The Symposium

REACTIONS TO "RETHINKING HIGH-LEVEL RADIOACTIVE WASTE DISPOSAL"

"Rethinking High-Level Radioactive Waste Disposal" is reprinted in Appendix A. In general, the report was commended for bringing vital and contended issues to the forefront of debate. Many at the symposium agreed with the report's flexibility recommendations and encouraged increasing the site specificity of the Standard. Representatives of environmental groups, EPA, and the State of Nevada argued that the Standard was not overly stringent, inflexible, or unworkable. DOE pointed out that the program is now much better run than it was at the time of the workshop from which the report was developed. There was strong opinion at the symposium on both sides of the question of the validity of probabilistic release criteria. Several participants lauded the call for increased and more substantive public participation in the development of the Standard and in the licensing process, supporting the need for informal working relationships in addition to formal advisory functions.

One participant pointed out that, although a successful program demands accord on a set of licensing regulations that are rational, reasonable, and firmly grounded in science, the issue at hand, at least for the present, is not licensing. WIPP, not being subject to USNRC licensing authority, is not yet able to start an experimental program due to a delay in land transfer from the U.S. Department of the Interior to DOE. Yucca Mountain is far from a license application as DOE commences investigation of the geology of the mountain. At this point, the Yucca Mountain Project faces many stumbling blocks before it can tackle the intricacies of the USNRC licensing requirements.



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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management The Symposium REACTIONS TO "RETHINKING HIGH-LEVEL RADIOACTIVE WASTE DISPOSAL" "Rethinking High-Level Radioactive Waste Disposal" is reprinted in Appendix A. In general, the report was commended for bringing vital and contended issues to the forefront of debate. Many at the symposium agreed with the report's flexibility recommendations and encouraged increasing the site specificity of the Standard. Representatives of environmental groups, EPA, and the State of Nevada argued that the Standard was not overly stringent, inflexible, or unworkable. DOE pointed out that the program is now much better run than it was at the time of the workshop from which the report was developed. There was strong opinion at the symposium on both sides of the question of the validity of probabilistic release criteria. Several participants lauded the call for increased and more substantive public participation in the development of the Standard and in the licensing process, supporting the need for informal working relationships in addition to formal advisory functions. One participant pointed out that, although a successful program demands accord on a set of licensing regulations that are rational, reasonable, and firmly grounded in science, the issue at hand, at least for the present, is not licensing. WIPP, not being subject to USNRC licensing authority, is not yet able to start an experimental program due to a delay in land transfer from the U.S. Department of the Interior to DOE. Yucca Mountain is far from a license application as DOE commences investigation of the geology of the mountain. At this point, the Yucca Mountain Project faces many stumbling blocks before it can tackle the intricacies of the USNRC licensing requirements.

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management 40 CFR PART 191 Much of the debate at the symposium focused on technical criticisms of the Standard. James Curtiss, a USNRC Commissioner, made the point that the Standard was based on what was technically feasible rather than on an overall health and safety goal. Lawrence Ramspott, of Lawrence Livermore National Laboratory, said that the rule was written in 1985, based on 1970s technology. He suggested that if the EPA is to retain a standard based on what is feasible, revisions should be made to take into account newer technology and newly available data. Ramspott noted several changes since the 1970s: at that time there was a lack of data on actual radioactive waste, effects of water chemistry, and unsaturated sites. Since then, tests have been made on spent fuel and glass containing radioactive waste, and much work has been done with groundwater from sites and rock-equilibrated groundwater in the presence of container materials under a variety of conditions, including both saturated and unsaturated zones. In addition, much work has been done with container materials, such as copper, which greatly diminish the degree to which a repository must depend on geologic behavior. Other technical criticisms raised at the symposium were: The Standard should be stated in terms of annual limits on the radiation dose to individuals rather than as release limits over broad time periods. The containment requirements should be directed toward the protection of individuals rather than populations. The Standard poses requirements in terms of numeric probabilities, an approach that has never been used previously in a federal standard and that the responsible agencies have no experience in implementing. The required evaluation of the human intrusion scenario is inadequate because it relies on unsupportable societal predictions 10,000 years in the future, thus suggesting that accurate predictions can be made over the far term, and rendering geologically different sites virtually equivalent in risk. The Standard is unnecessarily stringent compared with similar standards for disposal of hazardous chemical waste, especially considering the level of unavoidable background radiation that exists, both naturally occurring and man-made. An opposing view of the Standard's stringency was also expressed; two speakers thought the Standard was unnecessarily lenient compared with similar standards for disposal of hazardous waste. In focusing on protecting future generations the Standard pays insufficient attention to current worker exposure. The Standard provides flexibility only at the discretion of EPA administrators. Such flexibility should be built into the Standard so

