METHOD OF REAGENT DEACTIVATION OF SOILS FROM CESIUM RADIONUCLIDES Russian patent published in 2010 - IPC G21F9/28 

FIELD: power industry.

SUBSTANCE: reagent deactivation of soils from cesium radionuclides involves soil treatment with water solution containing deactivating reagents, and mineral acids which are used as the latter, with further separation of water solution with deactivating reagents from cleaned soil; after that there performed is removal of cesium radionuclides from separated water solution with deactivating reagents by supplying alkali metal or ammonium to the above ferrocyanide solution to concentration of 6·10^-4 ÷7·10^-2 M with formation of deposit containing cesium radionuclides which are supplied to be stored, and to water solution with residual content of deactivating reagents there added is sulphuric and phosphoric acids to working concentrations to be used during deactivation of further soil batch. Cleaned soil is separated into sand and fine fractions with water gravity separation; at that, fine fraction is supplied to the storehouse of nuclear waste, and sand fraction is subject to reactant treatment with 0.5-2 M sulphuric acid solution at temperature of 80-95°C in percolation installation till the value of relative activity of cesium radionuclides corresponding to sanitary regulations is obtained; after that cesium radionuclides extracted from sand fraction are supplied to nuclear waste storehouse, and sand fraction cleaned from cesium radionuclides is flushed with water solution to neutral reaction and returned to the extraction point.

EFFECT: increasing the coefficient value of soil deactivation from cesium radionuclides.