U.S. Army Launches Full-Scale Push for Base-Level Nuclear Power With Janus Microreactors

The U.S. Army has taken a major step toward putting tiny nuclear reactors on some of its largest installations, formally moving the Janus microreactor program from concept into execution by naming nine candidate bases and asking industry to submit designs through the Defense Innovation Unit (DIU).

The announcement, made on November 18, 2025, reflects a blunt assessment inside the Pentagon: as digital warfighting systems, AI-enabled command networks, and air-defense radars drive power demand higher, the aging civilian grid and diesel logistics can no longer be treated as reliable backstops for critical missions.

Nine Installations in the Running

Under the new plan, the Army has identified nine installations that could host the first wave of microreactor power plants under Janus:

• Fort Benning, Georgia

• Fort Bragg, North Carolina

• Fort Campbell, Kentucky

• Fort Drum, New York

• Fort Hood, Texas

• Fort Wainwright, Alaska

• Holston Army Ammunition Plant, Tennessee

• Joint Base Lewis-McChord, Washington

• Redstone Arsenal, Alabama

These sites were selected after a comprehensive analysis and on-the-ground assessments that examined mission criticality, current energy shortfalls, grid resilience, local infrastructure, and environmental and technical constraints. The list does not guarantee that all nine will receive reactors; final locations and quantities will be decided during the acquisition process based on technical feasibility, site suitability, and available resources.

Turning Nuclear Power Into Mission Assurance

The Janus Program is the Army’s flagship effort to create secure, resilient, and reliable on-site power for U.S. military bases, in line with Executive Order 14299: “Deploying Advanced Nuclear Reactor Technologies for National Security.”

Rather than building government-designed reactors, the Army plans to buy commercial microreactors through a milestone-based contracting model, managed in partnership with DIU. Private vendors will design and build microreactor power plants (MPPs) capable of:

• Providing up to ~20 megawatts electric (MWe) per unit

• Powering both fixed installations and non-permanent, expeditionary operations

• Supporting “islanded” operation if the civilian grid fails

• Offering high uptime and the ability to black-start key systems after an outage

The Army’s near-term goal is to field at least one operational demonstration microreactor on a U.S. base by around 2030, while EO 14299 directs the Department of War to begin operating an Army-regulated reactor on a domestic installation no later than September 30, 2028.

Why the Army Wants Microreactors

Behind the bureaucratic language is a simple operational problem:

• Rising demand: Modern formations depend on sensors, radars, AI processing, space links, and cyber-defense systems that pull far more power than legacy command posts.

• Fragile grids: Extreme weather, cyberattacks, and chronic under-investment have made U.S. civilian grids less reliable, especially in remote areas like Alaska.

• Fuel logistics risk: In a conflict against a near-peer adversary, moving diesel by road, sea, and air is slow, vulnerable, and expensive.

Janus is meant to transform nuclear energy from a distant, strategic asset into a direct tool of mission assurance—so that air defense, missile warning, command-and-control and cyber units keep fighting even if the surrounding grid goes dark.

Officials emphasize that next-generation microreactor designs are “safe by design, not by emergency intervention”—relying on passive safety features, simplified systems, and factory-sealed cores that are meant to reduce the risk of accidents and limit waste volumes.

DIU’s Call to Industry

To move from concept to concrete hardware, the Army has asked the Defense Innovation Unit to run a rapid competition using its Commercial Solutions Opening (CSO) process and Other Transaction Authority (OTA) contracts—tools designed to pull in non-traditional defense companies and nuclear startups.

The newly released Area of Interest (AOI) seeks proposals for:

• Microreactor power plants up to ~20 MWe

• Designs able to operate 24/7 with minimal on-site staff

• Systems that meet stringent nuclear safety, security, and safeguards requirements

• Concepts that can scale across multiple bases if the first wave succeeds

According to the American Nuclear Society’s summary of the AOI, vendors have until mid-December 2025 to submit initial concepts. Selected companies would then receive milestone-based contracts, with payment tied to design, licensing, construction and testing achievements rather than traditional cost-plus models.

Janus will build on parallel DoD initiatives, including DIU’s broader Advanced Nuclear Power for Installations (ANPI) effort, which has already pre-qualified firms like BWXT, Westinghouse, Kairos Power, Oklo, X-energy, Radiant Industries and others to demonstrate microreactor technologies for military and commercial customers.

Lessons From Project Pele and Earlier Pilot Efforts

Janus does not start from scratch. The program is explicitly designed to leverage lessons from “Project Pele,” a 1.5-megawatt gas-cooled microreactor whose core is now under construction as a demonstration for the Department of Defense.

Like Pele, Janus reactors are expected to:

• Use advanced fuels (often high-assay low-enriched uranium, or HALEU)

• Be factory-fabricated and transportable, rather than stick-built on site

• Operate for years between refueling, reducing logistics burden

But where Pele is primarily a single demonstration, Janus is deliberately structured as a fleet-building program, with the potential for dozens or even hundreds of units across Army and possibly other DoD installations if the first deployments meet performance and safety targets. 

Local Communities, Safety, and Power-Sharing

Army officials stress that microreactor projects will be self-contained, heavily protected, and tightly regulated in coordination with the Department of Energy and its national laboratories. All projects, they say, will comply with federal, state, and local regulations, and the Army “does not anticipate significant impacts on installation land use.”

A key political and economic question is whether excess power from these reactors can legally and practically be exported to surrounding civilian grids—for example, to support local communities or energy-hungry data centers near large bases. Analysts and Army officials acknowledge that this would require Congress to clarify overlapping laws governing military, commercial, and civil nuclear facilities.

In the meantime, the service is promising public engagement, transparency, and detailed timelines for each installation as designs are selected and environmental reviews proceed.

A High-Risk, High-Reward Energy Bet

Supporters inside the Pentagon argue that on-base microreactors could give U.S. forces a decisive edge in any conflict where cyber operations, missile salvos and electronic warfare threaten national grids and fuel pipelines. They also see Janus as a way to jump-start the domestic advanced nuclear industry, creating a guaranteed early market for reactor startups that are also targeting AI data centers, industrial hubs and remote communities. 

Critics, however, warn of:

• Fuel supply bottlenecks, especially for HALEU

• The complexity of siting and securing nuclear facilities on multiple bases

• The challenge of coordinating oversight between DoD, DOE, the Nuclear Regulatory Commission and state regulators

For now, the Army’s message is that the status quo is no longer acceptable. With Janus, it is betting that small, hardened nuclear reactors can become as essential to modern warfighting as satellites, cyber units, and advanced air defenses.

If the program stays on schedule, the next decade could see something unprecedented in U.S. history: front-line combat power quietly underwritten by a network of compact nuclear plants, humming away behind the fence lines of American bases.