Sa PACK, b Draft #2 7m 12/3/79 Mrs. Ruth-G. Van Cleve, Director Office of Territorial Affairs U. S. Department of the Interior Office of the Secretary Washington, D.C. 20240 Dear Mrs. Van Cleve: Reference is made to your letter of October 22, 1979, in which you state that the Department of the Interior is considering the agricultural redevelopment of Enjebi Island and the reestablishment of a community on that island for the Enjebi people. As part of this consideration you requested estimates of the time which must elapse before exposure levels on Enjebi Island would meet exposure limits. Current estimates of the number of years which must pass if exposure limits are to be adhered to are based upon the potential dose estimates provided in the Preliminary Dose Assessment Report prepared by the ~ . . : = staff of the Lawrence Livermore Laboratory (LLL). fhese dose estimates a have been compared to the exposure guidance 5 rand, based spon known « radioactive decay rates ofthe radionuclides involved, time intervals have been calculated. U. S$. Federal Radiation Council recommended exposure levels (adopted also Pyee .Envirogmental Protection Agency) didual ‘in any, one. year (and ¢ are 500 vem tothe,maximum exposed.invi assumesthat thesaximun exposed individual does not vary from the average popylation exposure by. more than a factor of 3, resulting ina recommended average population exposure level of170 mrem per year) | and 500mrem over a 30 year period. Atomic Energy Commission | recommendations, recognizing the uncertainties inherent in such guidance for the maximum dose estimates, were one-half of the FRC Sm ee ep ve . ep . _~¥E cane. tows vetpee een mee wre ot eee he “, c: ekg +:Los rier? het. ea teh Z, : ’ ree sae eT : . D4 YY. a JS Pe