David Hatchett, vice president for research and professor of radiochemistry at UNLV, talks during an interview Friday at the university.
Hatchett has developed a method to reclaim and reuse uranium hexafluoride, a nuclear waste byproduct of uranium enrichment.
Editor’s note: Este artículo está traducido al español en la página 8.
“
UNLV researchers are on the cutting edge of techniques that can reduce the amount of waste left over from the process of creating nuclear fuel and weapons by rendering those toxic waste products both safe and useful.
Enriching uranium for bombs and nuclear power generation since the Cold War of the mid-20th century has led to an abundance of depleted uranium hexafluoride, a potentially deadly substance that sits sealed in aboveground canisters around the world by the millions of pounds. The nuclear waste, according to UNLV radiochemistry professor David Hatchett and his colleagues, can be reclaimed and reused — such as feeding the power grid.
He doesn’t call it recycling, but “strategic material recovery.”
“We have these materials that we want to not have to mine, and we want to recover and reuse,” said Hatchett, who is also the university’s vice president of research. “Make it safe, and then if you can recover it, reuse it, without producing additional waste, then that’s a positive.”
The U.S. Department of Energy, aware of Hatchett and his team’s extensive prior experience in reclaiming lithium and rare earth metals, approached him a few years ago asking if they could use their internationally patented techniques to convert uranium hexafluoride, or UF6, into a safe, stable compound. Their progress is encouraging.
UF6 is used to enrich uranium metal to sustain the fission reactions — the explosive splitting of the heavy uranium atoms — that lead to both energy production and the destructive power of nuclear bombs. Uranium has been enriched this way around the world for more than 70 years.
The United States has more than half of the world’s UF6, and exposure can essentially burn and drown a person from the inside, Hatchett said.
In chemistry, volatility describes how readily a substance vaporizes. UF6 is highly volatile, and the canisters it is stored in can degrade and leak.
“We have these materials that we want to not have to mine, and we want to recover and reuse. Make it safe, and then if you can recover it, reuse it, without producing additional waste, then that’s a positive.”
David Hatchett, radiochemistry professor at UNLV
This compound, Hatchett said plainly, is “nasty.” The chemical reaction inside the human body can lead to searing burns and acidic fluid filling the lungs, and that acid can leach calcium out of bones.
“We have a lot of this depleted uranium material, and it’s not very nice material,” he said. “It’s volatile, so you would inhale it. It produces hydrofluoric acid in your lungs, because it reacts with the water in your system. And probably, the hydrofluoric acid would be worse for you than the uranium.”
That’s the bad news. The good news is, it doesn’t have to stay volatile.
The Hatchett group stabilizes the compound by dissolving it in an ionic liquid, or a liquid salt, he said. That permanently alters the compound’s chemistry, so even when removed from the liquid it is no longer the nasty UF6.
And once stabilized, it can be converted back to uranium metal and used for shielding the containers used to store and transport radioactive materials, or ammunition and ordnance, or fuel.
Hatchett points out how the fuel option is attractive when solar or hydroelectric energy need augmentation.
The sun isn’t always out to generate solar energy, and the hydroelectric Hoover Dam relies on the dwindling water of the Colorado River to produce electricity.
Reliable nuclear energy would allow Nevada to diversify its economy by drawing businesses and through the industrial-scale processing of the UF6 itself, he said.
The process has shown promise for scaling up. But before it can be used on an industrial level, more research and work are needed, Hatchett said.
UNLV has academic programs in radiochemistry — the study of the chemistry of radioactive materials, like uranium — along with health physics and nuclear engineering. Hatchett said the university probably wouldn’t have these uncommon opportunities without the historical perspective of the Nevada Test Site, where the federal government tested America’s nuclear weapons from the 1950s into the ’90s. This allows access to quality study materials like UF6, which the university obtains from Urenco, a government contractor that manages the nation’s radioactive waste.
“Our economic development team is the mechanism to connect university innovators with industry and entrepreneurs who can apply UNLV research in ways that will change lives for the better,” said Zach Miles, interim vice president for UNLV’s office of economic development, in a statement. “The work happening in laboratories throughout UNLV has the potential to solve some of the world’s most pressing challenges, and it’s gratifying to work with innovators like Professor Hatchett to bring new, bold ideas to life.”
There are 1.2 million metric tons of radioactive waste globally, Hatchett said. Of those, about 700,000 metric tons — or about 1.5 billion pounds — are in the U.S., he said.
None of the radiochemists on campus would say they’re in favor of a dump site, Hatchett said — they don’t want to see Yucca Mountain actually be used as a radioactive waste repository.
They want to investigate how to minimize nuclear waste, and Nevada scholars are uniquely equipped to do so.
“We are one of the few states who has a full understanding of what it is and how to work with it,” he said. hillary.davis@gmgvegas.com / 702-990-8949 / @HillaryLVSun