Natural Resources Defense Council, Inc. v. United States Nuclear Regulatory Commission

¶14PER CURIAM:

¶15Judge Bazelon’s opinion constitutes the opinion of the court. Judge George Clifton Edwards, Jr., concurs in all but Part IV-D of the opinion, and Judge Wilkey concurs in only Part IV-D.

¶16BAZELON, Senior Circuit Judge:

¶17These consolidated cases involve the continuing efforts of the Nuclear Regulatory *463Commission (NRC)1 to establish a system by which to consider and disclose the environmental impact of the uranium fuel cycle in compliance with the National Environmental Policy Act (NEPA).2 The present controversy centers upon the radiological effluents associated with the “back end” of the fuel cycle: the reprocessing,3 storage, and “disposal”4 of spent fuel and other wastes. At issue are three versions — the original,5 interim,6 and final versions7 — of the “Table S-3 Rule,” which provide a set of numerical values intended to reflect the environmental effects of the uranium fuel cycle.8 Under the Rule, Table S-3 is to be *466included in the environmental impact statement (EIS)9 of each proposed light water nuclear power reactor, and thereby substitute for repeated individualized consideration of the environmental impact of the fuel-cycle activities needed to support each plant.10

¶18The issues in this case largely concern the use of numerical values to depict the environmental effects of fuel-cycle activities. By describing such effects in this manner, the issue arises whether there is more to the fuel cycle’s environmental impact than the bare numbers in the Table reveal, and, if so, whether licensing boards are prevented from looking beyond the Table to consider additional elements of the fuel cycle’s environmental impact. One omission from the Table is explicit recognition of the uncertainties that underlie the projected effluent releases. This omission is particularly glaring in the Table’s treatment of the long-term effects of solid high-level and transuranic wastes, which remain toxic for at least 250,000 years.11 The Commission ex*467pects to dispose of those wastes, perhaps by first reprocessing a portion of them, and in any event, by burying them in salt mines beneath the continental United States. The Tables indicate that the wastes will have no effect on the environment after they are sealed in salt mines.12 In effect, therefore, the Table S-3 Rules instruct all licensing boards, when analyzing the environmental impact of a particular plant, to conclusively assume that such wastes will emit no radiological effluents into the environment after final burial.

¶19The second omission from the Table is a description of the health, socioeconomic, and cumulative effects of the projected releases. The Table describes effluent releases in units of radioactivity per year. It does not evaluate the actual effects of those releases on human health, or on social and economic well-being, as an increasing number of plants continue to produce wastes. The issue raised by this aspect of the Table is whether the Table S-3 Rule allows licensing boards to take evidence on and consider those effects in individual licensing proceedings.13 Finally, the effluent releases predicted in the Table are based on assumptions concerning the future availability of certain types of waste-management and disposal technology. The issue arises, therefore, whether the Commission has correctly found that the predicted releases represent technological goals that are economically feasible.

¶20We conclude that the Table S-3 Rules are invalid because they fail to allow for proper consideration of the uncertainties concerning the long-term isolation of high-level and transuranic wastes, and because they fail to allow for proper consideration of the health, socioeconomic and cumulative effects of fuel-cycle activities. Therefore, we remand.

¶21I. BACKGROUND

¶22Although a great deal remains to be learned about radioactive wastes, this much is known: 1) many of the wastes remain extremely toxic for a very long time;14*4682) the NRC has yet to settle upon a method for permanently disposing of radioactive wastes;15 and 3) none of the current proposals for disposal is certain to succeed.16 For more than a decade, and in several different arenas, the Natural Resources Defense Council (NRDC) has sought to force the Commission to factor this knowledge into its licensing decisions, each of which represents a decision to create additional nuclear wastes.17

¶23A. The Original Table S-3 Rule

¶24In April 1971, the NRDC attempted to raise the environmental impact of nuclear waste as a relevant consideration in the operating license proceeding for the Vermont Yankee Nuclear Power Station.18 NRDC argued that such a licensing proceeding was the only decisionmaking stage at which the issue could be raised effectively, for at any later stage a commitment to produce potentially dangerous waste would have already been made. The Atomic Safety and Licensing Board (ASLB), however, rejected the NRDC’s request.19 It refused to admit evidence or permit questions on the environmental impact of Vermont Yankee’s spent fuel or other radioactive waste products.20

¶25In June 1972 the Atomic Safety and Licensing Appeal Board (ASLAB) upheld the ASLB’s decision. The Appeal Board based its ruling on the fact that fuel-cycle effects were both speculative and remote. Because spent fuel and wastes would be removed from the plant, the Board stated, their effects should be considered in proceedings to license future reprocessing plants and waste *469repositories — not in Vermont Yankee’s licensing proceeding.21

¶26In November 1972, the Commission responded to the ASLAB’s Vermont Yankee decision by publishing a notice of proposed rulemaking to determine whether, and if so, how, it should consider the environmental impact of the fuel cycle as it continued licensing nuclear facilities.22 The notice proposed two alternatives. The first alternative would have precluded any consideration of the environmental effects of radioactive wastes on the ground that those effects would not significantly affect the outcome of any licensing decision.23 The second alternative would have limited disclosure and consideration of the environmental effects of these wastes to a table of predetermined numerical values, which was reproduced in the notice.24 The values were standardized to represent the expected contribution of one 1,000 megawatt light water nuclear reactor. The Commission staff had already derived the necessary values and reported them in Table S-3 of the Commission’s Environmental Survey of the Nuclear Fuel Cycle.25The Table contained entries for the environmental effects of most stages of the uranium fuel cycle, but it contained no entry for the radiological effluents from solidified high-level and transuranic wastes. These wastes, which must be isolated from the environment for hundreds of thousands of years, were expected to be buried eventually in a federal repository somewhere beneath the continental United States. The original Table contained no values for the environmental impact of this final stage of the fuel cycle because the Commission staff believed that technology would be developed by which to isolate the wastes from the environment for an indefinite period of time.26 Thus, both alternative proposals were based on the assumption that long-term waste-disposal systems, yet to be developed, would work perfectly. On the basis of such assumptions, the Commission proposed to mandate that licensing boards presume, in their decisions to grant nuclear power plant licenses, that there would be no risk of waste-disposal failure.

¶27On April 16, 1974, the Commission adopted the Table S-3 alternative and amended its NEPA regulations to allow for consideration of the environmental effects of the uranium fuel cycle by including Table S-3 in the EIS for each light water nuclear reactor.27 The Rule also provided that the environmental effects of the fuel cycle “shall be as set forth in Table S-3,” and that “no further discussion of such environmental effects shall be required.” 28 In the meantime, the Vermont Yankee plant itself *470had been granted a full-term, full-power operating license,29 and the Appeal Board had expressly declined to reexamine their earlier decisions precluding inquiry into the environmental impact of the fuel cycle.30

¶28The NRDC challenged both the Table S-3 Rule and Vermont Yankee’s license in this court.31 We found that the procedures that the Commission employed in adopting the Rule failed to generate a record sufficient to support the optimistic conclusion that high-level and transuranic wastes would be isolated from the environment for the requisite number of centuries.32 The court noted that the portion of the rule precluding inquiry into these matters was based on a few conclusory reassurances from a member of the Commission’s staff who was not questioned or cross-examined.33 That part of the Rule was therefore held to be arbitrary and capricious, and was set aside and remanded. We also held that in the absence of a valid generic rule, the environmental impact of fuel-cycle activities must be considered in individual licensing proceedings. Because the Commission had granted Vermont Yankee’s operating license without such consideration, we remanded the order granting that license to await the outcome of further generic proceedings.34 These decisions were rendered July 21, 1976.

¶29B. The Supreme Court’s Decision

¶30In April 1978, the Supreme Court reversed this court’s decision to set aside the original Table S-3 Rule,35 finding that we had overturned the Rule because of deficiencies in the Commission’s rulemaking procedures.36 The Court held that if an agency complies with the procedures required by statute, a rule may be struck down because of procedural shortcomings only in unusual circumstances.37 The Supreme Court agreed, however, that the Rule should be vacated if it lacks support in the administrative record, and remanded the case to us “so that the Court of Appeals may review the rule as the Administrative Procedure Act provides.”38 That case, No. 74-1586, is, therefore, among the four consolidated cases now before us.

¶31The Supreme Court also noted that the Commission had promulgated an interim Rule pending the issuance of a final Rule. It stated that this court, on remand, could consolidate the challenge to the original *471Rule with the appeal from the interim rule-making proceeding, which was already pending. The Court further noted that this court could decide those cases on the basis of an expanded record, which is what we have done.39

¶32C. The Interim Table S-3 Rule

¶33On October 18, 1976, in response to this court’s decision but prior to the Supreme Court’s remand, the Commission initiated proceedings to review the waste-management and disposal aspects of the Table S-3 Rule, and to develop a revised and adequately supported fuel-cycle rule.40 The Commission announced that a special Task Force had completed a revised Environmental Survey of the Reprocessing and Waste Management Portions of the LWR Fuel Cycle,41and invited comments on the Survey . and the revised Table S-3, both of which would constitute the basis of a final or interim rule.42 Also in response to this court’s ruling, the Commission had reconvened a licensing board to consider suspending the operating license of Vermont Yankee, which, by then, was fully operational.43 The Commission suspended that proceeding, however, when it decided that an interim rule, similar to the original, could issue shortly.44

¶34In announcing that it was reconsidering the Table S-3 Rule, the Commission stated:

[T]here are still uncertainties in areas such as the effect of waste presence on repository stability; the probabilities and consequences of various types of intrusive acts by humans; the availability of data to be used in modeling studies; the design and regulatory actions needed to minimize possibilities of repository failure; projection of future societal habits and demography; and, finally, the relative importance of the various potential initiating events. Research programs are underway which should resolve most of these uncertainties over the next few years.45

¶35Nonetheless, the Survey and proposed Table S-3 still provided that solidified high-level and transuranic wastes, which were to be buried in a permanent repository, would have no effect on the environment. Unlike the original Table, the revised Table S-3 did contain an entry for solidified high-level and transuranic wastes. It provided that 11 million curies of radiation would be released from the solidified waste per reference reactor year. Under the “maximum effect” column, however, the Table simply stated “Buried at Federal Repository.”46 The materials referenced by the footnotes to the Table make clear that this meant that the radiation would remain wholly contained within the repository once the repository is sealed.47

¶36The NRDC filed comments stating that the Survey and Table were based on only an assumption that technology could be developed to isolate long-term wastes from the environment, and that the consequences of the failure of such development were left unanalyzed. The NRDC’s comments also stated that the numerical values in the Table failed to reveal the health effects of environmental impacts or the cumulative *472effects of the continuous creation of radioactive wastes.48 In addition, the State of New York filed comments objecting to the NRC’s failure to consider the economic feasibility of the projected waste-management and disposal methods.49 The Commission staff and, ultimately the Commission, rejected all of these complaints and refused to modify the proposed rule.50

¶37In March 1977, on the basis of the revised ■Survey and the comments received, the Commission promulgated an interim Table S-3 Rule,51 which, as indicated in the Commission’s notice, explicitly stated that releases from the solidified high-level and transuranic wastes would remain buried in a repository and, therefore, have no effect on the environment.52 Like the original Table S-3 Rule, the interim Rule stated that the environmental effects of the fuel cycle “shall be as set forth in Table S-3,” and that “[n]o further discussion of such environmental effects shall be required.”53 The Commission amended the interim Rule in April 1978, however, to allow licensing boards to consider environmental impacts not specifically “addressed by the Table.”54

¶38In April 1977, the Commission issued an order directing the Appeal Board to reconsider the cost-benefit balances which had been struck in the licensing proceedings of Vermont Yankee and several other plants.55 The following July, the Board ruled that the values in Table S-3 did not change the cost-benefit balance of the Vermont Yankee plant, particularly because the plant was already operating.56 In connection with this reconsideration, the Board expressed *473concern over the proper interpretation of the Table S-3 entry for high-level and transuranic wastes, given the fact that the Commission openly admitted that the assumption of no environmental effect was uncertain.57 The Board strongly implied that its interpretation of that aspect of the Table could alter the outcome of particular decisions.58 Ultimately, however, the Appeal Board concluded that the Commission had intended it to assume that there would be no effluent releases from the permanent repository, once it is sealed.59

¶39In No. 77-1448, the second of the four cases now before this court, NRDC challenges the interim Rule.60

¶40D. The Final Table S-3 Rule

¶41In May 1977, following the adoption of the interim Rule, the Commission reopened hearings to determine whether the interim Rule should be made final or altered in any way.61 The hearings employed some procedures not used in the original rulemaking, and participants were given an additional opportunity to comment on the Hearing Board’s recommendations to the Commission.62 The NRDC criticized the Rule for the failure of the numerical values to communicate either the uncertainties of underlying assumptions, or the health, cumulative, or socioeconomic effects of waste-management and disposal activities.63

¶42The States of New York and Wisconsin again objected to the Commission’s failure to analyze the economic viability of the proposed waste-management and disposal methods. The Commission staff initially argued that the economics of the proposed *474methods should not be considered.64 The Hearing Board, however, and later the Commission, ordered that evidence concerning the economic feasibility of the proposed technologies be considered in the rulemaking.65 The States of New York, Ohio, and Wisconsin submitted such evidence, criticizing the cost projections and the economic feasibility of the anticipated disposal methods.66 In response, the Commission staff and industry groups submitted evidence in support of the cost estimates used.67

¶43In July 1979, the Commission promulgated the final Table S-3 Rule.68 The final Rule made only minor adjustments in the Table’s numerical values and left unchanged the assumption that radiological effluents from solidified high-level and transuranic wastes would have no effect on the environment once sealed in a federal repository.69 The Commission also stated its intention to add an explanatory narrative to Table S-3 to convey the significance of the numerical values.70 In addition, the Commission confirmed its intention that the Table should be supplemented by individual presentations on the health, socioeconomic, and cumulative effects of fuel-cycle activities, pending the adoption of such a narrative.71

¶44As it had done before, the Commission noted the uncertainties regarding both the likelihood of finding a site for a permanent repository and the likelihood that the repository will perform as expected.72 Nonetheless, the Commission explicitly rejected the option of expressing uncertainties in the Table S-3 Rule. The Commission stated:

In view of the uncertainties noted regarding waste disposal, the question then arises whether these uncertainties can or should be reflected explicitly in the fuel cycle rule. The Commission has concluded that the rule should not be so modified. 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 purpose of the fuel cycle rule it is reasonable to base impacts on the assumption which the Commission be*475lieves the probabilities favor, i.e., that bedded-salt repository sites can be found which will provide effective isolation of radioactive waste from the biosphere.73

¶45Thus the Commission’s final Rule, like its two predecessors, does not permit licensing boards to consider either the risk that permanent waste management facilities will not be developed or the risk that they will fail to perform as intended if they are developed. In addition, the Commission accepted the Hearing Board’s recommendation and conclusion that the projected facilities were economically feasible because they were not “outlandishly expensive.”74

¶46In 79-2110, the State of New York challenges the final Rule on the ground that the Commission’s finding of economic feasibility is arbitrary and capricious. In 79-2131, the NRDC challenges the final Rule because it inadequately discloses, and fails to allow proper consideration of, the uncertainties underlying the environmental impacts embodied in the final Table.

¶47II. STANDARDS OF REVIEW

¶48As the Supreme Court has stated, we must review the Table S-3 Rule under the standards provided in the Administrative Procedure Act (APA).75 The applicable provision of the APA is section 706(2)(A), which provides that a reviewing court shall “hold unlawful and set aside agency action, findings and conclusions found to be — arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.”76 In this case, both the “arbitrary and capricious” and the “not in accordance with law” standards are appropriate. Under the latter standard, we must determine whether the Table S-3 Rule, as applied to individual licensing decisions, violates NEPA,77 while under the “arbitrary and capricious” standard, our task is to “consider whether the decision was based on a consideration of the relevant factors and whether there has been a clear error of judgment.”78 Of course, other laws must give content to the phrase “relevant factors.” Because the Table S-3 Rule governs the preparation of environmental impact statements for individual nuclear reactors, NEPA provides the relevant factors that the Commission was required to consider in formulating the Rule. Therefore, there is an area of overlap between the “arbitrary and capricious” standard and the “in accordance with law” standard.

¶49III. NEPA

¶50It is well settled that the licensure of a nuclear power plant constitutes a “major Federal actionf] significantly affecting the quality of the human environment.” 79 Therefore, there can be no doubt that the Commission must comply with section 102(2)(.C) of NEPA80 prior to licensing such a plant. That section provides:

*476The Congress authorizes and directs that, to the fullest extent possible ... all agencies of the Federal Government shall . . . include in every recommendation or report on proposals for legislation and other major Federal actions significantly affecting the quality of the human environment, a detailed statement by the responsible official on—

(i) the environmental impact of the proposed action, [and]

(ii) any adverse environmental effects which cannot be avoided should the proposal be implemented, [and]

(v) any irreversible and irretrievable commitments of resources which would be involved in the proposed action should it be implemented.

¶51Furthermore, as the Supreme Court has stated,

[i]t is hard to argue that [nuclear wastes] do not constitute “adverse environmental effects which cannot be avoided should the proposal be implemented,” or that by operating nuclear power plants we are not making “irreversible and irretrievable commitments of resources.”81

¶52Therefore, the Commission must fully consider and disclose the environmental impact of nuclear wastes during the course of its decisions to license nuclear power plants.82

¶53It is well recognized that section 102(2)(C) of NEPA has a dual function: Its first function is “to inject environmental considerations into [federal agencies’] decisionmaking processes];”83 and its second function is to inform the public of the nature of the agencies’ decisions, and to “inform the public that [agencies have] considered environmental concerns in [their] decisionmaking processes].”84 With respect to these statutory purposes, the Supreme Court has stated, and recently reiterated,85 that “[t]he thrust of § 102(2)(C) is . . . that environmental concerns be integrated into the very process of agency decisionmaking. The ‘detailed statement’ it requires is the outward sign that the environmental values and consequences have been considered during the planning stage of agency actions.”86 In Calvert Cliffs’ Coordinating Committee, Inc. v. AEC,87 one of the first cases decided under NEPA, this court analyzed these aspects of the Act in further detail. We stated that “[compliance to the ‘fullest’ extent possible would seem to demand that environmental issues be considered at every important stage in the decisionmaking process concerning a particular action — at every stage where an overall balancing of environmental and nonenvironmental factors is appropriate and where alterations might be made in the proposed action to minimize environmental costs.”88 Thus, decisionmaking under NEPA must be organized in such a manner that all of the reasonably foreseeable environmental effects of a proposed action enter into an agency’s decision to take the action.89 The environmental impact statement, the centerpiece of NEPA’s procedural requirements, both facilitates and provides a record of this decisionmaking process. As we noted in Calvert Cliffs, two related pur*477poses of the EIS are to provide evidence that the mandated decisionmaking process has taken place, and to “allow [] those removed from the initial process to evaluate and balance the [environmental] factors on their own.”90 The decisionmaking structure mandated by section 102(2)(C) is not inherently flexible, nor are the particular requirements that it entails discretionary.91 It is the role of the courts to ensure that agencies comply with these provisions of NEPA.92

¶54The NRC’s promulgation of the Table S-3 Rule represents both an attempt to implement, and a limitation on other means of implementing, these aspects of NEPA.93 The validity of the Rule, therefore, turns largely on whether the decisionmaking structure it mandates conforms to the procedures, and thereby poses no obstacles to the substantive calculus, required by NEPA.94 Specifically, we must determine whether the Table S-3 Rule (1) violates NEPA; or (2) is arbitrary and capricious, given the considerations made relevant by NEPA.

¶55IV. ANALYSIS

¶56Petitioners, the NRDC and the State of New York, challenge the Table S-3 Rules on three grounds. First, the NRDC argues that the original, interim and final versions of the Table S-3 Rule are arbitrary and capricious and not in accordance with NEPA because they preclude proper consideration and disclosure of uncertainties that underlie the Tables’ numerical values. Second, the NRDC argues that the original and interim Table S-3 Rules are arbitrary and capricious and not in accordance with NEPA because they preclude proper consideration and disclosure of the tangible environmental effects of the waste created by nuclear power plants. Finally, the State of New York argues that the release levels projected in the final Table S-3 Rule are based on a finding of economic feasibility that was arbitrary and capricious.

