concluded that certification of the AP1000 should be delayed until the original and current "unanswered safety questions" raised by the AP1000 Oversight Group are resolved. In 2012, Ellen Vancko, from the Union of Concerned Scientists, said that "the Westinghouse AP1000 has a weaker containment, less redundancy in safety systems, and fewer safety features than current reactors". In response to Ms. Vancko's concerns, climate policies author and retired nuclear engineer Zvi J. Doron, replied that the AP1000's safety is enhanced by fewer active components, not compromised as Ms. Vancko suggests. As in direct contrast to currently operating reactors, the AP1000 has been designed around the concept of passive nuclear safety. In October 2013, Li Yulun, a former vice-president of China National Nuclear Corporation (CNNC), raised concerns over the safety standards of the delayed AP1000 third-generation nuclear power plant being built in Sanmen, due to the constantly changing, and consequently untested, design. Citing a lack of operating history, he also questioned the manufacturer's assertion that the AP1000 reactor's "primary system canned motor pumps" were "maintenance-free" over 60 years, the assumed life of the reactor and noted that the expansion from 600 to 1,000 megawatts has not yet been commercially proven. Chinese design extensions In 2008 and 2009, Westinghouse made agreements to work with the Chinese State Nuclear Power Technology Corporation (SNPTC) and other institutes to develop a larger design, the CAP1400 of 1,400 MWe capacity, possibly followed by a 1,700 MWe design. China will own the patent rights for these larger designs. Exporting the new larger units may be possible with Westinghouse's cooperation. In September 2014, the Chinese nuclear regulator approved the design safety analysis following a 17-month review. In May 2015 the CAP1400 design passed an International Atomic Energy Agency's Generic Reactor Safety Review. In December 2009, a Chinese joint venture was set up to build an initial CAP1400 near the HTR-PM at Shidao Bay Nuclear Power Plant. In 2015, site preparation started, and approval to progress was expected by the end of the year. In March 2017, the first CAP1400 reactor pressure vessel passed pressure tests. Equipment for the CAP1400 is being manufactured, and as of 2020 preliminary construction is underway. In February 2019, the Shanghai Nuclear Engineering Research & Design Institute announced that it had begun the conceptual design process for the CAP1700. Construction plans or potential operators China Four AP1000 reactors have been constructed in China, two at