Sampling and measurement of transuranic elements in interstitial waters of sediments

The construction and installation of porous cup soil solution samplers and their operation in a saltmarsh is described. Levels of transuranic contamination in the saltmarsh sediments are relatively high (up to 930 kBq m−2 for 241Am and 500 kBq m−2 for 239,240Pu), but levels in the interstitial, or sediment-pore, waters are low, generally in the range 1 to 50 mBqL−1. Both 241Am/239,240Pu ratios and concentrations of dissolved transuranic elements are affected by the degree of inundation of the sampling site. These parameters also vary over time in an apparently unpredictable manner. The Kd values (solid/solution distribution coefficients) for Pu and Am are comparable with those measured by other workers at this site.