¶57We conclude that the Table S-3 Rules are arbitrary and in violation of NEPA because they fail to allow for consideration of uncertainties underlying the assumption that no radiological effluents will be released into the biosphere once wastes are sealed in a permanent repository. Similarly, we conclude that the original Rule and the interim Rule, prior to amendment, are arbitrary and in violation of NEPA in their failure to allow consideration of health, socioeconomic, and cumulative ef*478fects of fuel-cycle activities. We also conclude, however, that the Commission’s finding that the predicted waste-management and disposal methods would be economically feasible was neither arbitrary nor capricious.

¶58A. The Zero-Release Assumption and Uncertainty Over Permanent Storage

¶59The original, interim, and final Rules all prohibit licensing boards from considering the uncertainties surrounding the Table S-3 Rules.95 In particular, no challenges were allowed to the assumption that a suitable final repository site would be found, constructed, and would operate flawlessly.96 The assumption underlying Table S-3 that no radiological effluents will be released from the permanent repository, once the repository is sealed, can be interpreted in either of two ways: It can be read as a factual finding, or, as a decisionmaking device by which the Commission retains exclusive responsibility for considering the uncertainties concerning long-term waste disposal. Particularly in the interim and final Rules, it appears that the latter is the correct characterization.97 Nonetheless, for the sake of completeness, we review the validity of the zero-release assumption under each interpretation.98

¶601. The Zero-Release Assumption as a Factual Finding

¶61As stated in Part II, above, a reviewing court must set aside an agency finding as arbitrary if it determines that the finding is not based upon consideration of relevant factors or if it is based on a clear error of judgment.99 The “relevant factors” in this case are those whose consideration is mandated by NEPA.

¶62Among the environmental costs that an agency must consider under section 102(2)(C) are significant environmental risks — probabilities or possibilities of environmental damage.100 Such risks may be *479present due to the underlying randomness of nature. Or they may be due to human uncertainty over either the character of both random and nonrandom phenomena or the ability of future technology to cope with those phenomena. Regardless of the source, environmental risks are environmental costs that must be factored into the NEPA calculus.101 They must also be included in an EIS. Where such risks are attributable to a lack of knowledge, the agency can be asked to do no more than to reveal that which it knows and that which it does not know. It may not be permitted, however, to do any less.102

¶63An agency could state in an EIS, as a matter of factual prediction, that a particular environmental effect will not have to be endured as a result of a proposed action. Of course, if it believes that to be the case, it can omit entirely any discussion of the would-be effect. Similarly, an agency could provide, by generic rule, that a particular environmental effect will not be caused by a class of actions, and that the effect should not be addressed in individual environmental impact statements. Because the risk of an environmental effect is the overriding “relevant factor” that an agency must consider in making such a factual finding, the agency may treat an environmental effect in this manner only if it finds that there is no significant risk that the environmental effect will occur. It may not do so if it finds only that the effect is unlikely to occur. Otherwise, NEPA’s requirement that agencies consider and disclose uncertainty would be subverted. When faced with uncertainty concerning an environmental effect, an agency could evade its obligations under NEPA simply by finding *480that the effect will not occur. Thus, in the context of compliance with NEPA’s procedural requirements, a court must interpret an agency’s finding of no environmental effect as a finding that there is no significant risk of an environmental effect.

¶64It is against that background that we review the Commission’s finding that nuclear wastes that are sealed in a permanent repository will have no impact on the environment. When read as a finding that such wastes pose no significant risk of environmental damage, we conclude that the finding represents a “clear error in judgment.” 103

¶65In each version of the Table S-3 Rule, the Commission based its zero-release assumption on a prediction that technology would be developed by which to isolate long-lived wastes from the biosphere indefinitely. In the Environmental Survey,104 which constituted the technical basis of the original Table S-3, the Commission staff reported that “[i]t was planned to construct a Federal repository in a salt mine for long-term geological storage of solid high-level wastes by the mid-1970’s. However, subsequent events have deferred the site selection and construction of such a facility.” 105 The plan at that time, therefore, was to build a Retrievable Surface Storage Facility (RSSF) in which to store the wastes until a permanent repository became available. The Environmental Survey said no more than that the permanent repository that would be developed “is intended to isolate the waste from man and the biosphere.” 106 A few years later, in the report that formed the basis of the interim and final Rules, the Commission staff continued to assume that a bedded-salt repository could be developed, but noted that other systems were also under consideration.107 The other systems included the use of alternative geological media for isolation, and the “eliminat[ion of] portions of the wastes from existence on earth.”108 The Commission still had not worked out the technological details of any permanent disposal techniques. Nonetheless, it concluded that a system would be developed that would fully protect the environment. Until such a system is developed, the Commission still plans to store waste in an RSSF.109

¶66Scientists with the United States Geological Survey testified to the technical, uncertainties surrounding the zero-release assumption.110 Similarly, the Report to the President by the Interagency Review Group on Nuclear Waste Management111 pointed out that risk assessments “based on idealized repository characteristics ... are subject to significant uncertainties,”112 and concluded that the “zero release of radionuclides [from a permanent repository] cannot be assured.”113 In addition, the record indicates that serious concerns were raised over the likelihood of developing the human institutions or political consensus necessary to establish and maintain the hypothesized fa*481cilities.114 The IRG Report noted, in fact, “that the resolution of institutional issues may well be more difficult than finding solutions to remaining technical problems.” 115 Moreover, even the Commission’s own staff recognized that there were many uncertainties surrounding the assumption that a permanent repository could be developed that would fully contain the effluents emitted from high-level and transuranic wastes.116

¶67There is no need, however, to comb the record further for evidence of uncertainty, for the Commission itself has explicitly — although somewhat belatedly- — acknowledged its presence. In its Statement of Consideration for the final Rule, “the Commission note[d] and agree[d] . . . that areas of uncertainty remain regarding both the likelihood of finding a site and the probability that it will perform as expected.” 117 The Commission nevertheless accepted its staff’s zero-release assumption, stating that the staff’s conclusion that there would be no release from the sealed repository had a “reasonable basis.” Moreover, revealing even more of the uncertain nature of its judgment, the Commission concluded that the evidence, although “tentative” and general in nature, “favors the view that suitable sites can be found.” 118

¶68The evidence in the record and the Commission’s own recent statements indicate the existence of such uncertainty concerning permanent disposal of high-level and transuranic wastes that the zero-release assumption, taken as a finding of fact, cannot stand. If read as a finding of no significant risk, which we acknowledge may not have been its intent, the zero-release assumption represents a self-evident error in judgment. Therefore, we conclude that the finding is arbitrary and capricious.

¶692. The Zero-Release Assumption as a Decisionmaking Device

¶70As stated above, the Commission’s zero-release assumption is probably characterized better as a decisionmaking device than as a finding of fact, particularly in the interim and final Rules. By instructing licensing boards to assume that nuclear waste will have no impact on the environment once it is sealed in a repository, the Table S-3 Rule has served to allocate to the Commission sole responsibility for considering the risk that long-lived wastes will not be disposed of with complete success. Under that decisionmaking scheme, the Commission considered the possibility of unsuccessful isolation of wastes prior to promulgating the Table S-3 Rule. The Rule itself represents the Commission’s statement that *482it has done so, and that licensing boards should go forward licensing plants without duplicating its effort.

¶71Just as the Commission avoided describing the zero-release assumption as a finding of fact, it did not describe the assumption in precisely these terms either. In more recent years, however, the Commission has, at various times, seemed to indicate that this is essentially its view of the assumption. For instance, in its Statement of Consideration for the Final Rule, the Commission stated:

In view of the uncertainties noted regarding waste disposal, the question then arises whether these uncertainties can or should be reflected explicitly in the fuel cycle rule. The Commission has concluded that the rule should not be so modified. 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 purpose 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.119

¶72Our inquiry, therefore, must focus on whether the decisionmaking device of the Rule — including the Commission’s investigation, analysis, and deliberation prior to the Rule’s promulgation — has provided the type of consideration and disclosure of uncertainties that NEPA requires.

¶73In general, an agency in the position of the Commission is free to implement NEPA through generic rulemaking. If certain types of environmental costs are common to a class of actions, NEPA does not require that an agency engage in duplicative and possibly inconsistent individual determinations, but allows it, in the alternative, to conduct a single rulemaking to determine generic values to be considered together with case-specific costs and benefits in individual proceedings.120 Similarly, if there are both costs and benefits common to a class of individual actions, an agency is free, not only to determine generic values for those costs and benefits, but also to weigh the costs and benefits against each other to produce a generic “net value.” To the extent that certain costs and benefits cannot be compared on a single scale, the generic determination of net value is necessarily more complex. It may involve instructing case-specific decisionmakers to insert fictional values into their cost-benefit analyses. A generic rule might be promulgated, for instance, designating that certain entries on one side of an individual actions’ ledger should be treated as zero, or nonexistent, and assigning offsetting values to certain entries on the other side of the ledger. The agency may even determine that certain classes of generic costs and benefits so balance each other that both can be treated as zero for purposes of individual decisions. In the abstract, such generic structuring of individual decisionmaking is acceptable as long as it is based on the agency’s reasoned judgments about how the generic costs and benefits weigh against each other.121 In the course of such a generic rulemaking, however, the agency must consider and disclose the actual environmental effects it has assessed in a manner that will ensure that the overall process, including both the generic rulemaking *483and the individual proceedings, brings those effects to bear on decisions to take particular actions that significantly affect the environment. If the overall decisionmaking process allows for this type of consideration — which is precisely that described in Calvert Cliffs’122— the agency may then direct case-specific decisionmakers to abide by the generic rule, and thereby preclude their reevaluation of either the underlying determinations of costs and benefits or the process by which those costs and benefits were assessed against each other.

¶74Under the Table S-3 Rule, licensing boards consider virtually all factors relevant to the construction and operation of a nuclear power plant. The zero-release assumption, however, excludes from their consideration two factors: 1) uncertainty concerning the integrity of the permanent repository, if such a repository is ever built; and 2) uncertainty over whether and when such a repository, or equivalent system of disposal, will be developed. These uncertainties reflect two environmental costs of licensing a plant. The first cost is the risk that wastes created by the plant will eventually damage the environment by emitting radiological effluents from a faulty permanent repository. The second cost is the risk that waste created by the plant will have to remain in another type of repository — possibly on site123 — and emit radiological effluents prior to permanent disposal, if such disposal ever comes about. Hence, the zero-release assumption prevents licensing boards from considering two environmental costs.

¶75The Commission argues that its consideration and disclosure of these costs prior to promulgating the Rule was sufficient under NEPA, and that the licensing boards need not reconsider them. We disagree. Although the Commission did consider these uncertainties, it did not do so in a manner that would allow licensing decisions to be affected — either directly or indirectly — by the risk that nuclear waste will not be successfully isolated from the environment indefinitely. After recognizing that there are uncertainties concerning the permanent storage of nuclear wastes, the Commission simply ruled that licensing decisions should be made on the basis of cost-benefit analyses that omitted the costs represented by those uncertainties. It did not rule that the costs were insignificant,124 nor did it rule that they were outweighed by generic benefits that would also be excluded from licensing boards’ consideration. In effect, therefore, the Commission directly contravened NEPA’s requirement that environmental costs be considered “at every stage where an overall balancing of environmental and nonenvironmental factors is appropriate.” 125 The risks entailed by the possible failure to develop a successful waste-dispos*484al system were never part of any “balancing.” They were considered alone, in a vacuum, and then excluded from the licensing boards’ balancing. The process that began with the proposal of the Table S-3 Rule does not allow the uncertainties concerning permanent storage to play a role in the ultimate licensing decision. That omission, and hence, the Rule, which causes it, constitutes a blatant violation of NEPA.

¶76In arguing that it adequately considered the uncertainties surrounding long-term storage, the Commission emphasizes the fact that these uncertainties represent generic costs.126 The Commission recognizes that cost-benefit balances differ among individual plants and that these uncertainties are relevant costs, particularly if a plant’s cost-benefit balance is close.127 Nonetheless, the Commission asserts that “[it remains] a generic question how to weigh these uncertainties [in individual cases].”128 To the extent that the Commission is arguing that the uncertainties can be assessed generically, and that the attendant risks can be measured generically, we agree. As we have stated above, however, the Commission cannot find the environmental cost represented by the uncertainties to be zero unless their cost is, in fact, zero.129 Similarly, although the Commission can assess generic costs in a generic rulemaking, it must, in some manner, factor its assessment into ultimate decisions to license plants.130 One way in which the Commission could do so would be to follow the course that it has taken with respect to other environmental costs of licensing nuclear power plants: It could assess and evaluate the uncertainties and attendant risks, and instruct licensing boards to consider and disclose them in a uniform manner. To the extent that the Commission is arguing, however, that generic costs need not be considered at all within the context of balancing the costs and benefits of licensing decisions, we strongly disagree. The fact that certain environmental costs can be assessed generically does not imply that they can be excluded entirely from the balancing process that must precede an agency’s decision to take a major action.131

¶77The Commission also argues that its disclosure of uncertainties in its Statements of Consideration and in its staff reports, satisfies NEPA’s requirement of a “detailed statement.” We recognize that the NRC, particularly in promulgating the final Rule, has disclosed the nature of many of the uncertainties surrounding the storage of long-lived wastes.132 NEPA, however, requires an agency to do more than to scatter its evaluation of environmental damage among various public documents. As stated above, an agency must disclose environmental costs — including uncertainties concerning such costs — in a manner that proves to the public that the agency has properly considered the environmental costs of its action.133 In this case, because the Commission has not properly considered such costs, the issue whether it has disclosed enough raw information is beside the point.

¶78In sum, when viewed as an administrative decisionmaking device, the zero-release assumption of Table S-3 constitutes a violation of NEPA. Under section 706(2)(A) of *485the APA, it is, therefore, “not in accordance with law.”134

¶79Alternatively, the same result can be reached under the arbitrary and capricious standard.135 Under that standard, as stated above, our inquiry focuses upon whether the zero-release assumption is based on “consideration of the relevant factors.” 136 Under NEPA, significant uncertainty surrounding the environmental effect of a proposed action is relevant to an agency’s decision to rule generically that the effect will not occur. For an agency to go forward in the face of significant uncertainty and issue such a rule indicates either a failure to consider a relevant factor or a clear error in judgment. Because that is precisely what the Commission did in promulgating the Table S-3 Rule, we could also conclude that its action was arbitrary and capricious.137

¶80B. Consideration of Other Uncertainties

¶81The NRDC seems to argue that- Table S-3 masks uncertainties underlying waste-management activities other than permanent disposal.138 It has not, however, indicated where those uncertainties lie or what values in the Table obscure them. Similarly, the Commission has responded to the NRDC by focusing primarily on the uncertainties surrounding the successful development of a permanent repository.139 As a result, we face considerable difficulty reviewing this issue.

¶82Table S-3 lists several gaseous and liquid radiological effluents along with low-level, high-level and transuranic solid wastes.140 The gaseous and liquid effluent releases are expected to occur at the early stages of the waste-management process, before the wastes are solidified and prepared for per*486manent disposal. The staff reports supporting the Table S-3 Rules indicate that there is indeed uncertainty concerning the predictions of these releases. In contrast to its method of projecting releases from the solid waste stored in a permanent repository, however, it appears that the Commission used “worst case” estimates in determining Table S-3’s values for gaseous and liquid releases. The Commission assumed, for example, that all of the tritium, krypton-85 and carbon-14 in spent fuel would be discharged into the environment during reprocessing.141 The Commission also seems to have used equally conservative assumptions in determining Table S-3’s values for releases of iodine-129, iodine-131 and other radioactive gases.142 One issue before us, therefore, is whether the Commission violated NEPA in treating these uncertainties in this manner, rather than by representing uncertainty itself in the Table. We hold that it did not.

¶83As we have emphasized above, NEPA requires an agency to consider the environmental risks of a proposed action in a manner that allows the existence of such risks to influence the agency’s decision to take the action.143 An agency can do this by having the appropriate decisionmakers consider all that is known and unknown about the risks before deciding whether to take an action. Or, it can organize its decisionmaking process in such a manner that the appropriate decisionmakers consider only the upper bound of reasonably foreseeable environmental costs. If, after considering that level of environmental damage, the decisionmakers conclude that the proposed action is worth its societal costs, full account will have been taken of the action’s environmental impact. Similarly, if the upper bounds of environmental risks are disclosed in an EIS, Congress, the public, and any interested agency can effectively assess for themselves whether the agency has proposed an action that is not worth its environmental costs. Either method of considering and disclosing uncertainties surrounding an environmental effect is acceptable under NEPA.144 Thus, to the extent that the Commission has listed the upper bound of reasonably foreseeable gaseous and liquid effluent releases in Table S-3, we hold that it has complied with NEPA.

¶84It is impossible for this court to determine whether there are other numerical values in Table S-3 that mask uncertainties without using such conservative heuristic devices as a worst-case scenario. We expect, however, that the Commission’s consideration of uncertainties underlying the zero-release assumption will encompass any significant uncertainties underlying other values in the Table.145

¶85C. Consideration of Health, Socioeconomic and Cumulative Effects

¶86Petitioner NRDC also challenges the original and interim Rules for failing to allow proper consideration or disclosure of the actual environmental impact of the fuelcycle.146 In all versions of the Rule, Table S-3 lists the environmental effects of the fuel cycle in terms of the quantity of land, water, and energy used, and of heat, chemicals and radioactivity released. It does not reveal the meaning of those impacts in terms of human health or other environmental values. The Table does not, for instance, indicate the number of cancer deaths or genetic defects to be expected. Nor does it refer to potential social, psychological, and economic disruptions that might accompany the siting of waste repositories, the construction of reprocessing and dispos*487al facilities, or the maintenance of safety and security over long periods of time. Furthermore, the Table, which is based on the incremental impact of one prototypical reactor operating for one year, assumes that there will be no cumulative effects of licensing scores of reactors each of which will remain in operation for thirty to forty years.

¶87There can be no dispute that NEPA requires the health, socioeconomic and cumulative impacts of a proposed action to be disclosed in an EIS.147 Otherwise, the statement could not fulfill its purpose of informing the public, Congress, and other decisionmakers of the environmental impact of the action.148 Nor could the environmental cost-effectiveness of a proposed action be compared to that of alternative actions if the environmental effects of each are not disclosed in such commensurable terms. In this case, therefore, it is not releases of curies that Congress wanted disclosed; it is the effects, or environmental significance, of those releases. Those effects are defined by the CEQ regulations to include:

ecological (such as the effects on natural resources and on the components, structures, and functioning of affected ecosystems), aesthetic, historic, cultural, economic, social, or health, whether direct, indirect, or cumulative.149

¶88Hence, the issue before us is whether the provisions of the original and interim Rules that governed the use of Table S-3 allowed for proper consideration of these environmental values.

¶89Our resolution of that issue is complicated by the fact that the relevant provisions of the Rule have undergone several transformations since their initial promulgation. The original and interim Rule provided that “the contribution of the environmental effects of .. . fuel cycle activities shall be as set forth in the following Table S-3 ... [and] no further discussion of such environmental effects shall be required.”150 Prior to 1977, individual licensing boards interpreted this clause to preclude their consid*488eration of the environmental significance of the numerical values listed.151 In its January 1977 Hartsville decision, however, the Commission’s Appeal Board ruled that a licensing board must consider the relative health effects of a proposed nuclear power plant and a coal-fired alternative.152 Then, in April 1978, the Commission promulgated a “clarifying” amendment to the interim Table S-3 Rule which specifically provided that health effects could be considered by individual licensing boards.153 In addition, the Commission broadened the scope of licensing boards’ consideration by amending the restriction on such consideration to read: “No further discussion of the environmental effects addressed by the Table shall be required.”154 The amended interim Rule did not, however, explicitly address the consideration of any type of impact other than health effects. Ultimately — or perhaps penultimately — in the final Rule, which the NRDC does not challenge, the Commission resolved the issue by requiring licensing boards to consider the socioeconomic and cumulative effects in addition to the health effects of the releases projected in the Table.155 At that point, the Commission also indicated that it would conduct further proceedings to determine such health, socioeconomic and cumulative effects on a generic basis, and thereby eliminate the need for case-by-case consideration.156

¶90The NRDC argues that the original, the interim and the amended interim Rules violated NEPA by preventing licensing boards from considering the health, socioeconomic and cumulative effects of fuel-cycle activities.157 The Commission responds by arguing that each version of the Rule complied with NEPA because none explicitly precluded such consideration. We find the Commission’s argument unpersuasive.

