Sanmen-1, in China's Zhejiang province, the world's first nuclear generating unit of the Westinghouse AP1000 design, successfully reached first criticality Thursday, project operator State Nuclear Power Technology Corporation said.
The successful criticality is a milestone in the construction of the 1,200-MW Sanmen-1, which is now a step closer to entering commercial operation, SNPTC said in a statement. First criticality represents the start of a self-sustaining fission reaction in the core of a reactor. The step will be followed closely by the production of power and connection to the grid, reactor designer Westinghouse said in a separate statement Thursday.
In September 2007, US-based Westinghouse announced that it had won authorization to construct four AP1000 units in China, including two at Sanmen and two at Haiyang.
Sanmen-1 and Haiyang-1 are the first AP1000 units to be built in the world. China acquired the rights to build its own version of the AP1000 when it agreed to purchase four units from Westinghouse for the Sanmen and Haiyang plants.
Two AP1000 reactors are under construction in the US, at Georgia Power's Vogtle plant in Waynesboro, Georgia. They have experienced delays and cost overruns as a result of first-of-a-kind design, licensing, procurement and construction issues.
The units are scheduled to be operating commercially in 2021 and 2022, respectively.
The delays and cost-overruns of the Vogtle nuclear plant expansion and the now-canceled effort to build two similar units at South Carolina Electric & Gas's Summer station resulted in the bankruptcy reorganization filing of Westinghouse in March 2017. The US Bankruptcy Court for the Southern District of New York in March approved the company's exit from bankruptcy later this year under new owner Brookfield Business Partners, a real estate and industrial holding company.
Georgia Power officials have said they are benefitting from lessons learned during the construction, testing and start-up of the Sanmen and Haiyang units.
"This milestone cements American technology as the most advanced reactor design commercially available," Daniel Lipman, vice president of supplier and international programs at the Nuclear Energy Institute, said in a statement.
The start-up dates for Sanmen-1 and -2 had been postponed several times in the past years due to delays caused by design changes and problems with components, including reactor coolant pumps shipped from the US.
SNPTC said Thursday that Chinese regulators gave permission for the start of fuel loading at Haiyang-1, the second AP1000 in China to be built.
The country has more than 30 GW of nuclear capacity under construction and plans to have 58 GW of installed capacity operational by 2020 as it seeks to increase carbon-free power generation and fight pollution.
The construction of reactors from suppliers from France, Russia and the US are part of China's plan to build only nuclear units with advanced designs following the 2011 Fukushima I nuclear accident in Japan. Russian-designed units have been operating in China since 2007, and a 1,600-MW reactor designed by French utility EDF's Framatome business recorded first criticality at the Taishan site in China earlier this month.
