T.M. Beasley, Environmental Measurements Laboratory, NY NY

D. Elmore, Purdue University

P.W. Kubik, P. Sharma, University of Rochester

Ground Water 30 (1992) 548

Determinations of 36Cl (T1/2 = 301,000 a) in waters on and near the U.S. Department of Energy's Savannah River Site (SRS) in South Carolina reveal that nuclear fuel reprocessing activities there have released measurable amounts of this radionuclide to the environment. The natural atmospheric flux of 36Cl at the latitude of SRS is 20-25 atoms m^-2 sec^-1. Atmospheric releases of 36CI from SRS, within the site boundaries, have increased this flux by a factor of at least 10 to 20. Approximately 3 X 10^9 Becquerels (Bq) [84 millicuries (mCi)] of site-derived 36Cl have been deposited within 200 km of the plant boundaries. By comparison, fallout of 36C1 from nuclear weapons testing in the 1950s deposited twice this amount of activity in the same area. Surface-water 36Cl concentrations in on-site streams represent about 0.01 percent of the Environmental Protection Agency (EPA) drinking-water standard and therefore pose no health concern. At SRS and similar facilities, this additional source of 36Cl should prove useful for validating ground-water and atmospheric transport models.