By Tom Lotshaw
Associate Professor Channa De Silva (left), Brandon Sanders and Caleigh Gress Byrd work together in a lab in the new Apodaca Science Building.
Western Carolina University associate professor Channa De Silva and recent graduate Brandon Sanders explored how chemistry can help recycle America’s spent nuclear fuel.
This is an important question. Nuclear power provides about one-fifth of the electricity the United States consumes each year and more than half of its low-carbon energy. And one of the main challenges of expanding nuclear power generation as part of measures to reduce greenhouse gas emissions is radioactive waste – a material that raises significant environmental concerns. long-term storage and environment.
De Silva and Sanders’ research is helping scientists at the US Department of Energy develop methods to extract and recycle radioactive elements from spent nuclear fuel, a term for fuel after it has been used in a nuclear reactor.
Instead of storing these materials indefinitely, which is done at nuclear reactor sites across the country, the radioactive elements could be extracted and reused for more electricity generation, biomedical applications or other uses such as Scientific Research. This could help reduce the flow of nuclear waste and long-term storage needs as well as the need to extract new fuels.
“Our research is focused on finding methods to help recycle nuclear waste,” De Silva said.
De Silva and Sanders submitted their research proposal to the Department of Energy. He funded their work through a visiting professor program and associated them with the Seaborg Institute at Los Alamos National Laboratory in New Mexico.
The two were due to spend 15 weeks at Los Alamos last summer, using its powerful computers to run simulations exploring how differently arranged phosphorus molecules could be used to selectively bind to different radioactive elements in nuclear fuel. used – a key step to then extract them for recycling.
The pandemic, however, prevented De Silva and Sanders from traveling to New Mexico for the project.
Fortunately, WCU was able to accommodate the search. De Silva had previously licensed advanced simulation software with a Dean’s Grant as part of a previous Department of Energy research project exploring the effectiveness of nitrogen molecules as an agent of extraction. And the new Apodaca Science Building at WCU included powerful computer workstations that could run intensive simulation software and interface with Los Alamos National Laboratory’s advanced network.
Working with radioactive materials is difficult. The simulation software allowed De Silva and Sanders to more quickly and safely determine which molecular arrangements hold the most promise, based on theories of chemistry and quantum mechanics for their atomic and subatomic interactions with the elements. radioactive materials and other components of spent nuclear fuel.
A rendering of an arrangement of phosphorus molecules that De Silva and Sanders tested through computer simulations for the US Department of Energy. They explored various phosphorus molecules as possible extractants to remove radioactive materials from spent nuclear fuels so that the materials could be recycled.
De Silva and Sanders discovered arrangements of phosphorus molecules that appear to have the potential to bind radioactive materials such as uranium, plutonium, and neptunium with a high degree of efficiency and selectivity. “It’s promising,” De Silva said. “We can fine-tune the radioactive elements we extract based on the structure of the phosphorus molecules.”
Scientists at Los Alamos National Laboratory continue their research as De Silva and Sanders prepare to publish their findings. Scientists in the lab will build the most promising phosphorus molecules identified by De Silva and Sanders for real-world testing with nuclear waste. They will then share their findings with De Silva, who will continue to work with WCU students to improve the efficiency of molecular arrangements, run more simulations, and report back to the lab on their effectiveness as extractants.
“It’s a continuous two-way process,” De Silva said of the research.
Sanders, an Asheville native, said the project was an incredible learning opportunity that helped him decide to pursue a doctorate in theoretical chemistry. He graduated from WCU last December with a double major in chemistry and biology and begins his graduate studies this fall at the University of Tennessee at Knoxville.
“This project not only taught me about computational chemistry, but also about nuclear waste management. The experience helped me decide where I wanted to pursue my education and opened many doors for me,” Sanders said.
WCU’s chemistry department will continue to work with the Department of Energy, De Silva said. It’s a relationship that helps the university develop an interdisciplinary nuclear chemistry and engineering program that provides students with advanced research and workforce opportunities.
Earlier this year, the United States Nuclear Regulatory Commission announced that it would award a grant to WCU’s College of Engineering and Technology. Due to be awarded soon, the grant will be available for two years, providing scholarships of up to $5,000 per semester for juniors and seniors studying electrical power, mechanical and electrical disciplines. Students must agree to work in a nuclear-related job for six months after graduation for each year they receive the award. This initiative is led by Associate Professor of Engineering Bora Karayaka. Co-principal investigators include De Silva, assistant professor of engineering Andy Ritenour, and Chip Ferguson, professor of engineering and acting dean of the College of Engineering and Technology.
