GRNTI 34.49 Радиационная биология
Purpose: Assessment of the radiation situation at the tailing dump of the Stepnogorsk Mining-Chemical Combine (SMCC) and the settlements around. Material and methods: The tailing dumps of the SMCC and the settlements near located of Aksu, Kvartsytka and Zavodskaya were objects of the radioecological research. Field expedition studies were performed during the summer period and consisted in carrying out a detailed gamma survey of the territory of the investigated objects and settlements, sampling of surface waters, vegetation, surface and layered soil samples. In settlements, along with sampling and studying the gamma background, the equivalent equilibrium volume activity of radon daughters in residential and industrial premises was determined. To determine the concentrations of the studied radionuclides a background was selected, within which the levels of their global deposition were studied. To calculate the individual effective radiation dose of the population the National Radiation Protection Board methodology was used as the basis. Results: In the northern part of the tailing dump of the SMCC in the adjoining territory, a radioactive contamination site was found where the specific activity values for 226Ra, 232Th and 210Pb reach values of 1500–2000 Bq/kg. On the territory of the Aksu settlement, 5 local areas with the area from 25 to 1000 m2 were found, with the intensity of ambient dose equivalent of gamma radiation from 0.39 to 0.86 µSv/h. In the Zavodskaya village, two areas with increased levels of gamma radiation intensity were identified. Conclusion: The obtained results of field work and laboratory analytical studies testify to the negative impact of the tailing dump of the SMCC on the environment of adjacent territories, expressed in contamination of soil, water and vegetation with radionuclides. The nature of the abnormal areas on the territory of the settlements of Aksu and Zavodskaya excludes their origin from the tailing dump of the SMCC. The appearance of these areas of contamination may be due to the use of materials of the 3rd class in sanitary and hygienic standards for improvement and road construction. The probable annual effective dose for the population living in the radioactive local areas of the Aksu ~6.5 mSv/year, at the normal rate of 1 mSv/year from man-made radiation sources.
uranium, gamma radiation, intensity of ambient dose equivalent, equivalent equilibrium volumetric activity of radon, radionuclides, mining-chemical combine
Техногенное загрязнение окружающей среды радионуклидами в процессе добычи и переработки полезных ископаемых является проблемой многих стран, включая Казахстан, которые обладают месторождениями природного урана и других минералов. В результате деятельности уранодобывающих предприятий в Республике Казахстан (РК) накоплено более 170 млн тонн радиоактивных отходов, которые требуют постоянного радиационного контроля, а также реабилитации территории [1, 2]. При этом только в северном регионе скопилось около 61 млн тонн радиоактивных отходов с общей суммарной активностью 168,4 тыс. кюри [3]. В 2001–2008 гг. были проведены работы по консервации и ликвидации урановых месторождений в указанном регионе [4]. В настоящее время в РК используются несколько хвостохранилищ радиоактивных отходов. Крупнейшим среди них является хвостохранилище Степногорского горнохимического комбината (СГХК), функционирующего с 1956 г. Основными видами производственных отходов СГХК являются хвосты переработки урановых руд, которые по содержанию в них радионуклидов относятся к I классу опасности [5]. В доступной литературе имеется ряд исследований по радиационной обстановке и оценке радиационного риска для персонала в уранодобывающих предприятии. Публикаций, посвященных оценке риска для населения, проживающих в зоне действия хвостохранилища радиоактивных отходов, немного [6, 7].
1. Kazymbet P.K., Seisebaev A.T. Problems of the complex assessment of radiobioecological situation and public health in uranium-extraction region of Kazakhstan // 2002. T. 42. № 6. P. 750–753.
2. Yazikov V.G. Uranium Resources of the Republic of Kazakhstan // Uran i Yadernaya Energetika (‘Uranium and Nuclear Power’). – London. 1993. P. 132–1137. (In Russian)
3. Yazikov V.G. Geological and industrial types of uranium deposits of the Republic of Kazakhstan and prospects of entering the world market. – Moscow: Diss. Cand. Geol.–mineral. 1995. 65 pp. (In Russian)
4. Decree of the Government of the Republic of Kazakhstan «On approval of the Conservation Program for uranium mining enterprises and liquidation after the development of uranium deposits for 2001–2010»: approved on July 25, 2001 No. 1006 // Lawyer-reference legal system. 2002. (In Russian)
5. http://www.kazatomprom.kz/ru/content/kompaniya/deyatelnost/dobycha-prirodnogo-urana (12.04.2017)
6. Kazymbet P.K., Imasheva B.S., Bakhtin M.M. Radioecological state of natural objects around uranium mining enterprises of Akmola region // Med. Radiol. i Radiats. Bezopasnost’ (‘Medical Radiology and Radiation Safety’). 2006. Vol. 53. № 3. P. 22–27. (In Russian)
7. Kazymbet P.K., Bakhtin M.M., Imasheva B.S. Estimation of the effective dose from external exposure of the population of some regions of Northern Kazakhstan // Astana medical journals. 2006. № 4. P. 12–19. (In Russian)
8. Oatway W.B., Mobbs S.F. Methodology for estimating the doses to members of the public from the future use of land previously contaminated with radioactivity. – NRPB, Chilton. 2003. 145 pp.
9. Evaluation of individual effective doses of population exposure due to natural sources of ionizing radiation. Methodological Guidelines. 2.6.1.1088-02. M. 2002. 22 pp. (In Russian)
10. United Nations. Sources and Effects of ionizing radiation. United Nations Scientific Committee on the Effects of Atomic Radiation. 1993 Report to the general assembly, with annexes. United Nations sales publication E.88.IX.7. – United Nations. New York. 1993
11. Sources and effects of ionizing radiation. UNSCEAR 2000 Report to the General Assembly with scientific annexes. – Moscow: RADEKON. 2002. Vol. 1. 216 pp. (In Russian)
12. Materials of the work of the Commission for studying the state of radiation situation at the mining plant administration of the Tselinny Mining-Chemical Combine. – Almaty: Atomic Energy Agency of the Republic of Kazakhstan. 1993. 20 pp. (In Russian)
13. Sevostyanov V.N. The problem of radon safety in Kazakhstan. – Almaty. 2004. 212 pp. (In Russian)
14. Efremov G.F. Hydrogeological survey of cretaceous-paleogenic aquifers used for domestic and drinking water supply in the Suzaksky District of the South Kazakhstan Region for the purpose of assessing contamination with radionuclides (program 46, subprogramme 30): report of the environmental party CGE-39. – Almaty: JSC Volkovgeology. 2001. 76 pp. (In Russian)
15. Berikbolov B.R. Elimination and conservation of 32 self-draining wells with increased radionuclide content in the territory of the Suzak region of the South Kazakhstan Region: JSC Volkovgeology report. – Almaty. 2002. 272 pp. (In Russian)
16. Sanitary rules «Sanitary-epidemiological requirements for ensuring radiation safety». Decree of the Government of the Republic of Kazakhstan №. 202 of 03.02.2012. (In Russian)
17. Kazymbet P.K., Imasheva B.S. The content of radionuclides and heavy metals in milk of cattle from uranium-mining regions of Northern Kazakhstan // Astana medical journals. 2005. № 3. P. 18–21. (In Russian)
18. Imasheva B.S. Ways of transition of natural radionuclides and heavy metals along food chains in uranium-mining regions // Bulletin of Science of Saken Seifullin Kazakh AgroTechnical university2007. № 4 (47). P. 160–164 (In Russian)
19. Methodological guidance on radioecology and radioactive waste management for the conditions of the Republic of Kazakhstan. – Almaty. JSC Volkovgeology. 2002. 306 pp. (In Russian)
