Modeling the transport of radioactive contaminants in the arctic

Abstract

A coupled ice-ocean model, designed by the Naval Research Laboratory, composed of the Cox ocean model coupled to the Hibler ice model is used to simulate the dispersion of radioactive contaminants in the Arctic and its marginal seas. Source locations and estimated inventories of disposed radionuclides are based on those documented in a Russian report referred to as the Yablokov Report. The ocean model is separated from the ice model to investigate only the transport and dispersion of contaminants once they have entered the water column. Several 10-year model simulations are presented using the following sources: (1) low level solid and liquid radioactive wastes dumped in both the Kara and Barents Seas; (2) higher level radioactive wastes, including marine reactors with spent nuclear fuel dumped along the Novaya Zemlya coast in the Kara Sea; (3) river discharge carrying radioactive wastes into the Kara and Barents Seas; and (4) radioactive wastes discharged from the nuclear fuel reprocessing plant at Sellafield in the Irish Sea. Comparison of these model results to data indicates that both the riverine and the Sellafield sources can account for the levels of radioactivity (approximately 10 1 Bq/m 3) recently observed in the Kara Sea. When the discarded marine reactors are used as the source in the model, levels of radioactivity are an order of magnitude higher than observed, implying that these radioactive wastes are still well encased and not leaking significantly into the water column.