Radioactive contamination of bukhtas and bays on the Kola Peninsula and Novaya Zemlya and in the Far East

Abstract

The characteristics of the radioactive contamination of bukhtas and bays are determined: the nonuniformity of the radionuclide distribution in the water and bottom deposits, the rate of accumulation of sediments, the distribution ratio, and the turbulent diffusion coefficient. A characteristic feature is the strong nonuniformity of the radionuclide distribution in bottom sediments. A mathematical model is proposed for radionuclide transport and water of bukhtas taking account of flow, turbulent diffusion, and settling of suspensions. Possible explanations are proposed for the characteristics of the radionuclide distribution in bukhtas. The reason for weak turbulent diffusion in bukhtas is examined.The sources of radioactive contamination of bukhtas and bays are radiation accidents, radwastes, and work performed by enterprises to refuel nuclear powered submarines and salvage and store the cores. There are many works, containing actual data and their analysis, on the radioactive contamination of bays and bukhtas [1][2][3][4][5][6][7]. Summary works which present a quite complete picture of the contamination of seas and oceans bordering our country have been published in the last few years [8,9]. These works present data on the sources of contamination and the radionuclide content in the water and bottom deposits in 22 bukhtas and bays in the Arctic and Far-East regions. Nine bukhtas are on the Kola Peninsula, four are on Novaya Zemlya, seven are in Primorskii krai, and two are on Kamchatka. The radioactive contamination of most bukhtas and bays in the Far East and on the Kola Peninsula is due to the operations of enterprises which support the functioning and salvaging of nuclear powered submarines. Reactors of nuclear powered submarines and containers with solid radwastes have been dumped in the bays on Novaya Zemlya. Radiation accidents have occurred in the bukhtas Chazhma and Pavlovskogo in Primorskii krai. For a long time, cores were refueled afloat in bukhta Bol'shoi Kamen'.The purpose of the present work is to analyze, classify, and generalize the data on the radioactive contamination of bukhtas [1-4, 8, 9]. The salient features of the radionuclide distribution in the water and bottom deposits have been determined and expressed in a quantitative form. These features are associated with the physical and chemical properties of the radionuclides and with hydrophysical processes in bukhtas. A mathematical model of radionuclide transport has been developed to explain certain features.With respect to radionuclide transport, a bukhta is an example of the system water-suspension-bottom deposits, where with time the content of the inflowing radionuclides is redistributed between the components of the system. Radionuclide transport occurs in the water by means of turbulent diffusion and advection. Radionuclides flow from the water into the bottom deposits by means of settling of suspensions and bioagitation [6,7]. These two processes are slow and, as a rule, take years [6]. Another process, characteristic for transport ...