Experimental studies on the radionuclide migration in the Arctic Ocean

The following project tasks and results are reported in brief: Examination of interactions between sediment/ocean/sea ice at radioactive waste dumping sites in the Kara Sea, or in neighbouring sea areas with comparable oceanographic conditions. Identification of signaling sediment material (quantitative and qualitative sample composition, mineralogy, grain size distribution of the silt fraction) in surface sediments, (re)suspended particles, and inclusions in sea ice, in order to reconstruct large-area migration pathways of possibly radioactive and contaminated sediments. Description and quantification of the mechanisms leading to resuspension of sediments, their incorporation into the locally formed sea ice, and their transport and diffusion in the Arctic Ocean, accompanied by numerical model simulations of local and regional ice drifts. Quantification of potential exporting routes of radionuclides, with the sea ice from the Kara Sea formed in the 'flaw leads', and assessment of potential radiological hazards in the areas where the ice melts (Barents Sea), due to release of radioactive particles (in preparation). Quantification of possible radionuclide migration due to entrainment by salt-rich seawater released through ice melting in the 'flaw leads' (in preparation). (orig./CB)