The vision of a U.S. nuclear power renaissance has a blind spot – uranium fuel – in the near term and long, according to a Stanford University-led industry meeting.
AI data centers, reshoring of manufacturing, and the electrification of transportation, buildings and other sectors have heightened demand for affordable, reliable power around the clock. Nuclear energy could check those boxes, its proponents say, but supplies of enriched uranium for existing power plants are tight, vulnerable to geopolitics, and getting more expensive. New fuel forms for advanced reactors, meanwhile, offer promise, but scaling them affordably and in parallel with conventional fuel systems could squeeze conventional fuel markets even more.
Over 100 leaders across the nuclear fuel sector, utility executives, government regulators, and reactor designers and developers gathered in July in Arlington, Virginia, to examine these barriers and identify possible ways to overcome them. The Nuclear Fuel Cycle Roundtable was organized by STEER , an initiative of Stanford University's Precourt Institute for Energy and SLAC National Accelerator Laboratory . Congressman Chuck Fleischmann (R-Tenn.), chair of the House Energy & Water Development Appropriations Subcommittee, opened the discussion with a keynote address.
On Dec. 29, Nature Energy published a summary of the insights that emerged from the meeting. The Trump administration has been moving to strengthen the U.S. nuclear fuel supply chain. On Jan. 5, the U.S. Department of Energy announced $2.7 billion in contracts to three domestic fuel enrichment companies for conventional reactors and next-generation reactors now in development.
"As in any hard-tech sector, investment enthusiasm can often be driven by exuberance," said the founder and team lead of STEER, Adrian Yao , who spearheaded the roundtable. "We sought to focus on the fuel supply chain while much of recent private investment activity has been focused on current- and next-generation reactors amid this new nuclear groundswell. Specifically, our objective is to identify 'what must be true' for the fuel supply chain to support the growing demand."
STEER, which is funded in part by the U.S. Department of Energy , analyzes emerging energy technologies from supply chains to deployment roadmaps in order to inform what to build, where to innovate, and how to invest. The Precourt Institute is part of the Stanford Doerr School of Sustainability .
Conventional nuclear fuel
Immediate growth in nuclear power production – like last year's announcement of restarting a Three Mile Island Nuclear Generation Station reactor – depends on the deeply international supply chain for nuclear fuel. That chain has four links:
- mining the uranium;
- converting it to a gas form;
- enriching it to increase the fissile U-235;
- and fabricating uranium pellets and fuel rods for shipment to nuclear power plants.
The industry discussion stressed that several links in this chain are at risk. Four countries dominate mining: Kazakhstan, Namibia, Australia, and Canada. The United States mines very little uranium, due to lower-grade ore and higher costs. While most meeting participants did not express strong concerns about mining due to friendly partners, some stressed the importance of rebuilding U.S. domestic mining, highlighting uranium as a critical mineral. Also, the largest producer – Kazakhstan – continues to seek strategic autonomy from its interdependence on Russia and, increasingly, China. This may be viewed as an opportunity for the United States.
Only five facilities worldwide convert mined uranium on a large scale into the gas needed for enrichment. This step may pose one of the most critical pinch-points in the supply chain. Markets for these services have been turbulent in recent years, with price dips and spikes forcing western plants into shutdown and restart cycles. Stockpiles of converted uranium gas are shrinking. Without big, long-term contracts, conversion company executives at the July roundtable expressed hesitation to expand capacity.
Uranium buyers, meanwhile, are reluctant to pen long-term agreements inflated by today's high prices. Even when buyers are prepared to sign, the incremental demand is significantly less than the stepwise supply added by capacity expansions. To break this deadlock, several meeting participants suggested that U.S. federal and state governments could act as customers of last resort for new facilities.
"This could provide the payment certainty required for investment in new conversion capacity," said Yao, PhD '25.
Enrichment, the third stage of the nuclear fuel supply chain, remains heavily concentrated: Nearly half of global capacity is in Russia, with only two major commercial enrichers operating in the United States and western Europe. This poses a strategic challenge for the United States, which relies on Russia for nearly 30% of its enriched uranium supply. In response to Russia's invasion of Ukraine, Congress passed legislation in 2024 to ban enriched uranium imports from Russia. Several European countries are also working to reduce their dependence on Russian fuel.
The United States is self-sufficient only in the final fourth step of the conventional fuel supply chain: making ceramic pellets from enriched uranium and producing fuel rod assemblies. Meeting attendees generally agreed, however, that for national and economic security the United States should develop capacity across the entire supply chain for conventional reactors.
The U.S. ban on enriched uranium from Russia sparked some interest in investment to do just this, but the investments stalled due to concerns about the ban's effectiveness and durability. For example, waivers can be granted if alternatives to Russian supplies are insufficient, and Russia may be able to circumvent the ban via other countries.
"Many participants suggested that China could circumvent the ban by 'flag swapping' Russian uranium in U.S. markets," said Bennett Johnson , MBA '24/MS '25, a co-author of the report and STEER's strategic partnerships lead. "Other participants questioned how long the political support for the ban would last. Investors want some certainty that it would last at least 10 years."
Next-generation reactors
The meeting turned its attention to next-generation fission reactors now mostly in development, generally known as "Gen IV." Fuel for these new generators will need a much higher degree of enrichment. One ton of Gen IV nuclear fuel is estimated to require almost 40 tons of mined uranium, compared to less than 10 tons for conventional nuclear fuel. Those higher degrees of enrichment translate into fuel that generates electricity for a longer time, so the impact on mined uranium is less severe than four to one. Still, fuel suppliers at the roundtable said that without significant additional mining, conversion, and enrichment capacity, next-generation reactors could further stress uranium supplies for the existing nuclear fleet, already burdened with high fuel costs.
Reactor designers and fuel manufacturers working on next-generation advanced reactors noted that the complexity and limited commercial experience with new fuel forms could lead to low fabrication yields and high costs.
Access to test reactors, critical for validating fuel performance and refining manufacturing specifications, is limited, the designers and fuel manufacturers emphasized. Today the only operating Gen IV reactor is in China. Standardization of chemistries and fuel specifications, particularly through coordination between reactor designers and fuel fabricators, was proposed to accelerate the fuel manufacturing learning curve.
Broadly, the Nuclear Fuel Cycle Roundtable highlighted the need to reduce technological, economic, and policy uncertainty throughout the nuclear fuel supply chain to stimulate growth. Primary avenues for doing so potentially include strategic global partnerships and coordination of fuel standards; additional clarity on enforcement of geopolitical policy actions, like the ban on uranium from Russia; R&D to support efficient and low-cost manufacturing of nuclear fuels for advanced reactors; and independent and timely analysis.
"Combining Stanford's convening power with our impartial investigation enables us to help answer 'what to build, where to innovate, and how to invest' while being grounded in the realities of deployment," said William Chueh , director of the Precourt Institute, as well as the Kimmelman professor of materials science and energy science at Stanford, and of photon science at SLAC.
