METHOD OF PURIFYING EXTRACT OF ACTINIDES OF FIRST EXTRACTION CYCLE OF PUREX-PROCESS FROM TECHNETIUM Russian patent published in 2019 - IPC G21F9/06 

FIELD: physics.

SUBSTANCE: invention relates to the technology of reprocessing spent nuclear fuel of nuclear power plants. Method of purifying the actinide extract of the first extraction cycle of the PUREX process from technetium involves extraction of uranium, plutonium, neptunium with diluted tri-n-butylphosphate and purification of the obtained extract from the main amount of technetium. Extraction is performed in multistage extraction unit. Into the stage of supply of multistage extraction unit or point directly adjacent to power supply stage solution is supplied containing nitric acid with concentration from 3 to 5 mol/l and hydrogen peroxide, solution similar in composition is fed into the middle of the washing zone of the same extraction unit. Volume ratio of extractant flow to each of said solutions ranges from 7 to 15. Total amount of hydrogen peroxide provides molar ratio in water phase of head unit extraction zone .

EFFECT: invention enables to prevent extraction of zirconium and technetium, production of technetium with uranium, plutonium, neptunium extract for subsequent processing operations ranges from 10 % to 50 % of the amount of technetium supplied with the fuel solution.

1 cl, 4 dwg, 3 tbl, 3 ex