The Influence of Mixing Timescales and Re-dissolution Processes on the Distribution of Radionuclides In Northesast Irish Sea Sediments

摘要

The sediments of the northeast Irish Sea contain substantial inventories of contaminant radionuclides as a consequence of past discharges of low-level liquid radioactive waste from the Sellafield nuclear fuel reprocessing plant. Previous work has indicated that onshore transport of this contaminated Sediment is the dominant mechanism of supply of Sellafield waste radionucli- Des to surrounding intertidal and floodplain areas, but an inherent, and Previously unsubtantiated assumption in this work was that past discharges From Sellafield are effectively homogenised in the surface offshore sediment, With respect to ~238Pu/~239, 240Pu and ~241 Am/~239,240 Pu activity ratios, as the result Of mixing on a time scale of a few years.