There’s a 12-foot-deep pit in the floor of the Transient Reactor Test (TREAT) Facility at Idaho National Laboratory. Already home to a test reactor that puts up to 20 gigawatts of power into nuclear fuel in a short pulse to test its safety, the TREAT building is awaiting another nuclear reactor that will occupy the pit. MARVEL (short for Microreactor Applications Research Validation and Evaluation) is a distinctive test platform that will aid a rapidly growing nuclear industry as the world searches for dependable low-carbon energy sources. MARVEL will help advanced nuclear developers in several key ways:
- Provide experience with design, start-up, operation and eventual decommissioning of a new reactor, one of the first built at INL in five decades;
- Development and demonstration of key technologies for microreactor development;
- Testing of key operation functions of a microreactor; and
- Enabling nuclear developers to test microreactor applications and access data to refine their designs on the path to commercialization.
Technology has advanced in the 50 years since a new reactor last went critical at INL, and there’s a huge amount of new knowledge and flexible capabilities to incorporate into a new generation of nuclear power systems.
One of the most intriguing objectives in the nuclear energy industry is the deployment of microreactors, small nuclear power plants that can be factory-fabricated and transported to their intended operation location, can potentially be operated remotely with minimal on-site staffing, and incorporate advanced safety features.
Building the Future of Nuclear
The MARVEL project kicked off in 2020, and after four years of planning, design, and supporting experiments, the fabrication of its components began in spring of 2024, with stakeholders across the nation eagerly watching its progress.
“We envision microreactors initially providing carbon-free power to support energy-intensive industrial processes, military bases and remote communities where the current cost of energy is high for the consumer,” said John Jackson, national technical director of the Microreactor Program for the U.S. Department of Energy Office of Nuclear Energy. “Different reactors are suited to specific use cases, in the same way people look for a particular type of motor vehicle based on their need. We see microreactors as an important part of tomorrow’s energy mix.
Finding the Right Partners
One expected advantage of microreactors is the ability to fabricate them in factories. This will require working with industry partners who have the capabilities to build components to the U.S. nuclear industry’s exacting standards. INL selected Carolina Fabricators, Inc. (CFI) to construct the first large component—the guard vessel that will surround the MARVEL core.
“As the industry ramps up to potentially build hundreds of new reactors, fabrication is a critical part of the supply chain,” said MARVEL project manager Mark Nefzger. “The ability to make steel components to a Nuclear Quality Assurance standard is going to be highly sought after, and we’ve appreciated the work CFI has done.”
“Our team has risen to the challenge issued by the MARVEL team to meet the exacting specifications of the project” said CFI Sales Manager Patrick Halligan. “We are extremely grateful for our relationship with INL and the opportunity to serve as a partner on MARVEL. We certainly look forward to many other exciting opportunities the advanced nuclear industry will bring.”
Following qualification tests of the guard vessel throughout the spring and early summer, INL will take steps to begin fabrication work on other MARVEL components, including the coolant system and the support structure for the reactor. The fuel for the reactor is also in production by TRIGA International, a joint venture between Framatome and General Atomics, with delivery anticipated in the spring of 2025. The commissioning of MARVEL is targeted for 2027.
