Benchmarking of numerical models describing the dispersion of radionuclides in the Arctic Seas

Modelling the radioactive contamination of commercial fish species in the Barents Sea following a hypothetical short-term release to the Stepovogo Bay of Novaya Zemlya

A dynamic modelling of radionuclides accumulation in commercial species in the Barents Sea is performed for hypothetical SCR accident with the dumped submarine K-27 at the Stepovogo Bay. Box radioecological model is employed for calculating the radionuclides dynamics in water, bottom sediments and marine biota. The model takes into account the seasonal fish migrations in the Barents Sea. The model allows predicting the dynamic effects of the radionuclide transfer in fish in case of an accidental water contamination. Maximum ¹³⁷Cs activity concentrations in bottom sediments from the eastern part of the Barents Sea could be reached as late as 5-6 years after the accidental release. Based on the results of model calculations, assessment was made of doses to humans from consumption of seafood contaminated after a hypothetical SCR accident with K-27 at the Stepovogo Bay. The peak activity concentration of the released ¹³⁷Cs in fish from the Stepovogo Bay is calculated to be 109 Bq∙kg^-1, ⁹⁰Sr - 12 Bq∙kg^-1; both estimates are below the permissible activity concentrations of these radionuclides in commercial fish. Predicted maximum annual dose from consumption of fish from the Stepovogo Bay is 47 ± 18 μSv∙year^-1, the Barents Sea fish - less than 3∙10^-6 μSv∙year^-1.¹³⁷Cs is the major dose contributor; it provides more than 99% to the annual dose Radiation risks from consumption of the Barents Sea commercial fish are evaluated to be negligible in case of a hypothetical SCR accident with the submerged submarine K-27 in Stepovogo Bay of Novaya Zemlya.