The project to build the world's first AP1000, China's Sanmen 1, reached a construction milestone when the third steel ring of the plant's containment vessel was hoisted into place. Work on the Westinghouse reactor is now back on schedule, despite falling six months behind at the end of last year.
|The third ring is lowered into place (Image: Sanmen Nuclear Power Co)
The steel ring, which makes up part of the containment vessel, was lowered into place on 12 September. Composed of 36 steel plates 44.5 mm thick, it is 11.7 metres in height and weighs in excess of 500 tonnes. Installation of the third ring means that the steel safety shell now rises 35.7 metres above ground level, according to the Sanmen Nuclear Power Co.
Sanmen 1 is one of two AP1000 pressurised water reactors being constructed at the site in Zhejiang province and is the lead unit of four AP1000 units currently being built in China. Construction is also under way on two AP1000s at Haiyang in Shandong province. Aris Candris, President and CEO of Westinghouse, told the recent World Nuclear Association Annual Symposium in London that all four AP1000 reactors are on course to commence operation between November 2013 and March 2015.
The 700 tonne containment vessel bottom head (CVBH) for Sanmen 1 was set in December 2009, some six months behind schedule, but by the end of May 2010, with the setting of the second containment vessel ring, this construction delay was recovered. By providing quick feedback, such delays could be eliminated on the following units. In the case of the CVBH, welding was carried out within a fully-enclosed building for the reactors planned for Haiyang, leading to much shorter fabrication times for the CVBH for Haiyang 1 compared with that for Sanmen 1. According to Candris, the quick schedule recovery and optimization of construction processes would not have been possible without using modular construction.
The next major milestone scheduled for Sanmen 1 is the installation of the reactor vessel and steam generators, which should take place in 2011.
Significant technology transfer was included in Westinghouse's contract for China's first four AP1000 reactors at Sanmen and Haiyang. At a press briefing following his speech, Candris admitted that it is possible that Westinghouse might not receive further contracts in China, although he expected that his company would have significant input in the next units. "We are negotiating with China for the next ten or so," he said.
Candris also noted that, within about two years, the biggest revenue stream for Westinghouse is likely to be from the new build market. In addition to China, "over 50 countries" have recently contacted Westinghouse regarding new build.
Researched and written
by World Nuclear News