CURRENT LEVELS OF RADIONUCLIDE CONTAMINATION IN WATER BODIES AT THE TELKEM TEST SITE

The paper provides data from the comprehensive studies of the levels and distribution pattern of radionuclide contamination in the ‘bottom sediments/soil-to-water-to-plants’ of water bodies at the Telkem site of the Semipalatinsk Test Site (STS). Research objects were water-filled craters Telkem-1 and Telekm-2 that resulted from excavation explosions. As part of these studies, sediments, soil, water, plants were duplicately sampled, in which the content of manmade 90 Sr, 239+240 Pu and g-emitting radionuclides were determined. As a result, a high level of radioactive contamination is currently found to persist in the ecosystem of water bodies at the Telkem site both for sediments ( 137 Cs, 241 Am, 90 Sr and 239+240 Pu) and water ( 90 Sr). Based upon findings, the distribution coefficient (K d ) for the ‘sediments-to-water’ system and the concentration ratio (CR s-b ) were calculated for the ‘sediments/soil-to-plants’ system. The distribution coefficient K d for 90 Sr averages 10, for 239+240 Pu – 3.7·10 5 . Plants’ capacity to accumulate from sediments and soil of aquatic ecosystems at the Telkem site, with respect to man-made radionuclides, decreases in the series C Rs-b 90 Sr > CR s-b 60 Co > CR s-b 137 Cs > CRs-b 152 Eu > CR s-b 241 Am > CR s-b 239+240 Pu.