ARTIFICIAL RADIONUCLIDES IN THE SURFACE SEDIMENTS OF THE IRISH SEA, 1968-1988

The sediments of the Irish Sea are uniquely labelled with a variety of radionuclides released over several decades by the British Nuclear Fu els reprocessing plant at Sellafield, Cumbria. Both the temporal and s patial variations of many of these radionuclides in the surface sedime nts of the Irish Sea have been determined from a large number of sampl es collected over the period 1968-1988. The radionuclides considered i n this study are Cs-137, Cs-134, Pu-239,Pu-240, Pu-238, Am-241, Ce-144 , Ru-106, Zr-95 + Nb-95 and to a lesser extent Cm-243,Cm-244, Co-60, S b-125, Eu-154 and Eu-155. The distributions of these radionuclides in the surface sediments of the Irish Sea are described and the implicati ons for our understanding of the system discussed.