METHOD FOR RECOVERING LIQUID RADIOACTIVE WASTES Russian patent published in 2000 - IPC

FIELD: recovery of intermediate-level-activity wastes at nuclear power plants and radiochemical facilities. SUBSTANCE: method includes natural-zeolite sorption of radionuclides and case-hardening of radioactive natural zeolites using binding system of granular blast-furnace slag and clay component mixed up with sodium silicate solution so as to immobilize spent sorbent to obtain mechanically strong and water-resistant geocement with water-resistant cement compounds dispensing with high-energy technology of recovering sorbents having high-level radioactivity; dry components of binding system are used in following proportion, mass percent: natural zeolite - maximum 40; granular blast-furnace slag - 51-85; clay component - 3-13; amount of sodium silicate solution depends on desired molar ratio of sodium oxide in sodium silicate to aluminum oxide in granular blast-furnace slag and in clay component (1 to 1.5); silicate modulus of sodium silicate solution being used is 1.5, its density is 1.3-1.4 g/cu.cm ; sorption is conducted under transient conditions; pH of liquid radioactive wastes is adjusted between 8 and 12. EFFECT: reduced volume and cost of recovered wastes, improved safety of process. 4 cl, 5 ex