ACCUMULATION OF CS-137 AND SR-90 BY PLANTS IN THE FALLOUT AREA AT THE SEMIPALATINSK TEST SITE

The article presents data on the content and assessment of parameters of artificial ¹³⁷Cs and ⁹⁰Sr accumulation by steppe motley grasses in the fallout area in borehole 101 of the former ‘Sary-Uzen’ testing site of the Semipalatinsk Test Site (STS). ¹³⁷Cs activity concentration in land cover of the study area was found to reach 2,700 Bq/kg, ⁹⁰Sr – up to 3,370 Bq/kg. The ranges of Tf values for ¹³⁷Cs (0.0030-0.021) and ⁹⁰Sr (0.064-0.36) are one order of magnitude each. ⁹⁰Sr is most accumulated in plants. Its Tf maxima are noted in the dump zone of the explosion crater. No Tf variation dependences on the distance from ground zero were found for either radionuclide. At the same time, Tf values are one order of magnitude higher than the ones previously obtained for ground zeros of aboveground nuclear tests and one order of magnitude lower than Tf values for these radionuclides obtained as a whole for pastures as reported by IAEA.

1. Vernadsky, V. I. Selected works: in 5 vol. / ed-in-chief, academician. А. P. Vinogradov; USSR Academy of Sciences. – Moscow: Publishing House of AS USSR, 1960. – Vol. 5: Biosphere I-II: Biogeochemistry articles; Sols; Gases; Meteorites and cosmic dust. – 1960. – 422 p.

2. Timofeev-Resovsky, N. V. Selecta / N. V. Timofeev-Resovsky; edited by O. G. Gazenko and V. I. Ivanov. – Moscow: Medicine, 1996. – 480 p. – ISBN 5-225-00773-2.

3. Aleksakhin, R. M. Agricultural radioecology: In the book on Agroecology. – Moscow: Kolos, 2000. – P. 300–322.

4. Sanzharova, N.I. Revision of parameters of radionuclide migration in agroecosystems / N. I. Sanzharova, S. V. Fesenko, A. O. Shubin // Radiation biology. Radioecology. – 2009. – No. 3. – P. 268–276.

5. Natalia Semioshkina, Gabriele Margarete Voigt Soil - Plant transfer of radionuclides in arid environments // Journal of Environmental Radioactivity. – 2021. – Vol. 237, 106692.

6. Nuclear tests of the USSR. The Semipalatinsk Test Site: general and radiation safety assurance during nuclear tests / contributed authors supervised by V. A. Logachev. – Moscow: 2nd printing house FA “'Medbioekstrem” under the Russia Ministry of Healthcare, 1997. – 347 p. – ISBN 5-88918-008-8.

7. Larionova, N.V. Transfer of radionuclides to plants of natural ecosystems at the Semipalatinsk Test Site / N. V. Larionova, S. N. Lukashenko, А. М. Kabdyrakova [at al.] // Journal of Environmental Radioactivity. – 2018. – No. 186. – Р. 163–170.

8. Krivitskiy, P.Ye. Characterization of area radioactive contamination of near-surface soil at the Sary-Uzen site in the Semipalatinsk test site / P. Ye. Krivitskiy, N. V. Larionova, Yu. V. Baklanova, А. O. Aidarkhanov, S. N. Lukashenko // Journal of Environmental Radioactivity. – 2022. – No. 249 – 106893.

9. Activities of radionuclides in bulk samples. Measurement procedure with a gamma spectrometer: MP 2143-91: MP 5.06.001.98 RK. – Almaty, 1998. – 18 p.

10. Determination procedure of the content of artificial radionuclides plutonium-(239+240), strontium-90 in environmental compartments (soils, bottom sediments and plants). – Almaty, 2010. – 25 p.

11. Quantification of radionuclide transfer in terrestrial and freshwater environments for radiological assessments: IAEA TECDOC-1616/ IAEA. – Vienna, 2009. – 163 p. – ISBN 978–92–0–104509–6.

12. Larionova, N.V. Transfer parameters of radionuclides from soil to plants at the area of craters produced by underground nuclear explosions at the Semipalatinsk test site areas / Larionova, N.V., S.N. Lukashenko, O.N. Lyakhova [at al.] // Journal of Environmental Radioactivity. – 2021. – No. 237. https://doi.org/10.1016/j.jenvrad.2021.106684