Reactor to be built at Idaho National Laboratory with plans to connect it to microgrid
Fuel for the Marvel microreactor, which Idaho National Laboratory plans to host at its transient reactor test (Treat) facility, is now being fabricated by Triga International, with the first fuel delivery expected in spring 2025, the US Department of Energy announced.
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 the plant “is expected to be completed in early 2025.”
Now, according to the DOE’s latest announcement, fuel loading for Marvel is anticipated in 2026, with the microreactor expected to be on line by 2027.
Triga International is a joint venture between French nuclear fuel cycle company Framatome and US energy and defence corporation General Atomics. It is the only fuel supplier for Triga research reactors around the world.
Triga is a nuclear reactor model designed by General Atomics that is used for research and hands-on training activities. Triga-type fuel designs are now being explored for new applications beyond university training. Framatome said Triga fuel can be used for non-Triga plants such as small modular, micro or advanced reactors.
The Marvel design is a sodium-potassium-cooled microreactor that will generate 85 kilowatts of thermal energy. It will be built inside the Treat facility with plans to connect it to a microgrid.
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% final design, which “further solidifies the design that may be fabricated.” With that milestone achieved, contracts – including a contract for fuel – could be signed.
Triga International was awarded a contract valued at about $8.4m (€7.8m) in November to produce 37 fuel elements for Marvel.
The company began the fabrication process in late January at its at dedicated Triga manufacturing facility at Romans-sur-Isère, near Grenoble in southeast France, according to the DOE.
The fuel for Marvel will be similar to the Triga fuel used in university reactors for research and hands-on training. The DOE said it was selected for its high safety performance and certified use in the US.
