For decades, the United States has struggled with what to do with surplus plutonium generated during the Cold War and from dismantled nuclear weapons programs. Much of the material has remained in long-term storage under strict security controls, with federal agencies exploring costly disposal and containment strategies for years.

Now, the U.S. Department of Energy is attempting to turn part of that stockpile into reactor fuel through its Surplus Plutonium Utilization Program. The initiative seeks to convert designated surplus plutonium into fuel for advanced nuclear reactors instead of treating it solely as a long-term waste and security challenge.

As part of that effort, Oklo Inc. entered advanced negotiations with the DOE after the agency selected the company for the program. Oklo was one of five advanced nuclear companies chosen for negotiations, a move that investors viewed as a major step toward securing future reactor fuel supplies.

Shares of Oklo rose more than 6% in early trading Tuesday following the announcement.

Turning waste into fuel

Oklo plans to work with newcleo, a European advanced reactor company that brings fuel development expertise and potential project funding to the effort. The companies said the program could help transform surplus plutonium from a long-term storage liability into usable reactor fuel.

They aim to use the material in advanced reactors to generate electricity while consuming it through fission under strict regulatory oversight. Oklo co-founder and CEO Jacob DeWitte said fuel supply limits remain one of the biggest obstacles facing advanced reactor deployment.

“This program creates a pathway to use existing surplus material as bridge fuel for advanced reactors to bring more reactors online sooner,” DeWitte said. He added that material once intended for disposal could instead support electricity generation through fission.

newcleo founder and CEO Stefano Buono described the partnership as part of a broader effort to reduce nuclear liabilities through advanced fuel and reactor technologies. “The U.S. is taking a visionary approach to the fuel cycle,” Buono said. “We look forward to contributing to it.”

Expanding fuel infrastructure

The DOE selection also supports Oklo’s broader fuel sourcing strategy as the U.S. continues expanding domestic enrichment and fuel fabrication capacity. In October 2025, Oklo announced a strategic partnership with newcleo to develop advanced fuel fabrication infrastructure in the United States.

The companies said the initiative could include projects tied to surplus plutonium utilization. The agreement also outlined plans for up to $2 billion in investment through a newcleo-affiliated entity, subject to final documentation and industry conditions.

The companies continue working through regulatory steps tied to those projects. In February 2026, newcleo began pre-application engagement with the U.S. Nuclear Regulatory Commission for an advanced fuel fabrication facility and a lead-cooled fast reactor design intended for the U.S. market.

Advanced reactor push

The DOE program arrives as advanced nuclear developers seek reliable fuel supplies to support reactor deployment over the next decade. Many next-generation reactor companies face uncertainty around fuel availability because domestic enrichment and fabrication infrastructure remains limited.

Oklo has positioned fuel access as a central part of its long-term reactor deployment strategy. The company continues exploring multiple supply pathways while the U.S. government pushes to strengthen domestic nuclear fuel capabilities.