nks radioactive particles in a nordic context – hot ii · “radioactive particles in a nordic...
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NKS Radioactive particles in a Nordic context – Hot II
Brit Salbu & Ole Christian LindIsotope laboratory, Norwegian University of Life Sciences
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Background “Radioactive particles in a Nordic context”- Hot II
A significant fraction of radionuclides will be present as discrete particles of various characteristics in any nuclear event in which refractory elements are released
“Radioactive particles are defined as localised aggregates of radioactive atoms that give rise to an inhomogeneous distribution of radionuclides significantly different from that of the matrix background” (IAEA, CRP 2001-2007)• Aquatic environment: >0.45 μm and less than 1
mm - fragment(IAEA CRP, 2001)• Aerosol particles in air: 1 nm - 100 μm (Manahan,
1994)
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Background “Radioactive particles in a Nordic context”- Hot II
Radioactive particles represent point sources of short- and long-term radioecological significance, and the
The failure to recognise their presence may lead to significant errors in the short- and long-term radiological evaluation of the impact of radioactive contamination at a particular site
A series of existing and potential sources (e.g. Kola Nuclear Power Plant or nuclear terrorist attacks) can contribute with radioactive to the Nordic countries
The Nordic radioecological community would benefit from acquiring more knowledge on
• the phenomenon of radioactive particle contamination • competence on both classical and novel analytical
techniques available for characterisation of radioactive particles
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
IMPACT OF RADIOACTIVE PARTICLESSHORT TERM
Radioactive particles can be subject to atmospheric transport
Problems within micro-dosimetry• Skin dose• Inhalation- transmembrane uptake• Ingestion via food – retention times in the
gastrointestinal tractUnderestimated total inventory of radioactive contamination:
• Inhomogeneous distributions– problems with representative sampling
• Incomplete dissolution – measuring too low concentrations
Problems with effective countermeasures• Often designed for ionic species
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
ENVIRONMENTAL IMPACT ASSESSMENT MODELS – INFO NEEDED
Link: Particle characteristics - weathering rates - ecosystem transfer - biological uptake
Assessments based on Becquerels only will suffer from large uncertainties sufficient
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Objectives “Radioactive particles in a Nordic context”- Hot II
1. Arranging a seminar at UMB with invited international speakers
• With focus on:• existing and potential sources of
radioactive particle contamination • identification, isolation and characterisation
of radioactive particles2. A review report and a database on sources and
characteristics of radioactive particles of relevance to the Nordic countries• Based on:
• literature survey• outcome of the seminar• experience within the working group
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Hot II -Participants
Norwegian University of Life Sciences (UMB), Norway• Ole Christian Lind (coordinator) & Brit Salbu
Risø National Laboratory, Denmark• Per Roos
Institute for Energy Technology, IFE, Norway• Rajdeep Singh Sidhu
Swedish Defence Research Agency, FOI, Sweden• Ulrika Nygren
Lund University, Sweden• Ylva Ranebo & Elis Holm
Radiation and Nuclear Safety Authority, STUK, Finland• Roy Pöllänen
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Joint seminar:NKS seminar on radionuclide speciation and radioactive particle studies in a Nordic context
Participants: 35 scientists from China, Denmark, Finland, Lithuania, Monaco, Norway, Spain, Sweden
Lectures: 18• Invited lecturers: 7
..\..\..\WORD\Prosjekter\NKS HOT II\Seminar april2007\Programme - NKS Seminar at UMB april2007.doc
Discussions included:• Suggestion for new methods for particle
characterisation: LA-ICP-MS, defined leaching experiments, employment of unconventional techniques
• Focus on effects: free radical induction, biomarkers (ROS, SOD)
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Joint seminar: Oscarsborg Festning NKS seminar on radionuclide speciation and radioactive particle studies in a Nordic context
Very successful meeting, especially with respect to:• Very good scientific lectures• Socially – relaxed and friendly atmosphere: good
climate for ongoing and future collaboration• Cost-effective arrangement (joint seminar)
Many scientific questions unanswered• Meetings are needed to bring further collaboration• Nordic seminars useful
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
SOURCES OF RADIOACTIVE PARTICLES
• Nuclear weapon tests (more than 2000 atm., at ground, under water, under ground tests)
• Peaceful nuclear explosions (PNE)• Aircraft accidents with conventional explosions of
nuclear weapon• Use of depleted uranium (DU) weapons• Nuclear reactor explosions and fires• Satellite and submarine accidents with nuclear
reactors• Effluents from nuclear installations• Leaching from dumped nuclear material• U-mining and tailing
Particles from all sources investigated (NKS, IAEA)
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
SOURCES OF RADIOACTIVE PARTICLESNUCLEAR EXPLOSIONS AND SAFETY TESTS
Atmospheric nuclear weapon test sites (AMAP, 1998)
Peaceful underground nuclear explosions in Russia (AMAP, 1998)Particle from Semipalatinsk test site
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Air filter samples (UMB)
Digital autoradiography (exposure 5 months) of air filter sampled in Vadsø by FFI, between 09:00, 12/11 – 15:00, 13/11 1961.
