How the Project Pele Microreactor Works

Pele is a transportable, high temperature, gas cooled reactor rated at 1.5 megawatts of electricity, fueled with 40,000 TRISO compacts that reached Idaho on November 5, 2025. It operates under Department of Energy authorization, outside Nuclear Regulatory Commission licensing. The prime contract, reported at about $300 million in June 2022, bought a prototype that now carries a three year schedule slip.

In August 2023 the program manager stated a goal of a running reactor at Idaho before the end of 2025. In late summer 2026 BWXT crews installed the core barrel in Lynchburg, Virginia, and the reactor has not yet shipped. Anyone planning a remote site, a campus microgrid, or an investment in advanced reactor suppliers is reading that gap between a 2025 promise and a 2027 shipment, whether they know it or not.

What Went into the Pele Core and Why Does TRISO Matter?

The Pele core is built from TRISO fuel, in which each uranium kernel carries its own containment. A kernel roughly a millimeter across is coated with a porous carbon buffer, an inner pyrolytic carbon layer, a layer of silicon carbide, and an outer pyrolytic carbon layer. The silicon carbide acts as a pressure vessel the size of a grain of sand.

Thousands of those particles are pressed into compacts held in graphite, and the graphite slows neutrons and carries heat while a gas pulls that heat to the power conversion equipment. The uranium is high assay low enriched, which means above 5 percent and below 20 percent in uranium 235, and a 2022 program announcement reported that BWXT would make the fuel from material in the Department of Energy highly enriched uranium inventory. Public sources do not state the enrichment.

As a nuclear trained submarine officer, I learned that every component of a submarine reactor plant earns a shock and tilt qualification before it reaches the boat. The Pele plant ships as four 20 foot ISO containers, and BWXT states that it meets shock and vibration requirements for truck, train, and aircraft transport. That requirement is the engineering demand I would watch most closely, because a reactor that gets lifted, trucked, and reassembled has no shipyard behind it.

Why Is the Pele Schedule Slipping Toward 2028?

No public document assigns the slip to one cause, and the milestone record shows where the time went. The Department of Energy authorized long lead items in December 2022. The system design review finished in August 2024. Ground broke at the Critical Infrastructure Test Range Complex on September 24, 2024. Core fabrication started in July 2025, fuel production finished in November 2025, and core stacking finished in June 2026.

The June 2022 award allotted two years to deliver a prototype. An earlier plan called for transport to Idaho in 2026, and the current plan ships the reactor in 2027, fuels it, and runs it for three years. Formal testing arrives as early as 2027 and electricity as soon as 2028. First of a kind fabrication of both the fuel and the core sits underneath every one of those dates. The 40,000 compacts have waited at Idaho since November 5, 2025 for a reactor to receive them, and each month of delay extends that wait while the fuel plant, the reactor builder, and the test site carry fixed costs.

What Does the Pele Contract Cost Per Megawatt Hour?

The reported contract value divides out to about $7,610 per megawatt hour. At 1.5 megawatts of continuous output the prototype generates 13,140 megawatt hours a year, or 39,420 over three years, and $300 million divided by 39,420 is $7,610.

That number mixes development, tooling, fuel qualification, and demonstration with generation, so it prices a prototype and says nothing about a production unit. BWXT asserts that the plant offsets up to 1.5 million gallons of diesel each year and removes hundreds of fuel truck deliveries. A utility or base commander cannot test those claims against a unit price, because none has been published. The comparison that matters for a remote site is the delivered cost of diesel generation, including the fuel convoys, and a published Pele unit price would let a buyer run that comparison in an afternoon.

Who Regulates the Next Military Reactor?

Pele operates under Department of Energy authorization. Executive Order 14299, Section 3(a), requires an Army regulated reactor, because it directs the Secretary of Defense, through the Secretary of the Army, to commence operation of a nuclear reactor regulated by the United States Army at a domestic military base no later than September 30, 2028. Section 110(b) of the Atomic Energy Act, 42 U.S.C. § 2140(b), lifts the license requirement for military utilization facilities, and Section 3(d) of the order called for recommendations within 240 days on rules for operating and removing reactors and spent fuel on military installations.

BWXT is expected to build a high temperature gas cooled reactor called BANR at Fort Campbell, Kentucky under the Army Janus program. The public record shows no completed rulemaking that creates an Army regulator, and a contractor bidding on installation reactors prices that gap into the bid. Fuel supply adds a second gap: BWXT proposed a $500 million TRISO plant in Gillette, Wyoming with a 2030 in service target, and Section 5(b) of the order releases 20 metric tons of high assay low enriched uranium without building any fabrication capacity.

What Comes After Pele at Fort Campbell?

The next installment examines Section 3(d) of Executive Order 14299 and the recommendations on regulating Army reactors, and it will show which agency a Janus contractor will answer to when the reactor at Fort Campbell starts up. Anyone pricing a military microreactor bid, a fuel plant, or a supplier stake in 2026 needs that answer before the capital is committed. Subscribe to The Innovation Attorney on Substack to receive it the day it publishes.

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