Clays of the Republic of Belarus as engineering barriers for disposal of radioactive waste

Тhe criteria for compliance with which the properties and characteristics of clays from industrially exploited deposits of the Republic of Belarus were assessed in order to determine the possibility of their further use as part of the underlying screen of the radioactive waste disposal facility (RWDF) of the Belarusian NPP are defined. The performed experimental analysis of clay samples from 12 deposits of the Republic of Belarus showed that clays from the “Gorodnoye” deposits of the Brest region and the “Markovskoye” deposits of the Gomel region have optimal quality indicators for use as part of the RWDF engineering barrier (underlying screen). It has been established that these clay samples have high sorption properties for 137Cs and 85Sr radionuclides. The values of the degree of sorption of 137Cs and 85Sr radionuclides from an aqueous solution for the above clay samples are about 99 %, and the values of the quantitative indicator of sorption the coefficient of distribution of radionuclides – are about 104 l/kg. Over time, the fixation of 137Cs on the studied clay samples increases; as part of the underlying RWDF screen, these clays will be an effective anti-migration barrier to prevent the migration of radionuclides into the environment in the event of depressurization of radioactive waste packages.