The detonation of the atomic bomb nicknamed “Smokey,” as part of Operation PLUMBBOB in the Nevada desert. 1957. (Photo by © CORBIS/Corbis via Getty Images)
Corbis via Getty Images
As AI drives rising energy demand, the Trump Administration is exploring an unconventional energy source: surplus nuclear-weapons-grade plutonium from the Cold War. In May 2026, the Department of Energy, under its Surplus Plutonium Utilization Program, selected five companies—Oklo, Flibe Energy, Exodys Energy, SHINE Technologies, and Standard Nuclear— to examine whether the excess plutonium can be converted into fuel for advanced nuclear reactors. The initiative provides an opportunity for the country to turn what has long been regarded as a costly disposal challenge into a source of domestic energy. We know the physics works. The question is whether it can be made economically viable.
Why Is the DOE Turning to Plutonium?
Plutonium-239 is a transmutation product of uranium-238. It is produced in a nuclear reactor when uranium-238 absorbs a neutron to become uranium-239, which then undergoes a two-step beta-decay chain: first into neptunium-239, then into plutonium-239. The material is widely known for its use in nuclear weapons and can generate a significant amount of energy even in small quantities. To put this in perspective, one kilogram of plutonium can generate about 8 million kilowatt-hours of electricity in a conventional thermal reactor—enough to power approximately 750 average American homes for a year. In an advanced fast reactor, which can fission plutonium more completely, the recovered energy would be considerably higher.
Until now, the U.S. has faced a disposal issue from weapons-grade plutonium remaining from dismantled Cold War-era warheads. The DOE currently has more than is needed for national security purposes, with a surplus of about 60-tonssupply. Disposing of that material would be complex and expensive. Estimates put the cost of the previous “dilute and dispose” initiative at $20 billion over 30 years. Dilution would involve blending the weapons-grade plutonium down so that it could not be used to manufacture bombs and hiding it in temporary storage, possibly in Nevada. It has been 81 years since the U.S. deployed atomic bombs in World War II; however, America still lacks a permanent and centralized nuclear waste facility. In the meantime, the DOE’s surplus plutonium must remain in secure storage and requires ongoing monitoring and safeguarding—another expense.
The DOE initiative could provide a solution by allowing private companies to access 20 metric tons (MT) of surplus plutonium for recycling, processing, and manufacturing fuel for advanced nuclear reactors.
ZARECHNY, RUSSIA – JUNE 27: An interior view of the core of the Russian Fast Breeder Reactor on June 27, 2017 in Zarechny, Svedlovsk Oblast, Russia. Journalists were allowed inside the core of the reactor for the first time. The worlds only commercially operating fast breeder reactor is situated in the Ural Mountains of Russia at the Beloyarsk Nuclear Power Plant, not far from Russias fourth largest city Yekaterinburg. The Russians are today the global leaders in fast breeder reactors having operated a fast breeder reactor called BN 600 since 1980 and BN 800 more recently. Fast breeder reactors produce more fuel than they consume and use plutonium and uranium as fuel and liquid sodium is used as coolant. India is also making a Prototype Fast Breeder Reactor at Kalpakkam. This was the first media glimpse of the power plants. (Photo by Pallava Bagla/Corbis via Getty Images)
Corbis via Getty Images
How Can Plutonium Be Used as Reactor Fuel?
Plutonium can be mixed with depleted uranium to create mixed-oxide (MOX) fuel to power existing thermal (light-water) civilian nuclear power reactors, properly licensed and modified to include it in the fuel mix or in fast reactors.
Thermal reactors use a moderator to slow down neutrons, increasing the probability of fission. Fast reactors do not use a moderator, allowing neutrons to remain at high speeds. This allows for more complete utilization of nuclear fuel. Fast reactors include fast-breeder designs, which can produce more plutonium than they consume by converting uranium-238 into fissile material.
Sodium-cooled fast reactors are the most historically developed design in the latter category. While the United States does not currently operate any commercial fast reactors, Russia has developed two: the BN-600, which has been operating since 1980, and the BN-800, which has been operating since 2016. A third, the BN-1200, which will be the world’s largest of its type, is currently in the early stages of deployment.
