The U.S. Accident Tolerant Fuels Program: Recent Accomplishments and Transition to Deployment

Following 2012 U.S. Congress direction, the Department of Energy's (DOE) Office of Nuclear Energy gave priority to developing enhanced nuclear fuels and cladding technology for light water reactors (LWRs) that would improve safety under severe accident conditions. DOE developed a research program that would be capstoned by Lead Test Assembly (LTA) insertion into a commercial power plant by the end of 2022. The initiative quickly attracted broad stakeholder engagement leading to deployment of LTAs, supplied by all three US fuel vendors, in several commercial plants by 2019. Accomplishing DOE's stated goal three years ahead of the original ambitious target. The early success of the ATF technology development program was largely credited to a strong collaboration between DOE's national laboratories and commercial nuclear fuel vendors as well as the focused engagement of several utilities and the U.S. Nuclear Regulatory Commission. This holistic perspective made it clear that wide-spread implementation of ATF technology would be accelerated if both safety and economic incentives were simultaneously realized. An expanded mission for the program codified in 2019 Public Law 115-439, “Nuclear Energy Innovation and Modernization Act” (NEIMA), and as re-established by the 2024 Public Law 118-67. Most recently, the program has expanded research activities beyond ATF technology development and demonstration, with emphasis on coated cladding and doped fuel pellet technology. The program mission now includes extending burnup from the current U.S. regulatory limit of 62 GWD/MTU up to 75 GWD/MTU or beyond, significantly enhancing the economic attractiveness of the ATF concepts. This extension would be accompanied by an increase in enrichment needed to support utilization of this fuel. This effort will demonstrate modern methodologies that will pave the way for further uprates enabled by ATF technology. This paper reviews the status of the ATF concepts focusing on recent accomplishments, especially those made by the DOE national laboratories in support of the industrial concepts.