IAEA-SM-354/175P XA"51422 ARTIFICIAL RADIONUCLIDE CONTENTS IN THE COASTAL REGIONS OF THE BARENTS, KARA AND WHITE SEAS

Matishov G.G., Matishov D.G., Namjatov A.A. Murmansk, Tel.: +7 (8512) 56 52 32, tel./fax: +47 789 10 288, Murmansk Marine Biological Institute, 183010, Vladimirskaya St., 17, E-mail: [email protected]

Large number of objects of radiation danger is situated in the coastal waters of the Barents, Kara and White seas, so the probability of accident connected with the leakage of artificial radionuclides into the marine ecosystem is higher here than in other areas. E.g. naval and civic ships with nuclear power installations and the attendant infrastructure are based in several inlets of the . Potentially dangerous areas of the Kara Sea are represented by the bays and inlets on the eastern coast of the Novaya Zemlya where the multitude of containers with solid radioactive wastes and also several reactors with unloaded nuclear fuel are buried. Besides, the probability of penetration of artificial radionuclides exists also for the Ob and Yenisey Bays from the sources situated in the upper parts of corresponding rivers and their tributaries. The data used for the present work were collected in the field researches in the Kola and Motovsky bays in 1995-1997, in the Bay - in 1996, in the Ob Bay of the Kara Sea - in 1996 and in the White Sea - in 1997. Besides, the earlier data collected in the international expedition of 1992 on the RV «Dalnie Zelentsy» to the Pechora Sea (that is the south-eastern part of the ) were used [1] (Fig.l). Bottom sediments mainly were sampled during these expeditions and also several water and algae samples were taken. Granulometric composition of bottom sediments was determined for the study of artificial radionuclide accumulation conditions. The content of ^^Cs in the water samples of the Kola and Motovsky Bays was from 4,7 to 8,0 Bq/cub.m and the same of ]34Cs - less than 0,3 Bq/cub.m. The content of l^Cs in the bottom sediment samples taken far from the sources of contamination varied from 1-2 Bq/kg dry weight in the sediments with the prevalence of sand (to 90%) and to 26 Bq/kg dry weight in those with the prevalence of clay and alleviate. ^Co was observed in the samples in all the area of Kola and Motovsky Bays from tracing quantities to 1-2 Bq/kg. However, the content of artificial radionuclides somewhat increases near the sources of contamination: 137Cs to 45 Bq/kg, 60Co to 27 Bq/kg. Besides, I54Eu to 123 Bq/kg and }52Eu to 55 Bq/kg were registered in the Kola Bay a short way off the basing place of atomic ice- breakers [2]. The content of artificial radionuclides in the algae (Laminaria sacharina, Fucus vesisculosus) collected along the Kola Peninsula in the Barents Sea was 0,45-2,3 Bq/kg raw weight for l^Cs [3]. It may increase 20-40 times in the near vicinity of the sources of discharge of artificial radionuclides (where the atomic ice-breakers are based). Other radionuclides discharged by these bases were observed here also. The research conducted by us revealed the real picture of impact of the radiation contamination sources on the coastal areas of the Barents, Kara and White Seas.

560 REFERENCES

1. Smith, K..M. Ellis, K. Naes, S. Dahle, D. Matishov. Sedimentation and mixing rates of radionuclides in Barents Sea sediments off Novaya Zemlya. Deep-Sea Research Part II, 1 6, pp. 1471-1493, 1995. 2. Matishov G.G., Namjatov A.A., Matishov D.G. Radioactive Contamination of sediment in the Kola Fjord near RTP «Atomflot», the base of the nuclear fleet // Reducing Wastes from Decommissioned Nuclear Submarines in the Russian Northwest. Proceedings from the NATO Advanced Research Workshop/ Kirkenes, 24-28 June 1996. p. 85-101. 3. Ikaheimonen, K. Rissanen, D.G. Matishov, G.G. Matishov. Plutonium in Fish, Algae and Sediment in the Barents, Petshora and Kara Sea. The Second International Conference on Environmental Radioactivity in the Arctic. Oslo 1995. P. 217-232.

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Barents Sea 3

White Sea

FIG.1. Areas of investigations in the Barents, Kara and White Sea.

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