separate statement concurring in result:
Licensing a nuclear reactor unquestionably constitutes a “major Federal actionQ significantly affecting the quality of the human environment” requiring a “detailed” environmental impact statement under section 102(2)(C) of NEPA, 42 U.S.C. § 4332(2)(C) (1970). Approval of such a facility, which inevitably will produce high level radioactive wastes, some of which must be isolated from the “biosphere” for a quarter of a million years, undeniably necessitates an “irreversible and irretrievable commitmentO of resources” within the meaning of the Act. 42 . U.S.C. § 4332(2)(C)(v). A panel of this court has previously indicated that NEPA requires potential environmental problems of this magnitude to be dealt with in advance of such a substantial commitment, not ignored until new commitments inevitably follow from the old. See, e.g., Calvert Cliffs’ Coordinating Comm. v. AEC, 146 U.S.App.D.C. 33, 449 F.2d 1109, 1128 (1971).1 I agree with the majority that NEPA requires the Commission fully to assure itself that safe and adequate storage methods are technologically and economically feasible. It forbids reckless decisions to mortgage the future for the present, glibly assuring critics that technological advancement can be counted upon to save us from the consequences of our decisions. I further agree with the conclusion of the majority that it is impossible to determine from the record before us whether the Commission has fulfilled its statutory obligation under NEPA in adopting the S-3 table, in effect deciding that the incremental environmental effect of storing the waste of an additional nuclear reactor is negligible, or whether it has uncritically adopted as its own the undocumented conclusions of a single witness that the waste storage issue is a “non-problem” with which the Commission need hardly concern itself at this time. Accordingly, 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. I cannot, however, without qualification, endorse the approach the majority has taken to reach this result or its suggested disposition on remand.
The majority appears to require the Commission to institute further procedures of a more adversarial nature than those customarily required for informal rulemaking by the Administrative Procedure Act, 5 U.S.C. § 553 (1970).2 The Commission chose to proceed by “hybrid” rulemaking below, allowing petitioners to present oral arguments before the Commission and subjecting participants to questions, but not permitting participants to cross-examine. Majority, supra note 59. By so proceeding the Commission exceeded the minimum procedural requirements of section 553.3 In my *362view, the deficiency is not with the type of proceeding below, but with the completeness of the record generated.4 More procedure will not, in this case, guarantee a better record, and a better record can be generated without reopening the oral proceeding at this time. We cannot conclude confidently from this record whether the Commission’s staff considered all relevant factors, including the facts petitioners call to our attention, in reaching the figures embodied in Table S-3; nor can we conclude from Dr. Pittman’s oral statements, substantially devoid of documentation, whether these figures represented conclusions drawn from more exhaustive research into the waste storage problem conducted by the head of the Commission division charged with this task. If Dr. Pittman’s conclusions were so based, I believe the Commission is entitled to accept them, provided, of course, it is assured that they are reasonably objective.5
I am also troubled by two other aspects of the majority opinion. First, I am distressed because I believe the majority opinion fails to inform the Commission in precise terms what is must do in order to comply with the court’s ad hoc standard of review.6 The majority sends the waste storage issue back to the Commission for a “thorough ventilation.” This language, of course, means very little in procedural terms. In order to aid the Commission in filling in the gaps in the record, the majority enumerates a number of procedural alternatives in varying degrees of formality, some less intrusive into agency prerogatives than others. Majority, supra at 178 U.S.App.D.C. 361, 547 F.2d 658. Then, heeding the Supreme Court’s admonition in FPC v. Transcontinental Gas Pipe Line Corp., 423 U.S. 326, 96 S.Ct. 579, 46 L.Ed.2d 533 (1976) (per curiam), that we may not, except in extraordinary circumstances, specify agency procedures on remand, the majority declines to give the Commission any direction as to which procedure or combination of them, will suffice. The Commission is thus left to decide which to adopt, further confused by the majority’s statement that, “It may be that no combination of the procedures mentioned above will prove adequate, and the agency will be required to develop new procedures to accomplish the innovative task of implementing NEPA through rulemaking.” Majority, supra at 178 U.S.App.D.C. 356, 547 F.2d 653. Such specificity resembles a standardized test in which there are numerous possible answers, including “all of the above,” “none of the above,” or “various combinations of the above.” The result, I believe, is entirely predictable: the Com*363mission may or may not adopt one of the majority’s suggestions, but will in any case seek to comply by mechanically generating more “negative” information respecting current problems with disposal of high level radioactive wastes and then will “overcome” this information with