Rate control sintering of the uranium dioxide

The application of rate controlled sintering (RCS) technique for fabricating oxide fuel pellets in industrial conditions is investigated. Green pellets of UO₂ (with no additives) which underwent industrial-type compacting were sintered in reducing Ar - 8% H₂ medium using dynamic and isothermal RCS modes with exposure at 1600 °C during 8 hours. Decreasing shrinkage rate resulted in growth of sintered density for the dynamic RCS mode. Opposite to the results of earlier works [1,2], decreasing heating rate did not result in reducing sintering rate. Isothermal mode allowed sintering rate to be maintained between 0.1- 0.15%/min. Temperature-time modes obtained using RCS are close to the operation mode of through-type furnace used for mass production. (paper)