New Construction Milestones for AP1000 Units

Construction of four AP1000 units—the first new nuclear reactors in the U.S. in decades—is moving along at Vogtle 3 and 4 in Georgia and at the V.C. Summer nuclear power plant in South Carolina. In January, Westinghouse, which is spearheading construction of the units, marked a key milestone as it placed the first steam generator at V.C. Summer Unit 2.

The steam generator, supplied by South Korean firm Doosan, is a major component for the plant’s steam-supply system (Figure 3). According to Westinghouse, AP1000 plant steam generators are based on a proven design with multiple enhancements, including anti-vibration bars and a primary-side channel head that provides easy access for robotic tooling to improve plant performance and maintenance. With its placement, Westinghouse will now embark on reactor coolant loop piping installation.

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3. Nuclear milestone. America’s first-ever AP1000 steam generator (the brown cylinder at center) was lifted into place at the V.C. Summer nuclear power plant this January. The steam generator, including the integral reactor coolant pump casings, weighs more than 600 metric tons and is about 24 meters (m) tall and 6 m in diameter. Courtesy: SCE&G

Westinghouse in December placed the second containment vessel ring at Vogtle 3. Other recent milestones at the Vogtle site included placement of the Unit 3 reactor vessel on November 23 and the Unit 4 CA01 structural module on November 21.

The milestones are notable for the two projects, which have suffered delays and cost overruns. Construction at Vogtle began in 2013. Vogtle 3 is now scheduled to start operations in 2019, while Vogtle 4 is expected to be operational in 2020. Construction kicked off at V.C. Summer in 2013, too. Unit 2 is expected to enter operations in 2019, and Unit 3 in 2020.

Westinghouse’s construction of four AP1000 reactors in China, two each at Sanmen in Zhejiang province and Haiyang in Shandong, are reportedly nearing completion, though they too have been beset by delays ranging from three to four years, mostly owing to design changes. While construction kicked off at Sanmen Unit 1 in April 2009, and in September 2009 at Haiyang, all four reactors are slated to be operational by the end of this year.

In January, the China National Nuclear Corp. reported that installation of the fourth and final reactor coolant pump had been completed at Sanmen 2, marking a milestone toward the start of cold commissioning tests. Three weeks later, the China Nuclear Engineering Corp. announced that coolant pumps from the U.S. had reached the construction site at Haiyang.

Sonal Patel is a POWER associate editor.