Oklo’s Groves-1 to Begin Research and Demonstration Phase after being Cleared by U.S. Department of Energy for Unrestricted Operations

Groves-1’s operating experience will inform the planned Groves-2 Forge isotope production and processing pilot facility.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Groves-1 to transition from reactor deployment demonstration to operating platform for research, testing, and training.

Groves Isotope Test Reactor (Groves-1) was taken critical in August 2026 under the U.S. Department of Energy Reactor Pilot Program, the first to do so under the program on private land.

LOCKHART, Texas--(BUSINESS WIRE)-- Oklo Inc. (NYSE: OKLO) (“Oklo” or “the Company”), an advanced nuclear technology company, today announced the U.S. Department of Energy (DOE) has cleared the final operations hold point for the Groves Isotope Test Reactor (Groves-1), allowing the facility to advance into its research, testing, and training phase. With the facility cleared for unrestricted operations, Oklo will test its capabilities relevant to future isotope reactors and Oklo’s fast fission reactors, the Aurora powerhouse.

Groves Isotope Test Reactor. (Image: Oklo)

Groves-1, under DOE authorization through the DOE Reactor Pilot Program (RPP), reached first criticality at low power less than a year after groundbreaking. The test reactor demonstrated the ability to engineer, construct, authorize, commission, and operate a full nuclear facility. Its next phase will build on this experience to help Oklo prepare the teams and systems needed to support the efficient delivery and operation of additional nuclear projects.

That preparation has already begun. During a recent reactor startup, operators wore eye-tracking glasses to record what they were looking at and for how long, giving the team data to improve the facility’s human-machine interface and inform future design choices. Groves-1 will also serve as a key training and qualification platform for nuclear personnel at future reactor deployments, alongside further equipment testing, including continued evaluations of control rod drive mechanism performance and reliability.

Additionally, Groves-1 will enable criticality and reactivity benchmarking operations that support Oklo’s isotope production capabilities, its engineering and design models, and potentially light water reactors and the large light water reactor fleet. The resulting data could also help improve fuel performance and power output in small and large light water reactors.

“Taking Groves-1 from greenfield to criticality in less than a year was an important demonstration of what our team can accomplish,” said Oklo CEO and co-founder Jacob DeWitte. “Now we're building on that experience by operating the reactor, testing new capabilities, and learning directly from the work. Those lessons can help us develop the people, systems, and processes needed as we advance additional isotope projects and Aurora powerhouses.”

“DOE’s Reactor Pilot Program reset the nuclear industry’s expectations for how quickly we can move from advanced reactor design to demonstration while upholding best-in-class safety standards,” says acting Deputy Assistant Secretary for Nuclear Reactors Chimi Zacot. “Successes like Groves-1's criticality are now paving the way for what comes next.”

Groves-1’s operating experience will directly inform Groves-2 Forge, Oklo’s planned isotope production and processing pilot facility selected under DOE’s Nuclear Energy Launch Pad initiative. Groves-2 Forge will integrate historically fragmented parts of the isotope value chain, combining reactor irradiation with hot-cell processing capabilities. Facility capabilities will include isotope separation, product recovery, packaging, and transportation, with initial focus on lutetium-177, an isotope used in targeted cancer treatments.

About Oklo Inc.: Oklo Inc. is developing fast fission power plants to deliver clean, reliable, affordable energy at global scale; establishing a domestic supply chain for critical isotopes; and advancing nuclear fuel recycling to convert used nuclear fuel into clean energy. Oklo was the first to receive a site use permit from the U.S. Department of Energy for a commercial advanced fission plant, was awarded fuel from Idaho National Laboratory, and submitted the first custom combined license application for an advanced reactor to the U.S. Nuclear Regulatory Commission. Oklo is also developing advanced fuel recycling technologies in collaboration with the U.S. Department of Energy and U.S. National Laboratories.

