THE KINETICS OF THE HYDRIDING OF URANIUM METAL II

The corrosion reaction of H-2 with massive uranium metal to form UH3 i s 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. Infra red spectroscopic experiments monitor the chemistry of the uranium oxi de film during heating to activate the uranium for hydriding. Low-magn ification optical microscopy monitored the areal coverage of the urani um surface by UH3 during the pitting stage. High pressure measurements of the main linear rate process are reported and these results, poole d with earlier data, are described by a model that calculates valid ra tes over the range of 10 mPa to 1 MPa in H-2 pressure over a -20-degre es-C to 400-degrees-C temperature range.