Evidence for the remobilisation of transuranic elements in the terrestrial environment.

摘要: The transuranium elements, Np, Pu and Am discharged from the BNFL fuel reprocessing plant at Sellafield have accumulated in local environment. processes responsible for their dispersal rely both on physical transportation chemical reactivity. transuranics a complex chemistry, with multiple oxidation states strongly polarising character. In environment, particle active III/IV more mobile VNI state groups are important govern geochemical behaviour subsequent dispersal. Studies of transuranics, particularly Pu, Irish Sea, shown that majority radionuclides liquid effluent Sellafield, quickly becomes associated marine sediments. Their distribution environment is then governed primarily by movement particulate material some sites it has been suggested sediment profiles preserve historical record discharges plant. tidally inundated soils, radionuclide levels greatly enhanced. These soils water-logged long periods year, anoxic accretion rate very low. soil suggests simple sedimentary accumulation mechanism cannot provide an adequate explanation observed. From preliminary studies pore water composition detailed analysis variation isotopic ratios cores, apparent small but significant component inventory mobile. addition, clear mechanisms this mobility allows differentiation between nuclides.