Advanced nuclear reactors are currently under development in the U.S. by a range of private companies and research programs. They can use fuel more efficiently than conventional reactors and, in some cases, recycle nuclear materials such as plutonium. Some U.S. light-water reactors could potentially be adapted to use MOX fuel with licensing, infrastructure, and supply chain modifications, making it the most immediate pathway for plutonium utilization.
Is the Project Economically Viable?
Given disposal costs, the DOE initiative aims to explore whether the material could serve as an energy source for advanced nuclear reactors.
This is not the first time the U.S. has attempted to address the issue. The Savannah River MOX project saw cost estimates climb from about $4.9 billion to roughly $17 billion as its projected completion date slipped to 2048, ultimately leading to the project’s termination in 2018. The economics of plutonium are complex, as there is no commercial market price. The bulk of the cost of using plutonium would not come from the fuel itself, but from the additional infrastructure it would require.
Estimates for sodium-cooled fast reactors—the leading technology for plutonium burning—suggest that first-of-a-kind units could cost several billion dollars each, with costs potentially declining in later deployments as designs mature and supply chains scale.
Can Private Nuclear Energy Take Charge?
Unlike previous government-led efforts, the current initiative attempts to shift development toward the private sector. The companies selected by the DOE for the current project are early-stage or mid-sized developers that have acquired partnerships and financial backing.
Oklo, the largest of the group, reported $2.5 billion in cash and marketable securities as of Q1 2026, supported in part by capital raises, including a $1.2 billion At-the-Market (ATM) offering. The company is partnering with Newcleo, a European developer of advanced nuclear reactors, which would provide potential capital support.
SHINE has raised $240 million in equity funding, bringing total investor backing to $1 billion.
It is also important to note the role of AI companies in energy development. Sam Altman was an early backer of Oklo and previously served as its chairman of the board, formally stepping down in 2025. In January 2026, Meta announced an agreement with the company to develop an energy campus under a prepayment structure, reflecting efforts by large technology firms to secure long-term energy supplies.
Do the Risks Outweigh the Benefits?
Since the announcement, the project has faced opposition. Among critics is Senator Edward Markey of Massachusetts, who has expressed concerns about the proposed plans, citing security risks. Those opposed argue that expanded handling of weapons-grade plutonium could increase proliferation risks and create pathways for illicit nuclear weapons development.
Supporters of the program argue that the material already exists and requires management and monitoring, regardless of whether it is used as fuel or stored. The question is how to manage plutonium in the safest way while extracting economic value.
The program has also drawn scrutiny for potential conflicts of interest, including concerns about Secretary of Energy Chris Wright’s prior ties to Oklo. Transparency and oversight will be crucial for public trust.
What Can History Teach Us?
The U.S. has maintained a restrictive stance on plutonium reprocessing since the 1970s. In 1976, President Gerald Ford’s administration issued a statement aimed at limiting the spread of plutonium and reducing proliferation risks. The policy placed a de facto moratorium on commercial reprocessing and recycling of plutonium unless proliferation risks could be addressed, citing concerns that separated plutonium could be diverted for use in nuclear explosives.
His successor, President Jimmy Carter, expanded that approach in 1977, indefinitely deferring the reprocessing and recycling of plutonium and reducing federal support for the breeder reactor program. In 1978, Carter vetoed the Department of Energy Authorization Act of 1978, in part because it funded the Clinch River Breeder Reactor project, which he sought to terminate. The project was canceled by Congress in 1983.
These policies reflected Cold War-era concerns about nuclear proliferation, but they also had lasting negative consequences for the U.S. nuclear industry. While the U.S. moved away from using plutonium and building breeder-reactors, other countries continued development. France, Japan, and Russia developed and began operating fast-breeder reactors over the years, while the U.S. lagged behind.
Looking Forward
Moving forward, the solution is to blend down or process excess plutonium into fuel, but we must do so in a way that is technologically sound, economically viable, and as secure as possible.
As artificial intelligence drives rising electricity demand and growing interest in advanced nuclear technologies , policymakers are revisiting questions that have shaped U.S. nuclear policy for nearly five decades. With careful planning, advanced reactors, and strategic investment, the nation may have an opportunity to turn billions of dollars in surplus nuclear material from a Cold War liability into a valuable energy resource while addressing environmental concerns.
