Abstract：Using U3Si2 powder as raw material, U3Si2 fuel pellets were prepared by vacuum sintering method. The effect of sintering temperature on the density of U3Si2 pellets was studied. The uranium concentration and impurity content of U3Si2 fuel pellets were also revealed. The microstructure and thermal conductivity property of U3Si2 fuel pellets were then characterized. The results show that the density of U3Si2 fuel pellets first increases and then decreases with the increase of sintering temperature. The U3Si2 fuel pellets sintered at 1 550 ℃ for 2 h possesses the highest relative density, which is about 96.7%. And the uranium mass concentration of the pellets is 10.81 g/cm3, significantly higher than the uranium mass concentration of the active UO2 pellets. The U3Si2 fuel pellet is composed of U3Si2, USi and UO2 phases. The thermal diffusivity of the pellet increases gradually with the increase of temperature. The thermal diffusivity at 500 ℃ is 3.95 mm2/s, which is about two times higher than that of the UO2 pellet.
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2022, Vol. 27 