¶91The original Rule and the interim Rule, prior to its amendment, stated that “the contribution of the environmental effects of ... fuel cycle activities shall be as set forth in the following Table S-3 ... [and] no further discussion of such environmental effects shall be required.”158 The term “such” refers to the phrase “the contribution of the environmental effects of ... fuel cycle activities.” Therefore, the Rules unambiguously stated that a licensing board’s consideration and an EIS’s disclosure of the environmental effects of fuel-cycle activities could be limited to the information contained within the four corners of Table S-3. Moreover, it appears that the impact of the Rules was to preclude further consideration or disclosure. The background of the Rules makes this conclusion even clearer. Recall that the proposal for the original Rule suggested two ways of dealing with the environmental effects of fuel-cycle activities.159 One approach was to ignore those environmental effects in individual licensing proceedings as the Appeal Board had allowed in Vermont Yankee ; and the other, which was adopted, was to factor those effects into individual cost-benefit analyses by using Table S-3. Since the Table S-3 Rule was adopted as an alternative to a rule that would have permitted no consideration or disclosure of the environmental effects of the fuel cycle, it was reasonable for licensing boards and interested parties to conclude that the Rule limited consideration of such environmental effects to the introduction of the Table.160

¶92*489The Commission itself has recognized as much. For instance, in promulgating the final Rule, the Commission stated that the Table S-3 Rule “at least initially was apparently interpreted as cutting off further discussion of fuel cycle impacts” 161 and that

the rule in practice [was applied] as allowing fuel cycle impacts to be addressed in reactor licensing proceedings solely by the formal act of displaying Table S-3 in impact statements, with no further discussion. In particular, impact statements prepared by the staff did not analyze fuel cycle impacts in terms of health effects which might be caused by the radioactive releases tabulated in the rule and did not discuss socioeconomic or cumulative impacts.162

¶93The original Rule and the interim Rule, prior to its amendment, thus effectively eliminated the consideration and disclosure of the health, socioeconomic and cumulative impacts of fuel-cycle activities. The NRC, therefore, in promulgating the original and interim Rules violated NEPA.163

¶94The Commission argues that the Appeal Board’s Hartsville164 decision eliminated any preclusive effect that the Rules may have had on the consideration of health, socioeconomic and cumulative impacts.165 We disagree. First, the decision in Harts-ville was itself ambiguous. Although holding, in general, that a licensing board had to examine the comparative health effects of a nuclear plant and the alternative of a coal-fired plant, the Appeal Board specifically refrained from considering any environmental effect of waste-management and disposal activities, awaiting direction from the Commission in the then-pending interim Table S-3 Rule.166 Second, the Hartsville decision only addressed health effects in the context of comparing a nuclear plant with a coal-fired alternative.167 Finally, the Hartsville decision did not address cumulative or socioeconomic effects. Thus, even after Hartsville, it remained apparent that the consideration of health, and particularly, cumulative and socioeconomic impacts of the fuel cycle was precluded by the Table S-3 rules.168

¶95*490Not until the Commission’s amendment of the interim Rule did it become reasonably clear that health, cumulative, or socioeconomic impacts could be considered in individual licensing proceedings under the Table S-3 Rule.169 Even with the amendment, in fact, there could be some doubt as to whether or not cumulative or socioeconomic impacts were still precluded from consideration. As stated above, the amended Rule and its Statement of Consideration referred explicitly to health effects, but not to socioeconomic or cumulative effects.170 Nevertheless, it did replace the language that had effectively limited licensing boards’ consideration and disclosure of the environmental effects of fuel-cycle activities to the values listed in Table S-3. The new language precluded consideration of the effects “addressed by the Table.”171 Because socioeconomic and cumulative effects were not addressed by the Table, the terms of the amended Rule did not prevent licensing boards from considering such effects and should not have prevented such effects from being disclosed in environmental impact statements. Thus, the amendment of the interim Rule eliminated the NEPA violation.

¶96In view of the foregoing, we hold that the original Table S-3 Rule and the interim Table S-3 Rule, prior to amendment, were invalid. Although the amended interim Rule, and later the final Rule, allowed consideration of health, socioeconomic, and cumulative effects, a number of licenses issued under the original and unamended interim Rules have been challenged. Several of those cases are currently pending in this circuit awaiting this decision.172

¶97D. Economic Feasibility

¶98Petitioner, the State of New York, and Intervenor, the State of Wisconsin, argue that the effluent-release values listed in Table S-3 assume the use of technology that is economically infeasible, even if it is technologically feasible. They argue, first, that the Commission applied an improper standard of economic feasibility in concluding that its projected releases are reasonably foreseeable; second, that the Commission’s cost estimates are incorrect, and third, that the Commission failed to explain the basis of its finding of feasibility.173 We conclude that, although the Commission could have been clearer in setting out its reasons for determining that Table S-3’s predictions are economically feasible, the determination itself was not arbitrary or capricious.174 Therefore, we affirm the Commission on this issue.

¶99*491As Judge Tamm stated in our initial decision in this case, “[t]he Commission should be able to supply the court with a statement of the methods by which its staff arrived at the figures embodied in Table S-3 and by which [its staff] concluded that the waste storage problem is already technologically and economically soluble.”175 The values in Table S-3 are based on assumptions concerning the types of technology that will be used in waste-management and disposal activities.176 For those values to represent reasonably foreseeable environmental effects, as required by NEPA, the use of that technology must be reasonably foreseeable. It must, therefore, be both technologically and economically feasible.177

¶100In concluding that the facilities required to meet the effluent projections of Table S-3 are economically feasible, the Commission applied a standard of whether the facilities are “prohibitively” or “outrageously expensive.”178 Although the Commission’s articulation of the standard is somewhat nebulous, we interpret it to mean that a facility would be economically feasible if its expected cost is no more than the nuclear power industry will pay, under the regulation of the NRC or with the aid of reasonably foreseeable public subsidization.179

¶101New York and Wisconsin argue that “[e]conomic feasibility must be determined in the context of private enterprise, and the question is whether the costs are feasible for the profit-making sector.” 180 The basis of their argument seems to be that if it is very expensive to limit effluent discharges to the levels predicted in the Table, the nuclear power industry may economize, at the expense of the public, by allowing higher discharges.181 We find this approach untenable. The standard of economic feasibility may be based on realistic, conservative, and reasoned forecasts of who will have to pay the costs of waste management and disposal, and under what type of compulsion.182 The history of the federal government’s commitment to regulate and subsidize the nuclear power industry, and to operate certain nuclear facilities itself, is clear and long-standing. Moreover, at least the final repository envisioned by the Commission is expected to be developed and operated by the federal government.183 The Commission, in making its prediction of economic feasibility, therefore, was justified in making the reasonable assumption *492that the regulatory structure of the nuclear power industry would remain basically unchanged.184 Under that structure, the NRC will have the power to regulate the industry in such a manner that no private firm will be able to, let alone have an incentive to, cut its costs by allowing the release of more effluents than those projected in Table S-3. If it turns out that the industry cannot pay the full cost of managing and disposing of the waste it has created, it is reasonable to expect the federal government to help out, for society as a whole can be expected to prevent private industry from taking chances in handling nuclear waste. Because the possibility that a firm will have in a socially irresponsible manner is well within the control of the Commission, we hold that the Commission correctly determined that the standard of economic feasibility is that level of costs that the industry in combination with the federal government can reasonably be expected to pay. Of course, we can only hope that the Commission, in fact, exercises its control over the industry in a manner consistent with the public interest.185

¶102New York and Wisconsin challenge, as arbitrary and capricious, both the cost estimates that the Commission accepted,186 and the conclusion that such costs would be feasible.187 The major elements of the Commission’s cost estimates that New York and Wisconsin challenge are the discount rate used and the estimate of decommissioning costs.

¶103In preparing the cost estimates in question, the Commission staff discounted future expenditures to present values at a ten percent rate. In the rulemaking proceeding and again before this court, New York objected to both the discounting procedure and the discount rate used, arguing that a discount rate from zero to two percent would be more appropriate.188 We find, however, that although this argument may be meritorious, it does not undermine the Commission’s finding of feasibility, because both the Hearing Board and the Commission used discount rates of zero and two percent in estimating the range of expected costs.189

¶104New York and Wisconsin also argued before the Commission, and now before this court, that the Commission underestimated, by a factor of ten, the cost of decontaminating and decommissioning (D&D) a reactor.190 Although the Hearing Board took evidence on D&D costs, the Commission ultimately decided that the consideration of *493such costs should be relegated to individual licensing proceedings.191 D&D costs were consequently held to be irrelevant to the economic feasibility of the Table S-3 values. The effluent values in Table S-3 nevertheless continue to include effluents emitted from decommissioned plants.192 We must assume, therefore, that licensing boards will use Table S-3’s values attributable to decommissioning only if they are assured that the decommissioning method assumed by the Table is reasonably likely to be the method used for the individual reactor under consideration. If not, we assume that the licensing board will be free to consider the full environmental costs of whatever decontamination and decommissioning method is expected to be used.193 Thus to this limited extent, we interpret the Table S-3 Rule to be nonpreemptive. Therefore, we reject New York’s and Wisconsin’s contention that Table S-3 is invalid because of inaccuracies in the D&D cost estimates.

¶105Using a variety of discount rates and including the staff’s estimated decommissioning costs,194 the Commission found that the projected waste-management and disposal facilities would entail capital costs of between $71 million and $76 million,195 and operating costs ranging from 0.4 mills/KWh to 1.4 mills/KWh for the once-through cycle and 1.9 mills/KWh to 3.9 mills/KWh for the uranium-only recycle option.196 The Commission observed that such costs represented less than 10% of the capital costs and less than 5% of the operating costs of a typical reactor.197 The Commission found these costs to be feasible simply because they represent only a small fraction of the total cost of building and operating a reactor.198 New York and Wisconsin argue that the finding is arbitrary and capricious because the Commission did not explain why, even under the Commission’s own standard, these costs are feasible. We conclude that, although the Commission’s reasoning is far from transparent, its finding of economic feasibility is neither arbitrary nor capricious. We recognize that an agency must provide a rational connection between facts found and conclusions reached, and a court may not supply a reasoned basis for an agency’s action.199 Nonetheless, a court must uphold a decision of less than ideal clarity if the agency’s path may rea*494sonably be discerned; 200 and in reviewing an agency’s decision, a court can only ensure that the agency properly considered all relevant factors, and that its conclusion does not represent a clear error in judgment.201 In this case, it is apparent that by comparing the projected costs of waste management and disposal to current reactor costs, the Commission was implicitly considering the level of private and, if necessary, public resources that could reasonably be expected to be available for these activities.202 Because these waste-management and disposal expenses represent a comparatively small addition to the resources needed to build and operate a reactor, and because a plant need not be built if it appears that those expenses will render the plant unprofitable, we cannot say that the Commission clearly erred in determining that sufficient resources would be available. The Commission has thus addressed the relevant factor of the availability of private and public resources and reached a conclusion that is within the range of reasonability. We conclude that the Commission’s finding of economic feasibility was not arbitrary or capricious, and dismiss the petition in No. 79-2110.

¶106CONCLUSION

¶107For the foregoing reasons, we hold that the original, interim and final Table S-3 Rules are invalid due to their failure to allow for proper consideration of the uncertainties that underlie the assumption that solidified high-level and transuranic wastes will not affect the environment once they are sealed in a permanent repository. We also hold that the original Rule and the interim Rule, prior to its amendment, are invalid due to their failure to allow for proper consideration of the health, socioeconomic and cumulative effects of fuel-cycle activities. We conclude, however, that the Commission’s finding of economic feasibility was not arbitrary or capricious. We, therefore, vacate all three Rules. Licenses already granted under the Rules are not at issue in this action, and we accordingly express no view as to their validity. The validity of those licenses will be determined in subsequent proceedings.203

¶108Vacated and Remanded.

¶337GEORGE CLIFTON EDWARDS, Jr.,* Circuit Judge,

¶338concurring in part and dissenting in part.

¶339This case may prove to be one of the most important cases to be decided by the United States courts in this century. ' The United States Supreme Court, in reversing this court’s previous remand of this case to respondent, the Nuclear Regulatory Commission (NRC or Commission), emphasized the magnitude of the problem it was sending back for our reconsideration:

The Commission itself, in a pamphlet published by its information office, clearly recognizes that these wastes “pose the most severe potential health hazard. ...” U.S. Atomic Energy Commission, Radioactive Wastes 12 (1965). Many of these substances must be isolated for anywhere from 600 to hundreds of thousands of years. It is hard to argue that these wastes do not constitute “adverse environmental effects which cannot be avoided should the proposal be implemented,” or that by operating nuclear power plants *495we are not making “irreversible and irretrievable commitments of resources.” 42 U.S.C. §§ 4332(2)(C)(ii), (v).

¶340Vermont Yankee Nuclear Power Corp. v. Natural Resources Defense Council, 435 U.S. 519, 538-39, 98 S.Ct. 1197, 1208-09, 55 L.Ed.2d 460 (1978), rev’g Natural Resources Defense Council v. Nuclear Regulatory Commission, 547 F.2d 633 (D.C.Cir.1976).

¶341In this case we are required to review the continuing effort of the NRC to pit human intelligence against the most primordial force of nature. This force, when involved in its most awful manifestation, exceeds the power of flood, fire, pestilence, earthquake, hurricane and volcano. In this century, it has been demonstrated in this and other countries that this force can be employed for peace and war — for warming a baby’s bottle and for nuclear holocaust.

¶342It is not the function of the judicial branch either to initiate or to halt the development of a nuclear power industry. These national policy choices are constitutionally vested in the President and the Congress of the United States, and they have been made in favor of proceeding.

¶343This court’s limited function is to determine from the agency record before us whether or not the Commission’s decision to adopt certain Tables S-3, 10 C.F.R. § 51.-20(e) (1981), was “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.”1 The S-3 Tables instruct the licensing boards, which are delegated the task of licensing all new nuclear power plants, that there will be “zero” release of emissions or releases so small as to be insignificant,2 from the nuclear waste accumulated or to be accumulated from plants now licensed or which may be licensed during the 2,500 centuries it will take for that waste to decay. Thus the Commission seeks to preclude further licensing hearings from considering the hazards from unanticipated, accidental or willful release of emissions beyond those specitied in the Tables from the highly toxic and potentially explosive wastes generated by nuclear power plants during temporary storage, reprocessing, transportation and 250,000 years of burial. 46 Fed.Reg. 15154, 15156 (March 4, 1981).

¶344I concur fully with Judge Bazelon’s opinion for the court, except for the cost issue.

¶345I write separately in concurrence to express deep concern for additional problems and uncertainties that I believe to be buried in the naked figures and enigmatic footnotes of the Tables S-3 that this appeal requires us to review. Further, in computing the cost of the proposed nuclear waste disposal system, the NRC has not included the costs of surveillance of and guarding the public from the toxic effects from nuclear waste at all disposal sites for somewhere between 10,000 to 250,000 years. As a consequence, I dissent from the opinion for the court on this issue and state my reasons at the end of this opinion.

¶346My concurrence with Judge Bazelon is based on the reasoning he has ably set forth. But I find what appear to me to be even more substantial reasons to agree with his result. An integral part of the “back end” of the nuclear fuel cycle involves the NRC’s plan for reprocessing spent fuel rods. Reprocessing involves extraction from the spent fuel rods of either the remaining uranium and plutonium (uranium and plutonium recycle) or just the remaining uranium (uranium-only recycle). Both elements can be prepared as fuel usable in light-water reactor power plants. The uranium can be enriched and again fashioned into uranium-based fuel rods; in the alternative, the plutonium can be combined with uranium to form mixed oxide fuel rods. There are many indications in this record that the Commission originally intended to use both uranium and plutonium extracted by reprocessing as supplementary fuel in all nuclear power plants, licensed or to be licensed.

¶347*496On April 7, 1977, a presidential order indefinitely suspended reprocessing of spent fuel. 13 Weekly Comp, of Pres. Doe. 506. A new presidential statement on nuclear energy policy, however, dated October 8, 1981, “lift[ed] the indefinite ban which previous administrations placed on commercial reprocessing activities in the United States.” 17 Weekly Comp. of Pres. Doc. 1102. There is now reason to believe that the Commission will proceed with plans to reprocess spent fuel rods thus extracting both uranium and plutonium.

¶348Table S-3 in its final form purports to summarize all “releases” that may be expected in the entire nuclear fuel cycle, except for radon and technetium, which are irrelevant to our present considerations. Moreover, in a proposed “Narrative Explanation of Table S-3,” the NRC states that “the environmental impacts from reprocessing and related waste management activities are nearly identical for the recycling of uranium and plutonium, and for the recycling of uranium only, as fuel in nuclear power reactors.” 46 Fed.Reg. 15154, 15161 (March 4, 1981).

¶349The proposed narrative avoids discussing the potential environmental impacts of plutonium. The Commission has not, however, disavowed its option to use both uranium and plutonium as reactor fuel — probably in the form of mixed oxide fuel. The NRC may well read any final approval of the S-3 Tables by the federal courts as foreclosing any further public hearings or litigation over the matter.

¶350Absent any clear indication to the contrary from the Commission, I feel prudence requires this court to assume that approval of Tables S-3 would be read by the Commission as judicial sanction for its originally intended — and now presidentially permitted — employment of plutonium as reactor fuel.

¶351Plutonium is the most dangerous substance yet known in the history of the world. Airborne, the tiniest speck of it breathed into a human being will produce lung cancer. Twenty pounds of this powder can be made into a nuclear bomb with the explosive force of the atomic bombs that destroyed Hiroshima and Nagasaki in the fall of 1945. The Commission’s originally contemplated nuclear waste disposal scheme included reprocessing of all spent fuel rods from all nuclear power plants now licensed (71) or in contemplation (190). Such reprocessing, depending on the number of plants in operation, would extract each year 35,000 to 93,500 pounds of plutonium 3 in the form of plutonium oxide. The plutonium, in the form of mixed oxide fuel, would then be transported by truck or rail through many heavily populated areas to all nuclear power plants wherever located in the nation and stored until it is consumed as nuclear fuel.

¶352If this scheme is executed according to what I perceive to be NRC’s plan, many private corporations will continually have on hand substantial stocks of the most lethal weapons material ever produced.

¶353Unlike spent fuel rods, plutonium oxide powder can be approached by human beings without fear of radiation. If sealed in an airtight container, it can be transported without harm to the bearer. Also, it is estimated that many thousand people in the United States have the knowledge necessary to fashion a nuclear bomb from this material.4

¶354In the dangerous world in which we live, attempts by foreign or domestic terrorists to divert plutonium oxide to international or domestic blackmail or catastrophic destruction must be anticipated.

¶355*497How NRC contemplates protecting this huge amount of hazardous material from forcible seizure on the highways and rail lines of the United States, and from theft or illegal diversion from storage at between 71 and 190 nuclear power plants is most inadequately dealt with in this record.

¶356Finally, the ancient question, “But who is to guard the guards themselves?” is pertinent. The nuclear weapons of the United States are closely guarded by its armed forces. Their employment is subject to command controls so carefully devised that they terminate in the hands of the President of the United States. Yet it appears that the NRC plans to ship bomb-grade materials freely by road or rail, guarded by civilian employees of the private corporation that secures the reprocessing contract. 10 C.F.R. § 70 (1981). And it appears that the NRC may place supplies of plutonium oxide in the form of mixed oxide fuel with its awesome power on the premises of a total of 71 to 190 nuclear power plants under the control of private corporate officers chosen by and responsible to as many private corporate boards of directors. 10 C.F.R. § 72 (1981).

