The Department of Defense broke ground on Project Pele at Idaho National Laboratory on September 24, 2024, launching the Pentagon’s first transportable nuclear microreactor and setting the stage for a test that could reshape how the U.S. military and, eventually, civilian communities generate power in remote locations. The reactor, manufactured by BWXT Advanced Technologies, is scheduled to begin assembly in February 2025 and ship to INL for testing in 2026. If the demonstration succeeds, it will validate a class of small, mobile nuclear systems that the military has pursued for years but never fielded at scale.
From Concept Selection to Construction at INL
Project Pele did not appear overnight. The Pentagon’s Strategic Capabilities Office selected two prototype designs in March 2021, describing the effort as a fourth-generation nuclear system intended to reduce fuel logistics, bolster energy resilience, and cut carbon emissions for deployed forces. A Record of Decision published in April 2022 cleared the way for final construction after federal analysis showed that radiological and nonradiological risks to workers and the public would remain low under normal operations and credible accident scenarios. Program manager Jeff Waksman later briefed the Nuclear Regulatory Commission on design parameters, emphasizing that the microreactor is meant to be transported by standard military assets and restarted quickly after relocation.
The September 2024 groundbreaking at INL converted those years of planning into physical construction. The Department of Defense described the unit as a mobile system for resilient power that can operate in remote and austere environments where diesel convoys are vulnerable or unreliable. BWXT Advanced Technologies is manufacturing the reactor, with assembly scheduled to begin in early 2025 and shipment to Idaho planned for 2026. According to Idaho National Laboratory, the first TRISO fuel shipment for Pele arrived in late 2025, a milestone the lab said reflected a tightly coordinated partnership between federal sponsors and private suppliers. TRISO fuel (tiny coated particles engineered to withstand extreme heat, radiation, and corrosion) was chosen to limit the chance of fuel failure in a reactor designed to be loaded onto trucks, shipped across continents, and restarted repeatedly over its service life.
The DOME Test Bed and a Second Microreactor Track
Project Pele will not test in isolation. The Department of Energy released an environmental assessment for the DOME (Demonstration of Microreactor Experiments) test bed at INL, a facility that repurposes the former EBR-II containment to host microreactors up to 20 megawatts thermal. The draft assessment, cataloged as DOE/EA-2268, evaluates how the site will manage radioactive waste, control potential releases, and address environmental justice concerns for nearby communities. By reusing existing nuclear infrastructure rather than building new containment from scratch, DOE aims to compress schedules and lower costs while still bounding worst-case accident consequences for a range of advanced designs.
Running on a parallel track at INL’s TREAT facility is MARVEL, a DOE microreactor that has completed its final design step with a report supported by more than 200 technical documents. MARVEL is a much smaller machine, about 85 kilowatts thermal with sodium-potassium coolant, intended for integration into experimental microgrids and other civilian applications. A separate utilization plan lays out how MARVEL will test remote operation, autonomous control, and new business models for distributed nuclear power. The overlap with Pele matters because both projects will generate operational data on fuel performance, control systems, and emergency procedures. If DOME ultimately hosts multiple microreactors, the shared environmental monitoring and safety record could reduce duplicative federal reviews and create a common evidence base for both military and civilian deployments.
NRC Licensing and the Regulatory Bottleneck
Building a reactor is one challenge; licensing it for broader use is another. The Nuclear Regulatory Commission currently relies on existing pathways under 10 CFR Parts 50 and 52 to evaluate microreactors, even though those rules were written for large, site-built commercial plants. These frameworks require exhaustive site-specific analyses, voluminous safety documentation, and lengthy hearings that can stretch over many years. That structure sits uneasily with the concept of a factory-fabricated reactor intended to be moved between locations as missions change, since each new site could theoretically trigger another full review.
To address the mismatch, the NRC has proposed a new Part 53 rule tailored to advanced reactors and has outlined an Integrated Microreactor Activities Plan that contemplates a dedicated pathway for factory-built and low-consequence designs. Until that rulemaking is complete, however, every deployment beyond tightly controlled testbeds like INL faces a regulatory bottleneck. Developers must either fit novel concepts into legacy categories or pursue case-by-case exemptions, both of which add uncertainty and cost. For the Pentagon, that means Pele’s first-of-a-kind demonstration will likely proceed under federal defense authorities and DOE oversight, but any follow-on units intended for commercial partners, allied bases, or domestic emergency response would need to navigate civilian licensing processes that are still being adapted to microreactor realities.
Military Demand, Civilian Spillover
The defense community’s interest in mobile nuclear power is rooted in logistics and vulnerability. Forward operating bases and remote radar sites often rely on long fuel convoys that are expensive, carbon-intensive, and exposed to attack. A successful Pele demonstration could show that a single microreactor can displace millions of gallons of diesel over its lifetime, while providing stable power for command centers, communications, and directed-energy systems. The Department of Energy has emphasized that the unit will be assembled and tested at INL before any field use, underscoring the importance of rigorous validation before the military relies on nuclear assets in dynamic environments.
Civilian stakeholders are watching closely because the same attributes that appeal to the Pentagon (compact size, transportability, and inherent safety features) could help decarbonize remote communities, mines, and research stations that currently depend on diesel or coal. If Pele proves that a microreactor can be shipped, installed, and operated with a relatively small on-site staff, it will strengthen the case for commercial models that pair nuclear heat and power with microgrids, hydrogen production, or data centers. At the same time, the project highlights enduring challenges: spent fuel management, cybersecurity for autonomous systems, and community acceptance of nuclear facilities that may arrive by truck rather than be built over a decade-long public process. How regulators, developers, and host communities resolve those questions at INL will shape whether microreactors remain niche military tools or become a broader pillar of the future energy system.
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*This article was researched with the help of AI, with human editors creating the final content.