citations to favorable studies and articles. Ultimately, of course, the Commission must decide which information to accept and which to reject, regardless of the type of procedure used. The majority opinion appears to recognize as much when it volunteers that, “On the other hand, the procedures the agency adopted in this case, if administered in- a more sensitive, deliberate manner, might suffice.” Majority, supra at 178 U.S.App.D.C. 356-357, 547 F.2d 653-654 (citation omitted). This time, however, the decision whether licensing an additional reactor is worth the additional environmental risk would be one of policy or risk assessment and, consequently, would be reviewable only according to the customary “arbitrary, capricious” standard. Amoco Oil Co. v. E. P. A., 163 U.S.App.D.C. 162, 501 F.2d 722, 741 (1974). I believe it almost inevitable that, after fully considering the problems and alternative methods of waste disposal and storage, the Commission will reach the same conclusion and therefore see little to be gained other than delay from imposing increased adversarial procedures in excess of those customarily required.7
This brings me to my second, related concern with the majority’s approach. I believe the majority’s insistence upon increased adversariness and procedural rigidity, uneasily combined with its non-direction toward any specific procedures, continues a distressing trend toward over-formalization of the administrative decisionmaking process which ultimately will impair its utility. As Judge Wright has recently noted, the administrative response to overuse of judicial imposition of such ad hoc procedural refinements is easily foreseeable. Fearing reversal, administrators will tend to over-formalize, clothing their actions “in the full wardrobe of adjudicatory procedures,” until the advantages of informal rulemaking as an administrative tool are lost in a heap of judicially imposed procedure. Wright, The Courts and the Rulemaking Process: The Limits of Judicial Review, 59 Cornell L.Rev. 375, 387-88 (1974).8 The majority’s reliance upon the so-called “hybrid rulemaking” cases9 for its conclusion that the procedures prescribed by section 553 are inadequate for resolution of the complex issues involved in this case and its insistence that the Commission adopt more formal adversary procedures are, I believe, misplaced. Admittedly, there are rare cases in which “basic *364considerations of fairness” require procedures more adversarial than those prescribed by section 553. See Majority, supra at 178 U.S.App.D.C. 344-346, 547 F.2d 641-643, quoting from Respondent’s Brief at 13-14. I cannot agree, however, that this case requires us to reach this issue. Remanding an agency decision with instructions to initiate such procedures is an extraordinary judicial remedy which, I believe, should be reserved for extraordinary cases.
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 section 553, but to remand for an explanation of the basis of Dr. Pittman’s statements and of the staff’s numerical conclusions,10 i. e. for the documentation which the majority finds so conspicuously lacking.11 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 Dr. Pittman concluded that the waste storage problem is already technologically and economically soluable. If .it cannot, then 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.
. A major purpose of NEPA was to avoid the limiting effect of incremental decisionmaking by confronting environmental problems before foreclosing alternative methods of dealing with them. See S.Rep.No.296, 91st Cong., 1st Sess. 5 (1969), quoted in Majority, supra at 178 U.S.App.D.C. -, 547 F.2d 639. To this end, NEPA requires a thorough cost-benefit study in each case before undertaking major federal action affecting the quality of the human environment. Calvert Cliffs’ Coordinating Comm. v. AEC, supra at 1128.
. The standard of review under section 553 has been the subject of considerably discussion in recent years, especially within this judicial circuit. See, e. g., the cases and articles cited in Majority, supra note 23.
. Section 553 imposes only three obligations on the rulemaker. First the rulemaker must give adequate and effective notice of “either the terms or substance of the proposed rule or a description of the subjects and issues involved.” Secondly, he must “give interested persons an opportunity to participate . through submission of written data, views, or arguments with or without opportunity for oral presentation.” Finally, the rulemaker must “incorporate in the rules adopted a concise and *362general statement of their basis and purpose.” 5 U.S.C. § 553 (1970). See generally Verkuil, Judicial Review of Informal Rulemaking, 60 Va.L.Rev. 185 (1974).
The “concise and general statement” required by section 553 must be sufficiently complete and detailed to enable the court to accomplish its reviewing function, assuring itself that the agency has engaged in reasoned decision-making, has given serious thought to alternative rulings, and has provided reasoned explanations for controversial normative and empirical determinations. In short, “the reviewing court must satisfy itself that the requisite dialogue occurred and that it was not a sham.” Wright, The Courts and the Rulemaking Process: The Limits of Judicial Review, 59 Cornell L.Rev. 375, 381 (1974).
.The majority also recognizes that the procedures utilized by the Commission might suffice “if administered in a more sensitive, deliberate manner.” Majority, supra at 178 U.S.App.D.C. 356, 547 F.2d 653.
