1) To perform simulation scenarios for the 21st century, including global warming scenarios, of potential radioactive spreading from sources in the Russian Arctic coastal zone and its impact on Barents, Greenland and Norwegian Seas and the Arctic Ocean; 2) To update the environmental and pollution data base of the Arctic Monitoring and Assessment Program (AMAP); 3) To assess, select and define the most probable simulation scenarios for accidental releases of radionuclides; 4) To implement a Generic Model System (GMS) consisting of several nested models designed to simulate radionuclides transport through rivers, in the Kara sea and in the Arctic ocean / North Atlantic; 5) To carry out simulation studies for the selected "release" scenarios of radionuclides, using various atmospheric forcing scenarios; 6) Assess the impact on potential radioactive spreading from sources as input to risk management.