US Turns Cold War Plutonium Into Nuclear Fuel in Push for Advanced Reactors

The United States is moving to repurpose surplus Cold War-era plutonium into fuel for next-generation nuclear reactors, selecting five companies for advanced negotiations in a program aimed at transforming former weapons material into a future energy source.

The initiative marks a major shift in US nuclear policy, as the administration seeks to redirect plutonium previously designated for long-term disposal toward commercial electricity generation and advanced reactor development.

Among the companies selected is Oklo, whose shares rose more than 5.5% to $69.51 following the announcement. The company said it plans to collaborate with European reactor developer Newcleo on developing nuclear fuel derived from surplus plutonium.

The US Department of Energy said the other companies entering negotiations include Exodus Energy, Shine Technologies, Standard Nuclear, and Valar Atomics, all privately held firms focused on advanced nuclear technologies.

The effort follows plans first reported last year indicating that the Trump administration intended to make roughly 20 metric tons of plutonium, extracted from dismantled nuclear warheads, available to American energy companies.

President Donald Trump ordered a halt in May to large parts of the government’s plutonium disposal program, instead directing officials to explore its use as fuel for advanced nuclear systems.

The US Department of Energy currently stores excess plutonium in heavily secured weapons facilities in states including South Carolina, Texas, and New Mexico. The radioactive material has a half-life of approximately 24,000 years and requires highly specialized protective handling.

Oklo said Newcleo would contribute technical expertise in nuclear fuel development and potentially provide capital support for the project, subject to regulatory approvals and US national security safeguards.

“This program creates an opportunity to use surplus materials as transitional fuel for advanced reactors, accelerating reactor deployment,” said Jacob DeWitte, Oklo’s co-founder and chief executive. “Material once intended for disposal can instead be converted into fuel for electricity generation.”

Supporters of the initiative argue that reusing plutonium could strengthen America’s advanced nuclear sector, reduce waste-management burdens, and help secure private investment in emerging reactor technologies.

But the plan has also triggered concerns over nuclear proliferation and security risks.

Democratic lawmakers have urged the administration to abandon the proposal, warning that the quantity of plutonium involved could theoretically be sufficient to produce thousands of nuclear weapons if improperly handled.

Stefano Buono, founder and chief executive of Newcleo, defended the strategy, arguing that converting plutonium into reactor fuel would ultimately reduce long-term nuclear liabilities for the United States.

Critics, however, say the initiative raises unresolved questions about transportation, storage, safeguards, and the potential diversion of weapons-grade materials.

The Department of Energy said the program could help participating companies attract private financing, though officials have not yet detailed how the government intends to guarantee the long-term safe handling and oversight of the plutonium stockpiles.