Inner dome hoisted into place at Lufeng 6

Tuesday, 15 July 2025

The steel dome - measuring 45 metres in diameter and almost 14 metres in height, and weighing about 238 tonnes - was raised some 60 metres above ground level using a crawler crane and lowered into position on top of the walls of the double containment structure. An outer dome will subsequently be installed over the inner one.

"The project construction team accurately predicted the difficulties of hoisting through simulation and deduction of the whole process, and comprehensively used 3D laser simulation and real-scene replication technology, finite element analysis, real-time meteorological monitoring and other technical means to ensure that the dome was successfully hoisted into place in one go," said Zhang Weixiao, the person in charge of the dome hoisting operation.

_{(Image: CGN)}

The main function of the dome is to ensure the integrity and leak tightness of the reactor building, and it plays a key role in the containment of radioactive substances.

China General Nuclear (CGN) said the installation of the dome "marks the successful capping of the reactor building of the Hualong One nuclear power unit, and the project construction officially shifted from the civil construction stage to the equipment installation stage".

The construction of Hualong One reactors as units 5 and 6 at the Lufeng plant was approved by the State Council in April 2022. First concrete for unit 5 was poured on 8 September 2022, with that for unit 6 following on 26 August 2023. Units 5 and 6 are expected to be connected to the grid in 2028 and 2029, respectively.

The proposed construction of four 1250 MWe CAP1000 reactors (units 1-4) at the Lufeng site was approved by China's National Development and Reform Commission in September 2014. However, the construction of units 1 and 2 did not receive State Council approval until 19 August last year. The first safety-related concrete for the nuclear island of unit 1 was poured on 24 February this year. Approval for units 3 and 4 is still pending. The CAP1000 design is the Chinese version of the Westinghouse AP1000.

According to CGN, once all six units are in operation, the Lufeng plant will generate about 52 TWh, which will reduce standard coal consumption by almost 16 million tonnes and reduce carbon dioxide emissions by more than 42 million tonnes.