~lnitctd States Genwal Accounting Offiw Report -to Congressional Requesters NUCLEAR WASTE Quarterly Report as of December 31, 1989 United States GAO General Accounting Office Washington, D.C. 20648 Resources, Community, and Economic Development Division B-202377 April 30,lQQO The Honorable J. Bennett Johnston Chairman, Committee on Energy and Natural Resources United States Senate The Honorable James A. McClure Ranking Minority Member Committee on Energy and Natural Resources United States Senate On March 26,1984, you requested that we provide quarterly status reports on the implementation of the Nuclear Waste Policy Act of 1982 (NWPA). The act required the Office of Civilian Radioactive Waste Man- agement within the Department of Energy (DOE) to implement a federal program for the safe and permanent disposal of high-level nuclear waste in one or more geologic repositories. It also assigned responsibility for licensing and regulating repositories to the Nuclear Regulatory Commis- sion (NRC) and development of environmental standards for disposal of these wastes to the Environmental Protection Agency (EPA). An NRC deci- sion to license a repository must be based on a determination that the proposed repository complies with both EPA'S standards and NRC'S regulations. In November 1989 NRC staff questioned whether it is possible to satis- factorily implement, in a repository licensing proceeding, an EPA stand- ard on long-term containment of radioactive wastes. This report addresses that issue and its implications for DOE'S program to determine if a candidate site at Yucca Mountain, Nevada, is suitable for a nuclear waste repository. Results in Brief ard may be written in such a way that it may be difficult, if not impossi- ble, for DOE to satisfactorily demonstrate compliance with the standard in an NRC licensing proceeding. The standard establishes limits on the cumulative releases of radioactive materials to the environment over a lO,OOO-yearperiod and requires that DOE demonstrate that the probability of exceeding these limits is acceptably small. The specific concern is that limitations and uncertainties in the methods and data for making the necessary numerical calculations-such as predicting the occurrence of uncertain events like earthquakes over the long period of Page 1 GAO/RCED-90-130Nuclear Waste Quarterly, Dec. 31, l@SB B202377 time-could lead to lengthy licensing delays unless EPA and/or NRC pro- vide sufficient guidance on acceptable methods for addressing these lim- itations and uncertainties. NRC'S staff has taken initial steps in what it expects to be a collaborative process with EPA to develop additional guidance on how DOE is to demon- strate whether or not the Yucca Mountain site complies with the con- tainment standard. Of particular concern to the staff is that emphasis maintained on the quality of the scientific work that supports the numerical results of DOE’Scompliance analyses. Furthermore, both NRC and EPA expect that DOE'S experience over the next several years in dem- onstrating that its new repository for certain defense wastes--DOE’s Waste Isolation Pilot Plant (wrPP)-complies with EPA'S standards should provide valuable insights into the problems that can be expected in dem- onstrating compliance with the containment standard for an NRC- licensed repository. NWPA, as amended, requires DOE to characterize (investigate) the Yucca Background Mountain site and, if it is found suitable, to apply to NRC for a repository license. DOE must satisfactorily demonstrate to NRC that the combination of the site and the repository design complies with EPA'S standards and NRC'S regulations. WE would demonstrate compliance by collecting and analyzing data; developing, validating, and using predictive models; and assessing the potential repository’s expected performance. Until DOE applies for a license, NRC'S role in the program is limited to providing regulatory guidance and oversight of DOE'S program. EPA'S containment standard relies on the novel approach of using numer- ical probabilities to establish requirements for containing radioactivity within the repository. Specifically, cumulative releases of radioactivity from a repository to the environment for 10,000 years must have a like- lihood of less than 1 chance in 10 of exceeding limits established in the standard and a likelihood of less than 1 chance in 1,000 of exceeding 10 times the limits. EPA does not require absolute proof that the standard can be met; rather, it established a test of “reasonable expectation” of compliance based on “practically obtainable” information and analysis. EPA added this qualifying language to its standard in 1986 after NRC had objected to the unqualified standard proposed by EPA in 1982. NWPA required NRC to establish licensing regulations that are not incon- sistent with EPA'S standards. NRC issued its regulations in 1981 and 1983. Page2 GAO/RCED-SO-180 Nuclear Waste Quarterly, Dec. 31,1989 0-202277 Although NRC has had substantial experience in licensing nuclear reac- tors and related facilities, licensing a geologic repository for nuclear waste will be a new experience. Moreover, NRC has had only limited reg- ulatory experience with standards that are based on numerical probabilities. For example, NRC’S nuclear power regulations are gener- ally qualitative in that determining compliance with the regulations ulti- mately rests on engineering judgments. Of special concern to NRC’S staff is whether EPA’S probabilistically-based EPA’s Containment containment standard can be implemented without paralyzing a reposi- Standard Could Affect tory licensing proceeding with litigation over numerous details of DOE’S Waste Program analysis supporting compliance with the standard. Specifically, the staff believes that the standard can be implemented successfully in a licens- Success ing proceeding only if the inherent uncertainties involved in making long-term projections of repository performance can be satisfactorily taken into account. The contrasting approaches taken by EPA and NRC in developing the con- tainment standard and nuclear power plant safety goals, respectively, illustrate the NRC staff’s concern. In 1986, NRC established two safety goals that broadly define acceptable levels of risk from operation of nuclear power plants. The goals are stated in qualitative terms; specifi- cally, there should be no “significant” additional risk to either individu- als or to society from normal nuclear plant operations and accidents. To help implement the goals, NRC established two safety objectives in which risks are to be calculated numerically and expressed as a percentage of other, non-nuclear, risks to individuals and society.’ Because of the size- able uncertainties in the analytical methods and gaps in the data used to calculate risks, however, NRC decided that (1) the safety objectives must be subordinate to the qualitative safety goals and (2) analyses of compli- ance with the safety goals may not be used as the sole basis for licensing decisions. EPA took the opposite approach in developing its containment standard in that it established, as the centerpiece of the standard, specific probabilities that cumulative releases of radioactive materials will not exceed established limits. EPA then qualified this numerical standard to recognize the inherent uncertainty and limitations in the required analy- sis with its test of reasonable expectation. ‘NRC definesrisk as a mathematicalexpressionof the probability that an event will occurmultiplied by the estimatedconsequences(effects)of that event. Page 3 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 R-202377 r NRC'S staff believes that additional clarification and guidance from the NRC Commissioners and EPA are needed to decide how qualitative techni- cal judgments are to be used by DOE in demonstrating compliance with EPA'S containment standard. The staff plans to identify and resolve potential implementation problems with the standard and encourage EPA to clarify the standard. This would be accomplished through NRC and EPA staff interaction and possible amendments to EPA'S regulations. Also, NRC would amend its existing regulations, conforming them with EPA'S stan- dards, and may issue new rules aimed at reducing technical licensing impediments. An advisory committee to NRC, the Advisory Committee on Nuclear Waste, did not agree that the NRC staff’s proposed course of action is