¶357In the long history contemplated for the nuclear power adventure, we cannot be certain that the raw power placed in so many private hands will never be used against the security of our people or of our form of government.

¶358Any failure to deal with the hazards of this plan may be read by the NRC as validation sub silentio of a plan involving incredible dangers. In its original consideration of using atomic energy for production of electric power, Congress repeatedly required “the protection of the health and safety of the public.” For the reasons which follow, I would not risk the dangers and uncertainties contained in the S-3 Tables without a prior remand of the NRC reprocessing, transportation and storage plans for thorough briefing and argument as to the legality of said plans for the use of plutonium as fuel under the public health and safety requirements of the Atomic Energy Act of 1954. 42 U.S.C. §§ 2012(d), (e), 2133(b), (d), 2232(a) (1976).

¶359THE THREE S-3 TABLES

¶360In this case we are now reviewing three variations of Table S-3: an original version, an interim version and a final version. For purposes of this appeal, the differences between the three versions are inconsequential. To illustrate something about the nature of the problem with which this court has been faced, I print the final version of Table S-3 in full:

¶361

¶362*498

¶363*499

¶364*500

¶36510 C.F.R. § 51.20(e) (1981).

¶366As of this date the Commission has not finally5 adopted any explanation of Table S-3, except to the degree that such may be found in the footnotes to the Table and in the briefs filed by the Commission.

¶367Turning to the Table itself, the critical language may be found on the fifth from the last line of the Table, which reads:

“TRU and HLW (deep) .... 1.1 X 107 Buried at Federal Repository.”

¶368Translated into possibly more understandable English, “TRU and HLW” mean transuranic and high level waste. “([D]eep)” is the sole stated explanation of the contemplated storage or disposal of such waste under the Commission’s present thinking. The figure 1.1 X 10 to the 7th power refers to a total of 11 million curies per nuclear reactor per year. In a footnote keyed to the Table Heading, the Commission does elucidate further, as follows:

In some cases where no entry appears it is clear from the background documents that the matter was addressed and that, in effect, the Table should be read as if a specific zero entry had been made.

¶369Table S-3 n.l.

¶370This innocent sounding language actually stands for the Commission’s holding that 11 million curies of high level radioactive waste per year for each of the presently licensed reactors will be temporarily stored, reprocessed, transported, and then buried and contained deep underground at some unascertained place in some undetermined *501stratum6 at some undetermined time without any release at all of toxic effluents. The life of presently constructed reactors is estimated to be 30 to 40 years. See Proposed Appendix A, Narrative Explanation of Table S-3, 46 Fed.Reg. 15154, 15162 n.2 (Mar. 4, 1981). This means that within the lifetime of the 707 presently licensed nuclear power plants, there will be accumulated for disposal at least 2,100 plant-years of radioactive waste, each plant-year representing by Commission estimate 11 million curies.

¶371If the mathematics involved is not sufficiently impressive, it may be appropriate to point out that a “curie” is defined as “a measure of the number of atoms undergoing radioactive disintegration per unit time and is 37 billion disintegrations per second, or about the rate of. decay in 1 gram of natural radium.” C. Fox, Radioactive Wastes 11 n.* (rev. ed. 1969).

¶372If no other nuclear power plant is licensed or brought on line, the task of the Commission will involve containment in one or more federal repositories of radioactive waste sufficient to generate 854,700,000,-000,000,000,000 (854.7 quintillion) disintegrations per second. Since the decay of radioactive waste spontaneously gives off substantial heat, the problem of preventing accidental or deliberate emission is central to any design that may be proposed for the federal repository. The gradual decay of radioactivity will extend, as the Supreme Court pointed out, from 600 to hundreds of thousands of years. Vermont Yankee, 435 U.S. at 538, 98 S.Ct. at 1209. Yet the Commission contends that this mass of energy and toxic waste (plus possibly two and one-half times more, which may be added by additional nuclear power reactor licensing) can and will be contained with “zero” release. This must be read as meaning no impact at all on the human race in its turbulent occupancy of this biosphere for a minimum period of 250,000 years.

¶373THE COMMISSION’S WASTE DISPOSAL PLAN

¶374Licensing of nuclear power reactors began in 1958. Although some 82 licenses have been issued since 1958, several of those plants are no longer operating. At present, 71 reactors are “licensed for operation,” although not all are currently on line.8 The record before us contains published studies of various proposals for handling high-level nuclear waste for over 250,000 years. Many are in conflict. And one important aspect of the Commission’s original plan, the reprocessing of spent fuel rods, had been in suspension from 1977 until October 8, 1981.

¶375Originally, the Commission’s thinking appears to have encompassed consideration of at least the following elements:

¶3761) Containment buildings for spent fuel rods constructed at each nuclear power plant. These buildings are operated as an integral part of the plant and are guarded within the private power company’s perimeter fences. No other temporary, interim, or permanent storage facility for commercial high-level nuclear waste has yet been built.

¶377As a consequence, spent nuclear fuel is currently accumulating in all nuclear power reactor on-site waste storage facilities — in many instances in quantities far in excess of the originally contemplated storage capability. For example, the Vermont Yankee Nuclear Power Station in Vernon, Vermont, a relatively recent entry on the nuclear scene, was designed to store a maximum of 1,000 spent fuel rods. The Vermont Yankee Nuclear Power Corporation has now been given permission by the NRC to store *5022,400 such spent fuel assemblies there. It is estimated that the plant can operate only until 1987 under this grant of authority, unless, presumably, some now nonexistent interim or permanent storage facility is provided or authority is granted for the spent fuel rods to be stacked even closer.

¶3782) The NRC’s original assumption was that all spent fuel produced by nuclear power reactors would be reprocessed before it was stored. It was also contemplated that the residue of high level waste, particularly plutonium, would be greatly diminished in volume in the process. Only this residue after such extraction was scheduled for storage in the permanent repository. As will be indicated below, this plan is now at least partially back in place.

¶379In fact, a plant for reprocessing spent fuel was built by private industry at West Valley in New York State. It was small; it produced high levels of radioactive effluent releases. See 44 Fed.Reg. 45862, 45370 (Aug. 2, 1979). The operation proved to be uneconomical and was abandoned. Three other more sophisticated reprocessing plants — one actually constructed in Barn-well, South Carolina, and the others planned for Oak Ridge, Tennessee, and Marion, Illinois — were contemplated as a basic part of the NRC’s nuclear waste disposal plan. This record indicates that thus far no reprocessing of spent nuclear fuel, except in small experimental amounts, has occurred.9

¶3803) The NRC also contemplates an interim storage facility. This was described as a retrievable surface storage facility (RSSF). Scheduled to be built about 1980, the RSSF was thought to be capable of storing high-level waste for up to 100 years. The facility would have been built at ground level or slightly below. The high-level waste was to be placed in canisters capable of containing toxic emissions. The dissemination of heat from the decay processes would be accomplished by bringing containment canisters into contact with a coolant, either water or air. Each canister was then to be stored and subjected to cooling for 100 years in the RSSF before being moved to permanent storage.

¶381No such facility has ever been built.

¶3824) Most Commission documents indicate that all high-level waste ultimately will be placed in a federal repository for permanent disposal. The most frequently cited plan, as indicated earlier, is for deep burial in geologic salt deposits.10 Studies of salt bed deposits have been made, the results of which the Commission staff regards as favorable to permanent containment.

¶383THE REVIEW STANDARD

¶384The statute under which the Supreme Court has directed us to review this case is the Administrative Procedure Act, 5 U.S.C. §§ 551-59, 701-06 (1976). In applicable part the Act says:

To the extent necessary to decision and when presented, the reviewing court shall decide all relevant questions of law, interpret constitutional and statutory provisions, and determine the meaning or applicability of the terms of an agency action. The reviewing court shall-—

(1) compel agency action unlawfully withheld or unreasonably delayed; and

(2) hold unlawful and set aside agency action, findings, and conclusions found to be —

(A) arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law;

(B) contrary to constitutional right, power, privilege, or immunity;

(C) in excess of statutory jurisdiction, authority, or limitations, or short of statutory right;

(D) without observance of procedure required by law;

*503(E) unsupported by substantial evidence in a case subject to sections 556 and 557 of this title or otherwise reviewed on the record of an agency hearing provided by statute; or

(F) unwarranted by the facts to the extent that the facts are subject to trial de novo by the reviewing court.

¶385Id.§ 706 (emphasis added).

¶386The critical language to which the Supreme Court directed our attention, Vermont Yankee, 435 U.S. at 535 n.14, 98 S.Ct. at 1207 n.14, is found italicized above. The Supreme Court has unanimously interpreted this language as follows:

Under the “arbitrary and capricious” standard the scope of review is a narrow one. A reviewing court must “consider whether the decision was based on a consideration of the relevant factors and whether there has been a clear error of judgment. . . . Although this inquiry into the facts is to be searching and careful, the ultimate standard of review is a narrow one. The court is not empowered to substitute its judgment for that of the agency.” Citizens to Preserve Overton Park v. Volpe, supra,[401 U.S.], at 416 [91 S.Ct. at 823]. The agency must articulate a “rational connection between the facts found and the choice made.” Burlington Truck Lines v. United States, 371 U.S. 156, 168 [83 S.Ct. 239, 246, 9 L.Ed.2d 207] (1962). While we may not supply a reasoned basis for the agency’s action that the agency itself has not given, SEC v. Chenery Corp., 332 U.S. 194, 196 [67 S.Ct. 1575, 1577, 91 L.Ed. 1995] (1947), we will uphold a decision of less than ideal clarity if the agency’s path may reasonably be discerned. Colorado Interstate Gas Co. v. FPC, 324 U.S. 581, 595 [65 S.Ct. 829, 836, 89 L.Ed. 1206] (1945).

¶387Bowman Transportation, Inc. v. Arkansas-Best Freight System, Inc., 419 U.S. 281, 285-86, 95 S.Ct. 438, 441-42, 42 L.Ed.2d 447 (1974).

¶388This court has repeatedly cited and followed Bowman and other Supreme Court authority on the arbitrary and capricious standard:

It is axiomatic that we may not substitute our judgment for that of the agency. Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814 [823], 28 L.Ed.2d 136 (1971). Yet our review must be “searching and careful,” id.,and we must ensure both that the Commission has adequately considered all relevant factors, see id.,and that it has demonstrated a “rational connection between the facts found and the choice made,” Burlington Truck Lines, Inc. v. United States, 371 U.S. 156, 168, 83 S.Ct. 239, 246, 9 L.Ed.2d 207 (1962).

¶389Home Box Office, Inc. v. FCC, 567 F.2d 9, 35 (D.C.Cir.) (per curiam), cert. denied, 434 U.S. 829, 98 S.Ct. 111, 54 L.Ed.2d 89 (1977). Accord, United States Lines, Inc. v. Federal Maritime Commission, 584 F.2d 519, 526 (D.C.Cir.1978); Ethyl Corp. v. EPA, 541 F.2d 1, 34-36 & n.74 (D.C.Cir.) (en banc), cert. denied sub nom. E. I. duPont de Nemours & Co. v. EPA, 426 U.S. 941, 96 S.Ct. 2662, 49 L.Ed.2d 394 (1976).

¶390“ZERO” RELEASE AT THE FINAL REPOSITORY

¶391On this issue I am in full agreement with Judge Bazelon’s opinion and will add only a few paragraphs in support thereof. I agree that it is arbitrary and capricious for the NRC to close off discussion of the grave problems involved in building a permanent repository for all nuclear waste by categorical determination in Table S-3 that there will be zero releases. As I read this record, neither the Commission nor the Commission staff really defend the zero-release conclusion for any purpose other than to prevent discussion of the issue at licensing hearings. This despite the fact that both Commission and staff recognize that present scientific information strongly suggests that there will be releases of gaseous nuclides during the substantial period of time before the repository is closed. Their studies have shown a probability that transportation and storage canisters designed to contain radiological emissions will corrode and disintegrate in time, releasing their contents. The Commission staff contemplates some escape *504of radionuclides either by gaseous emission or ground water migration. In the proposed Narrative, the Commission staff, at least tentatively, holds that these emissions and migrations will occur “early” in the 250,000-year life of the federal repository and that risks therefrom will be “acceptable.” It is not clear whether the risks become acceptable before or sometime during the first 10,000 years of decay.

¶392The following Table depicts the periods of toxicity of just a few of the various isotopes found in the high-level wastes that may be stored in the federal repository:

Half-Life Period of Toxicity

Element (In years) (In years)

Plutonium-239 24,000 250,000 (approx.)

Strontium-90 28 600-1,000

Cesium-137 30 600-1,000

Technetium-99 210,000 2,000,000 (approx.)

¶393The hope and expectation is really that the impact of the releases will be insignificant on human beings.

¶394Even this last conclusion is subject to very significant uncertainty. As yet undetermined amounts of fissionable materials (markedly reduced, however, if reprocessing is employed) will be emplaced in the repository. In 250,000 years there may be one or more ice ages. See 46 Fed.Reg. 15154, 15172 (Mar. 4, 1981). The probability of container corrosion, the certainty of heat from the quintillions of disintegrations of radioactive wastes, the probable contact with ground water, added to the possibility of geologic disturbance by such forces as glacier, earthquake, or volcanic eruption, all tend to create significant uncertainties. The NRC relies on two studies for its conclusion that the uncertainties involved in waste disposal do not mandate that it alter the zero-release value. 44 Fed.Reg. 45362, 45367 n.19, 45368 & n.24 (Aug. 2, 1979). One study is that of the Interagency Review Group, Report to the President by the Interagency Review Group on Nuclear Waste Management (March 1979) (hereafter IRG Report). The IRG admits, however, that there is a large gap between actual and theoretical capabilities in the technology of nuclear waste disposal. Thus, while the IRG Report may correctly conclude geologic disposal is feasible, it cannot be relied upon to prove that radiological emissions will be zero. The IRG Report concedes as much when it states, “[I]n addition to technical evaluation, a societal judgment that considers the level of risk and the associated uncertainty will be necessary.” Id. at 42.

¶395In the opening pages of the revised Report, the Group states that safe disposal requires a program “whose resolution will clearly require an unprecedented extension of capabilities in rock mechanics, geochemistry, hydrogeology and long-term predictions of seismicity, volcanism, and climate.” Id. at 3. It later summarizes, “The risk assessments performed to date . . . have . . . been based on idealized repository characteristics and are subject to significant uncertainties.” Id. at 45. It then specifically described some of the remaining problems:

The IRG would like to emphasize, however, that risk assessment computations are needed which are site specific in the origin of their data and in their application and only such assessments can truly apply to a specific site. Some uncertainties about the level of risk will always remain both because of the current state of the methodology of risk assessment and because of its inherent limitations.

Uncertainties associated with risk assessment derive from lack of data, lack of experience, inability to identify all release mechanisms for radionuclides, the natural variability in physical properties of geologic media, and inability to predict long-term geologic and climatic processes and social evolution. All of these uncertainties are neither additive nor of equal significance. An important aspect of the research remaining to be done is to understand how each enters into the overall uncertainty of the calculation of risk.

¶396Id. at 46.

¶397It concludes that further study of the problem is necessary to reduce uncertainties:

*505Significant institutional difficulties are involved in: marshalling the resources and programs capable of accurately detailing site suitability criteria and establishment of standards; thoroughly investigating possible sites; accurately assessing site characteristics in light of the technical criteria; carrying out credible analyses of the risks; obtaining agreement on site selection; getting the facility approved and licensed; providing for careful construction and operation of the repository (including safe transportation and handling of the wastes); mitigating accidents and responding to repository failure if that occurs; and providing adequate, long-term monitoring. The level of difficulty of all these problems could increase with the size of the nuclear waste inventory and its rate of growth. Institutions that can cope on a small scale may fail as the demands placed on them multiply. The IRG believes that a more detailed analysis of logistical and other institutional problems which would arise out of attempting to manage wastes on the scale require[d] should be undertaken.

¶398Id. at 88 (emphasis added).

¶399The Commission’s leap from its hopes for safe containment to its conclusion of zero release is, as Judge Bazelon concludes, arbitrary and capricious.

¶400THE PLUTONIUM ISSUE

¶401The Commission’s brief argues that all three of the fuel-cycle rules should be upheld by this court. As previously indicated in this opinion, the Commission has stated that Table S-3 was designed to cover the entire back-end of the fuel cycle. As a consequence, this panel’s affirmance of the validity of Table S-3, if certiorari were denied or the case affirmed by the Supreme Court, could be taken by the Commission as final approval of its original and present plans for reprocessing spent fuel, fabricating uranium and plutonium into mixed oxide fuel therefrom, and shipping this fuel to nuclear reactors all over the nation.

¶402A. Presidential Concern About Reprocessing

¶403The lethal character of plutonium and its potential for use in nuclear bombs evoked expressions of concern from two successive Presidents, Gerald Ford and Jimmy Carter, about the reprocessing of nuclear waste and the separation of bomb-grade plutonium. This concern resulted in April 1977 in a Presidential statement, issued by President Carter, suspending all NRC plans for reprocessing spent nuclear fuel. This statement reads:

There is no dilemma today more difficult to resolve than that connected with the use of nuclear power. Many countries see nuclear power as the only real opportunity, at least in this century, to reduce the dependence of their economic well-being on foreign oil — an energy source of uncertain availability, growing price, and ultimate exhaustion. The U.S., by contrast, has a major domestic energy source — coal—but its use is not without penalties, and our plans also call for the use of nuclear power as a share in our energy production.

The benefits of nuclear power are thus very real and practical. But a serious risk accompanies worldwide use of nuclear power — the risk that components of the nuclear power process will be turned to providing atomic weapons.

We took an important step in reducing the risk of expanding possession of atomic weapons through the Non-Proliferation Treaty, whereby more than 100 nations have agreed not to develop such explosives. But we must go further. The U.S. is deeply concerned about the consequences for all- nations of a further spread of nuclear weapons or explosive capabilities. We believe that these risks would be vastly increased by the further spread of sensitive technologies which entail direct access to plutonium, highly enriched uranium, or other weapons usable material. The question I have had under review from my first day in office is how can that be accomplished without forgoing the tangible benefits of nuclear power.

*506We are now completing an extremely thorough review of all the issues that bear on the use of nuclear power. We have concluded that the serious consequences of proliferation and direct implications for peace and security — as well as strong scientific and economic evidence— require

—a major change in U.S. domestic nuclear energy policies and programs; and

—a concerted effort among all nations to find better answers to the problems and risks accompanying the increased use of nuclear power.

I am announcing today some of my decisions resulting from that review.

First, we will defer indefinitely the commercial reprocessing and recycling of the plutonium produced in the U.S. nuclear power programs. From our own experience, we have concluded that a viable and economic nuclear power program can be sustained without such reprocessing and recycling. The plant at Barnwell, South Carolina, will receive neither Federal encouragement nor funding for its completion as a reprocessing facility.

Second, we will restructure the U.S. breeder reactor program to give greater priority to alternative designs of the breeder and to defer the date when breeder reactors would be put into commercial use.

Third, we will redirect funding of U.S. nuclear research and development programs to accelerate our research into alternative nuclear fuel cycles which do not involve direct access to materials usable in nuclear weapons.

Fourth, we will increase U.S. production capacity for enriched uranium to provide adequate and timely supply of nuclear fuels for domestic and foreign needs. …

¶40413 Weekly Comp. of Pres. Doc. 506 (1977) (emphasis added).

