On March 22, 2023, the first concrete date (FCD) of the nuclear island was poured for Unit 4 of Sanmen Nuclear Power Plant Site, a subsidiary of the China National Nuclear Power Co., Ltd of CNNC, marking the beginning of the construction of the Phase II project of Sanmen Nuclear Power Plant.

Sanmen Nuclear Power Unit 4 is the first nuclear power unit to start construction in China after the 20th National Congress of the Communist Party of China and after the National "Two Sessions". (Source: CNNC)