sufficient to resolve implementation issues with EPA'S containment and other standards.2 In a December 21, 1989, letter to the Chairman NRC, the advisory committee said that it had continuing doubts about whether compliance with the EPA standards could be effectively demon- strated for a specific repository site, even with the present qualification of “reasonable expectation” of compliance. According to officials of the committee, the Commission subsequently asked the committee to pro- vide it with additional information on the committee’s basis for this objection and to recommend a possible solution to the standards-imple- mentation issue. DOE has a formidable task in demonstrating if a repository at Yucca ChallengesDOE Faces Mountain can safely isolate waste from the environment over 10,000 in Complying With years. In fact, DOE recently extended by 7 years its repository develop- EPA Containment ment schedule because, in part, of the scientific challenge of adequately investigating the site. According to DOE'S December 1988 site characteri- Standard zation plan, it will demonstrate compliance with the containment stand- ard by conducting performance assessments of the natural features and man-made components of the repository.3 These assessments are to be based on various computerized, conceptual models describing the char- acteristics of the Yucca Mountain site and knowledge of the processes and events that could occur at the site. “The Advisory Committeeon NuclearWaste,establishedin 1988,is the principal advisorto the NRC Commissioners in nuclearwastematters. %OE definesperformanceassessment as any analysisthat predictsthe behaviorof a systemor com- ponentof a systemunder a given set of constantor transientconditions. Page 4 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 R-202377 NRC and others, including a group representing utilities who operate nuclear power plants, have commented on DOE'S site characterization plan. According to NRC'S staff, current information on the Yucca Moun- tain site is inadequate to determine whether meaningful probability esti- mates can be developed for that site; therefore, this major issue should be resolved as early as practicable during site characterization. For example, in its comments on DOE'S plan, NRC staff said that DOE should assign high priority to investigating whether the site is subject to unac- ceptably high chances of disruption due to occurrences of volcanic activ- ity, faulting, or seismic movements. The utility group believes that DOE's site characterization plan does not reflect a full appreciation of, and concern for, difficulties that will be encountered in reducing uncertainties about the site. According to the group, difficulties with modeling are likely because heavy reliance must be placed on the judgments of experts to interpret site data and to pre- dict site conditions for 10,000 years, and there is likely to be disagree- ment on these interpretations. Also, challenges to expert judgments can be difficult to resolve. NRC'S advisory committee raised related concerns about DOE'S site char- acterization program. In a July 1989 letter to the Chairman, NRC, the advisory committee stated that DOE was not giving sufficient emphasis to limitations in its data collection techniques regarding preliminary site characterization activities at Yucca Mountain, The committee said that uncertainties and limitations in the data used to justify conclusions will be the center of most repository contentions and that planning for man- agement of the uncertainties and limitations by DOE is essential. EPA and NRC believe that DOE'S future assessment of the performance of its WIPPfacility, located near Carlsbad, New Mexico, may provide valu- able insights into how readily EPA'S containment standard can be imple- mented in a repository licensing proceeding. The WIPP project was initiated in 1981 when DOE decided to develop a mined geologic reposi- tory to store transuranic waste generated in its defense-nuclear activi- ties.4 The WIPP facility must adhere to EPA'S disposal standards; however, DOE,and not NRC, is responsible for deciding whether or not the facility meets EPA'S standards. 4Transuranicwasteis trash that typically containssmall amountsof long-livedand hazardousradio- active elements,such as plutonium. Page 5 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 R-202377 Both EPA and NRC are concerned that if DOE’S experience with WIPP indi- cates that EPA’S standards are unworkable, the standards should be clar- ified or modified to allow NRC to make a reasoned licensing decision on DOE application to construct a repository at Yucca Mountain or else- where. EPA, in commenting on a DOE draft supplemental environmental impact statement for WIPP, urged DOE to publish its performance assess- ment for WIPP so that the public can review and comment on it. Also, NRC’S staff has noted that a demonstration that a real repository can achieve compliance with EPA’S containment standard could help develop performance assessment capabilities at Yucca Mountain. On March 22, 1990, the Nuclear Waste Technical Review Board, created Recent Related Events by the Nuclear Waste Policy Amendments Act of 1987, submitted its first report to the Congress on DOE’S nuclear waste disposal program. Among many topics addressed in its report, the Board noted that the federal government is simultaneously embarking on two ventures: (1) effort to characterize the Yucca Mountain site and determine its suitabil- ity and (2) an evolving process of developing regulations that will impact on site characterization activities and a repository’s design, con- struction, and operation. Concerning the first initiative, the Board recommended that DOE proceed as rapidly as possible to develop the needed methodology for perform- ance assessment and to begin making preliminary performance calcula- tions with available scientific information and data. The Board believes that an early application of performance assessment techniques may help DOE identify critical problem areas in a timely manner and might demonstrate the suitability-or unsuitability-of the site at an earlier date. Concerning the second initiative, the Board listed seven areas of concern based on its review of the initial working draft of EPA’S revised disposal standards. For example, the Board noted that it is not apparent how geologic uncertainties and limitations are to be characterized in deter- mining probabilistic computations and what burden of evidence is needed to meet the standards’ requirements. Although DOE has primary responsibility for achieving the nuclear waste Observations v disposal objectives of NWPA, the roles assigned to EPA and NRC, and the potential effects that actions by these agencies could have on achieving NWPA’S objectives, are critical to the program’s success. DOE must design Page 6 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 E202377 and conduct its site characterization program at Yucca Mountain to demonstrate to NRC that the site and repository design comply with EPA'S standards and NRC'S regulatory requirements. Unless EPA and NRC can resolve the latter’s concerns about EPA'S contain- ment standard, demonstrating that a proposed repository complies with the standard might not be possible and could result in a lengthy and potentially unsuccessful NRC licensing proceeding. The potential impact of NRC'S concern is highlighted by the contrast between its reactor safety goals and EPA'S containment standard. NRC does not permit quantitative objectives underlying its safety goals to be used as the sole basis for regulatory decisions because of inherent uncertainty in the calculations of risks. Compliance with EPA'S standard, on the other hand, requires numerical calculations of the probabilities of exceeding specified release limits, EPA'S approach to the containment standard raises questions about whether NRC could license a repository that meets, with a high degree of assurance, all EPA and NRC criteria except for the containment standard. In such a case, would the proposed repository be disqualified? Also, if DOE'S analysis shows that the proposed repository only marginally com- plies with EPA'S standard, could uncertainty in the analysis disqualify the repository? Because of DOE'S new extended repository development schedule, there is time to address the containment standard issue before DOE character- izes the Yucca Mountain