Two nuclear startups, Oklo and newcleo, have struck a partnership to explore turning Cold War-era plutonium into fuel for next-generation reactors. The deal aims to repurpose material once stockpiled for nuclear weapons — a move that could solve two problems at once: disposing of surplus plutonium and providing a low-carbon energy source.
What the Plutonium Is
The plutonium in question comes from dismantled warheads and other military stockpiles left over from the Cold War. Both the United States and Russia have large quantities of the material, much of it stored under international safeguards. Using it as reactor fuel would reduce the need to mine fresh uranium and could help shrink the inventories that governments have struggled to secure or dispose of.
The Companies Involved
Oklo, based in California, is developing a small, liquid-metal-cooled fast reactor designed to run on used nuclear fuel or surplus plutonium. Newcleo, a London-headquartered startup, is working on a lead-cooled fast reactor that can also consume plutonium as fuel. The two companies said they will combine technical expertise to find a safe, efficient way to fabricate fuel from the Cold War material. Neither firm gave a timeline for when such fuel might be commercially available.
Regulatory and Safety Hurdles
Moving plutonium from weapons stockpiles to civilian reactors faces serious hurdles. The U.S. Department of Energy and the International Atomic Energy Agency would need to approve any transfer and processing. Nonproliferation advocates have long warned that plutonium in any form is a proliferation risk. Both Oklo and newcleo say their reactors are designed to burn plutonium completely, leaving less waste that could be diverted. Still, critics are likely to ask whether the security chain from warhead to reactor can remain airtight.
What Happens Next
The partnership is in an early exploration phase. Oklo and newcleo plan to submit a joint feasibility study to regulators by 2026. Whether they can win public and political support for using weapons-grade plutonium as fuel remains an open question.
