Fourth Hualong One under construction at San'ao site

The company said the pouring of first concrete at 08:28 on Tuesday "marks the official start of the main construction of the unit and the full-scale construction phase of the second phase of the project".

On 2 September 2020, the executive meeting of the State Council approved the construction of units 1 and 2 as the first phase of the San'ao plant. China's National Nuclear Safety Administration issued a construction permit for the two units on 30 December that year and first concrete for unit 1 was poured the following day. The first concrete for San'ao 2 was poured on 30 December 2021.

Unit 1 achieved first criticality in February this year and was connected to the grid in March. The reactor was declared to be in commercial operation on 29 April.

Cold functional tests - which are carried out to confirm whether components and systems important to safety are properly installed and ready to operate in a cold condition - were completed at San'ao 2 in October last year. Hot functional tests - which simulate the temperatures and pressures which the reactor systems will be subjected to during normal operation - were completed in April this year. The loading of fuel assemblies into the core of unit 2 was completed last week. The reactor is scheduled to begin supplying electricity in 2027.

The construction of two Hualong Ones as the second phase (units 3 and 4) of the San'ao plant was among plans for 11 reactors approved by China's State Council in August 2024. The first concrete was poured for the nuclear island of unit 3 on 19 December last year. A further two Hualong One units are planned as Phase III (units 5 and 6).

"Overall construction is progressing steadily according to plan," CGN noted.

The San'ao plant is the first nuclear power project in China's Yangtze River Delta region to adopt the Hualong One pressurised water reactor design. Upon completion, the project will provide more than 54 TWh of electricity annually to Zhejiang Province and the Yangtze River Delta region, reducing standard coal consumption by more than 16 million tonnes and carbon dioxide emissions by almost 50 million tonnes annually, CGN noted.

The San'ao project marks the first Chinese nuclear power project involving private capital, with Geely Technology Group taking a 2% stake in the plant. CGN holds 46% of the shares of the project company Cangnan Nuclear Power, with other state-owned enterprises holding the remainder.