the resurgence of nuclear power - the health physics society

"With the belief that nuclear power can be safely employed,

today we see rapidly maturing efforts to build new nuclear power facilities across the globe." In Resurgence of Nuclear Power by PricewaterhouseCoopers, 2010

Health Physics SocietyAnnual Meeting • 28 June 2010

Plenary Session

"The Resurgence of Nuclear Power:Impact on the Health Physics Profession"

Reprinted from Health Physics News

The Health Physics Society acknowledges the Nuclear Energy Institute for its support in the printing of this document.

TPresident’s Message

........................................... 2Editorial

.......................................... 10Inside the Beltway

.......................................... 11Correspondence

.......................................... 12Radium Tales

.......................................... 13IRPA Stakeholder Engagement

.......................................... 15Announcements

.......................................... 17January-June 2008 Index

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Volume XXXVolume XXXVolume XXXVolume XXXVolume XXXVIVIVIVIVI Numbe Numbe Numbe Numbe Number 7 r 7 r 7 r 7 r 7 For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety July 2008 July 2008 July 2008 July 2008 July 2008

The Official Newsletter of the Health Physics Society

In This IssueIn This IssueIn This IssueIn This IssueIn This Issue

(continued on page 3)

The Resurgence of Nuclear PowerImpact on the Health Physics Profession

They say a rising tide lifts all boats.If that is so, then what might be

the near-term and far-reachingeffect on our health physicsprofessionfrom theresurgence ofnuclear powerthat somehave hailed asthe “nuclearrenaissance?”

Considerfor a momentthat the scopeand scale of nuclear power encom-passes much more than just theoperation of commercial nuclearreactors to generate electricity—even from the focused perspec-tive of health physics. It includesthe exploration and mining foruranium and thorium; the pro-cessing and milling of extractedore; the enrichment and fabrica-tion of nuclear fuel; the licensing,construction, start-up, operation,and ultimate decommissioning ofnuclear power plants; the analy-sis, planning, and preparednessfor the possibility of an accident;the packaging, transport, anddisposal of low-level radioactivewaste; and the management ofused nuclear fuel, which mightinclude its own extensive realm of

Ralph Andersen, CHPHealth Physics News Associate Editor

recycling, reprocessing, andnonproliferation.

Consider also that a nuclearrenaissance will need a revitalized

infrastructure,includingacademicinstitutions totrain andeducate a newworkforce andconduct basicand appliedresearch, aswell as indus-

tries to develop, produce, anddeliver new radiation protectioninstrumentation and equipment,radioactive calibration and testsources, and ionizing and nonioniz-ing radiation technologies for qualitycontrol in facility construction,nuclear system component manu-facturing, and plant equipmentmaintenance.

In short, the effect of a resur-gence of nuclear power in the areaof health physics will be pervasiveand profound.

Over the next year, HealthPhysics News intends to publish aseries of articles that will explore thevarious sectors of nuclear energythat, while unique and relativelyunfamiliar to our membership at

33333 Health Physics News • July 2008

The Resurgence of Nuclear Power

(continued from page 1)

large, share the basic science, principles, and methodsthat are common throughout our profession. To inaugu-rate the series, this article provides a general overview ofnuclear power generation—where it is today and whereit’s headed tomorrow, environmental considerations, andsome challenges and opportunities related to healthphysics. Future articles will trace each step of thenuclear power fuel cycle in more detail from its extrac-tion from the earth to its ultimate disposition in the earthagain.

Nuclear Power—Today and TomorrowSources of Electricity in the United States

Today, there are 104 nuclear power plants generating20 percent of the nation’s electricity at 65 sites in 31states (Figure 1). These plants provide electricity at alow cost with a high level of reliability. In 2007, averageelectricity production costs at nuclear power plants were1.76 cents per kilowatt-hour (Figure 2), and plant

capacity factors averaged 92 percent. Capacity factor isthe amount of electricity actually generated by a plant ina year divided by the total amount of electricity thatcould have been generated if the plant had operated 24hours a day throughout the entire year.

Geographic Location of Potential and Existing Nuclear PlantsGeographic Location of Potential and Existing Nuclear PlantsGeographic Location of Potential and Existing Nuclear PlantsGeographic Location of Potential and Existing Nuclear PlantsGeographic Location of Potential and Existing Nuclear Plants

Figure 1

Figure 2

Health Physics News • July 2008 44444

Other sources of electrical generation in the UnitedStates include fossil fuels, hydropower, and renewableand other energy sources. Nearly half (49 percent) of theelectricity generated in the United States comes fromcoal, which is also a low-cost power source at 2.47cents per kilowatt-hour. The average capacity factor forcoal-fired plants (71 percent) is second among electricalpower sources. The second largest source of electricitygeneration is natural gas, providing 22 percent of thetotal generation. Natural gas prices have been volatileover the past decade and production costs in 2007 were6.78 cents per kilowatt-hour. Oil provides less than 2percent of electrical generation due mainly to the highproduction costs (10.26 cents per kilowatt hour in 2007)and extreme volatility in the price of oil.

Hydropower facilities provide 6 percent of electricalgeneration with low average capacity factors (28percent). Renewable and other energy sources provideabout 3 percent of electrical generation with variedaverage capacity factors—including wind (30 percent),solar (20 percent), geothermal (75 percent), and biomass(71 percent). To date, these sources of electrical genera-tion have not formed a significant contribution tobaseload production due to limitations in regard toreliability, location, and/or power density (i.e., theamount of power that can be generated with a facility’s“footprint.”)

License RenewalNuclear power plants were initially granted licenses to

operate for 40 years, based on the level of engineeringanalysis and limited operating experience at that time.Since then, we have gained several thousand reactor-years of experience and have developed much moreinformative and robusttechniques to evaluate thesafety of the plants (e.g.,probabilistic risk assessment).In the 1990s, nuclear powerplants began submittingapplications to extend thelicensed period for operationfor an additional 20 years.

The Nuclear RegulatoryCommission (NRC) reviewprocess, termed licenserenewal, has been continuallyrefined with experience sothat today nearly half of theoperating reactors (48 plants)have received approval tooperate for a total of 60 years.As shown in Figure 3, the

majority of the remaining plants either have a licenserenewal application under review at this time or haveformally announced their intent to prepare an applicationat the appropriate time (typically about 10 years prior toexpiration of the original license). The remainder (nineplants) have not yet announced their intention becausethey still have a significant period of time remaining ontheir operating licenses and it would be premature toproject and assess regional energy needs that far in thefuture with the associated larger uncertainties.

The operating horizon for the current generation ofnuclear power plants in the United States now extends to2030 and beyond. Scientific and engineering researchhas already begun to assess the possibility of of extend-ing nuclear power plant operating licenses by another 20years (i.e., a total 80-year operating lifetime).

New Nuclear Power PlantsOver the past 10 years, there has been a rapidly

growing interest in building new nuclear power plants inthe United States. This interest has been driven byseveral factors.

First, there is an increasing need for new baseloadenergy to address not only the increased demand forelectricity, but also to offset the retirement of olderelectricity-generating assets. In the near term, the needfor new generating capacity is especially acute in theNortheast, mid-Atlantic, Southeast, South, and Texas.Overall across the nation, the demand for electricity isexpected to increase by as much as 25 percent by theyear 2030.

Second, increasing concerns about the environment,especially related to climate change, have raised thelikelihood of imposing some form of constraints on

carbon emissions, whichespecially challenges the useof fossil fuels as the source ofnew electricity production.This challenge is compoundedby the continued volatility innatural gas prices and theskyrocketing costs of oil. Third, renewable energysources are not likely to beable to provide the dramaticincrease in reliable, baseloadenergy necessary to meet asustained increase in demandfor electricity. There is little orno opportunity for developingnew large-scale hydropowerinstallations. While it isessential that continuedFigure 3


emphasis and support be provided for developing windand solar power, the inherent limitations on reliability andsiting that exist today cause experts to predict that theseenergy sources cannot deliver more than a small percent-age of the new power thatwill be needed by 2030.Although aggressive energyconservation and improvedefficiency in energy use canmake a significant inroadinto new energy demand,this is not a singular solu-tion.

Finally, the excellentsafety record of the nuclearindustry, high levels ofreliability, and low produc-tion costs, along with thelack of greenhouse gasemissions during operation,make nuclear power a muchmore accepted and desiredsource of energy for the future. However, new nucleargenerating capacity alone is also not sufficient to be “thesolution,” even under the most optimum of scenarios fornew build.

The energy policy for an energy-secure nation in thefuture that is being advocated by the nuclear energyindustry, as well as many others in the energy sector,includes the following:• Implement energy efficiency and conservation in allphases of electricity generation and use.• Employ renewable energy sources to the fullest extentpossible.• Maintain an energy portfolio with diverse energysources.• Rely on nuclear power as a proven large-scale,emission-free energy source for baseload generation.

The Nuclear Energy Future Is NowSeventeen companies and consortia are submitting

license applications to the NRC to construct and operateas many as 31 new nuclear power plants in the UnitedStates. Five applications were submitted in 2007 and 11-15 more are expected by the end of 2008. Also, threenew applications have been submitted to the NRC thisyear for certification of new reactor designs, in additionto the two that have already been certified.

The realistic expectations of industry experts are thatthe first new nuclear power plant will begin commercialoperation in 2017, with a potential for up to 15-20 newplants coming online in the years shortly thereafter.

Environmental Considerationsfor Nuclear Power

One of the strongest arguments for continuing tooperate the current fleet of nuclear power plants and to

build new plants is the vitalrole of nuclear power inpreventing greenhouse gasemissions, particularlycarbon, during the produc-tion of electricity. Nuclearpower accounts for morethan 70 percent amongU.S. electricity sourcesthat do not emit green-house gases (Figure 4).The remainder is ac-counted for primarily byhydropower (22 percent),along with an increasingfraction contributed bywind, geothermal, andsolar power.

For perspective, in 2006 U.S. nuclear power plantsoffset nearly 700 million metric tons of CO2, ascalculated from the data of the U.S. EnvironmentalProtection Agency (EPA). Also using EPA data, thisamount of CO2 avoided is equivalent to the total CO2emitted by the 136 million passenger cars driven onU.S. roadways. However, there are some who make the claim thatnuclear energy produces significant levels of emissionsof greenhouse gases and other pollutants if you considerthe entire nuclear life cycle, including mining and milling,fuel fabrication, construction, operation, and ultimatedecommissioning. The facts do not bear this out. A life-cycle analysis of the emissions produced by variouselectricity-generating sources (see Table 1 on page 6)shows that nuclear and hydropower represent thelowest-emitting sources of electricity generation,followed by wind, solar, and biomass.

Radiation Protection at Nuclear Power PlantsRadiation protection at nuclear power plants has

proven to be challenging, interesting, and fulfilling for the2,000 health physicists and technicians who work at 104operating nuclear power plants in the United States.These radiation protection professionals oversee radiationsafety around the clock for more than 100,000 moni-tored workers who receive measurable occupationalradiation dose during operation, refueling, and mainte-nance of the plants, as well as for the people who livearound the plants and the environment. The radiationprotection staff also continuously train and participate in

Figure 4

U.S. Electricity Sources Which Do NotU.S. Electricity Sources Which Do NotU.S. Electricity Sources Which Do NotU.S. Electricity Sources Which Do NotU.S. Electricity Sources Which Do Not

Emit Greenhouse Gases (2007)Emit Greenhouse Gases (2007)Emit Greenhouse Gases (2007)Emit Greenhouse Gases (2007)Emit Greenhouse Gases (2007)


exercises and drills to beprepared to address all kindsof contingencies, up to andincluding postulated nuclearaccidents. Radiation protectionorganizations at nuclearpower plants include healthphysicists, technicians, andspecialists who are exten-sively trained and qualified tocover a wide range of dutiesand responsibilities, includingradiation monitoring andsurveillance, radiationprotection job coverage, aslow as reasonably achievable(ALARA) planning andradiological engineering,internal and external dosim-etry, instrument calibrationand maintenance, respiratoryprotection, decontamination,radioactive material inven-tory and control, radiologicalsampling and analysis,radiological effluent monitor-ing and control, environmen-tal monitoring, radioactivewaste packaging and ship-ment, and emergencypreparedness and response.

The types of nuclearpower plant workers, andthe diverse job functions thatthey perform, cover a widerange of disciplines, includ-ing reactor operations,nuclear, mechanical, electri-cal, and civil engineering,mechanical and electricalmaintenance, instrumentationand control (I&C), chemis-try, radioactive wastemanagement, radiography,in-service inspection (ISI),nondestructive examination(NDE), security, training,and quality assurance, aswell as skilled craft applica-tions, such as welding,boiler-making, pipefitting, scaffolding, insulating, etc. Plantradiation protection staff must become sufficiently knowl-

edgeable across all of theseareas to be able to fullyunderstand the radiologicalprotection aspects related tothe work and to provideeffective radiation safetysupport. The nuclear powerindustry work ethic andculture is founded onlearning from experience andcontinuously finding ways toimprove performance—especially in regard toradiation safety. Every planthas a well-developed pro-gram for maintainingradiation exposures ALARAthat involves every level ofplant workers, radiationprotection staff, site manage-ment, and company seniormanagement and executives.Work to be performed in aradiologically significant areais planned, staged, andcarried out in a manner thatwill assure a high degree ofradiation and industrial safetyand minimize radiationexposures. Followingcompletion of the work,post-job reviews are con-ducted with the workers toidentify lessons learned andplan further improvementsfor the next time the work isscheduled. The dose-reduction resultsthat have been achievedthrough this process ofcontinuous improvementhave been dramatic. In thepast 25 years, the averageannual collective dose perreactor was reduced from774 person-rem to 106person-rem, a seven-folddecrease (Figure 5). At thesame time, average annualmeasurable dose per worker

was reduced from 660 mrem to 140 mrem, more thana four-fold decrease (Figure 6). In the area of indus-

Figure 5

Figure 6

Table 1

Emissions Produced byEmissions Produced byEmissions Produced byEmissions Produced byEmissions Produced by1 Kilowatt-Hour of Electricity1 Kilowatt-Hour of Electricity1 Kilowatt-Hour of Electricity1 Kilowatt-Hour of Electricity1 Kilowatt-Hour of ElectricityBased on Life-Cycle AnalysisBased on Life-Cycle AnalysisBased on Life-Cycle AnalysisBased on Life-Cycle AnalysisBased on Life-Cycle Analysis


trial safety, the results havebeen equally dramatic, with athree-fold decrease achievedin the industrial safetyaccident incidence rate overthe 10-year period from 1997to 2006, from 0.38 per200,000 worker hours to0.12 (Figure 7). For perspec-tive, the incidence rate foroffice workers in 2006 (1.7per 200,000 worker hours)was more than 10 times thatfor nuclear power plantworkers.

Future Challenges inRadiation Protection In consideration of theextended operating period ofthe current fleet of nuclearpower plants and in anticipa-tion of building and operatingnew plants, the nuclearpower industry has formed aworking group of companyexecutives and radiationprotection program managersto develop an industrystrategy to address futurechallenges in radiationprotection. The name givento the effort is “RP 2020,” tocharacterize the planningtime frame through the year2020 that will encompass the period in which the firstwave of new nuclear power plants is expected tocommence operation.

As an initial part of the effort, the working group isbuilding a list of future challenges that should beaddressed within RP 2020. While this preliminary listwas derived from a nuclear power plant focus, it isapparent that the challenges are likely to be similarlyapplicable to many sectors within the health physicsprofession. Three of the challenges are highlightedbelow, including workforce, standards, and publicperception about radiation.

WorkforceThe most significant challenge that has been identified

is in regard to developing the workforce of healthphysicists and technicians who will be needed for thenext 70+ years at commercial nuclear power plants,

which encompasses at leastthree more generations ofnew radiation protectionprofessionals. The currentsituation is reflected in Figure8, which shows the distribu-tion of the current radiationprotection workforce by age.This distribution is beingtracked by the NuclearEnergy Institute in a biennialsurvey that obtains informa-tion about the entire nuclearpower workforce, not justradiation protection staff. The issue is simple andinescapable: half of thenuclear power radiationprotection workforce is 50years old or older and islikely to retire or leave theindustry for other reasonsover the next 10 years. At thesame time, the entry rate ofnew radiation protection staffinto the industry is on adeclining trend, such thatonly about 10 percent of theworkforce is under 40 yearsold. This means that thenuclear power industry willeither need to develop andbring into the workplacemore than 1,000 new healthphysicists and technicans

over the next 10 years, or it will need to substantiallychange how radiation protection is conducted at nuclearpower plants in the future, so as not to need as manystaff, or both.

In recognition that this challenge extends across theentire spectrum of the health physics profession, thenuclear power industry is partnered with other privateand public sectors and the Health Physics Society todevelop common solutions. This issue has been thesubject of several articles in Health Physics News in thepast, and a description of the current scale and scope ofthis effort is best left to an update in a future article onthis topic.

StandardsIn December 2007, the International Commission on

Radiological Protection (ICRP) issued Publication 103,containing its new set of recommendations. In turn, the

Figure 7

Figure 8


International Atomic Energy Agency (IAEA) is updatingits basic safety standards for radiation protection(expected to be issued in 2009) to reflect the new ICRPrecommendations. Together, these documents will formthe basis for the next generation of radiation protectionregulations around the world.

Globally, countries and industries utilizing nuclear andradiation technologies are already evaluating how andwhen they might change regulations to incorporate thenew ICRP recommendations and IAEA standards. In theUnited States, for example, the NRC staff is preparing apaper to be submitted for Commission review in Decem-ber 2008 that will include various options for pursuingrulemaking to update the agency’s regulations.

Such changes will be evolutionary for most coun-tries—in which radiation protection regulations arealready based on ICRP Publication 60. In the UnitedStates, however, the federal framework for radiationprotection is generally based on ICRP Publication 26 foroccupational radiation protection and on ICRP Publica-tion 2 for public radiation protection. Therefore, achange to regulations will entail leaping ahead by two orthree generations, rather then transitioning from onegeneration to the next. This will be particularly challeng-ing in regard to dose standards and methodology, not tomention the long-standing differences in the usage ofunits of dose and activity.

The nuclear industry working group is evaluating thescope of possible changes to NRC regulations with theintent of providing input for consideration by NRC staffin developing its options paper for the Commission.

Radiation PerceptionU.S. radiation protection regulations and health physics

practices (e.g., ALARA) are based on the assumptionthat radiation health effects are linearly proportional toradiation dose without a threshold (LNT assumption).Employing that basis, regulatory agencies and licenseeshave assessed the possibility of public health and safetyimpacts from gaseous and liquid effluent releases fromnuclear power plants as exceedingly small. In fact, thecalculated annual maximum dose to a person living nextto a nuclear power plant is a millirem or less and theaverage dose to people living within 50 miles of the plantis calculated as less than 1/100th of a millirem. Theseassessments are backed up by extensive monitoring andsampling results that are tabulated and submitted annuallyto the NRC in publicly available reports.

