Abstract:

Surface corrosion of uranium metal during storage for 10 years in an inert gas atmosphere was examined. The factors causing uranium metal surface oxidation, spontaneous combustion, and etch pit formation were investigated using X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). The results show that the main factors are the iron concentration in the uranium, the long-term and sealed storage conditions, and chemical behaviors of intermediates in the storage environment. UO₂ and U₃O₈ cause etch pits, and the hydrogenation reaction product UH₃ combusts spontaneously on exposure to air.

Key words: Uranium, Impurity, Corrosion pit, UH₃