US government eyes plutonium for nuclear reactor fuel

On Tuesday, the Department of Energy (DOE) announced it has selected five nuclear startups to enter into negotiations to receive plutonium. The material could potentially power nuclear reactors. The five selected startups are Oklo, Standard Nuclear, Shine Technologies, Flibe Energy, and Exodys Energy.

The U.S. government is seeking to manage a Cold War-era legacy. During the Cold War, the U.S. manufactured around 100 tons of plutonium for nuclear weapons. As those stockpiles were dismantled, the radioactive material was placed in high-security facilities. The Department of Energy has identified 34 tons of this plutonium for disposal. Managing this material is a long-term challenge, as the isotope has a half-life of 24,000 years.

The startups plan to use different methods to process the material. For instance, Exodys Energy is developing a reactor designed to operate using plutonium as part of mixed oxide fuel, or MOX—a blend of uranium and plutonium. While MOX is currently produced in France, previous U.S. plans to manufacture it in South Carolina were canceled after the project blew through budgets and timelines. Meanwhile, Newcleo, a U.K.-based partner of Oklo, intends to build its own MOX fuel fabrication facility nearby. Oklo itself is developing a reactor that can run on both traditional uranium and plutonium.

However, the plan faces criticism due to the security risks of handling the material. Critics argue that repurposing plutonium as fuel introduces security concerns. Scott Roecker, vice president at the Nuclear Threat Initiative, expressed concerns about the approach. “Countries have tried this before, and they concluded that, as nice as it would be to use that plutonium as fuel, it’s really just a liability and we need to dispose of it permanently,” Roecker said.

For the startups, the next step is to enter into negotiations with the government over security and the transportation of the plutonium. Energy Secretary Chris Wright was previously on Oklo’s board, but he resigned when he joined the administration and said he has divested his shares. Sam Altman also previously served as Oklo’s board chair, resigning the position last year.

Why it matters

The Department of Energy is initiating negotiations with five nuclear startups to repurpose Cold War-era plutonium as reactor fuel, a move aimed at addressing long-term radioactive waste storage.