GAO

United States General Accounting Office

Report to the Honorable

Pete Domenici, U.S. Senate

June 2000 RADIATION

STANDARDS

Scientific Basis

Inconclusive, and EPA

and NRC

Disagreement

Continues

GAO/RCED-00-152

Page 1 GAO/RCED-00-152 Radiation Standards

Contents

Letter 3

Appendixes Appendix I: Scope and Methodology 32

Appendix II: Major U.S. Radiation Standards 34

Appendix III: Examples of Different Models of Low-Level

Radiation Effects 35

Appendix IV: Overview of Epidemiological Research on

Low-Level Radiation Effects 36

Appendix V: Costs of Different Radiation Standards 40

Appendix VI: Comments From the Environmental

Protection Agency 46

Appendix VII: Comments From the Nuclear Regulatory

Commission 56

Appendix VIII:Comments From the Department of Energy 58

Tables Table 1: Estimated Costs to Achieve Different Soil Cleanup

Levels at Selected DOE Sites and Generic

NRC-Licensed Sites 27

Table 2: Potential Costs to Achieve Different Soil Cleanup

Levels—DOE’s, NRC’s, and EPA’s Analyses 41

Figures Figure 1: The Linear, No-Threshold Model of Low-Level

Radiation Effects 11

Figure 2: Four Models of Low-Level Radiation Effects 35

Figure 3: Cleanup Costs as a Function of Cleanup

Levels—Hazardous Waste Facility, Brookhaven

National Laboratory, 1998 43

Abbreviations

DOE Department of Energy

EPA Environmental Protection Agency

GAO General Accounting Office

NRC Nuclear Regulatory Commission
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United States General Accounting Office

Washington, D.C. 20548

Resources, Community, and

Economic Development Division

B-284378 Letr

June 30, 2000

The Honorable Pete Domenici

United States Senate

Dear Senator Domenici:

As the cold war came to a close, the United States shifted its focus from

producing nuclear weapons to cleaning up its nuclear weapons production

facilities. The Department of Energy (DOE), which manages the U.S.

nuclear weapons program, is now cleaning up over a dozen major weapons

production sites around the country. In addition, the nation’s nuclear power

industry is starting to decommission over 100 commercial nuclear power

plants located in 31 states, a task that will continue during the coming

decades. Furthermore, DOE is determining the feasibility of constructing

an underground repository to provide for permanently disposing of much

of the nation’s highly radioactive waste at Yucca Mountain, Nevada. Until a

repository is operational, federal facilities and nuclear power plants across

the country will continue to store their highly radioactive waste on-site.

What standards should be used to protect the public from the risks of

exposure to low-level radiation remaining at these sites after the nuclear

materials and wastes have been removed—or, in the case of Yucca

Mountain, to protect the public from exposure to the buried waste—is a

question for which two federal agencies share primary responsibility. The

Environmental Protection Agency (EPA) issues generally applicable public

radiation protection standards and administers the Comprehensive

Environmental Response, Compensation, and Liability Act of 1980

(Superfund), which governs cleanups of federal and nonfederal facilities.

The Nuclear Regulatory Commission (NRC) issues implementing radiation

protection standards as part of its mandate to regulate civilian sources of

nuclear radiation, and it oversees the decommissioning of commercial

nuclear facilities. The states may also be involved in radiation protection

efforts under agreements with NRC for nuclear facilities within their

jurisdictions. Finally, the National Academy of Sciences has a

congressionally mandated role in recommending radiation protection

standards for the Yucca Mountain repository.
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Historically, EPA and NRC have sometimes differed over how restrictive

U.S. radiation protection standards should be, as we reported in 1994.1

These differences have implications for the pace and cost of federal facility

cleanups and commercial decommissioning efforts, as well as for the

design and potential development of the Yucca Mountain repository.

Concerned about these issues, you asked us to examine the scientific basis

for the agencies’ radiation protection standards and the costs of

implementing them. As agreed with your office, this report examines (1)

whether the current U.S. radiation protection standards have a wellverified scientific basis, (2) whether federal agencies have come closer to

agreeing on standards since we reported on this issue in 1994, and (3) how

implementing these standards may affect the costs of nuclear waste

cleanup and disposal activities. During our review, we examined many

scientific studies and obtained the views of recognized scientists on the

scientific basis of radiation standards. We focused mainly on differences in

standards for Yucca Mountain and nuclear cleanup and decommissioning

sites because they are prominent current examples of the debate about

standards. In addition, the report includes a review, performed by a

recognized expert in environmental radiation, of scientific research

correlating naturally occurring (background) radiation levels in the United

States and around the world with local cancer rates. This review was

designed to determine whether the research results might have

implications for setting radiation protection standards. (See app. I for a

detailed discussion of our scope and methodology.)

Results in Brief U.S. regulatory standards to protect the public from the potential health

risks of nuclear radiation lack a conclusively verified scientific basis,

according to a consensus of recognized scientists. In the absence of more

conclusive data, scientists have assumed that even the smallest radiation

exposure carries a risk. This assumption (called the “linear, no-threshold

hypothesis” or model) extrapolates better-verified high-level radiation

effects to lower, less well-verified levels and is the preferred theoretical

basis for the current U.S. radiation standards. However, this assumption is

controversial among many scientists. Some say that the model is overly

conservative and that below certain exposure levels, there is no risk of

cancer from radiation. Others say that the model may underestimate the

risk. The research evidence is especially lacking at regulated public

1

Nuclear Health and Safety: Consensus on Acceptable Radiation Risk to the Public Is

Lacking (GAO/RCED-94-190, Sept. 19, 1994).
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exposure levels—levels of 100 millirem a year and below from humangenerated sources. Interest among scientists in obtaining a more

conclusive understanding of the effects of low-level radiation has been

evident in recent federally funded initiatives, including a reassessment by

the National Academy of Sciences of the latest research evidence on the

risks of low-level radiation, begun in the summer of 1998 and planned to

conclude in 2001. Also, a 10-year DOE research program, begun in fiscal

year 1999, has been specifically addressing the effects of low-level

radiation within human cells, in part to help verify or disprove the linear

model.

Lacking conclusive evidence of low-level radiation effects, U.S. regulators

have in recent years set sometimes differing exposure limits. In particular,

EPA and NRC have disagreed on exposure limits. Although we

recommended as far back as 1994 that the two agencies take the lead in

pursuing an interagency consensus on acceptable radiation risks to the

public, they continue to disagree on two major regulatory applications: (1)

the proposed disposal of high-level nuclear waste in a repository at Yucca

Mountain and (2) the cleanup and decommissioning of nuclear facilities.

Centrally at issue between the two agencies is groundwater protection. On

the one hand, EPA applies community drinking water limits for radioactive

substances to groundwater at nuclear sites, as a matter of water resource

protection policy. Some of these limits are equivalent to fractions of a

millirem a year. On the other hand, NRC includes groundwater and other

potential contamination sources under a less restrictive limit of 25 millirem

a year for all means of exposure,2 an approach that conforms to

internationally recommended radiation protection guidance. As applied in

proposed standards for nuclear waste disposal at Yucca Mountain, EPA’s

groundwater approach has been criticized as technically unsupported by

the National Academy of Sciences, which the Congress mandated to

recommend standards for the repository. However, the Academy

recognizes that EPA has the authority to establish a separate groundwater

limit for Yucca Mountain, and EPA believes its groundwater protection

approach for the repository to be technically justified. As applied to

nuclear cleanup and decommissioning sites where both EPA and NRC may

have jurisdiction, the two agencies’ different regulatory approaches have

sometimes raised questions of inefficient, conflicting, dual regulation.

There has been little progress in finalizing a memorandum of

2

These means of exposure, called “pathways” by specialists, include exposure through soil,

water, and air.
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understanding, encouraged by the House Appropriations Committee in

August 1999, to resolve EPA’s and NRC’s conflict about cleanup standards.

Given their historical differences, EPA and NRC may not easily agree on

groundwater protection standards for Yucca Mountain or on their

respective regulatory roles relating to nuclear cleanup and

decommissioning sites. This report contains a matter for congressional

consideration suggesting that, in such a situation, the Congress may wish to

help resolve the agencies’ disagreement.

The costs of implementing different radiation standards vary, depending on

the standards’ restrictiveness. Generally, the costs increase as the

standards become more restrictive. Comprehensive estimates of overall

costs to comply with current and prospective standards were unavailable,

but these costs could be immense, considering that federal agencies expect

to fund hundreds of billions of dollars in nuclear waste disposal and

cleanup projects over many years in the future. According to DOE’s and

NRC’s analyses of cleanup options for individual sites, costs per site can be

many millions of dollars higher to comply with more restrictive standards

than less restrictive standards, as might be expected. For example, a 1995

DOE analysis of cleanup options for plutonium-contaminated test ranges at

the Nevada Test Site estimated $35 million in costs to achieve a 100-

millirem-a-year-level, over three times as much to achieve a 25-millirem-ayear level, and over six times as much to achieve a 15-millirem-a-year level.

Finally, the analysis showed costs that were over 28 times higher to achieve

a 5-millirem-a-year level, illustrating that compliance costs accelerate

rapidly to achieve the most restrictive protection levels.

We presented a draft of this report to NRC, DOE, and EPA for comment.

NRC found the report to be fundamentally sound, and DOE found it to be

factual and balanced. EPA disagreed with the report’s conclusions,

particularly our conclusion that there has been little progress on the

finalization of a memorandum of understanding to resolve EPA’s and NRC’s

conflict about cleanup standards. However, although the two agencies are

developing such a memorandum, they have had long-standing differences,

and we question whether their latest efforts will resolve these differences

without congressional intervention. All three agencies provided technical

comments on the report. In response to the comments received, we made

some changes to the report’s presentation.
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Background Nuclear radiation can be generally categorized as either low-level or highlevel radiation. The low-level range includes exposures up to about 10,000

total millirem, 3 although the term commonly is used to refer to exposures

of a few hundred millirem or less.4 The lower portion of the low-level range

includes natural background radiation levels, and the lowest portion of this

range includes public exposure levels regulated under various U.S.

radiation standards, as shown in appendix II.5 Natural background

radiation levels vary around the world, from below 100 millirem of

exposure a year in some places to several hundred millirem a year in

others, with even higher levels recorded in “hot spots.” In the United States,

average natural background radiation exposure is about 300 millirem a

year. In addition, medical practices, such as X-rays and nuclear medicine,

and industrial nuclear operations contribute average public exposures of

about 50 millirem a year and 0.1 millirem a year, respectively. Radiation

from within one’s own body, largely from naturally present radioactive

potassium, contributes almost 40 millirem a year, on average. As shown in

appendix II, regulatory public exposure limits vary from a few millirem a

year up to 100 millirem a year. At these levels, radiation is only one of many

environmental and biological events (such as heat) that may alter (mutate)

cell structure, and low-level radiation is commonly considered to be a

relatively weak source of cancer risk.6 To counter these cellular-level

mutations, the human body has active repair processes, although these

processes are not entirely error-free, and their relevance to human cancer

risk remains unclear. Should a radiation-caused cancer develop in one or

more cells, the process may take years, and the source of the cancer will be

verifiable only in exceptional cases, given the current limited

3

A millirem is a commonly used unit of measurement of the biological effect of radiation.

The radiation from a routine chest X-ray is equivalent to about 6 millirem.

4

Above about 30,000 total millirem, radiation exposure is a well-known cause of cancer.

Instantaneous (or short-duration) exposures of about 200,000 total millirem can cause blood

cell changes, infections, and temporary sterility. Short-duration exposures above about

400,000 total millirem can cause death within days or a few weeks and are associated with

catastrophic nuclear accidents or atomic bomb blasts.

5

U.S. worker protection standards limit annual exposures to 5,000 millirem. See app. II.

