Authors : I. O. Kovalenko, M. I. Panasiuk, N. V. Sosonna, M. G. Buzynnyi, I. P. Onyshchenko
DOI : 10.3997/2214-4609.2023520103
Volume : 1
Issue : 1
Year : 2023
Page No : 1-5
The conditions of 90Sr migration with strongly alkaline groundwater at the Chornobyl NPP industrial site are analyzed. In well 1-2A, in a strongly alkaline environment, volumetric activities increase by 5–100 times to 25–500 Bq/l. The observations were carried out as part of the radiohydroecological monitoring in the area of the New Safe Confinement - Shelter Object (NSC-SO). The relationship between the concentrations of the main Ca2+, Na+ and K+ ions and the formation of high volumetric 90Sr activities in the observation well 1-2A was determined by the method of geochemical statistics. According to the thermodynamic modeling data, complex 90Sr compounds formed in a strongly alkaline environment SrOH+ and SrCO30 were determined, the mobility of which with groundwater is much higher than that of 90Sr2+ cation. It has been determined that the increase in ionic strength of solution (ISS) of groundwater from 2.5 to 8.12 mmol/L coincides with the beginning of the increase in groundwater pH from 7 to 11 and is ≈ 5 years ahead of the front of the spread of high 90Sr concentrations.