METHOD FOR PROCESSING ABSORBER ROD COMPRISING CONTAMINATED BORON CARBIDE AND SODIUM Russian patent published in 2018 - IPC G21F9/28 

FIELD: recycling and waste management; nucleonics.

SUBSTANCE: invention relates to nuclear waste treatment. Method for processing an absorber rod comprising a shell, in which there is a material based on sintered boron carbide, the porosity of which is less than 1 % of the material volume, herewith the material has cracks that contain sodium and at least one radioactive substance, wherein the method includes the stage of processing, during which sodium is converted into sodium carbonate by the carbonation reaction as the result of bringing the material into contact with a reaction mixture for a treatment comprising, in molar percentages, 0.5–5 % of steam, 5–25 % of carbon dioxide and 74.5–94.5 % of a chemically inert gas, in such a way that an increase in the volume of carbonate causes the cracks and the shell opening, which starts at least from one slit made in the shell, as well as a propagation of the effects of the said treatment method within the material.

EFFECT: invention makes it possible to overcome as far as possible the difficulties associated with physicochemical properties of the material based on sintered boron carbide.

10 cl