Identifikasi Fasa Pelet Bahan Bakar U-ZrHx Hasil Proses Sinter Dengan Atmosfer Nitrogen

PHASES IDENTIFICATION OF U-ZrHX FUEL PELLET SINTERED UNDER NITROGEN ATMOSPHERE. Phases identification of U-ZrHX fuel pellets sintered under nitrogen atmosphere has been carried out. This sintering process is intended to obtain higher density pellets that meet the requirements for use as a fuel in preasured water reactor (PWR). The results of this study are expected to be used for the determination of phase and density changes occured in U-ZrHx pellets at various Zr concentrations after sintering at various temperatures. PWR fuel from U-ZrHx pellet needs to be sintered to increase its density. At first, pellets made from U-ZrHx powder with Zr composition of 35, 45 and 55 wt.% through a pressing process at a pressure of 509-637 MPa. The resulted U-ZrHx green pellets were subsequently sintered under nitrogen gas atmosphere at 1200 °C and 1300 °C for a fixed sintering time of one hour. Phase analysis of the sintered U-ZrHx pellets was done by X-ray diffraction (XRD) technique and the data obtained were processed by using HighScore Plus software. The test results with XRD indicate the formation of phases such as U(ZrHr2), UO3, UO2, and Zr. The UO2 and Zr phases were characterized for their density, lattice parameter and percentage of weight. In this experiment it is desired to obtain U-ZrHx with high density without the formation of many phases. Density measurement shows that the density of zirconium metal and UO2 decreases with increasing sintering temperature (from 1200 °C to 1300 °C), while the lattice parameter increases with increasing sintering temperature. Data calculation of weight percentage for sintering at 1300 °C shows that the percentage values of the resulted zirconium metal and uranium dioxide are the closest to their theoritical calculation results.