FORWARD-LOOKING STATEMENTS

This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. These include statements concerning Oklo’s business strategy; the development, licensing, construction, deployment and operation of its powerhouses and fuel fabrication, fuel recycling and radioisotope facilities; anticipated schedules, costs and milestones; commercial and strategic arrangements and their expected benefits; customer demand and market opportunities; and capital requirements and funding. Words such as “expects,” “plans,” “believes,” “targets,” “anticipates,” “may,” “will” and similar expressions identify forward-looking statements, although not all forward-looking statements contain these words.

Forward-looking statements reflect current expectations and assumptions, are not guarantees of future performance, and are subject to risks and uncertainties that could cause actual results to differ materially. Important factors include our ability to complete first-of-a-kind design, testing, construction, commissioning and operations within anticipated costs and schedules; obtain and maintain Department of Energy, Nuclear Regulatory Commission, and other governmental approvals, including those needed to transition from demonstration to commercial operations; secure suitable sites and interconnection and transmission arrangements; obtain high-assay low-enriched uranium, plutonium and other fuels, uranium deconversion and fuel fabrication capacity, specialized components, qualified suppliers and construction services at acceptable costs and within anticipated timelines; satisfy contractual conditions and realize the expected benefits of commercial and strategic arrangements, including through counterparty performance; integrate acquired businesses and realize anticipated benefits; accurately estimate costs, schedules and market demand; obtain additional financing on acceptable terms; and navigate changes in laws, regulations and governmental policies.

Additional information about these and other factors appears in Part I, Item 1A, “Risk Factors,” of our Annual Report on Form 10-K for the year ended December 31, 2025, and in Part I, Item 2, “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” and Part II, Item 1A, “Risk Factors,” of our Quarterly Report on Form 10-Q for the quarter ended September 30, 2026, as updated by subsequent SEC filings. Investors should not place undue reliance on forward-looking statements, which speak only as of the date made. We undertake no obligation to update or revise these statements, except as required by law.

View source version on businesswire.com: https://www.businesswire.com/news/home/20261111613764/en/

Media and Communications for Oklo:
Bonita Chester, Head of Communications and Media at media@oklo.com

Investor Contact:
Sam Doane, Senior Director of Investor Relations at investors@oklo.com

Source: Oklo Inc.

Key Terms

first criticality technical

The moment a nuclear reactor first sustains a controlled, self‑repeating chain reaction during initial startup; it is the key commissioning milestone showing the plant can operate as designed. For investors, first criticality signals that construction and testing reached functional completion, significantly reducing technical and regulatory risk and moving the project closer to generating revenue and qualifying for permits, insurance or financing—much like an engine turning over for the first time after assembly.

control rod drive mechanism technical

A control rod drive mechanism is the mechanical and electrical system that moves a nuclear reactor’s control rods in and out of the core to change the reactor’s fission rate. It converts operator or automatic control signals into precise axial motion—using designs such as electric motors, hydraulic pistons, magnetic jacks or rack-and-pinion gear—so rods can be inserted to reduce reactivity or withdrawn to increase it; the drives also provide rapid insertion capability for automatic shutdowns (scrams) and include position feedback and locking or braking features to hold rod position under normal and fault conditions.

hot-cell processing technical

Hot-cell processing is the manufacture, handling or testing of radioactive materials inside heavily shielded, remote-operated enclosures called hot cells. Operators use gloves, robotic manipulators, or automated systems through thick shielding and filtered ventilation to perform synthesis, purification, dispensing and waste containment while preventing radiation exposure; the work requires specialized equipment, radiation safety controls and regulatory licensing.

lutetium-177 medical

Lutetium-177 is a radioactive form of the element lutetium used as a therapeutic agent in medicine to deliver targeted radiation to cancer cells. Think of it as a microscopic guided missile that carries radiation directly to tumors while limiting damage to healthy tissue; because its use depends on manufacturing capacity, regulatory approvals, clinical trial results and hospital adoption, changes in supply, safety data or approval status can materially affect the value and outlook for companies that make, supply or use these therapies.