Concept art of the MARVEL microreactor (Image: INL)
The Department of Energy announced February 7 that fuel for the MARVEL microreactor, which Idaho National Laboratory plans to host inside the Transient Reactor Test (TREAT) facility, is now being fabricated by TRIGA International, with the first fuel delivery expected in spring 2025. MARVEL operation was expected “by the end of 2024” as recently as May 2023, but that timeline had shifted by October, when the DOE said MARVEL “is expected to be completed in early 2025.” Now, according to the DOE’s latest announcement, “Fuel loading for MARVEL is anticipated to occur in 2026, with the microreactor expected to be on line by 2027.”
Design for purpose: While the schedule has shifted, the aims of the project have not changed. The sodium-potassium–cooled microreactor is designed to generate 85 kilowatts of thermal energy. As envisioned, the project will be used to help industry partners demonstrate microreactor applications, evaluate systems for remote monitoring, and develop autonomous control technologies for new reactors. The system will operate for about two years, according to an INL factsheet.
The DOE announced in October 2023 that MARVEL had achieved 90 percent final design, which “further solidifies the design that may be fabricated.” With that milestone achieved, contracts—including a contract for fuel—could be signed.
Fuel from France: TRIGA International is a joint venture between Framatome and General Atomics and is the only fuel supplier for TRIGA research reactors around the world. The company was awarded a contract valued at about $8.4 million in November to produce 37 fuel elements for MARVEL. TRIGA International started the fabrication process in late January at its facility in Romans, France, according to the DOE.
The fuel in the works for MARVEL is similar to the TRIGA fuel used in university reactors for research and hands-on training. It was selected for its high safety performance and certified use in the United States, according to the DOE.
"Securing the fuel for the MARVEL microreactor project addresses a primary technical challenge,” said John Jackson, the national technical director for the DOE's microreactor program. “The initiation of fuel fabrication represents another tangible step toward making this exciting test platform a reality."
Next steps: The DOE microreactor program plans to submit MARVEL’s preliminary safety analysis report for review in summer 2024 as part of the DOE authorization process. In the meantime, testing of a full-scale, nonelectric prototype of the reactor is ongoing at the Pennsylvania facility of Creative Engineers Inc., to gather data on the system’s coolant flow and ensure the reactor will perform as expected.
