Radioactivity in sediments from the Grliska impoundment

The concentrations of the fission radionuclide Cs-137, an activation radionuclide Cs-134 and the naturally occurring radionuclides K-40, Ra-226 and Th-232 were measured by gamma spectrometry in the sediment and water samples collected from the Grliska artificial lake and its tributaries. The deposition of radiocesium per square meter of sediments ranged from 2799 to 6158 Bq/m(2). The total gamma activity of sediments appeared to be due to all determined radionuclides with a major contribution of the naturally occurring radiopotassium. Activity ratio Cs-134/Cs-137 recalculated to April 1986 showed that radiocesium in the Grliska impoundment environment originated from the Chernobyl fallout. Radionuclide partitioning coefficients were calculated in order to explain their transport/retardation in the Grliska impoundment ecosystem. (UK)