U.S. DOE Moves Cold War Plutonium Toward Advanced Reactor Fuel

The United States retains about 95 metric tons of weapons-grade plutonium from dismantled Cold War warheads. A 2019 watchdog estimated burying it would cost $19 billion, prompting a search for alternative uses.

DOE advances talks to fuel advanced nuclear reactors with old plutonium

In 2025 the DOE launched the Surplus Plutonium Utilization Program to turn up to 20 metric tons of weapons-grade plutonium into fuel for advanced reactors, including small modular and fast-reactor designs, shifting processing to private firms.

DOE advances talks to fuel advanced nuclear reactors with old plutoniumCold war-era plutonium deal: Oklo selected for advanced reactor fuel talks

The DOE’s Office of Nuclear Energy runs the program. Ted Garrish called the material “an immense, untapped energy resource.” Five firms—Oklo, Exodys Energy, SHINE Technologies, Standard Nuclear and Flibe Energy—are invited. Oklo pledged $2 billion for fuel-fabrication infrastructure, a $1.2 billion Meta partnership, and its stock rose 12 %.

Cold war-era plutonium deal: Oklo selected for advanced reactor fuel talks

DOE spokespersons said the plan will “unlock the next level of private funding to broaden domestic nuclear fuel supplies, spur innovation on American recycling technologies, and fuel the nation’s nuclear renaissance.” It requires “understanding of the technology, security plans, and regulatory compliance.” NTI Vice President Scott Roecker warned that giving weapons-grade plutonium to private firms raises proliferation risk. NYU professor Daniel Speyer said purified plutonium could make bomb construction “almost a trivial act.” Former Energy Secretary Ernest Moniz warned of a poor track record for plutonium-based fuels.

Scientific AmericanDOE advances talks to fuel advanced nuclear reactors with old plutoniumGizmodo

DOE lists Oklo, Exodys Energy, SHINE Technologies, Standard Nuclear and Flibe Energy as the five selected firms. Other sources name Oklo, Terrestrial Energy, TRISO-X and Valar Atomics, indicating a roster discrepancy. The plutonium amount is described as “up to 20 metric tons” in some accounts and “approximately 20 metric tons” in others. No source gives a firm NRC licensing schedule or detailed IAEA safeguard plan.

Cold war-era plutonium deal: Oklo selected for advanced reactor fuel talks

• “The most difficult step in getting a nuclear weapon is having enough of that material,” — Scott Roecker, Vice President, Nuclear Threat Initiative

Scientific American

• “It’s not something that a small organization really probably could do, but if you give them plutonium in purer form, I think it’s almost a trivial act to make a bomb,” — Daniel Speyer, Professor, New York University

Scientific American

• “Fuel supply constraints are a key throttle to advanced reactor development,” — Jacob DeWitte, Co-founder and CEO, Oklo

DOE advances talks to fuel advanced nuclear reactors with old plutonium

• “The transfer of weapons-usable plutonium to private industry would increase the risk of nuclear weapons proliferation, including to rogue states or terrorists,” — Senator Edward Markey, Letter to the President

Scientific American

Turning surplus weapons-grade plutonium into reactor fuel could avoid the $19 billion burial cost, provide a domestic source for next-generation reactors, and ease uranium supply gaps as Russian imports end in 2028. Critics warn it may lower barriers to nuclear proliferation and raise the cost and complexity of advanced reactor rollout.

DOE advances talks to fuel advanced nuclear reactors with old plutoniumScientific AmericanCold war-era plutonium deal: Oklo selected for advanced reactor fuel talks

Oklo and the other firms aim to secure plutonium allocations and start fuel-fabrication trials in 2027. Demonstration reactors could receive the fuel by 2028, with commercial deployment targeted for 2029-2030, pending NRC certification and IAEA safeguard verification.

Cold war-era plutonium deal: Oklo selected for advanced reactor fuel talks