Oklo's Groves Reactor Achieves Criticality as Fifth DOE-Authorized Advanced Reactor

Oklo's Groves Isotope Test Reactor achieved criticality at the company's Lockhart, Texas, facility, becoming the fifth U.S. Department of Energy (DOE)-authorized advanced reactor to do so this summer. The milestone is part of the DOE Reactor Pilot Program, which was created to accelerate demonstration of next-generation nuclear technologies.

Assistant Secretary for Nuclear Energy Ted Garrish praised the achievement, noting, "Thanks to President Trump's precedent-setting directive to create the Reactor Pilot Program, Oklo's Groves Isotope Test Reactor is part of the revival of America's nuclear energy industry. We applaud the work of the Oklo, DOE, and Idaho National Laboratory staff who helped achieve this milestone."

Oklo co-founder and CEO Jacob DeWitte said, "Reaching criticality in less than a year is an incredible milestone for our team. Oklo developed Groves from a greenfield site on private land, completed full-scale civil excavation and construction, manufactured or commercially procured all components, including fuel, and developed its operating programs in-house. Taken together, we believe these accomplishments establish a new benchmark for the Reactor Pilot Program and set the stage for the future of advanced nuclear deployment at scale."

The Groves achievement joins similar milestones by Antares Nuclear, Valar Atomics, Deployable Energy and Aalo Atomics, all of which have moved from design to demonstration under DOE authorization. DOE's new authorization pathway is presented as a model for regulatory reform that can accelerate innovation and support President Trump's Energy Dominance agenda.

According to the release, the Groves test reactor will inform a future commercial variant intended to produce isotopes for medicine, advanced manufacturing, scientific research, space exploration and national security needs, underscoring the broader strategic goals of the Nuclear Energy Launch Pad.