Nevertheless, groups continue to call on the NRC andother agencies to revise their “inadequate” regulations toreflect the LNT (which they already do) and hold upstudies that purport to show health effects amongpopulations living around nuclear power plants. Even

though public health departments and regulatory agenciesrepeatedly discredit them, the claims are finding a newplatform in license renewal and new plant hearings andare being given ample newspaper coverage and air timein the name of balanced reporting and fairness. It is notsurprising that public opinion polls show a modest, butsustained, concern among the general public aboutradiation from nuclear power plants, as well as fromother human-made sources.

The health physics community across all sectors istaking on this challenge, not by perpetuating thedebate between proponents and opponents, but byimproving the transparency of our radiation safetyprograms and developing clear, accessible informa-tion. This is aimed at providing resources for peopleto become more informed on their own and to assessfor themselves whether they should be concernedabout various claims. A recent example of this newapproach is the HPS radiation primer, which can befound at www.radiationanswers.org.

Going ForwardThe nuclear power industry has defined the mission of

RP 2020 as one that will “reshape radiological protectionat nuclear power plants.” Simply improving the existingprograms and processes will ultimately fall short of whatis needed to address the challenges described above andothers. Examples of strategies that are being developedto help accomplish this include:• Reform, not just update, radiation protection regula-tions to become more focused on results, rather thanprocess.• Significantly reduce radiation fields that are accessedby workers in the plant.• Improve technologies’ utilization to facilitate remotemonitoring and worker self-protection.• Redefine the roles, skills, and qualifications forradiation protection staff.• Improve worker and public access to radiationprotection information.• Standardize radiation protection practices.

The nuclear power industry strategy for radiationprotection, RP 2020, is scheduled to be completed in2008.

Public Support for Nuclear EnergyPublic support for more nuclear energy has been

increasing over the past decade, according to nationalsurveys. Those surveys show that support is at an all-time high, with 83 percent of Americans in favor ofrenewing the licenses of existing plants and 66 percentaccepting new reactors being built at the nearest existing


Editor’s Note: We will be continuing this series on the resurgence of nuclear power and the impact on our healthphysics profession in upcoming issues of Health Physics News. We welcome experts in the various sectors of nuclearenergy to write articles covering the areas discussed on the first page of this story. Contact me at [email protected] or507-362-4176 for information about content and deadlines.

nuclear plant (Figure 9). Issues identified by thosesurveyed as important to their support for nuclear energyinclude the economy, climate change, energy security,and air pollution.

A survey issued on 6 June 2008 by Zogby Internationalfinds that 67 percent of Americans favor building newnuclear power plants in the United States. Respondentsin the survey also indicated their preference for theconstruction of a nuclear power plant in their communityover a natural gas, a coal, or an oil plant.

In SummaryThe resurgence in nuclear power holds great promise

in terms of economic growth, energy security, andenvironmental protection. But the attendant challengesare also great. Change is sure to come. The question forus is whether we will envision and commit ourselves toachieving a future that we want, or simply let the futurehappen.

Ralph and granddaughter, three-year-old Sylvia Rose Wines Photo by Marlene Andersen

Ralph Andersen, CHP, isthe director of radiationsafety and low-levelwaste management at theNuclear Energy Institute(NEI) in Washington, DC.He represents the nuclearenergy industry to theCongress, the Administra-tion, federal agencies, andother national and interna-tional organizations ongeneric nuclear energypolicy matters related toradiological protection,low-level radioactive wastemanagement, and environ-mental protection.

Before joining NEI in 1992, Ralph worked for 20years in radiation protection, holding such positionsas radiation protection manager at the Detroit EdisonCompany’s Fermi 2 nuclear power plant, radiation

safety officer and lecturerat the University ofColorado, and principalresearcher and associateradiation safety officer atthe University of MarylandMedical Center. Ralph is a member ofthe Health Physics Society(HPS) Government andSociety Relations Com-mittee and an associateeditor for Health PhysicsNews. He received his BAdegree from the Univer-sity of Maryland and tookgraduate courses in theDepartment of Radiation

Biology and Radiology at Colorado State Univer-sity. Ralph’s favorite pastime is going on adventureswith his wife, Marlene, and granddaughter, Sylvia.

Figure 9

99999 Health Physics News • September 2008

IntroductionUranium recovery encompasses conventional uranium

mining and milling aswell as in situ recoverytechniques (Figure 1)and the recovery ofuranium as a byproductfrom other processes,such as phosphoricacid production.

Concurrent with therecognition that nuclear-generated electricitymust play an increasingrole in worldwideenergy supply and inconsideration of the newnuclear power plantsordered or planned, thedemand for uraniumneeded to fuel thesereactors has alreadyoutpaced supplies.Accordingly, the price ofuranium (typicallyexpressed as $ per poundU3O8 equivalent) hasincreased significantlyover the last two years.As a result, numerousnew and reconstituteduranium recoveryprojects are beingdeveloped in the UnitedStates and in othercountries that possessconsiderable uranium ore


Impact on the Health Physics Profession


This is the second in a series of articles in Health Physics News that will explore the various sectors of nuclearpower that, while unique and relatively unfamiliar to our membership at large, share the basic science, principles,

and methods that are common throughout our profession. The first installment (Health Physics News, July 2008),presented a general overview of nuclear power generation—where it is today and where it’s headed tomorrow,environmental considerations, and some challenges and opportunities related to health physics. This article focuses onthe front end of the nuclear fuel cycle, i.e., the uranium recovery industry.

reserves (e.g., Canada, Australia, Kazykstan,Mongolia, Namibia, and others). This imbalance between supply and demand is

depicted in Figure 2.Historical uranium pricesare shown in Figure 3(next page), includingthe recent significantprice increase as a directresult of the supply/demand imbalance. Itshould be noted that inthe United States, ourcurrent reactor fleet of104 operating units,which generate 20percent of our base-loadelectricity, requiresapproximately 55 millionpounds of U3O8 per year,but only about 4-5million pounds per year

is produced domestically.That is, over 90 percentof our current demand,ignoring anticipatedincrease in requirements inthe near future as newplants come online, mustcome from foreignsources. Domesticuranium production overthe last 10 years reached alow of about two millionpounds in 2003 and hasbeen increasing steadilysince then.

The Uranium Recovery IndustrySteven H.Brown, CHP

Figure 2. U3O8 production versus demandwww.uraniumproducersamerica.com/supply.html

Figure 1. Uranium fuel cycle

Health Physics News • September 2008 1010101010

History of Uranium Recovery in the United States In the United States, the mining of ore that containsuranium goes back to the early part of the 20th century.At that time the interest was not in uranium per se, but inother minerals associated with it, namely vanadium andradium. Interest in uranium began in earnest in the yearsimmediately following World War II with the passage bythe U.S. Congress of the McMahon Act (more commonlyknown as the Atomic Energy Act [AEA], signed byPresident Truman in August 1946), which created theUnited States Atomic Energy Commission (AEC) andestablished the U.S. government as the only buyer ofuranium (for the nuclear weapons program). Thegovernment’s uranium ore procurement program sentthousands of prospectors crawling over the “ColoradoPlateau” (the four corners area of Utah, New Mexico,Arizona, and Colorado). The AEC developed publications toassist prospectors in this regard (Figure 4). This ore wasprocessed at a number of sites—collectively known as the“MED (Manhatten Engineering District) Sites”—andremediated decades later under the Formerly Utilized SitesRemedial Action programs still ongoing today. AECincentives ceased in 1962, and mining and milling opera-tions on a much larger scale than those early efforts were

established by private companies.As the commercial nuclear power industry developed

in the late 1960s and early 1970s, the federal govern-ment was no longer the exclusive buyer of domesticallyproduced uranium. U.S. production and uranium pricespeaked in the early 1980s. Shortly thereafter, domesticdemand for uranium ore declined as the commercialnuclear power industry fell far short of its expectedgrowth and in response to, and low cost of, muchhigher-grade Canadian and Australian deposits that beganto dominate world markets. Planning and construction ofnew U.S. commercial nuclear power plants came to a haltand the domestic price of uranium dropped dramati-cally, and the nation faced an oversupply of uranium

despite the fact that demand remained about eventhrough 2003.

As a result of the market conditions described above,the uranium recovery industry will benefit directly fromthe “nuclear renaissance” of today and into the nearfuture. The U.S. Nuclear Regulatory Commission (NRC)Uranium Recovery Branch estimates that over the nextfew years, it expects to receive over 30 source materiallicense applications for new and/or upgraded uraniumrecovery facilities (Camper 2008—see Table 1). Similarnew project development is also taking place in thehistorical uranium recovery districts in NRC AgreementStates (e.g., Texas and Colorado).

Overview of Conventional UraniumMining Techniques Conventional mining generally refers to open-pit andunderground mining. Open-pit mining is employed forore deposits that are located at or near the surface, whileunderground mining is used to extract ore, typically ofhigher grade (concentration of uranium in the oreexpressed as weight percent or ppm), from deeperdeposits. Conventional uranium mines are not regulatedunder the AEA since the raw ore is not considered“source material”1 under the Act and therefore is not a“licensed material.” The health and safety aspects ofFigure 4. AEC uranium prospecting booklets

Figure 3. Source: 48-68 U.S./AEC, 69-86 Nuexco EV, 87-Present U3O8 Price

*In Situ RecoveryTable 1. New source material licensing actions anticipated byNRC in next few years


conventional uranium mines areregulated at the federal level bythe Mine Safety and HealthAdministration of the U.S.Department of Labor and byrespective state agencies withresponsibility for health, safety,and environmental protectionassociated with mining.

Open-pit mining involves thesurface removal of soil androck overburden and extrac-tion of ore. Open-pit mines arebroad, open excavations thatnarrow toward the bottom andare generally used for shallowore deposits. The maximumdepth of open-pit mining in theUnited States is usually about150 meters. Lower-grade ore can be recovered in open-pitmining, since costs are generally lower compared tounderground mining. In open-pit mining, topsoil is removedand often stockpiled for later site reclamation (i.e., restora-tion). Overburden is removed using scrapers, mechanicalshovels, trucks, and loaders. In some cases, the overbur-den may be ripped or blasted free for removal. Once theuranium ore-bearing horizon is reached, the ore is ex-tracted. The extracted ore is stockpiled at the surface ortrucked directly to a conventional uranium mill (see below)for processing into the U3O8 product (referred to as“yellowcake” due to its typical color).

Deeper uranium ore deposits require undergroundmining in which declines or shafts are excavated and/ordrilled from the surface to access the ore-bearingstrata at depth. These deeper deposits may requireone or more vertical concrete-lined shafts or declineslarge enough for motorized vehicles to reach the ore.Stopes (an underground excavation from which orewill be removed in a seriesof steps) reaching out fromthe main shaft provideaccess to the ore. Ore andwaste rock generatedduring mining are usuallyremoved through shafts viaelevators or carried to thesurface in trucks alongdeclines. As with open pits,the extracted ore is stock-piled at the surface andsubsequently transporteddirectly to a conventionaluranium mill.

Conventional Uranium MillsUranium mills (and in situ recovery facilities [ISRs],

see page 12) are “licensed facilities” since they producesource material as defined under the AEA. Accordingly,licensing requirements and management of uranium millsare defined in NRC’s 10 CFR 40, Domestic Licensing ofSource Material, and commensurate requirements ofagreement state regulations. The generalized conven-tional uranium milling process is depicted in Figure 5,and an aerial view showing the “footprint” of a conven-tional mill and associated tailings (radioactive waste)impoundment is shown in Figure 6. As shown in Figure 5, the initial step in conventionalmilling involves crushing and grinding of the raw ore toproduce uniformly sized particles. Various mechanicalmills grind the rock to further reduce the size of the ore.After the ore is ground and is put in the form of a slurry,it is then pumped to a series of tanks for leaching,either in an acid- or alkaline-based process. The

uranium liquor is separatedfrom residual solids andthen dissolved into asolvent. These solids arethe “uranium mill tailings”which must be managed inlarge surface impoundmentsas the major radioactivewaste stream of a conven-tional mill. The uranium isthen recovered (stripped)from the solvent-basedliquor. The final stepsconsist of precipitation toproduce yellowcake,

Figure 5. Generalized conventional uranium milling processU.S. DOE Energy Information Administration

Figure 6. Aerial view—conventional uranium mill complexPhoto courtesy Cotter Corporation


followed by drying and packaging of the final U3O8product.

A commercial-scale conventional mill processes on theorder of 1,000 tons or more of ore per day and producesone to two million pounds per year of U3O8. Over 95percent of the ore mass constitutes radioactive wastes(tailings) and must be permanently impounded at or nearthe mill site in a highly engineered landfill (“tailings pile orpond”). This material is referred to as “11e.(2)byproduct material” after the AEA paragraph whichlegally defines it. Radiologically, this material contains 99percent of the uranium series radionuclides whichoccurred in secular equilibrium with the 238U parent in theore body, minus most of the uranium. For an ore gradeof a few tenths of a percentage uranium, the tailingswould contain an order of magnitude of a few 10s to afew 100s Bq/g of each daughter in equilibrium.

In Situ Recovery FacilitiesISRs (also referred to as in situ leach or uranium

solution mining) are rapidly becoming a preferredmethod around the world for uranium recovery. This isprimarily because of lower capital costs, fewer man-power requirements for operations, smaller land-usefootprints, and environmental advantages over conven-tional mines and mills. However, applicability of thistechnology is generally limited to very specific geologi-cal, hydrological, and geochemical conditions. Uraniumdeposits typically amenable to in situ recovery are usuallyassociated with relatively shallow aquifers, about 30-150meters subsurface, confined by nonporous shale ormudstone layers. The uranium was transported to theselocations over geologic time as soluble anionic com-plexes by the natural movement of oxygenated ground-water. Deposition occurred in areas where the ground-water conditions changed from oxidizing to reducing,producing what is known as a “roll front deposit.”

Accordingly, ISRs are typically used for recovery ofuranium at ore grades below that associated withconventional mining (open pits or underground). Typicaluranium ore grades associated with ISR roll-frontdeposits are about 0.1 percent-0.2 percent (1,000-2,000ppm uranium in the ore). ISRs, like conventional mills,are considered source material facilities under the AEAand therefore must be licensed and operated as suchunder NRC (e.g., 10 CFR 40) or commensurate agree-ment state regulations and requirements.

ISR processes in the United States typically involve thecirculation of groundwater, fortified with oxidizing(typically gaseous oxygen) and complexing (e.g., carbondioxide) agents into an ore body (referred to as “thelixiviant”), solubilizing the uranium in situ, and thenpumping the solutions to the surface where they are fed

to a processing plant (very similar to a conventional mill,without the need for ore crushing, grinding, and leaching).The uranium dissolved in solution returning from under-ground is first concentrated in an ion exchange circuit,stripped from the ion exchange resin via an elution processand then precipitated into yellowcake, dewatered, dried,and packaged as the final U3O8 product in an identicalmanner as in conventional mills. Figure 7 shows thebasic approach to in situ uranium recovery. Figure 8shows the footprint in an aerial view of a modern ISR.

Since ISRs do not process large volumes of ore(rock), as do conventional mills, conventional-typeuranium mill tailings are not generated by these pro-cesses. However, ISRs do generate relatively smallvolumes of 11e.(2) byproduct material related to the needto remove calcium compounds from the process tomaintain formation and system permeability and removeimpurities. Radium follows the calcium chemistrythrough the process. Measurements made in the 1970sand early 1980s indicated that 5-15 percent of equilibrium

Figure 7. Basic approach to in situ uranium recovery

Figure 8. Aerial view—in situ uranium facilityPhoto courtesy Wyoming Mining Association


226Ra in the host formation ends up in this material (NMA2007, Brown 1982). This material must be shipped off-siteto a licensed uranium mill tailings impoundment or otherlicensed disposal facility authorized to accept it. Addition-ally, due to the need to extract several percent greatervolume of solutions for hydrological control than is actuallyreinjected in the well fields (“over recovery”), largevolumes of solutions must be impounded and managed atthe surface. In modern designs, these fluids are disposedof via irrigation and/or injected in permitted deep-welldisposal systems following treatment.

Another special consideration associated with ISRsthat has health physics implications is the manner inwhich 222Rn gas is evolved by the process. At conven-tional mills, the “radon source term” is almost exclu-sively the result of the natural decay of 226Ra in ore binsand the tailings impoundment. At ISRs, it was observedthat more than 90 percent of the radon source termresults from the dynamic release of radon dissolved inthe lixiviant solution as it returns from the undergroundenvironment (Brown and Smith 1981). It appears thatthe temperatures and pressures in situ enhance solubilityof radon, and much of the dissolved gas is releasedwhen the solutions are first exposed to atmosphericconditions. If this is inside the plant, local exhaustsystems deployed at point(s) of release are often requiredto remove the radon from the work environment,thereby minimizing opportunity for progeny in growth.When inhaled, it is the particulate progeny, not the radongas itself, that produce the majority of the pulmonary dose.

Additional Uranium Recovery Technologies that MayBe Revisited

In the 1970s and into the 1980s, uranium was alsorecovered as a byproduct of copper and phosphateproduction. I was the radiation safety officer for a plantthat was colocated at the world’s largest open-pit coppermine, near Salt Lake City, Utah. Our uranium plantreceived a portion of the copper recovery circuit liquorand, through ion exchange and subsequent traditionaluranium milling processes as described above, produced150,000-200,000 pounds per year of yellowcake.Similarly, I had corporate radiation protection oversightresponsibility for one of the several uranium recoveryfacilities in the phosphate lands of west central Florida.This facility received a portion of the phosphoric acidproduction plant stream and, through traditional uraniummilling processes, also produced a similar rate ofyellowcake. Regarding uranium’s well-known occur-rence in phosphate rocks, it seems reasonable to assumethat uranium companies are again or shortly will be re-evaluating the potential uranium reserves inherent in thismaterial and the associated economic viability of recovery.

Environmental Monitoring at Uranium Mills and ISRsComprehensive environmental monitoring programs

must be conducted at uranium recovery facilities to (1)establish the preoperational radiological baseline againstwhich potential future impacts can be assessed and (2)demonstrate compliance during operations to publicexposure standards (e.g., 1mSv/y per 10 CFR 20.1301)and to ensure effluent releases are maintained ALARA.These programs are typically performed in accordancewith NRC Regulatory Guide 4.14 (NRC 1980).

Uranium and, therefore, its progeny are naturallyoccurring, and levels in environmental media can varyconsiderably from place to place depending on localgeology, hydrology, and geochemistry. Accordingly,measurements are made of direct radiation (cosmic plusterrestrial) and of uranium-series radionuclides in air(long-lived alpha-emitting particulates and radon gas), insurface and groundwater, and in soil, vegetation, andmeat, milk, and fish as may be applicable at a givenlocale. Key elements of the preoperational baselineprogram are continued during plant operations and alsotypically include effluent monitoring (radionuclideparticulates and radon releases from ventilation systemsand yellowcake dryer stacks).

