectrum with a slight elevation in the epithermal neutron flux.


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Log 415. TASK-SPECIFIC IONIC LIQUIDS-PATHS TO IMPROVED RADIONUCLIDE SEPARATIONS. Hawkins, C.A. (1); Ferry, A.J. (1); Dietz, M.L. (2). (1) Tennessee Tech University, Department of Chemistry. (2) University of Wisconsin-Milwaukee, Department of Chemistry and Biochemistry. Task-specific ionic liquids (TSILs) are an increasingly important sub-class of ionic liquids (ILs) consisting of a conventional IL to which is affixed a functional group chosen to impart the solvent with specific physicochemical, catalytic, or solute-binding properties. As in numerous areas of investigation involving ionic liquids, the study of the synthesis, characterization, and application of TSILs has experienced explosive growth in the last 15 years. Since the first report of a TSIL incorporating a metal ion complexing group by Visser et al. in 2001, substantial effort has been directed toward TSIL application in the separation and preconcentration of metal ions. Indeed, representative examples of nearly all extractant families of current interest, particularly for actinide and fission product separations, have been employed as the active functional group of a TSIL. Among the aims of metal ion partitioning systems employing TSILs (w.r.t. molecular solvents) are to (i) provide “tunable” solvent extraction systems, (ii) substantially increase extractant solubility (essential to theoretical limits), and (iii) provide improved selectivity and/or higher extraction efficiency than possible with systems comprising an analogous extractant in an IL or an ordinary molecular solvent. In this talk, we highlight a number of the accomplishments, thus far, and seek to identify worthwhile directions toward improved radionuclide separations using TSILs. Recent results from our labs, exploring the synthesis and characterization of TSILs comprising dipicolinate salts of pnictogenium cations, will be discussed. Log 416. SYNTHESIS AND CHARACTERIZATION OF HOMOGENEOUS GLASS ANALOGS FOR SOLID DEBRIS MATERIAL. Moore, N.A. (1); Carter, R.A. (1); Dorais, C. (1); Hixon, A.E. (1). (1) University of Notre Dame. Following a nuclear detonation, radiochemists and post-detonation debris diagnosticians are tasked with performing high-quality analysis of fallout debris samples and accurate device interpretation. Debris formed following a nuclear detonation commonly consists of a heterogeneous glassy matrix containing uranium, plutonium, fission/activation products, and components of the surrounding urban environment. Homogeneous and well-characterized reference materials are critical for accurate post-detonation debris analysis. The goal of this research was to synthesize a homogeneous glass analog for solid fallout debris which contains uranium, surrogate fission products (e.g., Sr, Cs, Nd, Zr) and urban materials (e.g., Ca, Fe, Al). Two separate approaches were used to synthesize the glass analogs. The first approach is a modification of the sol-gel technique whereas the second approach involves heating doped metal oxides to 1000 C and quenching on a stainless steel plate in air. The morphology of the synthesized materials was examined using scanning electron microscopy (SEM), major element analysis and composition was determined using micro X-ray fluorescence (µ-XRF) and electron microprobe (EMP), and trace element analysis was determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) or secondary ion mass spectrometry (SIMS). The metric of homogeneity on a mesoscopic scale (i.e., hundreds to thousands of nanometers) was achieved. Future work is focused on the separation of uranium and other key components from the glass matrix using a volatility-based approach.


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Log 417. IDENTIFYING SURFACE MORPHOLOGICAL CHARACTERISTICS FOR QUANTITATIVE DIFFERENTIATION OF U3O8 MIXTURES SYNTHESIZED FROM URANYL PEROXIDE AND AMMONIUM DIURANATE. Heffernan, S. (1); McDonald, L.W. IV (1). (1) University of Utah Department of Environmental Engineering - Nuclear Engineering. Quantitative morphological analysis was recently utilized to prove statistical differences in the particle circularity and surface area of am-UO3 and U3O8 which were both synthesized using the uranyl peroxide route. While this signature adds a new dimension to nuclear forensics analysis, other techniques, namely powder X-ray diffractometry (p-XRD), can also show that distinction. However, if multiple routes are used to make solely U3O8, then p-XRD can no longer provide distinction between the mixed samples. Hence, an additional forensics signature is needed. In this instance, quantitative morphological analysis provides that needed signature. In the present study, surface morphological differences of mixtures of U3O8, synthesized from uranyl peroxide (UO4) and ammonium diuranate (ADU), was investigated using scanning electron microscopy (SEM). The purity of each sample was verified using p-XRD and SEM images were collected of each sample, individually. The U3O8 samples were then mixed in known quantities using a vortex mixer. Several hundred SEM images were collected of the mixed samples and the Morphological Analysis of Materials (MAMA) software was used to segment the discrete particles. Using the starting morphologies as a reference to identify the U3O8 from each synthetic route, the amount of U3O8 in each sample could be quantified to matching the known mixed values. This provides a method for identifying mixtures of uranium oxides derived from different synthetic routes when p-XRD data shows no discernible difference. Log 418. RADIOCARBON IN ATMOSPHERIC CARBON DIOXIDE AROUND NUCLEAR POWER PLANTS IN SLOVAKIA. Kontuľ, I. (1); Povinec, P.P. (1); Šivo, A.(1); Richtáriková, M. (1); Ješkovský, M. (1); Kaizer, J. (1); Čech, P. (2). (1) Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Slovakia. (2) State Geological Institute of Dionýz Štúr, Bratislava, Slovakia. Nuclear power plants are important sources of anthropogenic radiocarbon in Slovakia and therefore its content in the atmosphere and biosphere has been part of the monitoring program since 1968. A regular monthly sampling of radiocarbon in atmospheric carbon dioxide started in 1987 for the Jaslovské Bohunice nuclear power plant (NPP) at .lkovce sampling station, and in 2015 for the Mochovce NPP at Tajn monitoring station. A comparison of radiocarbon data sets with clean air data from Jungfraujoch clearly shows an excess of radiocarbon in the atmosphere as a consequence of radiocarbon releases from the NPPs. The record from .lkovce suggests that the releases from Bohunice NPP declined from relatively high maxima at the beginning of the record to small excess of radiocarbon in recent years where the radiocarbon concentration is much closer to the clean air background. The presence of very deep winter minima in the period up to 1995 suggested a strong influence of local and regional fossil carbon dioxide emission sources. This dilution effect has been significantly attenuated in the following years as a result of new cleaner industrial technologies applied in the SW Slovakia. Radiocarbon activity in the atmospheric samples from Tajn sampling station is very similar to the .lkovce one as it doesn't exhibit systematically higher radiocarbon excess in the available record. Radiation doses to public due to radiocarbon releases from Slovak NPPs have been negligible.


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Log 419. SOFT N- AND S-DONOR LIGANDS FOR ACTINIDE/LANTHANIDE SEPARATION AND FOR SENSING APPLICATIONS. Lehman-Andino, I. (1); Jonah, T.M. (1); Papathanasiou, K.E. (1); Dares, C.J. (1); Kavallieratos, K. (1). (1) Florida International University, Dept. of Chemistry and Biochemistry. Minor actinides in used nuclear fuel are responsible for much of the radiotoxicity and heat generation that limit the capacity of geological repositories. Actinide(An)/Lanthanide(Ln) separation processes via selective complexation and solvent extraction by synthetic ligands have to overcome difficulties due to their similarity in the +3 oxidation state in terms of ionic radii and general bonding characteristics. Designed extractants with soft S-donor and N-donor sites can take advantage of the slightly higher covalent character and differences in relative hardness of An(III) vs Ln(III) leading to potentially stronger extraction and selective separations. In this work we synthesized ligand families based on two main frameworks that allow straightforward incorporation of relatively softer thioamide, pyridine, and pyrazole sites: 1) 1,3,5-trisaminoethylbenzene and 2) dipicolinic acid. These frameworks allowed a comparative study of binding and extraction differences between ligands that contain the C=O vs. the C=S group. For example, while the O- donor dipicolinamide was shown to bind Ln(III) by UV-Vis and NMR in acetonitrile, the S-donor dithiopicolinamide ligand did not show any binding towards Ln(III). Yet the same dithiopicolinamide was shown to extract Am(III) vs. Eu(III) selectively from highly acidic solutions. Gas-phase studies and theoretical DFT calculations both showed stronger binding of An(III) vs. Ln(III) for the thioamide vs. amide ligand in agreement with preliminary extraction results. Furthermore, pyrazole ligands that contain varying substitution patterns showed remarkable differences in Ln(III) complexation and fluorescence sensing capabilities, which show some variation along the Ln(III) series. Log 420. VIRTUAL TEST BEDS FOR RADIATION DETECTOR AND ALGORITHM DEVELOPMENT. Nicholson, A.D. (1); Archer, D.E. (1); Bandstra, M.S. (2); Davidson, G.G. (1);Garishvili, I. (1); Peplow, D.E. (1); Mclean, M.S.L. (3); Ray, R.R. (1); Stewart, I.R. (1); Swinney, M.W .(1); Willis, M.J. (1); Quiter, B.J. (3). (1) Oak Ridge National Laboratory. (2) Remote System Laboratory. (3) Lawrence Berkeley National Laboratory. A large-scale virtual testbed, and the necessary supporting tools, have been constructed for radiation detector and algorithm development. Using LiDAR, camera or satellite data, point clouds of terrain, building profiles, and vegetation, are converted to computer-aided design geometries that can be read by 3-D Monte Carlo particle transport codes. Monte Carlo background source terms are informed using a library of experimental measurements. In addition, threat sources can be injected into the model for arbitrary source-shielding configurations. Gamma-ray flux is tallied over a 3-D mesh and can be saved separately for each material. Next, the gamma-ray flux mesh is convolved with a detector response function to calculate detector response at all locations in the model. Using Poisson statistics and a selected detector path and speed, calculated detector responses are down sampled to create list mode datasets for detector and algorithm evaluation. This methodology for generating virtual test beds has been validated at the Fort Indiantown Gap Facility in Pennsylvania and is being implemented in new and more complex environments. The goal of this work is to provide a benchmark dataset to study the performance of physics based and machine learning radiation detection algorithms. Generating data synthetically is much faster and cheaper to generate than large experimental campaigns. In addition, one has absolute knowledge (or total ground truth) of the virtual experiments and can alter systematics (such as background composition, magnitude, source shielding and activity) to probe detector and algorithm response.


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Log 421. IAEA SUPPORT TO THE QUALITY ASSURANCE OF JAPAN'S MARINE MONITORING PROJECT. Osvath, I. (1); Harms, A.V. (1); Sam, A. (1); Levy, I. (1); Pham, M.K., Blinova, O. (1); Mc Ginnity, P. (1);Fujak, M. (1); Bartocci, J. (1); Rozmaric, M., Morris, P. (1); Liong, L. (1); Osborn D. (1). (1) International Atomic Energy Agency, Environment Laboratories. Since 1994 the IAEA collaborates with the Japanese laboratories involved in marine radioactivity monitoring to help ensure high data quality and comparability of results. Annual joint sampling is organised offshore the Fukushima Daiichi Nuclear Power Plant, for the collection of seawater, sediment and fish for interlaboratory comparisons of radionuclides in environmental samples. In addition annual PTs are organised for radionuclides in well characterised seawater samples. The paper synthesizes the results and conclusions of this work for the period 2014-2017, including seven sampling missions and four proficiency tests. Log 422. DETECTION AND SEPARATION OF RADIUM-226 FROM HIGHLY SALINE ENVIRONMENTAL SAMPLES. Pier, R. (1); Nilsson, M. (1). (1) University of California, Irvine. TThe unconventional production of natural gas from shale resources has increased the total dry natural gas production in the United States by 35% from 2005 to 2013 (U.S. Energy Information Administration, 2013). The increasing demand from various power markets will likely cause increase in U.S. natural gas consumption, leading to an increase in the volume of waste. However, there have been concerns regarding the effective management of the high salinity wastewaters that return to the surface, mainly due to the mobility and local accumulation of naturally occurring radioactive materials (NORMs), such as radium-226. Current treatment strategies include temporary storage sites and treatment using wastewater plants; however, the high salinity of these wastewaters has created a challenge for wastewater treatment facilities, especially its impact on water quality near discharge sites. Therefore, other treatment technologies may be required to prevent contamination of surface and groundwater and to minimize radiation doses to workers and the public. This presentation will discuss results from analytical methods used to assay radium-226 and separation studies using ion exchange resins. Studies include source preparation and analysis via alpha spectrometry to assay low-level Ra-226. Sorption and desorption kinetic studies will provide insight on the performance of two cation exchange resins: Dowex 50W-X8 resin and a newly developed resin from ResinTech, RSM-25HP. Simulated and actual flowback water will be used to analyze the separation of Ra-226 from highly saline samples using the aforementioned resins. Log 424. STATUS AND PLANS FOR THE NETWORK OF ANALYTICAL LABORATORIES FOR THE MEASUREMENT OF ENVIRONMENTAL RADIOACTIVITY (ALMERA). Osvath, I. (1); Pitois, A. (1); Tarjan, S. (1); Groening, M. (1); Osborn D. (1). (1) International Atomic Energy Agency, Environment Laboratories. With 164 laboratories in 78 countries, IAEA's ALMERA network is the largest international network of analytical laboratories with expertise in the measurement and monitoring of environmental radioactivity. The aim of the network is to support analytical excellence through custom-designed annual proficiency tests and interlaboratory comparisons, method development and validation, training and workshops. Member laboratories participate in the characterisation of reference materials for natural and anthropogenic radionuclides in environmental matrices led by the Agency. Particular attention is given to developing the network's capacity to report timely and accurate measurement results in the case of radiological or nuclear emergencies. In 2017 a rapid sample measurement and reporting exercise was organised during an IAEA international emergency response exercise, with very good results. Multi-annual analyses of proficiency test results and especially designed interlaboratory comparison exercises allow the identification of analytical problems encountered by the member laboratories, which are then addressed through method development and training. ALMERA represents an important pool of expertise and is actively supporting capacity building in analytical laboratories in developing countries. This paper presents results and planned development of the ALMERA network.


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Log 426. INVESTIGATION OF URANIUM DIOXIDE FUEL PELLETS FOR NUCLEAR FORENSIC APPLICATIONS. Spano, T.L. (1); Corcoran, L. (1); Simonetti, A. (1); Dorais, C. (1); Lewis, S.R. (1); Gunther, T. (1); Burns, P.C. (1, 2). (1) Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame. (2) Department of Chemistry and Biochemistry, University of Notre Dame. A comparative investigation of the trace element compositions and structural properties for two uranium dioxide fuel pellets was conducted for nuclear forensic applications. One of the fuel pellets probed in this study consists of natural U (0.71 wt% 235U) and the other contains enriched (3.98 wt% 235U) UO2. Trace element abundances were determined utilizing solution mode inductively coupled plasma mass spectrometry (SM-ICP-MS). Cr, Mo, W, Co, and Ni impurities were observed in both fuel pellets, which likely originate from fabrication processes. Additionally, Zr was detected in the fuel pellet of natural U isotopic abundance. Structural properties of the UO2 fuel pellets were examined using powder X-ray diffraction (pXRD) and Raman spectroscopy. Peak splitting, likely resulting from reduction of cubic symmetry in the UO2 structure, was detected in the pXRD patterns for the fuel pellets. Peak broadening of the T2g U-O stretching vibrational mode was observed in the Raman spectra of both fuel pellets and the magnitude of broadening may correspond to differential aging of the two materials. In addition, X-ray fluorescence spectroscopy was used to characterize the homogeneity of the fuel pellets, and non-traditional isotope signatures (e.g., B, Ca, Fe) were explored for the purpose of establishing novel nuclear forensic methodologies. Log 428. CHRONOLOGIES OF UNUSUAL RADIONUCLIDE RELEASES IN EUROPE IN 2017: THE EPISODES OF I-131 IN SPRING AND Ru-106 IN FALL. Steinhauser, G.(1); Masson, O. (2). (1) Leibniz University Hannover. (2) IRSN. In response to the Chernobyl nuclear accident, several European radionuclide stations established the Ring of Five (Ro5) as an informal network to pin down unusual detections in any of their stations. The Ro5 has grown to one of the largest and most capable informal network radionuclide monitoring stations worldwide. Detections of anthropogenic radionuclides in isolated stations of the Ro5 are not uncommon, however, two events in 2017 stood out in the history of the network. First, in January and February, an unusually long episode of I-131 in European air was monitored. The main source appeared to be in Eastern Europe; however, unusual weather conditions prevented the dilution and suggest that in fact multiple smaller sources contributed to the unusual detections. In fall 2017, an unusual episode of Ru-106 was detected in Europe and globally. Presently, the source of this release is subject to intense speculations. We will present the latest results on both events. Log 429. IMAGING OF SPECIAL NUCLEAR MATERIALS USING MONOENERGETIC GAMMA RAYS FROM LOW-ENERGY NUCLEAR REACTIONS. Rose, P.B. (1); Harms, J. (1); Erickson, A.S. (1). (1) Georgia Institute of Technology. Cargo containers are transported into the country at a staggering and increasing rate, resulting in an expanded vulnerability to nuclear terrorism via smuggling devices hidden inside. Alarmingly few of these containers are inspected for nuclear threats and the current methods of scanning do not provide information on the material, but merely the shape via imaging with high energy x-rays from bremsstrahlung sources. The pursuit of shielded special nuclear material in cargo can be facilitated by active interrogation employing discrete energy photons. If the gamma ray energies are sufficiently well separated, as the case in 11B(d,n-.)12C reaction resulting in photons of numerous energies up to 15.1 MeV, spectral analysis is possible with a variety of detector technologies. We have designed a proof on concept system to interrogate cargo containers using discrete energy gamma rays produced from low energy nuclear reactions generated by a compact ion accelerator. These multiple, monoenergetic gamma rays can be used to create the same images as the bremsstrahlung methods, but also provide a means to estimate the Zeff of the material in each pixel of the image via differential attenuation techniques. Cherenkov detectors offer a low-cost solution but require a special approach to design and energy calibration due to the lack of resolution in order for spectral analysis to take place. High-density scintillators or semiconductor detectors can yield much better spectral information, but are considerably more expensive. Intermixing detector technologies in a compact array using silicon photomultipliers can lead to fine spatial resolution images of areal density and approximate Zeff.


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Log 430. UNDERSTANDING AND QUANTIFYING THE SYSTEMATIC EFFECTS OF CLUTTER WITHIN A RADIATION DETECTION SCENE. Stewart, I.R. (1); Nicholson, A. D. (1); Archer, D.E. (1); Willis, M.J. (1); Swinney, M.W. (1); Garishvili, I. (1); Ray, R.R. (1). (1) Oak Ridge National Laboratory, In an age of growing security threats, the risk that an adversary will obtain the materials required to manufacture a nuclear weapon or dispersion device remains at the forefront of the national security missions and presents unique challenges to deter and detect such a scenario from occurring. Detecting such actions through the implementation of radiation detectors only increases in difficulty in a variable or dynamic background environment where various objects, or clutter, enter and exit the scene, such as in crowded urban areas or high-traffic intersections. A cluttered detection scene introduces a variation in signals due to the attenuation of naturally occurring radioactive material distributed within the scene or by introducing new, non-threatening radioactive materials, such as medical isotopes. Efforts are currently underway at Oak Ridge National Laboratory (ORNL) to understand the effects that clutter introduces to a scene in order to quantify the expected signal variation inherent to a dynamic scenario. A water-proof enclosure containing a 2x4x16 NaI(Tl) detector, a 3x3 NaI(Tl) detector, and a He-3 detector has been placed in the ORNL reservation to observe the daily operations and subsequent changes in signals detected from a time-varying, dynamic environment. In addition to radiation sensors, contextual sensors such as LiDAR and camera systems are utilized to identify the presence and magnitude of clutter in real time with data fusion techniques. With several months of data collected from the sensors, a better understanding of the background source distribution within the scene and the systematic effects clutter introduces is analyzed. Log 431. REACTOR MODELING UNCERTAINTIES FOR ANTINEUTRINO DETECTION AT HFIR USING THE PROSPECT EXPERIMENT. Conant, A.J. (1); Bowden, N.S. (2); Erickson, A.S. (1). (1) Georgia Institute of Technology. (2) Lawrence Livermore National Laboratory. Antineutrino detection experiments have demonstrated the ability to non-intrusively monitor the operational status of nuclear reactors. This could provide a new safeguards tool for verifying a State's declarations of fissile material accountancy. The next generation of short-baseline neutrino oscillation experiments will demonstrate such detection capabilities close to research reactor cores with little cosmic ray attenuating burden. For example, the Precision Reactor Oscillation and Spectrum (PROSPECT) experiment will operate within ten meters of the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) using a four-ton liquid scintillator detector. This paper describes the status of the PROSPECT experiment, set to begin data collection in early 2018, as well as reactor modeling efforts to verify reactor power and uncertainty in antineutrino production. High-fideling modeling in MCNP and SERPENT was used to quantify reaction rates and compare HFIR to other reactors. The impact of antineutrinos from structural material activation and spent fuel decays will be discussed in detail.


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Log 432. PRECISE MEASUREMENTS OF U-233 GAMMA EMISSIONS USING MAGNETIC MICROCALORIMETERS WITH ULTRA-HIGH ENERGY RESOLUTION. Kim, G.B. (1); Kempf, S. (2); Hummatov, R. (3); Flynn, C. (1); Boyd, S.T.P. (3); Enss, C. (2); Friedrich, S. (1). (1) Lawrence Livermore National Laboratory. (2) Heidelberg University. (3) University of New Mexico. We have used magnetic microcalorimeter (MMC) gamma detectors to measure the low-energy gamma emissions of U-233 with an accuracy of a few eV. U-233 is currently of interest in nuclear safeguards, because it is a fissile isotope that is produced by neutron irradiation of thorium-232 in the thorium fuel cycle. However, some of the nuclear data of U-233 in the literature have relatively high uncertainties, especially at lower energies where lines can overlap or be dominated by a high Compton background. Magnetic microcalorimeters (MMCs) operated at a temperature of 10 mK have an energy resolution below 50 eV, and can resolve lines with similar energy. To address the difficulty of low-temperature operation and small detector size, we have adapted a cryostat that can attain 10 mK under computer control and without the use of cryogenic liquids. We present recent MMC measurements of U-233 and discuss the contributions of statistical and systematic errors. We have repeated the experiments with different MMC gamma detectors and different amplifier chains to increase the confidence in some observed deviations from literature values. These measurements of lines with similar energy are an illustrative example of the improved accuracy that MMCs can provide for nuclear data and non-destructive assay. Log 434. NOBLE GAS MIGRATION AT THE U20AZ TESTBED. Johnson, C. (1); Aalseth, C.E. (1); Alexander, T.R. (1); Bowyer, T.W. (1); Chipman, V. (2); Cooper, M.W. (1); Day, A.R. (1); Drellack, S. (2); Foxe, M.P. (1); Fritz, B.G. (1); Hayes, J.C. (1); Humble, P. (1); Keillor, M.E. (1); Kirkham, R.R. (1); Krogstad, E.J. (1); Lowrey, J.D. (1); Mace, E.K. (1); Mayer, M.F. (1); McIntyre, J.I. (1); Milbrath, B.D. (1); Misner, A. (1); Morley, S.M. (1); Panisko, M.E. (1); Okagawa, R.K. (2); Olsen, K.B. (1); Ripplinger, M.D. (1); Seifert, A. (1); Suarez, R. (1); Thomle, J. (1); Townsend, M.J. (2). (1) Pacific Northwest National Laboratory. (2) Nevada Security Technologies, LLC (NSTec). An underground migration study was performed at the location of an underground nuclear explosion on the Nevada National Security Site. As part of this study, two radioactive noble gases and two stable tracer gases were injected into the nuclear explosion test cavity and allowed to migrate naturally. Soil gas samples were then collected from a series of boreholes over a period of 10 months around the cavity and at a range of depths from the shallow subsurface (3 meters) to deeper levels (~160 meters). These samples were analyzed for each of the injected tracers as well as two additional tracers that were already present at the site, and the concentration in the sample and dilution from injection calculated. These results have provided insight into the subsurface plume development and evolution and the relative migration rates of the radioactive noble gases and injected tracers. The results were also compared to the results of the previous noble gas migration experiment performed at the same site in 2013 and the possible reasons for differences between the results examined.


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Log 435. ESTIMATION OF ANTHROPOGENIC ORGANO-CHLORINE, BROMINE AND IODINE COMPOUNDS IN APOLAR LIPID FRACTIONS OF BOVINE MILK BY SOLID-PHASE EXTRACTION AND NEUTRON ACTIVATION ANALYSIS. Isaac-Olive, K. (1, 2); Kyaw, T.T. (1, 3); Chatt, A. (1). (1) Trace Analysis Research Centre, Department of Chemistry, Dalhousie University, Canada. (2) Medical Physics Graduate Program, School of Medicine, Universidad Autónoma del Estado de México (UAEMex), Mexico. (3) Thanlyin Technological University, Myanmar. . The consumption of bovine milk in Canada is about 70 L per capita per year. Milk is known to contain several extractable organohalogen (EOX) compounds which are associated with lipids. In our laboratory in the past, the halogen concentrations in the lipid extracts of bovine milk were measured. This extract included both naturally occurring and anthropogenic organohalogen compounds. Highly toxic anthropogenic organohalogens are reported to be associated with the most apolar fraction of the lipid extracts. In this work, the bovine milk lipid extracts were first fractionated to apolar, less polar and polar portions by a solid-phase extraction (SPE) method using a LC-Si column. The apolar fraction was further separated into 4 more fractions (from apolar to most polar) by another SPE method using a Florisil column. The samples were irradiated at the Dalhousie University SLOWPOKE-2 reactor in a thermal neutron flux of 2.5x1011 cm-2 s-1 for 10 min, decayed for 2 min, and counted for 10 min for the determination of chlorine, bromine and iodine. Although these three halogens were detected in all separated fractions, much of them were found in the most apolar fraction which contained hydrocarbons. This is a strong indication of the presence of anthropogenic EOX compounds in milk. Log 437. SOFT X-RAY SYNCHROTRON RADIATION SPECTROMICROSCOPY STUDIES OF RADIOACTIVE AND ACTINIDE MATERIALS. Shuh, D. K. (1); Altman, A. (1); Minasian, S. G. (1); Pacold, J. I. (1); Smiles, D. E. (1); Tyliszczak, T. (1); He, L. (2); Harp, J. (2); Meyer, M. (2); Suzuki, E. (3); Suzuki, S. (3); Yaita, T. (3); Yoshida, H. (3); Davisson, L. (4); Donald, S. (4); Knight, K. (4); Kristo, M. (4). (1) Lawrence Berkeley National Laboratory. (2) Idaho National Laboratory. (3) Japan Atomic Energy Agency, Japan. (4) Lawrence Livermore National Laboratory. Soft X-ray synchrotron radiation methodologies are being developed and employed at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory (LBNL) to elucidate the electronic structure of radioactive and actinide materials. Results from these investigations have begun to provide improved fundamental knowledge that can be used as a scientific basis for the enhanced design of actinide materials, complexes, ligands, and the overall understanding of actinide materials. The experimental developments at the ALS have centered on studies of radioactive materials with the Molecular Environmental Science (MES) soft X-ray scanning transmission X-ray microscope (STXM) at Beamline 11.0.2 for spatially-resolved near-edge X-ray absorption spectroscopy (XAS). The spectromicroscopy capabilities of the STXM provide the means to determine the speciation and composition in a range of actinide materials, particularly those of technological and environmental interest with spatial resolution that can reach to the true nanoscale. A particular emphasis has been on the use of light atom (B, C, N, O, F, Na, Mg, Al, Si) ligand K-edge XAS technique to determine the electronic structure characteristics in an array of unique and relevant materials. Furthermore, there are a host of additional electron energy level thresholds (such as the L-edges of the transition metals, the M-edges of the lanthanides, and others) that can be probed by near-edge XAS in the soft X-rays. Recently, STXM spectromicroscopy studies have been extended to fast ion beam (FIB) prepared radioactive and irradiated material specimens in collaboration with Idaho National Laboratory.


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Log 438. THE DEPENDENCE OF FISSION MASS YIELDS ON THE NUCLEAR STRUCTURE OF THE COMPOUND NUCLEUS. Koehl, M.A. (1), Rundberg, R.S. (2), Shafer, J.C. (1). (1) Colorado School of Mines. (2) Los Alamos National Laboratory. Relative fission product yields have been determined for three sampling positions in the USGS TRIGA Mark I reactor through radiochemical analysis. The relative mass yield distribution for valley nuclides decreases with epithermal neutrons compared to thermal neutrons. The mass yield of valley nuclides had been found to belong to two groups for neutron resonances of the fission cross section of U-235. ENDF-BVII.1 was used to identify the J-value associated with these groups. The J=3- resonances were expected to yield a more symmetric mass yield distribution because the 3- level is lower energy than the 4- level in the compound nucleus, 236U, and would present a lower barrier to fission. The opposite was found when fitting the thermal and epithermal yields. The thermal and epithermal yields could only be reproduced by assuming the J=4- as the more symmetric mass yield distribution. This is attributed to the 3- level belonging to an octupole deformation and the 4- level being the ground state of a two quasi-particle quadrupole band. The octupole deformation is inherently assymetric. The relative yields of 111Ag and 115gCd to 99Mo were measured by chemically separating the elements and beta counting those samples. The ratios in samples of irradiated uranium were determined for both a thermal and epithermal flux in this study. These values agree well with a previous study that used activation foils to determine the flux. Log 439. DEVELOPMENT OF AN AUTOMATED ANION EXCHANGE SEPARATION SYSTEM FOR HIGH THROUGHPUT ULTRA-SENSITIVE ICP-MS DETERMINATION OF Th-232 AND U-238. di Vacri, M.L. (1); Arnquist, I.J. (1); Hoppe, E.W. (1). (1) Pacific Northwest National Laboratory. Experiments studying rare events, such as those searching for the direct evidence of dark matter and neutrino-less double beta decay, are among the most exciting challenges in modern physics. One of the main concerns for these experiments is the radio-purity of the materials used for the construction of the experimental apparatus. In particular, the content of radionuclides such as Th-232 and U-238 and their daughter products in these materials has to be sufficiently low not to elevate detector background levels. Purity levels are very demanding, tolerated contamination levels are typically of the order of pg/g or lower. Assiduous and clean sample preparation is necessary to attain ultrasensitive (<1 pg/g) detection limits. Separation of the matrix and/or pre-concentration of the analyte are often necessary when quantifying ultra-trace concentrations. In this work, an automated system developed for matrix separation and analyte pre-concentration prior to ICP-MS ultra-trace detection is presented; samples where the system was employed include copper and polymers. The system works in conditions of extreme cleanliness and reproducibility, allowing robust and reliable ultra-trace assay of thorium and uranium with high throughput. The system has been developed for ultra-low background physics applications but it can potentially be applied in all fields where a fast and reproducible assay of materials for long-lived radionuclides is required, such as environmental monitoring or electronics and semiconductor industry.


