DOME test bed opens at Idaho lab to host privately built advanced reactors

by Clarence Oxford
Los Angeles CA (SPX) Apr 30, 2026
The National Reactor Innovation Center at Idaho National Laboratory has declared the Demonstration of Microreactor Experiments test bed, known as DOME, open for business, marking a milestone for the U.S. advanced nuclear sector.

DOME is described as the world's first test bed purpose-built to host and demonstrate microreactors developed by private companies, giving industry partners access to INL infrastructure and regulatory experience to validate reactor designs before commercial deployment.

The facility is designed to accept a range of microreactor concepts and allow developers to conduct full-power demonstrations in a controlled environment with existing nuclear material handling, safety systems, and regulatory framework already in place.

NRIC officials said DOME lowers barriers for private advanced reactor developers by removing the need for each company to build its own demonstration infrastructure, which can require years of licensing and hundreds of millions of dollars in capital outlay.

The opening positions INL as the primary U.S. venue for near-term microreactor demonstrations, with several private developers already identified as prospective users of the facility.

Microreactors are compact, factory-fabricated fission systems typically rated below 20 megawatts thermal, intended for applications including remote community power, industrial heat supply, military forward bases, and disaster recovery scenarios where grid connection is unavailable or unreliable.

DOME is capable of hosting reactors using a variety of fuel types and coolant systems, and is equipped with instrumentation and data acquisition infrastructure to support performance characterization, safety testing, and regulatory documentation requirements.

INL said the test bed complements other NRIC programs including design consultation, licensing support, and site permitting assistance that are available to advanced reactor developers across the public and private sectors.

The Department of Energy has identified microreactors and other advanced nuclear concepts as central to its clean energy strategy, citing their potential to deliver zero-carbon baseload or dispatchable power in settings where large conventional reactors and variable renewable sources are impractical.

DOME's inauguration follows years of planning and construction at INL's Materials and Fuels Complex, and comes as several U.S. and allied governments have signaled renewed interest in nuclear energy as a hedge against fossil fuel price volatility and grid reliability concerns.