site and applies to NRC for a construction license. However, NRC'S and EPA'S progress in resolving concerns about the standard bears watching by interested parties because the resolution may also affect DOE'S site characterization program. One potentially important contributor to resolution of the containment standard issue is DOE'S future assessment of WIPP'S performance. Although much about this facility differs from a potential repository at Yucca Mountain, DOE must demonstrate in the same general way-data collection and analysis; development, validation, and use of models; and an overall assessment of the facility’s expected performance-that WIPP complies with EPA'S standards. Therefore, it is important that NRC and EPA have complete and timely access to all DOE data and analyses that are used in preparing the WIPP performance assessment. This would per- mit the agencies to take advantage of whatever lessons can be learned from DOE'S experience in applying EPA'S standards to an actual repository. Page 7 GA0/RCED8&130 Nuclear Waete Quarterly, Dec. 31,1989 B-202377 Methodology mented satisfactorily in a repository licensing proceeding conducted by NRC, we reviewed the NRC staff’s October 17, 1989, paper addressing the issue. We also attended the November 21,1989, briefing of NRC'S Com- missioners by their staff on this issue and obtained and reviewed a tran- script of the meeting. We also reviewed EPA'S final standards for disposal of nuclear waste in repositories issued in September 1986, a January 31, 1990, working draft of EPA'S proposed revised standards, NRC'S regula- tions on high-level nuclear waste repositories, and its safety goals policy statement for nuclear power plant operations. Finally, we reviewed per- tinent parts of DOE'S site characterization plan for Yucca Mountain and comments on the plan by NRC, its Advisory Committee on Nuclear Waste, and a group representing utilities that operate nuclear power plants. We discussed the facts presented here with cognizant officials of DOE and NRC, and we incorporated their comments where appropriate. Our work was performed between November 1989 and February 1990. Appendix I discusses the development of EPA'S environmental standards for nuclear waste disposal and NRC'S actions concerning the containment standard. Appendix II discusses DOE'S plans to implement EPA'S stan- dards at Yucca Mountain and at WIPP. We are sending copies of this report to the Chairmen of the Senate Com- mittee on Governmental Affairs, the House Committee on Government Operations, and the House Committee on Energy and Commerce; the Secretary of Energy; the Chairman, Nuclear Regulatory Commission; the Administrator of EPA; and other interested parties. If you have any ques- tions, please contact me at (202) 275-1441. Major contributors to this report are listed in appendix III. Victor S. RezendesV Director, Energy Issues Page 8 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Page 9 GAO/RCED-99-139 Nuclear Waste Quarterly, Dec. 31,1989 ~-, contents Letter Appendix I 12 Issues Concerning Background Can EPA’s Containment Standard Be Effectively 12 16 Development of Implemented? Environmental Standards for Nuclear Waste Disposal Appendix II 23 Challenges DOE Faces DOE’s Plans to Comply With EPA’s Containment Standard WIPP May Provide Valuable Insights to Implementing 23 27 in Complying With Containment Standard EPA’s Containment Standard Appendix III Major Contributors to This Report Abbreviations ACNW Advisory Committee on Nuclear Waste ACRS Advisory Committee on Reactor Safeguards C.F.R. Code of Federal Regulations DOE Department of Energy EPA Environmental Protection Agency GAO General Accounting Office NRC Nuclear Regulatory Commission NWPA Nuclear Waste Policy Act RCED Resources, Community, and Economic Development Division WIPP Waste Isolation Pilot Plant Page 10 GAO/RCED-90-130Nuclear Waste Quarterly, Dec. 31,1989 Page 11 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Ppe kiiks ConcerningDevelopmentof Ehvironmental Standardsfor Nuclear waste Disposal NRC and others have continuing concerns that one of the EPA'S standards for nuclear waste disposal might paralyze or even block NRC'S licensing process for nuclear waste repositories. The standard requires numerical projections of the probability that harmful radiation will escape from underground nuclear waste repository into the environment over a lO,OOO-yearperiod. At issue is whether EPA'S long-term containment standard that requires predictions be made of highly uncertain events, such as earthquakes, flooding, and fires, can be used effectively in a repository licensing proceeding. NRC anticipates that the DOE may have difficulty in demonstrating compliance with the standard before a licensing proceeding because the standard may emphasize the bottom- line numerical results of DOE'S analysis, rather than the quality of the scientific work supporting the analysis. EPA'S use of a probabilistic standard contrasts sharply with the regula- tory approach NRC took in developing safety goals for nuclear power plants. Because of the limitations and uncertainties in calculating the risks to individuals and to society from nuclear power plant operations, NRC subordinated such calculations to qualitative statements of its safety goals. In contrast, EPA'S containment standard sets out a quantita- tive standard and then qualifies the standard to recognize the inherent limitations and uncertainties in establishing compliance with the standard. NWPA established a federal program and policy for management of Background highly radioactive nuclear waste administered by DOE. The act mandated that the agency develop, site, construct, and operate one nuclear waste repository and select a site for a second repository. Subsequently, in December 1987 the Congress amended the act by, among other things, directing DOE to characterize (investigate) only one site-Yucca Moun- tain, Nevada-and deferring activities on a second repository until the twenty-first century. NWPA also assigned key responsibilities to EPA and NRC. EPA was directed to issue standards for protection of the general environment from releases of radioactive material in nuclear waste repositories. NRC was directed to issue technical requirements and criteria for use in approv- ing or disapproving any DOE applications for authorization to construct and operate nuclear waste repositories. NRC'S technical requirements and criteria must not be inconsistent with EPA'S standards. Page 12 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix I Iseues Concerning Development of Environmental Standarde for Nuclear Waste Disposal Following site characterization, if DOE determines that Yucca Mountain is suitable for a nuclear waste repository, it will recommend selection of the site to the President. If the site is eventually selected, DOE will use the information acquired during site characterization to prepare a license application to NRC. To obtain a repository license from NRC, DOE must demonstrate that the site and proposed repository comply with EPA'S standards and NRC’S regulatory requirements. EPA’s Standards EPA’S environmental standards for management and disposal of nuclear waste in geologic repositories are in two sections.’ The management part of the standards-subpart A-addresses waste storage operations. The disposal part-Subpart B-establishes four standards for disposal of nuclear waste as follows: . Containment requirements: cumulative releases of radioactive materials from a repository to the environment for 10,000 years after disposal shall have a likelihood of less than 1 chance in 10 of exceeding limits established in the standard, and a likelihood of less than 1 chance in 1,000 of exceeding 10 times the limits.2 . Individual protection requirements: exposures of radiation to individual members of the public for 1,000 years must not exceed specified limits. l Groundwater protection requirements: limits are placed on the concen- tration of radioactivity for 1,000 years after disposal from the reposi- tory to a nearby source of groundwater that (1) currently supplies drinking water for thousands of persons and (2) is irreplaceable (i.e., no reasonable alternative source of drinking water is available to that population). l Qualitative assurance requirements: these are prescribed technical or institutional procedures or steps providing confidence that the contain- ment requirements are likely to be met.3 In developing its disposal standards, EPA made a clear distinction between the containment requirements and the individual and ground- water protection requirements. The latter two standards primarily ‘EnvironmentalStandardsfor the Managementand Disposalof SpentNuclearFuel, High-Leveland TransuranicRadioactiveWastes.Final Rule(40 C.F.R.part 191). “Although EPA recognizedthat radioactivity could be hazardousbeyond10,000years,it said that a disposalsystemcapableof meetingrequirementsfor 10,000years after disposalwould continueto protect the environmentwell beyondthis period. :‘Theserequirementsapply only to DOErepositories,suchas WIPP,that are not licensedand regu- lated by NRC. Page 13 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix I Issues Chncerulng Development of Envhumental Stand- for Nuclear w&a! Disposal require DOE to make informed technical judgments of compliance based on traditional engineering and analytical techniques. DOE'S judgments may also take into account such factors as systematic predictions of the probability that certain events would occur and measurements of their associated risks. These two standards also require that DOE make deter- minations of compliance with the limits imposed by the standards based upon the predicted “undisturbed performance” of the repository. Under this criterion, DOE is not obliged to take into account relatively unlikely processes and events that may disrupt the repository from performing as intended, such as human intrusion (for example, inadvertent drilling into the repository) or natural events (earthquakes, flooding, and fires). In contrast, EPA linked compliance with its containment requirements to quantitative (numerical) projections of how much radiation is likely to be released to the accessible environment for 10,000 years after dis- posal. In the scientific community, EPA'S containment standard is referred to as a “probabilistic” standard because compliance with the standard hinges on calculating the probabilities that potentially impor- tant events will occur and multiplying the probabilities by predictions the consequences (such as in terms of releases of radioactive materials to the environment) of those events. Similar to the individual and groundwater protection standards, EPA'S containment standard assigns limits to the total amount of specific radioactive materials that can be released into the accessible environment.4 Unlike the other two stan- dards, however, the containment standard also states that compliance with the standard requires a demonstration that the probability of exceeding the limits is less than 1 chance in 10, and that the probability of exceeding 10 times the limits is less than 1 chance in 1,000. Projec- tions of the total releases must include releases resulting from processes and events that are normally expected to occur and those that occur from disruptions to the repository site by both natural phenomena and human-induced events which have at least 1 chance in 10,000 of occur- ring over 10,000 years. In July 1987, the U.S. Court of Appeals (First Circuit) withdrew and remanded the disposal standards to EPA to reconcile provisions related groundwater contamination with its safe drinking water standards promulgated under authority of the Safe Drinking Water Act. The Court also found no basis for the l,OOO-year period of the individual protec- tion standard and inadequate notice and comment opportunity of the 4Thereleaselimits of quantitiesof radioactivematerialsare found in appendixA to the EPA standards. Page 14 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix I Issues Concemhg Development of Environmental Standards for Nuclear Waste Dbpoeal groundwater protection standard. The Court did not find defective EPA’S containment standard. EPA plans to propose new disposal standards in late 1990 and anticipates a final rule in mid-1992. A January 31, 1990, working draft of EPA’S proposed new standards indicates that the con- tainment standard is not likely to change significantly. NRC Technical NRC’S regulations set forth procedural and technical requirements appli- Requirements and Criteria cable to DOE, in submitting an application for a repository license, and to NRC, in considering DOE’S application6 Through these regulations, NRC will implement and enforce EPA’S disposal standards. In addition, NRC'S regulations also require that DOE meet a number of performance objec- tives and design criteria, including . NRC standards for radiation protection, l design criteria for the surface and underground facilities of a repository and the waste packages, l a minimum life (300 to 1,000 years) of the waste package to be emplaced in the repository, l a limit on the release rate of radiation from the engineered barriers of the repository, and l a minimum groundwater travel time of 1,000 years from the repository to the accessible environment, determined without consideration of the effects of the waste. Until DOE applies for a repository license, NRC’S role in the repOSit0I-y program is limited to providing regulatory guidance and oversight of DOE’sprogram. On November 21, 1989, the NRC staff briefed the NRC Commissioners on Can EPA’s plans to continue their evaluation of EPA’S standards and on a proposed Containment Standard strategy for implementing the standards through NRC’S repository licens- Ek Effectively ing regulations. The major issue of concern to the NRC staff is whether NRC can implement EPA’S containment standard in a repository licensing Implemented? proceeding without unduly delaying or paralyzing its licensing regula- tory process. The staff noted that NRC had accepted EPA’S standards in October 1985, but had some continuing reservations at that time about how it would implement the standards. NRC'S staff intends to draw on its “NWPApermittedNRCto issueita repositoryregulations(10 C.F.R.part 60) in advanceof EPA’s standardsbut requiredNRCto amendits regulations,if necessary,to ensurethat the regulationsare “not inconsistent”with EPA’sstandards. Page 16 GAO/RCED90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix I Issues tinceruiug Development of Environmental Standarda for Nuclear waste Disposal experience with probabilistic methods of assessing risk related to nuclear power plants, such as application of NRC’Ssafety goals to nuclear plants, to determine if the staff retains confidence that the standard can be implemented. NRC Is Reconsidering The NRCstaff’s concern is that demonstrating compliance with EPA’S EPA’s Containment standard may rest too heavily on the numerical calculations and analy- ses that DOEmust make in projecting the long-term performance of a Standard repository-a process that involves, among other things, predicting the occurrence of highly uncertain events over a lO,OOO-yearperiod. Fur- thermore, the staff believes that the standard does not sufficiently clar- ify how expert technical judgments and other qualitative factors that have traditionally played an important role in NRC’Sregulatory decisions are to be weighed in licensing a nuclear waste repository. NRCbelieves that a strict interpretation of EPA’Scontainment standard could paralyze its repository licensing process. The NRCstaff recognizes that EPAdoes not intend that repository licensing decisions be based solely on numerical estimates of the probability of occurrence of infre- quent events. For example, EPArecognizes that DOEand NRCmay have to make qualitative judgments when necessary to evaluate a proposed repository. In an October 17, 1989, paper prepared for the Commission, the NRCstaff noted, however, that (1) the probabilistic standard is still the governing standard, (2) an acceptable approach to implementing the containment standard has not been clearly established, and (3) a ques- tion still remains as to whether probability estimates for very unlikely events can be derived in any meaningful way. The NRCstaff summarized its concerns in the paper as follows: “Differing views on implementation of the [EPA] standards ultimately derive from different perceptions of the statistical rigor required for estimates of the probabili- ties of potentially disruptive events such as fault movement,volcanic activity, and climate change.A rigorous application of EPA’snumerical standards would require estimates of the probabilities of potentially disruptive events that are derived from a statistical data baseof previous occurrencesof