Ядерна фізика та енергетика Nuclear Physics and Atomic Energy   ISSN: 1818-331X (Print), 2074-0565 (Online)   Publisher: Institute for Nuclear Research of the National Academy of Sciences of Ukraine   Languages: Ukrainian, English   Periodicity: 4 times per year   Open access peer reviewed journal

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B. Yu. Zanoz^*, D. O. Bugai

Institute of Geological Sciences, National Academy of Sciences of Ukraine, Kyiv, Ukraine

^*Corresponding author. E-mail address: bzanoz@gmail.com

Abstract: Modeling predictions are presented of radionuclide transport processes in the zone of influence of the Zahidne uranium mill tailings situated at the Prydniprovsky Chemical Plant (PChP), Kamianske. The groundwater transport model was developed using the NORMALYSA software. Refined estimates of parameters of water exchange in the zone of uranium mill tailing (obtained from field studies and modeling of groundwater flow processes) were used to parameterize the model for radionuclide transport in groundwater. Calibration of the radionuclide transport model using monitoring data on radioactive contamination of groundwater in 2005 - 2021 allowed to estimate the sorption distribution coefficient (Kd) for the most hazardous contaminants ^238,234U isotopes (Kd = 8 ± 2 l/kg) and estimate the rate of uranium migration in groundwater. According to modeling, during the next 800 to 1100 years, uranium concentration in wells in the zone of influence of uranium mill tailing (at 500 - 800 m distance) will be determined mainly by the contamination of the alluvial aquifer, which was formed during the operation period of the uranium mill tailing. According to modeling predictions, usage of groundwater (partial drinking water consumption, irrigation) outside the PChP site downstream of the uranium mill tailing will result in doses exceeding the relevant reference level (annual effective dose > 1 mSv/year) in 380 - 440 years, while the toxicological impact will result in the exceeding of the acceptable hazard index for uranium (HI > 1) in 200 - 260 years. Modeling results indicate the importance of restricting the use of groundwater downstream of the uranium mill tailing within the PChP industrial site and, in the longer term, beyond its boundary. At the same time, contamination of the Konoplyanka River due to the migration of radionuclides from the uranium mill tailing does not pose unacceptable radiological and toxicological risks for the considered scenario (irrigation, fish consumption) due to the dilution of contaminants in surface waters.

Keywords: groundwater, groundwater modeling, Prydniprovsky Chemical Plant, risk assessment, uranium.

1. F.P. Carvalho. Environmental radioactive impact associated to uranium production. American Journal of Environmental Sciences 7(6) (2011) 547. https://doi.org/10.3844/ajessp.2011.547.553

2. P. Byrne et al. Transport and speciation of uranium in groundwater-surface water systems impacted by legacy milling operations. Science of the Total Environment 761 (2021) 143314. https://doi.org/10.1016/j.scitotenv.2020.143314

3. Yu.I. Kuzovov. Pridneprovskiy Chemical Plant (Historical Review) (Dnepropetrovsk: Poligrafist, 1997) 160 p. (Rus).

4. T. Lavrova, O. Voitsekhovych. Radioecological assessment and remediation planning at the former uranium milling facilities at the Pridnieprovsky Chemical Plant in Ukraine. Journal of Environmental Radioactivity 115 (2013) 118. https://doi.org/10.1016/j.jenvrad.2012.06.011

5. E. Tkachenko et al. Monitoring of technogenic contamination of groundwater and surface water in the zone of influence of uranium tailings of the Pridneprovsky Chemical Plant (Kamyanske). Geological Journal (Ukraine) 3 (2020) 17. (Ukr) https://doi.org/10.30836/igs.1025-6814.2020.3.206341

6. D.O. Bugai et al. Development of the groundwater monitoring system in the zone of influence of uranium production legacy facilities of the Prydniprovsky Chemical Plant. Geological Journal (Ukraine) 4 (2021) 56. (Ukr) https://doi.org/10.30836/igs.1025-6814.2021.4.240111

7. B. Zanoz, K. Tkachenko, D. Bugai. Analysis of hydrogeological and geochemical factors of migration of radionuclides and toxic metals from uranium tailings to groundwater. Collection of Scientific Works of the Institute of Geological Sciences NAS of Ukraine 14(2) (2021) 83. (Ukr) https://doi.org/10.30836/igs.2522-9753.2021.245705

8. T. Lavrova, K. Korychenskyi, O. Voitsekhovych. Assessment of temporal and space-time changes of groundwater chemical composition at the "Рridniproivsky chemical plant" uranium production legacy site. Hydrology, Hydrochemistry and Hydroecology 4 (66) (2022) 81. (Ukr) https://doi.org/10.17721/2306-5680.2022.4.9