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management that DOE can design a facility to take advantage of the range of possibilities for demonstrating compliance. Where the Standard calls for "reasonable expectation" of meeting limits, "reasonable" should be defined, so that DOE and contractors know how to measure it and to determine when it has been achieved. The Standard was also criticized for its lack of attention to cost-effectiveness. It states in several places that compliance should not impose an unreasonably difficult or expensive burden on those seeking to comply. However, speakers noted, when the EPA said that site characterization was not unduly expensive, the agency had not had any experience with conducting such a characterization. It is now known that straightforward characterization, even without extensive litigation, is complicated and resource consuming. For example, most available data in the early 1980s assumed congruent dissolution; it has now been shown that dissolution in groundwater is noncongruent due to differences in nuclide solubility. Determining the extent to which dissolution is not congruent will be time consuming and costly. Many speakers stressed the importance of taking a new look at the expense of implementing 40 CFR Part 191 and how it relates to the benefits. They perceive the Standard as demanding protection that goes beyond that required for public safety, incurring exponentially greater costs for each additional increment of protection. This inattention to cost stems from the fact that what could be achieved with 1970s technology was far less costly than what could be achieved in 1990, in part because extremely small amounts of radiation can now be detected. The desire to shield the public and the environment from even the lowest levels of radiation may lead to HLRW disposal costs that are out of proportion to what is spent to curtail greater environmental hazards from other hazardous wastes. David Pentz, an environmental and geotechnical consultant, asserted that it is questionable whether the stringency of the Standard is indeed furthering the public safety to any measurable degree. Pentz and Thomas Cotton, an environmental consultant, noted that when EPA justified their level of stringency based on what was technically feasible at the time, they reached the conclusion that the cost of compliance would not be burdensome. However, some of the assumptions on which they based that conclusion have changed significantly; Pentz and Cotton suggested that it might be useful for EPA to reexamine their analysis and conclusions. PROBABILISTIC RELEASE STANDARDS VS. INDIVIDUAL DOSE LIMITS Much opposition was expressed to EPA's selection of probabilistic re-

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management lease limits for protection of the public over the extended time frame of 10,000 years following waste disposal. James Mercer, a hydrogeologist, voiced doubt about the scientific basis for predicting transport of radionuclides for such a long period of time. He noted that projections for only a 10-to 20-year time frame are difficult. This view was voiced also by symposium participant David Okrent, a reactor safety physicist and consultant to the Advisory Committee on Nuclear Waste, who served on a subcommittee of the Science Advisory Board (SAB, EPA's advisory Board) that reviewed the Standard. He criticized the EPA's use of that review to support the idea that 10,000-year projections can be made with reasonable confidence. In Okrent's opinion, the probabilistic group that worked on the report had "strong questions about one's ability to estimate risk out to 10,000 years." He said that the "reasonable confidence" statement used by the EPA to back the Standard was an unfortunate choice of language that made its way into the Executive Summary (Appendix E) of the SAB report. At the symposium, several speakers pointed out that the International Commission on Radiological Protection and other groups, both national and international, had concluded that an annual dose limit to the individual was the best criterion by which to judge the long-term acceptability of solid waste disposal. A USNRC staff representative discussed the possibility of a deterministic basis for licensing geologic repositories that closely parallels common precedents for individual risk-based standards and regulations. An example would be a quantitative standard, such as the 4 millirem/year individual dose specified in the Drinking Water Standard. Such an approach has been found generally to avoid the potential for large individual doses possible under a population-based standard, to ease interpretation and determination of compliance, and thus to be less likely to lead to controversy. Another reason given to support annual dose limits to individuals is the difficulty of determining the relative merits of any specific site by using the EPA probabilistic release limits. Various groups found insufficient EPA's explanation of how the generic standards were derived from the upperbound population health risk goal; they requested that further clarification of the limits be provided and, if probabilistic release limits are to be retained, that these limits become secondary to a primary annual risk or dose-limit standard. The Standard does, it was pointed out, recognize the value of dose limits in requiring that engineered controls be able to prevent significant individual doses in the near term (i.e., for the first 1,000 years after disposal). The Standard also provides annual limits on individual dose and on average groundwater contamination from undisturbed performance in that initial period. Demonstrating compliance with individual dose limitations beyond 1,000 years was considered to be very difficult, due to the complexities involved in estimating exposures.