¶405The Commission recognized the impact of the Presidential order in a “Memorandum of Decision” issued December 23, 1977. In that memorandum, the Commission announced its decision:

(1) to terminate the GESMO proceeding;

(2) to terminate the proceedings on pending or future plutonium recycle-related license applications, except for—

(a) proceedings on licenses for the fabrication or use of small quantities of mixed oxide fuel for experimental purposes, and

(b) those portions of proceedings which involve only spent fuel storage, disposal of existing waste, or decontamination or decommissioning of existing plants;

(3) to reexamine the above matters after the completion of the ongoing domestic and international studies of alternative fuel cycles, now expected to take about 2 years;

(4) to publish the draft safeguards supplement to the GESMO documents as a staff technical report;

(5) as a consequence of the above decisions, to withdraw the November 1975 policy statement on mixed oxide fuel, 40 Fed.Reg. 53056; and

(6) to reserve for decision, if it arises, the question whether a facility such as the Allied-General Nuclear Services (AGNS) Nuclear Fuels Plant at Barn-well, South Carolina, may be licensed for experimental and feasibility purposes on a non-commercial basis to investigate processes which support the nation’s non-proliferation objectives.

¶406This memorandum provides the reasons for the December 23 decision.

¶407BACKGROUND

¶408The use of mixed oxide fuel has been before the Commission and its predecessor, the AEC, for more than a decade. In 1960, Nuclear Fuel Services (NFS) began a small reprocessing plant at West Valley, New York, which operated from 1966 through 1971. Construction of the AGNS Plant at Barnwell began in 1970 and parts of the plant are now essentially complete. AGNS’ application for an operating license is currently before the Commission. In 1973, Westinghouse Electric Corporation (Westinghouse) re*507quested a construction authorization letter for a mixed oxide fuel fabrication plant near Anderson, South Carolina. Finally, Exxon Nuclear Company, Inc., (Exxon) is currently seeking permission to construct a reprocessing plant at Oak Ridge, Tennessee.

¶409The health, safety, and environmental impacts of the wide-scale use of mixed oxide fuel were evaluated in the draft Generic Environmental Statement on Mixed Oxide Fuel, published in August 1974. The draft GESMO prompted many public comments, including a January 1975 letter from the President’s Council on Environmental Quality which stressed the need to consider the safeguards aspects of wide-scale plutonium recycle. In May 1975, the Commission announced its provisional intention to supplement GES-MO with an analysis of safeguards and to limit interim licensing of recycle-related activities to experimental purposes. 40 Fed.Reg. 20142 (May 8, 1975). Over 200 public comments were received in response. In November 1975, the Commission published a policy statement which announced that safeguards alternatives would be a part of the GESMO decision, provided for hearings on the GESMO documents, and stated criteria under which interim licensing of nonexperimental recycle-related activities would be considered. 40 Fed.Reg. 53056 (November 14, 1975), corrected 40 Fed.Reg. 59497 (December 24, 1975). The United States Court of Appeals for the Second Circuit affirmed the Commission’s hearing procedures but held that interim licensing of recycle-related activities on a commercial scale violated the National Environmental Policy Act (NEPA). Natural Resources Defense Council, Inc. v. Nuclear Regulatory Commission, 539 F.2d 824 (1976), vacated and remanded to determine mootness, 434 U.S. 1030 [98 S.Ct. 759, 54 L.Ed.2d 777] (January 16, 1978).

¶410The final impact statement on health, safety, and the environment was published in August 1976 and associated public hearings began that November. The hearings progressed through questioning of the NRC staff on its testimony and the filing of written testimony by all participants and proposed questions on that testimony.

¶411Congress and other parts of the Federal Government, members of the public, and experts in the national security field have continued to express concerns related to the nuclear weapons proliferation risks of plutonium recycle technology as it is presently conceived. That technology produces separated plutonium, which can be used in the production of nuclear explosives. The concern is basically that the international spread of plutonium recycle technology for commercial nuclear power production creates a risk that nonnuclear weapons states might turn plutonium from the commercial fuel cycle to the production of nuclear explosives. See generally Senate Committee on Government Operations, 94th Cong., 1st. Sess., Peaceful Nuclear Exports and Weapons Proliferation — A Compendium (Comm. Print 1975). Moreover, a decision by the United States to proceed with commercial plutonium recycle domestically would undermine U.S. efforts to restrain premature international resort to plutonium. The risk led the Commission in late summer 1976 to direct its staff to begin an analysis for GESMO for international proliferation risks and safeguards.

¶412On October 28, 1976, President Ford discussed these risks in his Statement on Nuclear Policy, and stated that the nation “should pursue reprocessing and recycling in the future only if they are found to be consistent with our international [nonproliferation] objectives” (p. 4).

¶413President Carter expressed his concern over the proliferation risks of plutonium recycle and the potential availability of other weapons-grade materials in the nuclear fuel cycle in his April 7, 1977, Statement on Nuclear Power Policy. As part of his response to these risks, the President stated that the Administration’s policy would be to defer indefinitely domestic plutonium recycle and to initiate a multinational evaluation of alternative *508fuel cycles in order to promote the government’s international nonproliferation goals. The GESMO hearings were indefinitely postponed by the GESMO Hearing Board, and on May 3 the Commission announced that it intended to reassess “the future course and scope of GESMO, the review of recycle-related license applications, and the matter of interim licensing.” 42 Fed.Reg. 22964 (May 5, 1977). Public comments were received in June.

¶414On May 5, Marcus Rowden, then Chairman of the Commission, wrote the President requesting his views on these matters. Stuart Eizenstat, Assistant to the President for Domestic Affairs and Policy, responded for President Carter on October 4. The letter (reprinted at 42 Fed. Reg. 57186 (November 1, 1977)) states that “the President believes that his nonproliferation initiatives would be assisted both domestically and internationally if the Commission were to terminate the GESMO proceedings,” “terminat[e] .. . staff reviews and hearings relating to recycle activities . . . den[y] . . . interim licensing of fuel cycle facilities, den[y] . . . interim licensing for use of mixed oxide fuel in reactors, except in small quantities for experimental purposes,” and publish the staff’s safeguards supplement.

¶415In re Mixed Oxide Fuel, 7 N.R.C. 711, 714-16 (1978) (emphasis added).

¶416The Commission also recognized that the President’s request was due substantial deference and added that there were strong indications of Congressional agreement:

In addition, it is significant that Congress as a body has not taken any action disagreeing with the President’s position on plutonium recycle in light water reactors.6 Over a year has passed since the President made the deferral of plutonium recycle a matter of national policy and no substantial Congressional opposition has appeared. Indeed, the Congress has in several instances supported the actions the President has taken to implement the Administration’s policy. The Department of Energy Act of 1978 — Civilian Applications, Pub.L.No. 95-238, 92 Stat. 47/ provides $13 million for various activities at the Barnwell Nuclear Fuels Plants related to alternative fuel cycle technologies and the nation’s non-proliferation objectives, but “none of the authorized funds may be used for operations of the plant to process spent fuel from reactors.”8 Sections 101(20), 106.9 Congress has also explicitly supported the President’s alternative fuel cycle studies in Section 105 of the Nuclear Non-Proliferation Act of 1978:

The President shall take immediate initiatives to invite all nuclear supplier and recipient nations to reevaluate all aspects of the nuclear fuel cycle, with emphasis on alternatives to an economy based on the separation of pure plutonium or the presence of high enriched uranium, methods to deal with spent fuel storage, and methods to improve the safeguards for existing nuclear technology .... 10

¶417In addition, Congress has strongly supported the non-proliferation goals of the Administration’s policy. Section 2 of the Nuclear Non-Proliferation Act of 1978 states the following policy:

The Congress finds and declares that the proliferation of nuclear explosive devices or of the direct capability to manufacture or otherwise acquire such devices poses a grave threat to the security interests of the United States and to continued international progress toward world peace and development. Recent events emphasize the urgency of this threat and the imperative need to increase the effectiveness of international safeguards and controls on peaceful nuclear activities to prevent proliferation. Accordingly, it is the policy of the United States to—

(a) actively pursue through international initiatives . . . the establishment of more effective international controls over the transfer and use of nuclear materials and equipment and nuclear technology for peaceful purposes in order to prevent proliferation....

¶418*509Moreover, Section 3 states that

It is the purpose of this Act to promote the policies set forth above by—

(a) establishing a more effective' framework for international cooperation ... to ensure that the worldwide development of peaceful nuclear activities and the export by any nation of nuclear materials and equipment and nuclear technology intended for use in peaceful nuclear activities do not contribute to proliferation . . .

¶419Finally, Section 2(c) strongly endorses the Treaty on the Non-Proliferation of Nuclear Weapons, July 1, 1968, T.I.A.S. No. 6839, the sole function of which is to halt the proliferation of nuclear weapons.11

¶4207 N.R.C. at 719-20.

¶421It is appropriate at this point to take judicial notice of a diametrically opposing point of view expressed by President Reagan:

Nuclear Energy Policy

Statement Announcing a Series of Policy Initiatives. October 8, 1981

A more abundant, affordable, and secure energy future for all Americans is a critical element of this administration’s economic recovery program. While homeowners and business firms have shown remarkable ingenuity and resourcefulness in meeting their energy needs at lower cost through conservation, it is evident that sustained economic growth over the decades ahead will require additional energy supplies. This is particularly true of electricity, which will supply an increasing share of our energy.

If we are to meet this need for new energy supplies, we must move rapidly to eliminate unnecessary government barriers to efficient utilization of our abundant, economical resources of coal and uranium. It is equally vital that the utilities — investor-owned, public, and coops — be able to develop new generating capacity that will permit them to supply their customers at the lowest cost, be it coal, nuclear, hydro, or new technologies such as fuel cells.

One of the best potential sources of new electrical energy supplies in the coming decades is nuclear power. The U.S. has developed a strong technological base in the production of electricity from nuclear energy. Unfortunately, the Federal Government has created a regulatory environment that is forcing many utilities to rule out nuclear power as a source of new generating capacity, even when their consumers may face unnecessarily high electric rates as a result. Nuclear power has become entangled in a morass of regulations that do not enhance safety but that do cause extensive licensing delays and economic uncertainty. Government has also failed in meeting its responsibilL ty to work with industry to develop an acceptable system for commercial waste disposal, which has further hampered nuclear power development.

To correct present government deficiencies and to enable nuclear power to make its essential contribution to our future energy needs, I am announcing today a series of policy initiatives:

(1) I am directing the Secretary of Energy to give immediate priority attention to recommending improvements in the nuclear regulatory and licensing process. I anticipate that the Chairman of the Nuclear Regulatory Commission will take steps to facilitate the licensing of plants under construction and those awaiting licenses. Consistent with public health and safety, we must remove unnecessary obstacles to deployment of the current generation of nuclear power reactors. The time involved to proceed from the planning stage to an operating license for new nuclear powerplants has more than doubled since the mid-1970’s and is presently some 10-14 years. This process must be streamlined, with the objective of shortening the time involved to 6-8 years, as is typical in some other countries.

(2) I am directing that government agencies proceed with the demonstration of breeder reactor technology, including completion of the Clinch River Breeder Reactor. This is essential to ensure our *510preparedness for longer-term nuclear power needs.

(3) I am lifting the indefinite ban which previous administrations placed on commercial reprocessing activities in the United States. In addition, we will pursue consistent, long-term policies concerning reprocessing of spent fuel from nuclear power reactors and eliminate regulatory impediments to commercial interest in this technology, while ensuring adequate safeguards.

It is important that the private sector take the lead in developing commercial reprocessing services. Thus I am also requesting the Director of the Office of Science and Technology Policy, working with the Secretary of Energy, to undertake a study of the feasibility of obtaining economical plutonium supplies for the Department of Energy by means of a competitive procurement. By encouraging private firms to supply fuel for the breeder program at a cost that does not exceed that of government-produced plutonium, we may be able to provide a stable market for private sector reprocessing and simultaneously reduce the funding needs of the U. S. breeder demonstration program.

(4) I am instructing the Secretary of Energy, working closely with industry and State governments, to proceed swiftly toward deployment of means of storing and disposing of commercial, high-level radioactive waste. We must take steps now to accomplish this objective and demonstrate to the public that problems associated with management of nuclear waste can be resolved.

(5) I recognize that some of the problems besetting the nuclear option are of a deep-seated nature and may not be quickly resolved. Therefore, I am directing the Secretary of Energy and the Director of the Office of Science and Technology Policy to meet with representatives from the universities, private industry, and the utilities, and requesting them to report to me on the obstacles which stand in the way of increased use of nuclear energy and the steps needed to overcome them in order to assure the continued availability of nuclear power to meet America’s future energy needs, not later than September 30, 1982.

Eliminating the regulatory problems that have burdened nuclear power will be of little use if the utility sector cannot raise the capital necessary to fund construction of new generating facilities. We have already taken significant steps to improve the climate for capital formation with the passage of my program for economic recovery. The tax bill contains substantial incentives designed to attract new capital into industry.

Safe commercial nuclear power can help meet America’s future energy needs. The policies and actions that I am announcing today will permit a revitalization of the U. S. industry’s efforts to develop nuclear power. In this way, native. American genius, not arbitrary Federal policy, will be free to provide for our energy future.

¶42217 Weekly Comp, of Pres. Doc. 1101-02 (Oct. 12, 1981).

¶423With this recent Presidential debate in mind, I turn to the possible consequences for this case of President Reagan’s announcement on October 8, 1981, which removed all restrictions on nuclear fuel reprocessing.

¶424B. The NRC Options

¶425It is, of course, obvious that the NRC has many decisions yet to make in relation to the back-end of the nuclear fuel cycle. It has yet to license a private corporation to build a retrievable surface storage facility, if, indeed, such will ever be built. It has yet to choose a site for its proposed long-term repository. And it has yet to license a commercial reprocessing facility, although it now appears that such will be licensed. Finally, the NRC has not decided whether the reactor fuel to be produced from the reprocessing of spent fuel will be fabricated from 1) uranium only into enriched uranium fuel, 2) uranium and plutonium into mixed oxide fuel, or 3) some other combination of elements not presently described.

¶426*511The NRC is seeking judicial sanction for the conclusion in the S-3 Tables that any releases that may be produced as a result of the exercise of any of these options can lawfully be termed “zero” or can lawfully be described as “umbrellaed” by the insignificant release figures set forth in the S-3 and S-3A Tables. I see no way by which we can in advance give such sanction consistent with the Administrative Procedure Act and the health and safety requirements of the Atomic Energy Act.

¶4271. The Uranium-only Recycle Option. The NRC may decide to adopt a uranium-only recycle plan. This plan contemplates the reprocessing of spent fuel rods and the production of highly enriched uranium. Nonetheless, the extraction and storage of the plutonium remains a problem. The NRC described the option when it promulgated the final version of Table S-3 in August 1979:

The fuel cycle was to be taken to include ... reprocessing of spent fuel for purposes other than recycle of plutonium, with follow-on interim and/or long-term storage or disposal of plutonium and wastes from reprocessing, with plutonium either separated from or included with the wastes.

¶42844 Fed.Reg. 45362, 45366 (Aug. 2, 1979) (footnote omitted).

¶429The NRC also envisions that

[t]he uranium would be converted to uranium hexafluoride for recycling at an enrichment plant. The plutonium, still containing about five percent of the fission products to deter diversion, would be converted to plutonium oxide and packaged for disposal in a Federal waste repository. The high-level liquid waste (HLLW) containing the bulk of the fission products, would be stored up to five years in tanks and then calcined and formed into glass for repository disposal.

¶430Id. at 45369.

¶431This option would, of course, reduce the hazards involved in extracting, storing and transporting plutonium dioxide. This option, however, raises by many degrees the uncertainties involved in the ultimate disposal of the wastes from the spent fuel rods. The remaining plutonium must be handled and guarded at the retrievable surface storage facility. Also, it must be shipped to the long-term waste disposal site and handled and guarded there until the repository is sealed.

¶432Once in the repository, the heat and bulk of the decaying plutonium would increase the thermal stresses on the geologic medium that constitutes the repository. U. S. Nuclear Regulatory Commission, Environmental Survey of the Reprocessing and Waste Management Portions of the LWR Fuel Cycle, (NUREG-0116) 4-103 (Oct. 1976). Finally, the existence of large amounts of plutonium buried underground would add to the chance that shifting geologic conditions would cause the inadvertent formation of a critical mass and consequent nuclear explosion. Id. at 4-103, 4-104.

¶433Continuation of the no-recycle option would, of course, raise somewhat similar problems.

¶4342. The Uranium-Plutonium Recycle Option. The possibility that the NRC might read an affirmance of Table S-3 as justification to proceed with the recycling of plutonium and the fabrication of mixed oxide fuel is particularly troubling. Initially, it is important to note that the NRC has deliberately excluded the risks of nuclear fuel diversion from Table S-3 because it believes those risks are negligible, not because it believes these risks are beyond the scope of this rulemaking. This has been evident throughout the course of the proceeding. For example, when the NRC published its assessment of the risks of the back-end of the light water reactor fuel cycle, NUREG0116, supra, public commentators questioned the exclusion of the risks of accident and sabotage from the interim version of Table S-3. The NRC answered that it excluded those risks because it thought they were negligible:

Comment (CEC B-139): It is unclear ‘whether sabotage impacts have been included in the revised Table S-3.

Response: The risks of sabotage are judged to be negligible and therefore no *512entry is given in Table 2.10 in NUREG0116. This judgment is based on the required protective measures of physical security, intrinsic protective features of containment systems required by regulations, and assessment of radiological consequences of given successful acts of sabotage. The NRC is conducting consequence studies of postulated sabotage events in all fuel-cycle facilities to assess current regulations and possible regulatory improvements as part of its continuing review of the adequacy of present safeguard measures.

¶435U. S. Nuclear Regulatory Commission, Public Comments and Task Force Responses Regarding the Environmental Survey of the Reprocessing and Waste Management Portions of the LWR Fuel Cycle 3-96 (March 1977) (NUREG-0216).11 After additional hearings on the proposed rule, the NRC Hearing Board expressed the same conclusion:

As a result of its analyses, the staff concluded that the impacts from accidents would be only a few per cent of the impacts from normal operation and did not include them in the values in Table S-3....

After considering the impacts of sabotage, the staff concluded that, overall, those impacts would be small in comparison with the impacts of normal operation and need not be explicitly included in Table S-3. This conclusion was based on the fact that acts of sabotage tend to resemble accidents. Measures provided to mitigate the effects of accidents should also mitigate the effects of sabotage. Moreover, the Commission now requires that substantial measures be taken to protect nuclear facilities from sabotage, including measures to protect against groups of highly motivated, well-trained saboteurs. We find the staffs conclusion reasonable.

¶436Conclusions and Recommendations of the Hearing Board Regarding the Environmental Effects of the Uranium Fuel Cycle, Docket No. RM 50-3 44-A5 (October 26, 1978); 4 J.A.S. 1466. The NRC adopted the recommendations of the Hearing Board when it promulgated the final version of Table S-3. See 44 Fed.Reg. 45362, 45367 (Aug. 2, 1979).12

¶437Second, the nuclear regulatory agencies of this country have always contemplated that plutonium recycling would be a part of any fuel reprocessing regime. At 10 C.F.R. § 70.4(m) (1981), which deals with the licensing of reprocessing facilities, we find this definition:

“Special nuclear material” means (1) plutonium, uranium 233, uranium enriched in the isotope 233 or in the isotope 235, and any other material which the Commission, pursuant to the provisions of section 51 of the act, determines to be special nuclear material ....

¶438And, the NRC’s new regulations dealing with the transportation of nuclear materials also envision the transportation of plutoni*513um.13 Section 73.2(aa) defines “[sjtrategic special nuclear material” thusly:

“Strategic special nuclear material” means uranium-235 (contained in uranium enriched to 20 percent or more in the U-235 isotope), uranium-233, or plutonium.

¶43910 C.F.R. § 73.2(aa) (1981).

¶440Accordingly, the NRC could read our affirmance of Table S-3 to support the conclusion that plutonium recycling can be accomplished with zero release and without endangering the public. The NRC believes that “the environmental impacts from reprocessing and related management activities are nearly identical for the recycling of uranium and plutonium and for the recycling of uranium only, as fuel in nuclear power reactors.” 46 Fed.Reg. 15154, 15161 (Mar. 4, 1981).14

¶441The section of this opinion which follows concerns possible employment of the plutonium option. The NRC may avoid this option because it is clearly the “worst case” in terms of hazards. Or it may adopt it because it appears to be the best option in terms of the economics of the nuclear power industry.

