METHOD OF DISSOLVING PLUTONIUM DIOXIDE, MOX-FUEL SCRAP AND EXTRACTING AMERICIUM Russian patent published in 2020 - IPC G21C19/46 G21C3/42 C01G56/00 C22B60/02 

FIELD: nuclear equipment.

SUBSTANCE: invention relates to nuclear engineering, particularly to processes of dissolving plutonium dioxide (PD) during refining thereof for use in producing uranium-plutonium fuel (particularly MOX fuel), dissolving scrap of MOX-fuel (powders and tablets of uranium-plutonium fuel) and separation of americium at their carrying out. When dissolving plutonium dioxide and scrap MOX-fuel cerium is used as an oxidising agent, and for its regeneration in addition to electrochemical method ozone is used. When dissolving scrap MOX-fuel, first dissolving uranium in scrap at temperature 50–80 °C with simultaneous supply of ozone under the solution mirror and with cerium concentration of up to 0.05 M/l, and then at temperature of 30–50 °C is dissolving plutonium also with ozone feed or together with electrochemical oxidant generation. In oxalate deposition, the cerium which is present in the raffinate is used as a coprecipitate of americium. At insufficient concentration of americium in a mixture of americium and cerium oxides mixture is returned to operation of dissolution of PD, and at sufficient concentration of americium – for temporary storage.

EFFECT: invention enables to use cerium as an oxidising agent and coprecipitating americium when dissolving PD and oxalate deposition, respectively.

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