The chart where China’s reactor count climbs while everybody else’s goes sideways isn’t news to you at this point. You’ve seen it. What caught my attention last month was a photograph instead: a crane in Liaoning province holding what looks like an enormous steel party hat over an unfinished reactor building, with a handful of people standing back watching it come down.<\/p>\n
That party hat weighs about 1,100 US tons, and it isn’t a roof.<\/p>\n
China National Nuclear Corporation announced on August 28 that the outer dome of the containment building at Xudabao 1 was in place, and World Nuclear News wrote up the lift<\/a> the same day. The unit is a CAP1000, which is the Chinese version of the Westinghouse AP1000, going up on the coast near Xingcheng in Huludao.<\/p>\n Here’s the two-sentence version. A plant like this has a steel containment vessel, the pressure-tight can wrapped around the reactor itself, and then a concrete shield building wrapped around that, and the concrete is what’s built to take an earthquake or an airplane. The dome that just went on caps the shield building, and its main job is holding up a tank of water that sits above everything else.<\/p>\n The water is the whole point. If the plant loses power in an accident, valves open and that tank drains down over the outside of the steel containment on gravity alone. There aren’t any pumps in that sentence, and there isn’t anyone at a console either. Westinghouse’s own data sheet on AP1000 passive safety<\/a> puts the coping period at 72 hours, meaning three days of the reactor cooling itself with water falling downhill and warm air rising up a chimney. After that someone has to go refill the tank. That figure is Westinghouse’s, for the American design, and I can’t find a published English-language number from CNNC for its own version.<\/p>\n So the lid in that photo is structural, and what it’s holding up is basically a swimming pool. That’s where the weight comes from.<\/p>\n CNNC published the parts list, and it’s more ordinary than you’d expect for a nuclear component. The cone is 32 radial main beams, three ring beams and 96 steel cladding panels, with three steel platforms hanging off the bottom edge. You’re looking at a roof truss, scaled up until it needs its own crawler crane and its own weather window.<\/p>\n This is the part I keep coming back to. In February, State Power Investment Corporation set the outer dome on unit 4 at Haiyang, over in Shandong. At the start of June, crews at Lianjiang in Guangdong set one on unit 1 there, which we wrote about at the time<\/a>. Now Xudabao. Are they the same part? Put the three announcements side by side and the descriptions run word for word: 41 meters across, 11 meters tall, near 1,000 metric tons, 32 radial beams, 96 panels. So yes, as far as anyone outside the factory can tell, it’s one module built three times.<\/p>\n That’s the modular pitch working the way it’s supposed to. Build the awkward pieces in a factory, barge them to the site, and lift them in whole instead of welding them together in place while every other trade stands around waiting. It also means the crew running the third lift has watched two others go up this year, and repetition is how construction schedules get shorter.<\/p>\n The AP1000 has a rough history in America. Georgia Power dates construction of Vogtle units 3 and 4<\/a> to June 2009. Unit 3 entered commercial operation on July 31, 2023, and unit 4 on April 29, 2024. They’re still the only new reactors finished in the US in more than three decades.<\/p>\n Xudabao 1 got its construction license in November 2023 and had its outer dome on 33 months later. I want to be careful with that, because the two clocks aren’t measuring the same thing. Vogtle’s start date takes in the site work, a dome lift isn’t anywhere near a finished plant, and CNNC still has to install everything underneath the thing it just capped. But 33 months from a groundbreaking ceremony to the last big structural lift is fast by any yardstick American nuclear was using ten years ago, and pretending otherwise doesn’t help anyone.<\/p>\n If you want the longer version of that comparison, we’ve been through it with the giant prefab modules on both sides, the 950-ton steel room at Lufeng<\/a> and the 2.2-million-pound module at Vogtle<\/a>. The drawings match. The calendars don’t.<\/p>\n Units 3 and 4 at Xudabao aren’t CAP1000s at all. They’re VVER-1200s, supplied by Rosatom, and they got going in July 2021 and May 2022. CNNC has them scheduled to come online in 2027 and 2028, which puts the Russian pair in front of the American-designed pair sitting next to them. The launch ceremony for that Russian work ran by video link on May 19, 2021, with Xi Jinping in Beijing and Vladimir Putin in Moscow watching the foundation concrete go down for unit 3, according to the Kremlin’s own readout.<\/p>\n So one stretch of Liaoning coastline has an American reactor design and a Russian one rising within sight of each other, on the same grid, run by the same owner. I’d stop short of calling that unique, because I haven’t audited every construction site on the planet and neither has anyone else. It’s still a pretty odd thing to see in one photograph.<\/p>\n One caveat before you take any of this to the bank. Everything about the August lift traces back to CNNC, and the only outside reporting I can find is World Nuclear News writing up the CNNC announcement. NucNet covered the inner dome<\/a> in February and put that piece at roughly 780 metric tons, though Nuclear Engineering International reported it above 820, so even the pieces that got two write-ups don’t always agree. No one independent has been up on that shield building with a tape measure.<\/p>\n CNNC says units 1 and 2 are due to start generating in 2028 and 2029. The operators need somewhere to practice before then, and the full-scope control room simulator for the pair went into service in August: Gao Shunlong, chairman of the CNNC subsidiary that built it, called the commissioning a milestone in the project’s construction.<\/p>\n Image credit: CNNC<\/em><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":" The chart where China’s reactor count climbs while everybody else’s goes sideways isn’t news to you at this point. You’ve … <\/p>\nSo what’s a dome doing in a cooling system?<\/h2>\n
It’s the third one of these craned up in China this year<\/h2>\n
The same reactor took 14 years in Georgia<\/h2>\n
There are two Russian reactors on the same site<\/h2>\n