BEIJING--November 16, 2012--Researched by Industrial Info Resources China (Beijing, China)--The welding of Ring A in the main coolant pipeline for Unit 1 of China National Nuclear Corporation's (CNNC) (Beijing) Sanmen Nuclear Power Station, the first AP1000 nuclear power unit in the world, kicked off recently. This means that the unit has entered the main system's overall erection stage, according to an announcement from State Nuclear Power Technology Corporation Limited (SNPTC) (Beijing), the technical general contractor of the project, on November 9, 2012.