Stony Brook Advanced Nuclear Waste Research Highlighted in U.S. Department of Energy Video

As the United States looks toward expanding advanced nuclear energy technologies, researchers at Stony Brook University are working on one of the field's biggest long-term challenges: what to do with the waste.

That work recently earned national attention for Stony Brook Professor Jason Trelewicz, whose research was featured in a video to highlight his work with the U.S. Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E). ARPA-E supports high-risk, high-reward energy innovations designed to strengthen U.S. energy security and accelerate transformative technologies that are still too early for large-scale private investment.

Trelewicz, aprofessor in the Department of Materials Science and Chemical Engineering in the College of Engineering and Applied Sciences, also holds a joint appointment with Oak Ridge National Laboratory in Tennessee and serves as principal investigator of Stony Brook's ARPA-E ONWARDS Program on "Matrix Engineered Tri-structural Isotropic Fuel Compacts Enabling Advanced Reactor Fuel Cycles (MATRICY)."

"The ARPA-E ONWARDS program was developed to reduce both the economic and environmental impact of nuclear waste from advanced reactor technologies," Trelewicz said.

ONWARDS, which stands for "Optimizing Nuclear Waste and Advanced Reactor Disposal Systems," challenged researchers to reduce nuclear waste footprints tenfold compared to conventional light water reactor fuel cycles.

Trelewicz said his team at Stony Brook developed what is known as the MATRICY technology, an "inert matrix fuel form" designed to improve fuel utilization and reduce the waste burden on the back end of the fuel cycle.

The result, he said, has exceeded the original goals of the program.

"We've now demonstrated a significant reduction in waste footprint beyond the 10x originally designed as part of the ONWARDS program," Trelewicz said.

While the science behind advanced nuclear fuels is highly technical, the broader goal is straightforward: to reduce the amount of long-lived nuclear waste generated by future reactors while improving efficiency and sustainability.

Trelewicz explained that the MATRICY team, led by Stony Brook University along with the University of Tennessee Knoxville and the Massachusetts Institute of Technology, combines reactor physics calculations with techno-economic analysis throughout the fuel development process, creating what he described as a "closed loop design process" to optimize fuel performance.

The research also focuses heavily on scalability, a critical factor for implementation. "The pressureless sintering technology we developed is inherently scalable," Trelewicz said, which provides a direct pathway for the production of cylindrical fuel compacts for prismatic reactor designs and spherical fuel pebbles for pebble-bed reactors. According to Trelewicz, both fuel geometries are now possible using the technology developed at Stony Brook.

Throughout the project, Trelewicz said researchers have worked closely with reactor designers to better understand industry priorities and practical deployment challenges.

"One of the primary things they've conveyed to us is that fission product retention is one of the most critical aspects to them," he said.

His team is continuing measurements and reactor physics calculations to demonstrate how the technology could benefit specific advanced reactor platforms.

- Beth Squire