Project Janus Explained: Why the U.S. Army Wants Microreactors on Military Bases by 2028

The U.S. Army's Janus Program marks a major shift in how the Department of Defense is thinking about energy resilience. As military installations become more dependent on power-hungry systems such as artificial intelligence, advanced communications, autonomous platforms, command-and-control networks and air defense systems, the Army is looking for energy sources that can operate independently from vulnerable civilian grids.

Project Janus is the Army's effort to deploy commercial nuclear microreactors at domestic military installations by 2028, creating a new model for secure, high-density and resilient base power. This article examines what exactly Poject Janus involves, why it's needed, and how it differs from traditional defense acquisition.

What is Project Janus?

Project Janus is the U.S. Army's program to deploy commercial nuclear microreactors on military bases. These microreactors are smaller than traditional nuclear power plants and are designed to provide reliable, 24/7 power for critical installations and mission systems.

The goal is not simply to add another power source. It is to give the Army a way to keep essential operations running during grid disruption, cyberattack, extreme weather, fuel supply interruptions or future conflict.

IDGA's latest report, The Army's Janus Program Moves Nuclear Power to the Front Lines of Energy Security, explains things in more detail: The Janus Program is aiming to deploy commercial nuclear microreactors across U.S. military installations by 2028, and in 2026 the program is expected to move into its next stage by deploying microreactors across nine pre-selected Army installations.

What is a nuclear microreactor?

A nuclear microreactor is a small, factory-built reactor designed to provide compact, reliable power. While definitions vary, microreactors are generally much smaller than conventional nuclear reactors and are often discussed in the 1 MW to 20 MW range for defense and remote power applications.

For the Army, that power range is important because military bases and mission systems need constant electricity, but not every installation requires a full-scale power plant. Microreactors could provide localized power for command nodes, radar systems, AI infrastructure, communications, weapons systems, logistics hubs and critical base operations.

Reuters has reported that the Department of Defense is accelerating development of microreactors through initiatives such as Project Pele and the Janus Program, with the reactors intended to provide off-grid, 24/7 power for military bases and operations.

Why does the Army want microreactors on military bases?

The Army's interest in microreactors is being driven by a simple operational reality: modern military power demand is increasing, while the civilian grid is becoming a more visible vulnerability.

Military installations rely on electricity for communications, cyber operations, data processing, base security, air defense, logistics, training, maintenance and emergency response. As the Army adopts more AI-enabled tools, electrified platforms and digitally connected systems, that demand will only grow.

Military leaders also increasingly view the civilian power grid as a strategic vulnerability. The White House reinforced this concern in its Executive Order on Deploying Advanced Nuclear Reactor Technologies for National Security, which identifies advanced nuclear power as a critical component of future defense infrastructure. 

The Janus Program is designed to address three core challenges.

First, energy resilience. Bases need to keep operating even if the local grid fails.

Second, mission assurance. Critical defense systems need reliable power during crises, attacks or natural disasters.

Third, strategic independence. The Army wants a power source that reduces dependence on long fuel supply lines or fragile infrastructure.

Key facts and dates: Project Janus timeline

Project Janus is moving quickly, largely because it is tied to a specific national security deadline.

May 2025: Executive orders were issued to accelerate nuclear power development and advanced reactor deployment.

October 2025: The U.S. Army launched the Janus Program.

November 2025: The Army identified nine candidate installations for initial microreactor deployment, according to IDGA's report.

2026: The Army aims to move from concept to execution by evaluating vendors, matching reactor designs to sites and accelerating acquisition through its partnership with the Defense Innovation Unit.

September 30, 2028: The Army is working toward having an Army-regulated nuclear reactor operational at a domestic military installation by this date.

Reuters reported that Janus is part of the Advanced Nuclear Power for Installations initiative and that the program aims to install a nuclear reactor on a military base by September 2028. The same reporting noted that microreactors are designed to provide off-grid power for military installations, communication networks, weapons systems and command nodes.

Which Army bases have been selected?

As IDGA's report states, the Army identified nine sites in November 2025 for the initial deployment of Janus Program microreactors. These sites were selected after analysis of mission-critical installations, energy requirements, resiliency gaps, power infrastructure, and environmental and technical considerations.

The listed sites include:

• Fort Benning
• Fort Bragg
• Fort Campbell
• Fort Drum
• Fort Hood
• Fort Wainwright
• Holston Army Ammunition Plant
• Joint Base Lewis-McChord
• Redstone Arsenal

The Army is now working to match specific reactor designs to these locations, making 2026 a potentially significant year for the program.

How Project Janus differs from traditional defense acquisition

One of the most important features of Project Janus is its commercial-first model.

Rather than owning and operating the reactors itself, the Army is working with private industry to develop commercially viable microreactors. Under this model, companies would design, build, own and operate the reactors, while the Army provides technical oversight, regulatory support and assistance across the nuclear fuel cycle.

This structure is intended to reduce government risk, accelerate deployment and encourage private-sector investment. The IDGA report compares the model to NASA's Commercial Orbital Transportation Services program, where NASA partnered with commercial firms to develop cargo transport to the International Space Station.

For defense energy, this is a major shift. The Army is trying to create a commercially scalable nuclear energy model that can support military resilience while also strengthening the domestic advanced nuclear industry.

The role of the Defense Innovation Unit

The Defense Innovation Unit is expected to play an important role in moving Janus faster than traditional defense acquisition timelines would normally allow.

