PNNL

Abstract

Vitrification and geologic disposal of radioactive material is planned in several countries, but there are remaining uncertainties related to the long-term stability of glass exposed to groundwater. Specifically, the crystallization of aluminosilicate zeolite minerals can accelerate the rate at which glass corrodes and radioactive material is released into the biosphere. In this study, we identify elemental species that may accelerate or suppress zeolite formation using a protocol to examine their effects on zeolite synthesis over a three-day duration. Our results are consistent with previous work demonstrating glass corrosion acceleration in the presence of calcium. Furthermore, we identify two elements – tin and lithium – as inhibitors of zeolite P2 nucleation and, thus, promising species for promoting the long-term durability of glass waste forms.