METHOD FOR NUCLEAR PRODUCTION WASTE PROCESSING Russian patent published in 2018 - IPC G21F9/28 

FIELD: chemistry.

SUBSTANCE: method for nuclear production waste processing involves electrochemical dissolution of fuel rods in a nitric acid solution in an electrolyzer, while maintaining a constant concentration of nitric acid in the range 5.0÷6.0 M. The electrolyzer body is a cathode. The anode is made in the form of a clamp with a possibility of its periodic decompression and compression when the current deviates from the nominal value to 10%. At that, the ratio of the areas of the anode part surface immersed in the solution and the soluble fuel elements is (2÷7):1, and the ratio of current densities at the anode and soluble fuel elements is 1:(2÷7). After electrochemical dissolution, accompanied by shell removal and partial dissolution of uranium, clarified solutions are sent to uranium extraction, and undissolved residues are placed in a mixture of nitric and hydrofluoric acids with addition to aluminum solution at a molar ratio of HF:HNO components₃: Al=1:(4÷8):(0.2÷0.4). Clarified solutions are subjected to uranium extraction.

EFFECT: invention allows to increase the uranium recovery during the processing of fuel rods in a stainless-steel shell with a fuel core containing zirconium.

2 cl, 1 tbl