The inner containment dome has been installed at unit 5 of the Lufeng nuclear power plant in China's Guangdong province. It is the first of two HPR1000 (Hualong One) under construction at the site, where four CAP1000s are also planned.

The dome is hoisted into place (Image: CGN)

The steel dome - measuring 45 metres in diameter and almost 14 metres in height, and weighing about 238 tonnes - was raised using 1600-tonne crawler crane and placed on top of the walls of the double containment structure. An outer dome will subsequently be installed over the inner one.

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

The hoisting process for the inner dome, which began at 8.08am on 29 April, was completed in 1 hour and 8 minutes, China General Nuclear (CGN) announced.

The dome atop of the containment building (Image: CGN)

CGN said the milestone "marks the full transition of another Hualong One nuclear power unit 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 last year. 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 the National Development and Reform Commission in September 2014. However, their construction has yet to receive State Council approval. 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.