Containment walls in place at Sanmen 3

The steel containment shell consists of six modules, namely the bottom head, four ring cylinder modules and the top head.

On 28 July, the fourth ring of the containment shell - with an inner diameter of about 40 metres, a height of about 8 metres and weighing about 749 tonnes - was hoisted into place in an operation lasting two hours.

China National Nuclear Corporation subsidiary Sanmen Nuclear Powder Company said the installation of the fourth ring "lays a solid foundation for the milestone of the top head of the containment shell of unit 3".

The construction of two new reactors at each of the Sanmen, Haiyang and Lufeng sites in China was approved by China's State Council in April 2021. The approvals were 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 were approved for Phase II (units 3 and 4) of each plant.

The CAP1000 reactor design - the Chinese version of the AP1000 - uses modular construction techniques, enabling large structural modules to be built at factories and then installed at the site. This means that more construction activities can take place at the same time, reducing the time taken to build a plant as well as offering economic and quality control benefits.

The first safety-related concrete was poured for the nuclear island of Sanmen 3 on 28 June 2022, marking the official start of its construction. The first concrete for that of unit 4 was poured on 22 March last year. The units are expected to be connected to the grid in 2027 and 2028, respectively.