Project Janus

Problem Statement

Ensuring consistent, resilient energy across military installations and operational theaters has become an increasingly complex challenge for the U.S. military. Aging infrastructure, dependence on vulnerable civilian power grids, complex liquid fuel logistics, and rising energy demands from advanced technologies all threaten mission assurance. Frequent electricity outages, grid disruptions, and limited backup capacity jeopardize critical systems responsible for command, control, communications, and logistics. This directly undermines readiness, training, and operational effectiveness. These vulnerabilities underscore the urgent need for secure, scalable, and independent energy solutions that ensure continuous power for the warfighter to operate anytime, anywhere, regardless of external grid instability or supply chain disruptions.

The U.S. Army, alongside the Defense Innovation Unit, seeks to prototype Microreactor Power Plant(s) (MPPs) capable of developing a suite of advanced nuclear power plant energy solutions to meet the needs of the U.S. Department of War (DoW). These MPPs will leverage recent advances in the nuclear industry to provide continuous and reliable power in all DoW scenarios and will be demonstrated on a military installation within the United States by 2030.

Background

On 23 May 2025, four executive orders (EOs) were issued that aimed at modernizing America’s nuclear energy posture, with direct implications for the Army and the broader DoW. In particular, EO 14299 Deploying Advanced Nuclear Reactor Technologies for National Security, states that “it is the policy of the United States to ensure the rapid development, deployment, and use of advanced nuclear technologies to support national security objectives, such as the protection and operation of critical infrastructure, critical defense facilities, and other mission capability resources.” These orders represent a strategic shift towards immediately and impactfully leveraging advanced nuclear technologies. Meeting the objectives of EO14299 requires a focus on both installation and operational energy goals through a coordinated prototype program that leverages MPP technologies to address the Department of War’s energy needs. 

Project Approach

The broader Department of the Army’s Janus program objective is to develop a suite of prototype solutions for MPPs that can supply power for both installations and non-permanent operations. The Janus project approach under the DIU CSO will use an iterative prototype development process to provide a clear path to transition of the successful commercially demonstrated technology solutions. “Suite” refers to the DoW’s intent to select multiple reactor designs for the OTA Agreement, each to be paired with an Army installation by the Army after contract award. This will involve prototyping a First of a Kind (FOAK) MPP under the Army’s regulatory authority, followed shortly after by a Second of a Kind (SOAK) MPP, also using the Army’s regulatory authority. The Department is seeking fission-based solution sets for installation and defense purposes. 

Vendors will be paired with Army installations after the OTA contract award. Vendors will develop their FOAK prototype for demonstration on that installation and commence design of the SOAK prototype near the end of FOAK design. The SOAK prototype is expected to build on lessons learned from the FOAK and include design changes from the FOAK prototype, through iterative prototyping. 

Vendor solutions submitted under the AOI are highly encouraged to use the FOAK and SOAK approach in their proposals, and discuss the path from SOAK to Nth-of-a-kind production. Solutions may utilize the operating life of both the FOAK and SOAK MPPs in series to reach the 30-year lifetime power generation, assuming continuity of power across the 30-year period. 

The Army will be announcing the selection of the initial group of installations for the Janus project MPP prototypes at a later date. Vendors are prohibited from contacting or responding to queries from the installations regarding any aspect of CSO HQ084520SC001 or the Janus project. Vendors who do not comply with the prohibition may be removed from participation in the Janus Project. 

Project Objectives

The Department is seeking solution briefs for the full lifecycle of MPPs that would notionally start operations at an Army installation located in the United States before the end of calendar year 2030. Solution briefs should include all stages of an MPP’s lifecycle: design, testing, regulation, construction, operations, deconstruction, and returning the site to an unrestricted release status.

The objectives of the prototype include: 

• Provide mission assurance through energy resilience for a range of defense applications. 
• Assemble and operate prototype MPPs on military installations within the United States to demonstrate the capability of the MPP designs to provide safe, secure, reliable, and environmentally compliant electricity and thermal energy (if needed) in support of readiness goals for mission critical assets.
• Engage with the government and privatized distribution providers, transmission providers, and commodity providers currently serving U.S. Military installations to facilitate seamless and resilient energy regardless of commercial grid conditions.

Final solutions will follow a process under the U.S. Army Regulatory Authority for the entire lifecycle. The U.S. Army’s regulatory authority is derived from section 91b of the Atomic Energy Act (42 U.S.C. § 2121(b)), as implemented pursuant to the Presidential Directive of 23 September 1961. Vendors will follow the Army regulatory process as documented in AR 50-7 (2016), although additional guidance will be provided during Phase 2 and throughout the FOAK design. AR 50-7 can be found at: https://armypubs.army.mil/epubs/DR_pubs/DR_a/pdf/web/r50-7_Web_FINAL.pdf. 

Awarded vendors will be given opportunities to provide feedback on gaps in Army regulatory processes as additional regulatory guidance is provided. Additional regulatory requirements, such as transportation of nuclear material on public highways, should be addressed by Vendors during their proposals.

