Environmental assessment of the marine area in the vicinity of a nuclear submarine accident in the Chazma Bay (Primorsky Krai). S.M. KISELEV, Yu.N. ZOZUL, T.N. LASCHENOVA, V.V. SHLYGIN, D.V. ISAEV, S.V. AHROMEEV, A.N. MALAKHOVA

Abstract

Environmental assessment of the marine area in the vicinity of a nuclear submarine accident in the Chazma Bay (Primorsky Krai). S.M. KISELEV¹, Yu.N. ZOZUL¹, T.N. LASCHENOVA^{1, 2}, V.V. SHLYGIN¹, D.V. ISAEV¹, S.V. AHROMEEV¹, A.N. MALAKHOVA¹ (¹Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow, ²Peoples’ Friendship University of Russia, Moscow).

Thirty-five years ago, there was a nuclear accident on a nuclear submarine in the Chazhma Bay (Fokino, Primorsky Krai). The FMBA of Russia carries out supervision of radiation safety of the community in these territories. This article presents the results of long-term studies of the state of pollution of the sea area of the Chazhma Bay, the flooded dock (freshwater reservoir) located near the ship repair plant (30 SRZ). Objects of the aquatic ecosystem are characterized by residual contamination with radionuclides – ⁶⁰Co, ²³⁵U, ¹³⁷Cs, among which ⁶⁰Co is the main one. There are local areas of the water area identified where the specific activity of 60Co in bottom sediments exceeds the established levels for unrestricted use of materials in economic activities. They include the locations of ⁶⁰Co in the area of the former emergency piers of 30 SRZ and the flooded dock along the axis of the trace distribution, ¹³⁷Cs in the area of the former location of the ships of the administrative-territorial unit (ATU) at the territories of the facility for long-term storage of reactor compartments (LTS RC, Ustrichny Cape). The content of ²³⁵U in the bottom sediments of the sea area and the flooded dock slightly exceeds the background values but does not exceed the established levels for unrestricted use of materials in economic activities. The specific activity of ⁶⁰Co, ²³⁵U, ¹³⁷Cs in seawater and water of the flooded dock meets the requirements for coastal waters of the seas in water consumption areas for people. Excess of MPC of heavy metals (Pb – 5 MPC, As – 3 MPC, Be – 6 MPC) in seawater, as well as in territories used by the population for recreational purposes. In general, the ecological situation in the sea area of Chazhma Bay is normal and does not require remediation and public access restriction to these areas. At the same time, it is necessary to monitor periodically water and biota objects that can be used by the population, especially in the water area of a flooded dock.