METHOD OF LIQUID RADIOACTIVE WASTES CONCENTRATION Russian patent published in 2020 - IPC G21F9/08 

FIELD: nuclear physics and equipment.

SUBSTANCE: invention relates to nuclear-chemical, particularly radiochemical, technologies at different stages of nuclear fuel cycle (NFC). Method of concentration of liquid radioactive wastes from extraction treatment of high-burnt nuclear fuel of NPP includes partial destruction of nitric acid during continuous evaporation when a solution containing a reducing agent is supplied to the vat pulper of circulating type. Reducing agent used is a mixture of formaldehyde and formic acid. Process is carried out at solution delay in the bottom part of the apparatus with supply of an aqueous solution of a mixture of formaldehyde and formic acid or a solution of formic acid as a reducing agent in 3–5 hours after the beginning of the process using a mixture of formaldehyde and formic acid.

EFFECT: invention makes it possible to reduce use of a fire-explosive reagent in a continuous process of evaporation of wastes.

6 cl, 12 ex, 1 dwg, 1 tbl