Abstract: The present disclosure relates to a pellet containing an oxide additive to improve a nuclear-fission-gas-adsorption ability of a uranium-dioxide pellet used as nuclear fuel and increase the grain size thereof, and to a method of manufacturing the same. A La2O3—Al2O3—SiO2 sintering additive is added to uranium dioxide so that mass movement is accelerated due to the liquid phase generated during sintering of the uranium-dioxide pellet, which promotes the growth of grains thereof. Further, since less volatilization occurs during sintering due to the low vapor pressure of the liquid phase, efficient additive performance is exhibited, so the liquid phase surrounding the grain boundary effectively adsorbs cesium, which is a nuclear fission gas.

Abstract: Proposed are nuclear fuel pellets showing high oxidation resistance in a steam atmosphere and a method for manufacturing same. The method includes: preparing a powder mixture by mixing a sintering additive powder including Cr2O3, MnO, and SiO2 with a uranium dioxide powder; forming a molded body by subjecting the powder mixture to compression molding; and sintering the molded body in a weak oxidative atmosphere in which an oxygen potential is ?581.9 kJ/mol to ?218.2 kJ/mol. The nuclear fuel pellets contain 0.05% to 0.16% by weight of the sintering additive composed of Cr2O3, MnO, and SiO2. A liquid phase generated during the sintering accelerates grain growth and inhibits reaction between uranium dioxide with steam by forming a film at the grain boundary of the uranium dioxide. This reduces leakage of a fission material by improving high-temperature water vapor oxidation resistance at around 1204° C. in a loss-of-coolant accident condition.

Abstract: The present disclosure relates to a pellet containing an oxide additive to improve a nuclear-fission-gas-adsorption ability of a uranium-dioxide pellet used as nuclear fuel and increase the grain size thereof, and to a method of manufacturing the same. A La2O3—Al2O3—SiO2 sintering additive is added to uranium dioxide so that mass movement is accelerated due to the liquid phase generated during sintering of the uranium-dioxide pellet, which promotes the growth of grains thereof. Further, since less volatilization occurs during sintering due to the low vapor pressure of the liquid phase, efficient additive performance is exhibited, so the liquid phase surrounding the grain boundary effectively adsorbs cesium, which is a nuclear fission gas.