6

About 187,000 spontaneous cell-altering events occur daily in each human cell. Low-level

radiation exposures increase the number of such events by a small fraction—about 1

percent. There is evidence that the type of damage done by such radiation has a higher

probability of resulting in DNA misrepair than the type of damage done by other normally

occurring cell-altering events.
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understanding of how cancer develops. Although nearly one in four

persons in the United States dies of cancer from all causes, low-level

radiation presumably accounts for a very small fraction of these cancers, if

any. However, the fraction cannot be quantified.

Federal agencies, and in some instances states, administer U.S. radiation

standards. EPA and NRC administer the majority of the federal standards.

EPA issues environmental radiation protection standards as mandated

under Presidential Reorganization Plan No. 3 of 1970. NRC issues standards

as part of its mandate to regulate civilian sources of nuclear radiation,

under the Atomic Energy Act. (Under the same act, DOE has issued public

and worker exposure limits applicable on-site at the agency’s nuclear

installations.) Both EPA and NRC have regulatory roles related to nuclear

waste disposal and nuclear site cleanup and decommissioning. For

example, under the Energy Policy Act of 1992, both have roles at the

proposed Yucca Mountain repository in southern Nevada. The proposed

function of the repository is to receive and dispose of high-level waste from

DOE sites and commercial power plants around the country. EPA has the

role of issuing standards to protect the public from releases of radioactive

materials from the facility, and NRC has the role of issuing technical

requirements and criteria and licensing the facility. Under the act, exposure

limits in NRC’s final technical requirements and criteria are to be consistent

with the limits in EPA’s final public protection standards. DOE’s role at

Yucca Mountain will be as the developer and prospective operator of the

repository, and the Department is pursuing the goal of deciding in 2001

whether to recommend the site to the President as suitable for nuclear

waste disposal. Also involved in Yucca Mountain oversight are expert

advisory bodies, including the Nuclear Waste Technical Review Board and

the National Academy of Sciences, which was mandated under the Energy

Policy Act of 1992 to recommend standards for the repository. In regard to

nuclear cleanup and decommissioning activities, both EPA and NRC have

mandated roles: EPA administers Superfund, the legislation that governs

cleanups of federal and nonfederal facilities, and NRC regulates the
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decommissioning of over 100 active commercial nuclear power plants, as

well as other commercial nuclear facilities, under the Atomic Energy Act.7,8

Our September 1994 report on radiation protection issues found that U.S.

radiation standards reflected a lack of federal agency consensus on

acceptable radiation risk to the public, as well as a lack of interagency

coordination on standards. Among the reasons we found for the lack of

consensus were differences in agencies’ historical missions and legislative

mandates, as well as differences in agencies’ regulatory strategies,

particularly in those of EPA and NRC. For example, EPA has historically in

many cases implemented a risk-based radiation protection approach, under

which the agency addresses individual contamination sources, coregulates

chemicals and radioactive substances, and protects both human health and

environmental resources.9 In accordance with its tradition of regulating

chemicals, EPA has generally set a risk of 1 in a million that an individual

will develop cancer in a lifetime as a goal for remediation and has

considered a risk of greater than 1 in 10,000 to be potentially excessive.

EPA’s approach has been described as “bottom up,” setting a relatively

restrictive risk goal to be pursued through the best available technology—

but allowing less restrictive limits in site-specific situations. In contrast,

NRC favors a dose-based, radiation-specific protection approach that

focuses on human health protection.10 NRC’s protection strategy has been

7

Superfund regulations call for, among other steps, the development of cleanup alternatives

through a remedial investigation, the finalization of applicable cleanup requirements, and a

formal record of decision on an agreed cleanup level, after which cleanup is conducted.

Decommissioning involves the removal of all radioactive components and materials from

the facility and the cleanup of radionuclides to NRC’s standards (10 C.F.R. 20).

8

The coordination of federal radiation protection issues is the responsibility of the federal

Interagency Steering Committee on Radiation Standards, and coordination among states is

the responsibility of the Conference of Radiation Control Program Directors. In addition,

authoritative national and international technical organizations make recommendations on

radiation protection issues, including the congressionally chartered U.S. National Council

on Radiation Protection and Measurements, the International Commission on Radiological

Protection, and the United Nations Scientific Committee on the Effects of Atomic Radiation.

9

EPA’s protection approach draws, in part, on experience with regulating thousands of

different chemicals, many of which pose risks that are generally thought to be even less well

understood than radiation risks. These chemicals may or may not exist naturally in the

environment.

10NRC’s approach (with which DOE generally concurs) draws on experience in estimating

radiation-specific risks, within an internationally recommended radiation dose limitation

and risk assessment framework. The framework takes into account that radiation exists

naturally in the worldwide environment.
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described as a “top down” approach. Compared with EPA, NRC sets a

relatively less restrictive dose limit but reduces doses (and risks) well

below the limit in site-specific situations where the reductions are

“reasonably achievable.”11

U.S. Public Radiation

Protection Standards

Lack a Conclusive

Scientific Basis

The standards administered by EPA and NRC to protect the public from

low-level radiation exposure do not have a conclusive scientific basis,

despite decades of research. These standards are based on a hypothetical

model of low-level radiation effects. The model, derived from studies of

large populations (in the tens of thousands) exposed to radiation,

extrapolates better-verified high-level radiation effects to lower, less wellverified levels. The standards protect at annual millirem levels

considerably lower than the better-verified levels. According to a

consensus of scientists, there is a lack of conclusive evidence of low-level

radiation effects below total exposures of about 5,000 to 10,000 millirem.

The model under which these effects are assumed, lacking conclusive

evidence, is called the “linear, no-threshold” hypothesis or model.

According to this model, even the smallest radiation exposure carries a

quantifiable cancer risk. The model, which has been endorsed by national

and international radiation protection organizations and used for many

years as a preferred model in regulating low-level radiation, is a

fundamental basis for U.S. radiation standards. There is interest among

scientists in obtaining more conclusive evidence of radiation effects, and a

DOE research program that is examining cellular low-level radiation effects

may eventually help to develop a better understanding of the cellular

processes of radiation cancer causation.

Low-Level Radiation Effects

Are Assumed for Regulatory

Purposes

Conclusive evidence of radiation effects is lacking below a total of about

5,000 to 10,000 millirem, according to the scientific literature we examined

and a consensus of scientists whose views we obtained. At these

11NRC’s 25-millirem-a-year dose limit is equivalent to 1 chance in about 1,000 of a fatal

cancer over a 70-year lifetime, using a commonly accepted dose-risk conversion factor and

assuming the linear model of radiation effects holds.
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levels, authoritative bodies have estimated radiation risks through complex

modeling of the available data,12 and regulators have assumed that even the

smallest radiation exposure carries a risk. This assumption is commonly

referred to as the linear, no-threshold hypothesis or model. Extrapolated

mainly from high-dose effects reported for Hiroshima and Nagasaki

survivors, the linear model assumes that radiation health effects are

proportional to exposure. As figure 1 shows, the model uses a straight line

to extrapolate risks all the way down to zero. From zero upward, the

model assumes that as exposure doubles, risk doubles, and that no entirely

risk-free exposure level or threshold exists.

Figure 1: The Linear, No-Threshold Model of Low-Level Radiation Effects

Radiation protection organizations such as the National Council on

Radiation Protection and Measurements and the International Commission

on Radiological Protection have historically endorsed the model, and U.S.

regulators have used it as a preferred, plausible model, but it is

controversial. On the one hand, the model is widely considered to be a

useful, relatively mathematically simple working hypothesis that may be

12For example, a 1990 study by a National Academy of Sciences committee, called BEIR V,

estimated that, at the 90-percent statistical confidence interval, out of 100,000 adults

exposed to 100 millirem a year of radiation over a lifetime, anywhere from 410 to 980 men

and 500 to 930 women might die of cancer caused by the exposure. This confidence interval

assumes the validity of the linear model and reflects the uncertainty of inputs to the model.
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conservative—that is, it may not underestimate risks. Regulators make use

of the model in doing risk assessments, regulatory impact analyses, costbenefit analyses, and other studies to support their decision-making. In

using the model, they are able to estimate risk reductions and hypothetical

lives saved from regulating at a given exposure level. On the other hand,

many scientists question the validity of the model. The consensus view we

encountered is that the research data on low-level radiation effects are

inadequate either to establish a safety threshold or to exclude the

possibility of no effects. Scientists we contacted and scientific literature we

examined generally did not indicate that any one model clearly best fit the

overall data. Instead, there was evidence that any of several models may

“fit.” (See app. III.) Some researchers also said low-level radiation effects

are likely too complicated and variable to be expressed in a single model.

There is evidence that the relationship may vary in individuals, and with the

type of radiation, type of cancer, body organs exposed, sex, and/or age at

exposure. We also found considerable agreement among regulators and

scientists that the linear model may be a conservative “fit” to the data,

unlikely to underestimate risks. However, some said the data support the

existence of a safety threshold below which there are no risks, and others

said low levels of radiation can be beneficial to health. This is a highly

controversial theory, called hormesis, which is in part based on the

documented ability of the body to repair cell damage—referred to as

adaptive response. However, other scientists pointed to studies indicating

the linear model may actually understate radiation risks, especially to

fetuses and children.13

Authoritative radiation protection organizations and committees have

given the linear model a qualified endorsement. For example, in 1990, a

committee of the National Academy of Sciences, the Biological Effects of

Ionizing Radiation Committee (BEIR V), reported that the linear model was

not inconsistent with the available research data. According to the

committee’s report, at low radiation exposures, risks either less or greater

than linearity—and the existence of a threshold in the low-level dose

range—cannot be excluded, and “the possibility that there may be no risks

from exposures comparable to external natural background radiation

cannot be ruled out. At such low doses, it must be acknowledged that the

lower limit of the range of uncertainty in the risk estimates extends to

zero.” In addition, a 1994 report of the United Nations Scientific Committee

13There is evidence of mental retardation linked to fetal exposure to low-level radiation. Age

at time of exposure appears to be an important determinant of cancer risk from radiation.
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on the Effects of Atomic Radiation (UNSCEAR) stated that “there are

theoretical reasons based solely on the nature of DNA damage and repair to

expect that cancer can occur at the lowest doses without a threshold in the

response, although this effect would perhaps not be statistically

demonstrable.”14 Despite the linear model’s unproven and controversial

status among scientists, some scientists said the model is so well accepted

that it could only be superseded on the basis of overwhelming contrary

evidence.

Research Efforts to Verify

Low-Level Radiation Effects

Are Ongoing

Two types of important research into low-level radiation effects have been

conducted. One type of study painstakingly follows the long-term health of

individuals in large populations exposed to radiation, seeking statistically

significant patterns of elevated cancer risks from the radiation exposures.

These are called epidemiological studies. Another type of study subjects

animals or tissue or cell cultures to radiation, seeking biological evidence

of radiation effects. These are called radiobiological studies.

Epidemiological studies may never conclusively prove or disprove the

linear model, according to some scientists. Epidemiological studies have

been a key basis for the linear model, including the research evidence

accumulated on over 85,000 Japanese survivors of the Hiroshima and

Nagasaki bomb blasts. The study, conducted by the international Radiation

Effects Research Foundation, has well established the effects of radiation

at high exposure levels, and scientists have extrapolated this relationship

to the low-level radiation range as well—with considerable inherent

uncertainty.15 However, some scientists have questioned the project’s

results, asserting among other concerns that the basic estimates of the

Hiroshima and Nagasaki doses (and their neutron component, for

example) still need to be reevaluated, even after decades of effort devoted

to determining these doses.

As noted, epidemiological studies require large study populations for the

research results to be statistically powerful. Epidemiologists consider two

14The British National Radiation Protection Board similarly maintains, in consideration of

relevant cellular and molecular data, that the weight of evidence falls decisively in favor of

the thesis that for a majority of common human tumors, low-dose and low-dose-rate cancer

risk rises as a simple function of dose with no threshold.

