The Idaho National Laboratory has conducted the first safety test on high-burnup fast reactor fuel in over two decades. The test, performed at INL’s Transient Reactor Test facility, is part of a collaboration between the U.S. Department of Energy and the Japan Atomic Energy Agency to advance fast reactor fuel development.
According to DOE, the effort involved transient tests on high-burnup metallic fuel previously irradiated at INL’s Experimental Breeder Reactor-II. Researchers used a newly designed test capsule to monitor the fuel’s behavior during the experiment, yielding crucial data to support the development and qualification of future fast reactor fuels.
“The main ambition of this initiative is to test fast reactor fuels in their weakest state to better understand their limits and inform the development of improved designs,” said Colby Jensen, INL technical lead for transient testing. He added that the test data is valuable for advanced fuel designers because there have not been significant advances in fast reactor fuel designs in the U.S. since the EBR-II program ended in the late ’80s.
Following the tests, researchers will examine the specimens in detail at INL’s Hot Fuel Examination Facility and Irradiated Materials Characterization Laboratory. The initial experiments will conclude later this year, and further testing is planned over the next few years.
This joint initiative builds on another recent U.S.-Japan partnership on nuclear nonproliferation. In November 2024, DOE’s National Nuclear Security Administration partnered with Kyoto University to convert the university’s critical assembly reactor core from highly enriched uranium to high-assay low-enriched uranium fuel. This conversion reduces the proliferation risk associated with HEU, which can be used in nuclear weapons, while still allowing the facility to conduct advanced research.