Development of a fast method for the determination of SR-89 and SR-90 in soil samples an its application to the determination of SR-90 in Ukrainian soils

A fast method for the determination of Sr-90 and Sr-89 in soil samples is developed. Radio-chemical separation of Strontium is achieved by combination of precipitation reactions and extraction-chromatography. Sr-90 and Sr-89 activities are measured by liquid scintillation counting. The new method is applied to determine the Sr-90 activities of Ukrainian soils. Soil profiles taken at Zhitomir, 150 km southwest of Pripjat, and Charkow, 450 km southeast of Pripjat showed deposition densities of 1.7 kBq m(-2) (26.04.86) which is about the background of the nuclear fallout from the sixties. Soils from the region of Korosten, 110 km southwest of Pripjat, showed deposition densities between 3.0 and 5.7 kBq m(-2). The higher contamination level is due to the fallout from the Chernobyl accident. More then 90 % of the total activity of Sr-90 is still retained within the upper 25 cm in all profiles.