LOCKHART, Texas – (Our Texas Times) – Oklo Inc. has made a breakthrough at its Groves Isotope Test Reactor in Lockhart, conducting the first controlled self-sustaining nuclear chain reaction within less than a year since the start of construction of the experimental facility. The Aug. 6 announcement marked the criticality of the reactor and advanced Oklo Inc.’s plans to create a national production of special isotopes for various purposes, including medicine, industrial needs, research, space and national security.
The Groves reactor is a low-power experimental reactor of the Proto-Town project implemented in Caldwell County, Texas. As stated by the U.S. Department of Energy, the reactor is designed to work with thermal power up to 100 watts. That means that the project mainly focuses on the test, training, and isotope production rather than electricity generation.
Criticality implies that the reactor established controlled nuclear fission chain reaction capable of maintaining itself. Criticality is an essential step on the way to commissioning the nuclear reactor and allows for collecting information about the reactor behavior, operational procedures, and other details.
According to the Department of Energy, the Groves experiment achieved the criticality at Oklo’s Lockhart-area facility on the night of Aug. 5. The Department of Energy also noted that the Groves is the fifth DOE-authorized advanced reactor to achieve criticality in summer of 2026.
The Project Realized Within the New Federal Program for Reactors
The Groves project was realized within the Reactor Pilot Program of the U.S. Department of Energy, which was launched in 2025 to accelerate the test of advanced reactor technologies outside traditional sites of national laboratories.
As announced by DOE in June 2025 in connection with the Executive Order 14301, 11 advanced reactor projects were selected by DOE in August. The goal of the program is to provide an alternative to the qualification of experimental reactors through DOE while preparing technologies for commercial licensing.
In contrast to the long-term development required for many commercial nuclear reactors projects, the pilot program allows for simultaneous engineering, construction, and operational preparation and federal safety evaluation.
According to Oklo, the Groves project was built on the greenfield site on private property. The company managed or procured construction, equipment, fuel, and operation programs. Oklo treats the short construction-to-criticality timeline as an important test of the opportunity to deploy small advanced reactors faster.
The federal approval process for the project went through several milestones in 2026. First of all, the Nuclear Safety Design Agreement for the Groves was approved by DOE in March. Then, on July 1, the Documented Safety Analysis was approved, taking the project closer to the final pre-startup review. Then, on July 23, Oklo announced the start-up authorization, allowing for loading of the fuel, start-up tests, and achieving the criticality. The latter was successfully conducted around two weeks later.
Focus on the Production of Medical and Industrial Isotopes
The Lockhart project is a part of Oklo’s plan to boost the domestic production of radioisotopes – materials used in cancer diagnosis and treatment, semiconductor production, scientific research, and space missions.
According to Oklo, its isotope program includes the construction of purpose-built reactors, processing of the existing radioactive materials and, finally, recovery of valuable isotopes through advanced nuclear fuel recycling.
The Groves reactor will be used for obtaining the operating experience and data that may be applied in future commercial isotope-production facilities. That will include the experience in engineering, procurement, construction, reactor start-up, operator training, safety programs, and qualification procedures.
As stated in DOE documents, Groves is a zero-power critical assembly regardless of its thermal capacity. According to the department, the project is aimed at the demonstration of the capability of Oklo to safely design and construct such facilities and obtain the experience in building future reactors capable of producing more than 40 kinds of valuable radioisotopes.
Oklo’s Plans in Texas Viz-a-Viz Its Isotopes
Oklo’s Texas plans imply that the Groves project is one of the first demonstrations and not the final commercial facility. According to the company, the experience that Oklo will obtain from the reactor will allow for boosting the isotope production during the rest of the decade.
Acquisition of Atomic Alchemy and Oklo’s Isotope Program
The isotope business of Oklo Inc. became much larger thanks to the acquisition of Atomic Alchemy, which specializes in radioisotope production.
Initially, in May 2024, the companies announced the partnership. Then, later in 2024, Oklo Inc. proposed an acquisition of Atomic Alchemy. The acquisition was completed by the end of February 2025 in an all-stock deal evaluated at approximately $25 million. Thus, Atomic Alchemy became a subsidiary of Oklo Inc.
Thanks to this acquisition, Oklo obtained a second business line beside its plans to develop advanced nuclear power plants.
The company develops its Aurora Powerhouse, which is a fast-fission reactor platform designed for providing electricity and heat to customers such as data centers, industrial facilities, defense installations and communities. The current designs of the Aurora Powerhouses are intended for up to 75 MW of electric output.
Oklo Inc. Has Long Experience in Nuclear Development
Oklo Inc. has been developing advanced reactors for more than a decade and has been cooperating with the Nuclear Regulatory Commission since 2016.
Thus, in 2019, the company received the site use permit from DOE for its proposed Aurora reactor at Idaho National Laboratory and received the access to the high-assay low-enriched uranium material for the fuel of the reactor.
The regulatory history of the company also included some setbacks. So, Oklo submitted the custom combined license application for its proposed Aurora reactor to the NRC in 2020. However, in January 2022, NRC denied the application without prejudice, stating that additional information was necessary on several issues. Denial without prejudice means that the company has an opportunity to submit the application again in the future.
Oklo continues working with the federal regulators while developing new licensing strategies and technical documentation.
Besides, Oklo Inc. entered the public market in May 2024 as a result of completion of its business combination with AltC Acquisition Corp. The shares of Oklo started trading on New York Stock Exchange under the ticker symbol OKLO.
Texas Creates Place for the Development of Advanced Nuclear Technologies
The Groves project is one more element of the already extensive energy industry of Texas, where the state authorities try to attract investments into the development of advanced nuclear technologies, fuel production, and special nuclear materials.
For Oklo, the immediate importance of Groves is not in the amount of power generated by the reactor but in the demonstration of the opportunity to construct and launch a new reactor rather fast.
Moreover, the Lockhart-area facility will give Oklo Inc. the operating experience, which can be applied to larger isotope-production projects and its planned commercial power reactors.
The Groves reactor is expected to stay experimental. As indicated in the DOE’s environmental review, the operational phase of the reactor is planned till the end of 2026, when the reactor will serve as the testbed for technologies and procedures, which may be applied to the future commercial facilities.
