Framatome’s accident tolerant fuel assembly completed four years of operation at Constellation Energy’s Calvert Cliffs Nuclear Power Plant in Maryland.
November 12, 2025
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Framatome’s first complete accident tolerant fuel assembly recently completed four years of operation at Constellation Energy’s Calvert Cliffs nuclear power plant in Maryland.
The lead fuel assembly is the first of its kind to operate in a commercial reactor and was developed through the U.S. Department of Energy’s (DOE) Accident Tolerant Fuel program.
The fuel assembly will complete its third cycle of operation in 2027.
Now Testing
The lead fuel assembly was first loaded into the Calvert Cliffs Unit 2 reactor in 2021 before it was examined and reinserted for an additional two years of operation in 2023.
The assembly contains 176 chromium-coated fuel rods and chromia-enhanced fuel pellets that can better respond to changes in the reactor core and are expected to reduce corrosion and hydrogen production under high-temperature conditions.
The fuel prototype builds on previous testing in the United States and Switzerland through Framatome’s PROtect program and could deliver the industry’s first major upgrade to nuclear fuel and cladding technologies since the 1970s.
“The performance of our technology continues to demonstrate the expertise of our people to develop safe, cost-effective solutions for our customers and our industry,” said Lionel Gaiffe, senior executive vice president, Fuel Business Unit at Framatome. “The Constellation team has been instrumental in helping us reach this milestone, leading the industry integrating accident tolerant fuel characteristics into their operations.”
"This public-private partnership is helping to drive the fulfillment of national power demands and executive orders issued by President Trump,” said Frank Goldner, the federal program manager for the Accident Tolerant Fuel Program. “This fuel assembly will continue operating under commercial conditions, providing crucial data to support the nation's energy objectives.”
Framatome and Constellation will reinsert the fuel during the spring 2025 refueling outage and will monitor its performance over the next two years.
The assembly will then be shipped to a DOE national laboratory for post-irradiation examination to help inform licensing activities.
Framatome, GE Vernova, and Westinghouse are all testing fuel concepts in commercial reactors across the country with the goal of widespread adoption by 2030.
The new fuel and cladding mixtures could help improve the overall economics and performance of today’s reactors and support President Trump’s recent executive orders to facilitate five gigawatts of power rates at existing power plants by 2030.
Learn more about accident tolerant fuels.