METHOD OF STABILISING HIGHLY SALINE HIGH-ACTIVITY WASTES Russian patent published in 2010 - IPC G21F9/16 

FIELD: chemistry.

SUBSTANCE: invention relates to protection of the environment from radioactive contamination and can be used in the technology of processing, decontaminating liquid highly saline radioactive wastes (LRW), including high-activity wastes (HAW), for their subsequent prolonged storage and/or disposal. The method of stabilising liquid highly saline high-activity wastes is characterised by that it involves regulation of pH of the wastes to pH 8-9 values by adding orthophosphoric acid, successive addition of ion-exchange resin AB-17 in CT form, ions of divalent nickel and potassium ferrocyanide, the latter in amount of 0.2-0.4 and 0.3-0.6 wt % respectively, and sodium sulphide. The obtained mixture is hardened by adding binding substances - potassium dihydrophosphate and magnesium oxide in stoichiometric ratio in terms of amount of water of the hardened mixture with excess magnesium oxide - 5-10 wt %, obtaining a magnesium-potassium-phosphate matrix based on MgKPO₄·6H₂O, which is an analogue of natural phosphate minerals - monazite and apatite.

EFFECT: immobilisation of components of real liquid highly saline high-activity wastes of radiochemical plants, low energy consumption, easier realisation, possibility of hardening wastes in a wide pH range, high degree of accumulation of obtained matrices of components of high-activity wastes, high chemical resistance of the obtained matrices to leaching of radionuclides and other components in different temperature conditions and leaching agents.

4 cl, 2 ex, 2 dwg