Operational Health Physics Programs at UraniumRecovery Facilities

Uranium Mines: The environment undergroundpotentially exposes workers to two primary sources: (1)internal exposure from inhalation of 222Rn and its short-lived progeny in breathing air (the “radon daughters,”218Po, 214Bi, 214Pb, and 214Po) and (2) external exposurefrom close proximity to higher-grade uranium ore.Needless to say, ventilation and diligent air samplingprograms are critical in maintaining internal exposureALARA and, in higher-grade mines, occupancy times insome areas underground often must be managed andcontrolled. As indicated previously, worker health andsafety in mines in the United States is regulated by theMine Safety and Health Administration (MSHA). MSHAregulations currently require documentation of internalexposure (typically in working level2 months [WLM] ofradon daughter exposure relative to a standard of 4WLM/y) and external exposure relative to a 5 rem/ystandard. However, at the present time, MSHA does notrequire conversion of WLM of exposure to a committedeffective dose equivalent (CEDE) nor the addition ofinternal and external exposure into an expression of thetotal effective dose equivalent (TEDE). At open-pitmines, internal exposure is usually minimized sinceexcavation is in the open air and dust suppressiontechnology is applied typical of large civil engineeringconstruction projects.


Uranium Mills and ISRs: Operational health physicsprograms in conventional mills and ISRs are very similarand are generally consistent with any nuclear materialfacility that produces standard industrial uraniumcompounds of natural enrichment3 and include:• Airborne monitoring for long-lived alpha emitters(uranium, thorium), primarily in ore crushing, drying,and packaging areas including combinations of grabsampling and breathing zone sampling.• Radioactive material area ingress/egress controlprograms and surface-area contamination surveillanceand control throughout plant areas.• Respiratory protection programs if necessary, typicallyonly necessary in ore crushing, product drying, andpackaging areas.• Bioassay programs appropriate for the uraniumproducts to which employees are potentially exposed. Itmust be noted that product-specific solubility character-istics can have metabolic implications for bioassay (NRC1986; NRC 1988; Eidson and Mewhinney 1980). Highersolubility results in faster pulmonary clearance and,therefore, less pulmonary dose and vice versa. Typically,only urinalysis is performed with in vivo lung counting inresponse to confirmed intakes above specified actionlevels.4

• Work control and training via formalized procedures.• Internal audit and quality-control programs to ensureexecution of safe work practices, regulatory compliance,and ALARA.• Airborne monitoring for radon and progeny as dictatedby specifics of facility design.• External exposure monitoring, primarily in areas in whichlarge quantities of uranium concentrates and/or byproductmaterial are processed, packaged, and/or stored.

Internal exposure is documented by recording thederived air-concentration hours (DAC-hrs) of exposureto long-lived alpha emitters (uranium, thorium, radium),exposure to radon progeny in working level months, andbioassay results. External exposure is documented fromTLD results. CEDE resultant from internal exposuresand the TEDE as the sum of internal and externalexposure are typically calculated using methodsdescribed in, e.g., NRC Regulatory Guide 8.30,Health Physics Surveys in Uranium Recovery Facilities,2002.

Over the years, the NRC has issued a number ofhelpful regulatory guides specific to uranium recoveryfacilities, providing a solid basis and foundation for “goodhealth physics practice.” Typically, the agreement statesaccept these as appropriate to demonstrate compliance totheir own regulations commensurate with, e.g., NRC’s 10CFR 20 and 10 CFR 40. Examples include:

• 8.30 – Health Physics Surveys in Uranium RecoveryFacilities• 8.31 – ALARA Programs at Uranium Recovery Facilities• 8.22 – Bioassay at Uranium Mills• 3.56 – Emission Control Devices at Uranium Mills• 3.59 – Estimating Airborne Source Terms forUranium Mills

Conclusions—Opportunities for Health Physicists inthe Expanding Uranium Recovery Industry

Hopefully, this broad overview above suggests thatnumerous opportunities for health physicists and radio-logical scientists are emerging as a result of the rapidongoing expansion of the uranium recovery industry. Notonly are there opportunities to support the health physicsand related environmental-assessment and monitoringprograms of operating plants, but the preoperationallicensing process is arduous and can take several years.During this preoperational period, baseline radiologicalmonitoring programs must be designed and implementedand source material license applications and numerousother permits must be prepared. These regulatorysubmittals must describe, in some aspects in consider-able detail, the intended operational health physics andtraining programs and provide results of fate andtransport modeling efforts to estimate off-site publicexposure during operations, radiological design aspectsto ensure incorporation of ALARA principles into thefacility design and layout and for effluent control, anddescriptions of the planned operational environmentalmonitoring program. After the doldrums of the last 20-plus years, it is again an exciting time at the front end ofthe uranium fuel cycle.

Footnotes:1 In general terms, “source material” means either the element thoriumor the element uranium, provided that the uranium has not beenenriched in the isotope 235U. Source material also includes any combi-nation of thorium and uranium, in any physical or chemical form, thatcontains by weight one-twentieth of one percent (0.05 percent) ormore of uranium, thorium, or any combination thereof that is pro-cessed for its uranium and/or thorium content.2 A working level (WL) is the total potential alpha energy dissipatedin one liter of air from the decay of the short-lived daughters inequilibrium with 100 pCi/L of radon, equivalent to 1.3 x 105 MeV/liter of air; a working level month (WLM) is exposure to a concentra-tion in air of one WL for a working month of 170 hours. It is generallyassumed that 1 WLM = 12.5 mSv (1.25 rem) so that 4 WLM/y = 50mSv (5 rem)/y. Note however, that ICRP 65 (ICRP 1994) equates 1WLM to 5 mSv (500 mrem), which may be conservative.3 Natural enrichment means the mixture of the three naturally occur-ring isotopes of uranium as it occurs in nature, which is, on a massbasis, 99.3 percent 238U, 0.72 percent 235U, and 0.005 percent 234U.Due to differing half-lives, and therefore different specific activities,on an activity basis these ratios are 48.9 percent 238U, 2.2 percent 235U,and 48.9 percent 234U. By “definition,” the specific activity of natural


uranium is 0.67 µCi/g (10 CFR 20, Appendix B, Table 1, footnote 3).4 Over my career I have had the opportunity to have been the radia-tion safety officer at six different uranium recovery facilities thatproduced products of varying solubility depending on specifics ofprocess chemistry and the drying temperatures used (e.g., Task Groupon Lung Dynamics class D/W as well as Y—ICRP 1972). However,modern mill designs dry the final uranium product at much lower tem-peratures than in the past, producing more soluble products with lesspotential for pulmonary dose when inhaled (Brown 2008).

ReferencesBrown S, Smith R. A model for determining the radon loss (source)

term for a commercial in situ leach uranium facility. In: M. Gomez,ed. Radiation hazards in mining: Control, measurement, and medi-cal aspects. Soc Min Eng 794-800; 1981.

Brown S. Radiological aspects of uranium solution mining. Uranium1:37-52; 1982.

Brown S. The new generation of uranium in situ recovery facilities:Design improvements should reduce radiological impacts relativeto first generation uranium solution mining plants. Proceedings ofSymposium on HLW, TRU, LLW/ILW, Mixed, Hazardous Wastes& Environmental Management. American Society of MechanicalEngineers. Phoenix, Arizona; February 2008.

Camper L. NRC uranium recovery overview. Presentation at NuclearRegulatory Commission/National Mining Association Uranium Re-covery Workshop. Denver; April 2008.

Eidson F, Mewhinney J. In vitro solubility of yellowcake samples

from four uranium mills and the implications for bioassay inter-pretation. Health Phys 39:893-902; 1980.

International Commission on Radiological Protection. The metabo-lism of compounds of plutonium and other actinides. Oxford:Pergamon Press; ICRP Publication 19; 1972.

International Commission on Radiological Protection. Protectionagainst radon-222 at home and at work. Oxford: Pergamon Press;ICRP Publication 65; 1994.

National Mining Association. Generic environmental report in sup-port of the Nuclear Regulatory Commission’s generic environmen-tal impact statement for in situ uranium recovery facilities. No-vember 2007.

U.S. Nuclear Regulatory Commission. Regulatory Guide 4.14: Ra-diological effluent and environmental monitoring at uranium mills.Washington DC: Office of Nuclear Regulatory Research; 1980.

U.S. Nuclear Regulatory Commission. NUREG-0874: Internal do-simetry model for applications of bioassay at uranium mills; 1986.

U.S. Nuclear Regulatory Commission. Regulatory Guide 8.22: Bio-assay at uranium mills. Washington DC: Office of Nuclear Regula-tory Research; 1988.

U.S. Nuclear Regulatory Commission. Regulatory Guide 8.30: Healthphysics surveys in uranium recovery facilities. Washington DC:Office of Nuclear Regulatory Research; 2002.

Steve Brown, CHP, is president of SHBInc., a radiological consulting firm inCentennial, Colorado. Since forming hiscompany in early 2007, he has beenworking as a consultant in the uraniumrecovery industry supporting mining andengineering companies in the design andlicensing of new uranium recoveryprojects. He was recently appointed chairof the Uranium Committee of the Colorado MiningAssociation (see Health Physics News, July 2008). Herecently accepted an assignment to establish an officein the Denver area for SENES, the internationallyrespected Toronto-based mining and radiologicalconsulting firm.

After several years as a high school chemistry andphysics teacher, Steve joined the Uranium Division ofthe Westinghouse Electric Corporation in 1976 where hewas manager of ESH and RSO under six uraniumrecovery facility licenses. Steve left Westinghouse in1980 and started a Denver office for Radiation Manage-ment Corporation, a health physics consulting firm.Following the downturn in the domestic uranium industryof the early 1980s, Steve worked at DOE’s Rocky FlatsNuclear Weapons Plant as a senior nuclear safetyspecialist. He then joined Dames and Moore as seniorradiological engineer at the DOE’s West Valley Demon-

stration Project and subsequently started andmanaged a DOE and radiological servicesdivision for Dames and Moore. In 1992 hejoined the International Technology Corpo-ration (acquired by the Shaw Group in2002) as vice president of DOE programsand was appointed radiological operationsmanager in 2005. Steve has been a member of the HPS

since 1977, and twice president of the Central RockyMountain Chapter (1984 and again for 2008). He wasgeneral chair of the HPS’s midyear symposium onenvironmental radioactivity held in Colorado Springs in1985. He has served on the ABHP Part II exam panel andon many other HPS standing committees over the years.He received an associate degree in radiological health anda bachelor’s degree in physics from Temple Universityand master’s degree in physical science from WestChester University. Steve’s hobbies include traveling withwife Kathryn, art history (especially the Italian, Flemish,and Dutch renaissance), and hiking and climbing inColorado’s Rocky Mountains. Regarding the “rebirth” ofthe uranium recovery industry, Steve commented,“Uranium health physics was always my first love (after mywife Kathryn, sons Chad, Joshua, and Sean, and granddaugh-ter Sydney) and I am very excited to be back working in theindustry where I started over 30 years ago.”

Kathryn and Steve Brown withgranddaughter Sydney

Editor’s Note: More detailed information about ura-nium can be found at http://hps.org/publicinformation/ate/uranium.ppt.

1111111111 Health Physics News • November 2008

IntroductionUranium ore is mined from the ground in the chemical

form of U3O8. After the mining and separation of thenonuranium material from the uranium chemical com-pound, the material begins the next step in the nuclearfuel cycle. This step, called conversion, is summarizedby the Nuclear Regulatory Commission (NRC) (http://www.nrc.gov/materials/fuel-cycle-fac.html) as follows:

After the yellowcake is produced at the mill, thenext step is conversion into pure uranium hexafluo-ride (UF6) gas suitable for use in enrichment op-erations. During this conversion, impurities are re-moved and the uranium is combined with fluorineto create the UF6 gas. The UF6 is then pressurizedand cooled to a liquid. In its liquid state it is drainedinto 14-ton cylinders where it solidifies after cool-ing for approximately five days. The UF6 cyclinder,in the solid form, is then shipped to an enrichmentplant. UF6 is the only uranium compound that ex-ists as a gas at a suitable temperature. One conversion plant is operating in the UnitedStates: Honeywell International Inc. (Docket No.40-3392) in Metropolis, Illinois. Canada, France,United Kingdom, China, and Russia also have con-version plants. As with mining and milling, the primary risksassociated with conversion are chemical and ra-diological. Strong acids and alkalis are used in theconversion process, which involves converting theyellowcake (uranium oxide) powder to very solubleforms, leading to possible inhalation of uranium.In addition, conversion produces extremely cor-rosive chemicals that could cause fire and explo-sion hazards.

This is the third in a series of articles in Health Physics News that will explore the various sectors of nuclearpower that, while unique and relatively unfamiliar to our membership at large, share the basic science, principles,

and methods that are common throughout our profession. The first installment (Health Physics News, July 2008)presented a general overview of nuclear power generation—where it is today and where it’s headed tomorrow,environmental considerations, and some challenges and opportunities related to health physics. The second installment(Health Physics News, September 2008) presented the uranium recovery industry. This article focuses on the uraniumconversion and isotopic enrichment part of the nuclear fuel cycle.*



Uranium Conversion and Isotopic EnrichmentOrville Cypret, CHP, PE

The NRC explains the enrichment process as follows:

The fuel of a nuclear power plant is uranium,but only a certain type of uranium atom can beeasily split to produce energy. This type ofuranium atom—called uranium-235 (235U)—comprises less than 1 percent by weight of theuranium as it is mined or milled. To make fuelfor reactors, the natural uranium is enriched toincrease the concentration of 235U to 3 percent to5 percent.

Throughout the global nuclear industry, uraniumis enriched by one of two methods: gaseous dif-fusion or gas centrifuge. A third method—laserenrichment—has been proposed for use in theUnited States.

History of Isotope Separation TechnologyVarious isotope separation processes were investigated

in the late 1930s and early 1940s by Harold Urey andothers. Immediately prior to World War II, no consensusexisted within the scientific community that the fissionprocess could be used to make a weapon. However, thisperspective made a radical and rapid about-face in theearly 1940s within some of the Allied governments andtheir associated scientific communities. During theManhattan Project in World War II, gaseous diffusionbecame the method of choice for uranium enrichment.The process essentially involves presenting a porousmaterial to gaseous UF6. The 235UF6 will diffuse through

Health Physics News • November 2008 1212121212

the material at a very slightly higher rate than the 238UF6.This results in the UF6 on one side of the porous materialhaving a slightly higher concentration of 235U while theUF6 on the other side of the porous material has a slightlydepleted concentration of 235U.

The first gaseous diffusion plant in the United States,K-25, was built in Oak Ridge, Tennessee. Additional plantswere built within a few years at Paducah, Kentucky, andPiketon, Ohio. All used the gaseous diffusion process.

The following graphic is a depiction of a gaseousdiffusion stage. Each stage is several feet in length andabout half as big in diameter as its length. Buildingshousing the cascade are approximately square and about1,000 feet on each side. Many stages are connectedtogether in series to form a cascade. In the cascade, theenriched stream is fed into the next stage upstream ashigh-pressure feed material. Thus, each stage providesan incremental amount of enrichment and the cascade,which may consist of several thousand stages, collec-tively provides substantial isotopic enrichment.

The effort required to separate the 235U atoms from the238U atoms is measured in “separative work units”(SWU). Customers contract with enrichers based on theamount of natural uranium they can supply and thenumber of SWUs needed to reach their desired productquality and enrichment level. In fact, regardless of thetechnology used to accomplish the enrichment, theenriched product is purchased based on the number ofSWUs it has undergone.

The changing market demand for enriched uraniumover the past 20 years or so has impacted the viability ofthe domestic enrichment enterprise and two of the plantshave ceased uranium enrichment operations. K-25ceased enrichment operations in the mid-1980s and theplant in Piketon, Ohio, ceased enrichment operations in2001. Only the plant at Paducah, Kentucky, still operates.

Future Technology DevelopmentsElectricity requirements of the gaseous diffusion

process are very high. This is the primary reason theprocess is being phased out and replaced by alternativetechnologies with lower energy consumption. Thesecond-generation technology currently in use is gascentrifuge. A third-generation technology using lasers to

Gaseous Diffusion Stage Courtesy of USEC, Inc.

achieve enrichment has been in development for severaldecades.

Plants using updated U.S. and European gas centrifugetechnologies are under construction in the United States.Enrichment plants using European and Russian centri-fuge technologies have operated in Europe, Russia, andChina for some time.

Isotopic enrichment by gas centrifuge technologyinvolves injecting gaseous UF6 into a rotor that isspinning rapidly inside a casing. The inner void annulusspace between the rotor and the casing is held at avacuum. The rotor spins and places the contained UF6gas under a centrifugal force that results in the heavier238UF6 molecules being preferentially moved closer to theouter wall of the rotor than the lighter 235UF6 molecules.

The graphic on the next page schematically representsa centrifuge. The UF6 gas is injected in the line on the leftside of the device; the stream enriched in 235UF6 iswithdrawn at the top, and the depleted stream is with-drawn from the line on the right side. The casing androtor (as described above) are shown, as is the motorthat spins the rotor.

A countercurrent axial flow may also be induced in thegas inside the rotor which can enhance the separation ofthe isotopes and result in a concentration of the enrichedgas being found at one end of the rotor and a concentra-tion of depleted gas being found at the other end of therotor. Centrifuges have a large length-to-diameter ratioand spin at very high speeds because the isotopicseparation efficiency varies directly with the length ofthe rotor and its rotational speed.

In terms of enriched product produced per unit ofenergy consumed, gas centrifuge enrichment technologyis more efficient than gaseous diffusion but less efficientthan laser enrichment. Two centrifuge designs arecurrently being fielded in the United States but detailedtechnical differences between the designs have not beenpublicly disclosed.

To date, laser enrichment has not been used on anindustrial scale to commercially enrich uranium. Laserenrichment is thought to be the most efficient of theenrichment technologies in that it provides the greatestmass of enriched product for the least amount of energyconsumed. The technique being considered for com-mercial deployment is known as the SILEX technology.

The SILEX process is considered classified technol-ogy by the United States and Australian governments, soalmost no technical details of it are publicly available.However, the process is thought to involve passinggaseous UF6 through a laser beam. The laser wavelengthis tuned to preferentially excite the 235U atoms in the UF6molecules. The excited atoms are electrically chargedand, when placed under the influence of an electromag-

1313131313 Health Physics News • November 2008

2

1

3

4

Gas CentrifugeCourtesy USEC, Inc.

netic field, can be deposited on a collecting surface orsubstrate.

The uranium deposited on the collecting surface willbe enriched in very pure 235U. Process losses inherent inthis method include less than 100 percent of the gaseousUF6 being excited by the laser and failure to deposit allthe excited atoms on the collecting surface. However,even with these process losses, the technology isreported to be the most efficient isotopic separationmethodology available at this time.

Health Physics ConsiderationsOccupational radiation dose will come from charged

particles, i.e., alpha and beta particles, and gammaemissions interacting in both the external and internalexposure pathways. Exposure to radiation from sponta-neous fission events is also possible, but the incidence ofthese events is quite low.

Specific activity of uranium, natural or enriched, isrelatively low due to the long half-lives of the constituentisotopes. The specific activity of a mass of uranium,whether natural or enriched, is on the order of 3.7 x 104

Bq (10-6 Ci) g-1. It’s important to note that the grand-daughter of 238U decay, 234mPa, emits a relatively high-energy 2.29 MeV beta particle. The significance of the234mPa decay is that it can result in a surprisingly intensebremsstrahlung photon radiation field in favorablegeometry.