Reviews and implementation during the MPP prototype development process will include an integrated and phased approach to compliance with planning and design, planning and construction, architecture and engineering, building construction, environmental, operating, safety and physical/cyber protection, emergency response planning, deconstruction, and spent fuel management requirements. 

A successful MPP prototype will provide a sound and demonstrated technological solution for commercial operations. A successful prototype will complete fuel load and testing phases and will be permitted by the Army Regulator to begin normal operations. The OTA prototype will transition to unrestricted operations as a COCO MPP with a Power Purchase Agreement (PPA), production OTA, or other Federal Acquisition Regulation (FAR) based contract.

Desired Solution Features 

Desired solution features include the following attributes and capabilities: 

• Incorporates nuclear fuel that is enriched to 20% or less U-235 and that is legal for defense purposes. The fuel must be qualified, available, and fabricated on a timeline that will meet program timelines.  
  • Defense-purpose feedstock may be made available as Government Furnished Equipment (GFE) for FOAK and SOAK MPPs through an Army fuel allocation process. If feedstock is provided as GFE, vendors will be responsible for transportation, blending, and fabrication of the fuel. 
  • Vendors should address the implications of a) the Government not providing feedstock as GFE, b) of the Government providing feedstock as GFE for only the first fueling, and c) the Government providing feedstock as GFE for the operational life of the MPP.
• Capable of producing electrical power in the range of kW-level up to 20MWe (up to 60 MWth). Capable of local control and dispatch and integrated to the greatest extent practicable into existing infrastructure, operations centers (if applicable), workflows, and operations and maintenance systems. 
• Capable of startup/shutdown and monitoring operations both with and without commercial power availability (both black start and grid-connected start capability). 
• Capable of MPP operations with a commercial power connection, and an alternative credited independent power source as a backup. 
• The MPP should be operated only from the control room located within the Army installation (remote or wireless operation is not allowed). 
  • MPPs with remote maintenance and diagnostics capabilities that comply with relevant cybersecurity U.S. Government standards, e.g., NIST 800-171 Rev. 2 for Federal Contractors, may be considered. 
  • The MPP control room must be designed to accommodate two operators, with space for an additional person, at a minimum. 
• The MPP design should include passive safety features to the extent practical to ensure MPP key safety functions are satisfied under all conditions, states, and modes. 
• Radiation exposure at the MPP site boundary should not exceed the limits provided in 10 CFR 20 during routine operations. Proposals must sufficiently account for relevant factors, including sky shine, emissions from activated site materials, and surrounding buildings at various elevations around the site boundary. 
• The MPP design must address Natural Hazard Phenomena, including seismic loads, external floods, and other potential hazards.
• The MPP design must have clearly articulated systems and safety case approaches, including an initial set of proposed design criteria and design safety strategy.
• Vendor strategy and capability to continuously provide full power supply for up to 30 years, including operations, maintenance, sustainment, and refueling activities. 
  • There are no restrictions on the proposed strategy to achieve 30-years of continuous power (e.g., refueling or ‘replaceable’ modules to maintain continuity of operations). 
  • The overall lifecycle strategy of the MPP by the Vendor will be evaluated and must include associated costs/risks with the proposed strategy for long-term operations.
• Non-core irradiated material should be removed or qualified for unrestricted release within 2 years upon completion or termination of the power production contract. An initial irradiated material disposal plan, along with an associated finance structure, must be approved by the Army before design permitting. 
• Irradiated core material should be removed from the site notionally within 5 years of completion or termination of the power production contract, or as otherwise agreed upon by the Army. An initial core decommissioning plan, along with an associated finance structure, must be approved by the Army before MPP operations are permitted. 
• A target site area should be sized appropriately for FOAK (and SOAK if co-located) to ensure compliance with Federal radiation limits in 10 CFR 20 and the anticipated Seismic Design Category. Selected Vendors will be paired with an installation post-OTA award.
• Reasonable and appropriate safety, physical, cyber, and safeguards measures should be implemented in the design consistent with best practices. Army-specific requirements will be provided to vendors invited to participate in Phase 2 Pitches. 
• In addition to the above desired solution features, solutions must address the aspects below: 
  • A nuclear supply chain for nuclear-grade equipment that is clearly identified and credibly available to supply equipment to meet the notional timeline. The nuclear supply chain identified must meet defense-purpose limitations; any part of the nuclear supply chain reliant on international sources must be identified and mitigated with a plan approved by the Army.
  • Technology Readiness Level (TRL) and Manufacturing Readiness Level (MRL) for equipment included in the design. The TRL and MRL readiness levels will be evaluated in depth during Phase 2 Pitches. 
  • Identified gaps in available Computational analytical tools, Codes, or Standards accepted for nuclear use. Identified analytical tools, Codes, or Standards for which the design will operate outside the approved range 
  • (e.g., the MPP operates at a higher temperature than existing foundational data).
  • Identified gaps in available material performance data for safety or reliability-related equipment under anticipated operating conditions.
  • Plans and approaches to move from FOAK to SOAK, to Nth-of-a-Kind development and production. Plans to commercialize or develop commercial versions of proposed MPP prototype designs.
  • Long-term plans for fuel acquisition and manufacturing, including the status of negotiations or agreements with miners, enrichers and/or fabricators.