The nation’s growing energy needs have prompted U.S. policymakers to take another look at nuclear power, and researchers like Christopher Cahill
are working to provide those policymakers with solutions for the storage and disposal of nuclear fuel.
“Nuclear energy is no longer the dirty word it was even 10 years ago,” said Cahill, a Fulbright scholar and a Columbian College chemistry professor since 2000. “When you compare it to other technologies, it’s cleaner, better.”
Cahill’s research has focused on storage of uranium after it has been used in a reactor. Uranium, explained Cahill, “behaves” when it’s stored in a safe, dry place. But as soon as it gets wet, it oxidizes and becomes highly soluble, mobile and toxic, which could pose problems if it seeped from a storage site. Researchers are seeking ways to make that form of uranium insoluble.
Cahill and his team of graduate students and researchers from the Pacific Northwest National Lab have found that soluble uranium, when combined with iron-rich minerals, will change into an immobile form. In addition, his team is creating synthetic compounds containing the immobile uranium, which has not been widely found in nature. But, noted Cahill, if it can be created in the lab, there’s a chance that it could be occurring naturally more often and change to the mobile form. Such findings have the potential to impact future groundwater studies as well as reactor and storage design. $1.2 Million Grant To Expand Scope of Study
Cahill recently received a five-year, $1.2 million grant from the Department of Energy’s Frontier Research Center to expand his work in nuclear fuel storage. He plans to explore what would happen, for example, if soluble uranium moves into an area containing dissolved organic material, such as a pond or bog. Research will involve heating uranium salts mixed with organic compounds. The resulting solids can then be analyzed using X-rays to generate three-dimensional, atomic-level images of their structures.
The research may show that the uranium remains mobile. Or, perhaps one of the mixtures will crystallize, making the uranium insoluble. “That would be a great find,” Cahill noted, speculating that such a substance could be placed around a storage facility.
Nuclear energy has its place in what should be a “balanced portfolio” of potential sources, according to Cahill. “I’m genuinely concerned about the nuclear fuel cycle in this country and on this planet. We haven’t built a reactor in the U.S. in 30 years. We’ve had this huge gap in technology and research. It’s an opportunity for me to make a contribution.”