Generally before an internal exposure can occur at anenrichment facility, UF6 must be released from theenclosed process system to the atmosphere. When it isreleased to open air, UF6 quickly hydrolyzes with watervapor in the air to uranyl fluoride (UO2F2) according tothe following equation:

2H2O + UF6 —> UO2F2 + 4HFIn a facility that uses UF6, intakes following a release

will be of the chemical UO2F2, which metabolizes veryquickly, is very soluble in body fluids, and has a veryshort biological half-life. Because the emissions aretypically low-energy particles or photons, in vitrobioassay by urinalysis is a typical method for determiningthe intake mass and estimating the internal dose. Itshould be noted that the 10 CFR 20 limit on solubleuranium intake is based on mass (10 mg U per week),not dose, due to the fact that the limiting hazard of anintake is the chemical effect of uranium’s nephrotoxicityas a heavy metal rather than its consequential radiogenicpathology.

The primary external dose at gaseous diffusion plantscomes from charged particles and photons emitted by Uand its daughters. Internal dose results from solubledecay progeny that emit charged particles, 234Th and230Th being major contributors. Both 234Th and 230Th are

1. Gaseous UF6 is fed into a rotor that spins inside acasing.2. The useful, lighter 235U isotopes remain at the centerof the rotor while centrifugal force pushes the heavier238U isotopes toward the rotor walls.3. The 235U gas (enriched stream) is extracted at the top.4. The 238U gas (depleted stream) is extracted at theright.

The process is repeated in several connectedcentrifuge machines, known as “cascades,” until thedesired level of 235U is achieved.

Health Physics News • November 2008 1414141414

in the 238U decay chain. Contamination control is thegreatest health physics challenge at these plants. Areasrequiring radiological control are posted and con-trolled by the Health Physics Group in accordancewith the requirements of 10 CFR 20. Engineeredfeatures or respirators are used to minimize internalcontamination and workers monitor themselves forradiological contamination when they exit contaminationareas.

In a centrifuge plant operating in the United States, thesource term for occupational radiation dose is uraniumand its daughters. This being the case, the primarysource of external occupational dose would be expectedto be charged particles and photons emitted fromradionuclides in the uranium decay chain. As withgaseous diffusion, the principal source of internal dose isthe soluble radionuclides in the uranium decay chain thatemit charged particles.

Laser enrichment may present some unique occupa-tional radiological control situations because the feedmaterial can be either metal or UF6 and the product isprimarily 235U deposited on a substrate. Based on what isknown about this process, the occupational doses will

probably be approximately the same as the doses fromcentrifuge or gaseous diffusion enrichment plants.

ConclusionUranium is currently enriched using the gaseous

diffusion and gas centrifuge methods. Beginning in thenext decade, uranium may be commercially enriched byusing laser enrichment technologies. Gaseous diffusiontechnology is likely to be used for some time to comebut will most likely be gradually phased out as the moreenergy-efficient technologies become available. Theoccupational radiation dose considerations are similar foreach of these methodologies. Generally, a person’sexternal dose will probably not exceed 5 mSv y-1 (500mrem y-1) and may be much lower. Internal dose willresult primarily from alpha-particle emitters in theuranium decay chain. Internal dose from routine opera-tions will probably not exceed a few µGy (mrem) in anygiven year.

*Editor’s Note: Due to space limitations and securityrestrictions, many details of these processes are notincluded in this article.

Orville with his grandchildren Gavin andHannah

Orville Cypret, CHP, PE, is em-ployed by the U.S. Enrichment Corp-oration as the principal health physi-cist at the Paducah Gaseous DiffusionPlant in Paducah, Kentucky. He re-ceived a BS in metallurgical engineer-ing (nuclear option) from the Univer-sity of Missouri-Rolla (now MissouriScience and Technology) in 1974 andan MS in radiological health from theUniversity of Arkansas in 1990. He is a registeredprofessional engineer and a certified health physicist.

Orville worked for Arkansas Power and Light(AP&L) from 1974 until 1992. He was one of twonuclear engineers overseeing the initial approach tocriticality of Arkansas Nuclear One-Unit 1 in 1974 andwho determined the reactor had achieved initial critical-ity. He served in several positions while at AP&L innuclear engineering and health physics. During his timewith AP&L, the construction of Arkansas Nuclear-Unit1 and Unit 2 was completed and both plants wereplaced into commercial service.

He joined Martin Marietta Energy Services (eventu-ally replaced by the United States Enrichment Corpora-tion) at the Paducah Gaseous Diffusion Plant in 1992as the dosimetry manager and was named the radiation

protection manager in 1993. In thisposition, he was responsible for theeffort to modify the RadiologicalProtection Program from compliancewith Department of Energy rules andexpectations to a 10 CFR 20-compli-ant program in preparation foroperation of the plant under theregulatory jurisdiction of the NuclearRegulatory Commission. As the

principal health physicist at the plant, he is responsiblefor providing technical assistance to the plant manage-ment in health physics and nuclear engineering and otherproject-related activities.

Orville and Dianne, his wife of 35 years, have twoadult children, Aaron and Amy, and two grandchildren,Hannah and Gavin. Trips with the grandkids are the wayweekends are frequently spent.

Orville’s main hobby is amateur radio. He is also amember of the Army Military Affiliate Radio System, avolunteer organization that provides emergency radiocommunications services to various groups, including theU.S. Department of Homeland Security, the American RedCross, and the Salvation Army, in times of disaster.Hurricanes Gustav, Hanna, and Ike have kept him verybusy this year.

Health Physics News • January 2009 1010101010

Fuel FabricationIn the simplest terms, fuel fabrication is the process of

transforming refined enriched uranium into finished fuelassemblies suitable for direct placement into the reactorcore.

The details that go into that transformation are numer-ous and diverse. Every component of the fuel assem-bly—the fuel cladding, the end plugs, the tie plates, evenseemingly mundane springs—must be designed andmanufactured to meet the demanding environment of anuclear reactor core.

The uranium itself must be chemically processed,pelletized, sintered into a ceramic, and ground to toler-ances of 1/1000ths of an inch.

Then everything must be assembled—the pellets intothe cladding, the loaded rods into assemblies—andprepared for shipment to the customer.

A fuel fabrication facility is actually the combination ofa chemical processing plant, a components manufactur-



This is the fourth in a series of articles in Health Physics News that will explore the various sectors of nuclearpower that, while unique and relatively unfamiliar to our membership at large, share the basic science, principles,

and methods that are common throughout our profession. The first installment (Health Physics News, July 2008)presented a general overview of nuclear power generation—where it is today and where it’s headed tomorrow,environmental considerations, and some challenges and opportunities related to health physics. The second installment(September 2008) covered the uranium recovery industry, and the third (November 2008) summarized the uraniumconversion and isotopic enrichment processes. This month’s article focuses on the fuel fabrication process.

ing plant, a ceramics production facility, and an assemblyoperation (see Figure 1).

The fuel fabrication process begins with the reconver-sion of the uranium hexafluoride (UF6) received from theenrichment facility. Reconversion, also referred to asdefluorination, is the process of transforming the UF6back to a chemically stable oxide state, essentiallyreversing the fluorination process that was necessary tofacilitate enrichment. The UF6 is received as a solid in30-inch-diameter cylinders suitable for connectingdirectly to the chemical process. Each cylinder containsabout one metric ton of uranium. The most commonindustry method of reconverting uranium hexafluoride touranium dioxide (UO2) is the ammonium diuranate(ADU) process, which is a fairly involved multistagechemical process. It requires large centrifuges andreaction tanks, and it produces a high volume of liquidwaste that must be treated to remove the fluorides andnitrates, as well as small amounts of uranium.

Fuel FabricationAllen M. Mabry, CHP

Figure 1. Typical light water reactor fuel fabrication facility

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Some fabricators have adopted what isreferred to as a dry process, which ismuch less resource intensive and doesn’tgenerate a liquid waste stream. In fact,the byproduct of the dry process is cleanhydrofluoric acid suitable for industrialsale. Both processes rely on a hydrolysisreaction, which is accomplished byheating the UF6 cylinder to achieve agaseous state and introducing the UF6gas to a vessel where it is mixed withH2O. The hydrolysis reaction is rapid andexothermic:

UF6 + 2H2O —> UO2F2 + 4HFThe dry process uses super-heated steam to hydrolyze

the UF6, while the ADU process injects the UF6 gas intoroom-temperature water. To complete the dry process,the UO2F2 is heated in a reducing atmosphere that stripsaway the remaining fluoride, resulting in the desired UO2powder. The ADU process requires the addition ofammonium hydrox-ide to precipitate theuranium fromsolution. Theprecipitate must beseparated by centri-fuge and then heatedin a reducingatmosphere thatremoves the remain-ing fluoride.

Other chemicalprocesses of fuelfabricators are thoseassociated withscrap recovery andwaste treatment.These typicallyinvolve nitric aciddissolvers, solventextraction columns,drying ovens,dewatering centri-fuges, and variousfiltration systems.Clearly, chemistryplays a big part inthe fabricators’business.

After the finishedUO2 powder leavesthe chemical pro-cess, it is physically

manipulated to achieve the desirabledensity and particle size for pressing intofuel pellets. Pelletizing operations usehigh-pressure precision punches and dyecavities to form dense slugs of UO2.These slugs are then sintered in high-temperature furnaces to form hard,dense ceramic pellets. Typical UO2pellets are small cylinders about one cmin length and one cm in diameter (seeFigure 2). Individual pellets are loadedinto tubular cladding end to end to form

a column of fuel. The cladding ends are sealed andwelded closed and then assembled with spacers and tieplates to form a finished fuel bundle. Figure 3 illustratesthe many components of finished fuel bundles in aboiling water reactor (BWR). A pressurized water reactor(PWR) fuel bundle has basically the same componentsand complexity.

The fuel fabricators also do more than just manufac-ture fuel. They provide the fuel design, incorporating the

latest technologiesfor extending thereliability of the fuel,thereby providinglonger cyclesbetween refuelingand achieving morepower per operatingcycle. The fabrica-tors also design andmanufacture controlrods, control roddrives, fuel channels,and reactor compo-nents. They provideservices such as fuelinspection and coredesign. Some evenhave facilities forhandling contami-nated tooling andequipment used atnuclear power plantsby their company’snuclear services andfuel-inspectionoperations.

History Large-scalecommercial produc-tion of nuclear fuel

Figure 2. Uranium pellets are shownhere next to a coin. One pellet isequivalent to the energy provided by aboxcar of coal or three barrels of oil.

BWR/6 FUELBWR/6 FUELBWR/6 FUELBWR/6 FUELBWR/6 FUEL

ASSEMBLIESASSEMBLIESASSEMBLIESASSEMBLIESASSEMBLIES

& CONTROL& CONTROL& CONTROL& CONTROL& CONTROL

ROD MODULEROD MODULEROD MODULEROD MODULEROD MODULE

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began in the late 1960s and early 1970s along with theconstruction of the first commercial nuclear powerplants. After working on large nuclear projects for theDepartment of Defense and the Atomic Energy Commis-sion during and after World War II, large household-name companies like Westinghouse, General Electric,Exxon, and Babcock and Wilcox were well positioned tostep into the commercialization of nuclear energythrough the design and construction of nuclear powerplants, as well as the fuel that would power them. Thedomestic commercial (nondefense-related) fuel fabrica-tion facilities in operation today are the same facilitiesstarted by these companies nearly four decades ago.

Much has changed though. After a long period of rapiddomestic growth, the fuel fabrication business wasslowed after the last U.S. plants came on line in the1980s. During the same period, the fuel business hadbecome more and more global, meaning the fabricatorshad a larger customer base, but the customers had alarger market to shop. This resulted in stiff competitionbetween fabricators and eventual consolidation ofbusinesses. Today the market has a very global feel, with all of thedomestic players now either owned by or affiliated withoverseas companies like Areva, Toshiba, and Hitachi.The products offered have also changed over thedecades as fuel bundle designs have evolved to achievehigher burnup and longer cycles through the use ofhigher enrichments, the addition of burnable poisons, andthe incorporation of advanced computer modeling of thereactor core thermodynamics and neutronics.

Health Physics Low-enriched uranium (LEU) is a mixture of uraniumisotopes and their short-lived progeny. It is a fairly low-specific-activity material when compared to the materialencountered by reactor or medical health physicists. LEUis also a low-dose-rate material. There are photon andelectron emissions to consider, but the predominantphoton emission energies are less than 200 keV, and theuranium itself is a dense high Z material that providesconsiderable shielding. In fact, the self-shielding effectresults in a dose rate to quantity of material relationshipthat peaks quickly at less than 0.05 mSv h-1 for a fewkilograms of uranium (whole-body deep dose at 30 cm)and plateaus as the quantity increases. The shallow doserate behaves similarly, peaking at about 2 mGy h-1

(shallow dose at contact).The level of enrichment influences the specific activity

and consequently the external dose levels. LEU rangesfrom 1 percent to 5 percent enriched in 235U, with arange of specific activity of approximately 40 to 120kBq g-1. As the nuclear industry has gradually increased

the average enrichment level utilized in the reactor cores,the consequence has been to slightly increase externaldose at the fuel fabrication facilities. Another driver ofthe external dose rate of LEU is the ingrowth of the LEUprogeny following the vaporization stage. The vaporizationof UF6 to feed the reconversion process acts as a distilla-tion that purifies the UF6 as it enters the process, leavingthe progeny behind in the cylinder. As time elapses duringthe processing of the uranium, the short-lived progenybegin to grow back in, reaching full equilibrium in about100 days. Current business practices that emphasize highturnover rates of inventory result in lower external dose tothe workforce as the progeny are not given time to reachequilibrium before the product is shipped. In general theexternal dose at a fuel fabrication facility is low, with themaximum expected deep dose less than 10 mSv y-1 andaverage deep dose less than 1 mSv y-1.

Conversely, the internal dose due to inhalation of LEUis an important consideration for the fuel fabricationindustry. Even though the material is of low specificactivity, a very small amount released to the air can create asignificant airborne concentration of alpha-emittinguranium isotopes. The enrichment process that increasesthe amount of 235U also increases the 234U content, which isthe primary contributor to LEU alpha activity. The industryincrease in average enrichment level mentioned above hasincreased the average alpha activity of material processedby the fuel fabricators by a factor of two to three duringthe operating history of the industry, which withoutchanges to the processes would have proportionallyincreased worker dose.

With an inhalation dose coefficient of 6.8 x 10-6 Sv Bq-1,the insoluble category of uranium (UO2, U3O8) has one ofthe lowest annual limit on intake values in 10 CFR 20Appendix B. Keep in mind the fuel fabricators areprocessing many kilograms of uranium daily, includingmanual operations requiring workers to handle andmanipulate the uranium through the process. As a result,much of the radiation protection activity at a fuelfabricator relies heavily on containment, proper ventila-tion, contamination control, and respiratory protection.

The health physics monitoring programs are focusedon air sampling, contamination monitoring, in-vivobioassay, and in-vitro bioassay. While internal dose is themain contributor to the total dose of the workforce,another consideration of handling large quantities of LEUis the potential chemical toxicity of the soluble com-pounds of uranium, e.g., UF6 and UO2F2. In fact, theonly nonradiological exposure limit in 10 CFR 20 is theweekly exposure limit of 10 mg soluble uranium.

Fortunately, the radiation protection measures men-tioned above are equally effective at limiting exposure tothese compounds, and the health physics monitoring of


Allen Mabry, CHP, is theradiological safety programmanager at the Global NuclearFuel – Americas, LLC, fuelfabrication facility inWilmington, North Carolina,where he has been since joiningGeneral Electric (GE) in 1992.

He is also the radiation safetyofficer for the site byproductmaterial licenses, which includefacilities for handling highlyradioactive tools and componentsused at nuclear power plants.

Before coming to GE, Mabrywas a health physicist with theNorth Carolina agreement stateprogram.

He began his career in healthphysics at the University ofNorth Carolina (UNC) radiationsafety office.

Mabry serves on the NorthCarolina Radiation ProtectionCommission and chairs thecommission’s committee on low-level radioactive waste.

He is active in the HealthPhysics Society (HPS), cur-rently chairing the InternalDosimetry for Uranium standard

working group, and is a pastpresident of the HPS NorthCarolina Chapter.

He also leads the very informalbut long-standing Uranium UsersGroup, which is comprised ofprofessional health physicistsfrom the uranium fuel fabricationindustry.

He received his BA (chemistry)and MS (radiological hygiene)degrees from UNC.

Allen and his wife Susan enjoyliving at the coast, spending mostof their spare time boating andfishing. They are also hugeTarheel fans, and during the fallof the year when the UNCfootball team is playing at home,they can usually be found inKenan Stadium cheering for thehome team.

Allen and Susan Mabry

radiological conditions conserva-tively bounds the chemical toxicityconcerns.

As with most health physicsprograms, there is overlap andshared responsibility with the otherhealth and safety and environmental-protection disciplines. LEU process-ing intermingles the radiological workenvironment with hazardous chemi-cals and heavy machinery. The efflu-ent monitoring programs and controlshave radiological considerations as aprimary component. The programsand controls to prevent accidentalcriticality of the fissile material havesignificant radiological implications.To a lesser degree, the emergency

preparedness, fire safety, security,and special nuclear material safe-guards programs all have radiologicalaspects or considerations as well.

The FutureThe future challenge for fuel

fabrication is not just an increase indemand for fuel to supply newreactors as a result of a nuclearexpansion. Certainly the increasednumber of finished fuel assembliesneeded to support the proposed newplants domestically and internation-ally will necessitate expansion ofmanufacturing capacity, but thelarger challenge will be adapting tothe demand for new fuel types that

incorporate higher enrichments,reprocessed uranium, and mixedoxide fuel.

From a health physics perspec-tive, adapting to the new fuel typesmeans manufacturing processes willneed to be engineered to accommo-date higher dose rates and higherspecific-activity materials, andfuture monitoring programs willneed to adapt to the increasedexternal exposure hazard, the greaterinternal exposure potential associ-ated with higher alpha-activity fuels,and the monitoring challengespresented by transuranics and mixedfission products not currently foundin virgin uranium.

Uranium Terminology Simplified

Virgin—natural, i.e., no isotopic separation or irradiation has taken place.Refined—chemically and physically processed to separate it from the uranium ore.Enriched—processed to increase the weight fraction of the isotope 235U.Reprocessed—recovered from irradiated fuel, has fission product and transuranium element contaminants.Mixed Oxide Fuel (MOX)—uranium fuel with fissile plutonium added to it.Low-Enriched Uranium (LEU)—has a lower than or equal to 20 percent concentration of 235U.High-Enriched Uranium (HEU)—has a higher than 20 percent concentration of 235U.

