DOE Approves First Private Reactor Criticality Outside Labs, Shifting U.S. Nuclear Policy

Executive Order 14301 (May 2025) directed the DOE to approve at least three advanced test reactors for zero-power criticality by July 4 2026, using a DOE-only process that bypasses the NRC. The Nuclear Energy Launch Pad, launched March 2026, created a “Launch Pad USA” pathway for projects on federal or private land.

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On June 18, Valar Atomics’ Ward 250 micro-reactor achieved self-sustaining criticality at the Utah San Rafael Energy Lab near Orangeville, Emery County. The high-temperature gas-cooled unit uses TRISO-fueled HALEU and is rated for 100 kW thermal; it operated at 10 kW by June 22. DOE confirmed the event the same afternoon, marking the first DOE-authorized criticality outside a national laboratory.

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Key milestones: Antares Nuclear’s Mark-0 went critical at Idaho National Laboratory on June 4; Valar’s Ward 250 did so in Utah on June 18; Deployable Energy’s Unity achieved zero-power criticality at INL on June 30; DOE announced on July 1 that three distinct micro-reactor designs had reached criticality in one month, meeting the July 4 deadline; Aalo Atomics is preparing Project First Light for criticality and Oklo secured DOE safety-analysis approval for its Groves Isotope Test Reactor in Texas.

Power MagazineAmerica just flew a nuclear reactor to Utah on an Air Force C-17 cargo plane, the first reactor the military has ever airlifted, set it down in a coal town, and brought it critical, a helium-cooled maOklo (OKLO) Stock Surges 5% Following DOE Safety Approval for Texas Nuclear Reactor

Three reactors—Antares Mark-0 (85 kW), Valar Ward 250 (100 kW thermal, 5 MWe target), and Deployable Unity (1 MWe)—reached criticality in June 2026, a world first. The DOE deadline remains July 4 2026 for at least three reactors to meet the milestone.

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Energy Secretary Chris Wright described the Utah flight and criticality test as a historic moment for America’s nuclear renaissance. DOE framed the milestones as fulfillment of a precedent-setting directive to reignite nuclear energy innovation in the United States. DOE officials Dr. Rian Bahran and Bob Boston praised INL staff and “champions” for rapid approvals.

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All three reactors remain low-power test units; Ward 250’s 100 kW output is far below grid scale, and its 5 MWe goal still requires full-scale construction, while reliance on HALEU and TRISO fuels draws industry scrutiny.

America just flew a nuclear reactor to Utah on an Air Force C-17 cargo plane, the first reactor the military has ever airlifted, set it down in a coal town, and brought it critical, a helium-cooled ma

• “another historic moment for America’s nuclear renaissance” — Chris Wright, U.S. Energy Secretary

America just flew a nuclear reactor to Utah on an Air Force C-17 cargo plane, the first reactor the military has ever airlifted, set it down in a coal town, and brought it critical, a helium-cooled ma

• “this reactor was built to make power.” — Isaiah Taylor, founder and CEO, Valar Atomics

America just flew a nuclear reactor to Utah on an Air Force C-17 cargo plane, the first reactor the military has ever airlifted, set it down in a coal town, and brought it critical, a helium-cooled ma

• “Let’s use what’s readily available,” — Sanjay Mukhi, co-founder and chief commercial officer, Deployable Energy

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• “With approval of both the Preliminary and Documented Safety Analyses, Groves now moves into the final phase before startup, including readiness review, fuel loading, and criticality,” — Jacob DeWitte, co-founder and CEO, Oklo

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Valar plans to scale Ward 250 to a 5 MWe commercial unit and cluster reactors into “gigasites” for industrial heat and AI data centers. Deployable Energy targets factory-built Unity units shipped in 20-foot containers by 2028. Aalo Atomics expects Project First Light to achieve criticality before July 4, and Oklo aims for Groves criticality in July 2026, with its Aurora fast-reactor slated for commercial operation in 2028.

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