. See Environmental Defense Fund, Inc. v. Corps of Engineers, 470 F.2d 289 (8th Cir.), cert. denied, 412 U.S. 931, 93 S.Ct. 2749, 37 L.Ed.2d 160 (1972), in which the Eighth Circuit Court of Appeals held that, although NEPA requires agencies to evaluate objectively their projects, it does not require agency officials to be subjectively impartial. In other words, NEPA assumes as inevitable an institutional bias within an agency . . and erects the procedural requirements of § 102 to insure that there is no way the decision-maker can fail to note the facts and understand the various arguments advanced by the plaintiffs if he carefully reviews the entire environmental impact statement.
Id. at 295 (quotation marks and citation omitted).
. Judicial imposition of procedural requirements on an ad hoc basis is criticized in Wright, supra.
. It has been argued that those cases in which we have granted a limited right of cross-examination on remand have afforded little relief other than delay and a tool with which to bargain for substantive concessions. Williams, "Hybrid Rulemaking” Under the Administrative Procedure Act: A Legal and Empirical Analysis, 42 U.Chi.L.Rev. 401, 436-48. It would seem, therefore, that the right of cross-examination at a rulemaking proceeding frequently is better to have and be denied than to utilize.
. A further problem with over-reliance on the hybrid rulemaking approach has its roots in the hostility of some judges to all forms of substantive review of agency decisions. The line between substantive and procedural review is, of course, a hazy one. The same judges who most vehemently protest against judicial intrusions into the substance of administrative action, especially in highly technical areas, may not hesitate to require relatively more procedure of an agency when they dislike its substantive result. There is, I believe, a danger that judges will feel less restrained in requiring agencies to adopt procedures in excess of those required by the APA when review is couched in procedural, rather than substantive, terms. The preoccupation of the majority opinion in this case with the half-life of the plutonium atom and the myriad of geological and other technical difficulties one faces in attempting to safely store a highly toxic substance for a quarter of a million years demonstrates that judges cannot avoid the task of immersing themselves in difficult and often technical matters in order to evaluate administrative action and assure themselves that the agency has in fact dealt with all major issues. Because the relative environmental importance of the waste disposal issue before us is the subject of some controversy, arguments about whether our focus here is “procedural” or “substantive” may be more semantic than determinative.
.See the cases cited at note 23 of the majority opinion.
. As the majority states, due process considerations probably mandate that petitioners be allowed to comment upon any additional information assembled by the Commission. Neither the Constitution nor the Administrative Procedure Act, however, directs the Commission to allow additional oral presentation, cross-examination, or any other procedures in addition to those required by section 553.
. The extent of the required statement of basis may vary, of course, according to the precise demands and issues of each particular case, but, “[a]t a minimum, the statement should refer to relevant submissions by interested parties and should rebut or accept these submissions in an orderly fashion.” Wright, supra at 381. This court has also distinguished between factual determinations and policy choices more peculiarly within the expertise of the 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. Amoco Oil Co. v. Environmental Protection Agency, 501 F.2d 722, 163 U.S.App.D.C. 162 (1974). 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.
Id. at 741.
Often, of course, an agency ruling will encompass both factual determinations and policy choices. This is such a case. For example, the decision to treat the waste storage issue through generic rulemaking because it is common to all licensing decisions is clearly a policy determination within the agency’s special expertise which we should review only for clear abuse of discretion. See NLRB v. Bell Aerospace Co., 416 U.S. 267, 94 S.Ct. 1757, 40 L.Ed.2d 134 (1974). The decision to license a particular reactor is also a policy or “assessment of risks” decision within the agency’s discretion, provided it has adequately considered all underlying factual issues, including the waste storage issue, and has determined to its own satisfaction that safe methods of production and waste storage are already technologically and economically feasible. Finally, once so assured, the decision to postpone until later the question as to which of several feasible methods should be utilized is also, I believe, a policy, or risk assessment, decision.
This case, however, involves related factual determinations for which we must find support in the statement of basis required by section 553. Of particular relevance here is Table S-3, which reduces the environmental effect of licensing an additional reactor to certain numerical values and, in effect, concludes that it is negligible. The claimed bases for the judgments expressed in numerical terms in Table S-3 are the data assembled by the staff in the draft Environmental Survey, adopted without substantial modification as Table S-3 and thus embodied in the final rule. As the majority indicates, neither the Survey itself, the back-up documentation to which it refers, nor the oral and written testimony offered at the hearing adequately supports these factual conclusions with respect to the waste disposal issue. Majority, supra at 178 U.S.App.D.C. 348-349, 547 F.2d 645-646. the detailed explanation which characterizes other portions of the Environmental Survey is notably absent from this portion.