Trump White House Pushes Nuclear Startups Toward Plutonium-Fueled Reactors

The U.S. government is looking for new ways to deal with its long-standing plutonium stockpile problem by encouraging nuclear startups to use some of the material to power advanced reactors.

During the Cold War, the United States produced roughly 100 tons of plutonium for nuclear weapons. As portions of the country’s nuclear arsenal were later dismantled, the government was left with large quantities of radioactive material that now remain stored in highly secure facilities.

On Tuesday, the Department of Energy announced that five nuclear startups have been selected to begin negotiations to receive portions of surplus plutonium for future reactor projects. The government had previously identified around 34 tons of plutonium for potential disposal.

The selected companies include Oklo, Standard Nuclear, Shine Technologies, Flibe Energy, and Exodys Energy.

The initiative reflects growing government interest in advanced nuclear technology as energy demand rises, particularly from AI infrastructure and large-scale data centres.

Energy Secretary Chris Wright previously served on Oklo’s board before joining the administration and has since said he divested his shares. OpenAI CEO Sam Altman, who previously chaired Oklo’s board following its merger with AltC, stepped down from the role last year.

Several of the selected startups are already designing reactors capable of using plutonium-based fuel. Oklo is developing reactors that can operate on both traditional uranium and plutonium fuel. Exodys Energy is developing systems that use mixed oxide fuel (MOX), which combines uranium and plutonium. Flibe Energy is also building reactor concepts designed to run on plutonium and other nuclear by-products.

MOX fuel is already produced in countries like France. The U.S. once attempted to build its own MOX production facility in South Carolina. Still, the project was cancelled during the first Trump administration after years of delays and budget overruns.

However, the proposal has raised security concerns because the plutonium originated from nuclear weapons programs. Critics argue that transporting and reusing the material could pose additional risks rather than permanently disposing of it.

The selected startups will now enter into more detailed negotiations with the Department of Energy regarding fuel handling, transportation, and security requirements associated with managing plutonium-based reactor fuel.