I. O. Kovalenko1, M. I. Panasiuk1, N. V. Sosonna1,
G. V. Levin1, P. А. Lushnia1, G. K. Roienko1,
L. A. Palamar1, M. G. Buzynnyi2, I. P. Оnyshchenko3
1 Institute for Safety Problems of Nuclear Power Plants, NAS of Ukraine, 36a, Kirova st., Chornobyl, 07270, Ukraine
2 SI “O. M. Marzieiev Institute for Public Health”, National Academy of Medical Sciences of Ukraine, 50, Hetman Pavlo Polubotok (Popudrenko) st., Kyiv, 02094, Ukraine
3 SI “Radioenvironmental Centre of the NAS of Ukraine”, 55b, O. Honchara st., Kyiv, 01601, Ukraine
DOI: doi.org/10.31717/2311-8253.23.1.5
Abstract
Thermodynamic modeling of 90Sr migration was performed based on data from monitoring studies on well 4-G, which, before its liquidation in 2008, was located on the industrial site of the Chornobyl nuclear power plant. The study of the 90Sr migration forms was carried out using a set of software tools “Geochemist’s Workbench Community Edition”. In order to confirm and understand the migration processes, modeling of the spread of various complex 90Sr compounds such as SrCO3, SrHCO3, SrSO4, SrOH+ and SrNO3 + with groundwater was carried out. With the help of SpecE8, the calculation of various forms of 90Sr was performed, and the ionic strength of the groundwater solution (ISS) was also calculated. In the range of pH 9.5–12.4, there is an increase in the Sr2+ concentration in groundwater by 200–500 times to 550 Bq/l. In the same pH interval, according to thermodynamic modeling, an increase in the concentration of strontium in the form of SrOH+ and a decrease in the form of Sr2+ is observed in groundwater. At the same time, the dominance of strontium concentrations in the form of SrOH+ over Sr2+ does not occur. The reason for the sharp increase in the volume activities of 90Sr in strongly alkaline groundwater was the increase in the ISS > 5 mmol/l. An increase in the ISS of strongly alkaline groundwater leads to a decrease in the sorption properties of soils, and to the remobilization of adsorbed 90Sr back to groundwater through cation exchange. Probably, in the pH range of 9.5–12.4 and the ISS > 5 mmol/l, there is a change in the surface charge of soil particles, usually from negative to positive, in which cations cannot be sorbed, but, on the contrary, must to remobilize from the soil surface to groundwater. At the same time, pH = 9.5 is probably the point of zero charge (pzc). To assess the possibility of a relationship between the
concentrations of 90Sr and ISS, a correlation analysis using the geochemical statistics method was carried out. At the same time, the correlation coefficient K = 0.87, which proves the existence of a close relationship.
Keywords: Chornobyl nuclear power plant site, underground water, highly alkaline environment, ionic strength of the solution, thermodynamic modeling, migration of various 90Sr forms.
1. Singh B. K., Jain A., Kumar S., Tomar B. S., Tomar R., Manchanda V. K., Ramanathan S. (2009). Role of magnetite and humic acid in radionuclide migration in the environment. Journal of Contaminant Hydrology, vol. 106 (3–4), pp. 144–149. doi.org/10.1016/j.jconhyd.2009.02.004.
2. Kovalenko І. О., Panasiuk М. I., Skorbun А. D., Sosonna N. V., Ojovan M. I., Shevchenko O. L., Оnyshchenko І. P. (2021). Correlation between chemical composition and 90Sr concentrations in groundwater of the Chornobyl NPP industrial site. Journal of Environmental Radioactivity, vol. 240, 106756. doi.org/10.1016/j.jenvrad.2021.106756.
3. Lytvyn I. A., Panasyuk, M. I. Levin G. V., Onyschenko I. P. (2016). [Groundwater contamination by 90Sr on the territory of the Shelter object of the Chornobyl nuclear power plant]. Problems of Nuclear Power Plants Safety and of Chornobyl, vol. 26, 122–127. Available at: http://www.ispnpp.kiev.ua/wp-content/uploads/2017/2016_26/c122.pdf. (in Rus.)
4. Panasyuk M. I., Alferov A. M., Skorbun A. D. (2011). Radioactive contamination of groundwater and soils of the local zone of the “Shelter” object and the ChNPP industrial site. Collection of Reports “Twenty-Five Years of the Chernobyl Disaster. Security of the Future”, pp. 79–84.
5. Panasyuk M. I., Lytvyn I. A. (2017). Laws of distribution of uranium in groundwater of ChNPP industrial site. Nuclear Physics and Atomic Energy, vol. 18, pp. 56–62.
6. Panasyuk M. I., Lytvyn I. A., Liushnya E. P., Alfyoroff A. M., Levin G. V., Shestopalov V. M. (2015). Soils and ground water’s radioactive contamination into the local zone of the “Shelter” object and industrial site of Chernobyl NPP. In: Uranium — Past and Future Challenges. Cham: Springer International Publishing, pp. 657–664. doi.org/10.1007/978–3–319–11059–2_75
7. Panasyuk M. I., Matrosov D. T., Stoianov O. I., Levin G. V. (2018). Possibility of using thermodynamic modeling of formation of high concentrations of 90Sr in highly alkaline underground waters. Problems of Nuclear Power Plants Safety and of Chornobyl, pp. 120–126. doi. org/10.31717/1813–3584.18.31.14. (in Ukr.)
8. Wallace S. H., Shaw S., Morris K., Small J. S., Fuller A. J., Burke I. T. (2012). Effect of groundwater pH and ionic strength on strontium sorption in aquifer sediments: Implications for 90Sr mobility at contaminated nuclear sites. Applied Geochemistry, vol. 27, no. 8, pp. 1482–1491. doi.org/10.1016/j.apgeochem.2012.04.007.
9. Khan V. E., Odintsov A. A., Kalynovsky O. K., Dubenko P. N., Pazukshin E. M., Krasnov V. A. (2006). [Study of particularites of radionuclides composition in ground waters 4-g borehole of local area of the Shelter object]. Problems of Nuclear Power Plants Safety and of Chornobyl, no. 4, pp. 111–120. Available at: http://dspace.nbuv.gov.ua/handle/123456789/127887. (in Rus.)
10. Odintsov A. A., Khan V. E., Krasnov V. A., Pazukshin E. M. (2007). [Radionuclides in the groundwater of observation wells in the local zone of the Shelter object]. Radiochemistry, no. 5, pp. 467–473. Available at: http://chernobyldatabase.com/radionuclides-in-groundwaters-from-observation-holes-in-the-shelter-local-areaprobably-english. (in Rus.)
11. Bethke C. M., Farrel B., Sharifi M. (2022). GWB Essentials Guide. Illinois: Aqueous Solutions, LLC Champaign, 220 p. Available at: https://www.gwb.com/pdf/GWB2022/ GWBessentials.pdf
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