goingcritical:deployable-unityUnited States · Microreactor
Deployable Energy Unity
Status: Critical since July 1, 2026 Reactor status full glossary → Announced Publicly announced — a site and design are proposed, but construction has not begun. Site preparation Early site and civil works are under way; the first safety-related ("nuclear") concrete has not yet been poured. Under construction Formal construction has begun, marked by the first nuclear concrete. Fuel loaded Nuclear fuel has been loaded into the core. The reactor is fuelled but has not yet gone critical. Critical Has reached first criticality — a self-sustaining chain reaction, usually at low power — but is not yet connected to the grid. Grid connected Synchronised to the electrical grid and exporting power for the first time, but still in commissioning and power-ascension testing — not yet in commercial service. In commercial operation — the operator has formally declared the unit in regular commercial service. Shut down Permanently shut down and no longer generating; may be defuelled, undergoing decommissioning, or preserved in place. Canceled Abandoned before completion.
Site: National Reactor Innovation Center, Idaho National Laboratory, Idaho
Third DOE-authorized criticality under EO 14301; selected under the Nuclear Energy Launch Pad (successor/expansion of the Reactor Pilot Program), not among the original 11 pilot projects; ~150 days from project kick-off to zero-power fueled criticality (DOE announcement implies late June 30)
Details
| Design | Unity Nuclear Battery — helium-cooled, LEU UO2-fueled high-temperature gas microreactor (1 MWe class, containerized) |
| Capacity | 1 MW (thermal where reported) |
Milestone history
- Announced April 27, 2026
- Construction start —
- Fuel load —
- First criticality July 1, 2026
References
- DOE, third advanced reactor criticality (announced July 1, 2026)
- ANS Nuclear Newswire, Deployable Energy achieves criticality at INL (July 1, 2026)
- World Nuclear News, criticality for third US reactor ahead of 4 July deadline
- POWER Magazine, first four Nuclear Energy Launch Pad selections (April 27, 2026)