The transport of 129I and 137Cs from European reprocessing plants through the Kara Sea

A simple method is described for estimating radionuclide tracer transit times for Norwegian Coastal Current water to arbitrary locations in the Arctic Ocean. The primary source of the radionuclides (137Cs and 129I) is Atlantic-origin water contaminated by inputs from the 1986 Chernobyl accident, atmospheric weapons tests and the Sellafield (UK) and La Hague (France) reprocessing plants. The 129I and 137Cs input functions for Atlantic water entering the Arctic Ocean have been estimated from reconstructed (proxy), radionuclide release records for Sellafield and La Hague and transfer factors referenced to a location of 60 deg N in the Norwegian Coastal Current. A mixing/advection model formulated to estimate transit times to sampling locations in the Arctic Ocean is illustrated using 137Cs and 129I tracer data from the Kara Sea. Tracer data from 1993 are consistent with previous estimates of transit times of 1-3 y for transport from the Norwegian Coastal Current to the Kara Sea. (author)