those events at the repository site. Someof the events of interest may be relatively rare comparedto the length of the geologicrecord for the repository site. . . Moreover, somepotential events may not even be evidencedin the geologicalrecord (e.g., human-initiated events). Therefore, a rigorous application of the EPA standards would lead to the conclusion that the standards cannot be implementedin a licensing review.” (Underscoring added.) An NRCofficial who spoke at the November 1989 Commission meeting stated that the best alternative standard to the present containment Page 16 GAO/RCED-99-130 Nuclear Wade Quarterly, Dee. 31,1989 Appendix1 Ii3euef1 Cawerning Development of Ebdronmentd Stendarda for Nuclear we&! Dlepotd standard that NRC staff could identify was a purely qualitative standard. According to the official, an advantage of a qualitative standard is flexi- bility of implementation, but there is also a loss of precision in such a standard. NRC Approaches to NRC'S staff is exploring options on how it can best implement EPA'S Resolving the Containment nuclear waste standards. Specifically, the staff believes that additional clarification and guidance from the Commission and EPA are needed to Standard Issue decide how qualitative technical judgments are to be used by DOE in demonstrating a “reasonable expectation” of compliance with EPA'S con- tainment standard. In its October 1989 paper, the NRC staff said that NRC could (1) reaffirm its original acceptance of the containment standard if EPA clarified areas of concern to NRC or (2) petition EPA to reissue the standard in an altered or non-probabilistic form if NRC decides that the standard cannot be implemented. NRC'S staff believes that either of these two actions may also have to be combined with appropriate amendments to NRC'S regula- tions. Therefore, the NRC staff identified four alternative courses of action: Alternative 1: Maintain the probabilistic format of the EPA standard in conjunction with NRC'S current licensing regulations, with minimal changes to resolve implementation problems and ensure consistency between the regulations. Alternative 2: Make the EPA standard more qualitative, and implement it through NRC'S current licensing regulations. Alternative 3: Maintain a probabilistic format for the EPA standard, but have EPA expand its interpretation of the standard and NRC appropri- ately amend its regulations. Alternative 4: Assume that revised EPA standards will not be in place before a repository licensing proceeding. NRC would use a qualitative cri- terion of “no unreasonable risk to public health and safety” from its existing regulations. In evaluating the four alternatives, the NRC staff recommended that alternative 3 be adopted, and in fact, had already begun pursuing this approach. Under this alternative, the staff would attempt to identify and resolve potential implementation problems with EPA'S containment Page 17 GAO/RCED-BO-130 Nuclear Waste Quarterly, Dec. 31,lBBB 1 , Appendix I Iseues Concerning Development of Environmental Standards for Nuclear Waste Disposal standard and encourage EPA to clarify the standard. This would occur through NRC interaction with EPA'S staff, preferably before EPA issues revised standards to comply with the 1987 court decision. NRC staff also would amend its licensing regulations to resolve, where practicable, any outstanding disagreements between EPA and NRC. The NRC staff believes that it may have to develop and issue two or three rules to accomplish this. One proposed rule would conform NRC'S reposi- tory licensing regulations with EPA'S revised disposal standards. In a sec- ond proposed rule, NRC staff would identify a basis for DOE to make site- specific determinations of “potentially disruptive” processesand events in calculating projected radiation releases. NRC is also considering the possibility of developing a third rule that will provide DOE guidance on acceptable means to implement the standards, such as specification of methods to validate DOE models and computer codes used to support compliance with the standard. According to NRC staff, these actions should help resolve certain controversial issues before a repository licensing proceeding and reduce impediments that may otherwise delay or prevent a licensing decision. NRC staff does not favor alternative 1 because it m ight complicate the licensing process by leaving many issues unresolved until that process begins. For example, the NRC staff said, unless NRC identifies and clari- fies acceptable methods for DOE to estimate the likelihood of potentially disruptive events, it could be virtually impossible to resolve related issues within the 3-year repository licensing period permitted by NWPA. The staff believes that alternative 2 m ight allow more flexibility for implementation of EPA'S containment standard by substituting qualita- tive terms (such as likely, unlikely, etc.) for the numerical expressions of probabilities now contained in the standard. However, the staff did not recommend this approach becausethe lack of a clearly acceptable standard m ight introduce significant uncertainties in interpreting the standard during the licensing process. The NRC staff is not in favor of alternative 4 becauseit presumes that EPA'S revised standards will be available when they are needed. NRC plans to keep abreast of EPA'S plans to reissue the standards as directed by the court, and if necessary, to reevaluate the desirability of exploring this alternative. An advisory committee reporting to NRC on high-level nuclear waste pol- icy and nuclear reactor safety matters, the Advisory Committee on Nuclear Waste (ACNW), did not agree that the NRC staff’s proposed Page 18 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,lBBB Appendix I Iesues Concerning Development of Environmental Standards for Nuclear Waste Disposal approach was adequate to resolve implementation issues with EPA’S con- tainment and other disposal standards. In a December 21, 1989, letter to the Chairman, NRC, ACNW noted that it had continuing concerns.about whether compliance with the EPA standards could be effectively demon- strated for a specific repository site, even though EPA had added the qualification of a “reasonable expectation” of compliance to the stan- dards. It also stated that one alternative that NRC should consider was to object to the EPA'S proposed revisions to the standards because the stan- dards (1) may be unrealistic, (2) are overly stringent and inconsistent compared to those for other health and safety risks, and (3) according to strong evidence, will be wasteful of resources and provide little com- mensurate benefit. It recommended that the NRC staff be more aggres- sive in dealing with EPA to ensure that the EPA standards are scientifically sound, consistent, and readily subject to implementation and interpretation. According to ACNW officials, the NRC Commissioners asked ACNW to provide them with additional information on ACNW’S basis for objection and to recommend a possible solution to the standards- implementation issue. NRC Objected to EPA’s EPA published draft standards for nuclear waste repositories in Decem- ber 1982, and NRC commented on the standards in May 1983. NRC Original Proposed objected to the probabilistic nature of the proposed containment stand- Containment Standard ard. NRC contended that demonstrating compliance with this standard would require a degree of precision in evaluating a real waste disposal system that is not likely to be achievable. It would, NRC said, presumably require the use of numerical risk analysis techniques to identify poten- tial sequences of events or processes leading to releases of radioactive materials, followed by preparation of a numerical probability estimate for each of these sequences. NRC considered the latter step both unwork- able and unnecessary for determining the acceptability of a proposed repository. At that time, NRC did not completely rule out EPA’S probabilistic approach to the containment standard. Rather, NRC recognized that the approach may be useful to the extent that meaningful data are availa- ble, as one of the bases for establishing disposal system performance. NRC suggested that EPA substitute qualitative terms to the proposed con- tainment requirements, emphasizing that expert technical judgment is needed in determining compliance with them. Moreover, NRC stated that there should be a test of “reasonable assurance” rather than of absolute certainty that the containment standard could be met. Page 19 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 . Appendix I Issues Concerning Development of Environmental Standards for Nuclear Waste Disposal EPA incorporated some of the modifications that NRC had suggested into its final containment standard. For example, EPA emphasized that it did not expect unequivocal proof of compliance with the standard because of the substantial uncertainties inherent in making long-term projections of repository performance. Instead, EPA established a test of “reasonable expectation” of compliance based upon practically obtainable informa- tion and analysis. Based on EPA'S changes to its proposed containment standard, NRC with- drew its objections. In an October 1985 paper, the staff informed the Commission that, although implementing EPA'S probabilistic standard would pose a significant challenge to NRC, the final standard neverthe- less could be implemented. The NRC staff also stated that it planned to conduct technical analyses to determine whether any changes were nec- essary to the repository performance objectives in NRC'S regulations to ensure consistency of its regulations with EPA'S standards. The NRC Com- missioners accepted the staff’s recommendations. The Advisory Committee on Reactor Safeguards (ACRS), the predecessor NRC advisory group to the ACNW, did not agree with NRC'S staff. The ACRS was highly critical of EPA'S final standards and, in particular, the con- tainment standard. For example, in an October 1985 letter to the NRC Chairman, ACRS described the probabilistic containment standard as “unreasonably restrictive” and containing “serious deficiencies.” ACRS also stated that the overly restrictive nature of the probabilistic stand- ard would introduce unnecessary licensing obstacles with only minimal benefit to the public health and safety. Finally, ACRS stated that because of the combination of the low level of allowable risk and the probabilis- tic nature of the containment standard, it had no confidence that NRC would succeed in making a formal determination that a proposed DOE repository complies with the standard. The NRC Commissioners reaffirmed their support of EPA'S standards, but concluded that NRC should accelerate its efforts to develop analytical methods to determine whether a proposed repository would comply with EPA'S standards. Moreover, it said that ACRS' concerns should be addressed by (1) clarifying ambiguities in the application of the proba- bilistic standard and (2) conforming NRC'S repository performance objec- tives to EPA'S standards. In June 1986, NRC subsequently published a proposed rule to conform its regulations to the EPA standards. However, before NRC could complete the rulemaking, the 1987 court decision to withdraw and remand the standards to EPA for further work was issued, and NRC curtailed its initiatives to conform its rules to EPA'S standards. Page 20 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix I Iseues Concerning Development of Environmental Standards for Nuclear Waste Disposal Contrast Between EPA’s As discussed above, one concern of the NRC staff is that, although EPA'S Containment Standard and containment standard only requires “reasonable expectation” of compli- ante, the numerical standard is the governing standard. This approach NRC’s Safety Goals is in sharp contrast to NRC'S safety goals for nuclear power plants. Those goals are stated in qualitative terms and supported by probabilistic objectives. Furthermore, in adopting the safety goals, NRC made it clear that, because of the limitations of risk assessment technology and related data, the probabilistic objectives were not to be substituted for existing safety regulations. In response to recommendations of the President’s Commission on the Accident at Three Mile Island, between 1981 and 1986 NRC developed a policy statement on safety goals for the operations of nuclear power plants. The objective of the policy statement was to establish goals that broadly define an acceptable level of radiological risk to the public as a result of the operation of nuclear power plants during both normal oper- ations and accidents. In the policy statement, NRC adopted two qualita- tive safety goals as follows: . Individual members of the public should be provided a level of protec- tion from the consequences of nuclear power plant operation such that individuals bear no significant additional risk to life and health. . Societal risks to life and health from nuclear power plant operation should be comparable to or less than the risks of generating electricity by viable competing technologies and should not be a significant addi- tion to other societal risks. In addition, NRC established two quantitative (probabilistic) objectives that were to be used in determining achievement of the safety goals. The objectives are as follows: l The risk to an average individual in the vicinity of a nuclear power plant of prompt fatalities that might result from reactor accidents should not exceed one-tenth of 1 percent of the sum of prompt fatality risks resulting from other accidents to which members of the U.S. popu- lation are generally exposed. . The risk to the population, in the area near a nuclear power plant, of cancer fatalities that might result from nuclear power plant operation should not exceed one-tenth of 1 percent of the sum of cancer fatality risks resulting from all other causes. According to NRC'S policy statement, progress in developing the tech- niques for quantitatively estimating risks made it feasible to begin to Page 21 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendi% I lssuea Concernlug Development of Enviroumental Stamlads for Nuclear waste Disposal use quantitative safety objectives for limited purposes. However, because of the sizable uncertainties present in the methods and the gaps in the data base-essential elements needed to gauge whether the objec- tives have been met-the quantitative objectives should be viewed as aiming points or numerical benchmarks of performance, In particular, because of the present limitations in the state of the art of quantita- tively estimating risks, the quantitative objectives are not a substitute for existing regulations. Finally, NRC specified in the policy statement that the safety goals were not meant to be used as a sole basis for licensing decisions but could be considered as one factor in a licensing decision. This position was consis- tent with our conclusion in a June 1985 report on NRC’S use of probabil- istic risk assessment technology in regulating commercial nuclear activities.” In that report, we cautioned that NRC should not use probabil- istic risk assessments as the sole or primary basis for regulatory deci- sions; rather, NRC should use this technology to supplement its more traditional analytical and engineering methods. Thus, in developing safety goals for nuclear power plant operations, NRC made quantitative estimates of risks to both individuals and society subordinate to qualitative statements of its safety goals. In contrast, EPA’S containment standard sets out a quantitative standard and then qualifies the standard to recognize the inherent limitations and uncer- tainties in establishing compliance with the standard. %-obabilistic Risk Assessment:An EmergingAid To NuclearPowerPlant Safety Regulation(GAO/ 86-l 1, June 19,1986). Page 22 GAO/RCED-90-130 Nucleas Waste Quarterly, Dec. 31,1989 Appendix II ChallengesDOE Facesin ComplyingWith EPA’s ContainmentStandard DOE has a formidable task in successfully determining if a repository at Yucca Mountain can safely isolate waste from the environment for at least 10,000 years. Its site characterization plan lays out an approach that recognizes the considerable uncertainties in achieving this objec- tive. Also, DOE recently extended its repository schedule 7 years because, in part, of the scientific challenge of adequately investigating the site. DOE now expects to begin investigating the site in about 1 year. If the results are favorable and the site is selected, DOE plans to apply for an NRC license to construct a repository in about 2001. With a 3-year licensing period followed by repository construction, DOE projects that it could begin waste disposal operations by 2010. NRC, its advisory group on nuclear waste, and utility representatives are concerned