9. O. Skalskji et al. Groundwater monitoring data and screening radionuclide transport modeling analyses for the uranium mill tailings at the Pridneprovsky Chemical Plant Site (Dneprodzerzhinsk, Ukraine). In: B. Merkel, M. Schipek (Eds.). The New Uranium Mining Boom. Challenge and Lessons Learned (Berlin, Heidelberg: Springer, 2011) p. 219. http://dx.doi.org/10.1007/978-3-642-22122-4_26

10. S. Pepin et al. Intermodel comparison for the radiological assessment of the Zapadnoe and Tessenderlo case studies with implications for selection of remediation strategy. Journal of Radiological Protection 42(2) (2022) 020510. https://doi.org/10.1088/1361-6498/ac66a4

11. B.Yu. Zanoz, D.O. Bugai. Determination of parameters of water exchange and modelling of groundwater flow process for uranium mill tailings "Zahidne" of the Prydniprovsky Chemical Plant. Collection of Scientific Works of the Institute of Geological Sciences NAS of Ukraine 16(1) (2023) 98. (Ukr) https://doi.org/10.30836/igs.2522-9753.2023.291210

12. B. Zanoz, et al. Assessment of radiological and toxicological risks from the use of groundwater and surface water in the zone of influence of the uranium production legacy site. Nucl. Phys. At. Energy 23 (2022) 271. https://doi.org/10.15407/jnpae2022.04.271

13. V. Protsak et al. Evaluation of the parameters of migration of the uranium series radionuclides in the tailings of the Pridneprovskiy chemical plant. Nucl. Phys. At. Energy 14 (2013) 55. (Ukr) https://jnpae.kinr.kyiv.ua/14.1/Articles_PDF/jnpae-2013-14-0055-Protsak.pdf

14. D. Bugai et al. Analysis of spatial distribution and inventory of radioactivity within the uranium mill tailings impoundment. Nucl. Phys. At. Energy 16 (2015) 254. https://doi.org/10.15407/jnpae2015.03.254

15. D. Rudakov et al. A predictive assessment of the uranium ore tailings impact on surface water contamination: Case study of the city of Kamianske, Ukraine. Journal of Environmental Radioactivity 268-269 (2023) 107246. https://doi.org/10.1016/j.jenvrad.2023.107246

16. User Manual for NORMALYSA v.2.3. Description of Program Module Libraries, Mathematical Models and Parameters. Modelling and Data for Radiological Impact Assessments (MODARIA) Programme, IAEA-TECDOC-2037 (Vienna: International Atomic Energy Agency, 2023) 223 p. https://www-pub.iaea.org/MTCD/publications/PDF/TE-2037web.pdf

17. D. Ene et al. Assessment of environmental consequences of the normal operations of the ESS facility. Journal of Physics: Conference Series 1046 (2018) 012018. https://doi.org/10.1088/1742-6596/1046/1/012018

18. Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards. IAEA Safety Standards Series No. GSR Part 3 (Vienna: International Atomic Energy Agency, 2014) 436 p. https://www-pub.iaea.org/mtcd/publications/pdf/pub1578_web-57265295.pdf

19. Remediation Strategy and Process for Areas Affected by Past Activities or Event. IAEA Safety Standards Series No. GSG-15 (Vienna: International Atomic Energy Agency, 2022) 201 p. https://www-pub.iaea.org/MTCD/Publications/PDF/PUB1969_web.pdf

20. D. Bugai et al. Safety ranking of Chernobyl radioactive legacy sites situated in populated areas for prioritization of remedial measures. Nucl. Phys. At. Energy 20 (2019) 34. https://doi.org/10.15407/jnpae2019.01.034

21. F.P. Carvalho et al. The environmental behavior of uranium. Technical Reports Series No. 488 (Vienna: International Atomic Energy Agency, 2023) 378 p. https://www-pub.iaea.org/MTCD/publications/PDF/PUB_DOC_488_web.pdf

22. Risk Assessment Guidance for Superfund. Vol. I. Human Health Evaluation Manual (Part A) (Washington, D.C.: U.S. Environmental Protection Agency, 1989) 291 p. https://www.epa.gov/sites/default/files/2015-09/documents/rags_a.pdf

23. C. Baes III, R. Sharp. A proposal for estimation of soil leaching and leaching constants in assessment models. Journal of Environmental Quality 12(1) (1983) 17. https://doi.org/10.2134/jeq1983.00472425001200010003x

24. Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Terrestrial and Freshwater. IAEA Technical Report Series No. 472 (Vienna: International Atomic Energy Agency, 2010) 194 p. https://www-pub.iaea.org/mtcd/publications/pdf/trs472_web.pdf