_ ICLELUPIEK 4oisil April 28, 1978 TO: Hal Hollister Director, Division of gberationa] and Environmental] Weep rement of Energy Washington, D.C. FROM: SP #,; L, SY Tat Baifelfe Pacific Northwes’ Liuecstenc: Battelle Boulevard 4 20545 Richland, Washing: 3 52332 Telephone (5093 W. J. Bair Telex 32-6345 Manager, Environment, Health, and Safety Research Program Battelle, Pacific Northwest Laboratories Richland, WA 99352 The Enewetak Advisory Group met on April 26 and 27, 1978 in Denver, Colorado. Present were: W. L. Templeton, C. W. Francis, B. W. Wacnholz, J. Healy, R. 0. Gilbert, R. C. Thompson, R. 0. McClellan, and W. J. Bair. The purpose of the meeting was to consider the following questions: 1. Is it possible to develop dose-related cleanup guidance that would assure that doses to future residents of Enewetak Atoll would not significantly exceed proposed EPA guidelines for transuranics? 2. What advice can be given to the Defense Nuclear Agency on May 3, 1978 to facilitate planning for cleanup of transuranics on Enewetak? 3. What additional information can be obtained that could improve the confidence 4. Can plowing be used as an effective cleanup measure for transuranics in soils? of the dose estimates and cleanup criteria for transuranics? The Advisory Group reviewed information and data provided by DOE-Division of Occupational and Environmental Safety, Lawrence Livermore Laboratory, DOE-Nevada Operations Office, and Defense Nuclear Agency and offers the following response to the above questions. (This pertains only to transuranic elements and does not consider radiation doses from other radionuclides which, the Advisory Group understands, will delay the resettlement of some of the islands for many years.) 1. The Enewetak Advisory Group does not find it possible to develop reasonable Cleanup guidance that would assure that radiation doses from transuranics to future residents would not significantly exceed proposed EPA guidelines. Obviously, the more stringent the cleanup criteria, the greater the degree of assurance; but uncertainties inherent in our present understanding of the problem preclude absolute assurance. One cannot predict'with certainty the contamination levels that will exist in the islands after cleanup--this must be determined at a future time. One cannot predict the lifestyle and dietary habits of every individual who returns to the islands. Perhaps most important, many of the factors that are involved in movement of transuranics in the environment and the deposition and retention of transuranics in human beings are not well established. a ‘ j