Abstract
Of the radionuclides entering the Esk Estuary from the Sellafield [England, UK] effluent discharges into the Irish Sea, the behavior in the dissolved phase of 106Ru, 134Cs and 137Cs was conservative while that of 238Pu and 239,240Pu was nonconservative. The latter led to the enrichment of Pu in low salinity waters, probably by transfer from the particulate phase. This had repercussions on the distribution of Pu activity in the estuary, and also on the long-term fate of sediment stored Pu.