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Log 440. MAKING AMERICIUM HEXAVALENT AGAIN: A COMPARISON OF AMERICIUM OXIDATION AND SEPARATION APPROACHES. Shafer, J.C. (1); McCann, K.C. (1); Lapka, J.L. (2); Nash, K.L. (2); Mincher, B.J. (3); Sinkov, S.I. (4); Lumetta, G.J. (4). (1) Colorado School of Mines. (2) Washington State University. (3) Idaho National Laboratory. (4) Pacific Northwest National Laboratory. The oxidation and selective recovery of hexavalent americium using solvent extraction under highly acidic conditions has been demonstrated with two oxidants, sodium bismuthate and copper(III) periodate, and two extractants, diamyl amyl phosphosphonate (DAAP) and monoamides, respectively. These extractant and oxidant combinations have different limitations and benefits. The insolubility of sodium bismuthate provides a potential engineering challenge for the separations equipment used in engineered solvent extraction studies, but the rapid reduction of copper periodate in >3M acidic media limits its utility for americium oxidation to lower acidities. Although DAAP is a more basic extractant than monoamides considered in this study, studies suggest monoamide extractants are less reducing than DAAP and might provide more consistent extraction results. Based on the combined benefits and limitations of these approaches, either monoamide extractants should be used with sodium bismuthate or copper periodate should be used with a cation exchange reagent, such as HDEHP, under lower acid conditions. Means of potentially improving the properties of sodium bismuthate or Cu(III) oxidants are discussed. Log 441. DECIPHERING THE ORIGIN OF COMPOSITIONAL HETEROGENEITY IN TRINITITE FALLOUT. Fitzgerald, M.A. (1); Knight, K.B. (2); Matzel, J.E. (2); Zurong, D. (2); Czerwinski, K.R. (1). (1) University of Nevada Las Vegas. (2). Lawrence Livermore National Laboratory. Trinitite is a compositionally heterogeneous glassy material resulting from the Trinity nuclear explosion, and reflecting a rapidly cooled mixture of device material, structural material, and proximate environmental precursor materials such as soil and rock. To understand the formation mechanism that produces such glasses, we apply multivariate curve resolution – alternating least squares (MCR-ALS) to 3249 analyses on 13 fallout samples. This approach estimates precursor compositions, which provides an objective means for interpreting individual sample formation history on the basis of morphology and compositional heterogeneity. Our results show that environmental materials known to be present at ground zero, such as alkali feldspar, calcite, and quartz, are volumetrically significant in fallout. Additionally, we infer the presence of previously unreported Al-Si rich composition reflecting volatile loss. Ancillary to these environmental compositions, we resolve an Ca-Fe-Mg rich composition, which we interpret as an anthropogenic vapor contribution concentrated along interfaces of subsumed or attached (agglomerated) objects. We explore the physical and chemical processes controlling radioactivity incorporation during fallout formation by combining spatial-chemical relationships with image plate autoradiography. Based on the correlation of activity with the Al-Si and Ca-Mg-Fe precursors, we propose a three-stage model for aerodynamic fallout formation: (1) a condensation event, wherein molten soil components serve as heterogeneous nucleation sites for vapor from the near-field environment and remnant fuel, (2) agglomeration of this material onto the surface of larger molten droplets or host objects from the soil, and (3) subsequent mixing of the condensate through the interior of the host object.


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Log 442. UNDERSTANDING MOLECULAR AGGREGATION TO DEVELOP PREDICTIVE NUCLEAR FORENICS OF PUREX TRACE METAL SIGNATURES. Baldwin, A.G.(1); Bridges, N.J.(2); Shafer, J.C.(1). (1) Colorado School of Mines. (2) Savannah River National Laboratory. The Department of Homeland Security (DHS) is interested in understanding how relevant stages of the nuclear fuel cycle create, persist, or modify discriminating material characteristics in the metal or oxide forms of uranium or plutonium. To support these evaluations, analytical capability is being developed to assess the partitioning behavior of trace elements in the Plutonium URanium EXtraction (PUREX) process under a variety of conditions. While certain parameters regarding trace metals in the PUREX process are known very well - including their decontamination factors or partitioning of singular trace metals into tri-butyl phosphate (TBP) - the distribution coefficients of these metals in the presence of more realistic PUREX conditions are less well characterized. The presented work uses radiotracers produced using the 1 MW USGS TRIGA Reactor to assess the partitioning of Sm-159, Mo-99, Ce-143, Cr-51, La-141, Ru-103, Sr-85, Cs-134, Zr-95, Rb-86, and Fe-59. These radiotracers are used in cooperation with cold, carrier metal nitrates to generate metal concentrations anticipated during PUREX processing. Early results indicate partitioning of trace metals can be assessed and this partitioning is generally consistent with anticipated patterns, but some data is not readily explainable using the classical coordination chemistry model to describe metal recovery using TBP. Alternative models, such as reverse micelle formation, are considered and probed using molecular dynamics and diffusion NMR techniques. The compiled data suggests accounting for the TBP aggregation will be necessary to develop models capable of predicting trace metal partitioning patterns. Log 443. MEASUREMENT METHODOLOGY DEVELOPMENT FOR AN ULTRA-LOW-LEVEL LIQUID SCINTILLATION COUNTER. Finch, Z.S. (1); Orrell, J.L. (1); Pierson, B.D. (1); Gartman, B.N. (1); Arnquist, I.J. (1); Seiner, B.N. (1). (1) Pacific Northwest National Laboratory. PNNL has developed an ultra-low-level liquid scintillation counter located in our shallow underground facility intended to support national security and nonproliferation missions. This alpha and beta detection system facilitates lower detection limits than currently achievable with commercial instruments and/or can reduce the sample size required for quantification. Initial studies established preliminary background rates and energy range sensitivity. This work expands on previously published data and initiates development of measurement methodologies by counting NIST traceable standards with a diverse range of decay properties likely to be encountered in environmental samples. Isotopes considered include Fe-55, Cs-134, Cs-137, Pm-147, Eu-152, and Am-241. Efficiencies reported are calculated by comparing certified values to measured rates above background and energy threshold. Previous work has suggested commercial scintillation cocktail mixtures are potentially the largest contributing background source remaining. An independent assay analysis via inductively coupled plasma mass spectroscopy (ICP-MS) of the scintillation cocktail and the poly-vial used for counting was carried out in an effort to understand if yet lower background levels are potentially achievable in the underground liquid scintillation counter system through the purification or production of a custom cocktail targeted at ultra-low-level analysis. Log 444. STATE OF PRACTICE AND EMERGING APPLICATION OF ANALYTICAL TECHNIQUES FOR NUCLEAR FORENSIC ANALYSIS: HIGHLIGHTS FROM THE 5TH COLLABORATIVE MATERIALS EXERCISE OF THE NUCLEAR FORENSICS INTERNATIONAL TECHNICAL WORKING GROUP (ITWG). Schwantes, J.M. (1); Taylor, F. (2); Marsden, O.(2). (1) Pacific Northwest National Laboratory, US Department of Energy. (2) AWE, UK. The Nuclear Forensics International Technical Working Group recently completed its Fifth, and largest, Collaborative Materials Exercise, with participating laboratories from 20 countries or international organizations. Exercise samples (including two samples of low enriched uranium oxide) were shipped as part of an illicit trafficking scenario, for which each laboratory was asked to conduct nuclear forensic analyses in support of a fictitious criminal investigation. The outcomes from this exercise were used to objectively review the state of practice of nuclear forensic analysis and identify emerging applications of analytical techniques being applied by the community. Additionally, we report on a number of trends in nuclear forensic analyses over the past two decades of Collaborative Materials Exercises.


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Log 445. STUDY OF THE PHASE STRUCTURE AND STABILITY OF U-NB ALLOY BY X-RAY DIFFRACTION. Wang, X. (1); Zhang, Y. (2). (1) China Academy of Engineering Physics, China. (2) Science and Technology on Surface Physics and Chemistry Laboratory, China The phase structure and stability of U-Nb alloy have been studied using ex-situ and in-situ X-ray diffraction in our work. The experimental results show that the content of Nb and quenching rate are the most important factors to the structure of U-Nb alloy, especially to the metastable rich-U alloy samples. The stability of monoclinic martensitic phase is investigated specially because of its unique structure and properties. The results indicate that phase transformation may be occurred in U-Nb alloy during aging at 200 °C, and the its microstructure changes evidently with temperatures and time. For example, the interplanar spacing of (110) and (021) reduce surprisingly with temperature increasing until 240.C, and recover to the origin values at higher temperature. The maximum constriction of (110) and (021) exceed the range of elastic deformation. These suggest that the effect of lattice distortion on microstructure may be the real reason for the low-temperature aging mechanisms of monoclinic U-Nb alloy. The experimental results can assist in understanding phase structure and stability of U-Nb alloy, especially the strengthening mechanism of monoclinic phase during low-temperature aging. Log 446. A METHOD TO QUANTIFY THE Ar-37 EMANATION FRACTION IN POWDERS AND ROCKS. Johnson, C. (1); Prinke, A. (1); Lowrey, J. (1); Humble, P. (1); Mace, E. (1); Alexander, T. (1); Williams, R. (1). (1) Pacific Northwest National Laboratory. Activation products, such as Ar-37, comprise an important component of the radionuclide signature from an underground nuclear explosion (UNE). While activation products from a UNE can be predicted based on knowledge of the relevant cross-sections and geologic composition, uncertainty still remains as to what fraction of the generated activation products make it out of the geologic matrix and into air-filled pore space - the emanation fraction. A system was developed to quantify the emanation fraction from samples ranging in size from powder to small (multiple centimeter) rocks. Samples were selected by comparing their expected calcium content (Ar-37 production) to their potassium (Ar-39 production) and uranium (other contaminants) content. The chosen rock types were then crushed and sieved to various grades before being encapsulated in quartz ampoules. The samples were then irradiated at the Device Assembly Facility at the Nevada National Security Site. Once the samples were returned to PNNL, the gas was extracted from the samples on a custom apparatus and cryogenically trapped. The extracted gas was then processed to separate the argon and load it into a proportional counter for counting. The measured activities were then compared to the calculated activities in each sample and the emanation fraction for that sample was determined. Log 447. ACTINIDE SEPARATIONS WITH TEHA AND TEHP USING SOLVENT EXTRACTION AND EXTRACTION CHROMATOGRAPHY. Rolfes, J.R. (1); Henderson, R.A. (2); Bertoia, J. (1); Sudowe, R. (3). (1) UNLV. (2) LLNL. (3) Colorado State University. In previous studies, tris(2-ethylhexyl)amine (TEHA) and tris(2-ethylhexyl)phosphate (TEHP) have been shown to extract zirconium and hafnium using solvent extraction and extraction chromatography. Studies with the other elements with similar chemistries can be performed using liquid-liquid extraction as well as extraction chromatography. When properly manipulated, these investigations can then be used as a separation scheme for the actinides. The results of a detailed study investigating the solvent extraction of Th, U, Np, Pu, Am, and Cm from HCl by TEHA and TEHP will be presented together with the use of extraction chromatography to separate these elements.


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Log 448. MEDICAL ACTIVATED CHARCOAL TABLETS AS A CHEAP TOOL FOR PASSIVE MONITORING OF GASEOUS 131-I ACTIVITY IN AIR OF NUCLEAR MEDICINE DEPARTMENTS. Mroz, T. (1); Brudecki, K. (2); Mietelski, J.W. (2); Cicho., J. (3); Bartyzel, M. (2); Korna., A. (1). (1) Pedagogical University of Cracow. (2) Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences. (3) University of Silesia in Katowice. It is well known, that monitoring of radioactivity released from nuclear medicine departments is very important for ensure radiation safety for patients and personnel. Unfortunately, equipment for air sampling is often expensive, loud and is not suitable to use in hospitals. As our previous studies showed, gaseous fraction of 131-I is main component of total 131-I activity in air, our goal was to find cheap and simple system for passive monitoring of gaseous 131I activity concentration in air of all nuclear medicine departments. We decided to use medical activated charcoal tablets, because charcoal is excellent material for 131-I trapping and tablets are anywhere easily accessible. Our proposed sampling protocol contains tablets preparation, exposure and measurements using HPGe detector. Different methods of tablets preparation (drying, impregnation with KI or NaOH) were tested and also experimental chamber was prepared for estimating gaseous 131I trapping efficiency on tablets in different conditions. Finally, tablets were placed in plastic holders and tested in nuclear medicine department "hot room" (where Na131-I tablets are being prepared for patients), corridor and patient's room. Log 450. LONG TERM MONITORING OF RADIOCESIUM DEPOSITION NEAR THE FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT: EFFECT OF INTERCEPTION OF RADIOCESIUM ON GRASSES. Hirose, K. (1). (1) Sophia University, Japan. Monthly deposition of Cs-137 at the site near the Fukushima Daiichi Nuclear power plant (FDNPP) has been monitored continuously since March 2011. Although the monthly Cs-137 deposition decreased with time, the higher monthly Cs-137 deposition, exceeded 1 kBq m-2, was observed in winter 2017. In case when higher radioactive deposition continues, interception is an important pathway to radioactive contamination of vegetables. However, there were a few studies conducted after the FDNPP accident. Just after the FDNPP accident, radionuclide concentrations in grasses collected in the area about 30km from the FDNPP have been measured according to the emergency radioactivity monitoring plan. There was a correlation between monthly Cs-137 deposition and monthly mean Cs-137 concentration in grasses in 2011. We, therefore, calculated a conventional interception factor (0.5 m2 kg,wet-1) from observed values of the Cs-137 concentrations in grass and monthly Cs-137 deposition observed in 2011. The conventional interception factor allows us to estimate monthly mean concentrations of radiocesium (Cs-134 + Cs-137) in grasses (vegetables) from the monthly deposition of radiocesium. The results suggest that there is possibility that the concentrations of radiocesium in vegetables collected near the FDNPP in 2017 exceed a restriction value of 100 Bq kg, wet-1. Log 452. CARBON-14 CHEMICAL PARTITIONING IN SOILS, AIR, AND BIOTA IN THE VICINITY OF NUCLEAR SITES. Ward, J. L. (1); Snow, S.S. (1); Olson, J.E. (1). (1) Idaho National Laboratory. Nuclear reactors and nuclear weapons testing have introduced significant quantities of carbon-14 (14C) into the environment; when oxidized to form CO2, 14C is readily uptaken by plants and can increase the dose to biota in the near field of nuclear source terms. Evaluation of the partitioning of 14C into different chemical forms of carbon in air, soil, and biota can provide insights into the effects of nuclear releases to the environment as well as environmental carbon cycling processes. In this work, analyses of 14C from air, soil and biota samples taken from the vicinity of several nuclear sites (including the Idaho National Laboratory and the Nevada National Security Site) are presented. Analyses of tree rings taken from trees in close proximity to a nuclear reactor and above ground nuclear weapons testing area are utilized to estimate annual gaseous 14C plumes from major nuclear source terms. For soil samples containing elevated 14C, a closed vessel acid leach-combustion protocol is presented that enables separation and quantification of 14C associated with inorganic, organic, and elemental carbon forms. The implications these data have upon radiocarbon transport, remediation, and global carbon cycling processes will be discussed.


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Log 453. STANDOFF ISOTOPE SENSITIVE FLUORESCENCE SPECTROSCOPY OF LASER ABLATION PLUMES. Hartig, K.C. (1, 2); Phillips, M.C. (2); Brumfield, B.E. (2); Harilal, S.S. (2). (1) Nuclear Engineering Program, University of Florida. (2) Pacific Northwest National Laboratory. When a high-power pulsed laser is focused onto a sample surface an extremely dynamic and luminous micro-plasma will be formed through laser ablation (LA). LA is a powerful technique that has been implemented into a number of material processing and analytical applications. In this work, we report on the standoff isotopic analysis of a metal target using laser-induced fluorescence (LIF) of LA plumes. The LA plumes were produced on the surface of a Gd metal target, which has a number of naturally occurring isotopes, following irradiation by the fundamental emission of a high-power nanosecond Nd:YAG laser. A collinear LIF pumping scheme was used to resonantly excite neutral Gd atoms present in the LA plume. The resulting optical emission, due to thermal and non-resonant LIF excitation, was monitored using two-dimensional fluorescence spectroscopy. The ultra-narrow linewidth of the tunable LIF pumping laser allowed for the selective excitation of individual Gd isotopes in the LA plume. It is well known that the presence of reactive species (i.e. oxygen) in the ambient environment complicates in-field and standoff analysis techniques, and when LA is performed in the presence of oxygen plasma assisted combustion/oxidation occurs, which drastically reduces the magnitude of the measured LIF emission. While the strongest LIF emission was observed under an inert atmosphere, we show that isotopic sensitivity is achievable using the LIF technique under ambient conditions in a standoff configuration. Current work on the expansion of the standoff LIF technique to uranium isotopic analysis will also be discussed. Log 454. COMPARATIVE EVALUATION OF NEUTRON SPATIAL DISTRIBUTION BETWEEN FAST AND THERMAL EQUIVALENT FLUX. Kim, J. (1); Lee, H. (1). (1). Korea Atomic Energy Research Institute, Republic of Korea In principle, the results of determining the neutron spatial distribution and the calculations of the equivalent flux with the neutron spectrum are in compatibility. The distortions have practically occurred when performing the neutron real flux measurement of the accelerator-based neutron source at KIRAMS MC-50 cyclotron (Korea Institute of Radiological & Medical Science) by using the stack of the activation foil arrays. In this study, the real neutron spectra of three arrays of activation foils made from Au, Ag, and Cu were investigated to deduce the reasons of the discrepancies with the equivalent flux. Log 455. ATONA- A LOW NOISE HIGH DYNAMIC RANGE AMPLIFIER SYSTEM FOR FARADAY COLLECTORS. Palacz, Z. (1). (1) Isotopx Limited. Faraday collectors are typically used to measure ion signal >1x10-13 amps in TIMS and in other magnetic sector mass spectrometers. Below this intensity ion counting detectors are generally used. The use of higher ohmic resistors e.g 1e12 ohm and 1e13 ohm, reduce the noise level, but the dynamic range and speed of response (tau) are compromised. We have developed a new amplifier (ATONA) that does not use a resistor in the feedback circuit. Noise levels of 3 x 10-17 amp for a 10 second integration are obtained on a TIMS Faraday collector. Lower noise levels of 8 x 10-18 amp have been obtained in noble gas collectors. The maximum signal that can be measured is in excess of 1nA. Tau response is baseline is achieved in 100ms, which is considerably faster than a resistor. Reproducibility of 234U/238U in natural Uranium with 2000cps of 234U is 1% 1RSD. ATONA can also be used in conjunction with ion counters . There is significant promise in using these detectors for total evaporation measurements, taking advantage of he large dynamic range and low noise.


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Log 456. LAWRENCE LIVERMORE NATIONAL LABORATORY NUCLEAR ACCIDENT DOSIMETRY AND ITS PERFORMANCE IN SIMULATED CRITICALITY ACCIDENTS. Hickman, D.P. (1); Jeffers, K.L. (1); Tai, L.I. (1); Stone, D.K. (1); Firpo, M.A. (1); Wong, C.T. (2); Lobaugh, M.L. (3); Heinrichs, D.P. (1). (1) Lawrence Livermore National Laboratory. (2) Radioanalytical Consulting and Education. (3) National Institute for Occupational Safety and Health. The Lawrence Livermore National Laboratory (LLNL) Nuclear Accident Dosimeter (NAD) is designed to measure multiple neutron energy regions, gamma dose, and provide quick sorting capabilities in the event of a nuclear criticality or high dose neutron event. Standard methods of neutron dosimetry are limited in the dose range they can provide, but the LLNL NAD can measure doses in excess of 10 Gy. This paper summarizes the LLNL NAD performance in studies and intercomparisons over the past several years (2009 through 2017) at the Silene (CEN-France), Caliban (CEN-France), Prospero (CEN-France), Godiva (NCERC -USA), and Flattop (NCERC -USA) reactors. The performance of the LLNL NAD has in all cases demonstrated good to excellent performance for neutron dose determinations. Improvements in the gamma dosimetry at the high doses generated at these facilities is needed and ongoing. The quick sort capabilities of the NAD have been extended so that personnel with significant doses can be identified at longer times post irradiations. The reactors in France are no longer in operation, but Godiva and Flattop are currently operated under the auspices of the Nuclear Criticality Experiments Research Center (NCERC) and have well characterized fluence and dose fields. New tests with the LLNL NADs are planned in May of 2018 using the Flattop reactor, and future tests and developments are being proposed. Log 457. EVALUATION OF CARBON TETRAFLUORIDE AS A RADIOXENON SURROGATE FOR UNDERGROUND GAS TRANSPORT. Paul, M.J. (1, 2); Byers, M.F. (1); Haas, D.A. (1); Biegalski, S.R. (1,3); De Luna, B.A. (1); Barth, B.S .(1). (1) The University of Texas at Austin. (2) Sandia National Laboratories. (3) Georgia Institute of Technology. Detection of radioactive gases, notably radioxenon, resulting from an underground nuclear explosive is a critical component of nuclear test monitoring. While laboratory and computational approximations of underground gas migration are well developed, field tests that follow tracer gases from an explosive cavity to the surface are required to benchmark the confidence of such models. Such in-situ experiments conducted in the past have utilized sulfur hexafluoride (SF6) as a benchmark or surrogate for radioxenon. Although a potent greenhouse gas, SF6 has been utilized given its history as a gaseous tracer in the atmospheric and earth sciences and similarity to xenon (Xe) in diffusive properties.This work evaluates the use of carbon tetrafluoride (CF4) as an alternative to SF6 for simulating Xe in underground transport experiments. Like SF6, CF4 is a fully fluorinated gas that is both inert and water insoluble while also found at low natural background levels. Laboratory experimentation, using a two-bulb gaseous diffusion apparatus and a Shimadzu GCMS-QP2010 SE, has shown that Xe is much more closely approximated by CF4 than SF6. Trials of Xe, CF4, and SF6 through 10-30 Ottawa sand estimate the effective diffusivity to be 0.0327, 0.0329, and 0.0254 cm2/s, respectively. Given the importance of diffusivity to mass transport in underground gas migration, CF4 can be considered an attractive surrogate for Xe when conducting field tests for underground nuclear explosion monitoring.


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Log 458. SUB-ATTOGRAM SENSITIVITY IN ACTINIDES ACCELERATOR MASS SPECTROMETRY. Child, D.P. (1); Hotchkis, M.A.C. (1); Froehlich, M. (2); Wallner, A. (2). (1) ANSTO, Australia. (2) ANU, Australia. In mass spectrometry, the sensitivity for a particular species depends on: (i) the ion source efficiency, (ii) the beam transmission and (iii) the background rate. With Accelerator Mass Spectrometry (AMS), in many cases the background may be close to zero, while the beam transmission is determined by choice of the charge state analysed after acceleration. The need for negative ions in AMS has a strong influence on the overall efficiency, since, for many species, negative ions are not formed as easily as positive ions. For AMS analysis of actinides, reasonable efficiency can only be achieved with molecular ions, usually using monoxide negative ions. The VEGA 1MV accelerator at ANSTO has been designed to provide optimum performance for actinides AMS, by enabling the analysis of actinides in the 3+ charge state at up to 1MV terminal voltage. The beam transmission for the 3+ charge state, using helium gas stripping, is greater than 40%. In recent tests, we have demonstrated ion source efficiency exceeding 3% for formation of PuO negative ions, and hence overall efficiency greater than 1%. For Pu-239, background rates limit sensitivity, due to interference from residual U-238. However, for Pu isotopes of mass 240 and above, sub-attogram sensitivity is achieved. This sensitivity is enabling new applications in nuclear astrophysics and source attribution in environmental studies. Log 459. THE USE OF BEEHIVES TO MONITOR U ISOTOPE SIGNATURES IN THE ENVIRONMENT. Yost, D.G. (1); Inglis, J.D. (1); Wende, A.M. (1); Schmidt, E.N. (1); LaMont, S.P. (1); Steiner R.E. (1). (1) Nuclear and Radiochemistry; Los Alamos National Laboratory. Materials from European honeybee (Apis mellifera) hives have historically been of interest for environmental monitoring. Due to the foraging behavior of honeybees, hive materials record biological and chemical signatures obtained from a localized area; such traces provide a geographical and temporal snapshot of environmental conditions. Previous studies have shown that hive materials accumulate a wide range of environmental indicators, including heavy metals and radionuclides. Presented here are the preliminary results of an effort at Los Alamos National Laboratory to determine the feasibility of using hives as a monitoring tool, primarily as an effort to determine isotope signatures. The study focuses on establishing if these actinides bioaccumulate in quantities that permit reliable isotope analyses from hive materials, specifically honey and pollen. Pollen extracts were separated from commercial honey samples, and both sample types were prepared for analysis using microwave digestion and ion exchange chemistry. U concentrations were determined by ICP-MS (inductively coupled plasma mass spectrometry). Analysis of the data revealed that each sample contained U, and that concentrations per gram of pollen extract were higher than that of the honey it was obtained from. This preliminary data suggests that pollen accumulates U and records its presence from the area in which it was collected, which indicates the potential to use hives as a monitoring system of radionuclides in the environment.


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Log 460. DETERMINATION OF Sr-89 AND Sr-90 ATOM CONCENTRATIONS OF A THERMAL NEUTRON IRRADIATED HIGHLY ENRICHED URANIUM TARGET BY ISOTOPE-DILUTION THERMAL IONIZATION MASS SPECTROMETRY. Springer, K.W.E. (1); Smith, S.C. (1); Friese, J.I. (1). (1) Pacific Northwest National Laboratory. A rapid, accurate and precise method for the determination of Sr-89 and Sr-90 has been developed and tested at the Pacific Northwest National Laboratory (PNNL). A thermal-neutron irradiated highly enriched uranium (HEU) target was the source of fission products used in this study. Sr-89 and Sr-90 atom concentrations of the dissolved HEU target were determined by isotope-dilution thermal ionization mass spectrometry (ID-TIMS). An in-house gravimetrically-prepared mix of NBS-987 natural Sr standard and highly enriched Sr-84 tracer (IRMM-635) was added to the sample prior to chemical purification. The addition of this mixed tracer allows for quantification of both the amount of natural Sr present in the sample (from either its presence in the HEU target or subsequently added during chemical purification/handling) and the Sr-89 and Sr-90 fission products. In parallel to the ID-TIMS assay, Sr-89 was measured by liquid scintillation counting (LSC) and inductively coupled plasma optical emission spectrometry. Initial results and statistical analysis of the ID-TIMS measurements yield precision approximately 10-times better than current LSC methods utilized at PNNL. A comparison of the radio-strontium measurements by ID-TIMS and LSC will be presented along with additional high-yield fission products measured by traditional radiometric counting methods. Log 461. THE FUTURE OF RADIONUCLIDE AEROSOL MONITORING SYSTEMS. Miley, H.S. (1); Biegalski, S.R. (2); Burnett, J.L. (1); Eslinger, P.W. (1); Forrester, J.B. (1); Haas, D.A. (3); Morris, S.J. (1); Willet, J.A. (1). (1) Pacific Northwest National Laboratory. (2) Georgia Institute of Technology. (3) University of Texas at Austin. Over two decades ago, a large volume, automated Radionuclide Aerosol Sampler/Analyzer (RASA) was first reported in the literature1, capable of about 10 micro Bq/m3 minimum detectable concentration of 140Ba on a 72 hour-long sample/decay/measure cycle. In the intervening years, hundreds of RASA-years of data and experience have accumulated, Fukushima lessons have been learned, and new monitoring research has been done. All of these bear on the role that system is intended to play: how sensitive it needs to be to detect the minimum interesting nuclear release, the degree to which a sparse network of such systems can locate and estimate the size of a radionuclide source, and how resilient and capable it needs to be to give useful service during a major nuclear release. Three key factors are sensitivity, sample collection time, and power consumption. The authors will discuss these analyses and the impact they make on goals for a future aerosol monitoring system. Log 462. RECENT DEVELOPMENTS IN THE RADIOCHEMISTRY EDUCATION PROGRAM AT THE UNIVERSITY OF TEXAS AT AUSTIN. Haas, D.A. (1); Pasman, M.E. (1); De Luna, B.A. (1); Barth, B.S. (1); Landsberger, S. (1). The University of Texas at Austin. The radiochemistry education program at The University of Texas at Austin has been developed over the last 15 years, beginning with the Radiochemistry Education Award Program (REAP) in 2002. The current energy in the program is a result of the 2017 Nuclear Forensics Research Award (NFRA) from the Department of Homeland Security - Domestic Nuclear Detection Office. Three aspects of the program have been impacted: student research, undergraduate and graduate course material, and a summer research experience program for underrepresented students.