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
RADIOACTIVE PARTICLES FROM NUCLEAR EXPLOSIONS AT SEMIPALATINSK
Tel’kem (underground nuclear tests):SEM-XRMA: No U, Pu signals on the surfaceConfocal μ-SRXRF: U and Pu intensity correlated
Tel’kem I and II:U, Pu and 241Am incorporated in large grains of soil (not vitrified)Ground zero and Balapan:Vitrified particlesfrom high temperature scenarios
TEL’KEM CRATER LAKE
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
SOURCES OF RADIOACTIVE PARTICLESNuclear weapon accident at Thule
Fire in B-52
Crew bailed out – 6 of 7 survived
Aircraft with 4 unarmed thermonuclear bombs crashed on the sea ice
2 detonated conventionally
U/Pu dispersed on ice and on seabed
Re-estimated residual contamination after clean-up: ~10 TBq239Pu (~3.8 kg)
B
A
0,150,2
0,250,3
0,350,4
0,450,5
0 2 4 6 8 10μm
PuLα
/ULα
ratio
B
A
0,150,2
0,250,3
0,350,4
0,450,5
0 2 4 6 8 10μm
PuLα
/ULα
ratio
ESEM x-ray line scan reveal inhomogeneities in Thule Pu/U particle
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
SOURCES OF RADIOACTIVE PARTICLESRELEASES FROM REPROCESSING PLANTS AND PRODUCTION SITES FOR WEAPON GRADE PU
Particles observed at several sites, for example:
• Dounreay, UK – beaches closed
• Sellafield, UK - beaches• Mayak PA – Techa river• Krasnoyarsk-Jenisey river U fuel particle,
Ravenglass, Irish Sea
Remobilisation potential
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Case: Uranium mining and tailing in Central Asia –thousands of km2, affects millions of people
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
ESEM with XRMA: U inclusions in NORM particles
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Radioactive particles are released during ”all” types of severe nuclear events.
Nuclear testSemipalatinsk
Thule
XRMA
Sellafield
Aggregate from theChernobyl explosion
Corrosion productWaste in Kara Sea Krasnoyarsk U particle
Dounrey
Kuwait
The source determines the composition, the release scenarios dictate particle properties influencingthe environmental impact.
Particle composition and structureact as fingerprint – can be used toidentify the source
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Conclusions - sourcesNuclear weapon test fallout – particles at all sites, but not reported from Novaya Zemlya
Nuclear reactor accidentsWindscaleChernobylThe Sosnovyy Bor incident in 1992
Nuclear weapon accident at Thule
Technologically Enhanced Naturally Occurring RadioactiveMaterial (TENORM)
Reprocessing and Nuclear waste sitesRussian nuclear installations:
Mayak PA (Chelyabinsk-65)Siberian Chemical Combine (Tomsk-7)Krasnoyarsk Mining and Chemical Industrial Complex (Krasnoyarsk-26)
Kola Bay (STUK)Novaya Zemlya and the Kara SeaUK sites: Sellafield, Dounreay
So far, no record in the open literature on radioactive particle observations at waste sites at the Kola peninsula such as Andreyeva Bay and Grimicha
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
CONCLUSIONS – advanced methods
New advanced non-destructive tools have been developed, enabling the determination of:
• size, shape and morphology by SEM/ESEM with XRMA• elemental composition and distribution by SEM with
XRMA and μ-SRXRF• distribution of crystalline phases by μ-XRD• porosity –channels and cavities - by 3 D μ-tomography• variation in the local oxidation states of U and Pu within
particles using μ-XANES backed up by μ-XRD
• Synchrotrons at ESRF, HASYLAB, ANKA have been utilized.
• Isotope or atom ratios obtained by destructive techniques such as AMS, ICP-MS, SIMS.
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
CONCLUSIONS Following a severe nuclear event with releases of refractory elements, a major fraction of released radionuclides will most probably be associated with particles.
Particle characteristics are source-related and release-scenario dependent.
Particle characteristics: elemental composition, size distribution, porosity, crystallographic structure and oxidation state of the carrying matrices influence particle weathering, remobilization of associated radionuclides, transfer and bioavailability in ecosystems affected by particle contamination
Impact assessments for existing contaminated areas as well as for future events should be improved by implementing results from the present work.
Results from HOT II have contributed to the IAEA CRP on radioactive particles.
Salbuand Lind, R
adioactive particles in a Nordic context “H
ot”
NO
RW
EGIAN
UN
IVERSITY OF LIFE SCIEN
CES
Acknowledgement
The authors will thank our colleagues at the University of Antwerp, Belgium, professor Koen Janssens and his group, for fruitful collaboration with respect to particle characterization using synchrotron radiation based X-ray techniques