Changjiang 3 containment takes shape

Just days after the outer dome was installed at Zhangzhou unit 1 - also a Hualong One unit - CNNC installed the inner dome at Changjiang 3.

The steel dome - with a diameter of 46.8 metres, a height of 23.4 metres and a total lifting weight of 518 tonnes - was hoisted into place on top of the containment building walls, at a height of about 45 metres, using a 3200-tonne crawler crane.

The inner dome at its on-site assembly point (Image: CNNC)

The company said the successful hoisting of Changjiang 3's inner dome on 21 February marked "an important milestone node in the construction of nuclear power projects, marking the transition of unit 3 of the Hainan Changjiang Nuclear Power Plant from the peak of civil construction to the installation stage".

The main function of the double-layered containment building 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 Huaneng, which holds a 51% share in the project, noted that the assembly of Changjiang 3's inner dome adopts work platforms and customised hanging cage measures, breaking the traditional mode of constructing scaffolding platforms, "creating a precedent in the industry for 'zero scaffolding' to complete the assembly of steel-lined domes and the construction of installation items".

The dome is moved by crane from its assembly point towards the reactor building (Image: China Huaneng)

First concrete was poured for the base slab of unit 3's nuclear island in March 2021, with that of unit 4 being poured in the December of that year. Changjiang Phase II - units 3 and 4 - represents a total estimated investment of CNY40 billion (USD6.4 billion), according to China Huaneng. The construction period is expected to be 60 months.

The Changjiang nuclear site is already home to two operating CNP-600 pressurised water reactors - Changjiang 1 and 2 - which are operated by Hainan Nuclear Power Company and entered commercial operation in 2015 and 2016, respectively. In 2021, CNNC also began construction of a demonstration ACP100 small modular reactor at the site. The multi-purpose 125 MWe pressurised water reactor - also referred to as the Linglong One - is designed for electricity production, heating, steam production or seawater desalination.

The island province of Hainan is China's southernmost point. Energy policies published in 2019 by Hainan Province Development and Reform Commission specify that nuclear power will become the primary source of electricity for the island, which has a population of close to 10 million.