The company - a subsidiary of X-energy LLC - said the agreement supports continued design and development for the X-energy XENITH microreactor under the Advanced Nuclear Power for Installations (ANPI) programme, an initiative led by the Defense Innovation Unit (DIU) in partnership with the Department of the Air Force.

The programme, launched last year, is designed to accelerate the deployment of next-generation microreactor technologies to provide resilient, secure power at military installations, and enables governmental sponsors like the Department of the Air Force to engage with X-energy under a flexible contracting mechanism that allows for faster development and deployment of commercial nuclear systems.

X-energy said the agreement aligns with President Donald Trumps Executive Order on Deploying Advanced Nuclear Reactor Technologies for National Security, issued in May this year, which directs the Department of Defense (DOD) to deploy an advanced reactor at a military installation before the end of the decade. As part of this effort, X-energy was selected to demonstrate commercial microreactors that can deliver resilient and secure energy to power critical defense infrastructure and remote microgrids.

X-energys XENITH is a 3-10 MWe high-temperature gas-cooled microreactor first developed for DODs Project Pele, a mobile microreactor initiative led by the Strategic Capabilities Office. The design was selected to continue into an enhanced engineering phase, focused on achieving preliminary design maturity and initiating pre-licensing engagement with the US Nuclear Regulatory Commission for both military and commercial applications.

"XENITH delivers reliable, clean power anywhere its needed, from remote communities to critical military installations, with the simplicity of factory-built deployment and the reliability of 20-year uninterrupted operation," according to X-energy. "Deployed in months, not years, XENITH provides energy independence where traditional power infrastructure falls short."

In addition to XENITH, X-energy is advancing the deployment of its Xe-100 high-temperature gas-cooled reactor as a grid-scale energy solution for utilities, industrial customers, and hyperscalers. The company is also constructing a first-in-the-nation advanced nuclear fuel fabrication facility to manufacture its proprietary TRISO-X fuel.

X-energy was among eight potential microreactor suppliers selected by DOD in April this year as eligible to seek funding as part of the ANPI programme.

Earlier this month, California-based Radiant - one of the other companies selected - said an agreement it has signed with the DIU and the Department of the Air Force was the first-ever deal designed to deliver a mass-manufactured nuclear microreactor to a US military base. The company is developing the 1 MWe Kaleidos high-temperature gas-cooled portable microreactor. Radiant says it plans to test its first reactor in 2026, with initial customer deployments beginning in 2028.