Geochemical fractionation of plutonium in anoxic Irish Sea sediments using an optimised sequential extraction protocol.

An optimised five-step sequential extraction protocol, incorporating the use of sodium citrate to inhibit resorption, has been used to assess the solid partition of plutonium under anoxic conditions in intertidal sediments from the Ravenglass Estuary in the north-eastern Irish Sea. The data reveal that the plutonium is predominantly bound to geochemical phases targeted by the acido-soluble and the exchangeable extractants, indicating that a significant proportion of the plutonium in these and similar sediments is associated with relatively mobile geochemical phases. The results are consistent with the relatively high level of plutonium remobilisation now known to be taking place throughout the north-eastern Irish Sea.