US Meets Its July 4 Nuclear Goal as Deployable Energy's Unity Becomes the Third Advanced Reactor to Reach Criticality

Overview

Deployable Energy said on July 1 that its Unity demonstration reactor had reached initial criticality at the National Reactor Innovation Center at Idaho National Laboratory, making it the third advanced reactor to go critical under U.S. Department of Energy authorization before the July 4 deadline set by a 2025 executive order, according to Deployable Energy. With Unity, “the US has achieved the presidential goal set last year of three microreactors under Department of Energy authorisation to achieve initial criticalities by 4 July 2026,” World Nuclear News reported. The Department of Energy said the achievement met the goal President Trump set of delivering three advanced reactor criticalities, according to the Department of Energy.

What We Know

Unity is a “1 MWe water moderated, gas cooled” deployable nuclear battery that reached criticality roughly 150 days after the project kicked off, according to Deployable Energy. The demonstration was the first criticality under the DOE’s Nuclear Energy Launch Pad initiative, Deployable Energy said. World Nuclear News also described Unity as a 1 MWe water-moderated, gas-cooled microreactor.

“Achieving criticality in roughly 150 days is a remarkable accomplishment,” said Dr. John Wagner, INL Laboratory Director, according to Deployable Energy. Bobby Gallagher, co-founder and CEO of Deployable Energy, said the milestone “demonstrates the dedication of our team and moves us one step closer to delivering reliable, resilient, and deployable nuclear energy solutions,” per Deployable Energy.

The company plans a phased testing program to validate reactor physics, load following, inherent safety, and full-power operations, work it said would support future licensing and commercialization, according to Deployable Energy.

Completing the Trio

The Unity milestone completed a set of three criticalities under the program. Antares Nuclear’s Mark-0 was the first, reaching criticality in early June at Idaho National Laboratory, according to World Nuclear News — a result The Machine Herald previously covered as the first private reactor to go critical under the pilot program.

Valar Atomics’ Ward 250 followed as the second, achieving criticality on June 22 at the Utah San Rafael Energy Lab in Emery County, Utah, according to World Nuclear News. It was the first DOE-authorized reactor built and operated outside the national laboratory system, World Nuclear News reported, and the Department of Energy celebrated it as the second advanced reactor to achieve criticality under the Reactor Pilot Program, according to the Department of Energy. Ward 250 is a 5 MW TRISO-fueled, helium-cooled, graphite-moderated reactor of a Gen IV high-temperature gas reactor design, per World Nuclear News. “Nine months ago, this was an empty site. Today, there’s a critical reactor on it, built and operated by the Valar team,” said Isaiah Taylor, founder and CEO of Valar Atomics, according to World Nuclear News. The airlift that carried Ward 250 to Utah was the subject of earlier Machine Herald coverage of the race to July Fourth.

The Program

The three criticalities fall under the DOE Reactor Pilot Program, which stems from the “Reforming Nuclear Reactor Testing at the Department of Energy” executive order signed by President Donald Trump in May 2025, according to World Nuclear News. That order set a goal “to construct, operate, and achieve criticality of at least three test reactors using the DOE authorisation process by July 4, 2026,” World Nuclear News reported. Energy Secretary Chris Wright said, “America’s nuclear renaissance is underway because of President Trump’s bold vision and ambitious goals,” according to Deployable Energy.

What We Don’t Know

Each of the three demonstrations was an initial, zero-power criticality rather than full-power electricity generation. Deployable Energy’s own roadmap places full-power operation, licensing, and commercialization ahead of the current milestone, according to Deployable Energy. Neither the timeline for those steps nor the reactors’ path to delivering power onto a grid or to end users has been detailed in the criticality announcements.