THE KINETICS OF THE HYDRIDING OF URANIUM METAL II

The corrosion reaction of H-2 with massive uranium metal to form UH3 is described in terms of the initiation, pitting of the uranium surface at a linear rate, a transition to a higher linear rate, and finally a higher rate associated with the disintegration of the specimen. Infrared spectroscopic experiments monitor the chemistry of the uranium oxide film during heating to activate the uranium for hydriding. Low-magnification optical microscopy monitored the areal coverage of the uranium surface by UH3 during the pitting stage. High pressure measurements of the main linear rate process are reported and these results, pooled with earlier data, are described by a model that calculates valid rates over the range of 10 mPa to 1 MPa in H-2 pressure over a -20-degrees-C to 400-degrees-C temperature range.