Oklo Targets First Criticality for Texas Reactor

Oklo advanced its Groves Isotope Test Reactor in Lockhart, Texas, after the U.S. Department of Energy approved the facility’s Documented Safety Analysis under DOE’s Reactor Pilot Program. The approval moves Groves into DOE’s final pre-startup review phase and positions the privately developed test reactor for fuel loading, startup testing, and first criticality.

The DSA approval follows DOE’s earlier approval of the Preliminary Documented Safety Analysis. Together, the two approvals establish the facility’s safety basis, including hazard analysis, safety controls, and operating requirements. Oklo said Groves now awaits DOE readiness review and startup approval before the facility can receive and load nuclear fuel.

Groves supports Oklo’s isotope business, with a focus on domestic production of critical isotopes used in cancer diagnosis and treatment, advanced manufacturing, scientific research, space exploration, and national security. Oklo said the pilot facility will help validate operating procedures, reactor performance, and production processes before commercial-scale isotope production.

• Facility: Groves Isotope Test Reactor

• Location: Lockhart, Texas

• Program: DOE Reactor Pilot Program

• Milestone: Documented Safety Analysis approved

• Next steps: DOE readiness review, startup approval, fuel loading, startup testing, first criticality

• Target: First criticality in July 2026

• Purpose: Domestic isotope production and reactor operating validation

“When the Administration issued its Executive Order calling for multiple advanced reactors to go critical outside the national laboratories, it challenged the industry to demonstrate a new way forward,” said Oklo co-founder and CEO Jacob DeWitte. “Groves is that demonstration.”

🌐 Analysis: Oklo’s Groves milestone arrives as the company builds a broader commercial position around advanced nuclear power for AI-era infrastructure. Meta and Oklo announced a January 2026 agreement supporting a planned 1.2 GW nuclear energy campus in Pike County, Ohio, to serve Meta’s regional data center needs, while Oklo also signed a non-binding master power agreement with Switch in 2024 targeting up to 12 GW of Aurora powerhouse deployments for AI, cloud, and enterprise data centers.  

Meta’s nuclear strategy now spans Oklo, TerraPower, Vistra, and Constellation, reflecting a broader hyperscale move to secure firm, long-duration power for AI data center growth. The key distinction for Oklo remains execution: Groves supports isotope production rather than data center power directly, but its safety-review progress could strengthen confidence in Oklo’s ability to move advanced reactor projects through real-world permitting, construction, and startup processes.