METHOD FOR PROCESSING OF SPENT NUCLEAR FUEL OF NUCLEAR POWER PLANTS Russian patent published in 2012 - IPC G21F9/08 

FIELD: power industry.

SUBSTANCE: invention refers to processing technology of spent nuclear fuel of nuclear power plants (NPP SNF). Processing method of NPP SNF involves extraction of U, Pu, Np, Tc and Zr with diluted tributyl phosphate, removal of Mo to raffinate and re-extraction of Zr to a separate solution of weak nitric acid with washing off actinides by means of extractant. Extraction is performed at the number of stages of not more than 8 from solution containing 350-900 g/l of U and 1.5-3.5 mol/l of HNO₃, at saturation of extract with uranium to 75-90% of the tank and content in raffinate of 0.3-1.2 mol/l of HNO₃, with introduction to U extraction zone of solution of complexing agent of molybdenum; after that, the removed flows of raffinate and Zr re-extract are separately evaporated with total regeneration of nitric acid. Vat solutions are supplied for curing of high-activity technological wastes (HTW).

EFFECT: invention allows preventing the formation of deposits of zirconium molybdate and barium nitrate during extraction operations and improving ecological indices of the production.

4 cl, 2 dwg, 2 ex, 1 tbl