The US Department of Energy’s (DOE’s) MARVEL microreactor has achieved 90% final design, a key step that will allow the project to move forward with fabrication and construction. MARVEL will be the first new reactor at Idaho National Laboratory (INL) in more than four decades and is expected to be completed in early 2025.
The reactor will be used to help industry partners demonstrate microreactor applications, evaluate systems for remote monitoring, and develop autonomous control technologies for new reactors. The MARVEL design is a sodium-potassium-cooled microreactor that will generate 85 kilowatts of thermal energy. It will be built inside the Transient Reactor Test Facility at INL with future plans to connect it to a microgrid.
DOE’s microreactor programme recently completed MARVEL’s final design report, which included more than 200 supporting documents detailing the engineering analysis, specifications, requirements, and drawings of the reactor design. The 90% threshold allows for minor changes that might arise due to unforeseen complexities during construction and assembly. The design will not be considered 100% final until the microreactor is cleared for operation. However, the current stage permits INL to award contracts and proceed with next steps.
“This is truly a precedent-setting moment for DOE and the nation,” said John Jackson, the national technical director for DOE's microreactor program. “This milestone paves the way for a microreactor test platform that will answer fundamental questions of how microreactors will operate and the variety of services they can provide to lower emissions across multiple energy sectors.”
The MARVEL project can seek blanket DOE approval to fabricate the reactor components and systems. The project team is currently testing a full-scale, electrically heated replica of MARVEL that will help to verify the performance of the microreactor’s cooling system.
Later this year, INL will work to purchase fuel for the microreactor, which will use a version of TRIGA fuel that is similar that used in US university research reactors.
Future milestones include safety analysis, training, and drafting procedures, followed by the construction and assembly of the microreactor, and finally, fuel loading. MARVEL will provide the nuclear industry with a dedicated location to test, develop, and demonstrate microreactor technologies needed to help the US achieve net-zero emissions by 2050.
Image: Rendering of the MARVEL microreactor (courtesy of Idaho National Laboratory)