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management The EPA and others consider probabilistic release limits over the long term to be preferable to annual dose/risk limits for several reasons. First, the performance of a repository must be judged over very long periods of time, during which determination of compliance by the physical processes of measurement or inspection cannot be assured. The EPA views probabilistic limits on total releases integrated over time as providing a meaningful, if not absolute, standard for evaluation that more readily accommodates consideration of disturbance of a repository at both the population and the individual level. If annual dose limits for individuals were to be used, contrary to present practice, they would have to be evaluated on an incremental, multigenerational basis, taking into account the probability of potential releases. Second, EPA points out that probabilistic limits on total releases over time from a repository present a quantitative standard against which the criterion of success may be more readily measured. Use of individual annual dose limits over long time periods would complicate the analytical task, again probabilistically, by requiring predictions of environmental events, human behavior, and exposure pathways to people on a year-by-year, multigenerational basis. The potential for nonresolution of issues and for adversarial situations would thereby, according to the EPA, be enhanced. Curtiss expressed his concern about the continuing and contentious debate over the feasibility of implementing the probabilistic portion of the Standard, and argued that a clear and unambiguous approach to its implementation in a licensing review has not been identified. Support for probabilistic limits came from Robert Loux, representing the State of Nevada, who felt that if WIPP and Yucca Mountain cannot meet the licensing criteria, new sites should be chosen. He said that before the Standard is rejected as unworkable, it should be tried on a less complicated site than Yucca Mountain. Loux believes that many in the HLRW community wish to alter the Standard in order to render the WIPP and Yucca Mountain sites viable. Robert Neill, of the New Mexico Environmental Evaluation Group, noted that the very concept of geologic isolation presumes the ability to predict long-term geological integrity. Robert Shaw, of the Electric Power Research Institute, recommended a compromise, retaining the probabilistic approach as an acceptable option for anticipated events. For unanticipated events, such as human intrusion, he recommended a separate release limit on an event-by-event basis for those processes sufficiently credible to warrant consideration. STRINGENCY OF THE STANDARD General concern was expressed at the symposium that the risks associated with disposal under the Standard, though acceptably small, might be

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management unnecessarily small, especially when compared to similar limits for the disposal of other hazardous chemical wastes and compared to the much higher level of unavoidable, natural and man-made background radiation. For example, while the Standard would permit a HLRW repository to cause no more than an average one cancer death every 10 years, EPA estimates that existing concentrations of naturally occurring radon inside houses in the United States are causing one cancer death every 18 to 75 minutes. Shaw observed that EPA's rationale for an acceptable level of risk from radioactive waste was based on the waste risk being a certain fraction of the fuel cycle risk and therefore being lower than or equal to the total risk from nuclear reactor operations. He contended that there is no scientific basis for judging the EPA's fraction to be a reasonable risk relative to other accepted societal risks. He views the EPA rationale as a judgment based on a nonscientific response to the idea of radiation and would replace it with a rationale based on well-supported societal safety goals. The stringency that draws criticism is found in the quantitative levels set for radionuclide release and containment, and also in the high probabilistic confidence levels that are required by 40 CFR Part 191. The confidence levels of the containment requirements, 90 percent and 99.9 percent, are unprecedented in their high conservatism. According to Wendell Weart, of Sandia National Laboratories, the orders of magnitude of uncertainty introduced into the CCDFs by the probabilistic assumptions, together with the uncertainty inherent in modeling releases that result from human intrusion, undermine the ability of any site to meet the Standard's assurance requirements. DOE and others worried that the existing Standard might be so restrictive that it slows, or precludes, the characterization of any repository site. Although John Bartlett, Director of DOE's Office of Civilian Radioactive Waste Management, warned that the stringency of the Standard is costing the HLRW program a lot of time, money, and public confidence, he insisted that DOE is not complaining about the Standard; DOE's role is to comply with the Standard (and the Regulation) and develop methods for evaluating compliance. A question was posed as to the degree to which the release limits and associated residual risks might be raised and still provide an acceptable level of protection. On the other hand, some speakers suggested that the Standard is not too stringent with respect to acceptable levels of risk, and might even require tightening, in view of both increased estimates of health effects from low doses of radiation and improvements in waste containment theory and technology. EPA explained at the symposium that public acceptance is an important factor in setting regulatory limits, and the agency is confident that the requirements are perceived by most people as adequately protecting human