15According to one expert, extrapolating effects from high exposures to low exposures

equivalent to natural background radiation levels is more guesswork than science.
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types of epidemiological studies—analytic or ecologic. Analytic studies

either compare individuals who have been exposed to radiation to

individuals who have not been exposed and determine if there are

subsequent differences in their health status (cohort studies) or compare

individuals who have a disease to those who do not to determine if there

were differences in the past exposures of the two groups (case control

studies). Ecologic studies rely on regional data on disease and radiation

levels, instead of individual data, and are considered to be less reliable than

analytic studies. Analytic and ecologic studies have attempted to correlate

regional natural background radiation levels with regional cancer rates at

locations in the United States, Europe, Asia, Brazil, Iran, and other places.

A premise related to such studies is that, if the linear model holds, cancer

rates should be higher at locations where natural background radiation

levels are significantly higher. With the help of an expert consultant, we

examined 82 studies, which generally found little or no evidence of

elevated cancer risks from high natural background radiation levels. A

large number of studies reported a lack of evidence of cancer risks, some

others reported evidence of slightly elevated risks, and some others

reported evidence of slightly reduced risks. Overall, the studies’ results are

inconclusive, but they suggest that at exposure levels of a few hundred

millirem a year and below, the cancer risks from radiation may be either

very small or nonexistent. (See app. IV.)

Radiobiological studies, particularly molecular studies, may eventually

develop more conclusive scientific evidence of low-level radiation effects

than epidemiological studies, according to scientists. Past radiobiological

research has helped to establish, among other evidence, the genetic effects

of radiation and its effects on individual body organs. Recently, there has

been interest in research into the cellular processes through which

radiation causes cancer, in part in relation to progress in human genome

research in the 1990s.16 Researchers have been obtaining a better

understanding of specific phenomena such as DNA damage and repair,

chromosomal instability, so-called “bystander” effects on neighboring cells,

and cellular adaptation to exposures. Researchers are looking into such

cellular processes for biological signs (or “biomarkers”) of radiation cancer

causation. Several stages are apparent in the development of radiationcaused cancer: DNA damage, misrepair, cancer initiation, cell proliferation,

and tumor promotion (with subsequent malignant transformation). To date,

the first stage in the process is better understood than the long-term second

16Such research focuses on cells’ nuclei, where DNA is located.
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stage. Since fiscal year 1999, DOE has funded a research program targeting

the biological effects of low-level radiation at the cellular level, with total

funding of almost $220 million projected over 10 years. The program is

considered unique in that it is designed specifically to better validate the

effects of very low levels of radiation in areas such as cells’ response to

radiation damage, thresholds for low-dose radiation effects, and features

distinguishing radiation-caused cell damage from damage from causes

internal to the cell. Many scientists and regulators we interviewed said this

type of research could eventually help to determine more conclusively the

effects of low-level radiation and their potential link to cancer causation.

In October 1998, the National Academy of Sciences contracted to reassess

the linear model and risk estimates for low-level radiation, at the request of

U.S. regulators, including EPA, NRC, and DOE. The regulators, acting

through the Interagency Steering Committee on Radiation Standards,

concluded that enough research progress had been made in the 1990s to

warrant the study. The Academy last did such an assessment in 1990, called

BEIR V. The latest assessment, called BEIR VII, is to be completed by

2001.17 High expectations have been set for the BEIR VII committee,

reflecting the scientific controversy surrounding the linear model and lowlevel radiation effects. For example, in requesting the effort, EPA, DOE,

and NRC asked the committee to focus on areas the agencies do not believe

were emphasized in the previous BEIR V effort. EPA asked the committee

to provide a clear indication of the weight of evidence for risks at low doses

and dose rates and to carefully assess the sources of any inconsistencies in

the results from different epidemiological studies. DOE asked BEIR VII to

consider epidemiological studies on nuclear workers, and NRC asked the

committee to focus especially on evidence of radiation effects at the lowest

portion of the low-level radiation range, at levels where regulators set

radiation standards, and to consider evidence of hormesis. Also, the

committee is committed to fully assessing all pertinent research data, not

just the data that have been traditionally influential, such as the Hiroshima

and Nagasaki data. Because of its broad focus, the BEIR VII assessment

could produce instructive results, but some agency officials and scientists

said the amount of new research data available might not be sufficient to

lead the committee to either fully validate or disprove the linear model. An

EPA official said he expected the BEIR VII work to support the continued

use of the linear model for regulatory purposes.

17BEIR VI was a 1999 Academy assessment of risks from radon.
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EPA and NRC Continue

to Disagree on Major

Radiation Standards

for Public Protection

We reported in 1994 that federal agencies’ radiation standards reflected a

lack of consensus on acceptable risk to the public. Today, this situation

persists, and EPA and NRC, the principal federal radiation standard-setting

agencies, continue to disagree significantly on regulatory approaches and

standards related to groundwater protection. Two major instances of their

disagreement are proposed standards for the prospective Yucca Mountain

high-level-waste repository and standards for the cleanup and

decommissioning of federal and commercial nuclear facilities. For these

applications, EPA favors both (1) a public protection limit of 15 millirem a

year from all radiation sources through all means of exposure—called “all

pathway” protection by specialists—and (2) extra protection of

groundwater resources under sites, at limits originally set for community

drinking water systems, equivalent to 4 millirem a year. Alternatively, NRC

favors a single 25-millirem-a-year all-pathway public protection limit,

within which groundwater is a potential pathway.18 This disagreement has

complicated planning for the prospective Yucca Mountain high-level waste

repository, on which a national decision is to be made in 2001, as well as

day-to-day planning for facility decommissioning by commercial nuclear

operators licensed by NRC. In both of these cases, it remains to be seen

whether EPA and NRC can resolve their differences or whether the

Congress will need to intervene.

EPA and NRC Have

Proposed Different HighLevel-Waste Disposal

Standards

The disagreement between EPA and NRC on groundwater protection is

reflected in differences in the radiation standards set by the two agencies

but appears most notably in the debate over proposed draft standards for

the Yucca Mountain, Nevada, high-level-waste repository. Radiation

standards are an important part of the ongoing debate about the future of

the planned facility. Both EPA and NRC issued proposed radiation

protection standards for the repository in 1999, NRC in February and EPA

in August. The agencies differ on proposed all-pathway limits (15 millirem a

year versus 25 millirem a year), and especially on extra groundwater

protection. The groundwater issue at Yucca Mountain relates to differences

in the two agencies’ overall resource protection policies, as well as

technical details. EPA’s approach reflects its attempt to implement a

18EPA’s approach includes various levels of acceptable risk, from 1 chance in about 2,000 to

less than 1 chance in about a million of a fatal cancer over a 70-year lifetime. NRC’s allpathway approach involves a level of acceptable risk of 1 chance in about 1,000 of a fatal

cancer over a lifetime. These calculated risks are based on a commonly used dose-risk

conversion factor, assuming the linear model holds.
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consistent policy, across various standards, of protecting groundwater as a

national resource, in line with community drinking water standards

established in regulations under the Safe Drinking Water Act. (According to

EPA, the policy is based on preventing pollution before it occurs. If

pollution has occurred, the polluter should be responsible for the costs of

cleanup.) On the other hand, NRC believes its all-pathway approach is fully

protective of human health at Yucca Mountain and elsewhere. In the

Commission’s view, EPA’s drinking water standards were not originally

intended for an application such as Yucca Mountain, and the Commission

questions EPA’s technical basis for proposing extra groundwater

protection.19,20

NRC has been joined in its views by DOE and some others who have

commented on EPA’s proposed Yucca Mountain standards, including the

National Academy of Sciences. The Academy has questioned the technical

basis for EPA’s extra groundwater protection approach. Specifically, the

Academy, together with NRC, DOE, and other commenters, has asserted,

first, that EPA has not provided a technical rationale for its approach. By

contrast, according to these commenters, NRC has a technically based

rationale for its approach that is in accord with internationally

recommended radiation protection practices. Second, the Academy and

others have pointed out that the drinking water concentration limits to be

applied to groundwater at the repository are outdated, reflecting doses and

risks that are inconsistent. These limits consist of dozens of numerical

maximum contaminant levels for radionuclides, expressed in picocuries

per liter, which reflected consistent doses and risks when they were

19The agencies also disagreed on low-level waste disposal standards in the mid-1990s.

Current low-level waste standards consist of NRC’s 25-millirem-a-year all-pathway limits

that date from 1983. In 1994, EPA considered issuing its own standards, reflecting 15-

millirem-a-year all-pathway protection, plus extra groundwater protection to drinking water

standards. At the time, DOE estimated over $300 million in added annual costs if its disposal

sites and commercial disposal sites were required to comply with the approach EPA was

considering.

20In addition, in 1994, EPA issued transuranic waste disposal standards for the Waste

Isolation Pilot Project in southeastern New Mexico (40 C.F.R. 191) that include 15-millirema-year all-pathway limits, plus extra groundwater protection to drinking water standards.

NRC expressed concerns about the groundwater protection standards but concurred with

them because on-site groundwater was not an issue in EPA’s project certification process—

the aquifer was brine. Transuranic waste is tools, rags, laboratory equipment, and other

items contaminated with radioactive elements, mostly plutonium.
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established in regulations implementing the Safe Drinking Water Act of

1976.21 These limits are outdated under the latest risk estimation methods.

In particular, the Academy, in its congressionally-mandated role of

recommending reasonable standards for protecting health and safety at the

repository, has questioned EPA’s groundwater protection approach for

Yucca Mountain. The Academy did not propose separate groundwater

protection standards for the repository in its own technical

recommendations for the facility, which were issued in 1995. The

Academy’s November 1999 comments on EPA’s draft standards directly

opposed such an approach, calling it “scientifically unsupported,” adding

little or no public health benefit.22 According to the Academy, EPA has the

authority to establish a separate groundwater limit for Yucca Mountain but

has not presented a technical rationale for doing so. In addition, NRC and

DOE have commented that EPA has not done a comprehensive analysis of

the health benefits and costs of its groundwater approach for Yucca

Mountain. EPA has issued a draft regulatory impact analysis to accompany

its draft Yucca Mountain standards, in accordance with Executive Order

12866, which calls for such an analysis if the regulatory action is significant

(for example, raises novel legal or policy issues). However, the draft

regulatory impact analysis was limited in scope (stating that data were

lacking for a fuller discussion), and the document did not analyze the

specific impact of EPA’s groundwater protection approach for the

repository.

EPA recognizes that the drinking water contamination limits that are to be

applied at the repository are not scientifically up to date. They are based on

1970s-era methods of radiation dose estimation, which have been

superseded. The limits were originally intended to be equivalent to 4

millirem a year of exposure. However, under updated dose estimation

methods, they no longer reflect 4 millirem a year. Instead, using a

commonly accepted dose conversion factor, they reflect varying annual

millirem levels and acceptable risks, and some reflect millirem levels up to

a thousand times lower than average U.S. natural background radiation

levels. A few of the limits are equivalent to well above 4 millirem a year, but

21Under 40 C.F.R. 141, annual concentrations of beta particle and photon activity sources are

limited to no more than a total body or internal organ dose equivalent of 4 millirem a year.

See app. II.

22On the other hand, the Academy found the magnitude of EPA’s proposed 15-millirem-a-year

all-pathway limit to be consistent with the Academy’s own recommendations.
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many are equivalent to fractions of a millirem a year.23 NRC has commented

that because groundwater is expected to be the dominant exposure

pathway at Yucca Mountain, these limits will be the de facto overall

protection standards for the repository.