that uncertainties associated with data to be collected and the analysis of the data using computer models simulating site conditions may be great enough to prevent DOE from convincingly demonstrating compliance with the containment standard. Accordingly, they are con- cerned that compliance with the standard could be an issue subject to protracted litigation in a future licensing proceeding. In this regard, EPA and NRC believe that DOE'S pending assessment of the WIPP facility’s com- pliance with EPA'S disposal standards may provide valuable information for implementing the standards at Yucca Mountain. In 1985, after EPA had modified its draft containment standard to recog- DOE’s Plans to Comply nize qualitative considerations, DOE concluded that EPA'S standards were With EPA’s flexible enough to be implemented in its repository program. The Containment Standard agency’s December 1988 site characterization plan describes its approach for implementing the standards in investigating the Yucca Mountain site and in developing a repository design.1 DOE will address the EPA standards, particularly the probabilistic containment standard, by conducting performance assessments of the natural features and man-made components of the repositoryS2 According to DOE's plan, performance assessments are to be based on various conceptual models used to describe the characteristics of the site and on knowledge of the processes and events that could occur at the ‘DOE recognizedin its site characterizationplan that the EPA standardswere vacatedby the 1987 court decision.However,until suchtime as changesto the EPA standardsare implemented,DOE plans to collect data on the YuccaMountainsite and repositorybasedon EPA’s1986standards. 2WE defies performanceassessmentaa any analysisthat predictsthe behaviorof a systemor com- ponentof a systemunder a given set of constantor transient conditions. Page 23 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 . Appendix II Challenges DOE Faces ln Complying With EPA’s Containment Standard site acquired through site investigations. The latter includes infre- quently occurring events such as volcanic activity, earthquakes, flood- ing, and climate changes. Using these inputs, DOE will develop computational models of site and repository performance. DOE plans to conduct its performance assessment of Yucca Mountain in the following sequence: . Identify all significant anticipated and unanticipated processes and events that may affect the geologic repository. . Group related processes and events into various classes or scenarios for the release of radiation. . Screen the scenario classes in terms of their probability of occurrence and the potential releases of radioactivity associated with them. . Develop appropriate computational models for evaluation of the scena- rio classes. l Evaluate the effect of the related processes and events on the release of radiation into the accessible environment. . Calculate an overall probability distribution for the cumulative release of radiation to the accessible environment, taking into account the uncertainties in the parameters of the computational models and the probability of occurrence for each scenario class. DOE acknowledges that to demonstrate overall waste system (site, repos- itory, and waste package) performance, it will place heavy reliance on the conceptual models of the repository site, physical systems, and the hypotheses on which they are based. If the models can be confirmed by tests conducted during site characterization, then its testing strategy should be sufficient, according to DOE, to resolve repository performance and design issues, However, DOE recognizes that some of the conceptual models and its associated testing strategies may need to be modified as site characterization progresses. Uncertainties Related to DOE recognizes that each conceptual model of one or more repository systems has some degree of uncertainty associated with it, and this Yucca Mountain uncertainty is reflected in the fact that DOE must also consider alterna- tive conceptual models. In other words, more than one set of hypotheses may be consistent with the data that DOE collects. According to DOE offi- cials, it is evaluating many alternative conceptual models as part of its * site characterization program. DOE’S challenge is to identify those alter- native models that are potentially descriptive of the site and to ensure Page 24 GAO/RCED-99-130 Nuclear Waste Quarterly, Dec. 31,1989 Appetdx II Challengen DOE Faces in Complying With EPA’s Containment Standard that these models are given appropriate consideration in its perform- ance assessments. Moreover, DOE has noted that expert judgment will also play an important part in,developing performance assessments and in selecting scenarios and scenario classes necessary to calculate the overall probabilities of projected cumulative radiation releases. During site characterization, DOE intends to evaluate and reduce the uncertainty in its estimates of repository performance that are sup- ported through predictive models. DOE’s goal is to ensure that its model- ing efforts result in a level of uncertainty that is acceptable to NRC and that regulatory requirements will be satisfied with a reasonable degree of assurance. In addition, DOE plans to validate its performance assessment models and the underlying conceptual models on which they are based. The val- idation process will demonstrate that mathematical representations of repository performance adequately replicate the repository’s actual per- formance. DOE also plans to validate the quality and appropriateness of its data, including the assumptions it uses to build predictive models. Overall, DOE believes that outside peer reviews may be necessary to assess the competence of its scientific investigations and to judge the uses made of results. Utility Group’s Comments The Edison Electric Institute and the Utility Nuclear Waste and Trans- on Uncertainties portation Program jointly commented on DOE’S site characterization plan.3 The group is concerned that DOE’S final plans do not reflect a full appreciation of the difficulty in reducing site-related uncertainties. In addition, the group believes that DOE’S processes of gathering, analyzing, interpreting, and summarizing its data on Yucca Mountain involve con- siderable judgments which may be challenged during a licensing proceeding. According to the utility group, difficulties with modeling are likely because heavy reliance must be placed on the judgments of experts to interpret site data and predict site conditions over the next 10,000 years, and there is likely to be disagreement on these interpretations. Also, challenges to expert judgments can be difficult to resolve during licensing. The group said DOE should anticipate and acknowledge the 3TheEdisonElectric Institute is the associationof the nation’sinvestor-ownedelectricalcompanies. The Utility NuclearWasteand TransportationProgramis an associationof electric utilities that moni- tors the implementationof federal statutesand regulationsconcerningnuclearwastemanagement. Page 26 GAO/RCED-90-120 Nuclear Waste Quarterly, Dec. 31,1889 Appendix II Challenges DOE Facea in Complying With Ji?PA’r Containment Stadard problems associated with making and defending modeling-related judg ments that are critical to site evaluation and repository licensing. The group also noted that although the site characterization program is extensive, DOE will, quite appropriately, sample only a small fraction of the site’s volume. The resulting database will be used primarily by experts in making judgments, such as predictions about future volcanic activity, Moreover, because of the site’s complexity, expert predictions will have wide ranges of uncertainty. According to the group, when uncertainties are combined in models assessing the performance of the site and repository, the assessment results will also be uncertain. Because the group believes that resolving issues related to the site’s suit- ability and performance will be more difficult than implied in DOE'S plan, it urged DOE to develop and describe strategic plans for coping with these issues. NRC Comments on NRC has been actively monitoring the progress of DOE's site characteriza- Uncertainty and EPA’s tion program, including its efforts to address EPA'S nuclear waste stan- dards. Comments by NRC'S staff in its October 1989 staff paper indicate Containment