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management health and the environment. EPA and Nevada officials asserted that the Standard would be within reach if the repository were properly sited. Dan Reicher, of the Natural Resources Defense Council, suggested that if the existing licensing approach is abandoned the process might have to be started over with a new set of potential repository sites. He said that otherwise the public would perceive any effort to alter the regulatory process as an attempt to protect the current potential sites — WIPP and Yucca Mountain — from possible failure under the present Standard. Others held the view that compliance with the current Standard would achieve a level of protection greatly exceeding that needed to protect human health and the environment. However, according to some participants, if the EPA were to adjust the Standard now, regardless of the rationale, the changes would seem to be politically, rather than scientifically, based. It might be thought that the requirements were being changed in order to ensure that the prospective Yucca Mountain repository would be licensable. Richard Guimond, the EPA representative, warned that if the EPA relaxed the Standard, public skepticism would grow and the program would face even greater problems. Cotton, however, submitted that it might be better to fix the Standard now, rather than later, when and if significant problems with compliance have developed. A later adjustment in the face of problems might cause even greater difficulties with public perceptions. He also suggested that, since the Standard and the Regulation were conceived at a time when many sites were being considered, and Congress has since changed the mission to one of approving or disapproving one candidate, it would be appropriate to reconsider the agency rules in view of the new mission. FLEXIBILITY Part of the problem of stringency for many of the participants lay in the specificity of the Regulation. It was argued by many that, without relaxing the requirements for the overall performance of the repository, design and planning could be made easier by restructuring the requirements of the Regulation. Some believed that if the USNRC were to rely only on the system performance requirement adopted from 40 CFR Part 191, rather than on the current subsystem requirements for a repository, the systems designers would have more freedom to engineer into the containers and waste forms a level of safety that could offset flaws or uncertainties in the geology of a site. In 10 CFR Part 60, the USNRC allows for flexibility (by means of case-by-case exemptions) in implementation, but all the flexibility is left to the discretion of the USNRC. Speakers argued that the flexibility should be defined in the Regulation, in order to give the licensee the ability to design according to site characteristics, with the knowledge that approval of speci-

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management fications is not subject to the changing politics and regulatory conservatism of the regulating agency. Curtiss pointed out the difficulty of relying on the exemption procedure to address issues late in the process. The same argument was made for building flexibility into 40 CFR Part 191. Section 191.17 of the Standard permits alternative provisions, but any alternative must undergo extensive public consideration. Reicher noted that an important drawback of iterative, flexible standards is that all too often, where rigorous compliance standards and detailed licensing requirements are not imposed on large, costly projects, corners are more likely to be cut in the name of program objectives or schedules. Frank Parker, then Chairman of the BRWM, maintained that sound, definitive standards need not preclude flexibility in the method by which a repository meets compliance. THE LACK OF A TECHNICAL CONNECTION BETWEEN THE STANDARD AND THE REGULATION Regulations are generally designed to assure achievement of a corresponding goal, such as health protection or worker safety. Some symposium participants repeatedly criticized the fact that compliance with the Regulation does not necessarily achieve compliance with the Standard. At the symposium, Curtiss emphasized the significance of the discrepancy between the EPA release limits and the USNRC subsystem criteria specifying geological and container limits. The USNRC's methodology is deterministic, specifying quantitative criteria for multiple barrier performance, while the EPA's Standard is probabilistic, based on CCDFs for containment limits. Because of this discrepancy, those seeking repository licenses are currently faced with complying with disparate requirements simultaneously. The linkage between the Regulation and the Standard it is intended to implement was termed the ''technical nexus'' by Curtiss. He emphasized the need for an unambiguous technical nexus because responsibility for implementing the HLRW program is divided between the EPA, which sets generally applicable standards, and the USNRC, which establishes the implementing regulations. As yet, CurTiss noted, the USNRC has been unable to identify a clear and unambiguous approach to implementing the Standard in licensing review. He believes that the lack of a nexus stems in part from the different approaches required by deterministic and probabilistic methods. The fact that the Regulation was promulgated while the EPA was still drafting the Standard is also a factor. (EPA's final rule states that the Regulation incorporates the limits that the EPA was promulgating in the Standard and that the Regulation was designed in concert with EPA's ongoing development of the Standard. In addition, the EPA stated in its promul-

