Glass-ceramic composites: The next generation nuclear waste form material?
Andrew Grosvenor
Professor, Department of Chemistry
University of Saskatchewan
Monday, November 6, 2023
1:30 p.m.
In-person: C2-361 (Reading Room)
Abstract: Multiple solid-state materials have been proposed/developed for the sequestration of high-level nuclear waste such as spent/used nuclear fuel. Glass-based waste forms are used (or proposed for use) by many countries owing to the ease of synthesis and the significant number of different waste elements that can be incorporated into a glass matrix. However, these waste forms have a lower resistance to corrosion compared crystalline ceramic oxides and a lower capacity to incorporate high concentrations of heavy waste elements (e.g., actinides). Crystalline ceramic oxides and phosphates have been proposed for the sequestration of heavy waste elements, but the structures adopted by these materials are unable to accommodate all waste elements found in spent nuclear fuel. We have been investigating glass-ceramic composite materials where crystallites of ceramic oxides or phosphates are dispersed in a glass matrix. The hypothesis is that these composite materials will enable larger concentrations of all waste elements to be incorporated in the waste form with the lighter/smaller ions being preferentially incorporated in the glass matrix while the heavier/larger ions are incorporated into specific crystallographic positions in the ceramic oxides/phosphates. Our investigations of composite materials containing different oxide/phosphate crystallites dispersed in a borosilicate glass matrix will be discussed during this presentation with an emphasis placed on the effect that synthesis conditions and composition has on the ability to form these materials, as well as the corrosion resistance and tolerance to radiation induced damage of these materials.