According to EPA officials, the agency’s proposed standards and

groundwater protection approach for Yucca Mountain are justified on

policy grounds and are technically justifiable as well. The agency has

applied drinking water standards to groundwater at the repository, EPA

officials said, because it desires to protect groundwater as an

environmental resource (for drinking water and irrigation needs) in a

region where the population has been growing quickly. In addition, the

agency has a general policy of coregulating chemicals and radionuclides in

groundwater, and EPA officials said the standards for Yucca Mountain

should be in accord with this policy. EPA officials agreed that the agency

has not done a comprehensive analysis of the health benefits and costs of

the agency’s groundwater approach for Yucca Mountain, but they believe

their regulatory approach has fully addressed the pertinent overall

technical issues related to setting radiation protection standards for the

site. They said they are developing an expanded regulatory impact analysis

to accompany their final standards, which will not constitute a specific

technical rationale for their extra groundwater protection approach but

will address technical and cost issues related to the implementation of their

standards, as the Academy recommended.

While recognizing that the drinking water concentration limits to be

applied at Yucca Mountain are out of date, reflecting inconsistent doses

and risks, EPA officials said the agency is in the process of updating the

limits and expects to complete this effort by the fall of 2000. They said that

if the final Yucca Mountain standards are issued before then, the updated

limits will be incorporated into them. The officials noted that under a “no

backsliding” provision of the 1996 Safe Drinking Water Act Amendments,

any updated drinking water standards for radionuclides must maintain

23For example, the limit for Iodine 129, considered a benchmark among the various limits for

Yucca Mountain, is 1 picocurie per liter, or about 0.2 millirem a year; the limit for Nickel 63

is 50 picocuries per liter, or about 0.02 millirem a year, and the limit for Tritium is 20,000

picocuries per liter, or about 0.9 millirem a year. In addition, the limits reflect acceptable

lifetime risks ranging anywhere from less than 1 chance in a million to more than 1 chance

in 2,000 of a person dying from the exposure, using a commonly accepted dose-risk

conversion factor and assuming the linear model holds. EPA points out that most limits fall

within its acceptable risk range of 1 chance in about 10,000 to 1 chance in about a million of

a person getting cancer from the exposure.
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equal or greater levels of public health protection. According to EPA, this

provision precludes the agency from raising any of the concentration

limits, even in attempting to achieve greater uniformity in doses or risks.24

A draft version of the proposed new limits indicates that EPA may not

change any of the limits.25

As EPA and NRC prepare to issue final standards for Yucca Mountain, it is

not evident that the two agencies and the Academy will agree on

appropriate groundwater protection standards for the repository. If they do

not agree, EPA’s final Yucca Mountain standards, expected to be issued in

the summer of 2000, will lack a degree of technical consensus that would

add to their credibility and acceptability. Aware of the conflict between

EPA and NRC over standards for Yucca Mountain, the Congress, in March

2000, passed legislation retaining EPA’s standard-setting authority while (1)

allowing the Academy and NRC to report to the Congress any major

disagreements they may have with EPA’s final standards and (2) delaying

the issuance of final standards for Yucca Mountain until June 2001. On

April 25, 2000, the President vetoed the bill, in part because it would have

limited EPA’s authority to issue radiation standards, and on May 2, 2000, the

Senate upheld the veto.

EPA and NRC Have Issued

Different Standards and

Guidance for Nuclear Site

Cleanup and

Decommissioning

Both EPA and NRC developed nuclear site cleanup and decommissioning

standards in the 1990s, attempting to facilitate the massive national effort

to clean up nuclear contamination at many federal and commercial nuclear

sites—including DOE’s nuclear weapons complex and commercial nuclear

power plants licensed by NRC —that are closing down after decades of

operations. In 1995, EPA drafted cleanup standards reflecting the agency’s

groundwater protection approach, which includes 15-millirem-a-year allpathway protection, plus separate groundwater protection to drinking

water standards. However, the agency withdrew these standards in 1996,

before they were finalized, after other agencies objected to them.

Subsequently, in 1997, EPA implemented the same approach through

24Another technically related groundwater issue is EPA’s prospective choice of a

groundwater scenario for Yucca Mountain, including the point of enforcement (at or how

near to the repository boundary) and appropriate estimated groundwater flow volume. DOE

and NRC officials said a very conservative scenario could severely complicate DOE’s efforts

to do detailed, refined groundwater analysis for the site.

25According to EPA, the new limits are to be based on acceptable risks instead of the current

dose basis of 4 millirem a year.
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Page 21 GAO/RCED-00-152 Radiation Standards

nonbinding Superfund guidance. Also in 1997, NRC finalized its own

cleanup standards—decommissioning standards for its licensees—

reflecting 25-millirem-a-year all-pathway protection.26 In correspondence

with NRC, EPA has objected to NRC’s standard as potentially not

protective in all cases.27 In some cases, both EPA’s and NRC’s approaches

have both been applied to the same site, raising questions about potential

dual regulation.

EPA and NRC have long disagreed on standards for cleaning up and

decommissioning the nation’s nuclear sites. As far back as 1992, the two

agencies signed a memorandum of understanding, agreeing to avoid

unnecessary duplication of regulatory requirements. In 1994, we reported

that EPA and NRC were involved in potentially costly dual regulation of

NRC’s licensees. Our previous report’s recommendation that the agencies

pursue consensus on acceptable risk was a factor in the establishment in

1995 of the Interagency Steering Committee on Radiation Standards, which

is cochaired by EPA and NRC. However, despite numerous staff initiatives

and some progress in cooperation, this committee has not resolved major

issues between the two agencies. The two agencies have continued to use

separate approaches in setting standards for cleaning up and

decommissioning nuclear sites, especially when groundwater protection is

involved. Consequently, perceived dual regulation by EPA and NRC

continues to complicate the cleanup and decommissioning process at some

sites where both agencies’ standards may apply, potentially causing

duplication of effort and regulatory delays, adding to facilities’ compliance

costs, and raising public questions about what cleanup levels are

appropriate and safe.28

26In addition, DOE has issued public protection orders for its nuclear installations that

generally conform to NRC’s approach, including all-pathway protection without extra

groundwater protection, as well as dose reductions to levels as low as reasonably

achievable. DOE has proposed to convert its order into a regulatory standard, but EPA has

opposed the draft standard as inconsistent with Superfund requirements.

27In 1994, NRC considered standards comparable to EPA’s—15 millirem a year, with separate

groundwater protection to drinking water standards—but changed to an all-pathway, 25-

millirem-a-year approach after further analysis and public comments on the proposed rule.

28Also, over the years, differences between EPA and DOE concerning standards and

acceptable risks for cleanups at DOE sites have contributed to regulatory delays and higher

regulatory and cleanup costs while raising public questions about what cleanup levels are

appropriate. See Nuclear Cleanup: Completion of Standards and Effectiveness of Land-Use

Planning Are Uncertain (GAO/RCED-94-144, Aug. 26, 1994).
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Page 22 GAO/RCED-00-152 Radiation Standards

For example, in individual situations at NRC-licensed sites, EPA has

indicated that it might not view cleanups performed to NRC’s standards as

adequately protective under its Superfund guidance. EPA considers such

potentially conflicting situations to be exceptions, not the rule. EPA raised

the matter of the standards’ adequacy twice in 1999 in connection with

nuclear power plants in Maine and Connecticut where the

decommissioning process is under way, and again in connection with the

West Valley, New York, nuclear site, a DOE-operated facility where NRC

has a legislatively mandated regulatory role. In such situations, the licensee

may construe EPA’s involvement as a warning that EPA could reevaluate

the adequacy of a cleanup that has met NRC’s requirements. In the New

England cases, the licensee has thus far responded to the prospect of dual

regulation by proceeding with its decommissioning plans, assuming that it

will be able to comply with both agencies’ standards.29 In the West Valley

case, it remains to be seen whether NRC’s or EPA’s approach will finally be

chosen for the site.

Our 1994 report found that U.S. radiation standards reflected a lack of

federal agency consensus on acceptable radiation risk to the public,

particularly between EPA and NRC. We recommended that the two

agencies take the lead in pursuing interagency consensus on acceptable

radiation risks to the public. In succeeding years, EPA and NRC have

attempted to resolve their conflict over cleanup standards by means of a

memorandum of understanding that would clarify their potentially

conflicting, dual regulation of NRC-licensed sites. In August 1999, the

House Appropriations Committee strongly encouraged the two agencies to

develop such a memorandum and directed them to report to the Congress

by May 1, 2000, on the status of their efforts to do so.

In early May 2000, EPA and NRC informed the Committee by separate

letters that they are developing such a memorandum, although a jointly

drafted version of the memorandum does not yet exist. To date, EPA

officials see such a memorandum as providing an outline of consultation

procedures for EPA and NRC to use during NRC’s decommissioning

process when NRC requests EPA’s assistance. It is unclear whether the

memorandum will consider whether EPA should retain its authority to

conduct a Superfund evaluation of an NRC-licensed or -decommissioned

29The licensee has stated that it can meet more stringent standards of 10 millirem a year,

plus extra groundwater protection to the equivalent of 4 millirem a year, as imposed by the

state of Maine.
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facility when a stakeholder requests such an evaluation. EPA believes it

should retain this authority and has provided guidance to its regional

offices on how to proceed when a stakeholder asks for an evaluation.

According to this guidance, EPA believes that at the vast majority of NRClicensed sites, cleanups that meet NRC’s standards will also meet

Superfund standards. An NRC draft version of the memorandum assumes

that EPA will defer to NRC’s radiological cleanup and decommissioning

standards and regulations and will exempt most NRC-regulated sites from

the application of the Safe Drinking Water Act and Superfund. NRC’s

version reflects the Commission’s view that clearly delineated jurisdictions

for the two agencies are needed.

Costs Vary to Comply

With Different

Radiation Standards

Long-term costs related to complying with current and prospective U.S.

radiation standards have generally not been comprehensively estimated,

but these costs will be immense, likely in the hundreds of billions of

dollars.30 The potential size of these costs is reflected in DOE’s long-term

funding estimates for high-level waste disposal and nuclear cleanup

projects. These estimates total more than $200 billion over many decades

and could increase, according to DOE. In addition, DOE’s, NRC’s, and EPA’s

analyses of individual nuclear sites’ cleanup options show that site-specific

compliance costs can vary significantly depending on the restrictiveness of

the standards. As might be expected, the analyses show that compliance

with more restrictive standards—for example, exposure limits of a few

millirem a year—costs considerably more than compliance with less

restrictive standards—for example, limits of 100 millirem a year. Sitespecific DOE analyses estimate multimillion-dollar cost differences

between less restrictive and more restrictive protection levels, in some

cases. These analyses further show faster rising costs to achieve the most

restrictive protection levels.

30Annual costs and benefits of environmental regulations have been estimated to total many

billions of dollars annually. For example, see R. Hahn, and J. Hird, “The Costs and Benefits

of Regulations,” Yale Journal on Regulation, vol. 8 (1991), pp. 233-78.
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Costs of Implementing HighLevel Waste Standards

To comply with high-level waste standards, DOE has projected multibillion

dollar costs, whether or not the Yucca Mountain repository is developed.

Radiation protection standards for Yucca Mountain have not been

finalized,31 but DOE has estimated funding of over $43 billion (in 1998

dollars) for the total repository system to 2116, in large part to help ensure

that the public is protected from exposure to the waste stored there.

According to DOE’s latest estimates, long-term funding for the repository

could go over $55 billion. Alternatively, if the repository is not built, DOE

has estimated expenditures of about $52 billion to $57 billion to store highlevel waste for 100 years at existing sites around the country. From the

enactment of the Nuclear Waste Policy Act of 1982 through fiscal year 1998,

DOE spent about $7 billion (in 1998 dollars) for its repository program.32

EPA, NRC, and DOE have not estimated the total difference in compliance

costs under the conflicting standards proposed by EPA and NRC for Yucca

Mountain. DOE officials said that most of the projected increases in the

repository’s costs can be associated with design changes resulting from the

combination of EPA’s proposed groundwater standards, the need to

provide the level of confidence in the repository’s performance required for

a rigorous NRC licensing process,33 and the influence of external oversight

advisory bodies and peer review panels. DOE estimated that cost increases

have totaled over $10 billion since 1993 to achieve added confidence that

restrictive performance and radiation protection requirements can be met

over thousands of years. For example, in 1993 a repository-performancerelated increase of $7 billion (in 1999 dollars) came from a design change

involving the use of more robust, cylindrical waste containers.

