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OCR for page 187
APPENDIX F THE COMMITTEE CHAIR'S PERSPECTIVE ON APPENDIX E ROBERT W. FRI In Appendixes C and D, we have presented alternative approaches that EPA might wish to consider in selecting an exposure scenario to be user} in calculating compliance with the standards. As noted in Chapter 3 of the report, these approaches differ chiefly in the assumptions ant! calculational methods used in estimating the exposure of future persons who might be near the repository site. However, there is little scientific basis for predicting events far into the future, such as where people will live, and so developing an exposure scenario for testing repository compliance with the standards is inherently a policy choice. Throughout our report, we have avoided making recommendations that involve policy choices on the grounds that there is by definition a limited scientific basis for selecting one policy alternative over another. We have instead tried to use available technical information and judgment to suggest a starting point for the rulemaking process that will lead to a policy decision. As noted in Chapter 3, a majority of the committee considers the approach of Appendix C to be more clearly consistent with the technical criteria that clefine the critical group in the exposure scenario, and therefore believes that EPA shouicl propose an approach along the lines of Appenclix C. The committee recognizes, however, that other approaches might meet these criteria. I believe that, in his personal statement, Dr. Pigford has become an advocate for a particular choice. He clearly prefers the approach of Appendix D and presents arguments both for his position and against the alternative. He is of course entitled to make this argument. It is important, however, to understand that the argument being presented is fundamentally a policy argument rather than a scientific one. Nevertheless, the issue raised here is an important one. Dr. Pigford advocates an assumption that results, in his words, in calculating " .the extreme of the actual closes in the entire population". In contrast, . 187

OCR for page 187
188 YUCCA MOUN7CAINSTANDARDS Chapter 2 of the report adopts the basic principle of the International Commission for Radiological Protection that the standard should avoid ". . tan extreme case defined by unreasonable assumptions regarding factors affecting dose and risk". Although Appendix D ant! Dr. Pigford postulate a subsistence-farmer scenario based on cautious, but reasonable, assumptions (as described in Chapter 2), some members of the committee believe that the approach Equivocated by Dr. Pigford could become just such an extreme case. Determining when the assumptions in an exposure scenario pass from cautious to extreme is thus a crucial issue in the rulemak~ng process. As such, it requires the fieriest ant] most open public discussion.