nuclear milestone
Rendering of MARVEL Microreactor
Rendering of MARVEL Microreactor
Idaho National Laboratory

The U.S. Department of Energy’s (DOE) MARVEL microreactor achieved 90 percent 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.

MARVEL Moves Ahead

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 program recently wrapped up 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 percent threshold allows for minor changes that might arise due to unforeseen complexities during construction and assembly. 

While the design won’t be considered 100 percent final until the microreactor is cleared for operation, this 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.”

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The proposed MARVEL microreactor project at Idaho National Laboratory will help researchers understand how advanced reactors could play a part in intelligent energy grids.
Idaho National Laboratory

On the Horizon

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 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 to what is used in university research reactors across the country.

Additional milestones beyond that include safety analysis, training, and drafting procedures, followed by the construction and assembly of the microreactor, and finally, fuel loading.

Once operational, MARVEL will provide the nuclear industry with a dedicated location to quickly test, develop, and demonstrate microreactor technologies that are needed to help the United States reach its goal of achieving net-zero emissions by 2050.