President’s Message........................................... 2

Inside the Beltway........................................... 9

Chapters........................................... 9

Correspondence.......................................... 10

Committee Activities.......................................... 11

Notes.......................................... 12

Thinking Outside the Box.......................................... 13

Announcements.......................................... 14

Book Review.......................................... 15

HPS Midyear Meeting Photos.......................................... 16

HPS Standards Corner.......................................... 18

REAC/TS Case File.......................................... 19

CHP Corner.......................................... 21

Display Ads......................................... 23

Short Courses......................................... 27

Odds and Ends......................................... 32

Volume XXXVolume XXXVolume XXXVolume XXXVolume XXXVII VII VII VII VII Numbe Numbe Numbe Numbe Number 3 r 3 r 3 r 3 r 3 For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety For Specialists in Radiation Safety March 2009 March 2009 March 2009 March 2009 March 2009

The Official Newsletter of the Health Physics Society

In This IssueIn This IssueIn This IssueIn This IssueIn This Issue

(continued on page 3)



TThis is the fifth in a series of articles in Health Physics News that provide anoverview of nuclear power so that the effect of a resurgence of this energysource on the profession of health physics can be anticipated. The first fourinstallments (Health Physics News July, September, and November 2008 andJanuary 2009) presented an overview of nuclear power generation, theuranium recovery industry, the uranium conversion and isotopic enrichmentprocesses, and the fuel fabrication process. This month’s article is the first ina two-part story on the history, status, and outlook for nuclear power in theUnited States. The upcoming second part will focus on how health physicsis fully integrated across all aspects of nuclear power plant design, construc-tion, startup, operation, emergency preparedness, and decommissioning.

“The more important responsibilityof this atomic energy agency wouldbe to devise methods whereby thisfissionable material would beallocated to serve the peacefulpursuits of mankind. Experts wouldbe mobilized to apply atomic energyto the needs of agriculture, medicine

History, Status, and Outlook for Nuclear Power in the U.S.

and other peaceful activities. Aspecial purpose would be to provideabundant electrical energy in thepower-starved areas of the world.”— Address by President Dwight D.Eisenhower to the 470th Plenary Meeting ofthe United Nations General Assembly onTuesday, 8 December 1953

33333 Health Physics News • March 2009


(continued from page 1)

In his “Atoms for Peace” address to the UnitedNations General Assembly more than 50 years ago,President Eisenhower set the stage for the creation of theInternational Atomic Energy Agency andlaunched a global effort to “help solvethe fearful atomic dilemma—to devote itsentire heart and mind to finding the wayby which the miraculous inventivenessof man shall not be dedicated to hisdeath, but consecrated to his life.”

The following year, the U.S. Congresspassed the 1954 Atomic Energy Act, which opened thedoor for the first time for commercial industry toparticipate in “the development and utilization of atomicenergy for peaceful purposes.” The act expanded therole of the Atomic Energy Commission (AEC) beyond itsongoing weapons program to also promote beneficialuses of nuclear materials and create regulations toprotect public health and safety against radiation hazards.Thus, the AEC was mandated to carry out a dual missionof promoting the use of nuclear technology while alsoassuring its safety.

Creating a Regulatory FrameworkFollowing passage of the Atomic Energy Act, the AEC

began promulgating regulations and writing internalprocedures necessary to license commercial nuclearpower plants. The AEC developed a two-step licensingprocess. In the first step, a company would provide theAEC a detailed safety analysis for the design and opera-tion of a proposed power reactor. After review andacceptance of the company’s safety analysis, the AECwould issue a construction permit to allow the companyto build the plant. When construction was completed andthe AEC had assured that all of the safety requirementshad been met, then the AEC would issue a license for thecompany to load fuel and operate the reactor.

At the outset, the AEC understood that some technicaldata regarding the reactor design or operating procedureswould not be fully developed and available at the time ofsubmittal of applications for construction permits. Thetwo-step licensing process gave AEC the flexibility toissue conditional permits for construction if the applica-tion included sufficient information for the Commissionto conclude with “reasonable assurance” that the plantcould be constructed and operated without undue risk topublic health and safety.

In parallel to creating a licensing framework, the AECpromulgated regulations for radiation safety in 1955 thatwent into effect in 1957. In doing so, the AEC drew

upon the recommendations of two expert organizations,the International Commission on Radiological Protec-tion (ICRP) and the National Committee on RadiationProtection (NCRP—later renamed National Council onRadiation Protection and Measurements), to set“maximum permissible dose” limits for nuclear

workers and the public.Prior to the AtomicEnergy Act, the AEC hadalready employed theNCRP occupational doselimits at its own facilities,and the agency carriedover the same limits into

its regulations for workers at commercial facilities. Inits new regulations, the AEC also adopted the ICRPrecommendation that public dose limits be set at one-tenth of the occupational dose limits.

In carrying out its mandate for promoting nuclearenergy, the AEC conceived a program in which thegovernment and industry would jointly pursue thedevelopment and deployment of commercial nuclearpower plants. The purpose of the program was toengage the industry in demonstrating that nuclear powerwas technically and economically feasible within acompetitive energy market. The AEC, through itsnational laboratory program, would sponsor necessaryresearch and development efforts, while the industrywould finance the construction and operation of theplants. The AEC would also provide the nuclear fuel on asubsidized basis for use by the commercial power plants,with ownership of the fissionable materials ultimatelybeing retained by the government.

First Power ReactorsThe initial response by industry to the AEC proposal

for joint projects was mixed. Three companies steppedforward to participate in the joint demonstration pro-gram, while two other companies announced plans toconstruct and operate nuclear power plants outside ofthe joint demonstration program. Although the AEC waspositive about getting these responses, the congressionaljoint committee providing oversight of the atomic energyprogram was not. The Democrats on the committee, ledby Senator Albert Gore and Representative Chet Holifield,pushed legislation to direct the AEC to construct sixdifferent pilot reactor types to advance commercialnuclear energy “at the maximum possible rate,” but thelegislation narrowly failed to pass. Subsequently, othercompanies weighed in with plans to proceed on theirown, and since the time of the demonstration projectreactors, nuclear power plants have been funded,owned, and operated by the utility companies.

Following passage of the Atomic EnergyAct, the AEC began promulgatingregulations and writing internal proceduresnecessary to license commercial nuclearpower plants.

Health Physics News • March 2009 44444

A number of differentreactor technologieswere represented amongthe plants licensed andoperated in the firstdecade of commercialnuclear power in theUnited States. Thisincludes what becamethe mainstays of the U.S.nuclear power plantfleet, the boiling-waterreactors (BWRs) and thepressurized-waterreactors (PWRs) (see Ain the Reactor Designs synopsis above) as well as othertypes of reactors, including a pressure-tube heavy-waterreactor, a high-temperature gas-cooled reactor, anorganically cooled and moderated reactor, a graphite-moderated reactor, and a liquid-metal fast breederreactor. Following the diversity of reactors that wereoperated briefly in the early days, only one other powerreactor type (i.e., besides BWRs and PWRs) has beenoperated commercially in the United States—Fort St.Vrain, a high-temperature helium-cooled reactor loadedwith uranium-thorium fuel blocks, which operated inColorado from 1976 to 1989.

Rapid BuildupBy the early 1960s, 14 nuclear power plants were

operating or under construction. But the reactors weregenerally not economically competitive with other energysources. However, in the mid- to late 1960s, severalfactors emerged that had the effect of greatly improvingthe economics and desirability of building new nuclearpower plants to meet the rapidly increasing demand forelectrical energy in the United States. First, one of theprimary vendor companies for nuclear power plants,General Electric (GE), introduced the concept of a“turnkey” plant that involved delivery of one each fully-constructed, ready to operate, nuclear power plant for afixed cost. The idea was that the buyer utility would onlyneed to turn the key to start up and operate the reactor.The first reactor ordered and constructed under thisconcept was the 515 megawatt Oyster Creek BWR thatbegan operation in New Jersey in 1969 (and continues tooperate today). The turnkey approach became a morecommon practice that greatly accelerated reactor orders. A second factor involved changes in power distributioncontracts within the United States, in which reservepower from one plant or utility could be more readilysold and distributed elsewhere within the country. Thispooled power concept shifted the economics in favor of

large-base-load generat-ing units that couldproduce and sell poweryear-round. This helpedto facilitate constructionand startup of a newgeneration of muchlarger nuclear powerplants than had previ-ously been placed intooperation. In fact, thedesign capacity of theplants expanded rapidlyfrom a 200-500 mega-watt range to more than

1,000 megawatts. This helped to offset the substantialcapital costs involved in constructing a nuclear powerplant versus the lesser costs of constructing nonnucleargenerating stations. However, the design and operationalcomplexities involved in doubling or tripling the capacityof a power reactor were proving to be exponential,rather than linear.

A third factor that influenced a shift to increased useof nuclear power was the emerging concern over airpollution. Coal plants were viewed as a major contributorto air pollution, which led to increased costs in the formof required pollution control systems. This helped bringnuclear power closer to a head-to-head economicposition with coal-fired power plants. As a result of these and other fundamental economicand social changes, 68 nuclear power plants were orderedin the three-year period of 1966-1968. In the ensuingdecade, estimates of up to 400 nuclear power plants in theUnited States were becoming commonplace and the catchphrase of the day was that nuclear-generated electricitywould become “too cheap to meter.”

Nuclear Regulatory CommissionDuring the late 1960s and early 1970s, there were a

myriad of construction and operating license applicationssubmitted, extensive licensing reviews by an ever-growing regulatory staff, and numerous adjudicatoryhearings under the Atomic Safety and Licensing Boards,all of which produced new and evolving technical issuesand a growing public interest and concern about reactorsafety. Underlying this was an increasing uneasinessamong legislators and the public about the dual mandateof the AEC to both promote and regulate nuclear energy.

With a backdrop of the oil embargo and energy crisisthat unfolded in the early 1970s, President Richard Nixonasked Congress to consider the creation of a separateagency to oversee the licensing of nuclear power plantsthat would not be conflicted with a promotional mission.

Reactor Designs

A. Existing Operating Plants• BWR – Boiling Water Reactor—GE• PWR – Pressurized Water Reactor—Babcock & Wilcox,Westinghouse, and Combustion Engineering

B. New Designs – (New Acronyms; Some New Players)• ABWR – Advanced BWR—GE• AP-1000 – Advanced PWR—Westinghouse• ESBWR – Economic Simplified BWR—GE-Hitachi• EPR – European Pressurized Reactor—AREVA• US-APWR – US Advanced PWR—Mitsubishi


This request was made with the idea that such an indepen-dent agency could better and more directly address theemerging public confidence issues and thereby actuallyfacilitate licensing of the plants. The Congress respondedby passing the Energy Reorganization Act of 1974, whichhad the effect of splitting the AEC into the Energy Re-search and Development Administration (which latermorphed into the Department of Energy) and the NuclearRegulatory Commission (NRC).

The NRC took over the licensing and regulatoryoversight responsibilities previously carried out by theAEC, not only for nuclear power plants, but also for therapidly increasing number of radioactive materialslicensees. In the first few years following creation of thenew agency, considerable effort was expended onadministrative and organizational matters, as well asredefining the scope and processes for activities that hadpreviously been part of the multifaceted mission of theAEC. Perhaps the most unique and interesting aspect ofthis period was the evolution of an institutional cultureand values that were intensely focused on nuclear safety,material safeguards, and the protection of public healthand the environment. This transformation became fullyrealized with the occurrence of a major reactor accidentat Three Mile Island.

Three Mile IslandIn the early morning of 28 March 1979, Unit 2 of the

Three Mile Island (TMI) nuclear power plant in Pennsyl-vania automatically shut down when a main feedwaterpump (which supplies water to the reactor) stoppedrunning. As the pressure and temperature inside thereactor vessel increased, a pressure relief valve openedand water and steam were released out of the reactorinto a receiving tank (as designed).

However, when the pressure and temperature camedown to a point where the relief valve should haveautomatically closed, the valve stuck open, allowingwater and steam to continue to flow out of the reactor.This equipment malfunction was not indicated correctlyby the instrumentation in the plant control room. In fact,the operators in the control room received an indicationthat the relief valve was closed and that water was beingpumped into the reactor.

What followed was a series of events that, whencompounded by the misunderstanding of plant condi-tions by the reactor operators, ultimately resulted in aloss of cooling water to the reactor core and a partialmelting of the fuel rod cladding and uranium fuel. All ofthe fuel was damaged. 700,000 gallons of reactorcooling water ended up overflowing into the basementof the reactor building and into tanks in the auxiliarybuilding, contaminating them. In addition, a small

amount of radioactivity was released into the atmo-sphere during efforts to relieve the pressure in thereactor containment building.

The accident at TMI caused no injuries or deaths, andat least a dozen epidemiological studies that have beenconducted since the accident have indicated no discernablehealth effects among the population around the site. Thereactor core and damaged fuel have been removed fromTMI Unit 2 and the reactor facility has been placed intomonitored storage and Unit 1 continues to operate andgenerate electricity. It is planned that both reactor facilitieswill be decommissioned jointly when Unit 1 eventuallycompletes its licensed operating lifetime. The accident at TMI profoundly changed the nuclearenergy industry and the NRC. All aspects of plantdesign, operations, and equipment reliability related tonuclear safety were substantially upgraded. Expandedcapabilities were put in place for accident prevention andmitigation, radiation monitoring and dose assessment,and emergency preparedness, including greatly en-hanced training, drills, and exercises to test and improveeach plant’s ability to respond to off-normal and acci-dent conditions. In addition, the nuclear industry formedthe Institute of Nuclear Power Operations (INPO) toprovide independent evaluation and oversight of plantnuclear and radiation safety, as well as to foster continu-ously improving standards of performance.

The installation of major modifications to plant safetysystems, structures, and components resulted in amarked increase in occupational dose in the yearsfollowing the TMI accident (1979-1985). However, theresulting challenges had an overall positive effect offacilitating the development of more effective ap-proaches to maintaining exposures as low as reasonablyachievable (ALARA), which was greatly enhanced byimplementation of the INPO programs for evaluationand sharing of operating experience. For its part, the NRC permanently increased thelevel and detail of regulatory requirements, oversight,and interactions with licensees. A significant follow-up action was the NRC Health Physics AppraisalProgram, in which the NRC sent teams of agencyhealth physicists to 48 nuclear power plants toperform detailed assessments of the adequacy ofradiation protection programs and to determine whetherTMI lessons learned were being effectively imple-mented. The extensive interactions between NRC andthe nuclear industry during the appraisal program alsohad the effect of indelibly highlighting the key impor-tance of the qualifications, training, roles, and responsi-bilities of the plant radiation protection staff and furtherbolstering industry efforts to reduce occupationalradiation exposure.


The dramaticpositive impact ofthe TMI accidentand its aftermathon nuclear powerplant radiationprotection isillustrated inFigure 1.

Post-TMIIn the post-

TMI era, licens-ing of nuclearpower plantsbecame muchmore complex,controversial, anduncertain. Theaddition of majorplant modifica-tions and newprograms and procedures, as well as constantly chang-ing requirements, endless contentions in licensing, andfrequent delays in regulatory decision making helpedskyrocket the costs of constructing and licensing intothe billions of dollars per plant. As a result, somecompanies slowed or delayed construction of partiallybuilt plants, while others cancelled their plants alto-gether. Nevertheless, the licensing process for mostplants continued, albeit at a snail’s pace.

The last nuclear power plant to go into operation wasWatts Bar Unit 1 in Tennessee, which was issued anoperating license on 7 February 1996. Recently, theTennessee Valley Authorityreinitiated the licensingprocess for the nearlycompleted Watts Bar Unit 2reactor and is consideringresumption of constructionon two units at theBellafonte site in Alabama.

License Renewal In March 2000, the NRCbegan to approve 20-yearrenewals of nuclear powerplants’ 40-year operatinglicenses. This allows thoseplants that have compileddetailed applications andundergone rigorous reviewto operate for a total of 60

years. Since then,the NRC hasapproved licenserenewals for 49nuclear reactors.To date, theowners of 99 ofthe 104 operatingnuclear units havedecided to pursuelicense renewal,and more areexpected tofollow suit (seeStatus of Plantssynopsis below).The net effect oflicense renewalsis expected toextend theaverage operatinglifetime of the

current reactors until about 2040, followed by a decadeof decommissioning. This would mean that two moregenerations of health physics staff and other nuclearworkers will be needed to support the existing nuclearpower plants—i.e., even without building new plants.

Power Uprates Nuclear power plants are licensed by the NRC tooperate at a set maximum power level for which thesafety of the plant has been demonstrated by analysisprovided in the license application. Utilities may apply tothe NRC for a license amendment to operate at an

increased power level ifthey can show that the plantcan operate safely at thehigher level. Such changesare called power uprates,which may be accom-plished by more preciseanalysis or by actualmodifications to the plantwith corresponding poweruprates of one to 20percent. Since the 1970s the NRChas granted more than 120power uprates for a total of5,640 megawatts, which isroughly equivalent tobuilding five new nuclearpower plants.

Figure 1

Status of Existing Plants andNew Plant Applications in the United States

Existing Plants• 104 currently operating units (20 percent of thenation’s electricity)• 99 reactors for which the decision has been made topursue license renewal• 49 reactors already approved for license renewal• More expected to follow suit

New Plants—COL Applications Submitted• 26 reactors• 17 applications (number of sites)• 13 to be colocated at existing sites• 4 to be at new sites


DecommissioningAt the end of its operating life, a nuclear power plant’s

reactor is shut down for the final time and the plantenters into decommissioning. The decision to perma-nently shut down can be the result of reaching the endof the operating period allowed by the license, or theplant may be shut down earlier for economic or otherreasons. Following the final shutdown of the reactor, thelicensee must offload all of the fuel from the reactor andcertify to the NRC that the fuel hasbeen removed. At that point, thelicensee is no longer authorized toreload the fuel or restart the reactor.

Nuclear power plant licensees havethree options for decommissioning aplant prior to seeking termination ofthe license. The licensee can proceeddirectly to DECON, in which all of the radioactivecomponents and materials are decontaminated and/orremoved for disposal. Once decontamination or removalfor disposal has been completed, the licensee enters intoa license termination process with the NRC, in whichthe licensee must demonstrate that radiation doses tomembers of the public resulting from any residualradioactivity at the facility will be less than 25 mrem peryear and ALARA. Once a license is terminated, then thefacility can be released for unrestricted use. (There areother regulatory criteria for restricted-use options, butthese options have not been used to date at nuclearpower plants.)

A second option is for the licensee to place the facilityin protective storage, SAFSTOR, for up to 60 years,which allows much of the radioactivity to decay awayprior to entering into DECON.

A third option, ENTOMB, involves encasing radioac-tive structures, systems, and components in a long-livedmatrix, such as concrete, for an extended period of timewith the intention of allowing the remaining radioactivityto decay to levels that are suitable for termination of thelicense with little or no additional decontamination. TheENTOMB option has been retained in regulation, but hasnot been implemented in either detailed regulatoryguidance or in practice.

Under the present NRC regulations for decommission-ing, 10 nuclear power reactors have been successfullydecommissioned and their licenses have been terminated.Fourteen reactor units are currently in SAFSTOR or areundergoing active decommissioning.

Current Status Today, 104 nuclear power power plants are providingabout 20 percent of the nation’s electricity. Plant perfor-mance is being sustained at a high level, with new records

being set for electrical output and capacity factor, whileproduction costs remain the lowest among sources ofelectrical generation in the United States. Indicators ofnuclear safety performance show a continuously improvingpositive trend and collective and individual radiation dosesto workers are at an all-time low.