Furthermore, DOE is considering an additional cost of $3.7 billion (in 1999

dollars) for water-diverting titanium drip shields (over the waste

31DOE officials said that since the 1990s, they have been designing the repository to more

than meet prospective radiation standards that EPA and NRC might issue.

32 At another nuclear waste disposal facility that is already in operation, the Waste Isolation

Pilot Project, where EPA’s transuranic waste disposal standards are operative, DOE projects

funding to 2070 at $7.7 billion. In addition, state compacts and unaffiliated states have to

date incurred almost $600 million in costs for planning and developing potential low-level

waste disposal sites, although no sites have been built. See Low Level Radioactive Wastes:

States Are Not Developing Disposal Facilities (GAO/RCED-99-238, Sept. 17, 1999).

33According to DOE and EPA, NRC’s proposed “reasonable assurance” performance

objective for the repository may be more stringent and costly to implement than the

“reasonable expectation” compliance objective in EPA’s proposed standards. NRC disagreed

that this would necessarily be the case.
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containers) intended to protect the repository from potential water

incursion, as well as to meet EPA’s proposed groundwater protection

requirements in a rigorous NRC licensing process. Further design

enhancements to achieve a cooler repository, which would keep

temperatures in the repository below the boiling point of water, as favored

by the Nuclear Waste Technical Review Board, could add about $2 billion

more to costs. According to DOE and NRC officials, the latest design is

essentially an attempt to achieve a virtually “no radioactive release” facility

at Yucca Mountain. These officials maintain that such a design may not be

needed to implement less restrictive standards such as 15-, 25- , or 100-

millirem-a-year all-pathway exposure limits.

Costs of Implementing

Nuclear Cleanup and

Decommissioning

Standards

Although comprehensive data on the costs of complying with nuclear site

cleanup and decommissioning standards were unavailable, these costs

could be immense in the long term. For example, complying with EPA

Superfund cleanup and other environmental requirements may cost DOE

several billion dollars annually, judging from the fact that the agency’s fiscal

year 1999 appropriation for the overall environmental management and

cleanup of its nuclear facilities was about $5.8 billion. The agency’s

compliance activities could cost hundreds of billions of dollars and could

extend for decades into the future, according to long-term funding

estimates for environmental cleanup projects. The agency has projected

funding for environmental cleanup at its nuclear sites from fiscal year 2000

through fiscal year 2070 to be anywhere from about $151 billion to $195

billion (in 1999 dollars). DOE spent about $52 billion for cleanup from

fiscal year 1989 through fiscal year 1999. The overall bill for DOE’s nuclear

cleanup is uncertain and could go higher. According to DOE, the future

costs of many of its cleanup programs are difficult to quantify because

many projects are still in the planning stage. Moreover, as we noted in 1999,

the data on some sites may not be reliable, in part because many field sites

based their cost estimates on assumed cleanup levels that have not been

finalized.34 In addition, the operators of NRC-licensed nuclear facilities,

including over 100 power plants, may spend over $38 billion for

34See Nuclear Waste: DOE’s Accelerated Cleanup Strategy Has Benefits but Faces

Uncertainties (GAO/RCED-99-129, Apr. 30, 1999). According to DOE, about 85-90 percent of

its environmental management budget is directed toward ensuring compliance with the

large number of legally enforceable cleanup and compliance agreements in place at major

sites around the country. Such compliance involves not only EPA requirements, such as

Superfund, but also any applicable state requirements, as well as DOE’s own radiation

protection orders.
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decommissioning in coming decades, according to the Nuclear Energy

Institute.

Even though EPA, NRC, and DOE generally did not have estimates for all

U.S. nuclear sites of the costs of complying with different cleanup

standards to achieve different protection levels,35 officials from these

agencies said that achieving more restrictive protection levels, especially

the most restrictive levels—in the range below 100 millirem a year—can be

considerably more expensive. To support their statements, they cited

various generic and site-specific cost analyses conducted by DOE, NRC,

and EPA. Our examination of these cost analyses generally confirmed

higher estimated costs to comply with more restrictive cleanup levels for

contaminated soil, as might be expected. Conversely, cost estimates were

considerably less to comply with less restrictive soil cleanup levels. For

example, analyses comparing the costs of achieving EPA’s and NRC’s

conflicting all-pathway cleanup levels—15 millirem a year and 25 millirem a

year, respectively—show cost differences in the millions of dollars for

some sites—and even greater cost differences to achieve cleanup levels

below 10 millirem a year. Analyses also show potential multimillion-dollar

cost differences between the 15 to 25 millirem-a-year range and the less

restrictive 100-millirem-a-year level.

Among the analyses we examined were a generic analysis by NRC to

support its decommissioning standards and numerous site-specific cost

analyses done by DOE in the course of analyzing cleanup options for its

nuclear weapons complex. The estimated costs of meeting different soil

cleanup levels for selected sites are summarized in table 1 and discussed in

more detail in appendix V.

35An exception is a preliminary regulatory analysis done by EPA in 1996 to support its

proposed cleanup standards. The analysis showed incremental cost differences in the low

billions of dollars to meet various cleanup levels below 100 millirem a year. See app V.
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Table 1: Estimated Costs to Achieve Different Soil Cleanup Levels at Selected DOE

Sites and Generic NRC-Licensed Sites

Note: Totals do not represent overall estimates of cleanup costs, which may include costs for activities

other than soil cleanup, including the decontamination and removal of equipment and structures, as

well as liquid waste treatment.

a

5 millirem a year.

b

1 millirem a year. Totals are present values.

c

Generic site.

d

3 millirem a year.

Source: GAO’s presentation of data from DOE and NRC.

As shown in table 1, for the listed sites, the estimated costs to achieve

different soil cleanup levels vary, from hundreds of thousands of dollars in

some cases to hundreds of million dollars in other cases. The cleanup costs

also accelerate faster to achieve the most restrictive levels. For example,

for the Nevada Test Site, from a 100-millirem-a-year baseline, the costs

increase over three times and over six times to achieve the 25-millirem-ayear and 15-millirem-a-year levels, respectively, but over 28 times to

achieve the 5-millirem-a-year level. Similarly, for the Brookhaven facility,

from a 100-millirem-a-year baseline, the costs increase about 53 percent to

achieve the 25-millirem-a-year level, about 77 percent to achieve the 15-

millirem-a-year level, but over 300 percent to achieve the 1-millirem-a-year

level. DOE and NRC officials said the large cost variations for different

sites reflected site-specific factors, including the ratio of soil and building

contamination, exposure and land-use scenarios, and waste disposal

options. Officials said cost factors include not only the degree of on-site

Dollars in millions

Agency/site/

analysis date

Cost of

100 millirem

a year

Cost of

25 millirem

a year

Cost of

15 millirem

a year

Cost of less

than 10

millirem a year

DOE/Nevada Test

Site and test

ranges/1995

35 131 240 1,003a

DOE/Brookhaven

Laboratory waste

facility/1998

15.9 24.4 28.2 64.5b

NRC-licensed

power plantc /1997

0.17 0.31 0.41 1.44d

NRC-licensed

metal extraction

facilityc

/1997

5.30 6.21 7.33 13.86d
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remediation, but also soil sampling and analysis to demonstrate

compliance with standards, as well as procedural and other costs.36

Fewer analyses of the costs of complying with EPA’s extra groundwater

protection approach for nuclear cleanups were available. However, DOE’s

groundwater remediation analyses for aquifers at the Idaho National

Engineering and Environmental Laboratory and at the Brookhaven

National Laboratory showed that the additional costs of achieving drinking

water standards at these sites could approach several hundred million

dollars and a few million dollars, respectively, depending on the

remediation option chosen. (See app. V.)

Conclusions Although conclusive scientific evidence of the effects of low-level radiation

is lacking and may not soon be found, U.S. regulators still have the

challenge of developing radiation standards that represent their best

estimates of acceptable radiation risks to the public. In this regard, as a

national decision on high-level-waste disposal at Yucca Mountain

approaches, and as EPA and NRC both continue to administer the cleanup

and decommissioning of nuclear sites, it is important that the two agencies

agree on protection approaches and policies for these regulatory

applications. However, it does not appear that EPA and NRC will readily

agree on appropriate groundwater protection approaches for Yucca

Mountain. Also, EPA and NRC have been working on a memorandum of

understanding since before August 1999, when the House Appropriations

Committee encouraged them to clarify their conflicting regulatory roles

related to nuclear facility cleanup and decommissioning, with little

progress. Looking back, we note that they have not successfully addressed

this matter since at least 1994, when we recommended that they pursue

consensus on acceptable radiation risks to the public. Given the agencies’

historical differences and lack of recent progress, without congressional

intervention, they may not resolve their differences.

It is of note that EPA and NRC, while disagreeing over appropriate public

protection levels, are both regulating at levels where the harm of radiation

and the health benefits of radiation standards may not be clearly

36These analyses do not consider overall site cleanup costs, which may include many

factors, such as the costs of decontaminating and removing structures and treating liquid

waste. The analyses often estimated hypothetical cancer deaths averted from meeting

various protection levels.
B-284378

Page 29 GAO/RCED-00-152 Radiation Standards

demonstrable. Regulating at these levels, well below the range where

radiation effects have been conclusively verified, is essentially a policy

judgment. Such an approach may arguably be prudent, in accordance with

regulatory use of the linear model, which both agencies endorse. However,

it will also be expensive, because compliance costs accelerate to achieve

the lowest exposure levels, as our work confirms. The potential acceptable

risks, health benefits, and costs of EPA’s and NRC’s differing regulatory

approaches will be of interest to the Congress as it continues to focus on

nuclear health and safety issues of national importance, such as the

proposed Yucca Mountain repository and the cleanup and

decommissioning of federal and commercial nuclear sites. These risks,

benefits, and costs will also affect the public’s belief in and acceptance of

any resolution of their conflicting viewpoints that the two agencies may

achieve.

Matters for

Congressional

Consideration

The congressional committees of jurisdiction may wish to reconcile EPA’s

and NRC’s policy differences on groundwater protection for Yucca

Mountain. Also, in connection with the two agencies’ efforts to complete a

memorandum of understanding relating to the cleanup and

decommissioning of nuclear sites, these Committees may wish to clarify

the agencies’ regulatory responsibilities.

Agency Comments We provided NRC, DOE, and EPA with a draft of this report for their review

and comment. NRC found the report to be fundamentally sound and said it

should help the Congress understand the long-standing differences

between EPA and NRC. NRC supported our conclusions that federal

agencies should agree on decommissioning and high-level waste policies

and approaches to ensure consistent standards and public protection. DOE

found the report to be factual and balanced. EPA disagreed with the report,

in separate letters from its Office of Radiation and Indoor Air and Office of

Emergency and Remedial Response. The Director, Office of Radiation and

Indoor Air, said EPA interprets the information presented in our report

differently, and as a result, EPA disagrees with the report’s conclusions.

The Director, Office of Emergency and Remedial Response, said, among

other comments, that the report inaccurately portrays EPA and NRC as

making little progress in their negotiations on a memorandum of

understanding to clarify the two agencies’ regulatory roles and

responsibilities related to the cleanup and decommissioning of nuclear

facilities. EPA mentioned recent and continuing efforts by the two agencies
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Page 30 GAO/RCED-00-152 Radiation Standards

to better clarify their respective regulatory roles through such a

memorandum. While recognizing these recent initiatives, we note that

since as long ago as 1992, the two agencies have been unsuccessful in

addressing this matter, and on this basis we still question whether the two

agencies’ most recent initiatives will resolve their differences without

congressional intervention.

