Sr-90 and Cs-137 exchange distribution coefficient in soil-water systems

Two methods are proposed for estimating the exchange distribution coefficie nt of Cs-137 and Sr-90 in natural soil-water systems: effective selectivity and selective sorption of Cs-137. Particles for classifying soild and depo sits as a function of the effective selectivity coefficient are proposed. U sing the first method, the Sr-90 distribution coefficient can be estimated if the sorption properties of the medium are known to within 50%; for Cs-13 7, the distribution coefficient can be estimated only in order of magnitude . The uncertainty in the prediction of the Cs-137 distribution can be decre ased by determining the characteristics of the selective sorption of Cs-137 : the capacity of selective sorption centers and/or the radiocesium interce ption potential. 3 tables, 8 references.