The U.S. Department of Energy has cleared the final operations hold point for Oklo's Groves Isotope Test Reactor, known as Groves-1, near Lockhart in Caldwell County, Texas, according to a November 12 report from World Nuclear News. The decision allows the reactor to move into its research, testing, and training phase.

Groves-1 reached first criticality in August 2026, less than a year after groundbreaking. It is one of 11 advanced reactor projects the DOE selected in August 2025 for its Nuclear Reactor Pilot Program. Executive orders issued in May 2025 called for at least three prototype reactors to reach criticality by July 4, 2026, and the DOE streamlined its authorization pathway in response.

Oklo plans to use Groves-1 to test capabilities for isotope reactors and for its Aurora fast fission reactor. Planned work includes training personnel, evaluating control rod drive mechanism performance, and running criticality and reactivity benchmarking. According to the report, the data could also inform light water reactor fuel performance and power output.

Operating experience from Groves-1 will feed into Groves-2 Forge, a planned isotope production and processing pilot facility under the DOE's Nuclear Energy Launch Pad initiative. The milestone also connects to commercial licensing. In October, the Nuclear Regulatory Commission finalized a rule allowing applicants to use DOE or Department of War reactor demonstration data in commercial license applications, giving projects authorized under the DOE pathway a route toward NRC review.

Chimi Zacot, the DOE's Acting Deputy Assistant Secretary for Nuclear Reactors, said, "Successes like Groves-1's criticality are now paving the way for what comes next."

Source: World Nuclear News - https://www.world-nuclear-news.org/articles/us-test-reactor-cleared-for-operations