Stored in steel drums and buried in mountainsides, nuclear waste can remain radioactive for hundreds of thousands of years. Reducing the space needed to store the waste saves time and money and will reduce the overall environmental impact, says Richard Brow, Curators’ Professor of ceramic engineering.
With funding from the U.S. Office of Nuclear Energy, Brow is working to find a way to make the waste vitrify — or, turn into glass — more efficiently. Using surrogates in place of radioactive isotopes, Brow melts borosilicate glass (similar to the material Pyrex glassware is made from) and surrogates, looking for the sweet spot where a process known as phase separation and crystallization can capture the most waste in the smallest volume of a chemically stable glass. Reducing the volume could help address the nuclear waste storage problem.
Brow uses techniques developed in part by researchers in the Peaslee Steel Manufacturing Research Center at S&T.
“To understand how fast these processes occur, we will quench the melts — probably from 1,450 degrees, Celsius — at different rates to freeze in different microstructures, ranging from phase-separated droplets, known as fast quench, to fully crystallized phases, or slow quench,” he says.
It’s all to get to the point where the borosilicate glass concentrates the radioactive components into micro-phases within the glass. And when that happens, the benefits will be substantial.
“We could possibly double our waste loading,” Brow says.