The effect of aluminum additions on the oxidation resistance of U3Si2

The effect of aluminum additions to U 3 Si 2 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 UO 2 and U metal oxidized in the same manner. Thermogravimetric data acquired in this study indicates that increasing amounts of Al in U 3 Si 2 further delays the onset of breakaway oxidation, providing enhanced oxidation resistance in air. Al 2 O 3 formation on U 3 Al 2 Si 3 is observed following a heat treatment performed at 500° C in air, demonstrating the potential of Al additions to improve the oxidation resistance of U 3 Si 2 .