Among other factors, consolidation of ownership andoperating responsibility into large generating companieshas been a major contributor to the current high levels of

plant performance. Thesecompanies have theorganizational depth,financial resources, andeconomy of scale toachieve significant im-provements to perfor-mance. The number of

nuclear generating companies overall has been reducedby about half since 1999.

New challenges continue to arise and be met, such as thereplacement and refurbishment of aging components,comprehensive programs for inspection, testing andmitigation of metallurgical issues, and significantly en-hanced and refocused security plans for responding topotential threats in the post-9/11 era. Other issues are beingmanaged effectively, but are still in search of lastingsolutions, such as used nuclear fuel management, volatilityin uranium prices, and low-level radioactive waste disposal. In sum, the age of nuclear power that began withseveral small and diverse reactors more than 40 yearsago has reached full maturity. Nuclear power is nowfulfilling much of its long-sought promise for safe,reliable, and economic energy produced in a manner thatis protective of the environment. Although new chal-lenges arise and are being met, the stage has been set forthe next chapter—new plants.

Outlook for New Plants Several factors have converged to foster a newinterest in expanding the use of nuclear energy in theUnited States. The demand for electricity continues toincrease. The costs and supplies of other fuel sourcescontinue to be uncertain. Concerns about clean air andclimate change continue to grow. And the deteriorationof the economy has given focus to new programs torevitalize the nation’s infrastructure and create lastingwell-paying jobs. In the energy sector, nuclear powercuts across all of these factors in a big way.

New Plant Licensing ProcessIn response to the Energy Policy Act of 1992, the NRC

created an improved one-step licensing process for newplants that includes issuing combined construction and

This would mean that two more genera-tions of health physics staff and othernuclear workers will be needed to sup-port the existing nuclear power plants—i.e., even without building new plants.


operatinglicenses (COLs),as illustrated inFigure 2. Mostimportantly, thenew processplaces theregulatoryreviews, resolu-tion of issues,and ultimateapproval at thefront end—priorto the outlay ofsignificantexpenditures.Thereby, the process minimizes regulatory risk, whilestill providing proper review and ample opportunity forpublic involvement.

New Reactor DesignsFive new reactor designs either have been certified or are

currently under regulatory review (see B in the ReactorDesigns synopsis on page 4). The new designs reflectevolutionary enhancements to the existing reactors, e.g., byreducing the overall number of pumps, valves, and othercomponents; employing passive safety features that rely onnatural processes (e.g., gravity); and including enhancedsafety and protection features (e.g., additional redundancy

and bunkeredsafety systems).The reactordesigns includethe GE advancedBWR (ABWR),the Westing-house advancedPWR (AP-1000), the GE-Hitachi eco-nomic simplifiedBWR (ESBWR),the AREVAEuropeanpressurized

reactor (EPR), and the Mitsubishi US-advanced PWR(US-APWR). The units are large—ranging from 1,150to 1,700 MWe (megawatt-electrical).

New Nuclear Power PlantsFrom 2007 to the present, 17 COL applications for 26

new reactors have been submitted to the NRC. Thirteenof the new plants would be colocated at existing reactorsites and four would be at new sites. Figure 3 shows thelocations and types for all of the new reactors beingconsidered, including some for which applications havenot yet been submitted. Initial construction of new plants is expected to start

in 2010, with the first plantsexpected to start up in 2016-2017. Only a few plants areexpected to comprise the firstwave of new plants, with moreto follow when the newprocess is proven to besuccessful, not only from thecurrent batch of applicationsfor the evolutionary BWRs andPWRs, but eventually toinclude the emerging advancedreactor designs, known asGeneration IV. But that’s another story.

Acknowledgement: Theauthor wishes to acknowledgethe wealth of useful informa-tion on the Web sites of theNRC (www.nrc.gov) andNuclear Energy Institute(www.nei.org) that helpedshape and inform this article.

Location of Projected New Nuclear Power ReactorsLocation of Projected New Nuclear Power ReactorsLocation of Projected New Nuclear Power ReactorsLocation of Projected New Nuclear Power ReactorsLocation of Projected New Nuclear Power Reactors

Figure 3

Figure 2


“It Takes a Village …”So goes the African proverb that provided the title and

inspiration for Secretary of State Hillary Clinton’s bookthat reflects the “commonsense conclusion that, like itor not, we live in an interdependent world.” In theintroduction to her book, Clinton notes that the phrasehas caught on in a number of other contexts such as “ittakes a village to have a parade,” “... to build a zerowaste community,” and “... to raise a pig.”

With due deference to African tribal wisdom andClinton, it seems fitting to adopt as a theme for thisarticle that it also takes a village to achieve radiationsafety at a nuclear power plant.

Clearly, a core group in this endeavor includes theplant radiation protection managers (RPMs), healthphysicists, radiological engineers, and radiation protec-tion (RP) technicians who are intensely focused onradiation safety. But the “village” also includes civil,mechanical, electrical, chemical, and nuclear engineers;reactor and power plant operators; mechanical, electri-cal, and instrument and control staff; chemists andchemistry technicians; security officers; welders; pipefitters; boilermakers; electricians; nondestructiveexamination and in-service inspection specialists;radiographers; scaffolders; insulators; painters; carpen-ters; and more.

Beyond the boundaries of the plant site, the corporate/fleet RP staff, along with their counterparts at theElectric Power Research Institute (research and develop-ment), Nuclear Energy Institute (policy and planning),Institute of Nuclear Power Operations (performanceevaluation and assistance), and American NuclearInsurers (risk management), form an essential part of thevillage. Last, but certainly not least, the village includesthe headquarters and regional health physics staff of theNuclear Regulatory Commission (NRC), who indepen-



This is the sixth in a series of articles in Health Physics News that provides an overview of nuclear power so thatthe effect of a resurgence of this energy source on the profession of health physics can be anticipated. The first five

installments (Health Physics News July, September, and November 2008 and January and March 2009) presented anoverview of nuclear power generation, the uranium recovery industry, the uranium conversion and isotopic enrichmentprocesses, the fuel fabrication process, and the first in the two-part story on the history, status, and outlook for nuclearpower in the United States. This second part on the outlook for nuclear power focuses on how radiation safety is fullyintegrated across all aspects of nuclear power plant design, licensing, construction, startup, operation, refueling andmaintenance outages, monitoring, emergency preparedness, and decommissioning and license termination.

Radiation Safety at Nuclear Power Plants

dently verify through oversight and inspection thatworkers, the public, and the environment are beingprotected.

The village model is especially apt because of the wayin which radiation safety has evolved at nuclear powerplants over the past 50 years. The dramatic progress incontrolling and reducing radiation exposures has been theproduct of effective sharing of experience and lessonslearned throughout the entire village, gained not onlyfrom successful innovations, but also from the school ofhard knocks. This tribal knowledge is compiled andhanded down through successive generations at anindividual plant, within a company, and across theindustry. It is also carried firsthand by the vitally impor-tant skilled craft workers and RP technicians who travelfrom plant to plant to support refueling outages and plantmodification projects.

In summary, it’s a big village—one that extends fromcoast to coast and includes hundreds of thousands ofprofessionals, spanning generations over the past 50years and another 50 or more into the future. This villagecollectively contributes to the continuing success inradiation safety at nuclear power plants by each memberdoing his or her job right every day in a commonendeavor to generate electricity safely, reliably, andeconomically.

The most enduring insight of our nuclear village is that“efficient generation of electricity and effective radiationsafety go hand in hand.” This critical relationship is welldemonstrated in Figure 1.

Preoperational Radiation SafetyIn many ways, the radiological destiny of a plant is

determined years before the first nuclear fuel bundlesarrive at the site, the reactor goes critical, and the plantgenerates electricity.


During the preopera-tional phases of design,licensing, and con-struction, thousands ofsmall and large deci-sions are made by amyriad of staff at thenuclear steam supplysystem vendor, thearchitect-engineeringfirm, the NRC, theconstruction company,and the operating utilitythat will define thesources, modes, andmeans of control ofradiation exposure toworkers and the public.

Although many of these decisions are not directlyrelated to radiation protection or health physics, theircumulative impact on the radiation safety challenges andopportunities that will be presented during the lifetime ofthe plant is profound.

DesignAs the saying goes, “an ounce of prevention is worth

a pound of cure.” This is certainly the case in regard tothe effect that the design of a nuclear power plant hason preventing accidents, reducing the potential forunplanned radiological releases, minimizing radiationdose, and facilitating decommissioning.

The underlying philosophy in a nuclear safety designis “defense-in-depth.” Overlapping and redundant safetysystems and protection capabilities provide assurancethat the likelihood of a reactor accident that would resultin off-site consequences is vanishingly small. Highlytrained and qualified operations and maintenance staffcontinuously monitor and test those systems andcapabilities to verify their availability and effectiveness.Overlying this preventative and protective framework isa comprehensive emergency-response program, inwhich plant personnel relentlessly drill and practice tobe able to respond 24-7 to every conceivable event,including participation in full-scale exercises with off-site medical, fire, police, and other emergency-responseorganizations, agencies, and officials.

The plant is designed to withstand the effects ofnatural phenomena, such as earthquakes, hurricanes,tornados, floods, and tsunamis, as well as to provideprotection for other events, such as the loss of off-sitepower (e.g., electrical blackouts), fires, and terroristattacks. Independent and physically separated protectionand control systems assure that the reactor can be

safely shut down andcooled. Multiple fissionbarriers to preventuncontrolled releasesof radioactivity includethe fuel cladding, thereactor vessel, thereactor coolantpressure boundary,and a thick, steel andconcrete containmentdesigned to be essen-tially leak tight underall postulated accidentconditions. Nuclear powerplants are designed to

control and minimize radiological releases to the environ-ment. Extensive waste-processing systems are installedto provide for storage and holdup (for radioactive decay)and filtration of gaseous and liquid effluents such thatthe radiation dose from releases during routine opera-tions, including anticipated transient conditions, will beALARA (as low as reasonably achievable). The reactorcontainment, in conjunction with emergency spray-down and filtration systems, is designed to delay andreduce releases from postulated accidents to allow timefor the taking of on-site and off-site protective actions(e.g., sheltering, evacuation, or administration of potassiumiodide) and to minimize potential radiation dose.

Plant design plays a key role in maintaining occupa-tional radiation dose ALARA. Radiological engineers andhealth physicists provide significant input and support,but success in this area hinges largely on assuring thatthe design and system engineers and specialists aretrained and knowledgeable on the design concepts andstation features that will ultimately reduce workerexposures. Examples of such concepts and featuresinclude providing means for controlling access toexpected radiation areas; effective use of permanentshielding (as well as facilitating use of temporaryshielding); proper selection of materials in systems andcomponents (e.g., to minimize activation products fromerosion, corrosion, and wear); laying out and designingplant systems and components in a way that minimizesthe need to access or spend time in radiation areas foroperation, maintenance, or testing; providing an exten-sive and adaptable plant radiation-monitoring system;and designing ventilation systems and contamination-control features to minimize the potential for airbornecontaminants and gaseous radiation sources.

The plant design is also required to facilitate eventualdecommissioning by minimizing the potential for con-

Figure 1


tamination of the facility and the environment and thegeneration of radioactive waste. Key design objectives inmeeting this requirement include features that (1)prevent and contain leaks or spills, (2) provide forprompt detection of leakage or contamination, and (3)facilitate decontamination and remediation. In addition,the plant is designed to facilitate dismantlement orremoval of structures, equipment, or components thatwill require replacement or removal during facilityoperation or decommissioning.

LicensingThere are two major elements in licensing a nuclear

power plant: a design certification (DC) and a construc-tion and operating license (COL). Some applicants haveopted to separately resolve site-related issues through theearly site permit (ESP) process, rather than through theCOL process. Each part of the process also requires anenvironmental impact statement (EIS).

The overall objective of the combined process is toconclude with “reasonable assurance” that a nuclearpower plant of a specific design at a specific site will beconstructed, operated, and decommissioned safely, thatthe health and safety of workers and the public will beprotected, and that there will not be a significant impacton the environment.

In this process, the applicant has the burden of proofto provide all of the necessary information. The NRCstaff is responsible for independently reviewing, verify-ing, and assessing the applicant’s information, as well asinformation provided by others, to decide whether areasonable assurance conclusion can be reached. At keypoints in each process, the NRC notifies all stakeholders(including the public) as to how and when they mayparticipate.

A DC is approved by the NRC through a rulemaking,in which a nuclear power plant design is approvedindependent of a specific operating company or site. Theapplicant must provide technical information to showthat the plant design meets all of the applicable regula-tory standards, including the nuclear and radiation safetycriteria described in the previous section. In addition, theapplication must describe in detail how key designfeatures will be verified during construction—known asinspection, test, analysis, and acceptance criteria(ITAAC). Radiation safety ITAAC topics include shield-ing, ventilation, and radiation-monitoring systems.

A COL is issued by the NRC to authorize a specificlicensee to construct and operate a specific-designnuclear power plant at a specific site. In a COL applica-tion, the NRC staff reviews the applicant’s qualifica-tions, design safety, environmental impacts, operationalprograms, site safety, and verification of construction

with ITAAC. In the area of health physics, the emphasisis on source term and radiological releases during routineoperations and postulated accidents, emergency pre-paredness, and operational programs related to radiationsafety. To facilitate licensing, the nuclear industry hasdeveloped standard operational programs for radiationprotection, ALARA, radiological effluent and environ-mental monitoring, solid radioactive waste processing,and life-cycle planning for minimization of contaminationand radioactive waste generation.

Companies may opt to seek approval for a specific sitefor a nuclear power plant, independent of a specificdesign, through an ESP. In reviewing an ESP application,the NRC staff reviews site safety issues, environmentalprotection issues, and plans for coping with emergen-cies. To date, three ESPs have been issued and one isunder review. Most companies are seeking approval oftheir respective sites through the COL process.

Applicants for a DC, COL, or ESP are required tosubmit an environmental report that describes andevaluates potential environmental impacts of site prepara-tion, construction, and plant operation and decommis-sioning and dismantlement. Health physics aspectsinclude the source term, radioactive waste-processingand radiation-monitoring systems, the radiological impactfrom routine operation and postulated accidents, and theradiological effluent and environmental monitoringprograms, including a preoperational environmentalmonitoring program. For each regulatory process (DC,COL, and ESP), the NRC issues a corresponding EISwhen the agency has determined that there will be nosignificant impact on the quality of the environment.

The COL review process is estimated to take aboutfour years. With the issuance of a COL, a licensee isauthorized to begin construction and eventually operate aspecific-design nuclear power plant at a specific site for40 years—and potentially extend the operating period foran additional 20 years.

ConstructionCompanies can be authorized to begin some prelimi-

nary site-preparation activities prior to receipt of theCOL, but the full construction project commences withissuance of the license. Although considered to still bewithin the preoperational phase, the four-year construc-tion period marks the transition period when staff isbeing hired, trained, and qualified; operational programprocedures are being written and tested; and equipmentand instrumentation is being purchased, installed, andmade ready for use. This is especially the case forradiation safety.

As part of the construction process itself, the ITAACmust be completed to verify that the plant is being built


and will operate as designed—including the radiationsafety-related ITAAC for shielding, ventilation, radiationmonitoring systems, etc. From day one of being as-signed to the new plant organization, RP personnelinvolve themselves in numerous design and constructiondetails to make sure that future operations and mainte-nance work can be performed in a manner that isALARA, that physical control over access to radiationareas can be effectively implemented, and that the layoutof radiation-protection facilities will be efficient. Also, theconstruction project has its own need for radiation safetyto address sources that are used during site preparationand construction activities, such as soil density testingand pipe weld radiography.

There are also elements of the operational program thatare required to be implemented during construction andprior to startup of the new plant. A preoperationalradiological environmental monitoring program must beimplemented at least two years prior to plant startup toestablish baseline measurements. To address groundwa-ter protection, a site conceptual model for monitoringsubsurface groundwater flow must be developed, alongwith a detailed description of the final postconstructionsite configuration, including underground piping andstructures.

The operational radiation safety program is imple-mented in phases during construction, with majormilestones at the point of ordering and receiving test andcalibration sources under the COL, as well as the initialreceipt of nuclear fuel.

Light water reactors use uranium fuel in the form ofceramic-like pellets contained in zircaloy-cladded tubularrods housed in a fuel assembly (see Health Physics NewsJanuary 2009). When new fuel is received at the site, itis inspected, surveyed, and placed into storage until it isloaded into the reactor. New fuel poses a minor sourceof direct gamma exposure and may have minute amountsof uranium contamination on the outside surface of thefuel rods remaining from the manufacturing process(referred to as “tramp” uranium).

If the new plant is being constructed at a site with anoperating nuclear power plant, then dose to the con-struction workforce from radiological effluents anddirect radiation from the neighboring plant needs to bemonitored. Also, soil excavation may need to be moni-tored if there is a potential for residual contaminationfrom operation of the neighboring plant.

When construction is complete and verified and allconditions of the COL have been met, transition frompreoperational to operational occurs with the loading ofnuclear fuel into the reactor. At that time, the radiation-protection program must be fully implemented, includinga complete complement of trained and qualified radiation-

protection staff and fully operational radiation-protectionfacilities, instrumentation, and equipment.

Operational Radiation SafetyRadiation Protection Organization

The overall responsibility for maintaining safe opera-tion of a nuclear power plant, including radiation safety,rests with the plant manager. The plant manager is theone who balances priorities, approves goals and objec-tives, and allocates resources, and therefore it is the plantmanager who assures the essential support of the RPMby the entire plant organization to implement an effectiveradiation safety program. Typically, a plant managerestablishes and chairs a plant ALARA committee,including the RPM and other department managers, toprovide effective cooperation and coordination acrossthe site organization to set and meet challenging ALARAgoals and objectives. Experience has shown that to betruly successful, the program must be owned byeveryone and not just enforced by the RP organization.

The RPM and the 20 to 40 health physicists, special-ists, and technicians who make up a plant’s RP organiza-tion provide the leadership, technical expertise, and oftenthe conscience to help the plant organization maintain ahigh level of vigilance in dealing with the daily challengesof working in a radiological environment and respect forthe need to comply with all of the RP procedures andgood practices that prevent unplanned exposures,contamination, or releases of radioactive material.

The RP organization carries out a number of special-ized functions, including personnel dosimetry, bioassay,respiratory protection, instrument calibration andmaintenance, and radioactive source control. Control andmonitoring of radiological effluents, environmentalmonitoring, and processing, packaging, and shipping ofradioactive waste may be carried by the RP staff or be ashared or supported responsibility of the plant chemistryand operations organizations.

Radiation workers get dressed out for work in the plant.


The “face” of theRP organization (ifnot the heart andsoul) as seen by therest of the plantworkforce is thehighly trained,qualified, andexperienced RPtechnician whoconducts radiologi-cal surveys and assessments, participates in workplanning, establishes radiation-protection requirements,and provides oversight and monitoring for jobs involvingradiation exposure. A unique and vital responsibility thatis borne by each RP technician is to stop work or orderan area evacuated when, in his or her judgment, theradiological conditions warrant such an action (whensuch action does not compromise nuclear safety). Thiscalls for a special set of capabilities and qualities that arerare—even within our health physics community that isfounded on high standards of professionalism and ethics.