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Log 463. EUV LASER IONIZATION MASS SPECTROMETRY FOR ACTINIDE ANALYSIS. Duffin, A.M. (1); Rush, L.A. (2); Menoni, C.S. (2). (1) Pacific Northwest National Laboratory. (2) Colorado State University. The defining characteristics of nuclear materials occur at various spatial scales. Detailed analysis requires probes that can match the spatial scales of those characteristics. The recent application of extreme ultraviolet (EUV) lasers for ablation/ionization coupled to mass spectrometry has proven a powerful new tool for analysis of solid actinide materials at the nanoscale. In this report, we will present recent data showing the performance characteristics of EUV laser ionization time-of-flight mass spectrometry for nanoscale analysis of nuclear material. Beyond spatial resolution, the main advantages of this developing analytical technique include excellent sample utilization efficiency and reduced molecular interferences compared with secondary ion mass spectrometry. EUV ionization mass spectrometry can become a potent new analytical tool to characterize nuclear materials at the micro and nano scales. Log 464. AUSTRALIA'S NUCLEAR WEAPON TEST LEGACY - RADIOLOGICAL PARTICLE CHARACTERISTICS AND UPTAKE INTO MARINE AND TERRESTRIAL WILDLIFE. Child, D.P. (1); Johansen, M.J. (1); Hotchkis, M.A.C. (1); Ikeda-Ohno, A. (2). (1) ANSTO, Australia. (2) HZDR, Germany. Radiological contamination from nuclear weapon tests has left an indelible signature on earth's terrestrial and marine environments, which is elevated in the marine and terrestrial organisms that live near former weapons test sites. The activity levels of the fission and neutron-activation products at the test sites have been steadily decreasing over time. However, plutonium (Pu) remains persistently elevated in site soils, sea sediments, beach sands, and biological tissues of wildlife. This contamination, predominantly dispersed as discrete radioactive particles, retains chemical form, morphology, speciation and isotopic content characteristic of the detonation scenario as well as the prevailing geology at the test site. This in turn dictates the weathering and release rates of the Pu from the particulate contamination and the potential for bio-accumulation into the affected biosphere. Australia was host to 12 low-yield nuclear surface tests at Maralinga and Emu Field in South Australia and the Montebello islands in Western Australia. In addition there were a number of 'safety trials' conducted at Taranaki, Maralinga, involving the explosive dispersal of approximately 22 kg of plutonium and uranium. To better understand the long-term fate of the Pu, radioactive particles have been collected , isolated and characterised from all of the Australian test sites using techniques including PSL-autoradiography, SEM, Synchrotron-XFM, alpha/gamma spectrometry and Accelerator Mass Spectrometry. In parallel the transfer of radio-isotopes from soil/sediment contamination into select species at several sites has been documented. Particle composition at the studied sites and related bio-uptake by organisms living in contaminated areas will be discussed. Log 465. REMOTE SENSING (Li-U) VOLATILITY FOR NEW SIGNATURES FROM UNDERGROUND NUCLEAR EXPLOSIONS. Carman, A.J. (1); Liezers, M. (1); Eiden, G.C. (1). (1) Pacific Northwest National Laboratory. The detection of radioactive noble gas isotopes is one of the key tools in detecting underground nuclear explosions but other volatile radioactive species may also migrate to the surface that have historically been overlooked. To investigate this possibility we have been studying which elements are most readily volatilized into air from solid materials (rocks, concrete, glass etc.) following short duration (60-120 sec) spot heating spanning a wide temperature range (100-2000 °C). The widest possible range of elements (Li-U) were monitored during the experiments that produced some unexpected results with regards to the apparent atmospheric persistence of some volatilized elements long after heating had ceased and the sample had returned to room temperature. Results highlighting elemental volatility as a function of temperature from different materials will be presented along with examples illustrating the extended periods over which some elements remain detectable by atmospheric sampling.


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Log 466. MEDICAL ISOTOPE PRODUCTION, RESEARCH REACTORS AND THEIR CONTRIBUTION TO THE GLOBAL XENON BACKGROUND. Hoffman, I. (1); Berg, R. (1). (1) Radiation Protection Bureau, Health Canada. The Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans the testing of nuclear devices underground, in the atmosphere and underwater. Two main technologies, radionuclide and seismo-acoustic monitoring, are used for the verification of the CTBT. This paper focuses on radioactive noble gas monitoring and some of the discrimination challenges presented by civilian activities including medical isotope production and research reactor operations. Medical isotope production from fission-based processes is a dominant contributor to a worldwide background of radioxenon. This background can make the discrimination of nuclear tests from legitimate nuclear activities very challenging. Even if emissions from medical isotope producers experienced a large reduction, there remain other important sources of radioxenon that contribute to the global background such as research reactors and nuclear power plants. Until recently, the largest producer of medical isotopes was located in Canada, at the Canadian Nuclear Laboratories (CNL) facility. The characterization of CNL emissions and its research reactor can provide valuable information for effective verification of the CTBT. Log 467. ULTRA-TRACE LEVELS OF URANIUM AND THORIUM IN ELECTROLYTIC COPPER. Benedik, L. (1); Pilar, A.M. (2); Prosen, H. (2); Jačimović, R. (1); Povinec, P.P. (3). (1) Jožef Stefan Institute, Slovenia. (2) University of Ljubljana, Slovenia. (3) Comenius University, Slovakia. Uranium and thorium as natural radioactive elements are present everywhere in the environment. Their ultra-trace levels are also present in a cooper which is used as a shielding material in gamma-ray spectrometry, located very close to the detector. Ultra-low level of uranium and thorium in electrolytic copper were determined by radiochemical neutron activation analysis via their induced nuclides U-239/Np-239 and Pa-233, respectively. After irradiation of cooper together with uranium and thorium standards, various separation techniques were used for their separation from the matrix. For isolation of short-lived U-239 solvent extraction in combination of TBP and toluene was used, while for separation of Np-239 and Pa-233 extraction chromatography by using TEVA and TK-400 resins were applied. A special attention was paid on the estimation of radiochemical recovery, which was determined in each sample aliquot by using U-235, Np-238 and Pa-231. For quantification of induced nuclides and tracers used in the experiment gamma-ray spectrometry was applied. Results obtained showed that electrolytic copper contains impurities of uranium and thorium in ultra-trace levels; up to 45pg/g (550 nBq/g) for uranium and up to 80 pg/g (330 nBq/g) for thorium. The electrolytic copper contains also impurities of Ag, Au, Sb, Se and Zn as observed using the k0 INAA technique. Log 468. WHAT CONSTITUTES AN ANOMALY? CONSIDERATION OF RECENT ATMOSPHERIC RADIONUCLIDE SIGNALS NEAR DPRK. Miley, H.S. (1); Bowyer, T.W. (1); Burnett, J.L. (1); Cooper, M.W. (1); Eslinger, P.W. (1); Foxe, M.P. (1); Hayes, J.C. (1); McIntyre, J.I. (1); Schrom, B.T. (1). (1) Pacific Northwest National Laboratory. In the classic mode of monitoring, radionuclide experts looked for one or more strong downwind detections with meaningful ratios of radioactive species. However, today's reality is very sparse networks of radionuclide monitoring stations looking for weak signals, and expected to discriminate ordinary background from specific nuclear explosion signals. Individual measurements may produce signals at or above the Minimum Detectable Quantity, atmospheric backtracking may indicate interesting source locations (eg. suspected or known emitters), and ratios may be interesting, but the detected event might still not be anomalous. The authors will present some analyses of aerosol and xenon signals potentially related to the September 2017 announced DPRK nuclear test and others, and consider the strength of expressions like "anomalous" and "is consistent with". These expressions require history and the consideration of multiple hypotheses to be meaningful.


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Log 470. APPLICATIONS OF MP-1 ANION EXCHANGE RESIN AND EICHROM LN RESIN IN BERKELIUM-249 PURIFICATION. Du, M. (1); Tan, R. (2); Boll, R. (3). (1) ORNL. (2) University of Tennessee at Knoxville. (3) ORNL. Production of Berkelium -249 (249Bk, half-life 330 days) requires Cm target fabrication and five months of reactor irradiation in the High Flux Isotope Reactor (HFIR). The irradiation is followed by a multi-step post-irradiation campaign, which takes about six months before the 249Bk product is purified. Current processing steps include Aluminum Dissolution, Nitric Dissolution, CLEANEX, twice LiCl Anion Exchange, Hydroxide Precipitation, AHIB Cation Exchange, and finally 249Bk Finishing. The peak yield of 249Bk is at the reactor discharge, since no ingrowth 249Bk occurs afterwards, which means the shorter the processing time the higher amount of the 249Bk produced. Trials of using single column of either LN resin or MP-1 anion exchange resin were performed at Radiochemical Engineering Development Center (REDC) of the Oak Ridge National Laboratory (ORNL), acquiring encouraging results of separating 249Bk selectively from other trans-Cm elements and fission product impurities. This dual column method has been proposed to replace the current process of "Bk Finishing" and thus shorten future 249Bk campaigns by about two months. This presentation will include the experiment results of 249Bk separation by using columns of LN and MP-1 resins. To further shorten the campaign period, possibilities of using this method ahead of AHIB Cation Exchange, or even ahead of LiCl Anion Exchange will also be discussed. Log 471. DEVELOPMENT OF MICROFLUIDIC DEVICES FOR SOLVENT EXTRACTION STUDIES AND RADIOANALYTICAL APPLICATIONS. Gelis, A.V. (1); Launiere, C.A. (1). (1) Argonne National Lab. A microfluidic system has been developed for measuring the kinetics of metal ion extraction under conditions that are relevant to used nuclear fuel reprocessing. This system determines individual absolute interfacial mass transport rate constants using off-line measurements for a range of nuclides (Americium, Lanthanides) extracted from a mixture while surface area, mixing rate, and other parameters were under total control. Furthermore, the high specific interfacial area enabled rapid rates of reaction, which is especially valuable for reactions with high rate constants because it i) allows the measurement of the extent of reaction from short contact times to equilibrium; and ii) allows the measurement of true rate constants that are not obscured by mixing or diffusion limitations. In addition, a droplet-based microfluidic chip with redox control capabilities was successfully tested for Uranium - Plutonium separation in the nitric acid - tributyl phosphate liquid-liquid solvent extraction system. Log 472. THE SEARCH FOR SUPERNOVA DERIVED 244Pu ON PLANET EARTH. Gajos, N.A. (1); Springer, K.W.E. (1); Noyes, K.L. (1). (1) Pacific Northwest National Laboratory. Natural (non-anthropogenic) 244Pu is produced during r-process nucleosynthesis. The r-process occurs during core collapse supernova, and it produces half of all nuclides in the universe heavier than iron. 244Pu produced in supernovae mixes with interstellar medium (ISM) and subsequently rains down onto Earth in the form of ISM dust particles. We intend to answer whether or not we can detect supernovae derived 244Pu on planet Earth and if we can distinguish it from anthropogenic (fallout derived) 244Pu. The answer to these questions will shed light on the frequency of r-process nucleosynthesis in our galaxy and the nature of heavy element production in our universe. ISM dust particles accumulate on Earth in deep sea reservoirs. Previous Pu analyses of deep sea manganese nodules have revealed the presence of 244Pu in these nodules (Wallner et al., 2015). We analyzed 30g of NOD-P, USGS manganese-nodule reference material. The sample was spiked with a 242Pu tracer and analyzed on the Thermo Triton TIMS. Results indicate a concentration of 8.2 fg/g Pu in NOD-P and the following isotopics: 240Pu/239Pu = 0.14788 ± 0.00086 2σ, 241Pu/239Pu = 0.000645 ± 0.000096 2σ and 244Pu/239Pu = 0.000117 ± 0.000059 2σ. Isotopic data from NOD-P indicates a large anthropogenic contribution that is consistent with fallout from atmospheric nuclear weapons testing. Future analyses will focus on a well characterized manganese crust, ARIES-15D, from the western Pacific Shatsky Rise. Targeted depth profile sampling will allow us to discriminate the surficial anthropogenic signature (239Pu, 240Pu, 241Pu) from the supernovae signature (244Pu) at depth.


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Log 473. DETERMINATION OF TRANSMUTED HELIUM IN IRRADIATED NUCLEAR REACTOR MATERIALS BY VACUUM FUSION MASS SPECTROMETRY. Shi, Y. (1); Leppinen, J. (1); Macleod, R. (1). Canadian Nuclear Laboratories, Canada. Nickel-based alloys, with their superior properties of high-temperature strength, toughness, and creep and corrosion resistance, are used as component materials in nuclear power reactors, and proposed for Gen-IV reactors, fusion reactors, and neutron spallation sources. Neutron radiation can affect the mechanical properties and microstructure of the nickel based alloys; causing damage to the alloys. For example, the fuel channel spacers in CANDU reactors, made of Inconel X-750, become brittle with increasing operating time. It is believed that direct displacement of atoms and gas generation from nuclide transmutations are the two principle mechanisms causing neutron irradiation damage. While displacement damage occurs mostly with fast neutron collision cascades, transmutation of 58Ni to 59Ni followed by 59Ni(n, α)56Fe and 59Ni(n, p)59Co reactions by thermal neutrons generates most the helium and hydrogen and accelerates the void swelling. Void swelling, causing material embrittlement, is a great concern for commercial reactors where neutron dose is usually high to the structure materials. Therefore research into the fundamentals of neutron radiation damage through helium/hydrogen generation in nickel-based alloys is needed for the assessment of reactor component lifetime. For such research activities, development of analytical methods to measure the He and/or H content in irradiated and highly radioactive nickel alloy materials is essential. A vacuum fusion – mass spectrometry (VF-MS) method for determination of helium in irradiated nickel alloys specimens has been developed at Canadian Nuclear Laboratories (CNL). Using test specimens in a mass range from 0.01 to 0.05 g and a radioactivity range from 0.002 to 0.06 Ci·g-1 of 60Co, the key experimental parameters, fusion time and temperature, have been optimized for the complete extraction of helium in a Pt-Sn flux. Both standard calibration and isotope dilution mass spectrometry (IDMS) methodologies have been applied to quantification of the extracted helium. The results obtained from these test samples agreed well with the predicted values and with the analysis performed at a secondary independent laboratory. This research provided the technical bases for further development of this capability to analyzing highly radioactive materials up to 3 Ci·g-1 of 60Co activity at CNL to support the research and operation needs from both internal and external customers. Log 474. OBSERVATION OF HALIDES IN URANIUM OXIDE MATERIALS BY LARGE GEOMETRY SECONDARY ION MASS SPECTROMETRY. Williamson, T.L. (1); Tenner, T.J. (1). (1) Los Alamos National Laboratory. Large Geometry Secondary Ion Mass Spectrometry (LG-SIMS) has the ability to deliver in-situ high precision and accuracy isotope ratios of individual particles, and is routinely used in nuclear forensics analyses to look for distinct isotopic populations of particles within samples. As is common with many other nuclear forensics analyses, uranium is the chief analyte of interest for forensic analysis by SIMS, but it is not the only signal that can be measured. Halide based chemistries are often involved in the processing of nuclear materials, for example chlorine or fluorine based chemicals. Analysis of halides by common analytical techniques is often limited by poor detection limits. Analysis of halides by high precision, low detection limit conventional mass spectrometry techniques is challenging since halides prefer to form a negative ion, which are not usually able to be measured by mass spectrometry. For SIMS however, analysis of negative ions is routine and commonly done for light stable isotopes such as O, N, and C. Since halides readily form stable negative ions, they have excellent ionization efficiency by SIMS, and can be measured at the individual particle level with excellent detection limits. We will discuss measurements of halides on uranium oxide particles that have been processed in different ways, revealing distinct halide signatures and multiple halide populations within samples. We will demonstrate that halide analysis by SIMS is relatively straightforward and may offer a promising secondary analytical signature for nuclear forensic analysis of uranium particles.


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Log 475. SPECTROELECTROCHEMISTRY AS A STRATEGY FOR IMPROVING SELECTIVITY OF SENSORS FOR NUCLEAR WASTE APPLICATIONS. Heineman, W.R. (1); Branch, S.D. (1, 2); Bryan, S.A. (2). (1) University of Cincinnati. (2) Pacific Northwest National Laboratory. Spectroelectrochemistry provides improved selectivity for sensors by electrochemically modulating the optical signal associated with the analyte. The sensor consists of an optically transparent electrode (OTE) coated with a film that preconcentrates the target analyte. The OTE functions as an optical waveguide for attenuated total reflectance (ATR) spectroscopy, which detects the analyte by absorption. Alternatively, the OTE can serve as the excitation light for fluorescence detection, which is generally more sensitive than absorption. The analyte partitions into the film, undergoes an electrochemical redox reaction at the OTE surface, and absorbs or emits light in its oxidized or reduced state. The change in the optical response associated with electrochemical oxidation or reduction at the OTE is used to quantify the analyte. Absorption-based sensors for metal ion complexes such as [Fe(CN)6]4- and [Ru(bpy)3]2+ and fluorescence-based sensors for [Ru(bpy)3]2+, [Tc(dmpe)3]2+, and the polycyclic aromatic hydrocarbon metabolite, 1-hydroxypyrene, have been developed. The sensor concept has been extended to binding assays for a protein using avidin-biotin and 17.-estradiol-anti-estradiol antibodies. Sensing platforms have been demonstrated to measure metal complexes in complex samples such as nuclear waste and natural water and have been extended to the measurement of the non-pertechnetate form of technetium in a real waste sample from tank 241-AN-102 at the Hanford Site in southeastern Washington. Log 476. TARGET PREPARATION BY HIGH VACUUM EVAPORATION. Bond, E.M. (1); Roman, A.R. (1); Zhao, X. (1); Bredeweg, T.A. (1). (1) Los Alamos National Laboratory. The ability to prepare thin, uniform actinide targets is essential for nuclear physics experiments. Likewise, the preparation of uniform thin films of stable elements is of interest. Stable elements will be used either as targets for nuclear physics experiments or as a containment for highly radioactive target materials such as Pu. For these reasons, we have acquired a Denton Vacuum DV-502 Thermal Evaporation system. We will discuss the preparation of stable targets (Au, Cu) on a variety of substrates such as Ti, Mylar, and C foil. We will also discuss the preparation of actinide fluorides and their use in the production of actinide thin films. The uniformity and chemical composition of the resulting films will be discussed. LA-UR-17-31369 Log 477. CHARACTERIZATION OF NEUTRON SPECTRA FROM A (30 MEV D, BE) SOURCE USING THE MULTI-FOIL ACTIVATION TECHNIQUE. Goodell, J.J (1); Egnatuk, C.M. (2); Padgett, S.W. (2); Bandong, B.B. (2); Roberts, K.E. (2); Mignerey, A.C. (1). (1) University of Maryland. (2) Lawrence Livermore National Laboratory. A well-defined neutron spectrum is vital for generating and evaluating nuclear data as well as performing activation, radiography, or radiation effects experiments. Of the possible neutron generation methods, accelerator-driven neutron sources are uniquely suited for applications requiring fast neutrons because of their ability to provide broad neutron spectra at high energies. Use of accelerator-driven neutrons also offers the advantage of adjusting the neutron spectrum for specific applications by changing the accelerated ion beam energy, thus making accelerator sources much more versatile. The 76-inch cyclotron at the University of California-Davis Crocker Nuclear Laboratory is an example of such a source, utilizing the d+Be family of neutron-sputtering reactions to produce neutrons. To date, little has been done to properly characterize this neutron source. This work seeks to generate a well-defined neutron spectrum, produced by a 30 MeV deuteron beam interacting with a Be target converter, using the multi-foil activation technique and the SAND-II-SNL neutron spectrum unfolding code. Al, Au, Co, Cr, Cu, Fe, Ir, Ni, Pt, Ti, W, and stainless steel activation foils were irradiated with neutrons sputtered from the Be target converter when hit with a 30 MeV deuteron beam at 10 uA particle current. The unfolded spectrum is compared against historical data and a Monte Carlo simulated spectrum from a MCNP6.1 model of the experimental setup. Activation rates for selected reactions are compared between the unfolded, modeled, and historical neutron spectra. Differences in reaction rates are highlighted by the comparison of activation yields in a stainless steel foil.


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Log 478. EXPERIMENTAL MEASUREMENT AND INDIRECT ASSESSMENT METHODS TO DETERMINE THE NATURAL BACKGROUND GAMMA RADIATION DOSE RATE IN URBAN REGION. Hoang, S.M.T. (1); Tran, H.N. (1); Sun, G.M. (2); Kim, J.S. (2); Lee, K.M. (2); Tran, D.K. (3). (1) Duy Tan University. (2) Korea Atomic Energy Research Institute. (3) Dalat Nuclear Research Institute. The maps of dose rate have been composed to the Ho Chi Minh City (Vietnam) including the natural background gamma radiation at the altitude of 1 m above the ground, the accumulated dose of environmental gamma radiation, and radioactivity of the main natural and human-made radioisotopes in soils. It is adopted to estimate public exposure as well as having a database for impact assessment from an environment. In this study, three methods were applied as an environmental radiation monitoring system with GPS, determination of dose-rate component methods, and cumulative dose monitoring. With the first one, the mobile monitoring system installed on a box type vehicle contains the radiation measuring instruments of gamma-ray dose rate monitor (Model FH-40-Eberline), data processing unit, GPS, etc. The second one was an indirect method through to the collection and analysis of gamma radiation from radioactive isotopes in soil: Collect and determine the specific activity of natural radioactive isotopes and artificial soil, thereby applying the system dose conversions and specialized software to calculate the radiation dose outside projection, and a Thermoluminescent Dosimeter (TLD) was used in the last method. The resulted values were widely fluctuated in the range from 0.05 to 0.18µSv/h, with the average value of 0.10 mSv/h. Approximately, there are 86.2% of the obtained dose rates within the range from 0.08 to 0.12 µSv/h equivalent to 0.70 to 1.05 mSv/year, and this range is in agreement with the natural radiation background in the whole world. The average values were as 33.1, 21.1, 36.6, 279.0, and 0.42 Bq/kg. Log 479. SIMULATING THE EFFECTS OF AN UNDERGROUND NUCLEAR EXPLOSION WITH AN EXPLODING WIRE. Liezers, M. (1); Carman, A.J. (1); Eiden, G.C. (1). (1) Pacific Northwest National Laboratory. Exploding wires can deposit significant amounts of energy (1000's of Joules on a nano-microsecond timescales) into a very confined space. Under the right conditions they can even produce neutrons. While most exploding wire studies have been performed in open air and to a lesser extent liquids we have started to investigate enclosing the wire element in solid matrices like concrete to mimic the effects of an underground nuclear explosion. The temperatures and pressures achieved are quite sufficient to induce structural cracking and localized flash melting in the enclosing media like a real underground nuclear detonation. As a result exploding wires would appear to form the perfect trigger for releasing confined chemical species including gases in geological media to study migration behavior in a controlled environment. Details of the apparatus and some illustrations of it potential will be given. Log 480. ENHANCING ANALYTICAL RESULTS OF GAMMA-RAY SPECTROSCOPY BASED ON GOLD DECONVOLUTION ALGORITHMS. Hoang, S.M.T(1); Tran, H.N.(1); Sun,G.M.(2); Kim,J.S.(2); Lee, K.M. (2); (1) Duy Tan University. (2) Korea Atomic Energy Research Institute. In this study, the quality of analytical results obtained from HPGe spectroscopy has been enhanced with the help of a Gold algorithm (GA). The GA has demonstrated its capacity in purifying a collected low-energy spectrum that was to eliminate the linear instability of the measuring equipment. For generating the matrix of response functions utilizing in the devolution process, the EGS5 code was adopted in simulations the response functions of the ORTEC HPGe spectroscopy system (Model GMX40-76 with a PopTop type having relative efficiency 40% and FWHM 1.95 keV at the 1.33 MeV peak of Cobalt-60). The results of Environmental Reference Materials (NIST, SRM 1646a, NIST SRM 1400, IAEA-395, and IAEA-450) were re-analyzed based on the GA, and compared with its certificate to estimate the performance of these improvements. In addition, the experimental samples were carried out with and without applying the GA and presented the average of different ratios about 15%. This study confirmed the capacity and confidence of the GA application in improving the results of gamma-ray spectroscopy systems.


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Log 481. INNOVATIVE DESIGN OF TIME-OF-FLIGHT PROMPT GAMMA ACTIVATION ANALYSIS SYSTEM USING MONTE CARLO SIMULATION CODES. Hoang, S.M.T. (1); Tran, H.N. (1); Sun, G.M. (2); Kim, J.S. (2); Lee, K.M. (2). (1) Duy Tan University. (2) Korea Atomic Energy Research Institute. Cold Neutron Prompt Gamma Activation Analysis (CN-PGAA) is a traditional prompt gamma activation analysis station but uses cold neutrons that provide different contrast among atoms compared to the thermal neutrons. A disk chopper taken up the end position of the CG2B guide is being installed to upgrade the performance of Cold Neutron PGAA system of CONAS (HANARO, Republic of KOREA) for alleviating some persistent problems in the PGAA method, which are inherent limitations and uncertainties from the PGAA method such as gamma-ray backgrounds, the overlap of decay lines, and unexpected lines appearing in the measured spectra. A beam of a polychromatic cold neutron was chopped into the short and discrete pulses of neutrons by using a rotating disk chopper. The solution is Monte Carlo simulations (MCNP6 and PHITS) as a primary key for speeding up design work and system optimization. The infuence of the di.erent parameters on the specific count rate from an element can be established by the simulation. In this study, Monte Carlo ray-tracing code (McStas) was applied to design and optimize the velocity and the aperture to close ratio of the disk chopper, while predicting the performances of the PGAA system in the coincidence and anti-coincidence modes based on Monte Carlo neutron particle transport code (MCNP6). As the results, the radius of the disk to the midpoint of the slits and the aperture to close ration were 21.5 cm and 1:130 that will be used to manufacture the disk chopper. The simulation results were shown to reduce peak interference and to increase the signal-to-background ratio for certain species in order to facilitate accurate elemental identification. Log 482. CONSTRAINING FALLOUT FORMATION PROCESSES BY MAJOR AND TRACE ELEMENT ANALYSES OF SYNTHETIC FALLOUT GLASS. Wimpenny, J.B. (1); Knight, K.B. (1); Marks, N.E. (1); Eppich, G. (1); Leever, M. (1). (1) Lawrence Livermore National Laboratory. Entrained soil is a key component of fallout melt-glass from near-surface nuclear tests. Recent studies suggest that soil melting, agglomeration and evaporative loss are important mechanisms in near-surface fallout formation, while others have proposed that vapor condensation may be dominant. To evaluate these competing mechanisms, we synthesized fallout-like glass in the laboratory, and compared composition variations in these materials with observations in historic fallout. We present new major and trace element data for silicate glasses formed from a uniform composition, soil-derived powder, at temperatures of 1600-2200 °C for heating durations of 1-120 seconds. Relative to the composition of the starting soil, the synthesized glass spheres became increasingly chemically fractionated with increasing temperature and time. More volatile elements such as K, Na and Pb are depleted, and as a result more refractory elements such Al, Ca, and the REEs are relatively enriched. This pattern of volatile element depletion was observed in all experiments, similar to patterns of major and trace element loss in historic fallout melt-glass. These results are consistent with entrained soil dominating the major and trace element inventory of near-surface fallout, and differences between the composition of entrained material and that of fallout melt glass are best explained by a mechanism of melting, agglomeration and evaporative loss. Prepared by LLNL under Contract DE-AC52-07NA27344. LLNL-ABS-743295 Log 483. BIS-(2-ETHYLHEXYL) PHOSPHORIC ACID IMPREGNATED ORDERED MESOPOROUS CARBONS FOR EUROPIUM RECOVERY. Bertelsen, E.R. (1); Kluherz, K. (1); Deodhar, G. (1); Davidson, M. (2); Adams, M. (1); Trewyn, B.G. (1, 2); Shafer, J.C. (1, 3). (1) Department of Chemistry, Colorado School of Mines. (2) Material Science Program, Colorado School of Mines. (3) Nuclear Science and Engineering Program, Colorado School of Mines. Ordered mesoporous carbon (OMC) materials physisorbed with bis-(2-ethylhexyl) phosphoric acid (HDEHP) have been investigated as a potential chromatographic material for fission product separations. HDEHP is a commonly used organophosphorus extractant, demonstrating a high selectivity of five orders of magnitude across the lanthanide series. The small mesh size, uniform morphology and high surface area of the HDEHP physisorbed OMC materials could make them an attractive candidate for chromatographic separations. The aforementioned properties have the potential to increase chromatographic resolution, ligand loading capaciy


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and sorption kinetics. Two HDEHP-OMC materials were compare against the LN Resin from Eichrom for the recovery of europium from acidic media. The maximum adsorption capacity of the materials under static, batch mode, and dynamic, column mode, conditions were assessed. HDEHP-OMC materials have a higher uptake of europium than the LN Resin at all acid concentrations considered. A Langmuir isotherm was used to show that the HDEHP-OMC materials provide nearly twice the maximum adsorption capacity. Pending result should consider the separations efficacy of the HDEHP-OMC materials for rare earth metals. Log 484. ENHANCED UTILITY OF AMINOPOLYCARBOXYLATES FOR TRIVALENT f-ELEMENT DIFFERENTIATION. Heathman, C.R. (1); Grimes, T.S. (1); Bryantsev, V.S. (2); Jansone-Popova, S. (2); Zalupski, P.R. (1). (1) Aqueous Separations and Radiochemistry, Idaho National Laboratory. (2) Chemical Sciences Division, Oak Ridge National Laboratory. Aminopolycarboxylates are used as aqueous complexants for trivalent f-element group differentiation in liquid-liquid separation schemes of used nuclear fuels. The separation efficiency of aminopolycarboxylates based on diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) is only rivaled by reorganization energy of the complex dissociation, resulting in kinetic limitations that hinder attainment of thermodynamic equilibrium of liquid-liquid systems. In an effort to improve on the efficacy of aminopolycarboxylates to liquid-liquid systems, a series of aminopolycarboxylate modifications have been carried out on ethylenediamine and diethylenetriamine platforms to perturb complex dissociation energetics. Thermodynamic and coordination characterization of the new series of complexants reveals insight into the tune ability of aminopolycarboxylate complexants and their role in developing improved f-element separations schemes. The utility of modified aminopolycarboxylate complexants in liquid-liquid solvent extraction systems were evaluated using radiometric time dependent metal ion liquid-liquid extractions to reveal surprising boosts to metal ion transport efficiency and group lanthanide/actinide differentiation. This contribution evaluates modified aminopolycarboxylates as holdback complexants for overcoming liquid-liquid solvent extraction challenges and relates structural modification to the perturbation of thermodynamic properties for the development of improved separation schemes. Log 485. ACTIVATION PRODUCT INTERPRETATION OF FLATTOP CRITICAL ASSEMBLY MEASUREMENTS. Keith, C.C. (1); Selby, H.D.(1); Lee, A.S.(1). (1) Los Alamos National Laboratory. This work evaluates whether activation products in stainless steel components can be used to infer initial conditions (i.e. alloy composition, positioning within the fluence, etc.) and the associated uncertainties in a fast neutron irradiation. Activation measurements of stainless steel and elemental components were obtained through a NA-22 sponsored Flattop critical assembly irradiation. A forward model was developed, utilizing MCNP6.1 and FISPACT ii, to estimate activation product concentrations from several input parameters: alloy composition, source specifications, and foil positioning. While some of the calculated activation product concentrations agreed fairly well with measurements, some isotopics (i.e. 57Co) had large discrepancies. It became clear that uncertainties in both measurements and nuclear data drove this divergence for select isotopics, and the quantification of this impact was needed. By treating both experimental measurement and nuclear data uncertainty in a Bayesian methodology, it was possible to infer unknowns from given activation ratios. The developed approach showed promise in constraining mass parameters, but degeneracy existed when considering position within the neutron flux. Higher threshold reactions could potentially break the degeneracy, such as 57Co, but uncertainty estimation needs to be better resolved for those isotopes.


