METHOD OF PREPARING SPENT CARBIDE NUCLEAR FUEL FOR EXTRACTION PROCESSING (VERSIONS) Russian patent published in 2014 - IPC G21F9/00 

FIELD: chemistry.

SUBSTANCE: method includes neutralising complexing ligands contained in nitrate solution of carbide fuel via oxidation thereof with nitric acid in the presence of a catalyst in the form of a polyvalent metal which is located in the nitrate solution or is added before or after dissolving spent carbide nuclear fuel, said metal being selected from: cerium, iron, manganese, technetium, mercury. Further, the method includes heating the nitrate solution of the carbide fuel or performing oxidation directly in the process of dissolving the carbide fuel in nitric acid in the presence of a catalyst with subsequent dissolution in the oxidised solution of the carbide fuel of the oxide or metallic spent nuclear fuel, or performing simultaneous oxidation of complexing ligands and dissolving the oxide or metallic spent nuclear fuel in the solution of the carbide fuel. An alternative solution includes performing similar preparation of the spent carbide nuclear fuel for extraction processing, followed by mixing the oxidised solution of the carbide fuel with solutions of oxide or metallic spent nuclear fuel or direct addition of the required amount of a zirconium nitrate solution or a solution of another polyvalent metal-complexing agent.

EFFECT: avoiding the need to use powerful oxidising agent.

13 cl, 12 ex