MANUFACTURING METHOD OF CERAMIC FUEL PELLETS FOR FUEL ELEMENTS OF NUCLEAR REACTOR Russian patent published in 2011 - IPC G21C3/02 

FIELD: power industry.

SUBSTANCE: pellets are pressed in two stages; at that, first, pressing of workpiece of internal core of pellet with axial hole is performed from moulding powder of highly-enriched uranium dioxide UO₂, which contains alloying additives, by using press mould of smaller diameter. Then, obtained workpiece is put into press mould of larger diameter; after that, the gap formed between workpiece and internal wall of press mould is filled with moulding powder from low-enriched uranium dioxide UO₂ for creation of outer layer of pellet and the second pressing stage is performed. It is proposed to obtain moulding powder of low-enriched uranium dioxide UO₂ by using water technology including preparation of uranyl nitrate solution, two-stage deposition of ammonium polyuranate with hydrogen nitride, calcination of deposit, and reduction of monoxide-oxide to uranium dioxide UO₂. Size of granules of low-enriched powder of UO₂ uranium dioxide shall be less than 100 mcm.

EFFECT: higher burnout degree of nuclear fuel.

4 cl, 3 dwg, 2 tbl, 2 ex