TL;DR
Small nuclear reactors promise power plants built like airplanes: made in a factory, shipped and bolted together, instead of poured in concrete for a decade at each site. That idea just took a physical step. On Oct. 29 NuScale, which holds the only small-reactor design approved by U.S. regulators, signed a contract with South Korea's Doosan Enerbility to build the first production-quality part of its reactor module. It is real hardware, not a study. What is still coming is the part that matters most: a buyer. No customer has signed a binding order for a NuScale plant, and this contract names none. If one signs, a factory line would already be warming up; if not, this part stays a proof that the factory can do it.
Below the line, for paid subscribers: The full story: where it stands, how we got here and what's dated next; our Odds board on 5 milestones, starting with "NuScale signs a binding customer order by 2027"; our labeled speculation on what it adds up to; and every source.