¶442C. The Plutonium Hazards

I fear that when the history of this century is written that the greatest debacle of our nation will be seen ... to be ... our creation of vast armadas of plutonium, whose safe containment will represent a major precondition for human survival, not for a few decades or hundreds of years, but for thousands of years more than human civilization has so far existed.

James D. Watson,

Nobel Laureate, Medicine

¶443On March 13,1975, Senator Stewart Symington addressed the United States Senate on “Controlling the Cancer of Nuclear Proliferation.” His concerns extended well beyond the boundaries of this country and the scope of this ease. The following paragraphs, however, serve to illustrate the nature of the problems generated by the recent Presidential decision to lift the prohibition against the NRC’s plan to reprocess nuclear waste so as to produce plutonium:

Only 10 to 20 pounds of plutonium is necessary for making an atomic bomb with the same destructive power as the one dropped on Hiroshima. Yet today, close to 90,000 pounds of plutonium have been produced by commercial nuclear power plants — not including amounts used for the nuclear weapons programs of the Big Powers.

Five years from now some half-million pounds of plutonium may be commercially available throughout the world. As the amount of plutonium grows internationally so does the risk of its diversion from peaceful uses to weapons-development programs.

¶444121 Cong.Rec. 6437 (1975).

¶445In present posture, this case requires us to compare the NRC’s flat assurance of zero or insignificant release of effluents as stated in Table S-3 with the incredible risks involved in transporting large quantities of plutonium all over the United States.

¶446Plutonium is one of the most deadly substances known to humankind. It is toxic to human beings if a microscopic particle is breathed into the lungs.

A small quantity of Plutonium-239 smoke deposited in the lung — about one ten-thousandths of an ounce, would kill a person through radiological destruction of lung tissue. A quantity smaller than one one-millionth of an ounce would give rise to a substantial risk of lung cancer . . . Plutonium-239 ... is at least 20,000 times *514more toxic than cobra venom or potassium cyanide and ten times more toxic than heroin or modern nerve gas.

¶447Ford Foundation Energy Policy Project, A Time to Choose 210 (1974).

¶448After reprocessing, plutonium is reduced to oxide powders for shipment to fuel fabrication plants:

NRC regulations prohibit the shipment of plutonium compounds, apart from small quantities, in liquid form. Consequently, the plutonium is converted into the solid dioxide [Pu02] prior to shipment. Plutonium Oxalate is generally precipitated from the nitrate solution; the oxalate is separated, dried and calcined to form the dioxide. The product is ground and screened to yield a powder of the desired size.

¶449S. Glasstone & W. Jordan, Nuclear Power and Its Environmental Effects 234 (1980).

¶450This powder would be extremely dangerous if dispersed into the air as it could be by accident, theft or sabotage:

Both in storage and in transit, separated plutonium requires the most careful .. . measures . .. against theft by non-state actors. Owing to the serious inhalation hazard of powdered Pu02, currently the form in which most nonmilitary stocks are held, equally strict measures for protection of public health and safety are . . . required. These precautions . . . are to be applied from the time the material emerges from the reprocessing plant — at least until ... it is fabricated into reload fuel assemblies, thereby rendering accounting easier and theft more difficult.

¶451G. I. Rochlin, Plutonium, Power and Politics 90 (1979).

¶452Indeed, even the fabricated mixed oxide fuel would be an attractive target for terrorists. The Nuclear Energy Policy Study Group explained why:

Shipments of fresh mixed oxide fuel for the yearly reloading of a single reactor would contain enough plutonium for fifty nuclear weapons. Separation of plutonium ... would be much easier than from irradiated fuel, involving only simple chemical operations and little radiation hazard.

¶453Nuclear Energy Policy Study Group, Nuclear Power: Issues & Choices 331 (1977) (hereafter NEPSG).

¶454The Study Group pointed out the general, worldwide increase in terrorism over the last decade:

The past few years have seen an upsurge in the size, sophistication and capabilities of terrorist groups around the world. Terrorist activities offer strongly motivated political or dissident groups a way to dramatize their causes and influence their adversaries .. . the worldwide development of civilian nuclear power provides additional opportunities for terrorists — whether revolutionaries, nationalists, dissidents or criminally motivated— to employ nuclear energy as a weapon... .

Terrorists might choose the nuclear industry as a target to exploit the mystique that surrounds nuclear weapons. The threat of nuclear terrorism may be used to extort money, secure the release of prisoners or publicize a particular cause.

¶455Id. at 301.

¶456The simplest form of sabotage would probably consist of blowing up a truck that was transporting plutonium from the reprocessing plant to a fuel fabrication plant or nuclear reactor. A high explosive charge fracturing the shipping container and discharging the oxide powder into the air could occasion disaster to any area downwind.

¶457In addition, plutonium is highly explosive and extremely powerful. It has been estimated that 10 pounds of plutonium fashioned into a bomb could kill 100,000 people in a densely populated city. It has also been estimated by one knowledgeable expert that many thousands of persons in the United States have the knowledge required to design a workable bomb.

¶458With only presently-licensed nuclear reactors taken into account, the NRC’s plan for reprocessing nuclear waste would produce 200-300 kilograms (440-660 lbs.) of plutoni*515um from each of 71 reactors, or over 35,000 pounds of this hazardous substance.

¶459On this score the Nuclear Energy Policy Group Study said:

[T]he weakest link in security would be transportation .... The [1973] regulatory changes [to reduce the possibility of employee diversion] did not eliminate the possibility that a small armed group could successfully hold up a truck and hijack its load of nuclear materials .... Transport procedures are not vastly different than those employed by armored ear companies and other carriers that ship high-value cargo. Some criminal and terrorist groups have already demonstrated capabilities to defeat such precautions.

¶460Id. at 304.

¶461Lovins, Lovins & Ross summarized the present problems of preventing plutonium diversion:

Political arrangements for safeguards must rest on technical measures for materials accounting and for physical security. The former measures are so imprecise and post hoc that they cannot, even in principle, provide reasonable assurance that many bombs’ worth of plutonium per year are not being removed from a good-sized reprocessing plant. Primary reliance must therefore be placed on physical security measures to limit access . . . These measures must forestall well equipped groups perhaps including senior insiders acting in concert with the host government or a faction of it. Even modestly effective measures would be costly, fallible and intrusive.

¶462Lovins, Lovins & Ross, Nuclear Power and Nuclear Bombs 58 Foreign Affairs 1137, 1145 (Summer 1980).

¶463The Nuclear Energy Policy Study Group summed up, “If plutonium and highly enriched uranium become increasingly available, the route to national or subnational explosives capabilities will become easier and quicker and safeguards will lose much of their ability to provide reassurance.” NEPSG, supra at 294.

¶464Commentary on these hazards could be extended indefinitely, since the literature concerning the hazards of plutonium is almost endless.

¶465If this were a wholly peaceful world, or if ours were a wholly peaceful country, the NRC’s plan to recycle plutonium and fabricate and burn it as a fuel would be subject to much less objection. In fact, however, the United States confronts many hostile powers, some with vast wealth and the consequent ability to train and arm desperadoes or to bribe and corrupt personnel connected with either private or government aspects of the nuclear cycle. In addition, past history (and in particular the last two decades) teaches that domestic tranquility is a constitutional goal rather than a reality in our land. Organized crime as we know it in our country is capable of hijacking a truck with armed guards, and terrorist groups capable of stopping and robbing Brinks trucks of millions of dollars have demonstrated a somewhat like capability. See NEPSG, supra at 304.

¶466The routine use of plutonium for nuclear power under the Commission’s present plans will call for a private corporation to reprocess the spent fuel rods from all nuclear reactors, thus producing plutonium. By Commission regulation, that corporation is required to organize a private army larger than has ever existed in this country and to deploy it at the reprocessing plant and on U. S. highways all over the land. See 10 C.F.R. § 73.25 (1981). Nevertheless, under the Commission’s present plans, it will be impossible to guarantee the security of plutonium shipments from an intelligently organized surprise attack by substantial forces on a lonely stretch of highway in a remote area. Under the Commission’s present plans, the ultimate reliance is upon a call to local law enforcement. See 10 C.F.R. § 73.26(c)(2)(iii)(A), (i)(6) (1981). In the event of attack at a lonely milepost, the call might produce one deputy sheriff. Protecting plutonium shipments is a task appropriate for the military forces of the United States. No such authorization has been sought from or considered by Congress.

¶467*516I assume that the theft by stealth or force of sufficient plutonium to fabricate a bomb and its subsequent employment by threats or fact of explosion would constitute a “release.” In my view, the threat of such a “release” of plutonium if it is fabricated, stored and shipped all over the nation, is anything but “insignificant.” The NCR’s finding to the contrary constitutes “a clear error of judgment.” See Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 416, 91 S.Ct. 814, 823, 28 L.Ed.2d 136 (1971). As indicated earlier, I therefore join in holding the affected portions of Table S-3 to be arbitrary and capricious.

¶468The fundamental law that launched this nation on the road to peaceful use of nuclear power was the Atomic Energy Act of 1946, ch. 724, 60 Stat. 755 (1946). That Act was superseded by the Atomic Energy Act of 1954, ch. 1073, 68 Stat. 921 (1954) (codified in 42 U.S.C. § 2011 et seq.). The 1954 Act repeatedly requires the “protect[ion] of the health and safety of the public.” 42 U.S.C. §§ 2012(d), (e), 2133(b), 2232(a) (1976); see id.§ 2133(d).

¶469After much acquaintance with this case, I have come to believe that Table S-3, inasmuch as it requires licensing boards to accept that only insignificant releases will result from transporting plutonium all over the nation to 71 (potentially 190) reactors is “otherwise not in accordance with law.”

¶470COST

¶471Appellants New York and Wisconsin contend that the figure of 10% of construction costs per nuclear reactor determined by the NRC as the cost of nuclear waste disposal is arbitrary and capricious. I agree.

¶472As I understand this record, the 10% of cost (building and operating) per nuclear reactor represents the Commission’s determination of the economic cost of all nuclear waste disposal. Thus, it underpins the Commission’s adoption of the S-3 Tables and is properly before this panel for decision at this time.

¶473This record indicates that the NRC now assumes that all nuclear waste is to be under the guardianship of the federal government practically in perpetuity and that all nuclear waste costs above the 10% referred to above for each reactor will be borne by the United States. Under ordinary standards of accountability (absent subsidy determined by law), appropriate charges for maintaining facilities owned and operated by government for private industry would be determined and charged back to the private industry making use of them. The cost of maintenance, surveillance and guarding the public from toxic waste at all such facilities will continue from somewhere between 10,000 and 250,-000 years. The currently estimated life of each reactor is 30 years. The nuclear power industry may not survive its problems. Its waste will, for all practical purposes, survive forever. This policy decision potentially involves an open-ended subsidy of great dimension. Constitutionally, it can only be made as a matter of legislation by Congress and the President. It certainly should not be made sub silentio by an administrative agency and routinely endorsed by the federal courts.

¶474I dissent from my colleagues’ treatment of the economic issue. I would remand the issue concerning the economic feasibility of the S-3 Tables to the Commission for further consideration. Public discussion of these costs at licensing hearings should not be terminated until much more knowledge about them has been developed.

¶475Outline

¶476I. Analysis----------------------------- 517

¶477II. Background _______ 518

¶478A. The Challenged Rules_______________ 518

¶479B. Vermont Yankee I__________________ 519

¶480C. Vermont Yankee II_________________ 520

¶481III. Our Task on Remand____________________ 524

¶482A. The Agency’s Decision ______________ 524

¶483B. Contemporaneous Explanation________ 525

¶4841. The Commission’s Purpose________ 525

¶4852. The Commission’s Methodology____528

¶4863. The Commission’s Conclusions______529

¶487C. The Appropriate Standard of Review___530

¶488D. The Standard of Review Applied to the

¶489Agency’s Decision__________________ 533

¶4901. “Scope of Authority”____________ 533

¶4912. “Observance of Procedure"_______535

¶4923. “Reasoned Decisionmaking”_______537

¶493IV. Living With Uncertainty _______________ 540

¶494V. Conclusion---------------------------545

¶515*517WILKEY, Circuit Judge,

¶516dissenting:

¶517In Greater Boston Television Corp. v. FCC1the late Judge Leventhal first enunciated what has come to be known as the “hard look” doctrine for judicial review of agency action.2 When today’s case first came to this court (Vermont Yankee I), Judge Bazelon upped the ante by endorsing the notion of a “good, hard look.”3 Now, notwithstanding clear directions to the contrary from the Supreme Court (in Vermont Yankee II),4Judge Bazelon has applied a standard which is best described as requiring “too hard a look.” If there was ever a doubt prior to today, it is now clear that this court is committed to an assumed role as high public protector of all that is good from perceived evils of the nuclear age.

¶518In his lengthy opinion today (Vermont Yankee III) Judge Bazelon adapts to a new heading an approach unanimously rejected by the Supreme Court in Vermont Yankee II and steps boldly into the arena of nuclear regulation to vacate all of the NRC’s original, interim, and final fuel cycle rules — the product of nearly a decade of agency and judicial proceedings and an administrative record of thousands of pages in length. He justifies this action on a conclusion that the Commission somehow violated NEPA and the APA by adopting a generic table embodying a prediction that nuclear power plant wastes can someday be safely stored.

¶519Judge Bazelon’s majority opinion has braided from NEPA, the APA, and his own perceptions of public good a novel standard of substantive and procedural scrutiny of NRC activity which we as a court are unauthorized to create and ill-equipped to manage. It has ignored the Supreme Court’s unequivocal mandate that we limit our examination in this matter to the administrative record to determine only whether the NRC’s rule was “arbitrary and capricious within the meaning of § 10(e) of the Administrative Procedure Act, 5 U.S.C. § 706.”5 On the record before us, which has been supplemented extensively since Vermont Yankee II, I cannot say that under the appropriate standard the rule fails. Accordingly, I would affirm.6

¶520I. ANALYSIS

¶521The cases before us today represent the latest chapter in perhaps the most celebrated administrative litigation of our time. Although the procedural backdrop of the litigation, adequately rehearsed in Judge Bazelon’s opinion,7 is extraordinarily complex, I believe the analysis and resolution of the central issues are comparatively simple.

¶522That analysis must begin with a review of the case history, culminating in the unanimous directive given us by the Supreme Court in Vermont Yankee II. Both the holdings and the language of that opinion, essentially endorsing Judge Tamm’s original concurrence in Vermont Yankee I,8 clarify the appropriate standard for our review of the informal rulemaking challenged here. When we examine the agency’s rule-making under that standard, two further *518points become clear. First, the agency acted well within the scope of its broad authority by choosing to consider the issue of long-term risks and uncertainties from radioactive waste disposal genetically, rather than in a series of repetitive individual power plant licensings. Second, contrary to the majority’s joint assertions, the agency did not act arbitrarily and capriciously or “not in accordance with law” by concluding that licensing boards need not factor uncertainties into their environmental analyses, but, 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”: namely, that sites can be found and the technology developed effectively to isolate radioactive waste from the biosphere.9

¶523These conclusions are not only compelled by a careful review of the extensively supplemented record on appeal; they are totally consistent with all of the evidence reviewed in Judge Bazelon’s opinion. That record clearly reveals that the Commission has fulfilled its procedural obligations under § 102(2)(C) of NEPA10 and the Administrative Procedure Act,11 has taken the requisite “hard look” at the waste storage question, and has supported its final rule by “reasoned decisionmaking.” This court may require no more.

¶524We easily resolve this appeal if we recognize the obvious — we live in a world of risk, uncertainty, and rapid technological change.

¶525We not only expect, we demand, expert agencies charged with broad statutory discretion to make predictions en route to factual, technical, and policy judgments. “Where existing methodology or research in a new area of regulation is deficient, the agency necessarily enjoys broad discretion to attempt to formulate a solution to the best of its ability on the basis of available information.” 12 So long as the agency adequately observes statutory procedures, gives close scrutiny to all relevant considerations, and engages in reasoned decision-making, it is not our job to substitute our judgment for the agency’s to reach what we perceive to be the best or correct result. Yet this is precisely what the majority has accomplished in this case.

¶526II. BACKGROUND

¶527A. The Challenged Rules

¶528The rules at issue here13 resulted from an informal, “generic” rulemaking instituted by the NRC in November 1972 under 5 U.S.C. § 553 of the Administrative Procedure Act.14 This proceeding, like a number of generic rulemakings noticed by the Commission since 1972,15 was intended primarily to provide information for future adjudications in licensing proceedings. The product of the rulemaking was a table of numerical values (Table S-3), representing the incremental environmental effects associated with the uranium fuel cycle of one addition*519al light water power reactor.16 Individual licensing boards, in turn, were allowed to factor those representative values into the cost-benefit analysis for each proposed facility as part of the detailed Environmental Impact Statement (EIS) required by § 102(2)(C) of NEPA.17

¶529Like all generic rulemakings, the proceeding here was instituted to further the goals of administrative efficiency, public participation, and uniformity in agency adjudications.18 The rulemaking permitted the agency to consider and settle in one proceeding a number of issues of fact or policy common to a large number of licensing hearings. Without the informal rulemaking, “generic” issues would have been reopened at each proceeding before individual licensing boards. This not only would have required, in proceeding after proceeding, an inefficient presentation of identical and repetitive evidence bearing on matters not truly “local” to the plant proposed for license,19 but likely would have resulted in inconsistent adjudications.

¶530B. Vermont Yankee I

¶531When this case first came to our court, environmentalist petitioners challenged Table S-3 on the grounds that its values “ex-presse[d] in numerical terms the conclusion that the environmental effects of the fuel cycle, including [nuclear power] waste disposal, are insubstantial.”20 Judge Bazelon’s opinion for the court set aside those portions of the rule pertaining to the issues of high-level waste disposal and waste reprocessing.21 At the outset the panel majority held, under § 102(2)(C) of NEPA, that “absent effective generic proceedings to consider [long-term waste disposal] issues, they must be dealt with in individual licensing proceedings.”22 Judge Bazelon’s opinion for the panel then went on to find the agency’s generic proceedings “ineffective” for two interrelated reasons: because the agency’s procedures were inadequate to “ventilate” thoroughly the waste fuel disposal issues, and because the agency’s record was inadequate to support its rule.23

¶532*520Thus, the issues were relegated to individual adjudication.