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Log 486. EVALUATION AND REQUIREMENTS FOR SCALE FACTORS FROM EMRP PROJECT METRODECOM. Jerome, S.M. (1); Boden, S. (2); Capogni, M. (3); de Felice, P. (3); Ivanov, P. (1); Kovář, P. (4); Šmoldasová, J. (4). (1) National Physical Laboratory, UK. (2) Studiecentrum voor Kernenergie • Centre d'Étude de l'énergie Nucléaire, Belgium. (3) Agenzia Nazionale per le Nuove Tecnologie, l'Energia e lo Sviluppo Economico Sostenibile, Italy. (4) Český Metrologický Institut, Czech Republic. The EMRP project MetroDECOM, was concerned with research addressing all aspects of decommissioning process in order to deliver integrity and cost-effectiveness in support of clearance and disposal processes and improving safety and accuracy. Activities included; characterisation of solid wastes, pre-selection, free release and repositories' monitoring, measurement of thermal power prior to repository storage, and monitoring of wastes and repositories in the long term. One of the work packages was concerned with the characterisation of materials present on decommissioning sites to improve the characterisation of materials and items at decommissioning sites, prior to disposal. Within this work package, work on scaling factors was aimed at applying the principles set out in ISO 21238:2007 (Scaling Factor Method to Determine the Radioactivity of Low- and Intermediate-Level Radioactive Waste Packages Generated at Nuclear Power Plants) to the measurement of contaminated areas in decommissioning sites. In this paper, we report the progress made under MetroDECOM in identifying decommissioning matrices of specific relevance to nuclear decommissioning within the EU and selecting priority hard-to-measure radionuclides for further study. Details of existing scale factors for these nuclides and matrices will be presented, along with an analysis of needs for future research and scale factor measurement. Log 487. CHANGES TO PROFICIENCY TEST DATA INTERPRETATION AND DATA REJECTION AT THE NATIONAL PHYSICAL LABORATORY. Jerome, S.M. (1). (1) National Physical Laboratory, UK. Changes to interpretation, evaluation and visualisation to radioactivity measurement exercises conducted by NPL are presented in this paper. Data submitted over the years has been of varying quality, and the first step in further analysis of participant data is to exclude ‘obvious’ outliers. What may constitute a ‘blunder’ may be debated, but for the purposes of this work, these are data that are quite obviously ‘wrong’, and an objective treatment is presented. Having identified and rejected all gross errors, outlier rejection is carried out on the remaining reported values and their uncertainties. This is an area of much debate, and differing methods for identifying outliers have been employed, such as Dixon’s Q outlier test; Grubbs outlier test; Chauvenet’s Criterion. For this work the use of Peirce’s Criterion was selected; the advantage of using Peirce’s Criterion is that it is based on finding the most probable distribution of data by rejecting one or more contributing values. The remaining data are tested via the ζ-test, z-test and RL-test (relative uncertainty). The outcomes from the three tests may be used to assign an overall score to a particular laboratory’s reported result. If the tests are assigned priorities in this order ζ-test > z-test > RL-test, and the z- and RL-tests are subdivided into pass or fail at the lower limit and pass and fail at the upper limit, then each test returns a simple binary result. The use and interpretation of these tests and scores will be described in detail in the paper.


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Log 489. ANALYSIS OF NPL RADIOACTIVITY PROFICIENCY TEST RESULTS 1989-2016 FOR H-3, Sr-90, Cs-134, Cs-137 AND Am-241. Jerome, S.M. (1). (1) National Physical Laboratory, UK. In 1989, the NPL was asked by the UK Department of Trade and Industry to organise a proficiency test of laboratories in the UK who were involved in the measurement of radioactivity. This was driven by the aftermath in the UK of the Chernobyl disaster, which led to an increase in the number of service providers who claimed to be able to measure radioactivity in the environment. The quality of data provided was, in some cases, extremely questionable and served only to confuse the general public. At that time, there were very few laboratories accredited to ISO 17025 (or its predecessors) for radioactivity measurement, and any proficiency testing that was carried out tended to be within small groups of laboratories for their own purposes. Since then, programmes for radioactivity measurement within the UK have utterly changed through the fragmentation of the nuclear industry in general and the movement of government funded measurement programmes from the public to the private sector. Furthermore, at least 30 organisations within the UK who are accredited for radioactivity measurements. To date, NPL has carried out 22 radioactivity measurement proficiency tests, covering 53 radionuclides, 8 different matrices and activity concentrations from ~0.6 to 200 000 Bq/kg; and ~14 000 individual results have been generated. The main purpose of this paper is to compare the results for some of the core radionuclides - H-3, Sr-90, Cs-134, Cs-137 and Am-241 - in aqueous samples matrices, where there is an assigned value, derived from absolute standards of radioactivity. Log 490. COMPARATIVE STUDY OF ELEMENTAL CHARACTERIZATION TECHNIQUES APPLIED TO A COMPLETE REE SEPARATION PROCESS WITH K0-NAA, ICP-MS, XRF AND MP-AES. Neisiani, M. (1); Turgeon, K. (2); Avazpour R. (1); Carrillo Garcia, A. (1); Azizi, D. (2); Latifi M. (1); Chaouki, J. (1); Chilian C. (1). (1) Polytechnique Montreal. (2) University of Laval. Analytical performance of k0-neutron activation analysis (k0-NAA), inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF) and microwave plasma atomic emission spectroscopy (MP-AES) were investigated, compared and selected for the characterization of the products generated by separation process for rare earth elements. REE-2 (CanmetMINING) certified reference material containing high concentration of rare earth elements was used for the evaluation of the accuracy of the analytical methods. Samples of a REE ore from a Quebec, Canada deposit is analysed at each step of the REE separation process. The mass balances of the results are presented as a second validation of the analytical methods. This paper presents the results of REE elemental analysis in different matrix: solid (minerals, hydroxides, chlorides) and liquid (aqueous and organic solution). An optimal analytical protocol is tailored for each separation process, combining the optimal choice of the characterization methods based on efficiency and accuracy of measurements. Log 491. GAMMA-RAY DETECTION EFFICIENCY MODEL FOR VOLUMETRIC SAMPLES. Hall, D. (1); Neisiani, M. (1); Chilian, C. (1). (1) Polytechnique Montreal. This paper proposes a novel correction method for the gamma-ray detection efficiency for samples packed in cylindrical vials based on the evaluation of the average path lengths within the sample. The well-established Gunnink model suggests that the gamma-ray emission is locally represented by a cone with the apex centered at the emission point and having energy-dependent geometric parameters imposed by the sample/detector geometry. The path-averaged distances between the apex and the intersection points formed by the cone and the sample's edges are determined numerically and thereafter these distances are averaged out within the sample volume for various fill factors and this, using cuboid discretization elements. In addition, the model implements edge effects due to finite cylinder and detector geometries. From an experimental standpoint, the model was validated with 182Ta gamma-rays from 68 to 1221 keV using cylindrical samples with 20 mm height and 10 mm inner radius. The samples were counted with the axis perpendicularly to the detector head axis, at distances of 8.8, 39.6 and 105.6 mm with respect to the detector. Using the numerical data, it is possible to obtain parametrization curves capable of correcting the beahviour in energy of the detection efficienty and resolving previously observed experimental discrepancies.


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Log 492. XENON/IODINE SEPARATIONS FOR RADIOACTIVE XENON ISOTOPE PRODUCTION. Robinson, T. (1); Brookhart, J. (1). (1) Idaho National Laboratory. Radioactive iodine is a hazardous by-product of some radioactive xenon isotope production techniques. Radioactive iodine must be removed from xenon to prevent contamination of detectors, and to protect workers from undesirable health effects. A separation method has been developed for removing radioactive iodine from radioactive xenon based on differences in elemental vapor pressure using Xe-135 and I-135 as radioactive tracers. This method has been applied to the purification of Xe-127 from I-125 and Xe-135 from I-135, and has also been used to remove water residue from xenon gas samples. This method can also be exploited to produce Xe-135 that has been removed from the carrier target gas from the collection of ingrown I-135. Log 493. REDUCTION OF Xe-133 AND Xe -133M IMPURITIES IN THE PRODUCTION OF Xe -135. Robinson, T. (1); Stoner, J. (2); Kinlaw, M. (1); Watrous, M. (1); Houghton, T. (1). (1) Idaho National Laboratory. (2) Idaho State University. Production of Xe-135 (T1/2 = 9.14 hrs) is easily done through neutron irradiation of an isotopically enriched Xe-134 target gas. Due to trace Xe-132 impurity in the target gas and undesirable (n, 2n) reactions, small amounts of Xe-133 (T1/2 = 5.2475 days) and Xe-133m (T1/2 = 2.19 days) are also co-produced. These undesirable radioactive impurities limit the useful lifetime of the Xe-135 produced due to their half-lives, which lead to increasing 133:135 and 133m:135 activity ratios over time. Efforts to obtain isotopically enriched Xe-134 gas with lower Xe-132 content showed improvement, but due to (n, 2n) reactions with the Xe-134, there still remains some Xe-133 and Xe-133m production. A parallel effort was made to produce Xe-135 using (gamma, n) reactions with an isotopically enriched Xe-136 gas. Additional improvement in the reduction of Xe-133 and Xe-133m production was observed using the (gamma, n) reaction path. Log 494. INITIAL UV-VIS/IR SPECTRSCOPY MEASUREMENTS OF SURROGATE NUCLEAR FIREBALLS. Auxier II, J.D. (1, 2); Francis, E.J. (1, 2); Nizinski, C. (1, 2); Starks, J. (1, 2); Hall, H.L. (1). (1) Department of Nuclear Engineering, University of Tennessee. (2) Institute for Nuclear Security. In the immediate seconds after the detonation of a nuclear weapon a large plasma cloud is formed. This plasma cloud has a unique environment due to the pressure and temperatures that are achieved. To simulate the high temperature efforts, collaborations between Oak Ridge National Laboratory have been leveraged to setup an industrial grade plasma torch. This work will leverage the existing collaboration and laboratory facilities to investigate the plasma chemistry in real time to determine what processes of formation (e.g. oxide, nitride, sulfide, etc.) occur in different regions of the plasma (e.g. edge, center, etc.) using chemical compositions for the fallout recipes derived using the methods developed previously. After particulate matter is formed in the plasma region, the experimental chamber is set up to collect samples for investigation by scanning electron microscopy (SEM) and other similar morphological and surface chemistry characterization techniques. This paper will detail the early measurements that have been made with UV-Vis/IR measurements for detection of elemental or ionized species.


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Log 496. DIAL-A-DEBRIS FISSION PRODUCT BLENDING TO PRODUCE GLASS SURROGATES FOR POST-DETONATION NUCLEAR FORENSICS. Bucher, B.M. (1); Carney, K.P. (1); Pfeiffer, J.K. (1); Kinlaw, M.T. (1); May, E.M. (1); Cardenas, E.S. (1); Finck, M.R. (1); Snow, M.S. (1). (1) Idaho National Laboratory. The ability to manipulate individual fission-product radioisotope concentrations in synthetic nuclear fallout debris samples has important applications to field exercises and laboratory validation needed for development of nuclear forensics capabilities. Freiling (1965) showed that radionuclide fractionation is important in air-burst debris. Carney (2013) demonstrated the creation of glass materials containing fractionated fission product distributions. The ability to selectively manipulate fractionation has recently been demonstrated at Idaho National Laboratory based on chemical separations of radioisotopes produced by photofission of an isotopically-enriched uranium-238 sample. The sample was irradiated by bremsstrahlung gamma-rays produced from 26 MeV electrons impinging on a tungsten converter. After a brief cooling period, the sample was dissolved and chemically processed to separate fission product isotopes of interest from the bulk uranium matrix. Following the separations, the fission products were then remixed and integrated into small glass spherules using sol-gel production methods. Gamma-ray spectroscopy was performed throughout the separations to ascertain the radioisotope concentrations at each stage, and to analyze the final glass product. Key effective fission product yields of the remixed, carrier-free glass were measured and found consistent with those produced in fast neutron fission of uranium-235, based on the standard barium-140 to zirconium-95 isotopic ratios. By choosing different remixing ratios, different effective fission product yield ratios can be achieved and the low processing temperature of the sol-gel technique allows for the controlled incorporation of volatile species. Trace quantities of actinides and activation products can also be incorporated into the matrix. Details of the experiment, analysis, and results from this measurement will be presented. Log 497. RAPID SPECTRAL ANALYSIS FOR COMPLEX GAMMA-RAY SPECTRA. Dayman, K. (1); Biegalski, S. (2). (1) Oak Ridge National Laboratory. (2) Georgia Institute of Technology. Gamma-ray spectrometry is a field-deployable, nondestructive analysis technique capable of determining the concentration of multiple analytes from a single measurement without time- and resource-intensive prechemistry. The wealth of information encoded in complex gamma-ray spectra requires numerous data analysis steps to resolve spectral interferences, interpret overlapping peaks, and perform multivariate pattern matching to identify gamma-emitting radionuclides within a sample. These analyses are highly correlated: analyzing spectral complexities such as interferences depends on the hypothesized sample composition, which may be updated as spectral features are resolved. Such analysis steps are often performed manually or in an ad-hoc fashion, which increases analysis time and uncertainty in results. In addition to the nuclide identification problem, gamma-emitting nuclides must be generally treated as decay chains continuously evolving in time. We have proposed and demonstrated the viability of a new gamma-ray spectra analysis method and have begun development of code capable of automatically populating potentially large decay chains of radionuclides and encoding the decay chain structure, nuclear data, and simplified detector response into a convex optimization problem. This novel method identifies the best-fit composition and concentration of gamma-emitting radionuclides using a formal statistical model that can account for poor counting statistics, analyze multiple spectra to exploit time-varying behavior of radionuclides, and treat multiple sources of uncertainty. Log 498. A COMPARISON OF NUCLEAR ACCIDENT PARTICLES. Cezeaux, J.R. (1); Varshney, G. (2); Petrosky, J.C. (2). (1) 711th Human Performance Wing, U.S. Air Force School of Aerospace Medicine. (2) Air Force Institute of Technology, Wright Patterson AFB. Nuclear weapon accidents have taken a number of forms over the years, ranging from fuel fires to aircraft crashes. The energetic processes associated with creation of particles in these events create a wide distribution of particle sizes and morphologies. This presentation of a work in progress compares particles from the BOMARC accident with those from an explosive safety test. The results indicate that there is an overlap in morphological characteristics and that a population-based approach, as opposed to single particle analysis, may hold more promise for determining characteristics of those particles resulting from non-critical nuclear weapon accidents.


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Log 499. APPLICATIONS OF BETA SPECTROMETRY IN THE SRNL NUCLEAR MEASUREMENTS GROUP. DiPrete, C.C. (1). (1) Savannah River National Laboratory. Waste cleanup efforts currently underway at the Savannah River Site (SRS), as well as other DOE nuclear sites, have created an ongoing need to characterize inventories of the Waste Tank heels prior to tank closure. The heels of each tank slated for closure often have unique chemical constituents and unique radiological distributions compared to previously characterized tank heels. Therefore, historical methodologies are often not applicable for new Waste Tank characterizations. The varied matrices among the tanks is complicated by an expanding list of radioactive isotopes requiring quantification with increasing sensitivity. As Tank Closure campaigns mature, additional isotopes are added to characterization lists. Many of the target isotopes are required to be quantified to extremely low levels in the presence of interferences that are up to 10 orders of magnitude greater than the isotope of interest. Historical methodologies which sufficiently decontaminate samples of interfering isotopes are often non-existent. Therefore, methodologies must be developed to meet the sensitivity needed for regulatory requirements. The combination of vastly different matrices among tanks along with increased sensitivity needs for many isotopes requires extensive method development for each Tank Closure radiological characterization program. Aggressive schedules for these programs require rapid method development. With a focus on beta-emitting isotopes, an overview of the methodology used to separate and quantify tank residue for Tank Closure radiological characterization programs will be discussed. The methodologies discussed will encompass customized dose-reducing preliminary separation steps carried out in shielded cells facilities through final separations in radiohoods and counting techniques. Log 500. AUGER-EMITTING Te-119/ Sb-119 GENERATORS FOR RADIOTHERAPY. Bennett, K.T. (1); Bone, S.E. (1); Engle, J.W. (2); Kozimor, S.A. (1). (1) Los Alamos National Laboratory. (2) Dept of Medical Physics, University of Wisconsin. The unique properties of the Sb-119 isotope, primarily associated with its versatile Auger and conversion electron emission, provide a high potential for use in personalized therapy of human disease. It is the short range of the electrons generated from the Sb-119 decay that are attractive, in comparison to higher energy electronic emissions from other radiotheraputic isotopes, which can cause systemic toxicity even if appropriately targeted. In this work, Te-119(m+g) is created through a (p,xn) irradiation of natural antimony in the low energy C-slot of the Isotope Production Facility at the Los Alamos Neutron Science Center. The separation occurs through the use of extraction based and ion exchange resins to yield a pure Te fraction, which contains no carrier added antimony. The tellurium fraction is used to generate Sb-119 through the decay of Te-119(m+g). Work was conducted at the Stanford Synchrotron Radiation Lightsource to gain insight into how the antimony/tellurium separation was occurring on the various resins and to better understand the species present and separation process. Through the use of the synchrotron, insight on the speciation and oxidation states antimony and tellurium was gained and this information aided in the understanding of the resin separations. With knowledge of the separation gained from the synchrotron based experiments, a full-scale separation was performed with an irradiated Sb target inside of hot cell facilities located at Los Alamos National Laboratory yielding a tellurium product free of antimony. LA-UR-17-27628 Log 501. GENERATING AERODYNAMIC SURROGATE NUCLEAR EXPLOSION DEBRIS (SNED). Carman, A.J. (1); Endres, M. (1); Liezers, M. (1); Eiden, G.C. (1). (1) Pacific Northwest National Laboratory. So called 'aerodynamic debris' has often been observed on the fringe of surface nuclear tests, and is assumed to result from ejection of melted and re-condensing ground material drawn up into the rising explosion fireball. The material forms small glassy particulates ~1mm ranging in shape from near perfectly spherical glassy beads to more elongated forms and occasionally agglomerates of two or more partially particles displaying some degree of fusion. Producing material with a similar range of forms in the laboratory may quite challenging as the temperatures required exceed 1500 °C while keeping the particulates suspended in air. In this paper we describe an apparatus that can heat lofted sediment particulates up to 1mm very rapidly to >2000 °C allowing interactions times from seconds to minutes. Examples of the material forms produced will be compared to real aerodynamic debris recovered from nuclear explosions described in the literature.


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Log 502. STATISTICAL EVALUATION OF MULTIVARIATE MEASUREMENTS FOR MATERIAL PROVENANCE ASSESSMENT. Dayman, K. (1); Weber, C. (1). (1) Oak Ridge National Laboratory. Predetonation nuclear forensics is primarily concerned with examining multinuclide assays of an interdicted material and matching the unknown material with a known material from a library based on these assays (i.e., classifying the interdicted material). Generally, little is known about the interdicted sample. Therefore, any successful classification method must be able to account for significant nuisance variation in composition when evaluating the similarity between unknown and known library material assays. In addition, nuclear forensics datasets are typically sparse and smaller than those in other machine learning contexts such as image analysis, where training data can include tens or hundreds of thousands of labeled images. To realize this capability, we use a multivariate generalization of quantile-quantile comparisons, termed geometric quantiles, to compare the distributions of nuclide isotopics in unknown and known samples. In addition, we are able to estimate the probability of misclassification by deriving the distributions for these geometric quantiles and employing methods of statistical hypothesis testing. Using this approach, we have performed statistical experiments using the newly released SFCompo 2.0 database of real-world irradiated material assay data to demonstrate the utility of our geometric quantile method. In these initial experiments, our method is capable of classifying irradiated fuel according the class of the reactor of origin. Log 503. Ra-226 ANALYSES ON SAVANNAH RIVER SITE RADIOACTIVE WASTE MATRICES. DiPrete, D.D. (1); DiPrete, C.C. (1); Reboul, S.H. (1); Hay, M.S. (1). (1) SRNL. Waste cleanup at the Savannah River Site, as well as other DOE nuclear sites, has created an ongoing need to characterize the radiological inventories of various waste tank heels prior to tank closure. Each tank heel has unique chemical and radiological distributions, rendering the use of routine analyses inadequate. Since each tank is a completely new matrix with often-unforeseen interferences, method development must be performed for each tank’s residue material. While currently representing only a small fraction of the activity in the various sites' radioactive waste inventories, Ra-226 and its progeny will eventually represent a more significant portion of the inventories due to its relatively long half-life. As a result, detection limit requirements for Ra-226 are often quite low. Ra-226 is an alpha emitter with weak gamma emissions. The required Ra-226 detection limit requirement can be 8 or more orders of magnitude lower than the activities of shorter-lived radioisotopes commonly present in various SRS sample matrices. Therefore, a very efficient separation of Ra-226 from high levels of interfering radionuclides is required. High sample radiological doses require initial radiochemistry to be conducted in SRNL's remote handled shielded cells facility. The separations are then completed in radiological hoods. A series of delayed gamma analyses are conducted for Ra-226 and for the Ra-224 tracer's progeny. Details of the Ra-226 analysis method development and implementation in these high activity matrices will be discussed.


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Log 504. NATIONAL TECHNICAL NUCLEAR FORENSICS (NTNF): HISTORY AND APPROACH OF THE UNITED STATES NTNF MISSION. Morrison, J.J. (1), Zeitoun, A. (1), Freeman, J.R. (1, 2). (1) United States Department of Homeland Security, Countering Weapons of Mass Destruction Office. (2) Belcan Government Services. In the event of a nuclear detonation in the United States, interdiction of a nuclear device, or seizure of nuclear or other radiological materials, there will be tremendous pressure to attribute the source, establish responsibility, and ensure the prevention of a subsequent incident. Along with intelligence and law enforcement investigations, nuclear forensics stands as one of the three pillars supporting attribution. Nuclear forensics is the collection, analysis, and evaluation of pre-detonation (intact) and post-detonation (exploded) radiological or nuclear materials, devices, and debris, as well as the immediate effects created by a nuclear detonation. The U.S. response to any attack will have to be backed up by demonstrable proof and nuclear forensics contributes to this by helping to identify the type of weapon and nuclear material used and where it came from. The United States National Technical Nuclear Forensics (NTNF) interagency partners, which include the Departments of Homeland Security, Defense, Energy, Justice, and State and the Office of the Director of National Intelligence, ensure the nation's readiness to execute this mission. The Interagency is consistently focused on improving its capabilities by sustaining a workforce of educated and trained scientists and continually assessing and enhancing the accuracy, precision, and timeliness of nuclear forensics conclusions, ensuring the nation's readiness to execute this national security mission. An effective nuclear forensics and attribution capability counters illicit trafficking in nuclear materials, deters nuclear terrorism, and promotes global nuclear security. Log 505. PHOTONUCLEAR PRODUCTION AND RAPID SEPARATION OF CARRIER FREE 185W ISOTOPE TRACER SOLUTIONS. Snow, M.S. (1); Kinlaw, M. (1); Ward, J.L. (1); Rynes, A. (1). (1) Idaho National Laboratory. Tungsten (W) concentration and isotopic analyses form a critical component of many terrestrial and cosmogenic sample analyses, the ease and measurement precision of which can be greatly facilitated through the addition of an enriched tungsten isotope solution for chemical yield tracing. In this work, we report a method for production and chemical purification of carrier free W-185 using photonuclear reactions followed by rapid chemical separations. Carrier free W-185 is produced through bremsstrahlung irradiation of a natural W target using an electron linear accelerator to produce Ta-185 via W-185(g,p) reaction; following production, the W target material is rapidly dissolved and Ta-185 is isolated from the bulk W matrix via a specialized low pressure chromatographic system. Following isolation, Ta-185 (t1/2 = 49 min) decays to produce high purity W-185. Results optimizing the production, target dissolution, and rapid separation of Ta from bulk W target material for carrier free W-185 isotope solutions will be presented. Log 506. DEVELOPING FRAM Pu-242 ABUNDANCE CORRELATION EQUATION FOR NOMINALLY WEAPONS GRADE Pu. Rim, J.H. (1); Porterfield, D.R. (1); Yoho, M.D. (1, 2); Tandon, L. (1). (1) Los Alamos National Laboratory. (2) University of Texas at Austin. Plutonium samples are routinely analyzed using non-destructive gamma-ray analysis for plutonium isotopic abundance and Am-241 and Np-237 concentration. One limitation of this method is in measuring Pu-242 isotopic abundance. Pu-242 has gamma emission characteristics that don't allow its isotopic abundance to be readily determined in a given sample spectra. Many gamma-ray analysis codes used for plutonium isotopic abundance measurements utilize a correlation relationship using the other plutonium isotope abundances to estimate the Pu-242 isotopic abundance. For the Los Alamos National Laboratory (LANL) developed Fixed-Energy, Response Function Analysis with Multiple Efficiency (FRAM) code, this correlation equation was developed based on analyzing a large number of plutonium spectra of varying Pu-240 enrichments and has a limitation in accurately estimating Pu-242 content in nominally weapons grade plutonium (< 7% Pu-240). This presentation will discuss the use of U.S. DOE NBL CRM 126A for developing a more accurate correlation equation for nominally weapons grade plutonium samples for FRAM version 5.2. The accuracy of the new correlation equation was further tested using samples from the LANL Pu metal exchange with similar isotopic abundances. This document had been reviewed and assigned publication number: LA-UR-17-31297


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Log 507. RADIOCHEMISTRY AT COLORADO STATE UNIVERSITY. Sudowe, R. (1). (1) Colorado State University. Radiochemistry has a long tradition at Colorado State University going back to the first classes in radiochemistry and radiation chemistry taught in 1964. In 2002, Radiochemistry was established by Dr. Ibrahim as its own formal specialty within the Radiation Protection and Measurements Section in the Department of Environmental & Radiological Health Sciences. In the past CSU's radiochemistry faculty and students have participated in a variety of research efforts, such as the monitoring of fallout from nuclear weapons testing in soil, water, plants and animals and the radiochemical analysis of mill tailings and effluents associated with uranium mining. One of the largest and most interesting radiochemistry projects initiated by CSU was the determination of off-site plutonium concentrations in soils from the Rocky Flats site. Current radiochemistry research efforts focus on environmental monitoring, nuclear forensics, emergency response as well as the nuclear fuel cycle. In addition, faculty and students from CSU have been collaborating very closely with scientists from the Institute for Environmental Radioactivity at Fukushima University to study the environmental impact of the Fukushima nuclear accident. This presentation will provide an overview of the Radiochemistry Program at Colorado State University and its laboratory facilities. It will also give examples of current research areas. Log 508. RADIOLOGICAL FORENSIC ANALYSES OF 137Cs AND AmBe SEALED SOURCES. Snow, M.S. (1); Finck, M.R. (1); Carney, K.P. (1). (1) Idaho National Laboratory. The wide usage of 137Cs and AmBe radiological sealed sources by the medical and industrial communities has caused concern that these sources might be employed by terrorists in a radiological dispersal device. Nuclear forensic analyses of radiological sources may provide law enforcement officials key information on the age and provenance of these sources, thereby assisting in material attribution. The isotopic composition of radiological materials represents an important signature, however accurate determination of the isotopic composition and usage of this information for applications such as material age dating requires rigorous chemical separations followed by radiochemical/mass spectrometric analysis techniques. This talk provides an overview of many of the signatures and challenges confronting nuclear forensic analyses of 137Cs and AmBe sources. Various age dating methodologies and the unique information each parent-daughter isotopic system provides will be presented. New chemical separation methods for improving 137Cs-137Ba age dating, along with the advantages and disadvantages of each approach, will also be presented. Finally, specific examples from case study analyses of 137Cs and AmBe sealed sources performed at Idaho National Laboratory will be provided.


