Abstract: | It was found that the distribution of certain radioactive isotopes between the soluble and insoluble fractions of radioactive fallout is determined by the chemical properties of the isotope, the quantity of solid phase, the type of fallout, and its physical state. The isotopes which were studied occurred in solution in the order Sr90>Cs137>C144.Although most of the radioisotopes in the soluble part of fallout are present as cations (for a l i types of fallout the averages are 59% (Ce144), 75% (Sc137) and 86% (Sr90 a considerable fraction is present in anion or neutral form. The ratio between the forms depends on the chemicaI properties of the element and the chemical composition of the solution.Radioisotopes occurring in the insoluble fraction of the fallout can also take part in the processes of migration in soil and vegetation. The greatest mobility from the solid phase is shown by Sr90 the least by Ce144.Translated from Atomnaya Énergiya, Vol. 20, No. 4, pp. 333–337, April, 1966. |