Comparison of methods for the determination of retention factors of radionuclides in mineral soils

The migration behaviour of radioactive Ce, Cs, I and Sr in fluviatile and aeolian sands is being examined in laboratory tests. These tests attempt to simulate as far as possible the natural conditions in the field; they are performed as batch and as column experiments. The determination of distribution coefficients (Ksub(d)) by batch experiments is done in two ways: (1) with mixing in rotation machinery; (2) with a continuous recirculation set-up. The results of both types of experimental procedures agree completely within error limits. From measured Ksub(d) values the retardation factors Rsub(D) were calculated. Parallel to these methods of Ksub(d) determination, tracer tests were carried out in column experiments; from these experiments Rsub(D) values were obtained directly. The results of batch tests and column experiments agree satisfactorily for 134Cs+, sup(131/125)I- and 85Sr2+. (author)