The Army is working with DIU to accelerate microreactor acquisition through flexible procurement mechanisms such as Commercial Solutions Openings and Other Transaction Authority. These tools are designed to help the Department of Defense solicit, evaluate and contract with commercial technology companies more quickly.

That matters because microreactor deployment sits at the intersection of military energy security, nuclear regulation, private capital, fuel supply, site selection and industrial base development. A slow acquisition model could make the 2028 target difficult to meet.

The DIU-backed model gives the Army a better chance of moving at the pace of commercial innovation.

Project Janus vs Project Pele

Project Janus is not the Department of Defense's first attempt to use nuclear microreactors for military energy. It builds on earlier work under Project Pele, a Department of Defense initiative focused on a transportable microreactor for remote and austere environments.

Project Pele is important because it helped establish the technical and operational foundation for military microreactors. Janus is different because it focuses on domestic military installations and commercial operation.

In simple terms:

Project Pele is about demonstrating deployable nuclear power for military operations.
Project Janus is about placing commercially operated microreactors on U.S. military installations to strengthen base energy resilience.

Why 2028 is the key deadline

The 2028 deadline is important because it creates urgency across the Army, industry and the advanced nuclear supply chain.

The executive order directs the Department of War to establish a nuclear energy program of record and have an Army-regulated nuclear reactor operational at a domestic military installation by September 30, 2028.

That deadline means the Army must quickly resolve several difficult questions:

• Which reactor designs are mature enough?
• Which installations are technically and politically suitable?
• How will nuclear safety and regulatory oversight work?
• Who owns and operates the reactors?
• How will fuel be supplied?
• How will spent fuel and waste be managed?
• How will reactors integrate with base power systems?
• How will security and emergency planning be handled?

The 2028 target is ambitious, but it is also what makes Project Janus strategically important. It pushes the Army and industry to turn advanced nuclear from concept into deployed infrastructure.

The opportunity for industry

Project Janus could create a major opportunity for advanced nuclear companies, engineering firms, fuel suppliers, construction partners, grid integration specialists, cybersecurity providers and defense energy contractors.

The program's commercial-first model means the Army is likely to need industry partners that can demonstrate not only reactor technology, but also project delivery, safety, licensing support, fuel planning, lifecycle operations and integration with military base infrastructure.

Companies including BWXT, X-energy, Radiant, Westinghouse and Antares are already advancing microreactor projects under new regulatory pathways. For industry however, the opportunity is not just one Army contract. If Janus works, it could help validate microreactors for broader defense, infrastructure, data center, remote community and industrial power markets.

The challenges facing Project Janus

Despite its promise, Project Janus faces serious challenges.

The first is regulatory complexity. Nuclear projects require safety review, security planning and public trust.

The second is fuel supply. Many advanced reactor designs depend on high-assay low-enriched uranium, or HALEU, which remains a constrained supply chain.

The third is cost. Microreactors may offer resilience benefits, but early units are likely to be expensive compared with conventional power sources.

The fourth is site acceptance. Even if a base is technically suitable, local concerns around nuclear safety, waste and emergency planning could slow deployment.

The fifth is commercial maturity. Many microreactor companies are still moving from design and demonstration toward deployment.

While military backing is helping accelerate the U.S. microreactor race, high costs, licensing complexity and fuel supply limitations remain major challenges.

Why Project Janus could reshape defense energy strategy

Project Janus is important because it reframes energy as a warfighting enabler.

For decades, military energy planning has often focused on fuel logistics, grid reliability and emergency backup power. Janus points toward a different model: installations with localized, resilient, high-density power that can support advanced mission systems even if external infrastructure fails.

If successful, microreactors could support:

• AI-enabled command-and-control systems
• Air and missile defense infrastructure
• Communications networks
• Cyber operations
• Remote and Arctic installations
• Ammunition plants and industrial facilities
• Critical logistics hubs
• Base resilience during grid failure

This could be especially relevant as the U.S. military prepares for more contested operating environments, where adversaries may target energy infrastructure, communications networks and logistics systems long before direct combat begins.

Key takeaways

Project Janus is the U.S. Army's program to deploy commercial nuclear microreactors at military installations by 2028.

The program is driven by rising military energy demand, grid vulnerability and the need for constant, high-density power for critical mission systems.

The Army has identified nine candidate sites and is working to match reactor designs to installation needs.

Janus uses a commercial-first model in which private companies design, build, own and operate the reactors while the Army provides oversight and support.

The 2028 deadline is ambitious and will require rapid progress on acquisition, regulation, fuel supply, site preparation and commercial reactor maturity.

For industry, Project Janus could become one of the most important defense energy opportunities of the decade.

FAQs

What is Project Janus?

Project Janus is the U.S. Army's program to deploy commercial nuclear microreactors at domestic military installations to improve energy resilience and mission assurance.

Why does the Army want microreactors?

The Army wants microreactors because they can provide reliable, high-density, off-grid power for critical installations and mission systems during grid outages, cyberattacks, extreme weather or conflict.

When will Project Janus deploy microreactors?

The Army is working toward having an Army-regulated nuclear reactor operational at a domestic military installation by September 30, 2028.

How many sites are involved in Project Janus?

Nine candidate Army installations have been selected for initial microreactor deployment.

What is the difference between Project Janus and Project Pele?

Project Pele focuses on demonstrating deployable nuclear power for remote or austere military operations. Project Janus focuses on commercially operated microreactors for domestic military installations.

What are the biggest challenges for Project Janus?

The biggest challenges include nuclear regulation, fuel supply, cost, site acceptance, reactor maturity, waste planning and integration with military base infrastructure.