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management gation of 40 CFR Part 191 that it expected the USNRC to revise 10 CFR Part 60 to bring it into full consistency with the Standard.) A resolution of these disparate approaches could be effected by either or both agencies. Curtiss suggested that the USNRC could restructure the subsystem performance criteria of the Regulation, during resolution of the court remand, to establish such a nexus. But first the EPA must document the basis for the Standard, in accordance with the remand. The EPA could go further, in Curtiss's opinion, by reevaluating and revising the Standard to establish requirements that are realistic, technically justified, and defensible with respect to possible litigation. This task would best be accomplished now when the involved agencies can make technical adjustments reflecting clearer objectives and improved technical knowledge. If done later, the necessary modifications, relaxations, or stringencies may be interpreted incorrectly as excessive weakening or strengthening of public safety requirements. At the symposium both the EPA and the USNRC expressed a willingness to communicate about working toward the nexus, but the EPA did not want to waver from its reliance on the probabilistic Standard, and the USNRC is unlikely to abandon its deterministic subsystem requirements. Negotiated rulemaking was mentioned by several speakers as a process that might work well to see the USNRC and the EPA through some evolutionary change, provided that all parties believed they could achieve an outcome better than the status quo. As a result of the exchange at the symposium, the feasibility of negotiated rulemaking was examined by RESOLVE, a dispute resolution program of the Conservation Foundation. RESOLVE conducted preliminary interviews with EPA, USNRC, DOE, the Edison Electric Institute, the Electric Power Research Institute, and the Natural Resources Defense Council. Although EPA was eager to enter into negotiated rulemaking, RESOLVE could not recommend that they take that action. Reasons that various of these entities rejected the idea of negotiated rulemaking include: too many issues under dispute were too technical to be negotiated; communication between EPA and USNRC is already excellent; such a procedure would merely delay repromulgation unnecessarily; and because the rulemaking has been underway for fifteen years, there is little fundamental dispute over what the major policy and technical issues are. HIGH LEVEL RADIOACTIVE WASTE MANAGEMENT ABROAD Representatives of Canadian, Swedish, and Swiss HLRW management programs described their countries' efforts at repository siting as less pressured for results than the U.S. program. Charles McCombie, of the Swiss radioactive waste disposal cooperative Nagra, said that Switzerland's first goal is technical consensus based on analytical assessment. The Swiss program differs from the U.S. program in that uncertainties do not have to

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management disappear before a decision is made. European programs are more flexible than the U.S. program because repository schedules are tentative, not fixed by law, and the licensing is based on evaluation of safety assessments rather than on strict predetermined quantitative performance requirements. McCombie noted that there is less pressure to license a repository because European countries have accepted that storing the HLRW for 20 to 40 years before isolation in a permanent repository is essential; intermediate storage is planned either on site or in MRS-like facilities. One participant pointed out that both European and Asian countries have made national decisions to rely on nuclear power, and the goal of the licensing processes is to support that decision in a way that is safe and environmentally sound. Every effort is made by the state and the licensing authority to rectify problems so that approval is obtained. The fundamental difference lies in the criteria for success: in the United States, an agency is successful regardless of whether a repository is licensed; abroad, an agency's success depends on the completion of licensing. Therefore, they avoid situations like that in the United States, where the two regulating agencies (EPA and USNRC) and the implementing agency (DOE) operate independently. The European representatives acknowledged that their countries will likely have the same problems as the United States in convincing the public to accept a repository, but public opposition is building more slowly. Another major difference among the programs is that the United States is the only country using a population risk concept and radionuclide release limits instead of limits on individual doses or risks to members of the public. NEED FOR AN OVERALL PUBLIC HEALTH AND SAFETY GOAL Underlying the issues of a probabilistic standard vs. deterministic regulation and of stringency is the broader question of whether the involved federal regulatory agencies and the general public can be assured of adequate protection to health without a public health and safety goal that takes into account the pathways to man. (Such a goal is distinct from the intent, stated in the Supplementary Information that prefaces the Standard, of restricting the amount of risk to future generations to the risk that would be inherent in an equivalent amount of unmined ore.) Such a goal, for example, is set qualitatively for nuclear power plants by the USNRC and is supported by probabilistic quantitative objectives to assure achievement of the primary goal. The lack of a safety goal for repositories is reflected in the nuclear waste community's focus on release limits rather than safety estimates. According to McCombie, the United States lacks a common appreciation of the need for transparency of safety standards. He advocated emulation of the Canadian radioactive waste program, which facilitates public

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Radioactive Waste Repository Licensing: Synopsis of a Symposium sponsored by the Board on Radioactive Waste Management understanding, and advised colleagues in the United States to de-emphasize the licensing aspect of the repository and put the stress on safety. At the symposium, many suggestions were made that a health and safety goal be applied to repository facility licensing in terms of standards, regulatory approaches, risk/benefit balances, and operational requirements. In the absence of a generally accepted public health and safety goal for the Standard governing geologic repositories, major concerns to be resolved include whether the regulatory agencies, in striving for health and environmental protection, can require the applicant to do less than the maximum that is technically feasible, and whether standards/regulations for disposal of HLRW should be promulgated to balance safety/risk and cost.