NRC, DOE, and EPA provided technical clarifications to the draft report,

which we incorporated into the final report where appropriate. EPA’s,

NRC’s, and DOE’s comments and our evaluation of them are included in

appendixes VI, VII, and VIII.

As arranged with your office, unless you publicly announce its contents

earlier, we plan no further distribution of this report until 20 days after the

date of this letter. At that time, we will send copies to the Honorable Carol

Browner, Administrator, Environmental Protection Agency; the Honorable

Richard Meserve, Chairman, Nuclear Regulatory Commission; and the

Honorable Bill Richardson, Secretary of Energy. We will also make copies

available to others upon request.

If you have any questions about this report, please contact me or (Ms.)

Gary L. Jones on (202) 512-3841. Key contributors to this assignment were

Duane G. Fitzgerald and Dave Brack.

Sincerely yours,

Jim Wells, Director, Energy, Resources,

and Science Issues
Page 31 GAO/RCED-00-152 Radiation Standards
Page 32 GAO/RCED-00-152 Radiation Standards

Appendix I

Scope and Methodology ApApenednxidexiIs

To conduct our review of U.S. radiation standards, we obtained testimonial

and written documentation from many dozen recognized scientists in the

field of radiation research and radiation protection, including both active

research scientists and representatives on national and international

radiation protection committees; officials of federal agencies principally

responsible for regulating public radiation protection and conducting

scientific research into the health effects of low-level radiation, including

EPA, NRC, DOE, the Department of Defense, and the Department of Health

and Human Services; state radiation protection officials and the

Conference of Radiation Control Program Directors; officials of radiation

protection organizations, such as the National Council on Radiation

Protection and Measurements, the National Academy of Sciences, and the

International Commission on Radiological Protection; environmental and

nuclear industry representatives; and individual radiation researchers in

government, industry, and academia.

To examine the scientific basis of U.S. radiation standards, we obtained

expert views representing various viewpoints in the controversy over lowlevel radiation and the linear model. In addition, we hired an expert

consultant to help synthesize data and draw conclusions relating to the

status of studies correlating worldwide natural background radiation levels

to cancer rates, as well as their possible implications for setting radiation

standards. The consultant, Dr. Thomas Gesell, Professor of Health Physics,

Idaho State University, is a recognized expert in environmental radiation.

(Results based on the consultant’s work, representing GAO’s views, are

presented in detail in app. IV.) Furthermore, we asked several experts in

the radiation protection field to informally review and comment on the

accuracy of a draft version of our report, and we incorporated their

suggested changes where appropriate.

To examine whether federal agencies have come closer to agreeing on

radiation standards since we reported on this matter in 1994, we obtained

views and documentation from agency officials, the Interagency Steering

Committee on Radiation Standards, and the Conference of Radiation

Control Program Directors. We examined various federal and state

radiation standards, as well as the regulatory and compliance activities of

various federal agencies. However, we mainly focused on prominent

current instances of disagreement between EPA and NRC, over radiation

protection standards for high-level waste disposal and for the cleanup and

decommissioning of nuclear facilities.
Appendix I

Scope and Methodology

Page 33 GAO/RCED-00-152 Radiation Standards

To examine the costs of radiation standards, although comprehensive

estimates of these costs were unavailable, we obtained indications of these

costs through available agency radiation-related cost and funding data. To

examine the costs of different standards and protection levels, although

comprehensive estimates of these differences were unavailable, we

obtained indications of these costs through examining generic and sitespecific agency cost analyses. We especially looked for analyses that

showed estimated costs to achieve different radiation exposure levels, and

we took steps to reasonably ensure that the analyses represented the best

available data. Specifically, we obtained (1) analyses agencies considered

representative of the best available data, (2) information on internal and

external peer review and other quality controls steps that agencies may

have taken in connection with the analyses, and (3) agency officials’ views

on any data limitations in the analyses.

We performed our review between July 1999 and June 2000 in accordance

with generally accepted auditing standards.
Page 34 GAO/RCED-00-152 Radiation Standards

Appendix II

Major U.S. Radiation Standards ApendxiI

a

A picocurie is a trillionth of a curie, which is a commonly used unit of measurement of the activity of

radiation.

b

Radioactivity from human-made radionuclides in community drinking water systems.

c

Lifetime risk of an individual’s getting cancer.

Standard/agency Numerical limit

General standards

General public/NRC (10 C.F.R. 20) 100 millirem/year

Source-specific standards

Uranium mill tailings/EPA, NRC (40 C.F.R. 192; 10 C.F.R. 40, App.

A)

Radium 226, 228: 5 picocuries/gram surface,

15 picocuries/gram subsurface

Radon 222: 20 picocuries/square-meter-seconda

High-level waste operations/NRC (10 C.F.R. 60) 100 millirem/year

Spent fuel, high-level waste, transuranic waste disposal/EPA (10

C.F.R. 191)

All pathway: 15 millirem/year

Groundwater 4 millirem/yearb

Yucca Mountain high-level waste (proposed)/EPA (64 Fed. Reg.

46976)

All pathway: 15 millirem/year

Groundwater 4 millirem/yearb

Yucca Mountain high-level waste (proposed)/NRC (64 Fed. Reg.

8640)

25 millirem/year all pathway

Low-level waste/NRC (10 C.F.R. 61) 25 millirem/year

Drinking water/EPA (40 C.F.R. 141) Radium: 5 picocuries/liter

Gross alpha: 5 picocuries/liter

Beta/photon: 4 millirem/yearb

Uranium fuel cycle/EPA (40 C.F.R. 190) 25 millirem/year

Superfund cleanup/EPA (40 C.F.R. 300) Risk range goals: 1 in 10,000 to 1 in 1 millionc

Decommissioning/NRC (10 C.F.R. 20) 25 millirem/year

Occupational standards

Occupational Safety and Health Administration, NRC, DOE (29

C.F.R. 1910; 10 C.F.R. 20; 10 C.F.R. 835)

5,000 millirem/year
Page 35 GAO/RCED-00-152 Radiation Standards

Appendix III

Examples of Different Models of Low-Level

Radiation Effects ApendxiI

Figure 2 shows different models of low-level radiation effects that could fit

the available research data. The linear model is used and endorsed by

regulators and radiation protection organizations. The threshold model is

preferred by those who interpret the data as showing that there are no

effects below a certain exposure level. The higher-risk model is preferred

by those who interpret the data as showing higher risks than the linear

model. The lower-risk model is preferred by those who interpret the data as

showing lower risks than the linear model.

Figure 2: Four Models of Low-Level Radiation Effects Increasing risk

0 5,000 10,000

Range of

assumed

effects

Range of 

somewhat verified

effects

Range of 

well-verified

effects

Exposure in millirem

Higher risk model

Linear model

Lower risk model

Threshold/hormesis model
Page 36 GAO/RCED-00-152 Radiation Standards

Appendix IV

Overview of Epidemiological Research on

Low-Level Radiation Effects ApendxiIV

Epidemiological research has been part of the scientific basis for the linear

model and radiation standards. However, epidemiology may not soon fully

verify or disprove low-level radiation effects. Specific epidemiological

research correlating natural background levels in the United States and

around the world with cancer rates has been generally inconclusive,

showing mixed results. Much of this research has used methodologies that

have been widely considered too limited for the research to be influential in

setting radiation standards.

Several U.S. agencies are involved in epidemiological research on low-level

radiation effects, including the Department of Energy (DOE), the

Department of Health and Human Services (HHS), and the Department of

Defense (DOD). In fiscal year 1999, about $41 million in DOE funding went

for epidemiological research, including about $24 million provided to HHS

for epidemiological and environmental research at DOE’s nuclear sites,

under a 1994 memorandum of understanding that established independent

management of such research. (In comparison, in fiscal year 1999, about

$12 million for radiobiological research was funded within DOE’s Office of

Biological and Environmental Research, and DOD provided an estimated

$11 million for radiobiological research at its Armed Forces Radiobiology

Research Institute.)

Japanese and Worker

Studies

Epidemiological results have been a key basis for the linear model,

including the study of over 85,000 Japanese survivors of the Hiroshima and

Nagasaki bomb blasts. The United States has for many years participated in

this study, conducted by the international Radiation Effects Research

Foundation, with funding by DOE—$14 million in fiscal year 1999—

through the National Academy of Sciences. The still-continuing study has

helped to establish the effects of radiation at levels above 10,000 millirem,

for which the data show a relationship between exposures and health

effects that is generally consistent with a linear model. With a considerable

degree of inherent uncertainty, scientists have extrapolated this

relationship to the low-level radiation range as well. Based in large part on

the Japanese data, major radiation protection organizations have endorsed

the assumption of a linear dose-response relationship at far lower public

exposure levels, down to those commonly regulated—100 millirem a year

and below.

Some scientists have questioned the foundation’s work, asserting that the

study understates radiation risk because it necessarily focuses on bomb

survivors, who likely were the healthiest of the blast victims. Others assert
Appendix IV

Overview of Epidemiological Research on

Low-Level Radiation Effects

Page 37 GAO/RCED-00-152 Radiation Standards

that the important neutron component of the estimated Hiroshima dose is

questionable, calling into doubt the overall Hiroshima-Nagasaki dose

estimates dating from 1986. Recognizing that the Japanese data have

historically been central to radiation risk estimation and that credible

Hiroshima and Nagasaki dose estimates are needed, DOE and the National

Academy of Sciences are conducting a reassessment of the Hiroshima

neutron doses. Results are expected in late 2000. According to DOE, it is

likely that new Radiation Effects Research Foundation dose estimates for

Hiroshima and Nagasaki will be derived and that they will be issued in

2001.

In addition, there have been many epidemiological studies of U.S. and

foreign nuclear workers, medical patients, miners, and others exposed to

various levels of low-level radiation. For example, historically DOE has

funded over 40 epidemiological studies of radiation effects on workers at

sites in the U.S. nuclear weapons complex. According to DOE, the results

have shown elevated cancer levels from chronic exposure at some sites,

among the most highly exposed workers, although the results have been

inconsistent and, looking complex-wide, DOE has not found a clear pattern

of excess risk for any specific cancer type. In general, epidemiological

studies of workers and other groups have the limitation of attempting to

follow research populations that may be too small to give statistically

powerful or conclusive results about very low radiation doses, and

sometimes the studies do not follow populations over a long enough period

of time, according to researchers and agency officials.

Studies Correlating

Natural Background

Radiation With Cancer

Rates

Epidemiological studies have been involved in the controversy over lowlevel radiation effects because many such studies have attempted to

statistically correlate natural background radiation levels (principally

radon) in the United States and around the world with local cancer rates. A

premise in the controversy is that in places with higher background

radiation levels, the studies should show elevated cancer rates if there is a

linear relationship between low-level exposures and health risks. Some of

the studies have focused specifically on areas with the highest natural

background radiation levels. In some places, these levels are four or five

times as high as average U.S. levels. Two types of studies have been

conducted. One type relates regional rates of disease, often obtained from

published vital statistics, to measures of regional radiation levels. These are

called ecologic studies. The other type obtains disease data by direct

interviews of individuals or their representatives and by direct

measurement of radiation exposures. These are called analytic studies.
Appendix IV

Overview of Epidemiological Research on

Low-Level Radiation Effects

Page 38 GAO/RCED-00-152 Radiation Standards

Analytic studies can be prospective, following populations and current

exposures for future outcomes, or retrospective, comparing current

outcomes to past exposures.

For this review, we hired a consultant, Dr. Thomas Gesell, Professor of

Health Physics, Idaho State University, a recognized expert in the field of

environmental radiation, to identify and summarize worldwide ecologic

and analytic studies of natural background radiation or radon. Through his

work, we found that many ecologic and analytic studies have been done in

the United States, Europe, Asia, and South America. Some focused mainly

on radon effects, and others focused more broadly on overall natural

background radiation effects. The results of such studies differ and are

inconclusive overall. Most showed no evidence of elevated cancer risk, but

a minority did show slightly elevated cancer risks. Taken together, the

studies may suggest that low-level radiation effects are either very small, or

nonexistent. Scientists have disputed the importance of such studies in

determining low-level radiation effects. A factor in the dispute is the

methodological difficulty of performing meaningful epidemiological

studies of cancer rates in populations exposed to chronic low-level

radiation doses. In many cases the population being studied is limited in

size, and the cancer effects being pursued are small, making them difficult

to detect among all cancers in the population.