Reactor-Related Radiation SourcesWhen nuclear fuel is loaded into the reactor and

undergoes fission, it produces significant quantities offission products, including noble gases (krypton andxenon), radioiodines, cesium, strontium, tritium, andactinides (uranium, plutonium, neptunium, americium,and curium). Materials in the fuel cladding and assemblyitself become neutron-activated, including zirconium,niobium, cobalt, and other metals.

When the fissionable material in nuclear fuel is ex-pended to a level where it is no longer efficient for use,the fuel is removed from the reactor and stored under-water in a spent-fuel pool to allow radioactive decay ofshorter-lived fission products and cooling off (ther-mally). After five or more years, the used fuel may bemoved from the spent-fuel pool to dry storage inshielded canisters within an on-site interim spent-fuelstorage installation (ISFSI).

During reactor operation, the fission products andactinides are largely contained within the fuel rods,although small amounts may be released into the reactorcoolant water through pinhole-size leaks in the claddingmaterial, as well as from the fission of tramp uranium onthe external surfaces of the fuel rods. In addition,erosion and corrosion processes introduce smallamounts of activated materials into the reactor coolantwater from the fuel cladding and assemblies, as well asfrom other reactor internal components.

Several radionuclides are produced by neutron interac-tions with the reactor coolant water when it passes

through the reactor. Tritium is produced as a result ofneutron reactions with boron that is added to the coolingwater at pressurized water reactors (PWRs) for reactiv-ity control and lithium added at boiling water reactors(BWRs) for chemistry pH control. 14C is produced byneutron interactions with oxygen and nitrogen in thewater.

Neutron reactions with oxygen in the water produce16N, which emits a high-energy gamma ray (>6 MeV).Despite its very short half-life, 16N that is carried fromthe reactor into the steam supply system and turbine isthe primary source of direct radiation exposure in theenvirons around a BWR due to skyshine. Therefore,BWR plant turbine buildings are designed with concreteshielding to maintain radiation levels at the site orrestricted area boundary within the dose-rate limits setby the NRC.

16N is a primary source of external exposure, alongwith neutron radiation, within a PWR reactor contain-ment or a BWR dry well when the reactor is in poweroperation. Although it is not routine, plant personneldo occasionally enter the containment or dry wellwhile the reactor is operating to perform a requiredsurveillance or inspect or repair a component. 16N isalso a significant source of radiation exposure in areasof the plant where piping that transports steam to theturbine is located.

A dominant source of radioactivity in a nuclear powerplant comes from the neutron activation of metalparticles that result from erosion, corrosion, and me-chanical wear processes in the piping, pumps, and valvesin the various circulating water systems in the plant,when the particles pass through the reactor while it iscritical. Primary activation materials include radioiso-topes of cobalt, nickel, chromium, manganese, zinc, andiron.

Over time, the activated materials, along with traceamounts of fission products and actinides, are circulatedthrough the plant reactor coolant system and, at BWRs,through the steam supply system, where they plate outon piping surfaces or in pumps, valves, or other compo-nents and become a primary source of direct gammaexposure and create a potential source of surfacecontamination or airborne radioactivity when plantsystems and components are opened for inspection,testing, and maintenance during outages.

Reactor StartupReactor startup includes loading nuclear fuel in the

reactor, reaching initial criticality, and then increasingreactor power through successive stages during whichextensive testing is conducted of the reactor system,safety systems, the steam supply and electrical genera-

Radiological Monitoring System ControlRoom at the San Onofre Nuclear Gener-ating Station


tion system, and auxiliary systems. The start-up testingphase lasts for four to six months, culminating inconnecting the plant to the electrical grid and commenc-ing commercial operation.

During the start-up phase, the RP staff is focused onunderstanding the baseline radiological conditions in theplant and adjusting operational aspects of the RP pro-gram to fit the routine work processes of the plantorganization. A major effort during this phase includesconducting extensive surveys throughout the plant ateach power level to verify shielding effectiveness and putmeasures in place to monitor and control access toradiation areas.

There are also many opportunities to instill goodradiological work practices during operator rounds andsurveillances and when systems or components areopened up for inspection, testing, or maintenance. Anessential element of planning and executing thesework activities is the establishment of shared expecta-tions between the RP staff and plant workers—i.e.,team building to achieve a common goal of radiationsafety.

Reactor OperationReactors are operated for 18- to 24-month periods—

limited by the time during which the nuclear fuel canefficiently be used to produce power without the needfor rearranging the fuel within the reactor core orreplacing used fuel with new fuel. Primary work activi-ties that occur in the plant during reactor operationinclude operator rounds; routine inspection, testing, andcalibration of equipment; and some preventative mainte-nance on systems and components that can safely betaken out of service. Also, RP technicians performcontinuous monitoring and surveys to confirm thatradiological conditions haven’t changed and radiationareas are properly posted and controlled.

Plant personnel do not routinely access areas withsignificant levels of radiation or contamination, andconsequently, radiation doses during reactor operationare low. The total collective radiation exposure for aplant during the 18- to 24-month operating period istypically less than 10 person-rem (0.1 person-Sv).

Occasionally, a problem may arise with an essentialcomponent or safety-related equipment that requirespersonnel to enter the reactor containment while thereactor is operating or areas of the plant where steamis circulating through the piping and higher radiationlevels (e.g., related to neutron radiation or 16N) maybe encountered. In such cases, the entry into the areaand potential work to be performed is carefullyplanned and executed to minimize the number of peopleand time spent in the area. If necessary, the reactor

power may be reduced or the plant may be shut downfor a brief period to allow for the work to be done withreduced radiation exposure.

A major effort that occurs during power operation isgetting ready for the next refueling outage. The relativecalm during plant operation allows for all of the neces-sary resources to be brought to bear on developing anoutage plan and schedule, staging and arranging for allthe necessary people and materials, and carrying out adetailed review of each job to incorporate lessons learnedfrom previous outages and plan new innovations to makesure that worker exposures will be ALARA.

Refueling and Maintenance OutagesThe oft-repeated principle for a successful refueling

outage is to “plan the work and work the plan.” Thesubstantial investment of time and resources during the18 to 24 months of operation pays off during carefulexecution of a precisely planned 4- to 12-week outage(the duration is dependent on the scope of necessarymaintenance or special projects, such as modifications toimplement an approved power uprate). This is especiallytrue of ALARA planning that is carried out at a task-by-task level.

In advance of the outage, additional RP technicians(typically 40-80) are brought in to supplement the plantRP staff. They are trained and qualified on specificprocedures and equipment used in the plant and areintegrated into the RP team for the outage. As an addedvalue, these technicians often bring recent experienceand lessons learned from other outages that may beincorporated into the current outage plan.

Many of the RP staff are focused on engaging with theincoming workforce of 500-1,000 people to acquire doserecords, issue dosimetry, perform whole-body counts,conduct radiation-worker and respiratory-protectiontraining, as well as joining up with the various workteams to finalize ALARA plans and radiation workpermits, conduct prejob briefings, and get to know theirteammates.

As the shutdown of the reactor approaches, finalstaging and preparations are completed for installation oftemporary shielding and portable ventilation enclosures,decontamination equipment and supplies, supplied-airlines and respirator units, temporary access and workcontrol points, remote communications and monitoringequipment, etc. All members of the RP team review andrereview what they need to do and where and when theyneed to do it following shutdown.

For a plant outage, the operators and RP techniciansare the first in and the last out. As soon as the reactor issafely shut down and secured, the RP technicians enterareas to be accessed during the outage, conduct radiation


surveys, set posting and access controls, and triggerplans for temporary shielding, decontamination, enclo-sures, etc., that need to be in place for the outage workto begin—which is a major campaign that needs to beaccomplished in a very short time. For example, manytons of temporary lead shielding are typically installedduring an outage.

An outage typically is divided into three parallel efforts:refueling; testing, inspection, and maintenance; andspecial projects. RP resources are usually aligned tosupport each of these efforts, assigning staff to therefueling floor, to areas of the plant for coverage ofinspection, testing, and maintenance, and as integralmembers of the teams performing special projects. AnRP management team oversees and coordinates RPsupport between the various activities and interfaceswith the outage management team. The outage isconducted around the clock and more often than not iscompleted within the schedule, budget, and radiation-dose goals set for the outage.

As outage work and refueling comes to completion,the first days’ activities are repeated, except in reverse—all the shielding, equipment, and materials must beremoved and accounted for, postjob briefings are held tocapture lessons learned for the next outage, and theoutage workforce is outprocessed (e.g., performing exitwhole-body counts and dosimeter processing andcompleting dose records).

Once the plant is restarted and operating, planningbegins for the next refueling outage.

Radiological Effluents and Environmental MonitoringAs a routine part of nuclear power plant operation,

gaseous and liquid effluents are released to the environ-ment—at levels that are well below the radiation safetystandards set by the NRC and the Environmental Protec-tion Agency. In fact, nuclear power plants are required tomaintain effluent releases to the environment at levelsthat are ALARA, which equates to doses that are esti-

mated to be on the order of 0.01 mSv y-1 or less to ahypothetical maximally exposed individual at the siteboundary.

Prior to being released, the effluents are processedthrough waste treatment systems that provide for holdupand decay of shorter-lived radionuclides and filtering outof most of the radioiodines and particulates in charcoal,ion-exchange resins, and mechanical filter cartridges.The primary radionuclides that are ultimately releasedfrom a plant include noble gases and tritium (as HTOvapor) in gaseous effluents and tritium in liquid effluents.Trace quantities of radioiodines and particulate radionu-clides may also be present.

Radiological effluents are continuously monitored andare periodically sampled to make sure that radiationmonitors are properly calibrated for monitoring therespective mixture of radionuclides in the effluents.Radiation monitors also include set points that actuate analarm to alert plant operators to take action prior to anyrelease criteria being exceeded.

Each plant maintains an offsite dose calculation manual(ODCM) that contains specific criteria for monitoringand sampling radiological effluents and a detailed meth-odology for estimating off-site radiation doses. Doses arecalculated for each release (or continuous releasepathway) and are projected to ensure that all monthly,quarterly, and annual release criteria will be met. Everyyear, each plant prepares and submits a public annualradioactive effluent release report to the NRC thatincludes the quantities of principal radionuclides releasedin gaseous and liquid effluents, calculated radiation dosesto the public, and supporting information needed tovalidate the calculations.

Plants also conduct a separate radiological environ-mental monitoring program (REMP) that begins prior tooperation of the plant and continues throughout itsoperating lifetime. The objective of the program is todetermine if any measurable levels of radiation orradioactive materials in the environment are attributableto operation of the plant and if the levels are consistentwith what has been released from the plant. A typicalprogram includes nearly 1,000 sampling results a year ofdirect radiation, air, surface and underground water,sediments, vegetation, milk, fish, and any other mediathat is representative of dose pathways for humans.

The REMP also includes an annual land-use censusthat consists of surveys of areas around the plant to seeif there have been any changes to agricultural land use,residences, water use, dairy farms, or other activitiesthat might affect the methodology for calculating dosesto the public (i.e., in the ODCM).

Every year, each plant prepares and submits a publicannual radiological environmental operating report to the

Lake-water sampling at the Comanche Peak NuclearPower Plant


NRC that includes all of the results of the environmentalsampling program and the land-use census.

Emergency PreparednessEmergency response plans are required by federal law

and regulations to be implemented at each nuclear powerplant. The plans involve not only the company operatingthe plant, but also local, state, and federal officials andemergency-response organizations, law enforcement andfire depart-ments, andlocal hospi-tals. Emer-gency-responseplans remainin effectduring theoperatinglifetime of theplant andthroughdecommis-sioning until termination of the license.

Nuclear power plant emergency-response plans utilizetwo emergency planning zones (EPZ) in their develop-ment. A 10-mile radius EPZ is used to plan immediateprotective actions for the surrounding population,including sheltering, evacuation, and the distribution andadministration of potassium iodide. A 50-mile radius isused to plan actions to protect the public from exposureto radioactive material from consumption of food, milk,and water should an event occur.

The plans are tested every two years in a full-scale,integrated exercise that is based upon a confidentialscenario that is not known in advance to the participants.Extensive training and numerous drills and tests areconducted between the biennial exercises to assure thateveryone is qualified and ready to respond to an event.After each of the drills and exercises, the auditors andparticipants participate in formal critiques that are usedto identify and incorporate improvements and correctiveactions.

Members of the RP staff maintain many of the plant’semergency-response capabilities, including plant radiationand effluent monitoring systems, dose-assessmentprograms, and equipment for protecting plant personnelduring emergencies. They also fulfill key functions in theemergency-response organization, such as monitoringradiological conditions in the plant and off-site, project-ing doses to the public and recommending protectiveactions, and providing direct radiation-protection supportfor a wide range of emergency-response activities.

It has been estimated that during a working career at aplant, a health physicist or technician participates in wellover 100 emergency exercises and drills.

Decommissioning and License TerminationIn many ways, radiation safety is more challenging

during the deconstruction of a nuclear power plant thanduring its construction and operation.

Systems and components that serve to containsources of radiation exposure during operation aredisassembled, segmented, and packaged for shipmentto a disposal site. Structures that provide shieldingand physical control of access to radiation areas aredismantled or demolished. Also, many tasks aresufficiently unique as to require detailed planningfrom the ground up, rather than being routine evolu-tions for which each repetition provides an opportu-nity to apply lessons learned and implement increas-ingly effective radiological controls.

Thesefactors leadto a greaterpotential forhigher levelsof radiation,contamina-tion, andairborneradioactivityassociatedwithdecommis-sioning, as well as an increased probability of encounter-ing novel or unexpected situations.

For these reasons, operational RP programs need to beadjusted for decommissioning, especially in regard todetection and monitoring of alpha contamination, internaldose monitoring and assessment, containment andventilation controls, and training of workers and RPstaff.

In addition to the deconstruction aspect, decommis-sioning presents differences from operation in terms ofthe much larger scale of shipping radioactive waste andconducting radiation surveys.

The volume of radioactive waste shipped during adecommissioning is orders of magnitude higher than thatat an operating plant. The total volume can range up toseveral million cubic feet of radioactive waste during afive- to seven-year period. Although the vast majority ofthis waste is very low level, there are challengingshipments such as reactor vessels, steam generators,and segmented reactor vessel internals. Even when thiswork is not directly managed by the RP department, the

Concrete core sampling at Connecticut Yankeedecommissioning

Vermont Yankee personnel conduct a medicaldrill with the local ambulance service.


RP staff needs to provide extensive support for thepackaging and surveys of these shipments.

Decommissioning also involves several unique radia-tion survey projects, including a historical site assess-ment, site characterization, and a final status survey.The historical site assessment includes an exhaustivereview of site records and interviews with current andprevious site staff to identify potential locations ofresidual radioactivity and an assessment of how residualradioactivity may have migrated to other locations. Italso identifies situations that will require special surveys,such as subsurface radioactivity, sewer and storm drainsystems, ventilation ducts, and embedded piping. Theresults of the historical site assessment serve as input todesigning the characterization survey.

The site characterization survey typically followscompletion of dismantlement and decontaminationactivities, in which the majority of radioactive wastehas been shipped for disposal. The survey determinesthe type and extent of residual radioactivity at the siteand forms the basis for a license termination plan toremediate the site and conduct a final status survey.

The final status survey demonstrates that anyremaining residual radioactivity meets the criteria for

terminating the license and releasing the site forunrestricted use (note that nuclear power plants todate have not pursued restricted-use options). Thesurvey is comprehensive and includes total surfaceactivity, removable surface activity, direct exposurerates, and concentrations in soil, water, and othermedia.

In conjunction with or following license termina-tion, additional actions may be taken to bring the siteto a greenfield status by remediating nonradiologicalcontaminants, removing structures and equipment,landscaping, etc.

At present, decommissioned sites still have anISFSI to provide safe and secure storage of usednuclear fuel until a disposal or other disposition optionis made available.

This remaining step in the fuel cycle will be the topicof a future (and final) article in this series.

Acknowledgement: The author wishes to acknowledgethe valuable input and advice provided by Roger Shaw(K&L Gates LLP) on emergency preparedness andRichard McGrath (Electric Power Research Institute) ondecommissioning.


The Resurgence of Nuclear PowerThe Resurgence of Nuclear PowerThe Resurgence of Nuclear PowerThe Resurgence of Nuclear PowerThe Resurgence of Nuclear PowerImpact on the Health Physics Profession


This is the seventh and final installment in a series of articles in Health Physics News that provides an overview ofnuclear power so that the effect of a resurgence of this energy source on the profession of health physics can be

anticipated. The previous six articles (Health Physics News July, September, and November 2008 and January, March,and September 2009) have presented an overview of the different elements of nuclear power generation, includinguranium recovery, uranium conversion and isotopic enrichment, fuel fabrication, and nuclear power plant design,construction, operation, and decommissioning. This final article in the series covers the so-called back end of the fuelcycle—the ultimate disposition path for irradiated nuclear fuel.

As you will read in this article, the path contains a number of options and no small amount of uncertainty aboutwhich options may be selected. As with our previous articles in this series, we are fortunate to have an author,Andrew Sowder, PhD, CHP, who is an expert on the subject matter. In light of the fluidity of our own national policyon used nuclear fuel management, Health Physics News Editor-in-Chief Gen Roessler and I encouraged Sowder toconvey his own well-informed views on how the political and sociological challenges associated with the developmentof a national used nuclear fuel management policy may play out, in addition to providing us with an in-depth under-standing of the underlying science and technology of this issue.

Andrew Sowder, PhD, CHP

Used Nuclear Fuel Management: The Back End of the Fuel Cycle

IntroductionThe termination of the Yucca Mountain program

moves the construction and operation of a high-levelradioactive waste (HLW) repository in the United Statesinto the future once more. This development reinforces abelief among some that there is no answer to the ques-tion of what to do with the nation’s used fuel from itscommercial nuclear power plants. The “no solution tothe waste problem” refrain is often cited as a primaryargument against continued use and expansion of nuclearas a source of carbon-free electricity. And while recentpolling has indicated public support for nuclear energyhas returned to levels not seen in decades, the subject ofused nuclear fuel continues to figure heavily into thepublic’s view of nuclear.1

From a technical perspective, the “no solution” refrainignores the international scientific consensus developedover the past five decades that deep geologic disposal ofused fuel and HLW in a suitable geologic formation canprovide adequate protection of the environment andhuman health over sufficiently long time frames, i.e.,thousands to hundreds of thousands of years.2 To thisend, most countries seriously pursuing a nuclear wastemanagement strategy have chosen deep geologic disposal

as the approach of choice for managing inventories ofused nuclear fuel and/or residual high-level wastesarising from reprocessing. Efforts to site such facili-ties invariably present social, political, economic, andtechnical challenges and require slow, deliberate, anddifficult decision-making processes. As inventories ofused nuclear fuel have accumulated in many coun-tries, dry storage is increasingly seen as a necessaryintermediate step in the nuclear fuel cycle (Figure 1).Depending on your point of view, dry storage can beseen as a prudent step that will allow for the UnitedStates to make key decisions regarding the ultimatepath for used fuel (as a waste or resource) or as aninterim measure until a permanent geologic repository isoperational.

