The transfer of reprocessing wastes from north-west Europe to the arctic

The discharge of radioactive waste, from nuclear fuel reprocessing facilities, into the coastal waters of north-west Europe has resulted in a significant increase in the inventories of a number of artificial radionuclides in the North Atlantic. Radiocaesium, Sr-90 and Tc-99, which behave conservatively in seawater, have been used widely as tracers of water movement through the North Sea, Norwegian Coastal Current, Barents Sea, Greenland Sea, Fram Strait, Eurasian Basin, East Greenland Current and Denmark Strait overflow. These studies are summarised in the present paper. It has been estimated that 22% of the Cs-137 Sellafield discharge has passed into the Barents Sea, en route to the Nansen Basin, via the Bjornoya-Fugloya Section, with another 13% passing through the Fram Strait. This amounts to 14 PBq Cs-137. Quantifying the influx of other radionuclides has been more problematic. The inflowing Atlantic water now appears to be diluting waters in the Arctic Basin, which were contaminated in the late 1970s and early 1980s as a result of the substantial decrease in the discharge of reprocessing wastes. Sellafield (U.K.) has dominated the supply of Cs-134, Cs-137, Sr-90, Tc-99 and Pu, whereas La Hague (France) has contributed a larger proportion of I-129 and Sb-125.