The US Department of Energy (DOE) has cleared Oklo’s Groves Isotope Test Reactor (Groves-1) for unrestricted operations, allowing the facility in Lockhart, Texas, to transition into its research, testing, and training phase. This clearance removes the final operations hold point following the reactor’s first criticality in August 2026.
With unrestricted operations authorised under the DOE Reactor Pilot Program, Oklo will use the 100-watt test reactor to advance several technical and commercial goals. The team will evaluate control rod drive mechanism performance and reliability while conducting criticality and reactivity benchmarking to validate engineering models.
The facility will serve as a qualification platform for nuclear personnel. During recent startups, operators used eye-tracking glasses to gather data aimed at improving control room interfaces for future deployments. Data and operating experience from Groves-1 will directly support the design and operation of Oklo’s planned Aurora powerhouses – commercial fast-fission reactors.
Benchmarking results could also help improve fuel performance and power output across existing small and large light water reactor fleets.
Operating experience from Groves-1 will directly inform the development of Groves-2 Forge, Oklo’s planned isotope production and processing pilot facility selected under DOE’s Nuclear Energy Launch Pad initiative. Groves-2 Forge is designed to combine reactor irradiation with hot-cell processing, covering isotope separation, product recovery, packaging, and transportation. The facility will initially focus on producing lutetium-177, a critical radioactive isotope used in targeted cancer therapies.
“Taking Groves-1 from greenfield to criticality in less than a year was an important demonstration of what our team can accomplish,” said Oklo CEO & co-founder Jacob DeWitte. “Now we’re building on that experience by operating the reactor, testing new capabilities, and learning directly from the work. Those lessons can help us develop the people, systems, and processes needed as we advance additional isotope projects and Aurora powerhouses.”
Oklo was the first to receive a site use permit from the Department of Energy for a commercial advanced fission plant and was awarded fuel from Idaho National Laboratory (INL). It submitted the first custom combined license application for an advanced reactor to the Nuclear Regulatory Commission (NRC). Oklo is also developing advanced fuel recycling technologies in collaboration with DOE and National Laboratories.
DOE has supported Oklo since 2019 through site access, nuclear fuel allocations, safety approvals, and pilot reactor authorisations. This partnership has enabled Oklo to advance its Aurora fast-fission powerhouses, fuel recycling initiatives, and medical isotope reactors. Oklo has received approximately $14.7m in DOE research and development grants, primarily focused on nuclear fuel recycling and waste reduction. Rather than relying on massive federal construction subsidies, Oklo funds its reactor builds primarily through private capital while leveraging the DOE for regulatory pathways, test sites, and physical fuel material.
