DOME is a first-of-its-kind facility that will enable the rapid development, testing and demonstration of privately developed advanced nuclear reactors.
April 8, 2026
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Construction of the National Reactor Innovation Center’s (NRIC) Demonstration of Microreactor Experiments (DOME) test bed is now complete.
Located at Idaho National Laboratory (INL), the first-of-its-kind facility will enable the rapid development, testing and demonstration of privately developed advanced nuclear reactors.
A bellwether for the nuclear energy renaissance, DOME is ready to host its first fueled microreactor test campaign.
Reactor Developers Find a Place to Call DOME
DOME’s completion comes at a pivotal time for the United States as first-movers in industry seek to accelerate the development and demonstration of advanced nuclear technologies that can help ensure the nation’s energy security and economic prosperity.
DOME is an actual dome,100 feet tall and 80 feet in diameter. The space provides a safe environment to test experimental reactor concepts and gather performance data that can be used to inform future commercial licensing applications.
Built from the repurposed Experimental Breeder Reactor-II containment structure, the facility helps reactor developers accelerate testing timelines, ultimately saving money and reducing project risk.
What makes DOME unique is that it is the only test bed in the world specifically designed to host fueled microreactor experiments that generate up to 20 megawatts of thermal energy.
Microreactors are compact nuclear reactors typically capable of producing up to 20 megawatts of thermal energy that could be used directly as heat or converted to electric power. Designed to be factory-built and portable, they are the right size to power independent microgrids, restore power in emergency situations, or supply remote communities that currently rely on diesel generators.
Due to their small size and ability to provide reliable power, microreactors are also being explored for use in space and maritime applications, as well as supporting military installations and the expanding energy needs of data centers.
"The DOME testbed will be a cornerstone of the Department of Energy’s comprehensive strategy to re-establish U.S. leadership in advanced nuclear technologies," said Dr. Rian Bahran, Deputy Assistant Secretary for Nuclear Reactors.
“DOME represents the kind of bold and creative infrastructure investment that America's nuclear resurgence demands,” said INL Director John Wagner. “We are accelerating the next generation of nuclear innovators from concept to demonstration at a pace the industry has not seen in decades.”
"NRIC built this test bed to answer the need of industry to have a facility that would enable them to swiftly convert their innovative concepts into practical demonstrations," said NRIC Director Brad Tomer. "With the information gathered from their testing at DOME, reactor developers will turn pioneering ideas into validated technologies to advance nuclear energy. We are extremely proud to offer this capability and cannot wait to see the impact it has on the nuclear industry.”
What’s Next?
DOME will now open its doors to reactor developers, starting with Radiant. The company has started their scheduled year-long test campaign of the Kaleidos Demonstration Unit. Staging will begin later this spring with initial startup of the reactor anticipated in the summer.
DOME experiments are scheduled through an annual competitive application process. The sequencing of experiments is based on several criteria, including technology readiness, fuel availability, regulatory approval plan and the ability of applicants to self-fund their testing campaigns. The next request for applications will open this spring.
Visit the DOME webpage to learn more.