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Log 509. CHALLENGES AND OPPORTUNITIES IN CHARACTERIZING NONTRADITIONAL NUCLEAR MATERIALS. Tandon, L. (1); Schake, A.R. (1), Olson, A.C. (1), Rim, J.H. (1); Kuhn, K. J. (1). (1) Los Alamos National Laboratory. In a facility handling nuclear materials to support international safeguards, product manufacturing, nuclear security, and environmental compliance missions, requirements to support these missions typically include measurements of fundamental attributes - such as actinide assay or isotopic composition - with a high degree of confidence and traceability to metrology standards. Attribute measurements are generally performed to: 1) meet specifications for a manufactured product, 2) meet regulatory requirements, or 3) track material within a plant or facility. Unique challenges are presented if these materials are nontraditional in terms of chemical form, such as plutonium tetrafluoride or plutonium-beryllium compounds. Further, the recovery of nontraditional nuclear materials for processing or analysis may be complicated by encapsulation such as cladded nuclear fuel and coated foils that require sample characterization merely to plan and execute material extraction. Upon material extraction, problems also often arise with undefined protocols in order to completely solubilize samples for destructive analysis without losing or introducing matrix constituents. For dissolved plutonium compounds or uranium fuels, existing chemical separations (ion-exchange or solvent extraction) scheme may require modification or further development work is necessary to provide high quality results. This presentation will discuss fuels and other materials that are prevalent globally but have few recent publications describing how to characterize these materials by destructive analytical techniques. This paper will highlight advances in actinide analytical chemistry of special nuclear materials. This document had been reviewed and assigned publication number: LA-UR-17-31257 Log 510. A NEW CONCEPT OF AN EFFECTIVE DETECTION DISTANCE IN GAMMA-RAY MEASUREMENT. Byun, J.I. (1). (1) Korea Institute of Nuclear Safety. The gamma-ray interactions with detector materials are characterized by mainly photoelectric absorption, Compton scattering and Pair-production effects. The detection efficiency of a detector for gamma-ray sources depends on the geometry and chemical compositions of a detector and gamma-ray source, gamma-ray energy and source-to-detector distance. For these reasons, scaling the detection efficiency may be complex analysis. In order to simplify the geometrical considerations in calculating the efficiency, semi-empirical method, using an effective interaction depth with a virtual point detector concept(hereafter referred to as "VPD") that can be regarded as a fictitious point placed on the symmetry axis of the detector, was suggested by several researchers. The detection efficiency can be simply determined using the VPD concept without detail detector's geometric information because the detector can be regarded as a point detector. For this reason, the concept has been applied to the correction for self-absorption or cascade coincidence summing effects. The characteristics of the VPD concept have been also studied by several researchers. This study aims 1) to interpret more systematically the VPD concept, 2) to expand the VPD concept to a new concept of effective detection distance by introducing a virtual point source concept and 3) to characterize the effective detection distance for a high purity germanium detector and gamma-ray sources. The virtual point detector concept was expanded to a new concept of an effective detection distance by introducing a virtual point source concept. The effective detection distance was characterized through the mathematical interpretations and Monte Carlo simulation for the varied source-to-detector distances, gamma-ray energies and gamma-ray source's geometries. Through the characterization, it was found that the detection efficiency can be defined as the function of the effective detection distance for the different energy. It is expected for the concept to apply to the determination of the geometric efficiency for gamma-ray sources with unknown geometry as the non-destructive gamma-ray spectrometry Log 512. ANALYSIS OF ULTRA-TRACE IMPURITIES IN TEFLON REFLECTOR FOR SENSITIVE SCINTILLATOR BY USING ACID EXTRACTION FOLLOWED BY NAA. Sun, G.M. (1); Lee, K.M. (1). (1) Korea Atomic Energy Research Institute. A Teflon, PTFE is the polymerized form of tetrafluoroethylene and has been proved to be the best choice for the reflector of scintillator. The reflection coefficient of Teflon is about 0.99, slightly better than other reflector materials like Lumirror, ESR film, Tyvek paper and TiO paint. Teflon has many unique properties, which make it valuable in radiation measuring applications. However, the ultra-trace impurities including


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metal elements and uranium and thorium make it challenging to distinguish the critical weak signals from their interfering backgrounds. An acid extraction method followed by INAA was applied to enhance the detection limit. Metallic impurities in a commercially available PTFE sample are Al, Cr, Fe, Ni and Cu, whose impurities levels are about several ng/g to .g/g. The typical value of U and Th are several ng/g. Log 513. VISUALIZATION OF 14CO2 GAS FIXATION BY PLANTS. Nakanishi, T.M. (1); Sugita, R. (1); Kobayashi, N.I. (1); Tanoi, K. (1). (1) The University of Toky.o Carbon constituting the plant tissue is derived from the fixation of the carbon dioxide in air by photosynthesis. However, how carbon is fixed and forming the new tissue is not known in detail. For example, we found that the route to transfer the photosynthates is different among the tissues, suggesting that they are not translocating according to the simple rule, from source to sink. To visualize carbon fixation manner by plants, 14CO2 gas was prepared by mixing 14C labeled sodium hydrogen carbonate with 2-hydroxypropanoic acid. Then the emitted 14CO2 gas was introduced to a plastic bag covering the portion of the plant tissue. A rice and a soybean plant were fixed on the scintillator deposited with FOS (fiber optic plated) and the beta-ray emitted form 14C was introduced to a highly sensitive CCD camera. In the case of a soybean plant, when the 14CO2 gas was supplied from the stem, the photosynthates moved both ways, to the meristems of the upper part and the root tip, whereas the accumulation of the photosynthates in the first leaves was not dominant. When the gas was introduced the bag sealing only the first leaves, the fixation in the leaves was very fast. In the case of a rice plant, the photosynthates movement was analyzed when the gas was introduced to the specific leaf and compared the assimilation manner under Mg deficiency. Log 514. EXPERIMENTAL TEST BED TO INVESTIGATE RADIONUCLIDE TRANSPORT. Bowen, J.M. (1); Covert, M.A. (1); Huggett, N.L. (1); Carman, A.J. (1). (1) Pacific Northwest National Laboratory. PNNL is recognized as a world leader in nuclear explosion monitoring science. PNNL pioneered remote, automated noble gas collection and measurement. However, there could be potential in fission products we normally think of as immobile, refractory elements or more volatile elements immobilized by a solid matrix. If these interact with the matrix while hot to form mobile species, there could be new avenues for explosion or nuclear accident monitoring. We have developed a laboratory test bed to identify and predict radionuclides that may form mobile complexes through interactions with different geologic media. Experiments being conducted using this test bed will help characterize the mobility of such compounds and, potentially, infer knowledge about compounds generated that are only stable at higher temperatures and pressures. Parameters being tested include geologic matrix effects, temperature, moisture content, and organic content. This presentation will cover design features and preliminary results. PNNL-SA-131348


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Log 516. GEOCHEMISTRY OF RESISTATES - THE LAST WORD? Inn, K.G.W. (1). (1) K&E Inn Ovations Inc., University of Hawaii/Manoa. Milli-fraction acid-resistant U and Th-bearing minerals are widespread across the US. The bonding of highly charged mid-size cations with Si+4 tetrahedron anions provide the most chemical resistant climate against HF/HNO3 attack as pointed out in the geochemical Bowen Reaction Series and Goldich Weathering Series. A search through over 3700 minerals in the Webmineral database yields a limits number of radioactivity bearing nesosilicate [10], sorosilicate [10], inosilicate [1], cyclosilicate [2], and phyllosilicate [1] minerals. Zircon and thorite are the likely bad actors, but a few other identified silicate minerals may also contribute to the problem of incomplete acid dissolution and therefore non-equilibration with radiochemical tracers. Since quantitative results require TOTAL dissolution of sample & equilibration with tracers, it is suggested to carefully define the question to be answered and conduct trial dissolution/fuse to find out if there is a problem before radiochemical production begins. This study is suggestive, but more dissolution trials on suspect minerals are needed on the identified minerals and as yet unevaluated classes of minerals harboring radionuclides. Is the Leach/total dissolution/fusion question settled? For me the answer is "YES! - don't guess, get data, make smart dissolution choice. Sample dissolution throughput is the radiochemistry bottleneck, and bridging to rapid purification steps is not always smooth. So, new approaches/research effort is very much needed! The new work will have tremendous impacts on turnaround times and reliability for emergency response, forensics, radiobioassay, environmental, and commercial measurements. Log 517. TRANSFER OF RADIOCESIUM SUPPLIED TO THE UPPER PART OF A RICE PLANT AT DIFFERENT GROWTH STAGES. Ohmae, Y. (1); Nihei, N. (1); Hirose, A. (1); Kobayashi N.I. (1); Tanoi, K. (1); Takata, D. (2); Nakanishi T.M. (1). (1) Graduate School of Agricultural and Life Science, The University of Tokyo. (2) Preparatory Office for Faculty of Agriculture, University of Fukushima. Plants may uptake radiocesium not only from contaminated soil and water via their roots, but also from contaminated soil and other floating matter in the air which gets wind-blown onto the surface of leaves and stems. However, little is known about plant Cs uptake from suspended matter in the air. In this research, the effect of radiocesium absorbed from the upper part of a rice plant and its accumulation in the grain was investigated. Cesium-137 contaminated water was sprayed onto leaves and husks of rice plants at different growth stages, namely, before ear emergence (BEE), flowering (F), and grain filling (GF). After grain filling, the grain was harvested concurrently, and husks were removed. Because flowering date of each husk differed up to a week, grains were then subdivided into four maturation stages according to their size and color. Cesium-137 concentration in each sample was determined using the germanium semiconductor detector. Cesium-137 content in grains obtained from plant representing BEE, F and GF stages were 5, 109, and 106 Bq/kg, respectively. At BEE stage, an unclear relationship was observed between maturation and Cs-137 concentration. At F stage, Cs-137 concentrations in grains increased with maturation, however, at GF stage, Cs-137 concentrations in grains decreased with maturation. This study shows that brown rice can easily absorb Cs-137 at the beginning of grain filling.


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Log 518. THE CONCENTRATION FACTORS OF MARINE ORGANISMS AND THE DISTRIBUTION COEFFICIENTS OF SEDIMENT. Choi, S.W. (1); Kim, D.J. (1);Chae, J.S. (1). (1) KINS. The concentrations factor of 14 heavy metals in marine organisms at the neighbouring sea of Korea were measured and investigated, respectively. The 359 seawater samples, 332 fish samples, 20 Cephalopods and 22 Crustaceans, 15 Molluscs, 38 Macroalgae were measured the concentrations of heavy metals. The concentration factors in 314, 22 sampling locations were analyzed in concentration of seawater and marine organisms, and in that of seawater and sediment, respectively. The concentrations in seawater were Sr(7,030 ug kg-1), Rb(106 ug kg-1), Fe(13.6 ug kg-1), and Cs(2.08 ug kg-1), respectively. The concentrations of muscle of marine organism were Sr(56.1 mg kg-1), Fe(23.0 mg kg-1), Zn(9.12 mg kg-1), Cs(5.64 mg kg-1), and Mn(1.88 mg kg-1), respectively. The concentration factors in all of organism were highest in P, Mn, Cs, Fe and lowest in Na, Sr, Rb, Mo. The concentration factors of muscle in fishes showed strikingly high P(383,000), Mn(42,700), Cs(25,000) and Sr(3.06), respectively. Highest concentration factors of P(286,000), Cu(169,000), Mn(111,000), and Sr(10.1) were measured in Molluscs, respectively. The concentration factors of macroalgae showed P(127,000), Mn (64,800), Cs(25,500), and Sr(15.1). The results indicated that the concentration factors of 14 heavy metals in the Echinoderms, Molluscs were higher than that in the fish and cephalopods except for Mo, Ba. The concentrations of sea sediment were Fe(32,700 mg kg-1), Mn(705 mg kg-1), Sr(467 mg kg-1), and Cs(0.889 mg kg-1), respectively. The sediment distribution coefficients showed Fe (88,600,000), Mn(8,020,000), Cs(4,560), and Sr(71.2) , respectively. The mean concentration factors and the sediment distribution coefficients of the heavy metal were similar to the recommended value from IAEA (2004) and IAEA (2010). Log 519. COMPOUND SPECIFIC RADIOCARBON ANALYSIS FROM INDOOR AND OUTDOOR AIR SAMPLES VIA ACCELERATOR MASS SPECTROMETRY. Kretschmer, W. (1); Schindler, M. (1). (1) University of Erlangen. Many volatile organic environmental compounds are potentially dangerous due to their allergic or carcinogen impact on humans. For the establishment of effective countermeasures for lowering their concentration in houses, sources have to be known. Our investigation is focused on aldehyde compounds since their indoor concentration is often above the official guidelines and since they originate from biogenic or anthropogenic sources. Both types of sources can be distinguished by their different 14C content which can be measured via accelerator mass spectrometry (AMS). For the collection and separation of these gaseous substances they have to be converted into liquid or solid phase by derivatization. This leads to the incorporation of up to six additional carbon atoms into the derivatized sample and hence to a reduced 14C content. To reduce the number of additional carbon atoms and to optimize efficiency and duration of the procedure, different derivatization compounds and methods have been tested with acet- and formaldehyde of known 14C content.The Erlangen AMS facility, based on an EN tandem accelerator and a hybrid sputter ion source for solid and gaseous samples, is well suited for the measurement of isotope ratios 14C/12C ≈ 10-12 – 10-15. The 14C concentration of the calibration samples and from indoor air samples in apartments, beer taverns and schools have been determined by AMS, the corresponding results are discussed with regard to potential sources of aldehydes. Finally first outdoor air samples from different locations have been analyzed to investigate the influence of traffic on their 14C content.


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Log 520. MONTE CARLO STUDY OF 3D STRAY RADIATION DURING INTERVENTIONAL PROCEDURES. Alfuraih, A. (1); Alzimami, K. (1); Kadri, O.(1). (1) King Saud University. Besides patient exposure to primary beam, the ultimate need to study the operator exposure to scattered radiation, during interventional medical procedures, is obvious. The purpose of this work is to investigate the 3D stray radiation distribution during realistic interventional scenario, using the Geant4 (version 10.3) code. We used the computational phantom, i.e. HDRK-Man and the GE Infinia 3/8" C-arm machine. The effect of the kVp and the field of view (FoV) parameters, on the spatial scattered particles was studied. The absorbed dose distribution, for an operation room (4X6X3 m3), for X-Ray tube outputs of 60kVp (2.3mm Al), 80kVp (3.2mm Al) and 120kVp (4.3mm Al) and 15, 20, 25 and 30 cm FoV, were calculated for 34 plan levels. We analyzed plan levels corresponding to Eye lens, Lung and Prostate radiosensitive organs. The comparison of the stray radiation per level, show that the variation effect of the FoV was less than 5% for the upper half space of the room (around the imager detector) and reach 65% for the lower area, for each fixed kVp. Moreover, for fixed FoV, the results show a relative difference range 0-24%, 1-36% and 1-65% when passing from 120 to 80kVp, from 80 to 60kVp and from 120 to 60kVp, respectively. Thus, a special care should be taken into account for the operator exposure optimization more seriously when changing the kVp than the FoV parameters. Moreover, we can use the larger FoV, if needed, but staying in the safe side of the patient exposure limitations. Log 521. EVALUATING NON-CONVENTIONAL MATERIALS FOR PURIFICATION OF ISOTOPES FROM TARGETS AND BLIP COOLING WATER. Fitzsimmons, J. (1); Torre, B. (2); Hubbard, K.(3); Foley, B.(4); Copping, R.(5); Medvedev, D.(1); Younes, A.(1); Cutler, C.S.(1); Mausner, L. (1). (1) Brookhaven National Laboratory. (2) University at Buffalo. (3) Napa Valley College. (4) Fairmont State University. (5) Oak Ridge National Laboratory . Non-conventional materials such as titanium based ion exchangers and SynPhase Lanterns were evaluated for purification of various isotopes from target simulated solutions or from BLIP cooling water. SynPhase Lanterns were used to examine the separation of Ac-225 from bulk thorium and fission products in 1 M citric acid at pH 2. The sulfonic acid functionalized SynPhase Lantern was found to have high specificity for Actinium-225 (Ac-225) and Lanthanum (La) over Thorium, but they could not be used to separate Ac-225/La from other metals. This information was compared to studies performed with a cation exchange resin under the same conditions. The SynPhase Lanterns were also used to evaluate the potential speciation of the retained La and Rh species from a solution of 1 M citric acid at pH 2. La was used as a surrogate for Ac-225. Various functionalized SynPhase Lanterns were evaluated for their ability to capture Vanadium-48, Stronium-82 and Berylium-7 from BLIP cooling water and the captured isotopes were purified with either titanium based ion exchangers or other resins. Kd values for sodium titanium silicate ion exchange material was determined for over 40 metals from sodium acetate at pH 1-5. Log 522. DEFINING ISOTOPE PROCESSING WINDOWS BY UNDERSTANDING ANALYTICAL DATA AND IMPURITIES ASSOCIATED WITH ACCELERATOR PRODUCED ISOTOPES AT BROOKHAVEN LINAC ISOTOPE PRODUCER. Fitzsimmons, J. (1); Medvedev, D. (1); Younes, A. (1); Cutler, C.S. (1); Mausner, L. (1). (1) Brookhaven National Laboratory. During the production and purification of medical isotopes the desired radiopurity should be > 99%. Many isotopes have to be purified at specific times in order to minimize radioimpurities and achieve the desired radiopurity, and this could be called the 'isotopes processing windows'. Gamma spectroscopy and/or isotope production codes such as MCNPX can be used to determine processing windows for a desired radioisotope. For some radioactive isotopes, such as Stronium-82 the time after bombardment of a critical purification step can dictate the level of radiopurity. The processing window for Sr-82 and the quantification of radioactive Rb impurities in purified Sr-82 will be discussed. During the proton irradiation of Thorium to produce Actinium-225, over 400 fission products are co-produced and isotopes of interest such as Rh-105 (directly or via decay of Ru-105), At-211, and Ag-111 could be purified and made available to the research community. Other radioisotopes coproduced that influence the 'processing window' or make achieving 99% radiopurity problematic are: Ac-226 and Ac-227 for Ac-225, Ag-112 (daughter from Pd-112) and Ag-105 for Ag-111; Rh-100, Rh-99, Rh-102 and Rh-101 for Rh-105; At-210, At-209 and At-216(a decay chain) for At-211; and


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Ru-103, Ru-97, Ru-106 for Ru-105 (production of Rh-105). Potential processing windows for the different isotopes will be discussed. The benefits and drawbacks of using an ICP-OES versus using an ICP-MS for the analysis of Sr-82 and the validation of ICP-OES and gamma spectroscopy systems will be discussed. Log 523. RAPID DETERMINATION OF STRONTIUM-90 IN ENVIRONMENTAL SAMPLES BY THERMAL IONOZATION MASS SPECTROMETRY. Kavasi, N. (1), Sahoo, S.K. (1). (1) National Institutes for Quantum and Radiological Science and Technology (QST), Japan. After the Fukushima accident, rapid and reliable determination of Sr-90 in environmental samples became an important task since Sr can substitute Ca in human body causing long term radiation burden. Measurement of 90Sr can be speed up using mass spectrometry instruments compared to radiometric quantification, however the isobaric interference from Zr-90 and peak tailing on the higher side from Sr-88 can make problematic the ion beam detection of Sr-88.Thermal ionization mass spectrometry is one of the most reliable techniques for high precision and accurate measurement of Sr isotopic ratio, however successful application for Sr-90 determination in environmental samples has not been reported. In this work, a new Sr-90 analysis method was implemented using Isotopx Limited, Phoenix X62 Thermal Ionization Mass Spectrometer (TIMS). Standard Sr solution (NIST-987) containing a known concentration of 90Sr were used for 90Sr/88Sr isotopic ratio determination gravimetrically. Abundance sensitivity for 90Sr/88Sr ratio was 2.32e-10. This method is very sensitive for Sr-90 detection and detection limit is about 1 mBk (0.2 fg) and has been measured using Daly ion counting system in combination with Faraday cup detectors. During the Sr-90 measurement, Zr-90 isobaric interference was reduced due to Re ribbon ionization potential and chemical separation with extraction chromatography resins (Sr resin). Analytical method of validation was established with wild berry (IRMM-426) and lake sediment (NIST-4354) certified reference materials. Log 524. PERFORMANCE OF COSMIC GUARD AND SAGE WELL DETECTOR FOR ENVIRONMENTAL RADIOLOGICAL ANALYSIS. Ilie, G. (1); Persson, H. (1); Phillips, K. (1). (1) Mirion Technologies (Canberra), Inc. Gamma spectrometry laboratories often analyze environmental samples with low radionuclide content. The determination of low level activities of radionuclides by gamma-spectrometry is challenged by high background which can mask the signal from a sample or increases the uncertainty of peaks that are found. There are several sources which can produce background in gamma ray spectrometry. A primary contributor to the gamma-ray background is terrestrial radiation resulting from naturally occurring radiological materials (NORM). The background induced from NORM can be considerably reduced by shielding. Another source of background is caused by highly penetrating cosmic rays passing through the shielding and interacting with the detector which produces a characteristic continuum response in a spectral histogram. Reducing background induced by these latter two components typically requires active systems to veto these unwanted events. Mirion Technologies (Canberra) Inc. has recently introduced a cosmic veto system that allows users to readily mount on a shielded HPGe systems in order to gain the benefits of cosmic background reduction. The CosmicGuard system leverage modern digital signal processing, which allows users to easily configure and operate the system. This digital system acquires not only the vetoed spectra, but also the unsuppressed data, which allows for quality assurance and defendable results. The performance of the SAGe Well detector within a shield in conjunction with the CosmicGuard system has been evaluated for a range of sample sizes and geometries counted inside the well, on the endcap, and in different beakers. The performance of the system will be presented.


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Log 525. SPECTROSCOPIC TECHNIQUES FOR THE CHARACTERIZATION OF DENDRIMER COMPLEXES FOR NUCLEAR WASTE REMEDIATION. Thomas, K.E. (1); Fishman, D.A. (1); Nilsson, M. (1). (1) University of California, Irvine. The generation of used nuclear fuel (UNF) has been a strong deterrent in widespread acceptance of nuclear energy. Separating the constituent elements and removing the minor actinides for transmutation can significantly reduce the radiotoxicity and decay heat of UNF. Though different processes have been proposed, efficient, highly selective, and scalable methods to separate the minor actinides from lanthanides, and from each other, remains a formidable challenge for achieving a closed fuel cycle due to their chemical similarities. Polyamino polycarboxylic acids, such as diethylenetriaminepentaacetic acid (DTPA), have been proposed as ligands to improve lanthanide/actinide separation by holding actinides as complexes in the aqueous phase while lanthanides are extracted into an organic phase. Polyamidoamide (PAMAM) dendrimers strongly resemble hyperbranched forms of these polyamino polycarboxylic acids, with the potential for high metal ion loading and selectivity, ultimately enhancing separation factors and minimizing overall waste from solvent extraction steps. Ultraviolet-visible spectroscopy, fluorescence spectroscopy, and electron paramagnetic resonance spectroscopy have been performed on PAMAM dendrimer complexes with uranium and lanthanides. The results presented constitute preliminary investigations on metal ion loading capacity, metal/dendrimer stoichiometry, and geometry and symmetry of dendrimer-metal complexes. Formation constants are calculated for four generations (G0-G3) of dendrimer complexes with uranium and lanthanides to examine relative strength among the generations as a metric of potential holdback strength. Log 526. EDUCATION IN HEALTH PHYSICS AT MILANO UNIVERSITY. Groppi, F. (1); Manenti S. (1); Bazzocchi A. (1, 2). (1) University degli Studi di Milano & INFN, L.A.S.A. Laboratory. (2) ITIS Mattei San Donato Milanese, Italy. At the University of Milano, Physics Department is active for the Master Degree the didactic line in Health Physics related to themes and research that have as their common interest the ionizing radiation in its biomedical, environmental and nanotoxicological applications The relevant courses are Health Physics and Laboratory of Health Physics that are related to the fundamental concepts of the natural and artificial radioactivity, as well as the detectors for measurement, the applications of radiations, the dosimetric and radioprotection aspects. On this basis in the Laboratory classes the students are trained on the different techniques for measuring different type of radiations. One theme is the measure of Rn-222 with different kind of detectors selected as a function of the type of information to be obtained. We will present our laboratories, the instrumentation that the students have available for these types of measures and some of the results that they obtained. Parallel we started up a project devoted to students of Italian High Schools to make them more trusted about scientific culture and in particular to radioactivity theme that is in general misled because it is almost unknown: this concept is linked to nuclear arms and its usage in uncorrected way to produce energy in the Nuclear Power Plans. The nuclear power's association with nuclear weapons has contributed to its lack of acceptance in particular in Italy, where the "nuclear issue" is a taboo since a long time. We will present the main goals and some results of the project.


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Log 527. CHARACTERIZATION OF HOT PARTICLES IN AIR FILTERS COLLECTED IN FINLAND AFTER THE CHERNOBYL ACCIDENT. Groppi, F. (1); Ioannidou, A. (2); Paateroc, J. (3). (1) University degli Studi di Milano & INFN, L.A.S.A. Laboratory, Italy. (2) Aristotle University of Thessaloniki, Physics Department, Greece. (3) Finnish Meteorological Institute, Observation Services, Finland. Following the accident at the Chernobyl nuclear power plant on 26 April 1986, about 2 . 1018 Bq of condensable radioactive materials were released, the majority of which was deposited in Europe. Most of the released radioactive material was in particulate form, whereas noble gases and most of iodine were in gaseous form. Sometimes their activities may be so high that even a single particle may cause a severe health hazard. Radioactive particles released from Chernobyl have been described by many as 'hot particles' where 'hot' is synonymous with 'highly radioactive'. In the Chernobyl accident most of the particulate material was deposited within 20 km of the plant, but about one-third was transported even thousands of kilometres. Air masses originating from Chernobyl on 26 April 1986 arrived in Finland very early after the accident. Identification of the hot particles in filters collected in Helsinki Finland between 27-29 April 1986 was done by autoradioagraphy technique (Cyclone Plus of PerkinElmer) in the University of Milano, Italy. Morphology and elemental information for particle characterization will be given by SEM analysis. Elemental distribution and structure information will be given by µ-XRF analysis. Log 528. NOVEL DETECTION OF 36Cl IN HALITE BY SECONDARY ION MASS SPECTROMETRY. Zimmer, M.M. (1); Wacker, J.F. (1); Bowen, J.M. (1). (1) Pacific Northwest National Laboratory. Chlorine-36 is a cosmogenic nuclide present in abundances of 1·10-13 relative to stable Cl. When natural Cl is irradiated, the 36Cl abundance increases due to activation of 35Cl. Nuclear activity has resulted in elevated 36Cl in seawater, groundwater, ice cores, and soil, and the signal may persist for extended periods due to a long half-life of ~3·105. Traditional analysis of 36Cl is done by accelerator mass spectrometry (AMS) because of dilution of the 36Cl signal in the environment. However, particulate material collected near a nuclear site may contain enough 36Cl to be measured by novel techniques such as secondary ion mass spectrometry (SIMS). We have calculated that 36Cl measurements are feasible in halite (NaCl) using PNNL's CAMECA ims 1280-HR. A recent irradiation of pure halite will provide the necessary materials to develop the method to measure stable and activated Cl isotopes. We will present the method development and results for the analysis of 35Cl, 36Cl, and 37Cl in irradiated halite. Calculations are also ongoing to determine how far radiation will penetrate into halite and other Cl-bearing evaporite minerals to constrain how much 36Cl could potentially be produced, and therefore how readily a 36Cl signature could be obtained using this novel approach.


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Log 529. EXPERIMENTAL EXCITATION FUNCTIONS FOR Zr-89 PRODUCED BY DEUTERON BEAMS. Manenti, S. (1); Groppi, F. (1). (1) Università degli Studi di Milano & INFN, L.A.S.A. Laboratory, Italy. Zirconium-89 is one of the most promising radionuclide in Nuclear Medicine for labelling monoclonal antibodies for bio-distribution studies and for immuno-PET imaging. Furthermore Zr-89-labelled octreotide liposomes can be used for simultaneous PET and magnetic resonance tumor imaging in theranostics applications. Zr-89 (T1/2 = 78.41 h) decays by positron emission (22.3%; .Emax energy = 900 keV) and electron capture (76.6%) to the stable isotope Y-89 %) and has an associated gamma emission at 908.96 kev (I=99.87%) which is the main contribution to the absorbed dose. The longer-lived isotope Zr-88, with a half-life of T1/2 = 83.4 d and a single gamma-ray emission at 392.87 keV is the only one radioisotopic impurity in the Zr-89 production by deuterons beam on Y-89. The Zr-89 radionuclide is produced via the (p,n) nuclear reaction in small medical cyclotrons, bombarding monoisotopic yttrium targets. The experimental excitation functions in this case are measured many times and the data are relatively consistent. We have studied the possibility to produce this radionuclide by deuteron beams, which presents indisputable advantages. A new set of excitation functions for Y-89(d,2n)Zr-89 was measured and compared with the other sets of data present in literature and the results obtained by the simulation of the most common computer codes used in this field. The thin-target yields were fitted with the best mathematical functions and integrated to calculate thick-target yields, to find the optimized couple of irradiation energy and energy loss inside the thick target to maximize the production of the radionuclide. Log 531. THE DEVELOPMENT OF STANDARD REFERENCE CEREALS USING INAA METHOD. Park, H.J. (1); Sun, G.M. (2); Moon, J.H. (2); Lee, O. (3). (1) Kookmin University. (2) KAERI. (3) Youngin University. Information on macro nutrient and trace nutrient can affect the national food and nutrition policies, the national nutrition status, the medical field such as clinical and epidemiology, the food and nutrition academic field. Therefore, it is necessary to develop reliable food for macro- and trace nutrient information and it is important to choose the Standard Reference Materials (SRM). In Korea, nutrient information of cereals and cereals related products is very important because of consuming more than 60% of energy through those foods. To select grain SRM for analysis quality control, dietary consumption by food groups of Koreans was analyzed based on the KNHANES (Phase VI) of 2013-2015. The data was analyzed 16069 people over aged of 19. Additionally, the total grain production of the whole country was examined. From the KNHANES and total grain production data, rice and wheat flour were selected as represent SRM for the grain group. The selected food samples were purchased nationwide in consideration of the production volume and market situation. After purchasing, two homogeneous composite were prepared to contain uniformly distributed dietary material among all analytical subsamples and stable during storage. The final samples were analyzed for mineral such as Se, Mn, Zn, Cu, and Na in two different ways, ICP and neutron activation analysis. In this study, food items for grains were selected for standard reference material based on frequently consuming food based on energy source and production size. And the mineral contents for the materials were cross-checked by two analyses. The results might expedite the development and dissemination of accurate certified reference materials which can be used for precision assessment of food minerals content and a systematic quality control system in nutrient database.


