Oklo Inc. achieved criticality in a test reactor, meeting its early July 2026 target. This milestone demonstrates the reactor's ability to sustain a nuclear fission chain reaction.
The achievement follows the U.S. Department of Energy’s approval of the final safety analysis for the Groves Isotope Test Reactor. This approval transitioned the project into its final pre-startup review phase.
Successful execution of this technical goal represents a significant de-risking event for the pre-revenue company. The milestone marks a critical step toward the commercialization of Oklo's advanced nuclear power plants.