US test reactor cleared for operations

Oklo’s Groves Isotope Test Reactor, or Groves-1, near Lockhart, Texas, has received US Department of Energy clearance for unrestricted operations. The reactor reached first criticality in August, less than a year after construction began, as part of the DOE’s Reactor Pilot Program for accelerating advanced-reactor demonstrations. The clearance releases its final operational hold point and lets Oklo begin research, testing, and workforce training. The company says the experience will inform Groves-2 Forge, a planned isotope-production and processing pilot facility, as well as development of its Aurora fast-fission power reactor.

Groves-1 will be used to qualify personnel for future deployments and evaluate equipment, including the performance and reliability of control-rod drive mechanisms. Its experiments will also produce data on criticality and reactivity to support isotope production, engineering models, and potentially improvements to fuel performance and output in light-water reactors. The DOE pathway authorizes prototypes for research, development, and demonstration under its authority in the Atomic Energy Act; commercial reactor designs still require Nuclear Regulatory Commission review and approval. A recently finalized NRC rule allows commercial licence applicants to submit relevant evidence from DOE or Department of War demonstration programmes, while the NRC independently assesses safety. This framework aims to build on prototype testing and make commercial licensing reviews more efficient.