The US nuclear fuel supply chain faces a deepening shortfall just as the country prepares for what industry insiders are calling a second nuclear age, with uranium mining capacity mothballed, enrichment plants underutilised, and a 2028 deadline to cut off Russian supplies bearing down on the sector.
Nuclear startup Antares fired the starting gun in June when its Mark-0 microreactor became the first advanced reactor to achieve criticality under a Trump administration pilot programme. According to World Nuclear News, the demonstration took place at Idaho National Laboratory under US Department of Energy authorisation, beating a 4 July deadline.
Power Magazine reports the Mark-0 is a sodium heat-pipe-cooled microreactor fuelled by high-assay low-enriched uranium (HALEU) tri-structural isotropic (TRISO) fuel compacts, the same category of advanced fuel that next-generation reactors require and that the existing supply chain struggles to produce at scale.
Roughly 98% of the uranium consumed by US reactors is imported. Congress has already legislated to ban enriched uranium imports from Russia in 2028, a country that currently dominates the global enrichment market.
Mining Bottleneck Threatens the US Nuclear Fuel Supply Chain
Canada-based Cameco, the top North American uranium miner, is sounding the alarm. About 30% of its uranium mining capacity is currently shut in, primarily in the United States, company president Grant Isaac said.
‘I’m getting increasingly worried about it,’ Isaac told Fortune. ‘As the demand is going up, we need to embrace the notion of long-lead items and apply that to uranium as well, because we’re just not able to explore for, find, permit, construct, and commission mines in the timeframe that you build a nuclear reactor.’
Bringing a new mine online can take 15 to 20 years, Isaac said. If uranium supply cannot keep pace with reactor construction, prices (and eventually power prices) will soar.
‘The demand that’s building for new reactors and all the excitement hasn’t found its way fully upstream to uranium,’ he said. ‘Over the next year or two, I think you’re just going to see a lot more people paying attention to it.’
AI hyperscalers are signing power contracts with nuclear developers for next-generation light-water reactors, small modular reactors and microreactors. They are not yet investing in the uranium mining and refining those reactors will need.
‘The nuclear industry is in a total renaissance,’ said Christo Liebenberg, co-founder and president of laser uranium enrichment startup LIS Technologies. ‘But it doesn’t matter what type of reactor; they all need nuclear fuel.’
Enrichment Capacity Falls Far Short of Demand
There is currently only one active enricher in North America: London-based Urenco‘s National Enrichment Facility in Eunice, New Mexico. The plant fulfils about one-third of US enrichment demand.
Urenco announced in June that it plans to expand the site, increasing capacity by nearly 50% by 2036 and adding production of HALEU fuel required by next-generation reactors. Even so, Liebenberg called it ‘a small drop in the ocean of what’s needed.’
If the US were to reach the White House’s target of quadrupling nuclear capacity from about 100 gigawatts today to 400 gigawatts by 2050, current US enrichment capacity would fulfil only 7% of total demand.
To close that gap, the Trump administration awarded $900 million each to Paris-based Orano, Centrus Energy and General Matter for enrichment plants in Tennessee, Ohio and Kentucky respectively. Orano is also requesting a federal licence to build a $5 billion enrichment facility near Oak Ridge, Tennessee, dubbed Project IKE.
LIS Technologies is aiming to bring its LIST Island facility in Tennessee online by the end of 2032, rivalling Urenco’s New Mexico plant in capacity, Liebenberg said.
One further complication clouds investment decisions across the entire US nuclear fuel supply chain: companies are receiving waivers to continue buying Russian uranium until the 2028 ban takes effect, and some fear new loopholes could reopen if a Ukraine peace deal changes the geopolitical calculus.
‘The West needs to be really clear that the Russians are out, and that the Russians are staying out,’ Isaac said. ‘That will help underpin real investments in Western energy production.’
Urenco’s planned expansion to nearly 50% greater capacity by 2036 represents the most concrete near-term addition to Western enrichment supply, but analysts and industry executives agree the build-out across the full fuel chain must accelerate substantially before the first wave of new reactors comes online.
