Dissolution behavior of MgO-P.sub.2O.sub.5 glass system for vitrification of high-level radioactive waste

The MgO-P.sub.2O.sub.5 glass system exhibits atypical behavior in the relationship between physical properties around the metaphosphate composition (MgO/P.sub.2O.sub.5 = 1) when used as a glass matrix during the vitrification of radioactive waste. The dissolution of phosphate glasses is usually dominated by hydration reactions. However, the solidified glass waste exhibits higher water resistance than the parent glass matrix because of the presence of strong P-O-M bonds (M being the waste element) within the cross-linked elemental structure of the glass waste, indicating that the dissolution of the solidified glass waste form is controlled primarily by the hydrolysis reaction.