The 20-foot shipping container is the most standardized object in world trade. Sneakers, engine blocks, flat-pack furniture: anything that fits the box moves by truck, rail or ship without anyone redesigning a thing. A Houston company called Deployable Energy has now built a nuclear reactor to those exact dimensions, and the reactor has already run a self-sustaining chain reaction.
The product is called the Unity Nuclear Battery, and the name undersells the physics. Each unit is a 1-megawatt-electric fission reactor, water-moderated and helium-cooled, packaged into a standard 20-foot (6-meter) box that travels on ordinary trucks, trains and ships.
On August 18, the state of Utah signed a memorandum of understanding with Deployable to work out whether and where Unity units could be sited across the state. The demonstration reactor had gone critical at Idaho National Laboratory seven weeks earlier, roughly 150 days after the project kicked off.
The “battery” is a real fission reactor
Plenty of devices get called nuclear batteries, and most of them are radioisotope generators: lumps of decaying plutonium or strontium that trickle out watts for decades, the kind NASA bolts to space probes. Unity is not that. Unity runs a controlled chain reaction in uranium fuel, the same physics working inside every commercial power plant in the country.
The battery framing describes how Deployable wants you to use the thing. The company builds the reactor in a factory, ships it sealed, plugs it in where power is needed, and swaps cores on a five-year refueling cycle, with spent fuel handled at a centralized offsite facility, per its published specs. A single box makes 1 megawatt. Deployable says identical modules stack into arrays of several hundred units, and the thermal output can be liquid-cooled, air-cooled or drawn straight off as process heat for industry.
For scale, Aalo Atomics is packaging 10-megawatt reactors into 50-megawatt pods aimed at AI data centers. Deployable went the other way, down to 1.
The box went critical on a deadline set by executive order
Executive Order 14301, signed in May 2025, handed the Department of Energy a strange and very specific homework assignment: get at least three brand-new test reactors to criticality by July 4, 2026, the country’s 250th birthday. The DOE ran two fast tracks under it, the Reactor Pilot Program for test units built outside the national laboratories and the Nuclear Energy Launch Pad through the National Reactor Innovation Center at Idaho National Laboratory.
The deadline held. Antares Nuclear’s Mark-0 went critical at Idaho on June 4. Valar Atomics’ Ward 250 followed at the Utah San Rafael Energy Lab, announced June 18. Unity sustained its chain reaction on June 30, the first criticality logged under the Launch Pad initiative, and Deployable announced it on July 1. Aalo’s Aalo-X crossed at 12:20 a.m. on the Fourth itself.
Four reactors made a three-reactor deadline.
“Achieving criticality in roughly 150 days is a remarkable accomplishment,” Idaho National Laboratory director John Wagner said in Deployable’s announcement. Criticality is the point where the neutron bookkeeping balances: each generation of fissions kicks off exactly enough neutrons to start the next, no outside source required. Unity’s first run used a full-scale core load, and the phased test campaign in Idaho still has to validate reactor physics, load following, inherent safety and full-power operations before the conversation turns to paying customers.
The fuel is the genuinely clever part
Most microreactor startups designed themselves into a fuel problem. Their cores call for high-assay low-enriched uranium, HALEU, material enriched between 5% and 20% that remains scarce in the United States: Antares got its TRISO fuel fabricated on a conditional commitment of the government’s own HALEU stock. Deployable skipped the queue.
Unity runs on uranium dioxide enriched to 4.95%, per the company’s technical specifications, just under the 5% ceiling that commercial reactor fuel has sat below for decades. Every fabricator already serving America’s power plants handles that material today. Bobby Gallagher, Deployable’s co-founder and CEO, credited the existing fuel supply chain as one of the things that made the 150-day sprint possible.
The coolant is helium, the moderator is ordinary water, and the listed materials are deliberately unexciting industrial stock rather than exotic alloys. Deployable treats unexciting as the pitch. A reactor made of parts factories already produce is a reactor that fits on an assembly line, which is the entire business model.
Unity also parts ways here with the Pentagon’s Pele microreactor, the transportable unit whose 40,000 fuel compacts have been sitting in Idaho waiting for final assembly in Virginia. Pele is a one-off Defense Department prototype built for a single demonstration. Unity is pitched as a catalog product on standard oxide fuel, drawn for a production line rather than a program office.
So what did Utah actually sign?
Utah signed a framework, and an explicitly non-binding one. The August 18 document commits Deployable and the Utah Office of Energy Development to cooperation and information sharing across research, testing, demonstration and eventual commercial deployment. The paper approves no construction, licenses no reactor and obligates nobody to buy anything.
Emy Lesofski, who directs the Office of Energy Development and advises Governor Spencer Cox on energy, called the agreement “another step towards an abundant energy future that is reliable, secure and clean.” Cox met Deployable’s leadership in July, posing for the kind of group photo governors reserve for companies they intend to keep around.
Utah has been collecting nuclear paperwork at a steady clip. Governor Cox launched Operation Gigawatt in October 2024 to double the state’s power production inside ten years, with demand pressure coming from population growth and power-hungry data centers. The state signed an MOU with Idaho National Laboratory in April 2025, another with microreactor developer NuCube for a test unit at the San Rafael Energy Lab in Orangeville, and another with TerraPower.
Valar’s Ward 250 then went critical at that same San Rafael site in June, so a reactor startup has already run a chain reaction on Utah ground under this push. Utah’s grid, through all of it, still carries zero commercial nuclear generation. The state does run the country’s only operating uranium mill, and America’s newest reactor currently answers to a Canadian address.
The same box is getting sea legs
Deployable spent the two weeks before the Utah signing stacking up partners. Hornbeck Offshore, which operates high-spec offshore service vessels across the Gulf and Latin America, signed its own MOU with Deployable on August 17 covering five maritime markets: inland waterways, offshore vessels and platforms, national-security logistics and autonomous vessels, power barges, and floating data centers. Hornbeck also put in money as a strategic investor, on undisclosed terms. Solaris Energy Infrastructure, the NYSE-listed Houston outfit renting mobile turbine fleets to data centers, disclosed an equity stake of its own this summer.
Deployable says it is the only commercial microreactor developer holding both an initial criticality and an Approval in Principle from a maritime classification society, and the maritime pitch leans on that pairing. Hornbeck and Deployable are targeting at least a 20% cut in total cost of ownership against conventional marine diesel or grid power, per the joint announcement, with classification, licensing and engineering mapped as a phased program. A power plant that ships like cargo can, in principle, float like cargo.
Zero Unity units have been sold, sited or licensed for commercial operation anywhere. The Utah MOU binds nobody, the Hornbeck program starts with feasibility studies rather than shipyards, and the Idaho test campaign still has full-power operations ahead of it.
Nuclear Engineering International reports that a full-power demonstration of Unity is slated at Idaho National Laboratory in 2027, and Deployable’s own spec sheet quotes six-month delivery lead times starting in 2030. The box went critical on June 30, 2026. Utah’s signature is dated August 18.
