[4] Announcement of the project start came roughly twelve months after Westinghouse won a bidding contest over other companies.

The contract for the new plant involved The Shaw Group (now Chicago Bridge and Iron), a minority shareholder in Westinghouse.

[9] Construction of Sanmen Unit 1 began on 19 April 2009, as the first 5,200 m3 of concrete were poured for the foundation, in a ceremony attended by State Nuclear Power Technology Corporation (SNPTC) chair Wang Binghua and Westinghouse CEO Aris Candris.

[12] In June 2014, China First Heavy Industries completed the first domestically produced AP1000 reactor pressure vessel for the second AP1000 unit.

[15][16] In January 2017 China National Nuclear Corporation (CNNC) announced that the final reactor coolant pump had been installed with start of operations still foreseen for 2017.

[17] As of March 2018[update], Sanmen 1 had completed pre-fuelling safety checks but was not expected to be connected to the grid until the fall of 2018 at the earliest.