Idaho National Laboratory Opens DOME Test Bed to Accelerate Advanced Microreactor Development
Why It Matters
Idaho is positioning itself at the center of America’s nuclear energy revival, and the opening of a first-of-its-kind microreactor test bed at Idaho National Laboratory marks a significant step toward that goal. The facility is designed to compress the timeline for bringing next-generation nuclear reactors to market — a development that could drive jobs, investment, and energy security across Idaho and the broader Mountain West.
As the nation’s demand for reliable, affordable power grows — particularly to support expanding data centers and domestic manufacturing — advanced nuclear technology is increasingly seen as a critical piece of the energy independence puzzle. Idaho leaders have already raised concerns about whether the region’s workforce can keep pace with the surge in nuclear industry demand coming to the Intermountain West.
What Happened
Officials from Idaho National Laboratory and the U.S. Department of Energy gathered on April 8 at the Materials and Fuels Complex at INL in Idaho Falls to officially celebrate the grand opening of the DOME test bed — the National Reactor Innovation Center Demonstration of Microreactor Experiments facility.
DOME is a purpose-built test bed that enables private companies to develop, test, and demonstrate advanced nuclear reactor designs under real-world operating conditions. The facility was built from the repurposed Experimental Breeder Reactor-II dome, a former reactor structure at INL, giving the site both historical significance and modern engineering utility.
Construction was accelerated by nearly a year, officials said, in support of the Trump administration’s nuclear executive orders and the urgent national need for advanced nuclear energy deployment.
By the Numbers
- 80 feet in diameter and 100 feet tall — the physical dimensions of the repurposed DOME structure
- Up to 20 megawatts of thermal energy — the maximum output DOME is designed to host during microreactor experiments
- Nearly 1 year — the amount by which construction was accelerated to meet national energy priorities
- 1 year — the length of the inaugural testing program planned by Radiant’s Kaleidos Demonstration Unit, set to begin this spring
- Annual competitive application cycles — the process by which companies will schedule testing campaigns at the facility, funded by the applicants themselves
What They Said
Dr. Rian Bahran, Deputy Assistant Secretary for Nuclear Reactors at the Department of Energy, called DOME a cornerstone of efforts to re-establish U.S. leadership in advanced nuclear technologies. “By providing essential infrastructure for testing and validation of new reactor designs, DOME directly supports our programmatic goals, accelerating the development and deployment of innovative solutions vital for energy security and economic growth,” Bahran said.
INL Director John Wagner framed the facility as a generational leap forward. “We are accelerating the next generation of nuclear innovators from concept to demonstration at a pace the industry has not seen in decades,” Wagner said.
NRIC Director Brad Tomer emphasized the facility’s industry-facing purpose, noting that data collected through DOME testing will help reactor developers convert innovative concepts into validated, licensable technologies.
Zoom Out
DOME’s opening comes as the United States works to reclaim ground lost to foreign competitors — particularly China and Russia — in the global advanced nuclear market. The Trump administration has made domestic nuclear expansion a priority, issuing executive orders aimed at accelerating reactor deployment and reducing regulatory bottlenecks.
Idaho stands to benefit significantly from this national push. Governor Brad Little has actively pitched Idaho as the rightful leader of America’s nuclear future, though that vision has drawn scrutiny from critics who worry the state could be saddled with nuclear waste without proportional economic return. DOME’s opening strengthens Idaho’s claim as an indispensable hub for nuclear innovation rather than merely a storage site.
Nationally, the push for advanced microreactors is driven in part by soaring electricity demand from artificial intelligence infrastructure and domestic manufacturing reshoring — sectors that require consistent, carbon-free baseload power that traditional renewables struggle to provide reliably.
What’s Next
INL is preparing for DOME’s first nuclear-fueled experiment this year. Radiant’s Kaleidos Demonstration Unit is scheduled to begin a year-long testing program this spring, marking the facility’s inaugural experiment using actual nuclear fuel. Future experiments will be selected through an annual competitive application process, with priority given based on technology readiness, fuel availability, and regulatory approval plans. All applicants are required to fund their own testing campaigns.
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