What we know so far: The United States is opening part of its Cold War – era plutonium stockpile to help reduce reliance on Russian uranium and speed development of next-generation nuclear reactors. The initiative focuses on companies building fast reactors and small modular designs capable of recycling spent fuel and operating more efficiently than conventional nuclear plants.
The Financial Times reports that the Department of Energy has invited companies to apply for up to 19 metric tons of weapons-grade plutonium previously used in warheads. On Tuesday, the DoE said it plans to select the first group of recipients by the end of December, with additional awards possible thereafter. The initiative adds a new dimension to President Donald Trump's broader campaign to strengthen US energy independence and revive the domestic nuclear sector, a centerpiece of his industrial policy as electricity demand rises for the first time in decades.
Most advanced reactor designs under development in the US rely on high-assay low-enriched uranium (HALEU), a fuel enriched to between 5 and 20 percent uranium-235. Russia currently controls most commercial-scale production, leaving American developers without a domestic supply.
Although the United States banned imports of Russian uranium products in 2024, domestic output remains negligible – less than one metric ton per year, according to Energy Department data. The reliance on Russia has created a critical bottleneck for companies developing small modular reactors (SMRs), which generate up to 300 megawatts of power and which proponents tout as safer, more flexible alternatives to conventional plants.
In May, President Trump signed four executive orders aimed at expanding nuclear capacity and securing reactor fuel. Two of those directed the Department of Energy to identify surplus nuclear materials and repurpose them for civilian energy use.
California-based startup Oklo – backed by OpenAI chief executive Sam Altman – and French nuclear firm Newcleo are among the first applicants seeking access to the plutonium surplus. Companies must outline detailed plans for recycling, processing, and manufacturing fuel derived from plutonium. They must also outline comprehensive safety and security protocols. Applicants selected for the program may also receive expedited consideration for licenses from the Nuclear Regulatory Commission, a requirement for operating a nuclear facility.
Critics warn that repurposing plutonium for commercial purposes carries serious proliferation and security risks.
"Unless you get assurances that they're going to protect it as though it is a nuclear weapon, then it's going to increase vulnerability to theft," Edwin Lyman, a physicist with the Union of Concerned Scientists, told the Financial Times.
Last week, Newcleo announced plans to invest up to $2 billion in US advanced fuel fabrication and manufacturing infrastructure as part of a joint project with Oklo. Stefano Buono, the company's founder and chief executive, said the partnership reflects long-term confidence in fast-reactor technologies designed to recycle used fuel.
"With the 92,000 tons of spent fuel that the US has, they could have 100 years of energy independence," Buono said.
Despite optimism among reactor startups, similar initiatives have collapsed before. In 2018, the federal government abandoned an earlier plan to use plutonium for civil nuclear fuel because of rising costs associated with converting weapons-grade material into usable fuel.
It remains unclear whether the administration has legal authority to distribute plutonium from the national stockpile, since Congress oversees US nuclear waste policy. The Department of Energy did not respond to a request for comment.
US opens Cold War plutonium stockpile to jump-start next-gen nuclear reactors
