The effect of aluminum additions on the oxidation resistance of U3Si2

The effect of aluminum additions to U3Si2 is investigated as a means to improve the oxidation resistance of this nuclear fuel form. Four U-Si-Al compositions have been synthesized and characterized using scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. The onsets of breakaway oxidation are identified in air thermal ramp tests using thermogravimetric analysis. The final oxidation products following 1000° C air exposure are identified using x-ray diffraction and compared to those of UO2 and U metal oxidized in the same manner. Thermogravimetric data acquired in this study indicates that increasing amounts of Al in U3Si2 further delays the onset of breakaway oxidation, providing enhanced oxidation resistance in air. Al2O3 formation on U3Al2Si3 is observed following a heat treatment performed at 500° C in air, demonstrating the potential of Al additions to improve the oxidation resistance of U3Si2.