PREDICTION CAPACITY OF A SEQUENTIAL EXTRACTION SCHEME

The predictions of a sequential extraction scheme with respect to the mobility of some radionuclides (Sr-85, Cs-134 and Ag-110m) in two Mediterranean sandy and sandy-loam soils, are compared to short-term soil-to-plant transfer factors and soil migration. Total soil-to-plant transfer is higher in sandy soil than in sandy-loam soil. as expected and predicted by the scheme. The relative transfer to plants of Cs-134 and Sr-85 follows the scheme predictions about exchangeable radionuclide fraction, radiosilver being less mobile than expected. Migration in soil of radiocesium and radiostrontium is also higher in sandy soil, especially for the latter radionuclide, the relative behavior of these two radionuclides being nearer to the bioavailable radionuclide fraction defined by the scheme. However, the scheme fails in predicting radiosilver migration, which is lower than deduced by the scheme.