Researchers at Idaho National Laboratory (INL) recently made commercial-grade high-assay low-enriched uranium (HALEU) fuel pellets

Researchers at Idaho National Laboratory (INL), in collaboration with General Electric and supported by the US Department of Energy (DOE), have made significant advancements in the development of high-assay low-enriched uranium (HALEU) fuel pellets for next-generation nuclear reactors.

Jennifer K. Watkins, Ph.D., U.S. WIN member, explains her role in this accomplishment.

Jennifer K. Watkins, Ph.D.

Summarize your career up to your current role

I spent 16 years in a finance position for a municipality and decided I wanted to do something else. I went back to school to finish my bachelor’s degree and was introduced to materials science. During my undergraduate career, I started working as a research assistant in the Advanced Materials Laboratory at Boise State University. It was during that time that I discovered the benefits of what nuclear energy has to offer and began my work in advanced nuclear fuel technology. My advisor offered me a graduate position and I opted to continue my education pursuing a doctorate in Materials Science & Engineering. I was fortunate to receive a Department of Energy Nuclear Energy University Program graduate fellowship, which allowed me to intern for 6 months at INL. During that time, I assisted with fabrication of U3Si2 fuel pellets, which were the first non-oxide fuel pellets to be irradiated in a commercial nuclear reactor. That experience led me to the INL Graduate Fellow program. That program allowed me to finish my coursework at Boise State, after which I transitioned to INL full-time to complete my Ph.D. research, focusing mainly on uranium nitride projects. After defending my dissertation, I took a full-time staff position at INL continuing my work in fabrication and synthesis of advanced technology nuclear fuels.

Why did you decide to work in this area (HALEU)?

This particular project was a collaboration with industry to show that HALEU pellets could be fabricated to commercial standards utilizing the available feedstock at INL. HALEU fuel will be essential for use in advanced reactors which are slated to be demonstrated within the next decade.

What were the main challenges you faced during the development of the HALEU fuel pellets?

Ensuring we had met all the commercial standards required by our collaborator.

What do you see for the future of research at INL?

Expanding in all aspects of nuclear research. New reactor materials and technologies are essential to getting these advanced technologies matured to the point of commercial deployment. Research led by INL in collaboration with industry partners will support these demonstrations and their development.

How did U.S. WIN help you during your career?

Being able to connect with other women in the nuclear industry and finding connections through networking at the U.S. WIN conference and committees has been valuable. Knowing I’ve got support and resources to draw on when I encounter challenging situations is so beneficial, not only in career advancement, but in personal well-being.

How are you promoting U.S. WIN with your colleagues?

I routinely recruit for U.S. WIN; the committees ALWAYS need assistance. I am always talking up the organization through my role on the Communications Committee’s Twitter team and as part of our outreach for Nuclear Science Week.

More about HALEU

Development of HALEU Fuel: HALEU, uranium enriched to between 5% and 20% uranium-235, is essential for advanced nuclear reactors. INL has produced fuel pellets enriched to 15% uranium-235, marking a crucial step in the testing and qualification process.

Advantages of HALEU: HALEU fuel allows for increased in-core lifetimes, higher enrichment, and more uranium-235 atoms per pellet, leading to longer cycle times, less waste, and less downtime for refueling.

Fabrication Techniques: The HALEU fuel pellets were made using a traditional powder metallurgy process, similar to that used for light water reactor fuel, demonstrating the capability to fabricate commercial quality uranium dioxide (UO2) HALEU.

Collaboration with General Electric: INL is collaborating with General Electric to fabricate 100-150 pellets for irradiation in the Advanced Test Reactor, testing the endurance of a prototype cladding material that could improve reactor performance.

DOE’s Role and Funding: The project is funded under the DOE’s Accident Tolerant Fuel Program, which aims to commercialize new fuels within the decade, enhancing plant performance and safety response to severe accidents.

Broader Implications: Demonstrating UO2 HALEU fabrication opens the door for other types of HALEU fuels, such as nitride, boride, carbide, and silicide, which have higher uranium densities and could offer even higher performance levels for advanced reactors.

Commercial Standards: Initial characterization efforts suggest that the high-density pellets produced at INL meet all commercial standards for uranium dioxide, providing options for industry and government agencies to make fuel samples with a wider range of enrichment.

Future Prospects: INL is positioned as the premier place in the US for developing unique and novel fuel concepts, with a wide range of feedstock options and a flexible DOE-based enrichment license allowing adaptability to user needs.