¶533Judge Tamm, concurring in the result, joined only the second of the court’s two grounds, finding that “the inadequacy of the record demands that we remand this case to the Commission -in order to ensure that it has taken a hard look at the waste storage issue.”24 Challenging Judge Bazelon’s first ground of decision, Judge Tamm noted that “the deficiency is not with the type of proceeding below, but with the completeness of the record generated.”25 He concluded,

The appropriate remedy at this point is not to impose ad hoc procedural requirements in an attempt to raise the level of petitioners’ participation, already adequate under [5 U.S.C.] section 553, but to remand for . . . the documentation which the majority finds so conspicuously lacking. The Commission should be able to supply the court with a statement of the methods by which its staff arrived at the figures embodied in Table S-3 and by which [the NRC Waste Management Division Director] concluded that the waste storage problem is already technologically and economically soluble. If it cannot, we will have no choice but to invalidate the Commission’s rule under the “arbitrary, capricious” standard; if it can, we should defer to the administrative weighing of risks and benefits of additional reactors.26

¶534C. Vermont Yankee II

¶535The Supreme Court unanimously reversed the panel opinion.27 The united Court, speaking through Justice Rehnquist, resoundingly rejected the first of the panel’s decisional grounds:

[N]othing in the APA, NEPA, the circumstances of this case, the nature of the issues being considered, past agency practice, or the statutory mandate under which the Commission operates permitted the [circuit] court to review and overturn the rulemaking proceeding on the basis of the procedural devices employed (or not employed) by the Commission so long as the Commission employed at least the statutory minima, a matter about which there is no doubt in this case.28

¶536The Court did not, however, reverse this court’s second finding, concurred in by Judge Tamm. Instead, it remanded that question to us with the following directive:

There remains, of course, the question of whether the challenged rule finds sufficient justification in the administrative proceedings that it should be upheld by the reviewing court. Judge Tamm, concurring in the result reached by the majority of the Court of Appeals, thought that it did not. There are also intimations in the majority opinion which suggest that the judges who joined it likewise may have thought the administrative proceedings an insufficient basis upon which to predicate the rule in ques*521tion. We accordingly remand so that the Court of Appeals may review the rule as the Administrative Procedure Act provides. We have made it abundantly clear before that when there is a contemporaneous explanation of the agency decision, the validity of that action must “stand or fall on the propriety of that finding, judged, of course, by the appropriate standard of review. If that finding is not sustainable on the administrative record made, then the Comptroller’s decision must be vacated and the matter remanded to him for further consideration.” Camp v. Pitts, 411 U.S. 138, 143 [93 S.Ct. 1241, 1244, 36 L.Ed.2d 106] (1973). See also SEC v. Chenery Corp., 318 U.S. 80 [63 S.Ct. 454, 87 L.Ed. 626] (1943). The court should engage in this kind of review and not stray beyond the judicial province to explore the procedural format or to impose upon the agency its own notion of which procedures are “best” or most likely to further some vague, undefined public good.29

¶537The Vermont Yankee II Court buttressed its explicit mandate with four observations of major significance to our review on remand. First, the Court reiterated the broad scope of NRC authority to deal with fuel cycle issues by rulemaking.30 Second, the Court declared that this court had “fundamentally misconceivefd] the nature of the standard for judicial review of an agency rule.”31

[Because] informal rulemaking need not be based solely on the transcript of a hearing held before an agency .. . the adequacy of the “record” in this type of proceeding is not correlated directly to the type of procedural devices employed, but rather turns on whether the agency has followed the statutory mandate of the Administrative Procedure Act or other relevant statutes32

¶538The Court’s third observation, particularly important for our purposes today, emphasized the limited scope of our power to review NRC rulemaking under NEPA. Justice Rehnquist stated in no uncertain terms that a reviewing court’s already-limited power to review the substance of agency decisions is not significantly supplemented by the broadly stated environmental mandate found in § 101 of NEPA.33 In *522Calvert Cliffs’ Coordinating Comm. v. AEC,34this court had held that § 101 imposes substantive restraints on agency actions, thus obliging courts to review agency decisions on the merits to ensure their consistency with the goals of NEPA.35 In Vermont Yankee II the Court acknowledged that while “NEPA does set forth significant substantive goals for the Nation, ... its mandate to the agencies is essentially procedural.”36In Stryckers’ Bay Neighborhood Council v. Karlen,37the Court elaborated on that statement:

Vermont Yankee cuts sharply against the Court of Appeals’ conclusion that an agency, in selecting a course of action, must elevate environmental concerns over other appropriate considerations. On the contrary, once an agency has made a decision subject to NEPA’s procedural requirements, the only role for a court is to insure that the agency has considered the environmental consequences ; it cannot “ ‘interject itself within the area of discretion of the executive as to the choice of the action to be taken.’ ”38

¶539Furthermore, the Vermont Yankee II Court explicitly rejected Judge Bazelon’s view that NEPA authorizes courts to require agencies to “develop new procedures to accomplish the innovative task of implementing NEPA through rulemaking:”39

We have before observed that “NEPA does not repeal by implication any other statute.” ... In fact, just two Terms ago, we emphasized that the only procedural requirements imposed by NEPA are those stated in the plain language of the Act. . . . Thus, it is clear NEPA cannot serve as a basis for a substantial revision of the carefully constructed procedural specifications of the APA.40

¶540Thus, after Vermont Yankee II, reviewing courts must not only limit their substantive review of agency action to the appropriate standards under the APA, they must take pains in their procedural review to avoid imposing requirements in excess of the “statutory minima” or extending their scrutiny beyond the “plain language” of § 102.

¶541Vermont Yankee II’s fourth major pronouncement arose from its discussion of a consolidated case. Addressing Consumers Power Co. v. Aeschliman,41which presented identical fuel cycle issues in the licensing context, the Vermont Yankee II Court reiterated both the breadth of NRC statutory authority and the limited “role of a court in reviewing the sufficiency of an agency’s *523consideration of environmental factors” under NEPA.42 The Court expressly recognized that § 102(2)(C) requires responsible agency officials to include in each EIS “a detailed statement ... on ... alternatives” to the proposed federal action43 and that NEPA obliges agencies to consider “every significant aspect of the environmental impact” of the action.44 Nevertheless, it refused to read those NEPA requirements as placing on the agency the burden of justifying every decision not to consider a highly unlikely alternative to a given action. The initial burden of establishing that an alternative is sufficiently material to require agency consideration, the Court suggested, properly rests with the challenger to the agency action.45 Furthermore, the Court reasoned, even when the challenger has met that burden, the agency’s subsequent duty to consider and explore little-known technological alternatives must necessarily be bounded by two practical constraints: the feasibility of those alternatives46 and the extent of information about them currently available.47

¶542In short, the Vermont Yankee II Court’s discussion of Consumers Power confirmed a view this court has stated several times: that NEPA necessarily allows agencies some flexibility in determining the contents of their environmental impact statements in situations where uncertainty is abundant, technological alternatives are still developing, and much crucial information remains unavailable.48 In such circumstances, as *524Judge Wright noted in Scientists’ Institute for Public Information v. AEC,49 “NEPA is not a paper tiger, but neither is it a straitjacket.”50

¶543Vermont Yankee II closed with the unambiguous command that courts should not employ judicial review of NRC action to encroach on fundamental policy choices in the nuclear power arena:

Nuclear energy may some day be a cheap, safe source of power or it may not. But Congress has made a choice to at least try nuclear energy, establishing a reasonable review process in which courts are to play only a limited role. The fundamental policy questions appropriately resolved in Congress and in the state legislatures are not subject to re-examination in the federal courts under the guise of judicial review of agency action. Time may prove wrong the decision to develop nuclear energy, but it is Congress or the States within their appropriate agencies which must eventually make that judgment. In the meantime courts should perform their appointed function.51

¶544III. OUR TASK ON REMAND

¶545The majority has deviated from a clearly presented path — charted by the Supreme Court itself — to lead this court again on a confusing and unauthorized incursion into a policymaking area reserved by Congress to the NRC. I cannot participate in this trespass.

¶546The Supreme Court’s explicit directive in Vermont Yankee II was that we first, clarify the nature of the agency decision under challenge; second, seek a “contemporaneous explanation ” of that decision; and third, judge the “propriety of that finding by the appropriate standard of review."52 A conclusion that the agency’s finding was sustainable on the administrative record would effectively end our inquiry.

¶547A. The Agency’s Decision

¶548The primary NRC choice still under review is the agency’s decision to promulgate the final rule based on the factual record before it. As Judge Tamm noted in his original concurrence in Vermont Yankee I, that type of rule “encompass[es] both factual determinations and policy choices.”53 Although the line separating fact and policy has never been hard and fast,54 we have often employed the distinction to calibrate the intensity with which we scrutinize an agency’s contemporaneous explanation of its decisions.55 Judge Tamm explained in Vermont Yankee I how the distinction has been commonly employed:

This court has also distinguished between factual determinations and policy choices more peculiarly within the expertise of *525the administrative agency. In the former case, we commonly have insisted upon sufficient attention to the facts to enable the reviewing court to ascertain the underlying rationality of the resultant regulations. ... In contrast, “[wjhere ... the regulations turn on choices of policy, on an assessment of risks, or on predictions dealing with matters on the frontiers of scientific knowledge, we will demand adequate reasons and explanations, but not ‘findings’ of the sort familiar from the world of adjudication.”56

¶549Contrary to intimations in the majority opinion57 none of the specific figures in Table S-3 were intended to reflect factual certainties.58 Rather, they were a series of estimated fuel cycle impacts based on agency predictions, educated guesses, and assumptions about the future, combined with quantitative analysis. As such, they fell squarely into the gray area between “fact” and “policy.” When such predictions are asserted as facts based on hard data, with all uncertainties and assumptions underlying them undisclosed, they deserve to be scrutinized as factual determinations. When they are asserted as qualitative risk assessments, however, validly based on agency expertise and the best available information, with underlying uncertainties and assumptions fully exposed, they deserve the greater deference given to agency policy choices.59 It is impossible to determine when predictions deserve the deference given policy choices and when they deserve the closer scrutiny given facts without assessing the purposes for which the predictions were made, the methodology by which they were developed, and the conclusions they served to support. For this information we must turn to the agency’s contemporaneous explanation, as the Supreme Court directed.

¶550B. Contemporaneous Explanation

¶5511. The Commission’s Purpose

¶552A 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 pur*526pose 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.

¶553The 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 *527intent 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

¶554Accordingly, 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

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

¶555Because 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 *528important aspects of the fuel cycle not addressed by the table.”66

¶556In 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 rule-making “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

¶557The 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:

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

¶558Aware 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.

¶5592. The Commission’s Methodology

¶560To 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 *529deposit 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

¶561The 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

¶5623. The Commission’s Conclusions

¶563The 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 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

¶564While 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

¶565Then 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”:

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 rule-making 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 as*530sumption 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

¶566Based 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 conelusions 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

¶567C. The Appropriate Standard of Review

¶568The agency action challenged here was an informal generic rulemaking. Under 5 U.S.C. § 706 of the Administrative Procedure Act, which governs judicial review of agency action, the well-established standard for our review of that action is whether the agency decision was “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.”88 That is the stan*531dard which Judge Tamm expected,89 and the Supreme Court directed90 us to use in evaluating the agency’s decision. Although it is also the standard which the majority purports to use, a careful reading of their opinion reveals that they have paid it lip service only. The approach actually adopted results in a judgment-substituting analysis which not only exceeds the limits of proper judicial review but which denies the presumption of regularity normally accorded an agency’s action.

¶569In Citizens to Preserve Overton Park v. Volpe,91 the Supreme Court described the appropriate focus of judicial review under § 706 by essentially consolidating the various overlapping standards listed in § 706(2)(A), (B), (C) and (D) under a single heading — “arbitrary, capricious, or an abuse of discretion” — under which it distinguished three necessary inquiries.92 First, the Court held, a reviewing court is “required to decide whether the [agency] acted within the scope of [its] authority. This determination naturally begins with a delineation of the scope of the [agency’s] authority and discretion.” 93 Implicit in this determination is an assessment of the range of choices delegated by Congress to the agency’s discretion and a decision whether the agency’s action can reasonably be said to fall within that range of choices.

¶570A second directive found in Overton Park was that reviewing courts carefully determine whether the agency’s actions have followed the “necessary procedural requirements.” 94 In this case, those requirements are found in both the relatively loose notice-and-comment procedures of § 553 of the Administrative Procedure Act95 and the disclosure requirements of NEPA.96

¶571Finally, Overton Park held that the court must engage in a limited substantive review of the agency’s actual decision. Even if an agency has made a decision Congress has empowered it to make, has accorded the parties “administrative due process” by observing all required procedures, and has supported its decision with some evidence,97*532the court must still assure itself that the agency based its result on a sustainable rationale — i.e., that the agency demonstrated a logical connection between the evidence it adduced and the conclusion it reached.98 In the words of Overton Park, § 706

requires a finding that the actual choice made was not “arbitrary, capricious, an abuse of discretion, or otherwise not in accordance with law.” To make this finding the court must consider whether the decision was based on a consideration of relevant factors and whether there has been a clear error of judgment. Although this inquiry into the facts is to be searching and careful, the ultimate standard of review is a narrow one. The court is not empowered to substitute its judgment for that of the agency.99

¶572In recent years this court has elevated the Overton Park notion of limited substantive review of agency decisions in critical cases into a somewhat ill-defined doctrine commonly called the “hard look” doctrine of judicial review.100 While the original concept, pioneered by the late Judge Leventhal, was that agencies should take a “hard look” at complicated technological decisions with serious environmental, health, and safety consequences,101 later decisions have read the doctrine to require courts to take a hard look to ensure that agencies have taken a hard look.102 Not surprisingly, the proper level and nature of judicial, as opposed to agency, scrutiny of informal rule-makings remains a subject of intense judicial 103 and scholarly104 debate after Vermont Yankee II. Nevertheless, whether expressed in “hard look” terms or not, the limited substantive review endorsed by Overton Park addresses legitimate concerns. As Judge Wald recently noted in National Lime Ass’n v. EPA :105

Collectively, these concerns have sometimes been expressed as a need for “reasoned decision-making” and sometimes as a need for adequate “methodology.” However expressed, these more substantive concerns have been coupled with a *533requirement that assumptions be stated, that process be revealed, that the rejection of alternate theories or abandonment of alternate courses of action be explained and that the rationale for the ultimate decision be set forth in a manner which permits the public to exercise its statutory prerogative of comment and the courts to exercise their statutory responsibility upon review.106

¶573D. The Standard of Review Applied to the Agency’s Decision

¶5741. “Scope of Authority”

¶575As this court has held time and again,107 the Atomic Energy Act’s statutory delegation of authority to the NRC is unusually broad. Judge McGowan noted in Siegel v. AEC,

[In the AEA] Congress ... enact[ed] a regulatory scheme which is virtually unique in the degree to which broad responsibility is reposed in the administering agency, free of close prescription in its charter as to how it shall proceed in achieving the statutory objectives.108

¶576The Vermont Yankee II Court was emphatic in its reaffirmation of the NRC’s broad authority to deal with fuel cycle issues by rulemaking.109Necessarily encompassed within that rulemaking authority is the power to treat certain factual and policy issues generically.110 And the power to treat those issues generically itself must include the discretion to incorporate a certain amount of prediction into the final rule’s table of release values.111

¶577The NRC has confidently — and to my mind, correctly — determined that the decision to promulgate a rule in the form of a noncomprehensive table of predicted release values — whose significance for human lives is subject to discussion in individual licensing proceedings, whose accuracy is subject to update and refinement, and whose uncertainties are candidly acknowledged — lies well within the authority granted to it by Congress. Under the Supreme Court’s directive in Power Reactor Development Co. v. International Union of Electrical, Radio, & Machine Workers,112we are obliged to *534give that determination considerable deference.113

¶578In accordance with Power Reactor, this court has frequently held that where agency rules, such as the one here, are based on “choices of policy, . . . assessment of risks, or . . . predictions dealing with matters on the frontiers of knowledge” the agency has the authority to promulgate such rules, so long as they are based on such facts as are available and on rational predictions about how currently unanswerable questions will someday be answered.114 Thus, an agency “may apply [its] expertise to draw conclusions from suspected, but not completely substantiated, relationships between facts, from trends among facts, from theoretical projections from imperfect data, from probative preliminary data not yet certifiable as ‘fact,’ and the like.” 115 The agency does not merely have the power to promulgate a rule based on such predictions; it has a duty to do so as long as it exercises that authority “subject to the restraints of reasonableness, and does not open the door to “‘crystal ball” inquiry.’”116

¶579Judge Bazelon does not openly challenge the broad powers exercised generally by the NRC under the authority of the AEA, but he does not expressly recognize them, either. And it is obvious that the deference due to the Commission has not tempered the majority’s determination to find some error in the Table S-3 Rule. Here, as in Vermont Yankee I, it is a NEPA-based standard of Judge Bazelon’s manufacture, bootstrapped into the APA, which provides the means to the “desired” end. Contrary to holdings in this court recognizing the flexibility of agency duties under NEPA in the face of uncertainties,117 the majority has found in its construction of NEPA procedural and substantive standards by which to limit the NRC’s broad substantive discretion. It holds that the Commission’s action failed to meet NEPA’s mandates and that it *535was taken without proper consideration of all relevant factors. These relate more to Overton Park’s second and third inquiries than to the general question of authority.

¶5802. “Observance of Procedure’’

¶581The Vermont Yankee II Court confirmed our duty to conduct a limited procedural review of the Commission’s activity by restating the second aspect of the Overton Park analysis: “Of course, the [circuit] court [on remand] must determine whether the agency complied with the procedures mandated by the relevant statutes.”118 It warned, however, that we “should ... not stray beyond the judicial province to explore the procedural format or to impose upon the agency its own notion of which procedures are ‘best’ or most likely to further some vague, undefined public good.” 119 Judge Bazelon has effectively ignored this warning, however, and once again disguises a strict substantive review under NEPA in a fundamentally procedural rubric. While our scrutiny for compliance with NEPA’s procedural mandate may be, as Judge Bazelon asserts, a close one, it must not extend across the line separating the Commission’s procedural duty from substantive determinations and policymaking. The latter category of action is properly reviewable only under the “arbitrary and capricious” standard. Thus, although I agree with the majority opinion that NEPA’s requirements are among those providing an overall procedural standard for the Commission’s action, I disagree with Judge Bazelon’s assertions of what those requirements are and how they are to be applied in the rulemaking context.

¶582The Supreme Court emphasized in Vermont Yankee II that while “NEPA does set forth significant goals for the Nation, . .. its mandate to the agencies is essentially procedural,”120 and that “the only procedural requirements imposed by NEPA are those stated in the plain language of the Act.”121 The plain language of NEPA, to the extent relied upon by the majority,122 requires simply that a detailed statement of environmental impacts, effects, and irretrievable resource commitments, as well as alternatives to the proposed activity, be included in recommendations for “major Federal actions.” 123 And while this “detailed statement” is only “the outward sign that the environmental values and consequences have been considered during the planning stage of agency actions,” 124 the Act does not prescribe exactly how this consideration must be made. Thus, any NEPA-based review consistent with Vermont Yankee II must be limited to a scrutiny of compliance with only the “outward signs” of environmental consideration clearly prescribed by the Act.125

¶583Notwithstanding the Supreme Court’s clear guidelines, however, Judge Bazelon has again strayed beyond judicial province to register his dissatisfaction with the methodology underlying the Table S-3 Rule and to prescribe “procedural” mandates which, however promotive of an ideal that environmental concerns play a vital role in *536government decisionmaking, simply are not among those required by Congress under NEPA.126

¶584The majority’s first novelty is the elevation of “uncertainties” to the level of separate environmental impacts, effects, or costs. Although this is no easy task in logic, since uncertainty is a quality inherent in all impacts as well as benefits, of which there is less than complete certitude, the equation is accomplished semantically with apparent ease. Pointing to “1) uncertainty concerning the integrity of the [projected] permanent repository ... and 2) uncertainty over whether and when such a repository . . . will be developed,”127 he concludes that “these uncertainties reflect two environmental costs of licensing a plant.”128 From that point “costs” are treated as an equivalent to “uncertainties,” and uncertainties thus become costs which must be considered under NEPA.

¶585Judge Bazelon’s prescription does not end there, however. Under his analysis no simple consideration of costs will do: “Although the Commission did consider these uncertainties, it did not do so in a manner that would allow licensing decisions to be affected.”129 The majority’s bottom line is that uncertainties may be fully considered only if openly balanced against benefits, as costs now traditionally are. This, it is maintained, is the type of consideration described in Calvert Cliffs’;130 and thus, we are led to conclude, is the type of consideration required by NEPA in this case. And because the Commission “did not rule that the [uncertainties] were insignificant, [or] rule that they were outweighed by generic benefits that would also be excluded from the licensing boards’ consideration,”131 and because the promulgation of a rule calling for an assumption that post-sealing repository releases would be zero prevented licensing boards from considering uncertainties in their own balancing,132 “the Commission directly contravened NEPA’s requirement that environmental costs be considered ‘at every stage where an overall balancing of environmental and non-environmental factors is appropriate.’ ”133

¶586Thus, in a series of small steps, Judge Bazelon has held that uncertainties in the assumptions underlying the figures in the fuel cycle rule can be considered, consistent with NEPA, only as separate environmental costs, balanced in common EIS practice against benefits. He has severely qualified and limited the Commission’s authority to determine by an otherwise reasonable generic process that certain factors do not merit separate consideration in individual *537licensing proceedings.134 Clearly, the requirements described by Judge Bazelon are not among the procedural requirements “stated in the plain language of [NEPA]; ”135 they are “creature[s] of judicial cloth, not legislative cloth,”136 and are an improper basis for invalidating the Rule. Our critical review of an agency’s action, such as the S-3 Table here under scrutiny, ends with a determination that the decision-makers have satisfied the key “procedural” requirement of considering environmental consequences of and alternatives to the proposed action. Even though NEPA provides that environmental considerations must be made “to the greatest extent possible,” we may not, under the guise of close scrutiny for procedural compliance, dictate to the agencies just how this consideration is best made. As each of the four major Supreme Court NEPA cases137 has shown, judicial review of agency compliance with NEPA is to be tempered by a recognition that full compliance is measured against the agency’s structuring of its own proceedings, in which the agency is to be accorded the greatest deference.

