Scott Ball / Rivard Report
Inside a see-through glove box, University of Texas at San Antonio assistant professor Elizabeth Sooby Wood held a capsule with little grains of silvery metallic material.
The material, a compound of uranium and silicon, could potentially be a safer nuclear fuel than the compound of uranium and oxygen currently used in nuclear power plants all over the United States, Wood said.
That could help nuclear plants avoid the kind of catastrophic chain of events that caused Japan’s Fukushima nuclear disaster in 2011.
“We want to know when something breaks,” Wood said. “Really, the only way we have to test fuel until the point where it breaks is in small-scale testing in labs like mine.”
At UTSA, Wood runs one of the handful of labs in the U.S. where researchers can do this kind of materials testing. Now, under two contracts with Westinghouse Electric Co. totaling around $450,000, Wood is hoping to further test the uranium-silicon fuel with additives that could help it withstand a breach in the protective cladding that surrounds a nuclear fuel rod that would would expose the fuel to steam and water.
Across the U.S., 60 nuclear plants in 30 states provided nearly 20 percent of the electrical power that Americans received in 2018. That includes the South Texas Project, a nuclear plant partially owned by CPS Energy, which provided about 14 percent of San Antonio’s power last year.
This energy is generated with none of the carbon emissions that contribute to global warming. But nuclear has its own challenges, including the risk of emergencies that could allow a release of radioactive material into the environment, as happened with Fukushima following a tsunami that disabled the plant’s cooling mechanisms.
“The dangers need to be respected, like any big industrial application,” Wood said. “But I think it’s a great, viable option.”
Known to nuclear scientists since the 1950s, the type of fuel Wood works with, uranium silicide, early on showed “a lot of favorable qualities and a few question marks,” she said. It lost ground to a different compound, uranium dioxide, which Wood said is almost universally the fuel of choice for commercial reactors.
But Wood says uranium silicide has some intriguing potential because of its resistance to the intense conditions present inside of a nuclear reactor.
Nuclear plants create electricity by using the heat generated by nuclear fission reactions inside radioactive fuel rods to generate steam. The steam then turns a turbine, which generates an electrical charge.
To test the extremes that uranium silicide can handle, Wood and her students put tiny pieces of it into a small steam furnace. Inside, it can face temperatures of more than 2,200 degrees Fahrenheit with an atmosphere of 100 percent steam. After that, they’ll pull it out and see if it survived.
“Some of it, you just open up the furnace and say, ‘Yeah, this is broken,’” Wood said.
But sometimes, the fuel fails in ways too subtle to see with the naked eye. That’s when she and her students will use X-ray diffraction, scanning electron microscopes, and other tools to get an up-close look at what went wrong.
On a tour of her lab, Wood pointed out an electron microscope image of a crack in a piece of fuel. At that scale, it looked like an aerial photo of an immense canyon cutting across a flat plateau.
Wood isn’t alone in doing this type of work in San Antonio. The Westinghouse grant also supports research at Southwest Research Institute to complement Wood’s work.
Kent Coulter, a Southwest Research Institute senior program manager collaborating with Wood on the research, was traveling Thursday and did not immediately respond to a phone message from the Rivard Report seeking comment.
Wood, who was at Los Alamos National Laboratory before coming to UTSA about a year and a half ago, said she’s excited that the electric power industry is funding research like hers.
“I’m pretty pumped about industry getting into this because this type of research has been going on since the beginning, but there’s not been a lot of funding for it because you don’t have an industry backer,” Wood said. “In the nuclear industry, we’ve had this nuclear reactor design that’s worked and worked liked a champ for 40 years, 50 years, and it hasn’t changed a whole lot.”