Radioactivity exploration from the Arctic to the Antarctic. Part 4: The Arctic Ocean-91 expedition

• Main Authors: Persson, Bertil R, Holm, Elis, Josefsson, Dan, Roos, Per, Carlsson, Kjell-Åke Carlsson
• Format: Article in Journal/Newspaper
• Language: English
• Published: Bertil RR Persson, Medical Radiation Physics, 22185 Lund, Sweden 2015
• Subjects: Environmental Health and Occupational Health; seawater; 239+240Pu; 137Cs; 134Cs; Arctic Ocean; M/S Oden; 7Be; 210Pb; 210Po; surface air; Arctic; Antarctic; The Antarctic; Antarc*; Nansen Basin; oden
• Online Access: https://lup.lub.lu.se/record/8515915; https://doi.org/10.13140/RG.2.1.4066.5042; https://portal.research.lu.se/files/3347811/8515962.pdf

The Arctic Ocean expedition in 1991 with the Swedish icebreaker M/S Oden was focused on oceanography and geology. The aim of our project was exploring the activity concentrations in surface air of 7Be, 210Pb. and 210Po in the surface air, radioactive isotopes of Caesium (134Cs, 137Cs) and plutonium (239+240Pu) in seawater. During the cruise in the Arctic Ocean during 1991-07-28 to 1991-10-04 the average activity concentrations in surface air of 7Be was 0.6±0.4 mBq.m-3 , 210Pb 46±34 microBq.m-3 and 210Po 37±23 microBq.m-3 The activity concentration of 137Cs in the surface of the Arctic Ocean was in the range of 8-12 Bq.m-3. When crossing the Nansen basin the activity concentration of 137Cs increased to about 18 Bq.m-3 at 88 °N 80 °E, and there was an accumulation of 137Cs in an area around at 88 °N and 80-100 °E and locally increased activity at 83 °N 10 °E. The 134Cs/137Cs activity ratios was about 0.02 due to the contribution mainly from Sellafield and a few percent contribution from Chernobyl. The 134Cs/137Cs activity ratio decreased to about 0.002-0.005 in areas of high 137Cs activity concentration which exclude contribution of 134Cs of nuclear reactor fuel. The activity concentration of 239+240Pu in the surface of the Arctic Ocean was in the range of 6 - 8 mBq.m-3. But locally the activity concentration of 239+240Pu was found to be increased to 11 mBq.m-3 at 86°N 48-53°E, and to 16 mBq.m-3 at 83°N 10°E.