China Pours First Concrete for Fourth Hualong One Reactor at San’ao
China General Nuclear (CGN) poured first concrete for the nuclear island of San'ao unit 4 on November 10, a step the company says “marks the official start of the main construction of the unit,” according to World Nuclear News and NucNet. The pour makes San'ao, on the coast of Zhejiang province, the latest Chinese site to have a fourth Hualong One reactor under way.
Six reactors, three phases
San'ao is being built in three phases of two Hualong One units each. Phase I — units 1 and 2 — received State Council approval in September 2020. Unit 1 reached first criticality in February 2026, was connected to the grid in March and entered commercial operation on April 29, a span of roughly five years and four months from its own first-concrete pour. Unit 2 has completed both cold and hot functional testing and fuel loading, with first power to the grid scheduled for 2027.
Phase II — units 3 and 4 — was approved by China's State Council in August 2024 as part of a package of eleven reactors nationwide. Unit 3's nuclear island broke ground on December 19, 2025; unit 4's followed roughly eleven months later. A third phase, units 5 and 6, is already planned for the same site. CGN says San'ao is the first nuclear project in the Yangtze River Delta to use the domestically designed Hualong One, and the first Chinese nuclear plant to bring in private capital.
A project with capacity to match a mid-sized grid
Each Hualong One unit is a pressurised-water reactor in the roughly 1,100–1,200 MWe gross class, the same design now standard across most of CGN and China National Nuclear Corporation's new coastal builds. Once all six San'ao units are operating, CGN says the site will generate more than 54 terawatt-hours of electricity a year — enough, the company says, to displace over 16 million tonnes of standard coal and cut almost 50 million tonnes of CO2 emissions annually.
The project company, Cangnan Nuclear Power, is less than half state-utility owned: CGN holds a 46% stake, automotive conglomerate Geely Technology Group holds 2%, and the remaining 52% sits with other state-owned enterprises CGN has not individually named — an ownership structure the company points to as evidence of its push to bring outside capital into nuclear construction.
Part of China's fastest-moving nuclear fleet
San'ao's pace mirrors a broader acceleration in Chinese nuclear construction this year. CGN's Changjiang unit 3 Hualong One reactor, on Hainan island, entered commercial operation; the Tianwan 7 unit reached minimum controllable power; and construction began at Xuwei on what China describes as the world's first commercial high-temperature gas-cooled reactor unit. Beijing's State Council approved eleven new reactors in 2024 alone, and Chinese utilities have been pouring first concrete on new units at a pace unmatched anywhere else in the world over the past two years — a buildout that is reshaping global nuclear supply chains even as Western developers work through first-of-a-kind regulatory reviews for small modular designs such as the one the US NRC cleared for construction in Texas this week.
Sources
- World Nuclear News, “Fourth Hualong One under construction at San'ao site,” November 10, 2026 — construction timeline, ownership, output figures.
- NucNet, “Pouring Of First Concrete Begins For Nuclear Island At China's Sanao-4,” November 11, 2026 — confirmation of the pour and site unit count.
Illustrative image. Photo: Nuclear Regulatory Commission, Public domain, via Wikimedia Commons — source
