US Army funds microreactors to keep critical base systems running

The US Army is becoming an early customer for microreactors—small nuclear reactors—to keep critical base operations running when the electricity grid fails. Project Janus announced $2.2 billion in awards in August 2026 and plans to fund 20 reactors at bases in the contiguous United States through the early 2030s.

The programme addresses a barrier for an emerging technology: the first units are too expensive to attract commercial buyers. As Fortune describes it, the Army is paying for early adoption in the hope that larger-scale production will lower costs and make the reactors more useful to the military.

The initial goal is not to supply entire bases. The reactors would provide permanent power, rather than serve only as backup generators, for operations that must continue through an outage. Jeff Waksman, the Army’s top energy official and Project Janus leader, said the focus is on those essential operations.

Analysis

Suppliers promise longer refuelling intervals with different installation needs

Long intervals between refuelling are a major part of the military appeal. Radiant president and chief operating officer Tori Shivanandan said diesel generators need fuel every one to two days. Fuel convoys follow repeatable routes, making them targets, she said. Radiant says its Kaleidos reactor would run for three years between refuellings, potentially reducing that exposure.

Suppliers are pursuing different balances between power output and ease of transport. Their proposed specifications are not proof of reliable field operation. A megawatt is a unit of power equal to one million watts.

Christina Back, General Atomics' vice president for nuclear technologies and materials, said avoiding repeated fuel deliveries would be valuable in remote locations. She questioned the usefulness of a 1-megawatt reactor, arguing that bases need more power, and said the many days needed for setup and dismantling make combat-zone use impractical.

Shivanandan raised a different installation concern. She criticised unnamed competing designs that require holes at least 50 feet deep, arguing that burying a reactor would leave the customer with a permanent nuclear site. The disagreement concerns both how much power customers need and how readily they could move an installation.

US Army seeks domestic proof before any possible remote deployment

Waksman said none of the microreactors under discussion had operated at full power. Brief operation at low power is not the same as sustained full-power operation, he cautioned. Safe field performance and affordability remain to be demonstrated.

We don’t have any plans at this time to take these into conflict zones.

The Army is considering what later deployment to harsher locations, including Arctic positions and Pacific islands, would require. Waksman said safe, affordable operation in the contiguous United States must come first.

Space development is a separate effort. In September, the US Department of Defense awarded Antares $161 million to develop its R1-S reactor integrated with spacecraft for flight certification. Antares founder and CEO Jordan Bramble aims to install that space version on the Moon as early as 2030; the award funds development, not an achieved lunar deployment.

A nearer deployment target is Antares' planned installation of its 1-megawatt R1 reactor at the Army’s Fort Bragg in North Carolina by September 2028. That remains an installation goal, while Project Janus’s domestic programme is intended to establish whether microreactors can reliably and affordably power critical military operations.