US Nuclear Startup Oklo Achieves First Criticality at Texas Reactor in Under a Year

en.Wedoany.com Reported - Oklo, an advanced nuclear technology company headquartered in California, has achieved first criticality at its Groves Isotope Test Reactor in Texas, less than a year after the project broke ground. The low-power reactor was built under the US Department of Energy's (DOE) Reactor Pilot Program and is the first reactor under the program to reach criticality on private land.

First criticality means the reactor has established a controlled and self-sustaining nuclear chain reaction. Groves is a test facility rather than a commercial power reactor, providing Oklo with an operational platform to advance its isotope production business. The reactor was built from a greenfield site, with Oklo handling engineering, construction, procurement, operational planning, and startup preparation, while components such as fuel were produced in-house or procured commercially. Groves is part of Oklo Isotopes' domestic isotope production program, with applications spanning healthcare, industry, research, space, and national security.

Oklo stated that the Reactor Pilot Program enabled design, construction, regulatory, and commissioning efforts to proceed in parallel with DOE's safety review and authorization, allowing the project to move from greenfield to startup in months rather than years. Jacob DeWitte, co-founder and CEO of the company, said that reaching criticality in less than a year is a significant milestone for the team, noting that Oklo independently completed earthwork, facility construction, component manufacturing or procurement, and operational planning. The company said the process also established procedures for reactor operations, commissioning, safety preparedness, and staff training, setting a new reference benchmark for the Reactor Pilot Program and laying the groundwork for future large-scale advanced nuclear deployment.

The DOE established the Reactor Pilot Program to provide selected reactor projects with a faster development and licensing pathway. Groves offers a real-world test case for this pathway, though timelines for future commercial reactors will still vary based on design, licensing, and construction requirements. Groves' current significance lies in isotopes rather than power generation. Oklo Isotopes plans to apply lessons learned from the test reactor to build radiomaterial production capabilities, with isotope applications including diagnostic imaging, cancer treatment, industrial testing, scientific research, space applications, and national security.

Ted Garrish, Assistant Secretary for Nuclear Energy, said that thanks to President Trump's directive to create the Reactor Pilot Program, Oklo's Groves project is part of the revitalization of America's nuclear energy industry, and he recognized the work of Oklo, DOE, and Idaho National Laboratory staff. Oklo is also developing fast fission power plants, nuclear fuel recycling technologies, and domestic supply chains for critical isotopes. The company said the Groves project will subsequently reduce uncertainty and execution risk in these efforts.

First criticality at Groves does not mean Oklo has completed commercial isotope deployment, but it establishes an operational foundation for the company to continue testing, accumulate operational experience, and develop future isotope production facilities.