Oklo selected for US surplus plutonium programme

The Department of Energy (DOE) announced plans in October last year for private companies to dispose of about 20 tonnes of surplus plutonium by making the materials available for advanced nuclear technologies. A Surplus Plutonium Utilization Program request for applications issued on 21 October describes the plutonium on offer, and the "thresholds" prospective applicants must meet. The DOE wants applications "with detailed recycling and processing plans, including funding commitments and schedule to utilise the surplus plutonium materials within DOE's inventories for nuclear fuel for reactors in the United States". Applications were due by 21 November.

Oklo said its selection - alongside four other advanced nuclear companies (Exodys Energy, SHINE Technologies, Standard Nuclear, and Flibe Energy) - supports the company's broader fuel strategy, which includes multiple pathways to source fuel to support advanced reactor deployment while domestic enrichment and fuel infrastructure continue to scale.

SHINE Technologies CEO, Greg Piefer, said: "We've spent more than a decade building the capabilities needed to handle complex nuclear materials - recycling used fuel, recovering isotopes, doing the kind of separations work this programme calls for. Turning surplus material that's been sitting in storage into fuel for the next generation of reactors is exactly the kind of problem we built SHINE to solve."

In partnership with France-headquartered innovative reactor developer Newcleo, Oklo would lead the utilisation of surplus plutonium, while Newcleo would bring relevant fuel experience and potential project capital, subject to definitive agreements, customary approvals, and applicable US security and safeguards requirements.

"Oklo and Newcleo view the programme as a pathway for disposition through use: converting material that already exists into fuel for advanced reactors, using it to generate reliable electricity, and consuming it through fission under stringent security, safeguards, and material control requirements," the companies said in a joint statement. "In doing so, the programme can turn a long-term material management challenge into a domestic energy source."

"Fuel supply constraints are a key throttle to advanced reactor development," said Oklo co-founder and CEO Jacob DeWitte. "This programme creates a pathway to use existing surplus material as bridge fuel for advanced reactors to bring more reactors online sooner. Material that has been set aside for disposal can instead be converted into fuel to produce electricity through fission."

Newcleo CEO and founder Stefano Buono added: "We are proud of this transatlantic partnership with Oklo to deliver on our promise of reducing nuclear liabilities through our fuel and reactor technologies. The US is taking a visionary approach to the fuel cycle, and we look forward to contributing to it."

In October 2025, Newcleo and Oklo signed an agreement to develop advanced fuel fabrication and manufacturing infrastructure in the USA. At the time, Newcleo said it was planning to invest up to USD2 billion "via an affiliated investment vehicle", with the investment spanning "multiple projects under US oversight" and aiming to "foster transatlantic cooperation that enhances energy security, and focus on creating a robust and resilient fuel ecosystem. Specific projects and investment amounts will be detailed in forthcoming definitive agreements".

In March this year, Newcleo announced it had initiated pre‑application engagement with the US Nuclear Regulatory Commission to support the future licensing of its first Lead-cooled Fast Reactor and an associated mixed‑oxide (MOX) fuel fabrication facility in the USA.

Newcleo is developing its Small Modular Lead-cooled Fast Reactor (SM-LFR) technology. According to the company's delivery roadmap, the first non-nuclear precursor prototype of its reactor is expected to be ready by later this year in Italy, the first reactor operational in France by the end of 2031, while the final investment decision for the first commercial power plant is expected around 2029. Newcleo plans to directly invest in a MOX plant to fuel its small modular lead-cooled fast reactors.

Oklo's Aurora powerhouse is a fast neutron reactor that uses heat pipes to transport heat from the reactor core to a supercritical carbon dioxide power conversion system to generate electricity. Building on the design and operating heritage of the Experimental Breeder Reactor II (EBR-II), which ran in Idaho from 1964 to 1994, it uses metallic fuel to produce electricity and usable heat, and can operate on fuel made from fresh HALEU or used nuclear fuel.