EN@rosut — L
Draft #2
12/3/79
Mrs. Ruth G. Van Cleve, Director
Offiee 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). These dose estimates
have been compared to the exposure guidance, and, based upon known
radioactive decay rates of the radionuclides involved, time intervals
have been calculated.
U. S. Federal Radiation Council recommended
exposure levels (adopted also by the Environmental Protection Agency)
are 500 mrem to the maximum exposed invididual in any one year (and
assumes that the maximum exposed individual does not vary from the
average population exposure by more than a factor of 3, resulting in a
recommended average population exposure level of 170 mrem per year)
and 5000 mrem over a 30 year period.
Atomic Energy Commission
recommendations, recognizing the uncertainties inherent in such
nce for the maximum
dose estimates, were one-half of the FRC guida