Opinion ID: 407564
Heading Depth: 2
Heading Rank: 2

Heading: Contemporaneous Explanation

Text: 333 A review of the record reveals that the Commission's expressed purpose in conducting the final S-3 rulemaking had evolved considerably since it had conducted the original rulemaking. 60 Its expressed purpose in conducting the final rulemaking was not to evaluate or select the most effective long-term waste disposal technology, to model precisely all of the fuel cycle impacts from a single reactor, or even to evaluate the likelihood that the nuclear waste could safely be stored in the long term. 334 The NRC's statement of basis and purpose for its final S-3 rule made clear that creation of an S-3 table had become only one part of an ongoing and wide-ranging Commission effort to evaluate long-term nuclear waste disposal issues. The Commission began by noting that a general update of the rule with respect to all aspects of the uranium fuel cycle was in progress. 61 It further noted its intent to conduct a supplementary rulemaking directed at producing and incorporating into the final rule an explanatory narrative summarizing in understandable terms the environmental significance of the table's numerical impact values. 62 Finally, the Commission noted its intent to conduct a parallel generic proceeding-a waste confidence proceeding, now in progress-to consider the most recent evidence regarding the likelihood that nuclear waste can be safely disposed of and when that, or some other off-site storage solution, can be accomplished. 63 335 Accordingly, the Commission's statement of basis and purpose referred again and again to the final rule's limited purpose: to provide a table modeling some, but not all, of the fuel cycle impacts for a typical reactor: 64 336 The table of impacts adopted as a final rule in this proceeding serves as an important first step in this consideration, relieving adjudicatory boards from the need to determine those numerical impacts of the uranium fuel cycle which have been extensively considered in generic rulemaking. 65 337 Because individual licensing boards would incorporate the table into environmental cost-benefit analyses where costs would be measured in terms of the impact of effluent releases on human lives, not in terms of the effluent releases alone, the Commission expressly stated that use of the table in individual licensing will not foreclose discussion of the significance of the release values stated in the table, or of other important aspects of the fuel cycle not addressed by the table. 66 338 In short, the Commission's goal was not to produce an exhaustively comprehensive table of precisely accurate figures as to which all uncertainty had been eliminated. Indeed, had the Commission set that goal as the objective of the rulemaking it could never have produced a Table S-3 at all, since all of the figures stated there were based on some unprovable assumptions, predictions, and generalizations. The Commission candidly acknowledged that its rulemaking necessarily involve(d) a wide-ranging inquiry and a certain amount of speculation. 67 Nevertheless, the Commission chose as a matter of policy not only to acknowledge that uncertainty, but to accept it, and then to proceed in the face of that uncertainty. 68 339 The Commission gave two reasons for creating an admittedly imperfect table of model fuel cycle impact values: its concern that NEPA cost-benefit analysis demanded a prelicensing assessment of the environmental effects of the fuel cycle, generic to all licensing actions; and its determination that such assessment lay beyond the expertise of individual licensing boards: 340 A study of fuel cycle impact thus involves difficult generic analysis and prediction well outside the normal scope of facility-specific subjects dealt with by a reactor licensing board. This does not mean the subject can be ignored or deferred until the fuel cycle facilities themselves come up for licensing. It does mean that in reactor licensing fuel cycle impacts should be treated where possible by generic rulemaking rather than case-by-case adjudication. 69 341 Aware that individual licensing boards would rely heavily on the table in future adjudications, however, the Commission deliberately selected its values so that, taken as a whole, the table would reflect substantial conservatism. 70 So long as the table as a whole was conservative, the Commission assumed, it would adequately serve as a starting point in individual environmental cost-benefit analyses, even if not perfectly detailed and precise.
342 To derive a conservative table of useable estimates amidst uncertainty about future technology, the NRC staff had to select some methodology. The staff chose to analyze intensively the most credible long-term waste disposal method then known-burial of the wastes in a bedded-salt geologic repository several hundred meters below ground-then estimate(d) its impact conservatively, based on the best available information and analysis. 71 Because such a repository had not yet been built, the staff had to make a number of preliminary assumptions even to begin analysis. At the outset, it assumed that an appropriate salt deposit site would be found 72 that the particular salt formation chosen would likely remain essentially undisturbed for millions of years, 73 and that whatever repository built would be designed, operated, and regulated in such a way as to minimize the possibility of long-term failure. 74 343 The staff then analyzed the possibility of a repository failure resulting from two types of events: (1) commonplace occurrences, such as long-term corrosion of waste cannisters and subsequent leakage into the groundwater; 75 and (2) unusual occurrences, such as violent disruption of the repository by sabotage or natural catastrophe. 76 Having thereby established a range of probabilities for potential waste release based on a variety of repository failure scenarios, the staff then used two approaches to assess the consequences to human life of a waste release: a hazard index 77 and a modeling of waste transport to the human environment. 78 Throughout the staff's analysis, working assumptions were expressly spelled out and uncertainties inherent in the models employed were candidly acknowledged. 79
344 The Commission reiterated the staff's assumptions and uncertainties in its statement of basis and purpose. 80 Based on the record compiled by the staff and hearing board, the Commission then found that the 345 characteristics of a bedded-salt repository afford a reasonable basis for the staff's conclusion that the repository can maintain its integrity, provided that sites meeting the selection criteria can in fact be found and developed. 81 346 While agreeing that areas of uncertainty remain regarding both the likelihood of finding a site and the probability that it will perform as expected, 82 the NRC noted that more precise evaluation and selection of the best waste disposal technology were properly the subject of other NRC proceedings. 83 347 Then and only then did the Commission consider whether admitted uncertainties regarding the likelihood of successful waste disposal can or should be reflected explicitly in the fuel cycle rule: 348 On the individual reactor licensing level, where the proceedings deal with fuel cycle issues only peripherally, the Commission sees no advantage in having licensing boards repeatedly weigh for themselves the effect of uncertainties on the selection of fuel cycle impacts for use in cost-benefit balancing. This is a generic question properly dealt with in this rulemaking as part of choosing what impact values should go into the fuel cycle rule. The Commission concludes, having noted that uncertainties exist, that for the limited purposes of the fuel cycle rule it is reasonable to base impacts on the assumption which the Commission believes the probabilities favor, i.e., that bedded-salt repository sites can be found which will provide effective isolation of radioactive waste from the biosphere. 84 349 Based on staff findings of extremely low probabilities of repository failure from either commonplace occurrences or accidental intrusions and an assumption that all volatile radioactive products would be released from a repository before final sealing, the Commission found that taking post-sealing releases as zero does not significantly reduce the overall conservatism of the table. 85 In concluding that the model chosen by the staff to assess waste disposal impacts was reasonable and adequate for the purposes of the rule, the Commission in no way foreclosed reassessment of its conclusions in light of new evidence. Observing that the current rate of growth of knowledge (in this area) is very large, 86 the NRC reiterated that (a) continuing reassessment of the Commission's views on waste disposal is part of the commitment which the Commission has made to Congress. 87