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Log 532. TISSUE FREE WATER TRITIUM AND ORGANICALLY BOUND TRITIUM (OBT) ANALYSIS OF ENVIRONMENTAL SAMPLES USING LIQUID SCINTILLATION COUNTING, ASSOCIATED ANALYTICAL CHALLENGES AND QUALITY ASSURANCE ASPECTS. St-Amant, N. (1); Marsh, R.I. (2); Croudace, I.W. (2), Warwick, P.E. (2). (1) Canadian Nuclear Safety Commission. (2) Raddec International Ltd I GAU-Radioanalytical, University of Southampton, U.K. This study outlines the evaluation of various sample preparation methods for organically bound tritium (OBT) using different types of oxygen chambers. Biota samples including different varieties of fruits, berries, vegetables (beetroot, potatoes and carrot), milk and meat (beef, chicken and fish) were analyzed by the Canadian Nuclear Safety Commission (CNSC) laboratory for both tissue free water tritium and OBT contents. The environmental samples were collected as part of routine regulatory surveillance in the vicinity of Canadian nuclear facilities known to handle H-3. All samples were dehydrated by the freeze-drying method under vacuum, and dry samples were homogenized using a cutting/grinding mill. A range of sample weights were combusted to determine the optimum sample size for combustion for each method. The vacuum recovery of collected combustion water using the different sample preparation methods was also examined. An evaluation of the color and chemical quenching during liquid scintillation counting was conducted to compare the quenching factor for samples prepared by different methods. Finally, the measurement combined uncertainty was determined for samples prepared by different combustion systems. Log 533. EQUILIBRIUM AND KINETIC STUDIES OF LANTHANIDE AND ACTINIDE SORPTION TO ALUMINUM (HYDR)OXIDE MINERALS. Baumer, T. (1); Kay, P. (1); Hixon, A.E. (1). (1) University of Notre Dame. Anthropogenic sources of neptunium, plutonium, and americium have been introduced into the environment through nuclear weapons testing and disposal at legacy waste sites. The long half-lives of these radionuclides mean that once they are released into the environment, they will persist for millions of years. Therefore, it is essential to predict the mobility of these radionuclides in the subsurface environment. We studied europium (as an analog for Am) and neptunium sorption to a suite of aluminum (hydr)oxide minerals – gibbsite, bayerite, corundum, and .-alumina – under equilibrium conditions. Batch experiments and detailed solid-phase characterization (e.g., powder X-ray diffraction, scanning electron microscopy, and infrared spectroscopy) were used to determine the effect of surface acidity on the sorption of europium and neptunium. While the composition of the mineral phase had no apparent effect on europium sorption, preferential sorption of neptunium followed the trend bayerite > corundum > . -alumina. In addition to this gap in basic understanding of equilibrium thermodynamics, the kinetics of europium, neptunium, and plutonium sorption have been largely overlooked. Batch sorption experiments conducted as a function of pH, mineral concentration, and metal concentration were used to determine rate laws for Eu(III) and Np(V) sorption and Pu(V) sorption and reduction in the presence of aluminum (hydr)oxide minerals. In each case, pseudo-first-order expressions were used. Neptunium and plutonium interactions were characterized by a two-step reaction with a fast initial sorption step followed by a slow equilibrium process. Future work is focused on determining sorption mechanisms and developing surface-complexation models to describe these systems.


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Log 534. EFFECTS OF CULTIVAR AND ORIGIN ON THE ELEMENTAL COMPOSITION OF RICE GRAINS. Kato, L.S. (1); Fernandes, E.A.N. (1); Bacchi, M.A. (1); Sarriés, G.A. (2). (1) Nuclear Energy Center for Agriculture, University of Sao Paulo. (2) College of Agriculture Luiz de Queiroz, University of São Paulo, Brazil. As a largely consumed staple food, rice is an important source of carbohydrates and minerals. However, it can also contain toxic elements, mainly As and Cd, at undesirable levels. Brazil is the ninth largest producer of rice, with 70% of the production concentrated in the state of Rio Grande do Sul under the flooded cultivation system. Here, rice grains of four most cultivated Brazilian cultivars called Puitá Inta, Guri Inta, Irga 424 and IRGA 424RI have been analyzed by NAA to evaluate the elemental composition. Twenty-eight samples were collected from eleven producers of certified rice located in different cities of Rio Grande do Sul. The husk of the samples were removed to obtain the brown rice. Analytical portions of 300 mg were irradiated during 4 h and the induced activity was measured with HPGE detectors. Mass fractions of As, Cd, Co, Cs, Fe, K, Mo, Na, Rb and Zn were calculated using the k0 method. Results of As varied from 0.027 ± 0.005 mg/kg to 0.65 ± 0.03 mg/kg. Seven samples were above the maximum limit established by the Brazilian regulation for total As in rice (0.3 mg/kg). Cd results were below the detection limit of 0.25 mg/kg, which was lower than the national regulatory limit of 0.4 mg/kg. Comparing the four cultivars studied, there was no statistical difference for the element mass fractions, with exception of Cs (p<0.05). On the other hand, grouping the samples by producer, there were statistical differences for As, Co, Na, Rb and Zn (p<0.05), indicating influence of origin on the composition of rice. Log 535. TRITIUM SEPARATION FROM PARTS-PER-TRILLION-LEVEL WATER BY A MEMBRANE WITH PROTONATED MANGANESE DIOXIDE. Koyanaka, H. (1); Fukutani, S. (2). (1) Forward Science Laboratory LTD. (2) Kyoto University Research Reactor Institute, Japan. Tritium is a radioactive isotope of hydrogen; almost all tritium in light/heavy water exists as an isomer of water (i.e. HTO, DTO). Separation of the tritium present at low concentrations in water (e.g. several-nano grams per one liter) using conventional methods is fundamentally difficult. However, separation technologies of low concentration tritium are required in various fields, such as fusion plants, effluent treatments, and environmental cleanings. This study introduces a membrane containing protonated manganese dioxide powder that is able to selectively separate tritium from water (e.g. H2O, D2O) at room temperature. For example, the efficiency of tritium removal from light water based on the soaked area of the membrane was 2610000 Bq/m2 h (i.e. 7.3 ng/m2 h) when a test water (150 mL) having 4053 Bq/mL (i.e. 11.4 ng/L) of he initial tritium concentration was used. Moreover, this method enables a continual recovery of enriched HTO as a retrievable final product from the reaction system under normal laboratory conditions. The mechanism of tritium separation might be based on the preferential oxidation of OT- at the interface of water with the protonated manganese dioxide via neutralization of OH-/OD-/OT- with H+/D+/T+. This fundamental method will be tailored for technologies in various fields that require the handling hydrogen isotopes in the near future. Log 536. RADIONUCLIDES IN FRESHLY FALLEN METEORITE KHENEG LJOUAD: A COMPARISON OF EXPERIMENTAL RESULTS WITH MONTE CARLO SIMULATIONS. Povinec, P.P. (1); Breier, R. (1); Ferrière, L. (2); Ková.ik, A. (1,3); Koeberl, C. (2,4); Masarik, J. (1); S.kora, I. (1). (1) Comenius University, Slovakia. (2) Natural History Museum, Austria. (3) MicroStep-MIS s.r.o., Slovakia. (4) University of Vienna, Austria. Low-level concentrations of cosmogenic and primordial radionuclides were analyzed in the recently fallen Kheneg Ljou'd meteorite (fall on 12 July, 2017 in Morocco). The meteorite has been classified as an LL5/6 ordinary chondrite. The measured radionuclide concentrations in the meteorite fragment of 359.78 g (8.5 x 6.5 x 4 cm3) show a wide range of concentrations of Na-22, Al-26, Sc-46, Mn-54, Co-57 and Co-58. The absence of Co-60 indicates that the pre-atmospheric radius of the meteorite was small. This has also been confirmed by Monte Carlo simulations of production rates of investigated radionuclides and their comparison with experimental data. The cosmic-ray exposure age of the meteorite (taking into account the Al-26 half-life of 0.717 Myr) has been estimated to be a few million years. The agreement between the simulated and observed Al-26 activities indicates that the meteoroid was mostly irradiated by a long-term average flux of galactic cosmic rays.


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Log 537. FISSION PRODUCT CHAIN YIELD MEASUREMENTS FROM FISSION SPECTRUM IRRADIATIONS AT NCERC. Bond, E.M. (1); Bredeweg, T.A. (1); Gooden, M.E. (1); Roman, A.R. (1); Rundberg, R.S. (1); Berger, J. (1); Boggs, M. (1); Bowen, S.M. (1); Cisneros, M.R. (1); Gaunt, A.J. (1); Hanson, S.K. (1); Lee, G. (1); May, I. (1); Miller, J.L. (1); Oldham, W.J. (1); Reilly, S.D. (1); Smythe, N. (1); Cox III, D.L. (1); Dry, D.E. (1); Gallegos, M.J. (1); Hudston, L.A. (1); Margiotta, C. (1); Rendon, R.J. (1); Romero, J. (1). (1) Los Alamos National Laboratory. Fission product chain yields were historically determined by chemical separation and beta counting of fissile samples irradiated in carefully controlled fission chamber experiments1;2. These measurements provided the means to extract absolute fission product yields (yield per fission, or Yi/f for the ith fission product) that are included in the international nuclear data libraries, and ultimately used to model and characterize multiplying systems. In this talk we will report on efforts to revitalize this capability to accurately measure fission chain yields in fission chamber experiments using the critical assemblies at the National Criticality Experiments Research Center (NCERC) at the Nevada National Security Site (NNSS). Log 538. A MATRIX METHOD FOR ANALYSIS OF RADIOXENON BETA-GAMMA SPECTRA YIELDING CORRECT DECISION LIMITS. Ringbom, A. (1); Axelsson, A. (1). (1) Swedish Defence Research Agency (FOI). Today, automatic radioxenon systems for detection of nuclear tests are installed worldwide, both within the International Monitoring System for CTBT verification, as well as at national institutions. Many of these systems use a beta-gamma coincidence technique to measure the sample activities. Beta-gamma coincidence data are today analyzed using the so called NCC-method. It has been found, both from measured data and by Monte-Carlo simulations, that this analysis technique result in false detection rates (FDR) exceeding the selected 5% confidence level by as much as 5-10%. It is expected that a new generation of systems will report even higher FDR:s. To address this problem, a new analysis method has been developed, based on a matrix formulation of the analysis problem. This leads to a much simpler analysis procedure, and Monte-Carlo studies show that the calculated critical limit always will be 5%. The analysis method will be presented, together with a comparative study of data from several radioxenon systems. Log 539. RAPID 224Ra MEASUREMENTS IN WATER VIA MULTIPLE RADON DETECTORS. Shibin, Z. (1); Xu, B. (1); Zhang, X. (1); Yu, Z. (1); Burnett, W.C. (2). (1) Ocean University of China. (2) Florida State University Radium-224, with a half-life of 3.66 days, is a powerful tool for oceanographers to discern short timescale (<20 days) water mixing processes in estuaries, coastal waters, and inner shelf seas. It can also be a source of high gross alpha activity in drinking water. We introduce here an improved on-site rapid analysis system for measuring 224Ra in natural waters via 220Rn using multiple radon detectors (RAD7s) in parallel to increase the sensitivity. The short half-life isotope 224Ra is pre-concentrated on manganese-impregnated acrylic fiber (“Mn-fiber”) before measurement of the 220Rn daughter. Before the sample is counted, the water content ratio of the Mn-fiber is adjusted to 1.0 to achieve high and reproducible radon emanation efficiency. A Nafion drying tube (“DRYSTIK”) as well as desiccant is used to lower the humidity and maintain a relatively constant moisture level in the Mn fiber. A typical analysis requires about 2 hours. We tested a 224Ra standard with known activity, and obtained an overall sensitivity of a dual-detector system of 0.050±0.005 (cpm dpm-1). A comparison study showed that natural water samples measured by this method agreed well with an analysis via a Radium Delayed Coincidence Counting System (RaDeCC). The method is recommended for cases where traditional methods are inconvenient, especially for fieldwork in remote areas when electricity and other supplies are not readily available.


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Log 540. ULTRA-SENSITIVE RADIOANALYTICAL TECHNOLOGIES FOR UNDERGROUND PHYSICS EXPERIMENTS. Povinec, P.P. (1); Barabash, A.S. (2); Benedik, L. (3); Breier, R. (1); Dulanská, S. (1); Filosofov, D. (4); Ješkovský, M. (1); Kaizer, J. (1); Kochetov, O. (4); Kontuľ, I. (1); Kameník, J. (5); Kučera, J. (5); Laubenstein, M. (6); Lee, S.-H. (7); Loaiza, P. (8); Nisi, S. (6); Palušová, V. (1); Pánik (1); Piquemal, F. (9, 10); Saakyan, R. (11); Staníček, J. (1); Steier, P. (12); Zeman, J. (1). (1) Comenius University, Slovakia. (2) NRC “Kurchatov Institute”, ITEP, Russia. (3) Josef Stefan Institute, Slovenia. (4) JINR, Russia. (5) Nuclear Physics Institute of CAS, Czech Republic; (6) INFN - Laboratori Nazionali del Gran Sasso, Italy. (7) KORDI, Republic of Korea. (8) LAL, France. (9) Laboratoire Souterrain de Modane, France. (10) Centre Etudes Nucléaires de Bordeaux Gradignan, France. (11) University College London, UK. (12) University of Vienna, Austria. Ultra-sensitive underground gamma-spectrometry, accelerator mass spectrometry, inductively coupled plasma mass spectrometry and neutron activation analysis for the assay of long-lived radionuclides (K-40, U-238 and Th-232) in isotope sources and construction materials designed for underground installations for investigation of rare nuclear processes and decays are discussed. Specific features of each method are compared with the aim to optimize analytical conditions for different types of samples. Detection limits below 1 nBq/g are feasible, depending on the analytical method and sample matrix. Analytical results obtained with various methods for different samples are presented, and limitations of presently available technologies and plans for future developments are discussed. Log 541. MEASUREMENT OF RADIOXENON AND RADIOARGON IN SOIL GAS. Kastlander, J. (1); Aldener, M. (1); Axelsson, A. (1); Fritioff, T. (1); Söderström, C. (1); Ringbom, A. (1); Fritz, B. (2); Hayes, J. (2); Purtschert, R. (3). (1) Swedish Defence Research Agency (FOI), Sweden. (2) Pacific Northwest National Laboratory. (3) University of Bern, Switzerland. The most important indicators for an underground nuclear explosion during an on-site inspection are the radioactive xenon isotopes Xe-131m, Xe-133 and Xe-133m and the radioactive argon isotope Ar-37. In the assessment of a detection of these nuclides it is important to have knowledge about the levels that can be expected due to the natural background. Therefore, it is interesting to simultaneously measure the background levels of radioxenon and radioargon in soil gas, along with other components (i.e. radon, CO2, O2) for a better understanding of the relationship between these constituents. Sub soil sampling has been carried out in the region of Kvarntorp (Sweden), a location with known elevated uranium content in the ground. Almost 40 samples has been taken from ten different sites. The results from analyzing these will be presented. Log 543. POST IRRADIATION EXAMINATION OF U-Mo NUCLEAR FUELS USING NEUTRON COMPUTED TOMOGRAPHY. Abir, M. (1, 2); Craft, A. (2); Williams, W. (2); Rabin, B. (2); Wachs, D. (2). (1) Massachusetts Institute of Technology. (2) Idaho National Laboratory. We demonstrate the use of neutron computed tomography for the non-destructive post-irradiation examination of the radioactive nuclear fuels. Due to potential damage of the radiation detectors from gamma radiation, indirect foil-film transfer technique is used to acquire neutron images instead of digital image acquisition. Poor temporal resolution of the image acquisition technique prohibits acquiring many images for tomography, therefore, limited-angle tomography technique is employed to reconstruct the projection neutron radiographs. Advanced reconstruction algorithm is developed to provide the best possible reconstruction. Furthermore, the reconstructed slices are staked to generate 3D reconstruction and then quantitative analysis is performed. Log 544. ONLINE AND ON-CAMPUS RADIOCHEMISTRY TRAINING AT OREGON STATE UNIVERSITY. Paulenova, A. (1); Higley, K.A. (1). (1) Oregon State University. There are many factors that affect quality of teaching in both modes; however, the online courses have quite different features. The factors most cited include the course design, delivery and content, technology, institutional infrastructure, faculty readiness for online teaching, student readiness for online learning and support. Based on experience at our university, the role of these factors in the radiochemistry training for both the on-campus and e-campus programs is discussed.


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Log 545. CHARACTERISTICS OF PROMPT GAMMA ACTIVATION ANALYSIS FACILITY AT DALAT REACTOR8 . Hai, N.C. (1); Tan, V.H. (2); Dien, N. N. (1); Son, P.N. (1); Anh, T.T. (1), Thang, H.H. (1). (1) Nuclear Research Institute, Viet Nam. (2) Viet Nam Atomic Energy Institute. A prompt gamma activation analysis facility has been developed at the Dalat Nuclear Research Reactor. Thermal neutron beam was received by setting filter combination of silicon, titanium and sulphur in the channel. The parts of the facility consist of collimators, beam stopper, sample holder table, beam catcher, and biological shield. Digital signal processor includes amplifier, ADC and MCA was used to collect and sort the detector signal and the ORTEC Gamma-Vision was used for displaying and analyses of the gamma spectrum. GEM series HPGe-254 cc detector manufactured by ORTEC was used to count the prompt gamma rays (resolution of 1.9 keV at 1332 keV and relative efficiency of 58%). The detection system includes a Compton-suppression spectrometer by using BGO detectors. The characteristics of the facility such as neutron flux, cadmium ratio, gamma background, elemental sensitivities were examined and presented. The absolute efficiency curve of the gamma spectrometer in the range of energy from 121 keV to about 10 MeV was measured and presented. Log 546. RADIOCESIUM CONTAMINATIOIN IN FOREST AND CURRENT SITUATION OF GROWING OAK TREES FOR MUSHROOM LOGS IN FUKUSHIMA. Kobayashi, N.I. (1); Nihei, N. (1); Ito, R. (1); Tanoi, K. (1, 2); Miura, S. (3); Masumori, M. (1); Nakanishi, T.M. (1). (1) The University of Tokyo. (2) PRESTO. (3) FFPRI. The radiocesium contamination in mushroom as well as mushroom logs is a matter of concern in forestry after the nuclear power plant accident in Fukushima. To figure out the contamination situation precisely and make a prospect of mushroom log production, the Cs-137 distribution in 6 fields cultivating oak trees in Tamura city, Fukushima, was investigated in 2015. Then, the Cs-137 concentration in the new branch was found to highly correlate with that in the trunk, which is exactly the mushroom log. This result suggests that the Cs-137 concentration in the trunk could be estimated without felling based on the Cs-137 concentration in the new branch. In addition, trees grown in one of the 6 fields was found to have very low Cs-137 concentration for the Cs-137 concentration in the soil there, possibly because of the characteristic soil property. The impact of the nutritional conditions on the Cs-137 absorption in the oak seedlings grown hydroponically was also investigated by the radiotracer experiment.


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Log 548. INVESTIGATION OF F-ELEMENTS COMPLEXES IN THE HEH[EHP] MIXTURES WITH SELECTED DIGLYCOAMIDES IN N-DODECANE. Paulenova, A. (1); Isaichykava, Y. (1); Gullekson, G. (1); Nyman, M. (1); Brown, M.A. (2); Gelis, A.V. (2). (1) Oregon State University. (2) Argonne National Laboratory. A group extraction of AN(III) and LN(III) from nitric acid with the mixed organic solvent based on a combination of the acidic HEH[EHP] (2-ethylhexyl-phosphonic acid mono-2-ethylhexyl ester) and neutral (either TODGA, N,N,N',N'-tetraoctyl-diglycolamide, or T2EHDGA, N,N,N',N'-tetra(2 ethylhexyl)digly-colamide) ligands was investigated. This system has shown a much better extraction behavior, as well as more efficient Ln/An(III) separations than the previous similar efforts toward mixed extractant system development. Using various spectroscopic methods, we attempted to quantify the ability of extractants to bind f-elements into extractable complexes, including formation of their own inter-molecular adducts and larger aggregates of metal complexes. Stoichiometry of the metal ternary complex species formed in the organic phase under both the extraction and stripping conditions were determined by the slope analysis of distribution ratios and Job's plot methods. Job's plot analysis with Am and Eu radiotracers revealed that their ternary complexes contain 6 molecules of organophosphorus acid and one molecule of DGA. The UV-Vis spectra collected for Nd and Am in the organic phase lend further insight into the nature of metal complexation in the mixed ligand systems: with an increasing concentration of DGA, an increase in the metal coordination number and decrease in the complex symmetry was observed. Investigation of the molecular and supramolecular speciation in organic phase is completed by titration of water, proton and nitrate concentrations and application of NMR and X-ray scattering spectroscopies. Log 549. SECONDARY RADIOCESIUM CONTAMINATION OF AGRICULTURAL PRODUCTS BY SUSPENDED MATTER. Nihei, N. (1); Yoshimura, K. (2); Okumura, T. (3); Tanoi, K. (1); Iijima, K. (2); Kogure, T. (3); Nakanishi, T.M. (1). (1)Graduate School of Agricultural and Life Sciences, The University of Tokyo. (2) Japan Atomic Energy Agency. (3) School of Science, The University of Tokyo. Since the occurrence of the Fukushima Daiichi Nuclear Power Plant accident 6 years ago, decontamination has progressed in Fukushima Prefecture and the former residents are gradually being allowed to return to their homes. However, secondary contamination of agricultural products by suspended matter remains a concern. In the current study, we examined the extent in which agricultural products are been contaminated by suspended matter. The experiment site was located 4.5 km from the Fukushima Daiichi Nuclear Power Plant and had an ambient dose rate of approximately 1.4 µSv/h. Komatsuna (Brassica rapa L.) was cultivated in pots using non-contaminated soil and water, and the pots were arranged 30, 60, and 120 cm above the ground surface. Komatsuna was cultivated on three occasions from July 4th to December 12th, 2017. After harvesting the upper part, half the plants were washed with non-contaminated water and the amount of radiocesium in the plants was measured (after washing); the amount of radiocesium in the remaining plants was measured after harvesting (without washing). The radiocesium concentration in the aboveground parts without washing ranged from 22-333 Bq/kg (dry weight). The radiocesium concentration in the washed plants was predominantly lower than in the un-washed plants. Furthermore, Komatsuna cultivated lower to the ground (30 cm) tended to have a higher radiocesium concentration than plants cultivated at 60 and 120 cm above the ground surface. Therefore, it can be posited that radiocesium detected in Komatsuna leaves was present because of the adhesion of floating matter from the ground surface.


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Log 550. RADIOCHEMICAL STUDY AND MD SIMULATION FOR ENDOHEDRAL FULLERENES. Ohtsuki, Z. (1); Manjanath, A. (2); Ohno, K. (2). (1) Research Reactor Institute, Kyoto University. (2) Department of Physics, Yokohama National University. Endohedral fullerenes which have one or more atoms inside the C60 cage have attracted great current interest. If their mass production becomes possible, they would have many interesting applications such as the stable molecular devices in nano scale or the functionalized materials in body etc. Therefore, in this study, the formation of atom-doped fullerenes has been investigated by using several types of radionuclides produced by several nuclear reactions. From the trace of the radioactivities using a high performance liquid chromatography (HPLC) and a gamma-ray spectrometry, it was found that the formation of endohedral fullerenes (and/or heterofullerene) with small atoms, noble-gas atoms and 4B–6B elements is possible by a recoil process following the nuclear reactions. Furthermore, the possibility of atoms doped fullerenes using Mo/Tc and Au has been newly tested. It is intriguing that these atoms are the elements used in the field of nuclear medicine and further the radioactive fullerenes have potentialities for several biomedical applications including the design of drug for therapy and/or gene delivery. In order to show the possibility of creating endohedral fullerenes by inserting foreign atoms with a suitable kinetic energy into fullerenes, we have carried out large-scale ab initio molecular dynamics simulations on the basis of the all-electron mixed-basis approach by using code TOMBO in which both plane waves (PWs) and numerical atomic orbitals (AOs) are used as a basis function for Mo/Tc and Au atoms. The experimental and/or simulated results are shown in the conference. Log 552. THE CONVERSION OF THE WESTCOTT CONVENTION INTO HGDAHL FOR THE USE OF NON-1/V NUCLIDES IN K0-NAA. van Sluijs, R. (1). (1) k0-ware, Heerlen, The Netherlands. In neutron activation analysis using the k0-standardization method, the activation reaction for “1/v” nuclides is described using the Høgdahl convention. “1/v”-nuclides have a 1/v cross-section for the neutron-gamma capture reaction in the thermal energy region. This makes the reaction rate independent of the shape of the neutron spectrum in this energy range. “Non-1/v” have a non-1/v shape in the thermal energy range so a description of the neutron flux is needed. Westcott’s convention allows to use these nuclides but needs different parameters to describe the neutron flux. Based on a mathematical conversion Westcott formula is converted into the Høgdahl convention without the loss of accuracy. This simplifies the use of the k0-method for non-1/v nuclides significantly. The nuclear parameters of the three most relevant nuclides, based on the flux description as defined by Westcott, are tabulated as well. Log 553. DOE JAPAN RESPONSE EXTENDED ANALYSIS OF SOIL CORES AND TRACE ACTINIDE ANALYSES. Wimer, N.G., (1). (1) Lawrence Livermore National Laboratory. The U.S. Dept of Energy field response for the Fukushima Daiichi Nuclear Power Plant accident in Japan (March 2011) performed extended analysis of a limited number of field samples. These included soil cores collected in six geographic locations of varying soil properties, and trace actinide analyses performed on several soil samples and swipe samples of deposition external to the nuclear power plant. After initial-screening gamma assays in Japan, such soil cores, soil samples, and deposition swipes were transported for U.S. fixed-laboratory gamma assay, physical composition analysis, and trace actinide radiochemistry. For soil cores, physical radiography results and soil diffusion profiles are reported, showing rapid diffusion of long-term dose relevant nuclides with diffusion rates depending on soil composition. Trace actinide swipe analysis results are reported for uranium and plutonium, reflecting Daiici reactor release of trace plutonium composition consistent with boiling-water-reactor fuel composition and trace uranium release not distinguishable from natural background. Remarks are made on Fukushima Daiichi source-term composition, variation in long-term exposure rate prediction considering soil diffusion of dose-contributing radionuclides, and the relevance of trace actinide analyses in determining reactor fuel damage conditions in nuclear power plant accidents.


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Log 554. LIVE IMAGING OF ION MOVEMENT IN PLANTS USING PLASTIC SCINTILLATORS. Sugita, R. (1); Sugahara, K. (1); Kobayashi, N.I. (1); Hirose, A. (1); Nakanishi, T.M. (1); Furuta, E. (2); Sensui, M. (3); Tanoi, K. (1, 4). (1) Graduate School of Agricultual and Life Sciences, University of Tokyo. (2) Faculity of Core Research, Ochanomizu University. (3) Tokyo Printing Ink MFG. CO., LTD. (4) Japan Science and Technology Agency. We developed a new real-time radioisotope imaging system (RRIS) to study ion movement in plants. The system can visualize ions and photosynthates distribution in a living plant. The mechanism of the system is that radiation emitted from the plant is converted to light by a scintillator and the light is captured by a CCD camera. The previous type of RRIS consisted of a fiber optic plate coated with CsI (Tl) as a scintillator (FOS). The FOS size was 10 cm x 10 cm. To get images, we used a few FOSs. It was hard to make larger size of FOSs because the cost was very expensive. Therefore we only used small size of test plants. In addition, the high cost of FOS makes it hard for other researchers to introduce the system in their facilities. In this study, to get images of large size plants such as mature rice, we tried to apply plastic types of scintillators to the RRIS instead of the FOS. Plastic scintillators are not so expensive so it makes easy to use large size of scintillators. We evaluated sensitivities and resolutions of radioactivity signal of several plastic scintillators using C-14 and P-32. Each C-14 labeled sucrose or P-32 labeled phosphate were spotted on a polyethylene terephthalate sheet respectively. Moreover, we tried to take images of large size plants. Log 555. AN IMPROVED METHOD FOR THE MEASUREMENT OF 210Pb BY LIQUID SCINTILLATION COUNTER. Chae, J.S. (1); Kwon, E.H. (1); Kim, Y.J. (1). (1) Korea Institute of Nuclear Safety. Lead-210 is naturally occurring radionuclide of the 238U decay series with half-life of 22.3 y. 210Pb is used as a useful tracer for geochronological studies, food chain research, and atmospheric science because of the wide distribution in soil, atmosphere and water due to the characteristic of naturally occurring radionuclide. Several 210Pb analysis methods such as measurements of 210Po by alpha spectrometry and 210Bi by a proportional counter, and direct measurement of 210Pb using gamma spectrometry in environmental samples have been used for various fields of study. Compared with these methods, the measurement of 210Pb by liquid scintillation counter has advantages such as short analysis time and relatively high detection efficiency. In this study, an improved method for the measurement of 210Pb in environmental samples using liquid scintillation counter (LSC) is devised. After the acid digestion of sample, Pb is purified through the extraction chromatography with Sr resin and precipitated as lead oxalate. Following re-dissolved, it is mixed with scintillation cocktail and measured by LSC. Unlike a previous study which divided three regions by energy level and selected only 210Pb region, all the spectra regions of in which signals of 210Pb, 210Bi, and 210Po are used for the calculation of the activity of 210Pb. This method involves a procedure for a correction of the blank value due to 210Pb activity in the Pb2+ carrier. This measurement technique has twice the detection efficiency as previous study, therefore it is expected to be useful for the analysis of environmental samples with low radioactivity concentration. Log 556. REFERENCE MATERIALS FOR NEUTRON ACTIVATION ANALYSIS OF ENVIRONMENTAL AND GEOLOGICAL MATERIALS: ROLF ZEISLER'S LEGACY FOR ANALYTICAL METROLOGY. Steinhauser, G. (1); Sterba, J.H. (2). (1) Leibniz University Hannover. (2) TU Wien, Austria. Neutron activation analysis (NAA) remains one of the most reliable analytical techniques for bulk and trace element concentrations in various (including difficult) sample matrices. The reliability and reproducibility of the method, however, depend much on the availability of well-characterized and homogenous reference materials. The apt reference material will not only match the range of the expected element concentrations of the sample material but also mimic the nuclear properties (e.g., neutron self-absorption) of the sample material. Reference materials made from natural starting materials, therefore have the potential to be superior to single element comparators or artificial multi-element comparators. In this talk, we exemplify the importance of the quality of the reference materials for the metrology in neutron activation analysis based on examples from our own work and highlight Rolf Zeisler's outstanding contributions to this important field.


