HWBRIEF
DOE's Nuclear Reactor Pilot Program, created in 2025, aims to get three advanced test reactors to criticality by July 2026, and Oklo's low power Groves unit in Texas is the first on private land.
The US Department of Energy's Nuclear Reactor Pilot Program has logged its first reactor-start milestone against a 4 July 2026 goal of three reactors to criticality.
Oklo brought its Groves test unit in Caldwell County, Texas, to first criticality: the moment a new reactor sustains its first self-sustaining nuclear chain reaction, not a power-generation milestone. Groves is a low-power test reactor, not a commercial power plant, built from a greenfield site on private land, according to the company (Oklo press release).
"Reaching criticality in less than a year is an incredible milestone," said CEO Jacob DeWitte, presenting the timing as company framing rather than independent assessment (Oklo on X).
Antares Nuclear reported a separate advance within a cohort of 11 advanced reactor projects the DOE selected in August 2025, all on private or non-federal land (World Nuclear News). Groves is the fifth pilot reactor to reach criticality, and the first on private land (Power Magazine).
Oklo frames the test platform as preparation for future domestic isotope production, applications that remain planned rather than delivered (Canary Media). What remains open is the cost, schedule, and authorization picture at the other pilot sites.