DOE Confirms Third Microreactor Criticality Under Executive Order 14301 Programs by July 2026

The Department of Energy authorized initial criticality for Antares Nuclear’s sodium heat-pipe reactor in early June, Valar Atomics’ gas-cooled unit later that month, and Deployable Energy’s Unity design on 30 June. Each test occurred inside existing DOE facilities under the Reactor Pilot Program and its successor Nuclear Energy Launch Pad, bypassing standard NRC licensing timelines for first-of-a-kind units.

Executive Order 14301 directed the DOE to compress reactor testing cycles and pair them with a parallel Fuel Line Pilot Program. The order’s text specifies performance metrics for rapid iteration rather than prescriptive design approvals. Eleven projects were selected; three have now met the criticality threshold, demonstrating that private capital can be aligned with federal site access to shorten development loops.

The sequence advances US interests in domestic fuel-cycle control and grid resilience. It reduces exposure to Russian and Chinese enrichment capacity while creating a test-bed data advantage for US vendors. Costs include accelerated wear on national-lab infrastructure and potential future regulatory friction when designs transition to commercial NRC review.

Remaining Reactor Pilot Program participants, including Oklo and Radiant, continue zero-power testing. Full-power heat demonstrations and fuel qualification under the Fuel Line Pilot Program are scheduled through 2027, determining which designs reach grid deployment before the next licensing cycle.