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Log 557. RADIO-PURE MATERIAL ICP-MS ASSAY FOR PARTICLES PHYSICS EXPERIMENTS: LOOKING FOR THE HIGHEST INSTRUMENTAL SENSITIVITY AND THE SAMPLE TREATMENT OPTIMIZATION. Nisi, S. (1); Dafinei, I. (2); Ge, Z. (3); Zhu, Y. (3); Yan, Z. (3). (1) Laboratori Nazionali del Gran Sasso-INFN. (2) Sezione di Roma Uno-INFN. (3) Shanghai Institute of Ceramics Chinese Academy of Sciences. The experiments devoted to the searching for rare and low energy events in the field of elementary particles are characterized by very demanding requirements in terms of low radio active background. Thanks to its excellent sensitivity and haste, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) has become in the last decade one of the most successful techniques employed for the measurement of natural radionuclides traces in different materials. The ICP-MS instrumentation is therefore an unparalleled tool for the fast screening of materials to be used for the construction of rare event physics experiments. An analytical method for Th and U determination in Te/TeO2 was already developed at Laboratori Nazionali del Gran Sasso, INFN . The procedure was based on a quadrupole mass spectrometer measurement of samples previously prepared by matrix separation by chromatographic extraction. The current work shows how to obtain a further improvement of the detection limit at least one order of magnitude by the use of a double focusing mass spectrometer and the optimization of the chemical treatement of samples. The result ensures the reliable monitoring of the whole production process of the detector where Th and U ultra-traces have to be detected in different materials. In the case of Te, TeO2 and NaI powder to be used for the growth of crystals for DM search application, measurements were also made by ICPMS and gamma ray spectroscopy in order to check the secular equilibrium of the Th and U decay chains. Acknowledgements: This work was made with the contribution of the Ministry of Education, Universities and Research of the Italian Republic, MAECI-PGR04136 Log 558. MEASURING RADIONUCLIDES IN BRAZILIAN COMMODITIES. Gonzaga, C.L. (1); Fernandes, E.A.N. (1); Bacchi, M.A. (1); Fogaca, A.A. (1); Americo, P.T.Z. Laboratório de Radioisótopos (LRi), Centro de Energia Nuclear na Agricultura (CENA), Universidade de São Paulo, Brazil. Brazil is a major exporter of products from the agricultural sector, which has been supporting the economy of the country, even during crisis periods. The Chernobyl nuclear accident on April 26, 1986, has affected the international trade of commodities for requesting measurement of radionuclides in exported food. The following year, on September 13, 1987, the radioactive accident with 137Cs occurred in Goiânia, Goiás state, and then the issuance of certificates of analysis for Brazilian agricultural products has become mandatory by several importing countries, especially for the activity of radionuclides 134Cs and 137Cs. Since then, the Radioisotopes Laboratory (LRi) has been responsible for performing radiometric analyses for exporting companies and other interested parties, thereby contributing to overcome technical barriers imposed to the country. Several actions were implemented to ensure the quality of results, including frequent participation in laboratory comparisons and proficiency tests, important mechanisms to assess and demonstrate the metrological capability of analytical laboratories. In this context, LRi has been participating since 1993 in the National Intercomparison Program (PNI), a quality program on radionuclide measurement in environmental samples, coordinated by the Institute for Radioprotection and Dosimetry of the Brazilian Nuclear Energy Commission (IRD/CNEN) in collaboration with the Environmental Monitoring Systems Laboratory (EMSL), US Environmental Protection Agency. Brazil is the number one exporter by volume in beef and sugar. Over the past three decades, the importance of the analytical services provided by the LRi has significantly increased. A data survey on the radiometric analyses performed during 2015 has shown that about 80% of the sugar and 10% of the beef exported by Brazil was analyzed in the Radioisotopes Laboratory.


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Log 559. APPROACH TO THE CALCULATION OF GAMMA AMBEINT DOSE EQUIVALENT IN THE COMPARISON WITH G(E) FUNCTION. Le, N.T. (1); Tran, H.N. (2); Nguyen, T.K. (3). (1) Institute for Nuclear Science and Technology - Vinatom, Vietnam. (2) Duy Tan University, Vietnam. (3) Vietnam Agency for Radiation and Nuclear Safety, Vietnam. The paper presents an approach to calculation of gamma ambient dose equivalent in the comparison with the well-known approach applying G(E) function. The gamma pulse height spectra were measured using a portable Nal(TI) gamma spectrometer then gamma ambient dose equivalent were evaluated from the measured spectra applying two approaches. The first approach is applied the well-known G(E) function and the second one is the combination of ICRP 7 4 conversion factors and the simulated counting efficiency of Nal(TI) scintillation detector. Comparison of the gamma ambient dose equivalents obtained from these two approaches shows an agreement within 5% in case of the evaluation of gamma ambient dose equivalent in a neutron calibration field of 241Am-Be source. Log 560. ROLF ZEISLER'S ENDLESS PURSUIT -- EXPANDING CAPABILITIES OF INAA AND PGAA AT NIST. Chen-Mayer, H.H. (1), Chu, P.M. (1), Oflaz, R. (1), Paul, R.L. (1), Sharp, N.E .(1), Turkoglu, D.J. (2), Yu, L.L. (1). (1) Material Measurement Laboratory, NIST. (2) Center for Neutron Research, NIST. Post retirement, Rolf Zeisler continued to be a guiding force in our effort to modernize the data acquisition and analysis systems for NAA, to carry out various SRM measurements, and to develop instrumentation for coincidence measurements, mentoring young researchers along the way. We recount only a fraction of Rolf's numerous activities prior to his sudden passing. Taking on validating the new window-based NAA software and testing it in a variety of use-cases, Rolf was especially interested in loss free counting and live time corrections, and in making INAA analysis more user-friendly. In addition, Rolf led international comparisons using the same data with different peak search programs and with the new automated NAA software package. Rolf was instrumental in the As species determination using NAA and LC-ICP-MS, making over 200 INAA measurements for arsenic on filter paper, leading to the certification of SRM 3232 Kelp Powder. Simultaneously, Rolf was enthusiastically championing the on-going PGAA beamline upgrade effort to accommodate in-situ cold neutron beam INAA and PGAA, adapting the 4-detector coincidence system he developed for coincidence INAA for very short-lived nuclei and prompt gamma analysis. Rolf tirelessly performed experimental assessment of the idea; his final attempt was on Sunday 9/10/17, the day before the reactor's 4-month shutdown, when he modified shielding and placed a pair of HPGe detectors around the current PGAA sample position and performed coincidence measurements in neutron beam. Rolf left behind much unfinished work, but his legacy endures and inspires us to carry on. Log 561. CERTIFICATION OF AN INNOVATIVE SUGARCANE LEAVES REFERENCE MATERIAL BY NAA AND PGAA. Martínez, M-I.V. (1); Zeisler, R. U (2); Fernandes, E.A.N. (1); Bacchi, M.A. (1). (1) University São Paulo, Brazil. (2) NIST. Reference materials are important tools for analytical quality control of agricultural products. The CRMs should be as similar as possible to the samples, thereby avoiding commutability problems. This is relevant in the sucroenergetic sector, especially to evaluate nutritional status of sugarcane plants, since their leaves have differentiated chemical composition due to high contents of silicon and fiber. Thus, to fill this gap, an innovative reference material of sugarcane leaves with homogeneity certified for masses greater than 50 mg for major, minor and trace elements was developed at the Nuclear Energy Center for Agriculture, University of São Paulo, Brazil. Neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA), nuclear techniques of high metrological quality, were chosen for the final chemical characterization of the material at the National Institute of Standards and Technology, USA. For this, ten bottles were randomly selected out of the 410 bottles produced. NIST SRM1570 (Spinach leaves) and NIST SRM1572 (Citrus leaves) were used for analytical quality control. NAA allowed the determination of Al, Br, Ca, Ce, Cl, Co, Cr, Cs, Fe, Hf, K, La, Mg, Mn, Mo, Na, Rb, Sc, Sm, Th, V and Zn, corroborating the values obtained in previous studies performed with this material at CENA/USP. PGAA allowed the determination of B, Cl, Fe, K, Mn, N and Si. Similar mass fractions values were obtained for those elements determined by both NAA and PGAA in the sugarcane leaves reference material, SRM1570 and SRM1572.


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Log 564. BAN THE BEAUTY IN TRACE ELEMENT LABORATORIES - CONTAMINATION RISKS OF EYE SHADOW AND OTHER COSMETICS. Fernandes, E.A.N. (1); Bode, P. (2); Silva, G. (1); Bacchi, M.A. (1); Martinez, M.I.V. (1); Sarries, G.A. (1). (1) Nuclear Energy Center for Agriculture, Univeristy of Sao Paulo, Brazil. (2) Delft University of Technology; NUQAM, The Netherlands. Intervention levels for trace elements in biological materials are continuously reduced, facing analytical laboratories with increasing efforts to assess and control sources of potential contamination of samples. Pioneering work by Versieck et al. in the 1970s opened the insight to the contaminations during sampling of human biota by metals in needles, containers and preparation of the final analytical portion. One of the advantages of neutron activation analysis is the limited manipulation of the analytical portion, and less severe contamination risks compared to other analytical techniques requiring dissolution and dilution of objects prior to analysis. However, the risk of contamination during sampling and sample handling remains, also in NAA. Many sources of contamination in NAA have been mapped before, such as atmospheric dust, talc from surgical gloves, impurities in blanks, and abrasion of gold-containing jewelry. However, these sources of contamination appear to be negligible compared to the potential impact of cosmetics, applied to the analysts involved, from sampling to test portion preparation. In this contribution, we report on the composition of common cosmetics such eye shadow and various types of common skin creams, and their potential impact as contaminant to low-level trace element assessments. We conclude that for some analysis actions affecting private life-style have to be taken to assure minimization of contamination by cosmetics. Sometimes beauty have to be sacrificed for best results. Log 565. IDENTIFICATION OF THE KEY ISSUES AFFECTING ADSORPTIVITY OF MOFS TOWARDS ACTINIDES BY SYNCHROTRON RADIATION TECHNIQUE. Yuan, L.Y. (1); Tian, M. (1); Sheng, P.P. (1); Zhang, Z.H. (1); Chai, Z.F.(1, 2); Shi, W.Q. (1). (1) Laboratory of Nuclear Energy Chemistry, Institute of High Energy Physics, Chinese Academy of Sciences. (2) School of Radiological & Interdisciplinary Sciences, Soochow University. Although metal−organic frameworks (MOFs) offer a new platform for developing versatile sorption materials applied in actinide separation, yet coordinating the structure of MOFs and their functionality remains a great challenge. We here explored the key issues affecting adsorptivity of MOFs towards U(VI) and Th(IV) by synchrotron radiation technique, and the results were summarized as: (1) amine grafting on the framework of MOFs greatly enhances adsorbability of Cr-MIL-101 towards U(VI), and the enhancement dependents on the coverage and flexibility of the grafted amino group. Carboxyl derivatives of UiO-66 were found to be excellent sorbents towards Th(IV), in terms of the large Th(IV) uptake of more than 350 mg/g at pH 3.0, the short equilibrium time of 30 min., and ionic strength-independent nature. (2) Tuning missing-linker defects in the frameworks of UiO-66 expands the pore size and results in a larger number of reactive Zr-OH sites, which clearly facilitate U(VI) migration and loading in the defective MOFs. The combination of the defect-induced functionality improvement with the acid–resistant nature of UiO-66 substantiates the applicability of this material for actinide capture from acidic media. (3) U(VI) sorption on isostructural RE-MOFs is highly sensitive to ionic radii of metal node and represents strong periodic tendency. Deep mechanism insight shows that both the accessible pore volume of the MOFs and hydrogen-bonding interactions contribute to the strong periodic tendency. All above results indicate improved sorption efficiency by tailoring functional group, defect and metal node in MOFs for applications in actinides and/or other metal ion capture. Log 566. AVAILABILITY OF FIT FOR PURPOSE PROFICIENCY TEST (PT) MATERIALS. Jassin, L. (1). (1) Eckert & Ziegler Isotope Products. Laboratories depend on a flexible supply of PT materials consistent with the work they currently do and to remain accredited. While government institute supplied PT's may be suitable for a subset of a laboratory's sample matricies, this presentation will outline the availability and ISO 17043 accreditation of a commercial source of PT materials that covers a broader range of matricies and isotopes. These materials are available to both individual laboratories and in collaboration with governmental laboratories for their own distribution and administration.


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Log 567. COMPARATIVE STUDY OF ENRICHED URANIUM ANALYSIS BY TRIPLE-QUAD (ICP-QQQ) AND SINGLE-QUAD (ICP-Q-MS) WITHOUT CLEAN ROOM FACILITIES. Diane, T.L.Y. (1); Kin, P.B. (2). (1) Singapore Nuclear Research and Safety Initiative. (2) DSO National Laboratories. The environment contains uranium with natural abundance of 99.275 % U-238, 0.72 % U-235 and 0.005 % U-234. The high abundance of 238U in the environment hinders accurate determination of the isotopic ratio of enriched uranium in samples (235U/238U). Hence, it is important to understand the sources of the natural uranium during sample preparation prior to analysis. In our previous study, sources of natural uranium during lithium borate fusion procedures have been identified and the sensitivities of the analysis on enriched uranium (LEU, HEU and WGU) have been determined with a single-quad ICP-MS. The use of a triple-quad ICP-MS has gained popularity recent years due to its capability of overcoming isobaric interferences with reaction gases. In addition, it has improved sensitivity and lower background as compared to the single-quad. In this work, an Agilent 8900 ICP-QQQ is used for the analysis of enriched uranium samples with prior sample preparation by the automated lithium borate fusion (LeNeo, Claisse) method. Enriched uranium – LEU, HEU and WGU at different amount will be analyzed and the results are compared with the analysis done previously. Log 568. DETERMINATION OF THE EFFECTIVE HALF-LOFE OF 90Sr IN A HIGH CALCIUM MATRIX SOIL COLLECTED FROM FORMER US NUCLEAR TEST SITES IN THE MARSHALL ISLANDS. Herman, S. (1); Hamilton, T. (2); Glover, S. (1); Connick, W.(1); Spitz, H. (1). (1) University of Cincinnati. (2) Lawrence Livermore National Laboratory. From 1946 to 1958, the United States conducted 67 atmospheric nuclear denotations at Bikini and Enewetak Atolls in the northern Marshall Islands. Nuclear affected islands and atolls have only been partially resettled due largely to concerns about exposure to residual fallout contamination remaining in locally grown food plants such coconut (Cocos nucifera L.) and Pandanus fruit (Pandanus tectorius). Coral soils of the Marshall Islands are potassium deficient, contain low concentrations of clay minerals, and relatively large quantities of stable Ca and Sr. Consequently, the relative uptake of 137Cs and 90Sr in food plants is reversed from that typically observed in most continental regions. Manmade dose is dominated by 137Cs with 85 to 95% coming from the ingestion pathway. Uptake of 137Cs into plants can be efficiently remediated by addition potassium fertilizer. A portion of the labile 137Cs and 90Sr contained in coral soil is also removed from the root zone of plants over time through the action of rainfall percolating down the soil. The effective half-life of 137Cs in coral soil has been previously measured (T1/2 eff = 8.5 years) by time-dependent sampling and analysis of scrub vegetation, and fruit of coconut and Pandanus trees. Some physical loss of 90Sr is also expected to occur as shown by the continual presence of elevated levels of 90Sr (and 137Cs) residing in groundwater over past decades. However, the effective half-life of 90Sr has not previously been estimated by direct field sampling methods. In this study, we have used a similar approach to that previously used for 137Cs to determine the effective half-life of 90Sr in vegetation on Bikini Island based on time-dependent sampling of coconut trees. As remedial techniques are implemented to help reduce the 137Cs loading in food plants, the long-term behavior and dose contribution of 90Sr will grow in significance. Therefore, information on the effective half-life of 90Sr as presented in the paper will provide meaningful projections of 90Sr exposure over time in support of potential resettlement actions. LLNL-ABS-744449


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Log 569. AMERICIUM ISOTOPIC ANALYSIS VIA NEPTUNE PLUS MC-ICP-MS. Noyes, K.L. (1); Pratt, S.H.; (1) Tedrow, S.J. (1); Gajos, N.A. (1); Springer, K.W. (1). (1) Pacific Northwest National Laboratory. Chemistries were developed to separate and purify Am such that Am, Pu, and Np can be analyzed from the same sample aliquot. The chemistries separate Am from isotopic and molecular interferents in order to obtain accurate and precise Am isotopic. When a tracer (243Am) is added, quantitation and interelemental ratios can also be calculated. Isotopic analyses are completed on a Thermo Scientific Neptune Plus multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). By using the multi-collector detector array, 241Am and the 243Am tracer could be analyzed simultaneously, thus increasing the precision of the ratio measurement. A standard with known isotopic composition was made in house and used to correct the 241Am/243Am ratios for mass bias which improved the accuracy. Detection limits were less than 0.1 fg/mL for 241Am. Lead was found to be the most important interferent since it formed polyatomic ions with argon and chloride in the americium mass range. During development results were compared to SRM soil certificates and/or alpha energy analysis (AEA) of the same solutions. By using mass spectrometry to analyze Am, Np, and Pu, we can obtain lower uncertainties on the parent/daughter/granddaughter interelemental ratios and therefore calculate more precise sample ages. Additionally, detection limits are lower than those provided by AEA. Log 570. NEW EARLY WARNING INDICES FOR MONSOON ONSET AND WITHDRAWAL IN ALL REGIONS BASED ON COSMOGENIC RADIONUCLIDE 7Be. Terzi, L.; (1), Kalinowski, M. (2); Schoeppner, M. (2). (1) SCKCEN. (2) CTBTO. With 80 radionuclide detection systems worldwide, the International monitoring system (IMS) offers an unprecedented opportunity to use 7Be as an aerosol tracer for global meteorological processes. 7Be is a cosmogenic radionuclide and a vertical downward influx tracer that can be used as a new parameter for seasonal weather forecast and climate change. With a 53-day half-life and due to its physical properties 7Be is suitable to study large scale circulations such as Hadley and Ferrel cell dynamics. The close relationship between Hadley-Ferrel cell convergence zone and Monsoons make 7Be a reliable indicator for Monsoon onset and withdrawal forecast. Cross correlations of 7Be activity concentrations at different monitoring stations has the potential to serve as an early warning index for monsoon regions worldwide with over 30-day warning prior to monsoon onset and withdrawal. 7Be timeseries indicate the trend of atmospheric cell shift. Therefore, 7Be is a more reliable index than water content, as it is linked to the cause rather than the side effects of monsoon phenomena. This study focuses on monsoon forecast accuracy versus early warning time and how much deviation improves from a multi-year fit. Near-surface 7Be activity concentrations may help address outstanding challenges in monsoon research by integrating a new perspective across the disciplines of environmental radiation monitoring and meteorology. Log 572. THERMAL INDEPENDENT FISSION YEILD FOR Cs-136 FROM HIGHLY ENRICHED URANIUM. Friese J.I. (1); Estrada, J.H. (1); Pacific Northwest National Laboratory. The independent thermal fission yield for Cs-136 from U-235 currently has a 64% uncertainty in the evaluated fission yield database ENDF/B-VII.1. The evaluated fission yield is 5.53761E-5 with an uncertainty of 3.54407E-5 (64%). The radiochemistry team at Pacific Northwest National Laboratory has been measuring the Cs-136 fission yield from thermally irradiated highly enriched uranium (HEU) annually for more than ten years. The average fission yield for Cs-136 from U-235 thermal fission was measured to be 5.84E-5 with an uncertainty of 1.55E-6 (2.6%) which is the average of the five most recent measurements. The radiochemical separations and measurement methods will be described in additional to an evaluation of the individual annual measurements and the fission bases used in the calculation of the fission yield.


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Log 573. DEVELOPING AN ACCURATE ALGORITHM TO PREDICT POST-DETOANTION URBAN DEBRIS COMPOSITION (NUKES). Auxier, J.P. (1); Auxier, J.D. (2, 3, 4); Hall, H.L. (2, 3, 4). (1) Los Alamos National Laboratory. (2) Department of Nuclear and Radiological Engineering. (3) Institute for Nuclear Security. (4) Radiochemistry Center of Excellence. It is crucial that the collection time for surrogate melt glass created during a nuclear detonation is shortened to help decrease the total analysis time required. Fallout maps generated using programs similar to the Department of Defense Fallout Prediction System need to be updated to accurately depict damage from the thermal and shock effects of a weapon in an urban environment, and determine accurate melt glass matrices created from that urban location. This will help future researchers predict where the desired material will be deposited in specific cities. To complete this task, the software packages will be updated to account for city infrastructure, geographical topography, and weather conditions during the detonation. In order to collect and analyze samples in a short period of time, new codes must be developed to predict the composition of the urban debris created during the blast, and they must predict the kinematic effects the weapon has on the urban environment. With ever increasing improvements made in material strengths and building design, more urban infrastructure will survive after a weapon of mass destruction (WMD) detonation; hence altering both surrogate glass composition and large particulate dispersion patterns. To combat these problems, the Nuclear Urban Kinetics Effects Simulator (NUKES) was developed to account for soil composition, building type, infrastructure density, and type of WMD. This will allow the user to calculate the composition of urban debris in the lower continental 48 states within a short period of time; therefore, shortening the analysis time required in the laboratory. Log 574. STATUS OF THE NBL PROGRAM OFFICE NUCLEAR REFERENCE MATERIAL EFFORT. Mason, P.B. (1); Diawara, Y. (1). (1) NBL Program Office. The NBL Program Office was formed in May 2016 following a re-organization of the former New Brunswick Laboratory. The new organization will continue the mission of producing and distributing certified reference materials, conducting proficiency testing exercises, and enhancing the US's nuclear measurement quality. The NBL Program Office will work closely with collaborator and partner laboratories on production and certification of new reference materials. Additionally, the NBL PO has established a new storage and distribution facility at the Y12 site in Oak Ridge, which will perform packaging and shipping functions for the bulk of NBL reference mateirals. Additionally, the NBL Program Office and the Department of Homeland Security's Countering Weapons of Mass Destruction Office are collaborating on ensuring nuclear forensics reference materials are available to the measurement community Log 575. MEASUREMENT OF Se, Hg, Fe, Zn, K, Mn, Br, AND THE Hg:Se RATIO IN BRAIN TISSUE SAMPLES BY NEUTRON ACTIVATION ANALYSIS WITH RESULTS FROM THE MEMORY AND AGING PROJECT (MAP). Carioni, V.M. (1); Brockman, J.D. (1); Morris, M.C. (2); Ngwenyama, R.A. (1); Schell, L.A. (1); Spate, V.L. (1), Crane, S (1). (1) UMC Research Reactor. (2) Rush Medical School. In this paper, we present results from the measurement of Se, Hg, Fe, Cr, Zn, Mn, K, and Br in autopsied brain tissues from the Memory and Aging Project (MAP). A neutron activation analysis method was developed to measure Mn, K, and Br in the archived brain tissue samples 4 years after the initial measurement of Se, Hg, Fe, Cr, and Zn. Limits of detection obtained for Mn, K and Br were 0.03 µg g-1, 103.5 µg g-1 and 0.002 µg g-1 respectively. The Se, Hg, Fe, Cr, Zn, Mn, K, and Br levels and the Hg:Se ratio from the cerebellum, anterior putamen, white matter, mid-frontal cortex, and inferior temporal lobe regions in 10 autopsied brains of deceased participants of the Memory and Aging Project MAP study are reported.


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Log 576. RADIOGENIC RISK FROM CAP COMPUTED TOMOGRAPHY EXAMINATION IN SAUDI ARABIA. Alkhorayef, M. (1, 2). (1) King Saud University. (2) University of Surrey. Computed tomography (CT) examinations contributed greatly to diagnose different diseases. However, the radiation risk to the patient is significantly higher compared with other radiological examinations. Dose monitoring during CT scan procedures and re-evaluation of equipment and techniques is used, if necessary, are mandatory to keep the patients radiation risk as low as reasonable achievable. The objective of this study is to quantify patient risk from CT chest, abdomen and pelvis (CAP) procedures in Saudi Arabia. Four calibrated CT machines were used in this study. A total of 32 CT procedures were conducted. Effective dose has been estimated using the National Radiological Board software (NRPB-) software. Cancer risk probability has been estimated using conversion factors from International commission on radiological protection (ICRP).The mean air kerma Length Product (PKA) and CTDIvol was737.9 (409.7-1110.5) mGy.cm, 11.3 (7.8-16.3) respectively. The mean effective dose (mSv) was 11.1 (6.1- 16.7) and the cancer risk was 1 per 1500 CT procedures. The results of the study showed that the dose is higher compared to the most of previous studies, thus an urgent need for proper justification and optimisation to reduce the dose to its minimal value. Variation may be attributed to CT modality, patient pathology and technologist experience and awareness in selection of exposure parameters. Local diagnostic reference level (DRLs) was proposed from this study. Log 577. STAFF RADIATION DOSIMETRY IN DIAGNOSTIC NUCLEAR MEDICINE PROCEDURES. Sulieman, A. (1); Alkhorayef, M. (2, 3); Bradley, D (3, 4). (1) Prince Sattam bin Abdulaziz University. (2) King Saud University. (3) University of Surrey. (4) Sunway University. Staff and patient are exposed to un avoidable radiation exposure to a wide range of radionuclides, as 99mTc, 67Ga and 131I during nuclear medicine procedures. Although the frequency of the nuclear medicine is increasing, few data are available regarding ambient and patient exposure worldwide. The objectives of this study are to measure the ambient radiation and patient dose during certain nuclear medicine procedures. A calibrated survey meter and thermoluminescent dosimeters (TLDs- GR200A) were used to measure the ambient dose and staff dose, respectively. Prior to measurements, all TLD were calibrated in terms of air kerma free-in-air under reproducible reference condition using 99mTc with activity 10 mCi (370 MBq). All scan procedures were performed using MiE single head gamma camera (Orbiter 37 Gamma camera) after administration of 20 mCi, 4 mCi and 5 mCi of 99mTc. The average ambient dose equivalent rate equal to about 12, 25 and 10 µSv/h was obtained at distance of 1 m, at 1.3 m from patient during bone, renal and thyroid scan respectively. Injection room and hot lab has ambient dose equivalent rates of 1.0 and 30 µSv/h at the same order. The maximum dose were recorded at the reception area equal to 180 µSv/h. Staff may exposed to a dose range from 8.0 to 12.5 mSv annually. The dose values are within the safety limit in the light of the current practice.


