Anthropogenic radionuclides in Kola and Motovsky Bays of the Barents Sea, Russia

Russia’s military and civilian nuclear powered maritime fleets operate in the Kola and Motovsky Bays on the northwest Arctic coast of Russia. Levels of anthropogenic radionuclides were measured in sediment grab samples collected from approximately 100 stations in areas near military and civilian nuclear installations and in the open waters of the two bays. In most areas, radionuclide levels are similar to those reported for other Arctic seas: 137Cs=1–24 Bq kg-1 d.w., 60Co=<1 Bq kg-1 d.w. and 239,240Pu=0.8–1.6 Bq kg-1 d.w. However, the presence of 60Co (up to 27 Bq kg-1 d.w.) indicates that minor leakage of radioactive waste has occurred near several military installations. Sites where leakage is detected include Pala, Sayda, Olenya and Ekaterininskaya Bays in the Kola Bay and Zapadnaya Litsa in Motovsky Bay. 137Cs levels of 40–50 Bq kg-1 d.w. and 239,240Pu levels of up to 2.2 Bq kg-1 d.w. were measured near several military installations but these levels do not indicate leakage as the source. Some of the highest 60Co activities were detected in sediments collected near the civilian nuclear installation, Atomflot. The sediments also contained higher 137Cs activities compared to samples from other regions of the study area with similar particle size distributions. Routine discharges of purified radioactive waste from the Atomflot facility are the likely source of 60Co and enhanced 137Cs levels. With this investigation, we have detected evidence of radioactive waste leakage in the marine environment, but the environmental impact on the bays has been minimal.