The US Department of Energy (DOE) has awarded a contract to TRIGA International, a joint venture between Framatome and General Atomics, to fabricate fuel for the MARVEL microreactor at Idaho National Laboratory(INL). The TRIGA fuel fabrication contract was awarded through Battelle Energy Alliance (BEA), which operates INL. Framatome will manufacture a fuel similar to the TRIGA fuel used in US university reactors.

Framatome’s dedicated TRIGA manufacturing facility at CERCA Romans was selected to fabricate this fuel in line with the schedule of the MARVEL project. Framatome relaunched its dedicated TRIGA manufacturing facility at CERCA in response to the DOE Office of Nuclear Energy’s goal to maintain world-class research and development capabilities. After a seven-year $80m modernisation project, operations resumed at the end of 2022 for the first time since 2012. Framatome CERCA is the world’s only manufacturer and supplier of uranium-zirconium hydride fuel for use in TRIGA type research reactors.

This award follows the restart of the TRIGA programme after nearly 10 years, and the first successful fabrication and delivery of TRIGA metallic fuel to Penn State University in September. “DOE and TRIGA International have reestablished the TRIGA fuel supply to support U.S. university research reactors,” said Assistant Secretary for Nuclear Energy Dr Kathryn Huff. “With this contract, we will leverage that investment to support demonstration of advanced reactors as well.”

MARVEL is a sodium-potassium-cooled microreactor that will generate roughly 85 kWt and serve as a test capability to speed the development of microreactor technology. MARVEL recently achieved 90% final design enabling the project to move forward with fabrication and construction. The 90% threshold allows for minor changes that might arise due to unforeseen complexities during construction and assembly. The project team is currently testing a full-scale, electrically heated replica of MARVEL that will help verify the performance of the microreactor’s cooling system.

While the design won’t be considered 100% final until the microreactor is cleared for operation, this stage permits INL to award contracts and proceed with next steps. It also permits DOE to award contracts for reactor components and fuel fabrication. Under the DOE Microreactor Program, it will be built inside the Transient Reactor Test Facility at INL with future plans to connect it to a microgrid. The reactor will be used to help industry partners demonstrate microreactor applications, evaluate systems for remote monitoring, and potentially demonstrate control technologies for new reactors.

Later this year, INL will work to purchase fuel for the microreactor, which will use a version of TRIGA fuel similar to that used in university research reactors across the US. Additional milestones beyond that include safety analysis, training, and drafting procedures, followed by the construction and assembly of the microreactor, and finally, fuel loading.

TRIGA is a reactor designed by General Atomics that is used for research and hands-on training. TRIGA type fuel designs are now being explored for new applications beyond university training. The unique properties of TRIGA fuel can be seamlessly transitioned to non-TRIGA plants such as small modular, micro or advanced reactors. Framatome and General Atomics created the TRIGA International SAS joint venture in 1995 to market TRIGA fuel elements manufactured at CERCA Romans. More than 66 TRIGA units have been built around the world and approximately 38 reactors are still in operation.


Image: A model of the MARVEL microreactor to be built inside the Transient Reactor Test Facility at INL (courtesy of INL)