Management of Commercially Generated Radioactive Waste - U.S. ...

Response
53
RADIOLOGICAL ISSUES
EPA contends that the quotation from NCRP in the final paragraph on draft p. E.1
reflects a bias, in that quotations more favorable to the linear nonthreshold approach to
risk estimation could and should have been included. The NCRP quotation was, indeed, chosen
because it represented the negative point of view, and it was the purpose of this particular
paragraph to reflect that point of view. Most of the rest of the appendix consists of a
positive application of the linear nonthreshold approach, with extensive documentation. It
seemed only proper that the limitations of the approach be also cited.
Draft p. E.3
Issue
In the discussion of BEIR risk estimates, emphasis is put properly on the range of
uncertainty. However, mention is made of the BEIR Committee report that (Reference 1, draft
Appendix E), "With this limitation in mind, the Commi.ttee considers the most likely value
to be approximately 3,000 to 4,000 cancer deaths (or a 1% increase in the spontaneous rate)"
(emphasis added). (113-EPA)
Response
EPA contends that, in the first full paragraph on draft p. E.3, reference should be
made to the fact that the BEIR Committee, while acknowledging uncertainties, did state a
"most likely value" of approximately 3000 to 4000 cancer deaths." The BEIR committee did
not define what they meant by a "most likely value". For the proper appreciation of these
risk factors, the unavoidable uncertainties should be stressed, not a false sense of
certainty.
Draft p. E.3
Issue
The paragraph considered only EPA's Uranium Fuel Cycle documents and states that the
risk estimates there continue to be used by EPA. In reality EPA risk estimates have con-
tinued to change as new data becomes available. In addition to papers published by staff
(e.g., Ellet, Nelson, and Mills, "Allowed Health Risk for Plutonium and Americium Standards
as Compared with Standards for Penetrating Radiation," pp. 587-601 in Transuranium Nuclides
in the Environment, IAEA, Vienna, 1976), various EPA reports (e.g., A Computer Code for
Cohort Analysis of Increased Risks of Death, EPA 520/4-78-012, 1978, or Proposed Guidance
on Dose Limits for Persons Exposed to Transuranium Elements in the General Environment,
EPA 520/4-77-016, etc.) show updated risk estimates and how they were derived. (113-EPA)