goingcritical:natura-msr-1United States · Research reactor

Natura MSR-1

Status: Site preparation target criticality 2026 (confidence: low) ? 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. Operating 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.

Developer: Natura Resources

Site: Science & Engineering Research Center, Abilene Christian University, Abilene, Texas

MesaBirminghamCiudad JuarezFt. WorthAustinSan AntonioMemphis

Company stated (Dec 2025, on signing its DOE OTA) that it is advancing MSR-1 toward criticality in 2026; host facility complete and reactor procurement underway, but not achieved by the July 4, 2026 program deadline

Details

Design	MSR-1 — 1-MWt liquid-fueled molten salt research reactor (HALEU fuel, FLiBe coolant)
Capacity	Undisclosed

Milestone history

1. Announced August 12, 2025
2. Construction start —
3. Fuel load —
4. First criticality target 2026