Dispersal of the radionuclide caesium-137 (137Cs) from point sources in the Barents and Norwegian Seas and its potential contamination of the Arctic marine food chain: Coupling numerical ocean models with geographical fish distribution data

•The dispersal of 137Cs from the wrecks of Komsomolets and K-159 are simulated.•The submarine wrecks are resting on the seabed in the Norwegian and Barents Seas.•Both realistic rates of discharges and what-if scenarios are simulated.•Concentrations of 137Cs are estimated in observational records of cod and capelin.•Only pulse discharges from K-159 causes high 137Cs concentrations in cod and capelin.

Dispersal of 137Cs from the nuclear submarine wrecks Komsomolets and K-159, which are resting on the seabed in the Norwegian and Barents Seas, respectively, is simulated using realistic rates and hypothetical scenarios. Furthermore, spatiotemporal 137Cs concentrations in Northeast Arctic cod and capelin are estimated based on survey data. The results indicate that neither continuous leakages nor pulse discharges will cause concentrations of 137Cs in cod muscle or whole body capelin exceeding the intervention level of 600 Bq/kg fw. Continuous leakages from Komsomolets and K-159 and pulse discharges from Komsomolets induced negligible activity concentrations in cod and capelin. A pulse discharge of 100% of the 137Cs-inventory of K-159 will, however, result in concentrations in muscle of cod of above 100 times the present levels in the eastern Barents Sea. Within three years after the release, 137Cs levels above 20 Bq/kg fw in cod are no longer occurring in the Barents Sea.