Advanced nuclear startup Oklo achieved first criticality at its Groves Isotope Test Reactor in Texas in less than 12 months.
- Oklo achieved a self-sustaining nuclear chain reaction at its Texas facility within a single year, moving from a greenfield plot to an operational reactor.
- The milestone was reached under the U.S. Department of Energy’s Reactor Pilot Program.
- Designed to lay the foundation for future radioisotope production for healthcare and industry, the development sent Oklo shares up 4.3% in pre-market trading.
Advanced nuclear technology developer Oklo Inc. said on Thursday that its Groves Isotope Test Reactor has reached “criticality,” achieving a self-sustaining low-power chain reaction less than a year after breaking ground.
The landmark achievement in Central Texas marks the first time a reactor developed under the U.S. Department of Energy’s Reactor Pilot Program has reached criticality on private land from a greenfield construction site.
The momentum comes as the White House pushes for an aggressive expansion of domestic nuclear infrastructure to support rising electricity demand from data centers and high-tech manufacturing. Recent executive mandates set targets to quadruple U.S. nuclear power generation capacity.
Following the announcement, shares of Oklo (OKLO) rose 4.3% to $44.86 in New York pre-market trading but slipped 0.9% in afternoon trading.
Nuclear Development Timelines Shorten
Reaching criticality is an operational threshold where nuclear fission produces a continuous, steady release of energy.
“Reaching criticality in less than a year is an incredible milestone for our team,” said Jacob DeWitte, co-founder and chief executive officer of Oklo. “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.”
The rapid buildout was made possible by the Energy Department’s pilot framework, which allowed engineering, construction, and commissioning steps to move forward in tandem with regulatory safety assessments.
Fueling Medicine, Industry, And Tech
While traditional commercial power generation remains a broader target, the Groves facility serves as a low-power testing ground and operational foundation for Oklo Isotopes. The division intends to supply key radioisotopes across medical, industrial, research, space, and defense sectors.
State leaders praised the project for strengthening domestic supply chains and boosting specialized manufacturing. Texas Governor Greg Abbott noted that the achievement reinforces the state’s positioning at the forefront of advanced energy expansion and medical isotope manufacturing.
Oklo’s reactor is the fifth small modular design to hit criticality through the DOE’s pilot program, joining experimental designs by companies such as Aalo Atomics, Deployable Energy, Antares Nuclear Inc., and Valar Atomics Inc.
OKLO Stock: Retail View
Retail sentiment on Stocktwits was ‘neutral’ with ‘low’ message volumes. Retail chatter on the stock has jumped about 130% from the previous session and 80% over the past 30 days.
OKLO stock has lost 43% year-to-date.
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