The initial oxidation behavior of uranium and uranium-titanium alloys in standing storage

The oxidation kinetics of uranium and uranium-titanium (U-Ti) alloys at two typical storage atmospheres (dry air and 50 % RH air) were investigated based on the reflectance spectroscopy. Accurate kinetics parameters in parabolic stage were obtained by means of the accelerative experiments and simulated storage. The prediction models of uranium oxidation were established and the prediction result matched well with the test result in a 4-year storage experiment. The oxide breakaway phenomena caused by the compression stress in oxide were observed generally at 150-300 nm thickness. The oxide breakaway will lead to the accelerated oxidation deviating from the parabolic model.