In most places on earth, natural background radiation (excluding radon)

varies within about a factor of four, and cosmic radiation varies by about a

factor of two in the elevations where most of the world’s population lives.

Average world natural background radiation levels are about 240 millirem a

year (including radon), and about 300 millirem a year in the United States.

Particularly high concentrations of natural background radiation have been

reported in Brazil, India, China, and Iran. For example, there are areas of

elevated levels in Brazil, one along the coast (Guarapari) and another in the

interior (state of Minas Gerias); in the Kerala area, India; in Yangjiang

County, southwest Guangdong Province, China; and in Ramsar, Caspian

coast, Iran. In some of these areas, mean annual doses can be more than

double average U.S. levels, and hot spots into several thousand millirem a

year have been reported. In the United States, natural background levels

are over three times higher in the Rocky Mountains than along the Gulf

Coast.

With the help of our expert consultant, we examined 82 ecologic and

analytic studies of natural background radiation or radon, in the United

States and around the world. Of these studies, 45 were directly radon
Appendix IV

Overview of Epidemiological Research on

Low-Level Radiation Effects

Page 39 GAO/RCED-00-152 Radiation Standards

related. The studies examined a variety of different types of cancer, and

some examined cancer effects on children, while others examined genetic

effects. Results of the studies varied, and we did not independently assess

their quality. Some reported statistically significant results—elevated

cancer rates, no elevation in rates, or a negative correlation—and others

reported inconclusive results. (Some lacked basic information for

assessing their quality.) Of 67 radon-related cancer studies, 22 reported

results indicating a statistically significant correlation between natural

background radiation or radon and cancer rates, while 45 found no such

correlation (including 8 that found a negative correlation), and 4 were

inconclusive. Others reported statistically significant chromosomal

aberrations in subjects, but not cancer correlations.

In 1999, the National Academy of Sciences issued a report on the health

effects of radon exposure, called BEIR VI. Of 39 studies examined in the

report, including 19 ecologic studies, 17 studies reported a positive

correlation between radon and lung cancer, and 15 reported no correlation.

Three reported a negative correlation, including a 1995 ecologic study by

Bernard Cohen, University of Pittsburgh, of radiation-cancer correlations

in 1,601 U.S. counties. The study found a strong tendency for lung cancer

rates to decrease with increasing radon exposures, in sharp contrast to the

increase expected from the linear model. The study and follow-up analysis

took steps to test for over 500 potential confounding factors, including

smoking and other lifestyle factors. The author found no potential

explanation for the discrepancy other than failure of the linear model.

Some critics of the study consider it to be carefully and thoroughly done

but believe that it lacks adequate data to control for smoking or other

factors. Many epidemiologists consider all ecologic studies to be

methodologically inferior to analytic case control studies because the

former compile average statistics, not individual statistics. Some analytic

case control studies have contradicted the Cohen study, including a 1997

meta-analysis (study of studies) involving eight individual analytic studies

of radon and lung cancer. The meta-analysis found a small positive

correlation between indoor radon levels and lung cancer. However, the

meta-analysis also found considerable variance in the eight studies’ results,

and specific lifestyle or socioeconomic confounding factors that would

directly negate the Cohen study’s results have not been isolated, although

various theories have been put forward.
Page 40 GAO/RCED-00-152 Radiation Standards

Appendix V

Costs of Different Radiation Standards ApendxiV

We examined numerous EPA, NRC, and DOE analyses of different nuclear

cleanup options and costs. The analyses generally confirmed that, as might

be expected, compliance costs varied to achieve different radiation

protection levels and accelerated to achieve more restrictive levels. The

analyses were done between 1991 and 1999, and they estimated costs under

varying scenarios to achieve different dose, risk, and contamination levels.1

In particular, we examined several site-specific DOE nuclear cleanup

studies; an NRC environmental impact study of four types of generic NRCregulated facilities, performed to support NRC’s decommissioning

standard; and a draft EPA regulatory impact analysis of the potential

nationwide costs (at 16 generic types of sites) of EPA’s proposed

comprehensive cleanup standards. Selected analyses that showed cost

variations in relation to achieving different millirem levels are discussed

below.

Costs of Cleaning Up to

Different Protection

Levels

Our examination of DOE’s and NRC’s analyses showed potential sitespecific cost differences of millions of dollars, in some cases, between

cleaning up radioactively contaminated soil to 15 millirem a year and

cleaning it up to 25 millirem a year, under various scenarios. (These

analyses do not represent estimates of overall site cleanup costs, which

may include factors in addition to soil cleanup, including remediation

activities such as the decontamination and removal of contaminated

equipment and structures and liquid waste treatment.) EPA’s analysis

showed potential nationwide incremental costs in the low billion dollars to

achieve more restrictive cleanup levels.2 Major analyses that showed cost

variations in the range of 100 millirem a year and below are shown in table

2.

1

Often, in addition to costs, the analyses estimated doses and cancer deaths averted from

meeting various protection levels, using the linear model.

2

EPA quantified soil cleanup costs in the draft analysis. According to DOE’s comments on

the analysis, EPA may have greatly underestimated the potential costs of implementing

EPA’s drinking water standards for groundwater at DOE sites.
Appendix V

Costs of Different Radiation Standards

Page 41 GAO/RCED-00-152 Radiation Standards

Table 2: Potential Costs to Achieve Different Soil Cleanup Levels—DOE’s, NRC’s, and EPA’s Analyses

a

The analysis was part of a feasibility study for a Superfund cleanup of ponds, trenches, and burial

grounds in Area 300, where uranium and other wastes from processing nuclear fuel for Hanford’s

production reactors were disposed of over decades. Under an industrial scenario, the analysis

considered five cleanup options. The totals shown are for the selected cleanup and disposal option

and are present values.

b

Cost not calculated for this level.

c

3 millirem a year.

d

At the site and test ranges (Nellis and Tonapah), plutonium contaminates surface soils over an

estimated 90,000 hectares (at levels above 10 picocuries per gram). The contamination resulted from

atmospheric nuclear tests, as well as safety tests that subjected nuclear devices to conventional

explosives. The analysis was conducted separately from the Superfund process, as a cost-risk-benefit

case study to evaluate a range of cleanup alternatives, using an active institutional controls scenario to

limit costs. An integration model was used to estimate individual risks, population risks, costs (cleanup

costs, costs of worker fatalities), and benefits (including reduced future on-site cancer fatalities). The

totals assume on-site disposal for the Tonapah range waste.

e

5 millirem a year.

f

The analysis supported the Superfund process for the site, in Missouri, where uranium and thorium

ore were processed from 1957 until 1966, contaminating buildings and soil. Under an on-site farmer

scenario, alternative uranium soil cleanup levels were calculated. A 25-millirem-a-year cleanup target

was selected, with an as low as reasonably achievable (ALARA) goal equivalent to 6.7 millirem a year.

g

12 millirem a year.

h

6.7 millirem a year.

i

The facility historically processed, treated, and stored radioactive and hazardous waste. The analysis

was conducted apart from the Superfund process, as an ALARA case study. Using an open space

scenario, the analysis undertook risk optimization to determine the cost savings from the remedial

action, the life-cycle costs for the remedial action, the value of the net dose avoided, and the value of

Dollars in millions

Agency/site/analysis date Estimated soil cleanup cost

100-millirem-ayear level25-millirem-a-year

level

15-millirem-a-year

level

Less than 10-

millirem-a-year

level

DOE

Hanford process waste areas, 1994a b 14 19 59c

Nevada Test Site and test ranges, 1995d 35 131 240 1,003e

Weldon Spring, 1991f b 0.58 1.4g 2.0h

Brookhaven waste facility, 1998i 15.9 24.4 28.2 64.5j

NRCk

Generic nuclear power plant, 1997 0.17 0.31 0.41 1.44c

Generic fuel fabrication facility, 1997 2.89 6.35 7.83 13.56 c

Generic metal extraction facility, 1997 5.30 6.21 7.33 13.86 c

Generic sealed source facility, 1997 0.08 0.26 0.35 0.64 c

EPA

Generic nationwide sites, 1996l m 1,000 1,500 3,200c
Appendix V

Costs of Different Radiation Standards

Page 42 GAO/RCED-00-152 Radiation Standards

other avoided risks and damages. In the net benefit-cost analysis, net costs resulted at all millirem-peryear levels. The totals shown represent present values.

j

1 millirem a year.

k

The four generic types of NRC-liensed facilities were included in a generic environmental impact

statement supporting the issuance of the agency’s decommissioning standard. The generic

environmental impact statement included analyses of human health impacts, costs, and the costbenefit of the regulatory action, under an unrestricted-use scenario. The totals shown reflect soil

removal and survey costs, based on “real world” soil characterization estimates.

l

The analysis was part of a regulatory impact analysis supporting EPA’s prospective nuclear site

cleanup standard. The analysis addressed incremental soil cleanup cost and health impact differences

nationwide, between a base case (100 millirem a year, absent the proposed EPA standard) and the

regulatory case (assuming promulgation of the EPA standard) for 16 types of reference sites, based on

actual DOE, DOD, and NRC-licensed sites. Results were calculated for three scenarios—upper- and

lower-bound scenarios and an intermediate scenario representing EPA’s best estimate. The totals

shown reflect the intermediate case, representing incremental soil cleanup costs below a 100-millirema-year baseline. The totals represent present values.

mThe 100-millirem-a-year baseline.

As shown in table 2, for individual DOE and NRC-licensed sites, the

estimated differences in compliance costs between the 15-millirem-a-year

and the 25-millirem-a-year levels—reflecting EPA’s and NRC’s all-pathway

standards, respectively—varied widely, from thousands of dollars to over

$100 million. Similarly, the table shows widely varying cost differences

between the 100-millirem-a-year level and lower levels. EPA’s analysis

estimated incremental compliance costs for multiple sites nationwide. As

shown in the table, the analysis found cost differences of over a billion

dollars between the 100-millirem-a-year level and lower levels.

The varied costs in table 2 reflect not only different protection levels but

also different land-use scenarios and site characteristics, among other

factors. For example, the 1995 analysis for the Hanford process waste areas

used an industrial scenario, at a location with a variety of soil and structure

components; the 1995 analysis for the Nevada test ranges used an active

institutional controls scenario, at a large, soil dominated location; and

NRC’s 1997 analysis used unrestricted access scenarios, at generic

industrial sites with substantial on-site structures. According to DOE

analysts, scenarios involving on-site unrestricted, residential, or industrial
Appendix V

Costs of Different Radiation Standards

Page 43 GAO/RCED-00-152 Radiation Standards

use can result in much lower cleanup levels and higher cleanup costs than

scenarios involving restricted or open-space use.3

The analyses also generally showed that cleanup costs accelerated to

achieve the most restrictive protection levels. These accelerating costs can

be shown graphically in the form of a cost-benefit curve, as depicted in

figure 3, for the Brookhaven hazardous waste facility:

Figure 3: Cleanup Costs as a Function of Cleanup Levels—Hazardous Waste

Facility, Brookhaven National Laboratory, 1998

As shown in figure 3, in the Brookhaven analysis, costs were a function of

cleanup levels, increasing gradually, from right to left, from 100 millirem a

year to 15 millirem a year, and accelerating from 15 millirem a year to 1

millirem a year. Conversely, rates of dose reduction (and potential

3

For example, the choice of an open space scenario for the Rocky Flats facility in Colorado

was a factor in the decision to apply a less restrictive plutonium cleanup level there than

was required at the Nevada Test Site. See DOE: Accelerated Cleanup of Rocky Flats—Status

and Obstacles (GAO/RCED-99-100, Apr. 30, 1999). The Rocky Flats plutonium cleanup level

is being reconsidered in response to stakeholders’ concerns, and a preliminary DOE cost

estimate for a many times more restrictive cleanup level showed potential cleanup cost

increases for Rocky Flats in the tens of millions of dollars.

