Inner dome installed at Zhangzhou 3

The Hualong One reactor design features a double-layered containment building, the main function of which is to ensure the integrity and leak tightness of the reactor building, and it plays a key role in the containment of radioactive substances.

Following "a series of high-precision manoeuvres including luffing, hook raising, traversing, and adjustments", the steel inner dome for Zhangzhou unit 3's inner containment - measuring 45 metres in diameter and almost 14 metres in height, and weighing more than 370 tonnes - was placed on top of the walls of the double containment structure using a 3,200-tonne crawler crane on 4 February.

_{(Image: CNNC)}

China National Nuclear Corporation (CNNC) said the installation of Zhangzhou 3's inner dome "marks its transition from civil construction to equipment installation. This lays a solid foundation for subsequent installation, commissioning, and grid connection, achieving a 'good start' for the second phase of Zhangzhou Nuclear Power Plant in the new year, and injecting strong momentum into the steady progress of nuclear power construction in China".

China's Ministry of Ecology and Environment issued construction licences for Zhangzhou units 1 and 2 on 9 October 2019 to CNNC-Guodian Zhangzhou Energy Company, the owner of the Zhangzhou nuclear power project, which was created by CNNC (51%) and China Guodian Corporation (49%) in 2011. Construction of Zhangzhou 1 began in October 2019, with that of unit 2 starting in September 2020. Unit 1 entered commercial operation on 1 January 2025 while unit 2 entered commercial operation on 1 January 2026.

_{The Zhangzhou site (Image: CNNC)}

In September 2022, China's State Council approved the construction of two Hualong One units as Phase II - units 3 and 4 - of the Zhangzhou plant. Construction of unit 3 began in February 2024, with that of unit 4 starting in September.

There are proposals for two more units at the plant. Once fully completed, a six-unit Zhangzhou plant would provide more than 60 billion kilowatt-hours of clean energy annually, estimated to meet 75% of the total electricity consumption of Xiamen and Zhangzhou cities in southern Fujian.

"Currently, units 1 and 2 are in commercial operation; units 3 and 4 are under civil construction and installation; and units 5 and 6 are progressing steadily in the preliminary stages," CNNC said.