METHOD OF PROCESSING IRRADIATED NUCLEAR FUEL Russian patent published in 2016 - IPC G21F9/00 

FIELD: physics; nuclear physics.

SUBSTANCE: invention relates to methods for the reprocessing of irradiated nuclear fuel (SNF) of VVER-1000 reactors to contain tritium, which is an active beta-emitting nuclides in the head reprocessing operations and can be used in nuclear power in the reprocessing of nuclear reactors. Process is a two step oxidation treatment of spent nuclear fuel (SNF oxidation) of uranium dioxide and includes a first stage heat treatment at a temperature of SNF fragments 400÷650°C in the air, additionally containing carbon dioxide, for 60-360 minutes, after which the second stage provides for - treatment at 350÷450°C in air or enriched oxygen environments, further containing water vapor in an amount corresponding to a dew point at 30-40°C. Wherein both steps are carried out at a constant or periodic mechanical activation of the reaction mass and the content of carbon dioxide in the gas mixture of the first stage is 4÷10 vol.%, the processing time spent fuel in the second stage is 60-360 m outputted from the reaction chamber the gas flow is cooled, the condensate is separated and fed to the cement compound and the non-condensable gas stream fed to the gas cleaning system.

EFFECT: technical result is to reduce the carryover of cesium 10 times, as well as reducing the amount of tritium SRW for more than 8 times during the oxidation treatment in the same degree of oxidation.

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