Through the Nuclear Waste Policy Act (NWPA) of1982, the U.S. Department of Energy (DOE) selecteddeep geologic disposal of used nuclear fuel and HLW ina mined repository as the technology of choice. The Actrequired electric utilities (and their customers) to pay1/10 of a cent per kW-hr of nuclear power generatedinto a Nuclear Waste Fund to cover the cost of therepository program. Contributions to the Fund andinterest now exceed $33 billion. For its part, the federal

1 2009 results of an industry tracking poll of nuclear plant neighbors. Bisconti Research, July 2009, http://www.nei.org/resourcesandstats/documentlibrary/newplants/reports/third-biennial-nuclear-power-plant-neighbor-public-opinion-tracking-survey.2 This international technical consensus has its roots in a 1957 report issued by the U.S. National Academy of Sciences titled “The Disposal ofRadioactive Waste on Land.” National Research Council, Publication 519, National Academies Press, Washington, DC; 1957.


government agreed to begin removing used nuclear fuelfrom commercial reactor sites beginning in 1998—acontractual timeline explicitly incorporated in a formalarrangement between the government and nuclearutilities known as the Standard Contract for disposal ofcommercial used fuel. The NWPA also called on DOE todevelop plans for transportation and for interim storageof used nuclear fuel if needed, called for siting of asecond repository, and set a waste inventory cap of70,000 metric tons of heavy metal (MTHM) for the firstrepository until the second was operational (League ofWomen Voters 1993). In 1983, DOE selected ninecandidate sites (comprising five distinctgeohydrological environments in six states) with theintent of narrowing the field to five for furthercharacterization and submitting three finalists forPresidential approval for full-scale characterization.The three finalists were sites at Hanford, Washington(basalt), Yucca Mountain, Nevada (tuff), and DeafSmith County, Texas (bedded salt). Amendment to thelaw in 1987 narrowed the evaluation of appropriatehost sites from three to one: Yucca Mountain, Nevada.Congress and the Bush Administration formallyapproved Yucca Mountain in 2002 as the first nationalrepository site following DOE confirmation of the sitesuitability. DOE submitted a license application forconstruction of the repository to the U.S. NuclearRegulatory Commission (USNRC) in June 2008. Inearly 2009, the new Obama Administration indicatedthat “nuclear waste storage at Yucca Mountain is not anoption”3 and accompanying policy shifts have effectivelyterminated the Yucca Mountain program, although the

licensing process has continued. This major shift in U.S.waste policy has been accompanied by an ExecutiveBranch proposal to establish a blue-ribbon commissionthat would reevaluate the options for managing the U.S.inventory of commercial used nuclear fuel.

Societal IssuesIf there is a technical solution, what then is the

problem? Simply put, social and political factors heavilyimpact siting decisions for a facility like a geologicrepository. In the United States, two decades of sitecharacterization and associated research have resulted inthe description of Yucca Mountain as “the most studiedreal estate on the planet” (U.S. Senate Committee onEnvironment and Public Works 2006). Yet, the reposi-tory program faces termination before the licenseapplication has been fully reviewed largely due topolitical opposition from the state of Nevada, which hassteadily grown in intensity since the narrowing fromthree candidate sites to one took place with the passageof the 1987 NWPA amendments.

Some of the key social and political obstacles andchallenges presented by the siting and design of a geologicrepository for disposal of used fuel and HLW are:• Unprecedented regulatory compliance periods forgeologic repositories (10,000 to 1,000,000 years) that farexceed the recorded history of humans on Earth andexpectations of institutional control.• Public distrust of government agencies and programsthat have roots in secrecy, such as the nuclear weaponscomplex.• Intragenerational, geographical, and procedural equity,i.e., the challenges presented when one geographicregion, generation, or social group assumes a burden thatit did not benefit from in relation to the costs or otherimpacts.• National decisions on the value of used nuclear fuel asa resource versus a waste and reversibility of any sitingand design decisions should policy change.• Responsibility on generator of wastes for dealing withwastes (polluter pays principle) balanced against theethics of restricting options for future generations,including the option to use the irradiated fuel as anenergy resource.

These issues and more must be balanced and ac-counted for in a transparent selection process that

3 26 February 2009 release of administration’s draft budget reveals severe cuts to Yucca Mountain program; DOE press secretary announces “nuclearwaste storage at Yucca Mountain is not an option.” 5 March 2009—Energy Secretary Steven Chu’s remarks at Senate hearings confirm the “not anoption” position and suggest “blue ribbon commission” formation.4 Used nuclear fuel is stored underwater in lined concrete basins to provide cooling and shielding immediately after it is removed from the reactor core.After sufficient time has passed to allow for decay of the shorter-lived radionuclides responsible for much of the initial heat load (on the order of fiveyears for uranium oxide fuel), used fuel can be moved into dry storage with cooling provided by natural convection of ambient air and shieldingprovided by the engineered container system (typically concrete or steel).

Figure 1. Dry storage of used fuel4 (Source: USNRC)


dovetails with the technical elements ofthe repository program.

There are positive examples for thesite-selection process of a geologicrepository that have negotiated or appearlikely to successfully negotiate theformidable challenges. The WasteIsolation Pilot Plant (WIPP) nearCarlsbad, New Mexico, is currentlyoperational, accepting transuranic wastesfrom U.S. defense programs after beingcertified by the U.S. EnvironmentalProtection Agency (EPA) under itsauthority in 40 CFR 194. More recently,voluntary participation of communities inSweden (motivated in part by economicbenefits and government incentives) in acompetitive site-selection processresulted in the successful selection of acandidate-used fuel repository site at Forsmark. Ap-proaches that focus on building genuine local andregional support among the public and politicians earlyin the process may offer the greatest promise forconstruction and operation of a deep geologic repositoryfor used nuclear fuel or HLW in the early 21st century.

There Is a Solution for the Waste ProblemWhy is there broad international scientific consen-

sus that the solution for disposal of used nuclear fueland/or HLW involves deep geological disposal in asuitable geologic formation/environment? Becausemany formations are known to have been stable forsufficiently long time frames and are likely to remainso. For example, the bedded salt formation in which theWIPP repository resides has been stable since itsdeposition with the evaporation of an ancient oceanduring the Permian Age some 250 million years ago.The fact that the salt deposit exists is evidence that

flowing groundwater, which would have dissolved thesalt, has not been present over this geologic timeframe and will likely not be present for the 250,000years required for decay of the transuranic wastes(DOE 2003) (Figure 2).

What Is a Suitable Geologic Formation?There is no simple or single answer to the question of

what comprises an appropriate host site for a repository,as many different geological environments could provesuitable, as indicated by the diversity in candidate sitesamong international programs (Table 1) (IAEA 2003;NAS/NRC 2001). Moreover, the ultimate performance ofa repository will be driven by both the intrinsic propertiesof the geology and environment and by the features ofthe engineered barrier system, which can augment,supplement, and complement those of the natural system(Figure 3). Therefore, it is important to evaluate apotential host site in light of an appropriately matched

5 Adapted from Table I, Technical Reports Series no. 413, Scientific and Technical Basis for the Geological Disposal of Radioactive Wastes,International Atomic Energy Agency, Vienna, 2003.

Figure 2. The radiotoxicity of used nuclear fuel decreases with time due to radioac-tive decay.

Table 1. Candidate geology, hydrology, and host country for international high-level radioactive waste repositoryprograms5


repository design and components by focusing on sitecharacteristics, engineering design, and wasteformproperties; maintaining “defense in depth”; and keeping aprudent eye on the overall performance of the totalsystem versus individual system components.

Seeking a Suitable or Adequate SiteThe appropriate question to ask about a candidate

location is whether it is suitable or adequate, not whetherit is the best location. Requiring a site to be “the best”implies a level of knowledge that is unattainable withoutcharacterizing a large number of locations to a degreethat is not feasible,affordable, or wise interms of resourceutilization (NAS/NRC2001; OTA 1985).

Also, as pointed outin 1990 by the NationalAcademy of Sciences(NAS) Board onRadioactive Manage-ment, “Surprises areinevitable in the courseof investigating anyproposed site, andthings are bound to gowrong on a minor scalein the development of a

repository” (NAS/NRC 1990).Thus the pursuit of a perfectsite inevitably fails as detailedinvestigations can be expectedto reveal some nonideal featuresor characteristics. The purposeof a repository is to provideadequate protection of humanhealth and the environment bymaintaining releases belowsome defined level, which isgreater than zero. Accordingly,the repository concept neces-sarily allows for some releasesto the environment.

All Nuclear Fuel-CycleOptions Will Require

Some Form ofPermanent Disposal

Another common argumentis that fuel-cycle alternativesand advanced reactor technol-

ogy can obviate the need for a permanent geologic reposi-tory. Quite simply, all nuclear fuel cycles and alternativeswill require geologic disposal (or other form of permanentdisposal) for some form of used fuel or high-level waste atsome point in the future. Many recent arguments forpursuing advanced fuel cycles, recycling, and eventualclosure of the fuel cycle have been heavily predicated onsignificant reduction of waste inventories and radiotoxicity.However, dynamic modeling of fuel-cycle strategiesgenerally shows that waste-management benefits aremodest and offer only a secondary, not primary, justifica-tion for the pursuit of more advanced fuel cycles. For

example, Electric PowerResearch Institute(EPRI) modeling of afuel cycle optimized fordestruction of actinidesthrough the use of fastreactors as burners (asopposed to breeders)indicates that whilemodest gains areachievable in the first100 years of operation,truly substantial reduc-tions in actinide invento-ries can require timeframes on the order of100s to 1,000s ofyears (Figure 4). This

Figure 3. Long-term repository systems will rely on natural and engineered barriers to isolate,contain, and delay the release of radionuclides from used nuclear fuel and high-level waste.Repository system designs are necessarily site-specific, as engineered features need to be tai-lored to fit the geology, hydrology, seismicity, and other features of the candidate site.

(Adapted from DOE/OCRWM graphic)

Figure 4. Dynamic modeling of the entire fuel cycle by EPRI indicates thatsubstantial reductions in transuranic (TRU) nuclides require long time framesthat can exceed centuries or millennia.


challenge is due in part to the fact that new inventoriesof actinides continue to be generated even as actinidesare destroyed and large inventories of actinides aremaintained in operating reactors (EPRI 2008).

If Yucca Mountain Is Off the Table,What Is Plan B?

While permanent geologic disposal represents a funda-mental component of the nuclear fuel cycle, it is just oneelement of used fuel and HLW management and is nottechnically required for the other elements of the back endto function (Table 2). Accordingly, the termination of thecurrent repository program does not mean that utilities aresuddenly without options. The back end of the fuel cycle isan integrated system consisting of on-site storage, potentialcentralized storage, advanced nuclear fuel options, andpermanent disposal for final waste forms resulting fromcommercial nuclear power operation and recycling.

Used Fuel Can Be Safely Keptin Dry Storage for a Long Time

The challenge associated with managing usednuclear fuel is driven primarily by the large quantityof radioactivity contained in a relatively small volume,heat generation from decay of short-lived radionu-clides, and the long-lived nature of the actinides and ahandful of other nuclides. It is also important torecognize that some of these challenges are inextrica-bly linked to important advantages and benefits ofnuclear energy, particularly with respect to wastevolumes and emissions.

Used fuel represents an extremely small volume/quantity relative to the energy produced and incomparison to other comparable generation technolo-gies. For example, a model 1,000 MWe pressurizedwater reactor operating at an 80 percent availabilityfactor requires on the order of 25 metric tons of

6Information in Table 2 adapted from NAS/NRC, 2001.

Table 2. Disposition options for high-level radioactive waste6


7Data from Table 1.1, OECD/NEA, 2007. Management of Recyclable Fissile and Fertile Materials. NEA No. 6107.

fresh uranium oxide fuel annually, whereas a compa-rable coal-fired power plant consumes three millionmetric tons of coal annually (or roughly 36,500railcars) (OECD/NEA 2007). Essentially allbyproducts of nuclear-generated electricity arecontained in the relatively small volume of the originalfuel. Figure 5 illustrates the high energy density andsmall quantities of byproducts for uranium oxide fuelversus fossil sources. Nuclear energy also has thebenefit of internalizing many of the costs and impactsof energy production in terms of pollution and waste;for example, consumers of nuclear-generated electric-ity pay for the waste management of the fuel throughthe Nuclear Waste Fund fees, whereas the costs ofpollution from other comparable baseload sources ofelectricity mostly remain external to electricitypricing. In principle, there is no technical limit to drystorage during the period of institutional controls.

Currently deployed systems can belicensed under the present USNRCregulations up to 60 years, and workis underway to understand longer-term aging issues. Numerous state-ments from USNRC staff and thecommission suggest that U.S. regula-tors have confidence in dry storagesystem lifetimes of 100 years or more(Klein 2009). Metal and concrete structures builtby humans are known to persist formillennia, as shown in Table 3. TheEiffel Tower, an iconic Parisianlandmark, was constructed of ironusing 19th century erection methodsand technology. Yet the 120-year-old,324-meter, 10,000-metric-tonattraction remains standing and inuse with the help of a fresh coat ofpaint every seven years (Visit Guide:

The Eiffel Tower Web site). It is worth noting thatconcrete and metal alloys employed in dry storagesystems are designed with degradation/corrosionresistance in mind and that the field of materialscience has greatly enhanced the durability andcorrosion resistance of concrete and metal alloys.With routine inspection and maintenance, robustengineered systems such as dry cask storage systemscan be expected to remain operable over periodsextending well beyond a century (EPRI 2003; Milleret al. 2006).

If necessary, any limitations on canister/casksystem lifetimes and performance can be overcomethrough periodic repackaging. While feasible, repeatedhandling of the same fuel is not desirable because itwill incur additional occupation exposures and willpresent substantial logistical challenges in situationswhere wet storage facilities are no longer available forconducting fuel transfers and inspections.

Figure 5. Quantities associated with generation of 7 TWh of electricity (1,000 MWepower plants operating at an 80 percent load factor)7

Table 3. Examples of archaeological structures and artifacts that indicate persistence of structural materials overmillenia


Figure 6. Representative composition of uranium oxide fuel (nominally 3 percent235U initial enrichment) following irradiation in a light water reactor for electric-ity generation

Used Fuel: Waste or Resource?After low-enriched uranium oxide fuel is irradiated in a

light water reactor (LWR) to a point where increasingneutron poison concentrations and decreasing fuelreactivity become limiting, the used or “spent” fuel isdischarged and replaced by fresh fuel. However, asillustrated in Figure 6, very little of the total uraniumresource is consumed in the reactor, and otheractinides are produced that have potential value forrecovery and use in nuclear fuels. The remaining 235Upersists at or near natural enrichment levels, 238Ucontinues to represent the bulk of fuel material (at~93 percent), and fissile plutonium isotopes (239Puand 241Pu) comprise almost 1 percent of the used fuelinventory by mass. The 4-5 percent fission productfraction represents the truly unusable portion—requiring disposal regardless of the fuel-cycle optionselected. The remaining 95-96 percent of material inthe used fuel could potentially be recovered. In short,used fuel can be considered a waste if the existingtechnology continues to dominate the fuel cycle, i.e.,LWRs that can only make secondary and minimal useof the 238U present.

However, used fuel could offer an untapped andvery large energy resource if advanced commercial

reactor technologies, such as fast reac-tors, are deployed on a sufficient scale tomake full use of 238U as a fertile source offissile 239Pu. Ultimately, the necessary fuel-cycledecisions must be made at the nationallevel. Major fuel-cycle facilities are large,complex, high-risk, and expensive projectsnot well suited for private investment.Fuel-cycle goals, attributes, and waste-disposal requirements ultimately touch onissues and policies that must be addressedat the national level, such as nonprolifera-tion, energy, disposal, economic develop-ment, and national security. With the apparent end to the YuccaMountain program, the United States hassurrendered an international leadership rolein the nuclear waste management arena, asother countries with nuclear technology

continue down the path blazed in large part by theUnited States (NWTRB 2009).

In any case, some form of permanent disposal ofHLW will be required for all fuel-cycle options. Thedecision not to proceed with Yucca Mountain, therefore,cannot erase the fact that the United States will need todevelop a permanent disposal route for its nuclear fuelcycle, and this route will likely be a deep geologicrepository.

ConclusionFrom a technical perspective, the question isn’t, What

can we do with the used nuclear fuel from commercialnuclear power generation? Technical answers to thisquestion exist. Rather, the relevant question remains,What will we do with used nuclear fuel?

The key to answering this question lies not only indefining what is technically possible, but also in deter-mining which option (or options) can receive sufficientpublic and political support to maintain viability over themultidecade time frame that any credible solution willtake to implement. In a democratic society such as ours,this is primarily a question for elected and duly-ap-pointed decision makers, although hopefully, the finalanswer will be well informed by science and engineering.

Editors’ Note: We would like to express our utmost appreciation to the authors of this series for theirpatience, hard work, and dedication to high standards of excellence in producing their articles. We sin-cerely hope that we have achieved our mutual goal of conveying the challenges and opportunities arisingin nuclear power health physics to our friends and colleagues across the Health Physics Society.


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Andrew Sowder is a projectmanager at the Electric PowerResearch Institute (EPRI) inCharlotte, North Carolina, wherehe conducts and coordinatesresearch related to managementof used nuclear fuel and high-level radioactive waste andanalysis of advanced nuclear fuelcycles.

Prior to joining EPRI, Andrewserved as a physical scientist andforeign affairs officer at the U.S.Department of State, addressinginternational nuclear safety andradiological security issues,including policy and technicalanalysis supporting U.S. oversight of Chernobyl-related programs.

He also served as an advisor to the United NationsScientific Committee on the Effects of AtomicRadiation (UNSCEAR) from 2004 to 2007 and wascertified by the American Board of Health Physics in2006.

He received a BS in optics from the University ofRochester in 1990 and a PhD in environmentalengineering from Clemson University in 1998, where

his training and research focusedon health physics, radiochemistry,and uranium geochemistry. He conducted postdoctoralenvironmental research at theSavannah River Ecology Labora-tory located on the Department ofEnergy’s Savannah River Site,where he also collaborated exten-sively with environmental microbi-ology researchers at the MedicalUniversity of South Carolina. He entered the realm of sciencepolicy in 2000 as an AmericanAssociation for the Advancementof Science environmental fellow atthe U.S. Environmental Protection

Agency’s (EPA) Office of Radiation and Indoor Air inWashington, DC. While at the EPA, Andrew had thehonor of participating in educational outreach pro-grams on the Navajo Nation for communities im-pacted by abandoned uranium mines.

Andrew lives in Charlotte, North Carolina, in a cozyhouse under a really big tree with his wife, Dean, twodaughters and a son, three dogs, and a cat. When hehas time, he likes to read, go on walks with kids and/or dogs, and mess about in the yard.

the resurgence of nuclear power - the health physics society

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