*Member, The American Ceramic Society
Low-Temperature Sintering Bi–Si–Zn-Oxide Glasses for Use in Either Glass Composite Materials or Core/Shell 129I Waste Forms
Article first published online: 20 APR 2011
© 2011 The American Ceramic Society
Journal of the American Ceramic Society
Volume 94, Issue 8, pages 2412–2419, August 2011
How to Cite
Garino, T. J., Nenoff, T. M., Krumhansl, J. L. and Rademacher, D. X. (2011), Low-Temperature Sintering Bi–Si–Zn-Oxide Glasses for Use in Either Glass Composite Materials or Core/Shell 129I Waste Forms. Journal of the American Ceramic Society, 94: 2412–2419. doi: 10.1111/j.1551-2916.2011.04542.x
W.-C. Wei—contributing editor
- Issue published online: 9 AUG 2011
- Article first published online: 20 APR 2011
- Manuscript No. 28857. Received November 8, 2010; approved March 4, 2011.
Spent nuclear fuel contains 129I, which is of particular concern due to its very long half-life, its potential mobility in the environment, and its deleterious effect on human health. In spent fuel reprocessing schemes under consideration, a gas stream containing 129I2 would be passed through a bed of Ag-loaded zeolites such as Ag–mordenite (Ag–MOR). We have investigated the use of a low-temperature sintering bismuth–silicon–zinc-oxide glass powder mixed with either AgI or AgI–MOR to produce dense glass composite material waste forms that can be processed at 550°C, where AgI volatility is low. We have demonstrated that when fine silver flake is added to the mixture, any adsorbed I2 released during heating of AgI–MOR reacts with the silver to form AgI in situ. Furthermore, we have shown that mixtures of the glass with the AgI–MOR or AgI are durable in aqueous environments. Finally, we have developed a process to fabricate core/shell waste forms where the core of AgI–MOR or AgI and glass is encased in a shell of glass that protects the core from contact with the environment. To prevent cracking of the shell due to thermal expansion mismatch between the core and shell, amorphous silica was added to the shell to form a composite with a lower coefficient of thermal expansion.