Construction starts on second phase of Sanmen plant

29 June 2022

The first safety-related concrete has been poured for the nuclear island of unit 3 at the Sanmen nuclear power plant, China National Nuclear Corporation (CNNC) has announced. It marks the official start of construction of the first of two CAP1000 pressurised water reactors planned as Phase II of the site in China's Zhejiang province.

First concrete is poured for Sanmen unit 3 (Image: CNNC)

A ceremony was held on 28 June to mark the pouring of first concrete for Sanmen 3. It was attended by provincial officials and representatives from CNNC, the Ministry of Ecology and Environment, the National Energy Administration and the National Nuclear Safety Administration.

The construction of two new reactors at each of the Sanmen, Haiyang and Lufeng nuclear power plant sites in China was approved by the country's State Council on 20 April this year. The approvals are for Sanmen units 3 and 4, Haiyang 3 and 4 and units 5 and 6 of the Lufeng plant.

The Sanmen and Haiyang plants are already home to two Westinghouse AP1000 units each, and two CAP1000 units - the Chinese version of the AP1000 - were approved for Phase II (units 3 and 4) of each plant.

In May, CNNC signed contracts for the civil construction of the nuclear islands and installation engineering for the planned second phases of the Sanmen and Haiyang nuclear power plants. China Nuclear Industry 22 Construction Company was contracted to carry out the civil construction of the Sanmen Phase II nuclear island, while China Nuclear Industry 24 Construction Company will conduct the civil construction of the Haiyang Phase II nuclear island. Meanwhile, China Nuclear Industry Fifth Construction Company (CNI5) has been contracted to undertake the nuclear island installation work at all four units.

Phase I of the Sanmen plant began operating in 2018. Sanmen 1 was the world's first AP1000 to start up, achieving first criticality - a sustained chain reaction - on 22 June and grid connection on 2 July. It reached full power operation for the first time on 14 August and entered commercial operation on 21 September. Sanmen 2 attained first criticality on 17 August and was connected to the grid on 24 August. The reactor entered commercial operation on 5 November. The units have since generated more than 60 billion kilowatt hours, CNNC noted.

After the two units of Phase II are fully operational, the Sanmen plant is expected to have an installed capacity of 5 million kilowatts, and to generate 40 billion kilowatt hours each year, the company said. This, it noted, is equivalent to reducing 30 million tonnes of carbon dioxide emissions. CNNC added that the additional nuclear capacity will help "optimise the industrial structure and energy mix in Zhejiang and is of great significance for the province's shift to green and low-carbon energy, as well as its high-quality economic and social development."

Researched and written by World Nuclear News