A new method for UF6 conversion to UO2 with excellent characteristics

Several wet and dry methods for the conversion of UF6 to UO2 powder, e.g., the ammonium diuranate (ADU) process and the integrated dry route process, have been developed to an industrial scale. Although the UO2 powders fabricated by conventional methods have good ceramic characteristics, there is room for improvement. To extend burnup of nuclear fuel, a decrease in fission gas release from UO2 pellets is required. It has been considered that large-grain pellets satisfy this requirement, but it is difficult to obtain such large-grain pellets by using conventional UO2 powder. A new method has been developed to produce a highly active UO2 powder that can greatly contribute to improvement of the fabrication process of nuclear fuel pellet. By using this highly active UO2 powder, large-grain pellets can be made easily, and low-temperature sintering can be achieved