Chemical durability of Savannah River Plant waste glass as a function of groundwater pH

The leachability of Savannah River Plant (SRP) waste glass was assessed for leachants in the pH range of 3 to 11. A parabolic relationship was observed between leachability and solution pH in this range. At 40/sup 0/C, leachability was lowest within a pH range of approximately 5 to 9. Most of the groundwaters in potential repository locations have pH values in this range. Below pH 5 and above pH 9, leachability of the waste glass increases. Leachability as a function of solution pH was studied first at room temperature and then in more detail at 40/sup 0/C, 90/sup 0/C, and 150/sup 0/C using abbreviated MCC-1 and MCC-2 static leaching tests. These data were then correlated with the formation and stabilization of surface layers that are produced on the waste glass during leaching.