Standard that DOE'S plans for site characterization appear to correspond well with the staff’s interpretation of what the standards require. However, the staff is particularly concerned that DOE emphasize the scientific work needed to support the required probabilistic analyses rather than the comparison of the analyses’ results with the release limits specified in EPA'S containment standard. NRC'S staff believes that meaningful, though not statistically rigorous, probability estimates can be developed and reasonably defended for repository sites that are not complex or unusually geologically active. In fact, the staff believes that the required probability estimates will help determine how well a site is understood and, therefore, how much confi- dence can be placed in its future performance as part of a repository. However, the staff added that it is too early to tell whether meaningful probability estimates can be developed for Yucca Mountain. According to the NRC staff’s October 1989 paper, this issue is to be resolved as early as practicable during site characterization. For example, in review- ing and commenting on DOE'S site characterization plan, NRC staff noted that DOE should assign high priority to conducting investigations to determine whether the site is subject to unacceptably high chances of disruption due to occurrences of volcanic activity, faulting, or seismic movements. Page 26 GAO/RCED-B&130 Nuclear Waste f&uuterly, Dec. 31,1989 . Appendix II Challenger DOE Facelr in Complying Wlth EPA’s Containment Standard For several years, advisory groups to NRC have raised concerns about DOE'S site characterization program and compliance with the EPA stan- dards. For example, in July 1989 ACNW advised the NRC Chairman that DOE was not giving sufficient emphasis to the limitations and uncertain- ties in its databases concerning preliminary site characterization activi- ties at Yucca Mountain. The Committee said that uncertainties and limitations in DOE'S data will be the center of most repository conten- tions and that planning for the management of these uncertainties and limitations by DOE is essential. Finally, the committee stated that DOE may have considerable difficulty in calculating an overall probability distribution necessary for demonstrating compliance with EPA'S contain- ment standard. According to ACNW, this problem could represent a dis- qualifying feature for the proposed repository. NRC and EPA are seeking ways in which they can resolve present and WIPP May Provide future implementation issues associated with the latter agency’s nuclear Valuable Insights to waste standards. The specific issue is whether there is adequate confi- Implementing dence that the standards-particularly the probabilistic containment requirements-can be implemented in an NRC licensing proceeding for a Containment Standard repository at Yucca Mountain or elsewhere. One approach that both agencies have suggested to address this issue is to look at the experience being gained through other programs for radioactive waste storage in a geologic environment. In particular, the agencies identified DOE'S WIPP repository near Carlsbad, New Mexico, as a possible precedent for deter- mining how much confidence can be placed in the present or revised EPA standards. The WIPP facility is the culmination of many years of effort to find a site for permanent disposal of transuranic wastes generated as a by-product of the federal government’s defense-nuclear activities. The WIPP project was initiated in 1981 when DOE decided to proceed with the development of a mined geologic repository to store such wastes. To date, DOE has spent about $800 million to complete WIPP site characterization, con- struction, and preoperational activities. Unlike the principal source of nuclear waste to be emplaced in Yucca Mountain-spent (used) nuclear reactor fuel-transuranic waste forms typically contain smaller amounts of radioactivity. Yet, because this waste contains long-lived and hazardous radioactive elements, such as plutonium, it warrants isolation from the environment. Accordingly, WIPP, like a potential repository at Yucca Mountain, must comply with EPA'S disposal standards, An important distinction for the WIPP facility, Page 27 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix II . Challenges DOE Faces in Complying With EPA’s Containment Standard however, is that it is exempt from NRC regulation. DOE itself makes the determination of whether or not the facility meets EPA'S standards. DOE will conduct a computer-simulated performance assessment of WIPP, similar to that of Yucca Mountain, to determine if the facility complies with EPA'S standards. Specifically, using assumptions on the total inven- tory of various elements to be disposed of in WIPP and computerized models, DOE will identify, categorize, and analyze significant processes and events that could affect the repository’s performance; will estimate the cumulative releases of radiation to the accessible environment and potential doses to individuals; and will compare the predicted release rates and doses to release rates and doses contained in the standards.4 DOE designated the first 5 years of WIPP operation as a research and development phase for the purpose of demonstrating the safe disposal of transuranic waste. According to the agency’s latest estimate, this phase is expected to begin as early as July 1990, and the performance assessment is expected to be completed within 4 years. Our recent report on WIPP provides additional details on the status of the facility, DOE’S plans for the testing phase, and potential problems that DOE must deal with in demonstrating compliance with EPA'S standards.” EPA and NRC believe that DOE'S preparation of the WIPP performance assessment may provide valuable insights on how readily EPA'S stan- dards can be implemented in a licensing proceeding. Both agencies share a concern that if DOE’S experience indicates that EPA'S standards appear unworkable, the standards should be clarified or modified to allow NRC to make a reasoned licensing decision on a DOE application to construct a repository. EPA has stated its intention to reexamine its disposal standards and issue alternative standards if necessary. Moreover, EPA has recognized that WIPP may prove to be useful in assessing the feasibility of implementing the current environmental standards. In its comments on a draft supple- mental environmental impact statement for WIPP, EPA urged that DOE publish WIPP performance assessments as an additional supplement to the environmental impact statement, or a similar document, for public 4Accordingto DOE,it will establishWIPP’scompliancewith EPA’sgroundwaterprotectionstandard by demonstratingthat there is no specialsourceof groundwater,as definedin EPA’sdisposalstan- dards,in the vicinity of the facility. “Nuclear Waste:StorageIssuesat DOE’sWasteIsolationPilot Plant in New Mexico(GAO/ RCED-So-1, Page 28 GAO/RCED-90-130 Nuclear Waste Quarterly, Dec. 31,1989 . Appendix II Challenges DOE Faces in Complying With EPA’s Contaiument Standard review and comment. According to EPA, this should be done after the 5- year test phase at WIPP but before DOE begins waste disposal operations at the facility. In its October 1989 staff paper, NRC'S staff also recognized that DOE'S application of EPA'S standards to WIPP could help answer questions about implementing the standards, NRC noted that a demonstration that a real repository can achieve the risk levels of EPA'S containment standard has not been made. NRC'S staff believes that it should review the perform- ance assessments for WIPP as they are released for public comment because the assessments could provide significant insights into the development of performance assessment capabilities at Yucca Mountain. Page 29 GAO/RCED90-130 Nuclear Waste Quarterly, Dec. 31,1989 Appendix III . Major Contributors to This Report Judy A. England-Joseph, Associate Director Resources, Dwayne E. Weigel, Assistant Director Community, and Victor J. Sgobba, Evaluator-in-Charge Richard A. Renzi, Advisor Economic Shirley Christensen, Writer-Editor Development Division, Washington, D.C. (801900) Page 30 GAO/RCED90-130 Nuclear Waste Quarterly, Dec. 31,1989 -. --
Nuclear Waste: Quarterly Report as of December 31, 1989
Published by the Government Accountability Office on 1990-04-30.
Below is a raw (and likely hideous) rendition of the original report. (PDF)