HIGH BURN-UP NUCLEAR FUEL TABLET AND METHOD OF MAKING SAID TABLET (VERSIONS) Russian patent published in 2009 - IPC G21C3/62 

FIELD: nuclear physics.

SUBSTANCE: invention relates to nuclear power engineering and can be used for making a nuclear fuel tablet based on uranium dioxide. The high burn-up nuclear fuel tablet based on uranium dioxide contains silicon and aluminium oxides, uniformly distributed in the entire volume of the tablet, where with respect to uranium, aluminium content ranges from 0.005 to 0.03 wt %, and silicon - from 0.003 to 0.02 wt %, mass ratio of aluminium to silicon ranges from 1.5 to 4, size of particles of uranium dioxide ranges from 20 to 45 mcm. The tablet can also contain gadolinium oxide, which is in form of a solid solution with uranium dioxide and is uniformly distributed in the entire volume of the tablet, where content of gadolinium oxide with respect to uranium ranges from 0.3 to 10.0 wt %, or contains erbium oxide, which is in form of a solid solution with uranium dioxide and is uniformly distributed in the entire volume of the tablet, where content of erbium oxide with respect to uranium ranges from 0.3 to 0.8 wt %. In accordance with the method of making such a tablet of nuclear fuel, uranium dioxide powder and powder of silicon and aluminium oxides are prepared. The aluminium oxide powder is pre-calcined in air at temperature ranging from 700°C to 800°C. The aluminiun and silicon oxide powder is ground to particle size less than 40 mcm. A "liquid" plasticiser is prepared in form of an aqueous solution, for example, polyvinyl alcohol and glycerin or "dry" plasticiser, for example zinc stearate. The aluminium and silicon oxide (AI₂O₃ and SiO₃) powder is added to the plasticiser and a mixture is formed. Uranium dioxide powder is mixed with the obtained mixture. Moulding powder is prepared, tablets are moulded, sintered at high temperature and then polished.

EFFECT: increased burn-up fraction of fuel while using up to 70-100 MW·day/kg U.

15 cl 1 tbl, 2 dwg