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Low‐Temperature Sintering Bi–Si–Zn‐Oxide Glasses for Use in Either Glass Composite Materials or Core/Shell 129 I Waste Forms
Author(s) -
Garino Terry J.,
Nenoff Tina M.,
Krumhansl James L.,
Rademacher David X.
Publication year - 2011
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2011.04542.x
Subject(s) - materials science , sintering , composite number , amorphous solid , chemical engineering , oxide , shell (structure) , thermal expansion , metallurgy , composite material , chemistry , engineering , organic chemistry
Spent nuclear fuel contains 129 I, 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 129 I 2 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 I 2 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.