Inside the race to rebuild America’s fuel supply chain for a ‘second nuclear age’

Nuclear startup firm Antares successfully flipped the switch on its Mark-0 microreactor in June, first to the finish line in the Trump administration’s pilot program race—with a July 4 deadline—for the next generation of reactors to achieve criticality. With the U.S. on the verge of a potential “second nuclear age,” a bevy of projects are underway to power the AI boom. But almost the entire North American nuclear fuel supply chain is woefully lacking—from uranium mining to fuel-pellet fabrication—just as Congress bans imports of enriched uranium in 2028 from Russia, which dominates the industry. The AI hyperscalers are signing contracts with nuclear developers for next-generation light-water reactors, as well as newly developed small modular reactors (SMRs) and microreactors. But they’re not yet investing in the uranium mining and refining required for nuclear power. Roughly 98% of the uranium consumed by U.S. reactors is imported. “The nuclear industry is in a total renaissance,” said Christo Liebenberg, co-founder and president of the laser uranium enrichment startup LIS Technologies. “But it doesn’t matter what type of reactor; they all need nuclear fuel.” “It doesn’t stop there,” Liebenberg told Fortune. “It trickles down to the whole fuel supply chain—all the way from uranium mining. I think [hyperscalers] need to jump in very urgently because the reactors need fuel. It’s for their own good to start developing that supply chain.” Already, the Bill Gates-backed TerraPower recently broke ground in Wyoming to build the first commercial nuclear plant in 13 years, and Kairos Power is building a commercial-scale demonstration plant in Tennessee. A series of previously shuttered nuclear plants also are slated to come back online in Michigan, Iowa, and Pennsylvania, the latter of which is Three Mile Island, reborn as the Crane Clean Energy Center to power Microsoft’s data centers. And that’s just the tip of the—isotope. U.S. electricity demand is expe