Correlation and Predicfion of Explosive Metal-Water Reaction Temperatures

The fast, potentially hazardous chemical reaction between a metal and water can occur in a nuclear reactor only above the melting point of the metal, T_m. There is a critical temperature θ > T_m, at which the process changes over from the slow corrosion-like reaction to one which proceeds with explosive speed and violence. For the alkali metals, θ is only slightly greater than T_m. The critical temperature θ has been experimentally determined for three high melting point metals, Al, Zr, and U; and it is shown that θ is approximately equal to the temperature at which the metal vapor pressure is 0.15 mm for these cases. This relation suggests that the initiation of the violent metal-water reaction for refractory metals may be a vapor phase phenomenon. On the basis of this hypothesis, and the empirical correlations developed, predictions of the value of θ are presented for a number of other metals for which experimental data are not presently available.