0

10

20

30

40

50

60

70 Cost in millions of dollars

Cleanup objective, millirem per year

1 15 25 50 75 100
Appendix V

Costs of Different Radiation Standards

Page 44 GAO/RCED-00-152 Radiation Standards

associated increased health benefits) decelerated at costs above $30

million. This relationship generally held for many DOE analyses we

examined, including some that expressed cleanup levels in terms of risk

and others that expressed cleanup levels in terms of concentration levels

achieved.4 According to DOE analysts, under the principle of reducing

doses to levels as low as reasonably achievable (ALARA), there is a point or

“elbow” on the cost-curve where an optimal balance between costs and

cleanup level is chosen.

Costs of Groundwater

Cleanup

Agencies generally did not have overall estimates of the cost differences

between achieving NRC’s all-pathway 25-millirem-a-year limit for nuclear

cleanups and achieving EPA’s proposed extra groundwater protection

requirements, based on the agency’s more restrictive drinking water

standards. However, available DOE and NRC analyses showed potential

multibillion dollar cost differences per site to achieve EPA’s standards.

Both NRC and DOE expressed concern that the extra groundwater

protection favored by EPA for nuclear sites could impose multimillion

dollar additional costs annually at sites with groundwater contamination.

NRC, in part, based its concern on an analysis done to support its

decommissioning standard. This analysis showed that at a generic nuclear

site with strontium 90 groundwater contamination, from a baseline of 25

millirem a year, incremental costs using “pump and treat” methods could

be as high as $7 million to achieve a 3-millirem-a-year level (below the

original 4 millirem-a-year drinking water standard, but above the level for

strontium 90 using up-to-date dose estimation methods—0.07 millirem a

year) and an additional $32 million to achieve natural background levels.

(“Pump and treat” means that the water is pumped out of the ground,

treated by various means, and discharged back into the ground.)

Site-specific DOE analyses also indicated incremental costs of many

millions of dollars per site to meet drinking water standards through longterm pump and treat techniques. For example, a 1998 DOE analysis, issued

in concert with EPA and the Idaho Department of Health and Welfare,

showed options for cleaning up the Snake River Plain Aquifer underneath

4

Other analyses included a draft 1999 analysis at two Nevada Test Site locations in the

Tonapah test range; a 1999 analysis at the Energy Technology and Environmental Center,

Santa Susana, California; a 1995 analysis at the Elza Gate, Tennessee, former waste storage

site; and a 1994 analysis at the Ventron, Massachusetts, former uranium compounds

processing facility.
Appendix V

Costs of Different Radiation Standards

Page 45 GAO/RCED-00-152 Radiation Standards

the spent fuel processing facility at the Idaho National Engineering and

Environmental Laboratory. According to the analysis, the costs of using a

pump and treat approach, if necessary to achieve the drinking water

standard for a key radionuclide, Iodine 129, by 2095, could be anywhere

from about $40 million to about $788 million depending on the

aggressiveness of the approach taken.5

Also, a 1998 Brookhaven National Laboratory analysis of pump and treat

options to clean up tritium and strontium 90 in the on-site groundwater

showed that natural attenuation of the strontium 90 for 60 years or more

might meet the drinking water standard for strontium 90 and cost less than

a million dollars for monitoring activities. Alternatively, pump and treat

methods might achieve the drinking water standards in 30 or more years, at

costs of from $5.8 million to $6 million.

5

According to a DOE-Idaho official, a December 1999 record of decision based on the

analysis chose a less expensive aquifer dilution and monitoring approach.
Page 46 GAO/RCED-00-152 Radiation Standards

Appendix VI

Comments From the Environmental

Protection Agency ApendxiVI

See comment 1.

Note: GAO comments

supplementing those in the

report text appear at the end

of this letter.
Appendix VI

Comments From the Environmental

Protection Agency

Page 47 GAO/RCED-00-152 Radiation Standards

See comment 2.

See comment 3.
Appendix VI

Comments From the Environmental

Protection Agency

Page 48 GAO/RCED-00-152 Radiation Standards

See comment 4.

See comment 5.
Appendix VI

Comments From the Environmental

Protection Agency

Page 49 GAO/RCED-00-152 Radiation Standards

The following are GAO's comments on the letter dated June 13, 2000, from

the Director, Office of Radiation and Indoor Air, Environmental Protection

Agency.

1. EPA said the draft report raised the issue of whether the U.S. government

should continue to use the linear model, and EPA said it is following the

consensus of scientific organizations in doing so. EPA also said the lack of

scientific evidence has not led to the agency's regulatory disagreement with

NRC. Rather, according to EPA, the two agencies have made different riskmanagement decisions, based on differing statutory mandates. One of our

report's objectives was to describe the scientific basis for U.S. radiation

standards, which we found to be inconclusive. The report raises no

expectation that the linear model will or should be soon superseded,

pending the existence of better evidence of low-level radiation effects. We

agree that risk management decisions made by EPA and NRC, based on

differing statutory mandates and protective strategies, largely account for

the disagreement between the two agencies. Our report says this.

2. EPA said that in citing low-level radiation as a weak carcinogen, GAO

ignored evidence that ionizing radiation has a much higher probability of

resulting in DNA misrepair than other, more commonplace cell-altering

events. We are aware of such evidence, and in agreement with EPA's

qualifying point, we modified the final report accordingly.

3. EPA said that its groundwater standard is not alone responsible for

driving the cost of the Yucca Mountain project, and EPA's standards have

had little time to influence the overall cost of the program. Our report

mentions several factors, significantly but not exclusively including EPA's

proposed groundwater standard, that have influenced the project's costs to

date and could do so in the future.

4. EPA said it is premature to conclude that a memorandum of

understanding clarifying EPA's and NRC's regulatory roles is unlikely. We

believe that, given the lack of progress by the two agencies since as long

ago as 1992, it is questionable whether they will finalize such a

memorandum. Even if they do, we question whether such a finalized

memorandum will fundamentally resolve the problem between them.

5. EPA said the draft report should have focused more on the relatively

small differences in cleanup costs between the 25-millirem-a-year and 15-

millirem-a-year levels, which EPA and NRC have often argued about. The

scope of our review did not exclude consideration of levels both higher and
Appendix VI

Comments From the Environmental

Protection Agency

Page 50 GAO/RCED-00-152 Radiation Standards

lower than 25 millirem a year and 15 millirem a year. The report shows that

cost differences to achieve these levels vary, depending on the site

involved, and may be small in some cases. However, in relation to the

hundreds of potential cleanup sites that exist nationwide, overall cost

differences between the 25-millirem-a-year and 15-millirem-a-year levels

could be substantial.
Appendix VI

Comments From the Environmental

Protection Agency

Page 51 GAO/RCED-00-152 Radiation Standards

See comment 1.
Appendix VI

Comments From the Environmental

Protection Agency

Page 52 GAO/RCED-00-152 Radiation Standards

See comment 1.

See comment 2.

See comment 2.
Appendix VI

Comments From the Environmental

Protection Agency

Page 53 GAO/RCED-00-152 Radiation Standards

See comment 2.

See comment 3.
Appendix VI

Comments From the Environmental

Protection Agency

Page 54 GAO/RCED-00-152 Radiation Standards
Appendix VI

Comments From the Environmental

Protection Agency

Page 55 GAO/RCED-00-152 Radiation Standards

The following are GAO's comments on the letter dated June 12, 2000, from

the Director, Office of Emergency and Remedial Response, Environmental

Protection Agency.

1. EPA said the draft report appears to evaluate radiological site

contamination and cleanup issues without sufficient acknowledgement

that chemical contamination also exists at almost all of these sites.

Although the subject of our report is radiation protection, the report states

that EPA's policy is to coregulate chemicals and radionuclides, within the

same risk range, rather than to treat them differently. EPA also said its risk

management approach for cleaning up sites is generally consistent with

that of other agencies, including DOE (but not NRC). Although our report

focused mainly on regulatory differences between the two principal

standard-setting agencies, EPA and NRC, the report points out that NRC

and DOE (in its worker protection standards and proposed public

protection standards) generally favor a “top down” approach of setting a

relatively less restrictive dose limit, and then reducing doses well below the

limit in site-specific situations. On the other hand, EPA's Superfund

approach has been “bottom up,” setting a relatively restrictive risk goal but

allowing less restrictive limits in site-specific situations.

2. EPA said the draft report does not adequately discuss recent EPA-NRC

initiatives to avoid potential dual regulation at cleanup sites and

inaccurately portrays the two agencies as making little progress in

negotiating a memorandum of understanding. Our draft report refers to

these recent initiatives, but we modified the final report to make more

specific mention of them. Overall, in relation to the EPA-NRC disagreement

and these initiatives, our report essentially takes the longer view, noting

that since as long ago as 1992, the two agencies have been unsuccessful in

addressing their potentially conflicting roles in site cleanups. On this basis,

it is unclear that the latest initiatives will succeed without congressional

intervention. EPA also said the draft report fails to mention the

administration's opposition to proposed legislative changes, such as

amending Superfund legislation, in lieu of the memorandum of

understanding approach. While we are aware of past legislative proposals,

our report does not delineate what form congressional clarification of the

two agencies' regulatory responsibilities might take.

3. EPA doubted that nuclear site cleanup costs would begin to dramatically

rise at the same cleanup level for different sites. Our report makes no such

assertion. In general, the agency analyses we examined showed faster

rising costs at lower cleanup levels.
Page 56 GAO/RCED-00-152 Radiation Standards

Appendix VII

Comments From the Nuclear Regulatory

Commission ApendxiVI
Appendix VII

Comments From the Nuclear Regulatory

Commission

Page 57 GAO/RCED-00-152 Radiation Standards
Page 58 GAO/RCED-00-152 Radiation Standards

Appendix VIII

Comments From the Department of Energy ApendxiVI

Note: GAO comments

supplementing those in the

report text appear at the

end of this letter.
Appendix VIII

Comments From the Department of Energy

Page 59 GAO/RCED-00-152 Radiation Standards

See comment 1.
Appendix VIII

Comments From the Department of Energy

Page 60 GAO/RCED-00-152 Radiation Standards
Appendix VIII

Comments From the Department of Energy

Page 61 GAO/RCED-00-152 Radiation Standards

See comment 2.

See comment 3.
Appendix VIII

Comments From the Department of Energy

Page 62 GAO/RCED-00-152 Radiation Standards
Appendix VIII

Comments From the Department of Energy

Page 63 GAO/RCED-00-152 Radiation Standards

The following are GAO's comments on the Department of Energy's letter

dated June 13, 2000.

1. DOE raised the question of references to information sources in our draft

report. Our report, for the most part, does not cite technical sources, in

keeping with GAO's policy and the role of our reports as other than

technical treatises, as well as in the interest of report brevity.

2.DOE said there may be different interpretations of the “no backsliding”

provision of the 1996 Safe Drinking Water Act Amendments. We believe

that groundwater protection policy and legal matters, including the specific

“no backsliding” provision, will be of interest to the congressional

committees of jurisdiction in any efforts they may wish to undertake to

reconcile EPA's and NRC's regulatory approaches.

3. DOE said the draft report did not address the integrated health risk or

detriment associated with or averted by the standards and associated

cleanup levels, and it pointed out that risk reductions associated with

cleanup efforts may provide little if any health benefit. Our report

recognizes that agencies routinely calculate hypothetical cancer deaths

averted in achieving cleanup levels. However, we regard such calculations

with caution because they are based on the linear model, and therefore we

did not highlight such calculations in our report.

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