Correction: Piefer said once plutonium generates power it can no longer be used to make bombs, not it is no longer dangerous.
The Biden administration is moving ahead with a controversial plan to convert Cold War-era plutonium into fuel for next-generation reactors, initiating advanced talks with five private firms to develop 19.7 metric tons of various plutonium forms, some sourced from dismantled nuclear warheads. Officials present the initiative as a component of a broader strategy to expand U.S. nuclear generation capacity as demand from data centers escalates, but the proposal raises serious safety, security and cost questions.
Plutonium is an exceptionally hazardous substance. In addition to being potentially usable in an explosive device, even microscopic particles of the element pose grave health risks if inhaled. The material’s long radiological persistence - a half-life of roughly 24,000 years - compounds concerns about long-term handling and storage.
"This is weapons-usable plutonium," said Ross Matzkin-Bridger, who has worked on securing plutonium materials worldwide with the U.S. Department of Energy and the National Nuclear Security Administration. "I’m very concerned that there are big pieces of the risk that the taxpayers are going to be tackling."
Program aims and participants
Last month, the administration disclosed it had selected five firms to enter advanced discussions over plans to process and repurpose almost 20 metric tons of plutonium into fuel suitable for certain reactor designs. Officials framed the effort as part of an initiative to help achieve the administration’s goal to significantly expand U.S. nuclear power capacity by mid-century, a policy driven in part by rising electricity needs from hyperscale data centers.
Company representatives and federal officials say the selected firms must present detailed safety and security plans covering stabilization, packaging, transport and storage of any plutonium they would handle. The U.S. Department of Energy (DOE) warned that a majority of workers at any facility dealing with plutonium would likely require the highest level of security clearances.
A spokesperson for the DOE’s Office of Nuclear Energy emphasized that the companies must demonstrate robust measures for material protection. "DOE does not expect to pay for the specialized proliferation, security, and health protections required to process surplus plutonium," the spokesperson said, indicating an expectation that private partners will shoulder a substantial portion of the specialized protections.
Industry positions and oversight
Oklo, one of the companies engaged in the advanced talks, believes plutonium can function as a practical fuel source in the near term while the U.S. works to expand domestic supplies of uranium, including HALEU, a more highly enriched fuel largely produced overseas today. Bonita Chester, an Oklo spokesperson, said using plutonium as a fuel would avoid the need to pursue a previously planned government program to dilute and dispose of the material. The administration paused that disposal effort when it first announced the fuel conversion plan last year.
Chester said Oklo would invest in transport, fuel fabrication infrastructure and required licensing work, including safety, security and safeguards, but did not provide a company estimate for those costs.
Energy Secretary Chris Wright previously served on Oklo’s board before joining the administration. A DOE spokesperson said Wright was not involved in Oklo’s selection, forfeited unvested shares, and recused himself from matters specifically involving the company.
Carl Perez, chief executive of Exodys Energy, which proposes to build a federal-land facility to process surplus plutonium into fuel, said a project cannot receive required U.S. authorizations and licenses without fully addressing worker protection, safety and material safeguards according to recognized standards.
Greg Piefer, CEO and founder of SHINE Technologies, stressed his company’s experience in processing radioactive materials and noted a key technical point: once plutonium undergoes fission inside a reactor it can no longer be used to construct a nuclear explosive. "One of the most responsible things we can do with weapons-grade plutonium is to burn it," he said.
Standard Nuclear and Flibe Energy, two other firms named in the advanced discussions, did not respond to requests for comment.
Security, licensing and cost concerns
Some members of Congress and former officials say the program will encounter substantial security-related expenses that could fall back on taxpayers. U.S. Representative Bill Foster, an Illinois Democrat and the only physicist in Congress, said the proposal raises alarm bells for him. "My brain goes on high alert" when he hears about the plan, Foster said, warning that maintaining protection "robust against terrorism" could be extremely costly and that stakeholders must scrutinize the economic case for such facilities.
Former Energy Secretary Ernest Moniz, who led the department under a previous administration, argued that diluting and disposing of surplus plutonium may be an easier and less expensive route. "My expectation is that you will find the government paying for a hell of a lot of what’s going on here, including all the security you would need around weapons-grade plutonium," he said, forecasting significant public expenditure if the processing route proceeds.
Historical context and technical pathways
The U.S. has a fraught history with plans to convert weapons plutonium into reactor fuel. In 2000 the country agreed to produce mixed oxide (MOX) fuel from surplus weapons plutonium to run in conventional reactors. That MOX effort was cancelled in 2018 by the prior administration, which said the program would cost about $48 billion more than the roughly $7.6 billion already expended.
Oklo plans to use so-called fast reactors for plutonium fuel. The company says these reactors are more efficient than designs contemplated for MOX fuel and that, according to its internal calculations, one metric ton of plutonium consumed in a fast reactor could generate enough electricity to supply almost 1 million American homes for a year. Fast reactors, however, have only been used for research in the United States and have not operated as commercial power plants.
Implications for energy markets and infrastructure
Advocates argue that repurposing existing plutonium stocks could provide a domestic bridge to higher reactor output while the nation scales up uranium fuel production. Opponents and skeptics counter that unresolved questions about security, health protections, licensing timelines, and cost-sharing could delay or derail projects. The DOE’s stance that private companies should cover specialized security and proliferation protections does not resolve who ultimately bears the financial burden should programs require higher-than-anticipated government involvement.
The debate over converting weapons-grade material into fuel touches multiple sectors: the nuclear industry and reactor vendors, federal security and health agencies, energy consumers such as data-center operators, and regional infrastructure planners who would host any new processing or reactor facilities.
Next steps and outstanding uncertainties
The advanced talks mark a step toward potentially repurposing a substantial quantity of surplus plutonium, but they leave open many practical questions. Companies must gain extensive authorizations and clearances, design and fund safeguards and protection systems, and navigate a licensing pathway not previously used for commercial plutonium processing. Given the exceptional hazards of plutonium and the long record of debate over conversion programs, the outcome remains uncertain.
For now, the proposal proceeds as one element among several aimed at expanding U.S. nuclear capacity to meet growing demand. Whether it will scale into operational facilities, and at what cost and timeframe, depends on how the complex web of technical, security and regulatory challenges is resolved.