¶5873. “Reasoned Decisionmaking’’

¶588I agree with Judge Bazelon’s statement that “a reviewing court must set aside an agency finding as arbitrary if it determines that the finding is not based upon consideration of relevant factors or if it is based on a clear error of judgment.” I strongly disagree, however, that this rule, properly applied to this case, should yield the result reached by the majority.

¶589Although the fact is not specifically acknowledged, it is obvious from a careful examination of Judge Bazelon’s opinion that the majority’s holding against the Table S-3 Rule is rooted simply in its dissatisfaction with a single conclusion underlying the Rule: that licensing boards effectively may ignore the uncertainties inherent in any projections related to long-term storage of nuclear wastes in favor of the probability-based zero-release figure. Judge Bazelon concedes that “uncertainties can be assessed generically, and that attendant risks can be measured generically,”138 but states categorically that “the Commission cannot find the environmental cost represented by the uncertainties to be zero unless their cost is, in fact, zero.” 139 He has obviously made from the zero-release figure included in the Rule something which it is not — a finding of fact rather than simply a practical estimate for limited purposes. A careful review of the Commission’s contemporaneous explanations convinces me that there is no basis for finding this determination by the NRC to be arbitrary, capricious, or clearly erroneous; nor is it “otherwise not in accordance with law,” as the majority suggests. The majority has simply substituted its “expertise” for that of the Commission.

¶590The relevant question with regard to the zero-release assumption is not whether the zero figure itself is precisely accurate but *538whether the Commission’s decision to adopt it was reasoned. The first step must be to recognize that the figure was never meant to be a “factual finding,” as the majority proposes;140 it is intended only as a generic determination of the appropriate weight to be accorded in licensing proceedings to risks of radioactive emission from long-term waste storage. The Commission did not decide that releases would never occur at the projected federal repository. It only decided, in view of the staff’s assumption that fission-product gases would be released prior to sealing and its finding of extremely low probability of repository failure, that “taking post-sealing releases as zero does not significantly reduce the overall conservatism of the table.” 141

¶591As noted earlier, the majority concedes that “the Commission’s zero-release assumption is probably characterized better as a decisionmaking device, . . . instructing licensing boards to assume that nuclear waste will have no impact on the environment once it is sealed in a repository, [and] allocatpng] to the Commission sole responsibility for considering the risk that long-lived wastes will not be disposed of so successfully.” 142 Yet rather than to afford the Commission any deference in its decision to include the zero figure “device” in the generic rule, Judge Bazelon has cut to the quick of the NRC’s expertise and judgment: “For an agency to go forward in the face of significant uncertainty and issue such a rule indicates either a failure to consider a relevant factor or a clear error in judgment, . . . [and] that is precisely what the Commission did in promulgating the Table S-3 Rule.”143 The record clearly contradicts this conclusion.

¶592There is no question that the Commission considered relevant factors — including the uncertainties with which Judge Bazelon is so concerned — in deciding to promulgate the S-3 Rule. The record is replete with evidence that the Commission took fair account of these uncertainties. Judge Bazelon in fact observes that “[f]rom the time it proposed the original Rule . . . through its promulgation of the final Rule, the Commission became increasingly candid in its acknowledgment of uncertainties underlying permanent waste disposal.”144 We can demand no more, and the majority’s holding that relevant factors were not “properly considered” because the consideration did not take a particular form or yield a usable result145 exceeds the limits of our judicial prerogative in a substantive review of agency decisions under the APA.146

¶593The Commission’s decision not to reflect uncertainties about long-term waste storage directly in the table was simply part of its overall decision to treat an issue generically. That decision was a quintessential policy judgment.147The Commission chose *539to incorporate into the table only those values to which it could reasonably assign a figure. It did not attempt to quantify the uncertainties surrounding the figures themselves because they were inherently unquantifiable.148 It did not require individual licensing boards to weigh repeatedly the effects of uncertainties because it was aware that individual boards were incapable of doing a better job of analysis than the Commission had already done. It did not institute a separate generic proceeding to consider uncertainties because the Commission expected that long-term effects would be more fully analyzed and understood after the concurrent “waste confidence” proceeding had concluded. In view of all of these considerations, I do not believe the Commission abused its discretion by finding “no advantage in having licensing boards repeatedly weigh” for themselves the unquantifiable uncertainties inherent in the rule it adopted — a table whose values mixed both fact and prediction.

¶594Nor did the Commission fail to take a hard look at the whole problem before it. Its avowed objective was to produce a conservative, noncomprehensive table of model fuel cycle impacts; its methodology was directed toward that objective. Its working assumptions were revealed, alternative theories exposed and explained, and its ultimate rationale set forth in a logical and comprehensible manner. The Commission’s decision not to search out and eliminate all uncertainties from its table can hardly be characterized as irrational in view of the limited purpose for which that table was being created.

¶595There was no clear error in the Commission’s conclusion that the use of a zero-release figure, rather than one which reflected a post-sealing release probability which was zero to many decimal places, would have little effect on an individual board’s decision to license any given plant.149 Even after considering the uncertainties involved in its projections of long-term waste storage techniques, the NRC concluded that the probabilities (of which uncertainty is itself an element) still favored the assumptions made and that the presence of uncertainties required no modification of the judgmental zero-release figures. This conclusion did not foreclose further investigation into or consideration of the uncertainties, and it did not preclude the licensing boards from considering uncertainties which were not separately considered in the Commission’s generic determination. It was not a conclusion which was outside the realm of reasonableness. A fortiori, I cannot find the Commission’s decision to adopt the entire table, of which the zero-release figure was but one small part, arbitrary and capricious, given the compensating conservatism of the rest of the table.150

¶596*540Nor can I say, in light of recent precedent, that the NRC has shirked its substantive obligations under NEPA. After Strycker’s Bay Neighborhood Council, our only role “is to insure that the agency has considered environmental consequences.” 151 Here the Commission satisfied its obligation to consider those consequences in two ways: by considering whether the assumption of complete repository integrity (inherent uncertainties and all) would disrupt the overall conservatism of Table S-3 and skew subsequent environmental cost-benefit analyses; and by permitting the significance to the environment of the chosen fuel cycle impact values to be the subject of discussion at individual licensing proceedings.

¶597I cannot avoid contrasting Judge Bazelon’s surprisingly stringent review of the Commission’s conclusions concerning the technological feasibility of the assumptions underlying the values in Table S-3 with his deferential, straightforward, and proper application of the arbitrary and capricious test to the NRC’s conclusions of economic feasibility. He concedes that standards guiding conclusions concerning economic feasibility “may be based on realistic, conservative, and reasoned forecasts,”152 yet the forecasts upon which the Commission based its conclusions of technological feasibility were no less “realistic, conservative, and reasoned.” And he is willing to look to the record as a whole for evidence that the NRC considered factors relevant to dollar cost and that it “reached a conclusion that is within the range of reasonability,” 153 yet is unwilling to afford the same deference to the Commission’s consideration of the uncertainties relevant to its technological predictions.

¶598I am puzzled only by Judge Bazelon’s decision not to apply the standard which tempered his substantive review of the NRC’s economic conclusions to the case as a whole.154 If in the economic arena, then a fortiori in the technological arena, the court must accord to the Commission the deference due in this case.

¶599Based on this review of the authority upon which the NRC acted in this informal rulemaking, the procedures it employed, and the stated rationale for its decision, I believe we have ample ground to affirm.

¶600IV. LIVING WITH UNCERTAINTY

¶601Having expressed my concerns with the particulars of Judge Bazelon’s analysis, I am compelled to respond specifically to the central, and equally harmful implication of the majority’s opinion. Whether his holding is based outwardly on procedural or substantive grounds, the effect of the majority’s analysis is to state that it is error for the Commission to proceed in the face of admitted uncertainties.

¶602In our everyday lives we make countless minor and major decisions, hopefully without stepping beyond the bounds of reason, despite unfathomable uncertainties. We drive our cars without understanding fully the potential risk of injury and death; we eat, drink, and breathe without total certainty that the substances we ingest will not cause long-term disease; we plan for our futures without assurance that that fu*541ture will not be obliterated by unexpected wars, plagues, or natural disasters. Of course we try to evaluate the risks of automobile accident, fatal disease, and possible calamity as well as we can. But when those risks are truly incalculable, and potential outcomes are truly uncertain, we' necessarily face a decision: do we stop until all uncertainties are resolved, or do we proceed cautiously in the face of uncertainty, making tentative assumptions and predictions, and revising and perfecting those predictions as more information becomes available?

¶603In the nuclear power area it is Congress which has made the decision to proceed in the face of uncertainties.155 Congress has charged the NRC not only with authority and discretion to decide how best to proceed, but also with a mandate to predict likely future developments.156 As a reviewing court we are entitled to demand that the Commission’s predictions be based on logic and the best available information; we may further demand that the Commission seek out new information as it becomes available, and that it continually modify its rules to reflect the state of existing knowledge.157 A reviewing court exceeds its authority, however, when by the stringency of its review it effectively forces an agency to employ new procedures or to rewrite its rules until it reaches what the court believes is the best or correct result.158

¶604Judge Bazelon’s opinion today invites this court to exceed the scope of its authority in just this manner. By holding that generic uncertainties must be treated as separate environmental impacts which, unless explicitly factored into a generic rule,159 must be considered anew in each individual proceeding, Judge Bazelon is dictating to the Commission when and where, and under what conditions, it must consider a policy question Congress has empowered it to decide. Yet, after Vermont Yankee II, courts must candidly acknowledge that the choice of when, where, and under what conditions the regulatory agency makes such policy determinations lies within the agency’s discretion, especially when uncertainty is rife and technology is fast-developing.

¶605It is not clear just how the invalidation of the S-3 Rule and the remand ordered in this case will help the NRC to make a better decision than it has already made. Whenever toxic materials are placed in a container, a risk is created that human lives will be endangered. The magnitude of that risk, however, depends on a variety of factors, including the amount and toxicity of the materials being isolated, the duration of their isolation, and the long-term integrity of their container. A comprehensive assessment of the likelihood of injury to human life from waste repository releases would require examination and evaluation of al*542most an infinite and at this time incalculable number of variables.160

¶606Judges Bazelon and Edwards have effectively imposed upon the NRC and its licensing boards an impossible task of predicting this court’s response to their activities. The agency cannot be sure that another aspect of its rule or procedure will not be discredited in a future appeal unless it hunts down every factor it can think of and attempts somehow to qualify and evaluate its uncertainties as “environmental costs,” an equivalence which has not been thought to exist before. It goes without saying that such an •effort would require an enormous commitment of agency time and resources. The only certainty achievable by this process— and it will be achieved — is delay in the development of nuclear power.

¶607More significantly, even if the NRC chose to devote all of its time and staff to studying the risk to human life of long-term waste storage — at best a questionable allocation of agency resources161 — it still could not root out all uncertainties.162 Even if it managed by further research to place boundary values on those uncertainties, and thus succeeded in producing a “risk value,” 163 of some sort, the NRC still would have accomplished only half of its statutory task. At some point the agency would still have to decide whether or not that level of risk and uncertainty was an acceptable one.164

¶608*543There can be no doubt that the decision whether to stop or proceed in face of a certain level of risk and uncertainty is a policy choice clearly within the agency’s discretion. Yet the majority’s opinion today amounts to nothing more clearly than a judicial proclamation that the current level of risk-assumption is unacceptable. As then-Professor (now Judge) Breyer pointed out with respect to Judge Bazelon’s Vermont Yankee I opinion, however, this kind of risk-acceptability determination disguised as “hard look” judicial review “allow[s] courts to play too prominent a role in determining how the United States will produce energy in the future.”165 Were courts to apply Judge Bazelon’s unusually stringent standard of review to other NRC rulemakings, alternative energy sources— whose production is not so carefully regulated and whose long-term environmental effects are even less well-known — will become artificially attractive to the public utilities who must choose the most economical, reliable, and accessible of the available sources of energy generation.166 Furthermore, if judges myopically focus on the risks and uncertainties peculiar to any particular type of energy, they will likely create another, equally real and equally problematic type of uncertainty — namely, uncertainty about regulatory delay which destroys the regulated firms’ incentive to innovate.167

¶609At oral argument in this case, counsel for the petitioners assailed the Commission for failing to reflect in its rule one particular type of risk — the risk of repository leakage resulting from random drilling. According to probabilities, counsel argued, such drilling could cause a repository leak once every 2,500 years — in retroactive perspective, once from now to before the Battle of Marathon. Given that some have projected the expected life of a long-term waste repository as 250,000 years, counsel contended that the Commission had ignored a “substantial risk.”168

¶610*544Lord Rothschild, a former director of the British Advisory Council for Science and Technology, has made a telling point about such “apparently authoritative utterance[s]” about “substantial risks”:

There is no such thing as a risk-free society.... But there is no point in getting into a panic about the risks of life until you have compared the risks which worry you with those that don’t — but perhaps should. Comparisons, far from being odious, are the best antidote to panic.169

¶611Even assuming the worst — that counsel is perfectly correct170 and that a repository failure caused by random drilling would in fact cost thousands and thousands of lives171 — before we decide to panic we should compare the risks described by counsel with some of the risks we normally confront, and accept, in our everyday lives.

¶612In effect, petitioners’ counsel urges us to postpone all nuclear power plant construction because the Commission has adopted a rule which removes from individual licensing proceedings the consideration of a risk substantially less than the risk that he would die on a given day from a volcanic eruption172or from common influenza!173I think it safe to say that such risks have never stopped petitioners’ counsel from making either short-term or long-term plans in his everyday life. Indeed, he would probably deny that he had even failed to “consider” those risks; instead, he would probably assert that he had considered and dismissed them, just as we daily dismiss the countless possible, yet unpredictable, risks and uncertainties which fill *545our daily lives. I find it highly anomalous that counsel so fervently argues that far smaller risks should prove not merely significant, but dispositive, in an area so multifaceted and complex as the NRC’s regulation of the licensing of a light water power reactor.

¶613V. CONCLUSION

¶614A close examination of the majority’s opinion today reveals that it has taken no more than a giant step sideways from an analysis rejected unanimously by the Supreme Court in Vermont Yankee II. It matters little that Judge Bazelon’s latest approach has taken on a slightly different form or is presented under a different banner than his analysis in Vermont Yankee I. Its focus and effect are unchanged. Vermont Yankee III does not cure the first-round defects of Vermont Yankee I; it compounds them.

¶615Simply put, the majority has created a new standard by which to gauge agency rulemaking against NEPA. It announces that uncertainties, even though inherent in the projections underlying environmental risk identification itself, must be considered as a separate category of environmental cost. It holds further that consideration of these uncertainties, however otherwise obvious and clearly disclosed in the rulemaking record, is insufficient if not made in a particular form or yielding a “usable” result — which in the last analysis is simply a result satisfactory to this court. Such a standard is clearly not mandated by NEPA and cannot be judicially foisted upon the Commission, however noble Judge Bazelon’s intentions.

¶616In view of the limited purposes of the fuel cycle rule, the other proceedings concurrently being conducted by the NRC, the overall conservatism of Table S-3, the massive record before us, and the rationale clearly stated in the Commission’s statement of basis and purpose, I cannot say that the Commission acted arbitrarily and capriciously in promulgating its final rule. The Commission acted well within the scope of its authority throughout the S-3 proceeding; it faithfully observed all statutorily required procedures; and it acted reasonably both in adopting the assumption of complete repository integrity and in generically considering the uncertainties surrounding long-term fuel cycle impacts.

¶617This is a rare case indeed. The Supreme Court has already unanimously mandated both the standard and the intensity by which we should scrutinize the very agency action being challenged. Faithful observance of that mandate demands that we now find that the agency’s rule was reasonable. The majority has not done so. The decision and the stated rationale on which it is based, taken in conjunction with the recent action of this court in halting all operation at undamaged Three Mile Island Unit 1 on the basis of another completely novel theory, signal that this court has effectively taken over control of the nuclear industry. This is not the way I read either the substantive law or a judicial commission.

¶836On Petition for Rehearing

¶837Before BAZELON, Senior Circuit Judge, GEORGE C. EDWARDS, Jr.*, Chief Judge, United States Court of Appeals for the Sixth Circuit, and Wilkey, Circuit Judge.

¶838ORDER

¶839PER CURIAM.

¶840Upon consideration of the petitions for rehearing filed by respondents and by intervenors Commonwealth Edison Company, et al., and Pacific Legal Foundation, it is

¶841ORDERED, by the Court, that the aforesaid petitions are denied.

¶842Statement of Senior Circuit Judge Bazelon as to why he voted to deny rehearing, attached.

¶843Circuit Judge Wilkey’s position is set forth in his statement attached to the en banc order entered this date.

¶844*546Statement of Senior Circuit Judge BAZELON as to why he voted to deny rehearing.

¶845In voting to deny these petitions for rehearing, I have carefully considered the parties’ arguments and have concluded that no issue has been raised that has not been addressed in our opinion. I think it worthwhile, however, to respond briefly to the salient points of the petitions.

¶846The petitioners assert, first, that we have prescribed procedures by which the NRC must consider the environmental impact of fuel-cycle activities, and second, that we have substituted our judgment for that of the NRC. In fact, we did neither. We held only that the NRC’s environmental consideration must conform with the mandate of NEPA, as interpreted in Calvert Cliffs’ Coordinating Committee, Inc. v. AEC, 449 F.2d 1109 (D.C.Cir.1971).

¶847In addition, the NRC states that “[t]he panel envisaged a procedure in which waste disposal uncertainties would be quantified as costs.... ” NRC Petition at 10 (emphasis added). We said nothing about quantification; we said only that uncertain environmental costs must be considered in such a manner that they can potentially affect the ultimate decision to take an action. The Commission further' argues that, under NEPA, an agency should be able to assess environmental costs in the abstract and subsequently exclude them entirely from consideration when the decision is being made whether to go forward with a project. Id. at 11. We held, and I strongly believe, that this type of consideration violates NEPA, and if permitted, would eviscerate the procedural regimen that NEPA established. As this court stated in Calvert Cliffs’, NEPA requires that “environmental issues be considered at every important stage in the decisionmaking process concerning a particular action — at every stage where an overall balancing of environmental and nonenvironmental factors is appropriate and where alterations might be made in the proposed action to minimize environmental costs.” 449 F.2d at 1118.

¶849On Suggestion for Rehearing En Banc

¶850Before ROBINSON, Chief Judge, BAZELON, Senior Circuit Judge, WRIGHT,* Circuit Judge, GEORGE C. EDWARDS, Jr.,… Chief Judge, United States Court of Appeals for the Sixth Circuit, and WILKEY, WALD, MIKVA and GINSBURG, Circuit Judges.

¶851ORDER

¶852PER CURIAM.

¶853The suggestions for rehearing en banc filed by respondents and by intervenors Commonwealth Edison Company, et al., Pacific Legal Foundation, and Baltimore Gas & Electric Company, et ah, have been circulated to the full Court and no member of the Court has requested the taking of a vote thereon. On consideration of the foregoing, it is

¶854ORDERED, by the Court, en banc, that the aforesaid suggestions are denied.

¶855Circuit Judge Wilkey does not ask for en banc consideration because he believes nothing should delay consideration of this case by the Supreme Court. Circuit Judges Tamm, MacKinnon, Harry T. Edwards and Bork are recused.