Penn State University (State College, Pennsylvania) senior student Collin Smyth won first place in the College of Earth and Mineral Sciences’ annual poster exhibition contest. His project, “Single-Pass Flow-Through Corrosion of Calcium Aluminosilicate Glass Powder,” illustrated recent research on the types of glass best suited for the long-term storage of nuclear waste.
Specifically, Smyth examined the composition dependence of glass corrosion, with applications in nuclear waste glass after vitrification. Smyth spent last summer conducting the research with Carlo Pantano, a professor of materials science and engineering at the school.
Smyth researched three components found in glass: calcium oxide (CaO), alumina, and silica. Nuclear waste glass can have about two dozen components, but his research focused on gaining empirical data on those three. In his research, Smyth passed water over powder-sized pieces of glass for 18 days. He found that higher silicon content led to a more stable glass that does not dissolve or corrode as easily. Dissolution is an issue, he explains, because that could release radioactive waste to the environment.
“When testing the 50% silica glass, the dissolution rate was about three times as high as the higher-percent silica samples, and the 40% silica was about four times as high,” Smyth says. “So, higher silica content will mean more corrosive-resistant storage for nuclear waste.”
“Glass corrosion has a lot of applications,” he adds. “People need to know about glass corrosion for thin films, biomaterials, and nuclear waste, so nuclear waste is kind of the main motivation here. But the results can be applied to other situations. The knowledge gained—because this is empirical data—can be used to determine the compositional effects of all glass corrosion.”
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