Outer dome in place at third Changjiang unit

Wednesday, 23 October 2024

The dome - measuring 53 metres in diameter, 13 metres in height and weighing about 415 tonnes - was hoisted into place on top of the containment building using a 3200-tonne crane on 18 October. The process of raising the outer dome into position 58.8 metres above the ground took just under 2 hours.

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.

_{(Image: CNNC)}

The steel dome for Changjiang unit 3's inner containment - measuring more than 46 metres in diameter and 23 metres in height - was raised by crane and placed on top of the walls of the double containment structure in February 2023. The inner containment dome has since been concreted.

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, which holds a 51% share in the project. The construction period is expected to be 60 months. Both units are scheduled to be fully operational in early 2027.

_{(Image: CNNC)}

CNNC said the installation of the outer dome of unit 3 "marks the completion of the construction of the main structure of the unit and lays a solid foundation for the subsequent installation, cold test and grid-connected power generation".

The Changjiang nuclear site is already home to two operating CNP-600 pressurised water reactors (PWRs) - Changjiang 1 and 2 - which 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 PWR - also referred to as the Linglong One - is designed for electricity production, heating, steam production or seawater desalination.

_{(Image: CNNC)}

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.

"As a major energy project in Hainan province, the Hainan Changjiang Nuclear Power Phase II Project is an important measure for CNNC to deeply integrate into the construction of Hainan Free Trade Port and actively promote the construction of Hainan Clean Energy Island," CNNC said. "The successful installation of the outer dome of the No.3 nuclear island will further promote the green and low-carbon process of Hainan Free Trade Port and inject strong momentum into the country's active, safe and orderly development of nuclear power and the construction of a new energy system."