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Log 578. SIDE-REACTION PRODUCTS IDENTIFIED FOR PHOTONEUTRON REACTION USING NATURAL AND MO-100 ENRICHED METAL TARGETS. Tkac, P. (1); Chemerisov, S.D. (1); Gromov, R. (1); Makarashvili, V. (1); Vandegrift, G.F. (1). (1) Argonne National Laboratory. Several alternative pathways exist for the production of Mo-99/Tc-99m medical isotope pair without use of enriched-uranium targets. Production of Mo-99 by Mo-100(gamma, n)Mo-99 reaction using an electron accelerator is one of the feasible options currently pursued by several commercial companies. This accelerator technology offers a viable alternative to reactor produced Mo-99, mostly due to lower start-up costs, commercial availability of electron accelerators, fast post-irradiation processing, and easier licensing procedures. On the other hand, use of enriched Mo-100 targets adds the requirement for recycle of irradiated enriched targets, and different generator technology. Here we report experimental results on identification of side-reaction products that form during the irradiation of natural and enriched Mo-100 targets. The presence of impurities introduced during the manufacturing of the targets can lead to production of longer-lived radionuclides, which if not removed after each target processing step, may lead to accumulation in the target material. Side-reaction products that were identified are Mo-90, Mo-93, Nb-95m, Nb-95, Nb-96, Nb-97, Nb-97m, Nb-98 and Zr-95. Comparison of experimentally determined normalized specific activities with those determined based on theoretical cross-sections will be presented. Moreover, presence of impurities introduced during the manufacturing of the targets can lead to production of longer-lived radionuclides, which if not removed after each target processing step, may lead to accumulation in the target material. Log 579. THE RELATIONSHIP BETWEEN RADON-222, RADON PROGENY, VENTILATION AND THE BUILD-UP OF LEAD-210 IN BONE. Spitz, H.B. (1). (1) University of Cincinnati. There is a wealth of information in the archival and public literature regarding health risks associated with exposure to elevated concentrations of Radon-222 (222Rn) and its short-lived progeny in uranium mines. This risk has been extrapolated to persons living in residential structures where natural geologic conditions favor to the emanation of 222Rn. Determining the risk for homeowners is complicated because indoor 222Rn exhibits large daily and seasonal variations that are caused by air handling systems and the natural exchange of air inside and outside the structures. The natural exchange can be magnified whenever severe changes in meteorological conditions occur. Persons living in homes where the average indoor 222Rn concentration is high may exhibit elevated Lead-210 (210Pb) in bone. This presentation will illustrate the challenge in assigning risk when exposure to radon and its short-lived progeny is so variable. Log 580. IRON OXIDE PELLET CHARACTERIZATION FOR EXPERIMENTS TO UNDERSTAND CHEMICAL SPECIATION OF NUCLEAR DEBRIS. Genda, T.P. (1); Smiles, D. (2); Shuh, D.K. (2); Springs, R.(3); Koury, D. (3); Czerwinski, K. (3); Knight, K. (4); Goldblum, B. (1). (1) The University of California at Berkeley. (2) Lawrence Berkeley National Laboratory. (3) University of Nevada, Las Vegas (4) Lawrence Livermore National Laboratory During a nuclear explosion, the abundance and composition of environmental material can impact the chemical form of debris as the fireball cools. Modern urban environments have different chemical compositions from historic U.S. above-ground nuclear tests, motivating additional research to better understand debris formation and chemical fractionation processes in different thermodynamic and chemical environments. In this work we use proxy experiments including characterization of speciation in reacted analog materials to better constrain the impact of redox on molten materials during fireball cooling. These data may help inform understandings of chemical speciation processes during condensation and solidification. In these experiments, a Portland cement/SRM 612 glass vitreous mixture is used as the surrogate debris matrix, and FeO, Fe2O3 and Fe3O4 are fabricated in pellet form for use in a diffusion couple. Following manual grinding of pellets and deposition of submicron particles onto 1x1 mm silicon nitride windows, initial XANES characterization of iron oxidation states of micron-sized particles was performed using a scanning transmission x-ray microscope. Initial results reveal the challenges of maintaining homogenous oxidation states in iron samples throughout the fabrication process. Future work will optimize these experiments and aim to characterize oxidation states within uranium oxides, followed by diffusion couple experiments of uranium and iron species in the presence of surrogate urban glasses in order to observe fine-scale speciation across the diffusion profile. LLNL-ABS-746607


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Log 581. BIOGEOCHEMICAL ALTERATION OF URANIC PARTICLES UNDER FLOWING CONDITIONS. Bower, W.R. (1, 2, 3); Morris, K. (2, 3); Mosselmans, J.F.W. (4); Lyon, I.C. (2); Fallon, C.M. (1, 3); Fuller, A.J. (1, 3); Livens, F.R. (1,3); Law, G.T.W. (1, 3). (1) School of Chemistry, The University of Manchester, UK. (2) School of Earth and Environmental Science, The University of Manchester, UK. (3) Dalton Nuclear Institute, The University of Manchester, UK. (4) Diamond Light Source, UK. Decades of nuclear energy production and atomic weapons development has led to numerous authorised and accidental releases of radioactive material to the environment. Current impact assessments take little account of the fact that many radionuclides are dispersed in particulate form and lack of knowledge concerning the biogeochemistry of particle-bound radionuclides makes prediction of their impact difficult. Here, uranic micro-particles (refined U ore (UO3) and surrogate yellowcake (U3O8)) were emplaced in flowing sediment / groundwater column systems, using sediments representative of the UK’s Sellafield site. Two contrasting groundwater chemistries were then used to alter the particles under oxic and anoxic (iron to sulfate reducing) conditions; columns were then sacrificed for analysis after ~6 and ~12 months. Using the microfocus spectroscopy beamlines at the Swiss Light Source (X05-LA) and the Diamond Light Source (I18), elemental mapping and targeted U LIII XAS measurements were used to document the dissolution of the U particles, and follow the subsequent migration of U throughout the sediment; followed by eventual precipitation of secondary U phases (under both oxic and anoxic conditions). The results demonstrate the complexity of U association with the sediment/organic fractions at the micro-scale, whilst targeted µEXAFS and XANES energy mapping across regions of interest, reveal intermediate and end product U speciation. This fundamental knowledge can be used to expand models of U biogeochemistry at contaminated nuclear sites and inform nuclear incident response. Log 583. ANALYSIS OF ACTINIDES IN ADVANCED PUREX PROCESS BY X-RAY BASED SPECTROSCOPIC METHODS. Ye, G. (1). (1) Department of Radiochemistry, China Institute of Atomic Energy. The analytical methods especially X-ray based advanced spectroscopic ones for uranium, neptunium and plutonium in various concentrations were established and applied in advanced PUREX process, which were developed CRRL (China Reprocessing and Radiochemistry Laboratory) of CIAE (China Institute of Atomic Energy). These methods include K-edge and L-edge analysis for ligands and U or Pu and U/Pu solutions; separation-spectrometer for the determination of Pu with different valences; α-energy spectrometry for Np; ICP-MS for trace amount of Np and Pu; time resolved laser fluorescence spectroscopic analysis for actinide speciation in aqueous solutions, X-ray diffraction spectrometry for actinide coordination compounds in solid states. Satisfactory results are given and future perspectives in this field are provided.


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Log 584. MULTIPURPOSE NAA AUTOMATED IRRADIATION AND COUNTING SYSTEM. Muftuoglu, A. (1); Muftuoglu, T .(2); Koclas, C. (3); Cilian, C. (3). (1) Canadian Nuclear Safety Commission, Canada. (2) Targe Industrial Systems, Turkey. (3) Polytechnique Montreal, Canada. Over the last four decades, SLOWPOKE pool-type research reactor of Polytechnique Montreal is extensively used for neutron activation analysis (NAA). Today, the number of samples received for NAA increased extensively to more than ten thousands samples per year, and it necessitates several labor hours and manpower. Therefore, new fully automated irradiation and counting system has been designed and installed in the SLOWPOKE NAA Laboratory at Polytechnique Montreal. Adding a shielded decay station is a further automated step which reduces the analyzing time between 2 to 20 times depending on the irradiated material. The new system is instrumented by double photo sensors at the inlet of the irradiation site and equally of the detector receiver, not only to control the irradiation and the decay time precisely but also to ensure that sample arrived into the reactor irradiation site or to detector counting station. Since, it is very important to shut down the reactor in case of system or power failure, several safety features are added as, redundant mechanical insertion of vials and use valves with pneumatic bypass. The detector (Ortec-HPGe) is connected to digital spectrometer (DSPEC-Pro) and sample receiver can be positioned at three different distances from the detector (0.00cm, 4.00cm and 10.00cm). The control and data acquisition (such as; irradiation, decay and counting times and pneumatic valve times) for sampling, irradiation, counting and disposal of the samples is done with in-house developed Visual Studio 2015 software program and National Instrument NI USB-6216 hardware. The system is used in various modes, cyclic, pseudo-cyclic, and single irradiation of large batches of samples with or without decay station. The NAA protocols can be resumed but not limited to: irradiation time of 20 seconds up to one hour, decay time of 4 seconds up to 12 hours, and counting time of 40 seconds to 3 hours. Log 585. PRIMARY STANDARDIZATION OF THE MASSIC ACTIVITY OF A PROTACTINIUM-233 SOLUTION. Fitzgerald, R. (1); Pibida, L. (1). (1) National Institute of Standards and Technology. Protactinium-233 (Pa-233) is used as a tracer for radiochemical analysis and is of particular interest as an isotope dilution mass spectrometry (IDMS) spike for measurement of Pa-231. To this end, we present massic activity determinations by two methods for a Pa-233 solution. This solution was prepared by separation from a high-purity Np-237 material at Lawrence Livermore National Laboratory and is being characterized at multiple labs as part of a Pa-231 reference material production project. One activity determination method was 4 pi beta-gamma anti-coincidence counting using multiple gamma-ray gates in a multi-dimensional extrapolation model. This is considered to be a primary standardization method, which is self-calibrating for efficiency and not directly dependent on nuclear decay data. A Monte Carlo radiation transport simulation was used to reduce uncertainty due to the extrapolation parameters. An independent massic activity determination was completed by gamma-ray spectrometry using 5 HPGe detectors using 5 gamma-ray lines. The anti-coincidence and gamma-ray spectrometry results have combined standard uncertainties of about 0.3 % and 1.0 % respectively and agree with each other to within their combined uncertainty. This anti-coincidence method uncertainty is sufficient, in conjunction with the Pa-233 half-life, for an independent determination of molality that is consistent with IDMS Pa-233 spike molality uncertainties used in practice.


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Log 586. THE IMPACT OF GEOLOGIC PARAMETERS AND WATER INFILTRATION ON THE IMPRINTING OF XE-133. Johnson, C. (1); Lowrey, J.D. (1); Rockhold, M.L. (1); Waichler, S.R. (1); White, M.D. (1); White, S.K. (1). (1) Pacific Northwest National Laboratory. Detection of radioactive xenon in soil gas samples is a proposed key indicator of an underground nuclear explosion. However, recent experiments have shown that atmospheric radioxenon passing over a sampling site can be pressed into the shallow subsurface by barometric pressure changes. This imprinting process has been shown to increase the subsurface radioxenon concentrations about 10% of atmospheric concentrations, even when the radioxenon passes over the site as a discrete plume. The Subsurface Transport over Multiple Phases, or STOMP, simulator is used to examine the impact of seven geologic parameters and water infiltration on the imprinting of radioxenon from a transient plume during two pressure scenarios. In particular, the maximum Xe-133 concentration at two meters was examined along with the time of maximum concentration at that depth. Soil conductivity was found to be the dominant factor in the amount of xenon imprinted to two meters, particularly in the case when plume passage coincides with increasing pressure. The van Genuchten n parameter and water infiltration also impacted the results to a lesser extent, while the water table depth and the dispersivity of the medium were identified as having a minor impact. The porosity of the medium, the van Genuchten . parameter, and the residual moisture content of the medium were also examined, but they were found to have no significant impact on the imprinting process. Log 587. SUBSURFACE GAS TRANSPORT MODELING TO SUPPORT NOBLE GAS MIGRATION EXPERIMENTS. Johnson, C. (1); Rockhold, M.L. (1); Lowrey, J.D. (1); Kirkham, R.R. (1); McIntyre, J.I. (1); Olsen, K.B. (1); White, M.D. (1); White, S.K. (1). (1) Pacific Northwest National Laboratory. Two noble gas migration experiments have been performed at the site of an underground nuclear explosion on the Nevada National Security Site. In these experiments, noble gases and stable tracers were injected into the underground shot cavity and allowed to migrate from the cavity to various sampling locations around the site. A subsurface transport model was developed using the Subsurface Transport over Multiple Phases (STOMP) code and was designed to match both the site characteristics and the operational characteristics of the injection. The concentrations of both tracers were predicted at specific points around the injection site and compared to the results of gas samples collected from those same points over a period of months.

Log 588. A METHOD FOR BATCH DESORPTION OF CESIUM-137 FROM POST-DETONATION SOILS USING READY-FOR-USE DIALYSIS DEVICES. Hoffman, K. (1); Durrant, C. (2); Begg, J. (2); Kips, R. (2); Martinelli, R. (2); Glover, S. (1); Connick, W. (1); Spitz, H. (1); Hamilton, T. (2); Zavarin, M (2); Kersting, A. (2). (1) University of Cincinnati. (2) Lawrence Livermore National Laboratory. Safely managing and controlling the subsurface migration of radioactive contaminants in the environment has been a challenge for scientists as long as nuclear technologies have existed. To continually improve management practices and protocols, it is necessary to fully understand the desorption processes that influence the transport of radionuclides. Additionally, many of the radionuclides of concern are present in the environment at low concentrations, complicating the measurement of the radionuclides. This work describes the development of an inexpensive and simplified experimental approach for characterizing the desorption of cesium-137 from bulk contaminated soils. The clay mineral illite, which has a high affinity for cesium, was used to drive desorption of cesium from the soil. The change in 137Cs concentration over time was then monitored by gamma spectroscopy. To simplify the counting procedures, the illite was placed in ready-to-use dialysis devices (Spectra/Por® Float-a-lyzers®), physically separating the mineral from the sample. The dialysis device was easily removed and returned to the experimental set-up each time that the sample was counted. This method was tested with a variety of soils collected from coral atolls with significant 137Cs contamination. Preliminary data have shown the radionuclide desorbing at a slower rate than expected from these calcium-rich soil samples. As a result, further studies will be conducted to better understand the composition and behavior of these soils with regards to radionuclides. Monitoring of the 137Cs concentration for the original desorption experiments is also ongoing and will continue for at least twelve months to observe the long-term behavior of this radionuclide.


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Log 589. PRODUCTION OF Ac-225 FOR RADIOTHERAPY, A US DOE TRI-LABORATORY (ORNL, BNL, LANL) PROJECT. John, K.D. (1); Balkin, E.R. (2); Birnbaum, E.R. (1); Boll, R.A. (3); Brown, A.E. (3, 4); Brugh, M. (1); Cooley, J.C. (1); Copping, R. (3); Cutler, C.S. (5); Davern, S.M. (3); Denton, D.L. (3); Fassbender, M. E. (1); Felker, K. (3, 4); Ferren, M.D. (3, 4); Fitzsimmons, J.M. (5); Garland, M. (2); Griswold, J.R. (3); Mastren, T. (1); Medvedev, D.G. (5); Mirzadeh, S. (3); Murphy, K.E. (3); Nortier, F.M. (1); Owens, A.C. (3); Runde, W.H. (1, 4); Stracener, D.W. (3); Vermeulen, C.E. (1); Wyant, L.E. (3). (1) LANL. (2) US DOE. (3) ORNL. (4) NIDC. (5) BNL. A general overview and update of the US Department of Energy Isotope Program’s Tri-Lab (ORNL, BNL, LANL) Research Effort to Provide Accelerator-Produced 225Ac for Radiotherapy will be presented with focus on accelerator-production and final product isolation methodologies. In addition, impacts on the radionuclidic quality of the accelerator-produced 225Ac product as well as the product quality with respect to a 225Ac /213Bi generator application will be presented. Specifics regarding ongoing evaluations of the accelerator-produced 225Ac by independent end-users related to pre-clinical dosimetry and toxicity studies and broad logistical challenges associated with the accelerator-based production approach will also be discussed. Log 590. EFFECT OF PROCESS VARIABILITY ON MORPHOLOGY AND CHEMICAL SPECIATION OF AMMONIUM DIURINATE. Wagner, G.L. (1); Anderson-Cook, C. (2); Gravelle, J.D. (3); Scott, B.L. (4); Sentz, K. (5); Wozniak, N. (6); Wilkerson, M.P. (1). (1) Chemistry Division, Los Alamos National Laboratory. 2) Statistical Sciences Division, Los Alamos National Laboratory. 3) Department of Chemistry and Biochemistry, Miami University. 4) Materials Physics and Applications Division, Los Alamos National Laboratory. 5) Intelligence and Space Research Division, Los Alamos National Laboratory. 6) Materials Science and Technology Division, Los Alamos National Laboratory. Ammonium diurinate (ADU) is an important material produced during the stepwise processing of uranium ore into various uranium oxides. Understanding the synergistic effects of various processing parameters is an important part of being able to identify morphological and chemical signatures of materials with unknown origins. Our experimental strategy employs the synthesis of 21 different ADU precipitates based on 5 reaction variables using I-optimality statistical design. This establishes a variety of precipitation reaction conditions which effect material morphology and chemical composition. ADU products were characterized using color analysis, SEM, and powder XRD with the results clearly demonstrating an effect of reaction conditions on the physical and chemical characteristics of the products. The synthesis and characterization of compounds in this manner provides a useful test bed for inverse prediction statistics while developing a meaningful understanding of the importance the effects of processing parameters play in nuclear forensics. LA-UR-17-30821Log 591. HIGH ACCURACY NUCLEAR DECAY DATA WITH MAGNETIC MICROCALORIMETER GAMMA DETECTORS.Friedrich, S. (1); Kim, G.-B. (1); Hummatov, R. (2); Boyd, S.P.T. (2). (1) Lawrence Livermore National Laboratory. (2) University of New Mexico. Gamma detectors based on magnetic microcalorimeters (MMCs) offer more than an order of magnitude higher energy resolution than conventional high-purity Ge (HPGe) detectors. They also have a linear and reproducible response function that is constant with energy and can be described with only a few parameters. These properties make MMCs well-suited to improve the accuracy of nuclear decay data used for non-destructive assays (NDA) in nuclear safeguards and forensics. We are developing MMC gamma detectors based on Au absorbers and paramagnetic Ag:Er sensors. These detectors have achieved an energy resolution below 50 eV FWHM at an operating temperature of 10 mK, and have been scaled to small detector arrays for increased sensitivity. We demonstrate that MMCs can be used to increase the accuracy of gamma-ray energies to ±~1 eV, and illustrate how their performance complements HPGe detectors to improve literature values of nuclear decay data.


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Log 592.ANALYSIS OF POST-IRRADIATED NUCLEAR FUELS USING THE CAPABILITIES OF THE ANALYTICAL LABORATORY AT INL.Carioni, V.M.O. (1). (1) Analytical Laboratory, Idaho National Laboratory. The Analytical Laboratory at the Materials and Fuels Complex of the Idaho National Laboratory is equipped for the characterization of nuclear materials, particularly components of nuclear fuels. The Laboratory contains six interconnected hot cells for the remote handling of highly active irradiated materials and numerous air atmosphere glove boxes and radiological fume hoods. Elemental and isotopic analytical capabilities include multiple detectors for alpha, beta, and gamma spectrometry; two inductively-coupled plasma (ICP) optical emission spectrometers; a gas mass spectrometer (MS); a multi-collector ICP-MS; a thermal ionization mass spectrometer (TIMS); and a quadrupole ICP-MS. A limitation of ICP-MS in the analysis of complex nuclear samples is the formation of polyatomic ions in the plasma, which can result in isobaric interferences and inaccurate results. As a response to these challenges, the newest addition to the Laboratory is an Attom ES High Resolution ICP-MS from Nu instruments, which has been attached to a radiological hood. This HR-ICP-MS is a double focusing instrument, and its high resolution feature (>10000 RP) allows for the avoidance and removal of interferences, e.g., the removal of Cu and Zn argides from Rh, Pd and Ag isotopic signals, with enhanced sensitivity and fast mass scanning capabilities. Methods for the correction of oxide interferences are also being evaluated by coupling a desolvating nebulizer to the HR-ICP-MS. Methods developed using the HR-ICP-MS have the potential to increase the accuracy of the results on the determination of several isotopes in post-irradiated nuclear fuels. Log 593. OXYGEN ISOTOPE ANALYSIS OF URANIUM OXIDES USING NF3 FLUORINATION.Klosterman, M.R. (1); McDonald, L.W. (1). (1) University of Utah. Oxygen isotope ratios of uranium oxides are known to correlate with those of the fluids from which they precipitated. The variety of processing routes utilized in the nuclear fuel cycle, from ore concentration through enrichment, will therefore contribute to a wide variation in δ18O values encountered among uranium oxides. Application of this information for nuclear forensics purposes requires an understanding of the oxygen isotopic fractionation induced through certain processing conditions. In this study, UO2 samples were synthesized using waters enriched in 18O from both a traditional route precipitation as UO4, followed by calcination and hydrogen reduction – and through direct photochemical reduction. To analyze changes in the 18O/16O ratios of these samples, a thermal fluorination technique was employed using NF3 as a fluorinating agent. Results of oxygen isotope fractionation arising from variation in synthetic methods will be discussed, along with their implications for future radioanalytical and nuclear forensic investigations.Log 594. ON NUCLIDES MINING FROM USED NUCLEAR FUEL. Kajan, I. (1,); Schumann, D. (1). (1) Paul Scherrer Institute, Switzerland. Apart from the energy production, used nuclear fuel can be a source of radionuclides for further scientific purposes. A pilot system for such an isotope mining from high level active waste is currently under development at PSI in order to extract minor actinides (244Cm, 245Cm, 246Cm) as well as some isotopes from the lanthanides series. The system consists of several extraction chromatographic columns where extractions and consequent separations will be performed. In order to selectively remove cesium from the high level active waste as the main dose rate emitter a column with ammonium molybdophosphate impregnated silica gel will be utilized. Major actinides (U+Pu) will be extracted by TBP impregnated resin and consequently eluted. Extraction and separation of lanthanides and minor actinides from the nitric acid matrix will be performed on TODGA resin with utilizing hydrophilic SO3Phen-BTP as a selective complexing agent for the elution step. Collected fraction with minor actinides will undergo further separation in order to obtain pure fractions of Curium and Americium. Separations of lanthanides from each other will be performed with utilization of TODGA resin column and diethylenetriaminepentaacetic acid as an elution agent. The system was already tested in batch experiments and consequently distribution constants for chosen isotopes were obtained on TBP and TODGA resin materials from nitric acid matrixes. As a next step tests will be carried out with diluted sample of high-level active waste solutions in order to test system performance.


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Log 595. NATIONAL TECHNICAL NUCLEAR FORESNICS: U.S. APPROACH TO CAPABILITY SUSTAINMENT. Zeitoun, A. (1). (1) US Department of Homeland Security – Countering Weapons of Mass Destruction Office. In the event of a nuclear detonation in the United States (U.S.), the interdiction of a nuclear device, or the seizure of nuclear or other radiological materials, there will be tremendous pressure to attribute the source of the material, establish responsibility, and ensure the prevention of another incident. Along with intelligence and law enforcement investigations, nuclear forensics is one of the three pillars supporting attribution. The field of nuclear forensics includes the collection, analysis, and evaluation of radiological or nuclear materials, devices, and debris after an event or interdiction. The nuclear forensics scientific workforce is situated primarily in national and defense laboratories, but in recent decades has experienced a decline in numbers. The Countering Weapons of Mass Destruction Office (CWMD) has implemented an expertise development program in order to off-set these declines and sustain a workforce of educated and trained scientists skilled in areas needed for nuclear forensics. Since its inception in 2008, the National Nuclear Forensics Expertise Development Program (NNFEDP) has placed 56 Ph.D.’s directly into national laboratories and U.S. federal agencies, maintaining the technical expertise required to execute the Nation’s nuclear forensics mission.As the NTNF mission steward, CWMD is focused on assuring an enduring nuclear forensics workforce required to execute the Nation’s nuclear forensics mission. CWMD works in close collaboration with the Departments of Defense, Energy, and Justice in administrating the NNFEDP which works to build a nuclear forensics workforce of recognized technical experts through research collaboration between and among academia, the national and defense laboratories, and the NTNF federal community. Log 596. DISCRIMINATING THE CONTRIBUTION OF GLOBAL FALLOUT AND CHERNOBYL TO ANTHROPOGENIC FALLOUT RADIONUCLIDE INVENTORIES IN SOILS OF EUROPE. Evrard, O. (1); Meusburger, K. (2); Van Oost, K. (3); Borelli, P. (4); Ketterer, M. (5); Mabit, L. (6); Lefèvre, I. (1); Alewell, C. (4); Panagos, P. (7). (1) Laboratoire des Sciences du Climat et de l’Environnement (LSCE, joint laboratory CEA/CNRS/UVSQ), France. (2) Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Switzerland. (3) TECLIM, Earth and Life Institute, Université catholique de Louvain, Belgium. (4) Environmental Geosciences, University of Basel, Switzerland. (5) Chemistry Department, Metropolitan State University of Denver. (6) Soil and Water Management & Crop Nutrition Laboratory, International Atomic Energy Agency, Austria. (7) European Commission, Joint Research Centre, Sustainable Resources, Italy. Fallout radionuclide inventories are increasingly used to derive soil redistribution rates in watersheds across the world. However, one of the main prerequisites of this assessment method consists in establishing a baseline fallout map based on the inventories measured at reference undisturbed sites. This prerequisite is particularly difficult to obtain at continental scales, because of the extensive work required to collect and analyse the samples. Moreover, in Europe, an additional difficulty arises from the potential contribution of two main sources to the fallout radionuclide inventories: the global fallout and the Chernobyl fallout. To overcome these difficulties, we used a selection (n=156) of topsoil (0-20 cm) samples collected in 2009 at undisturbed locations under permanent grassland in the framework of the European LUCAS Survey. The selected samples were analysed for Cs-137 by gamma-spectrometry (n=156) and for Pu-239+240 (n=106) by ICP-MS. Preliminary results show that the use of the Cs-137/Pu-239+240 activity ratios provide a reliable proxy to discriminate between both sources of radioisotopes. The spatial variability of Cs-137 Chernobyl fallout across Europe can be re-assessed based on the updated map produced using advanced geostatistical methods. The measurement of Am-241 as a surrogate of plutonium was also explored through the gamma spectrometry analyses conducted on the samples showing the highest Pu concentrations. In the future, the current investigation will be extended to samples of the LUCAS bank collected at both erosion and accumulation sites in order to calculate the cumulative soil redistribution rates since the 1960s in cultivated land across Europe.


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Log 597. REVEALING LI DISTRIBUTION AND TRANSPORT IN BATTERY MATERIALS WITH NEUTRON DEPTH PROFILING. Lyons, D.J. (1); Tan, C. (2); Cao, L.R. (2); Co, A.C. (1). (1) Chemistry and Biochemistry, The Ohio State University. (2) Nuclear Engineering, The Ohio State University. In situ Neutron Depth Profiling (NDP) provides temporal and spatial measurement of Li during lithiation and delithiation process. This allows the direct measure of Li position, their transport and diffusion behavior which provides insight to guide materials design. NDP has allowed us to investigate preferential Li nucleation, Li trapping and Li transport in intermetallic materials like LixSny, LixSiy and LixAly and intercalating materials like LiNiMnCoO3. The technique has also provided us understanding of the role of the solid electrolyte interface (SEI) formed between the electrode and various combinations of electrolytes, through their Li transport properties. The presentation will focus on decoupling chemical reactions enabled by in-situ NDP. Log 598. QUASI - NON-DESTRUCTIVE INVESTIGATION OF ACTINIDE PARTICLES - RECENT APPLICATIONS OF THE SECONDAY NEUTRAL IONISATION SIMS. Walther, C. (1); Bosco, H. (1); Hamann, L. (1); Weiss, M. (1); Franzmann, M. (1, 2) , Wendt, K. (2). (1) Institute for Radioecology and Radiation Protection, Leibniz University Hannover. (2) Institute of Physics, Johannes Gutenberg-Universitaet Mainz, Germany. From accidents at civil or military installations, actinides were released in fuel fragments of typically micrometer size. Frequently, the isotopic composition of single particles is required for unambiguous source identification. The composition analysis and spatial imaging of these particles in environmental samples necessitates an excellent sensitivity, complete suppression of any kind of background and isobaric contamination in combination with high spatial resolution while maintaining the natural structure of the sample. The new resonant Laser-SNMS system at the IRS Hannover was developed to achieve these specifications by combining the high element selectivity of resonance ionization with the non-destructive analysis of a static TOF-SIMS instrument exhibiting spatial resolution down to 70 nm. In contrast to dynamic SIMS, the present system works quasi non-destructive. We demonstrated sequential measurements of U, Pu, Sr, Cs and Tc isotopic compositions as well as spatially resolved full mapping of all elements on one single um-sized particle, which after analysis is still available for subsequent investigations. By use of synthetic samples we demonstrated the effective suppression of interfering isobaric elements. In MOX fuel, Pu-238 and U-238 were successfully discriminated. For preselection of sample material, the technique of alpha track analysis was successfully applied and is presently further refined for application on environmental bulk samples. Furthermore, since surface charging effects play a minor role in static SIMS, no kind of sample preparation is required. We present Laser-SNMS Measurements on Pu and U containing samples including natural minerals from Afghanistan collected close to Kabul and containing enhanced levels of natural radioactivity and particles from the Chernobyl exclusion zone and from the evacuated zone close to the Fukushima Daichii nuclear power plant.


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Log 599. EFFECTIVE DESORPTION OF TRITIUM FROM DIVERSE SOLID MATRICES AND ITS APPLICATION TO ROUTINE ANALYSIS OF DECOMMISSIONING MATERIALS. Kim, D, (1,2); Warwick, P.E. (2); Croudace, I.W. (2). (1) Korea Institute of Nuclear Safety. (2) University of Southampton. Tritium extraction from materials is most commonly carried out using oxidative thermal desorption in purpose-built furnace systems and typically involves trapping the product in a water bubbler which is sampled for measurement using Liquid Scintillation Counting (LSC). The performance of perhaps the most widely used commercial system, the Raddec Pyrolyser, has been evaluated for a broad range of sample types. A range of parameters that were expected to affect tritium desorption and recovery was studied. These included sample heating rates and end-point temperatures, carrier/oxidant gas flows, catalyst temperature, bubbler trapping and carry-over/memory effects. A catalyst such as platinised alumina is used to ensure the quantitative oxidation of volatile combustion products to HTO and CO2. This also ensures that the trapped decomposition do not colourise the bubbler solutions that are subsequently sampled for LSC. A comprehensive range of tritium evolution profiles were determined for a range of sample types and were obtained by systematically changing bubblers at a set of progressively increasing temperatures. These experiments showed the maximum heating temperature and total combustion time required for the complete recovery of tritium from samples and is shown to depend on the sample matrix types and the 3H form. These evolution profiles need only to be determined once and are readily transferable to other Pyrolyser systems. For example tritiated water is rapidly liberated from samples at temperature around 100°C whereas 3H substituted for structural H in organic species can require a temperature in excess of 300°C to be released. Higher temperatures (up to 900°C) are needed to liberate 3H produced via neutron capture reactions by trace Li within a material (e.g. graphite or concrete). Log600.THEPRODUCTIONOFPERFORMANCETESTINGMATERIAL-VS-CERTIFIEDREFERENCEMATERIAL.Backstrom,L.G.(1,2).(1)RadiologicalandEnvironmentalSciencesLaboratory.(2)U.S.DepartmentofEnergy. The United States Department of Energy’s Radiological and Environmental Sciences (RESL) Program has been producing radiological proficiency testing materials and testing laboratories analytical capabilities for decades. In 2012, RESL started producing a wide range of radiological certified reference materials. In 2015, RESL began producing special radiological performance testing material, for use in its Mixed Analyte Performance Testing Program to address the wide and variable needs of the radioanalytical community. The aim of this presentation will be to point out the differences between Performance Testing Materials and Certified Reference Materials and the uses of both of the materials. The importance of defining the purpose of the testing scheme, various performance testing criteria, testing the homogeneity, verification and stability of the reference materials produced for these testing schemes will be discussed. This presentation will, hopefully, lead to further discussions about the importance of the capability of the producers of these materials to maintain traceability at the secondary level when the primary National Metrological Institutes do not produce these materials. RESL is a fully accredited ISO/IEC-17043 Proficiency Testing Provider and an ISO/IEC-17034 Certified Reference Material Producer.

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