Inner dome completed at Zhangzhou unit 1

31 May 2022

The concreting has been completed of the inner containment dome of unit 1 at the Zhangzhou nuclear power plant in China's Fujian province, China National Nuclear Corporation (CNNC) affiliate China Nuclear Industry 24 Construction Company (CNI24) has announced. Zhangzhou unit 1, the first of two Hualong One units at the site, is scheduled to enter commercial operation in 2024.

Concreting of the inner dome at Zhangzhou 1 (Image: CNI24)

The steel dome for the inner containment - measuring 45 metres in diameter and almost 14 metres in height, and weighing about 260 tonnes - was raised by crane and placed on top of the walls of the double containment structure in October 2021. An outer dome will subsequently be installed over the inner one. The main function of the 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.

CNI24 has now announced that the pouring of concrete on the inner dome was completed on 28 May following an operation lasting 18 hours and 40 minutes.

The company noted the inner dome now has a maximum radius of about 24.5 metres, the maximum wall thickness is about 2 metres, and the other wall thicknesses are about 1 metre. Some 819 tonnes of steel reinforcement have been used in its construction. The total volume of concrete poured on the inner dome was about 4013 cubic metres.

"The completion of this node marks the perfect conclusion of the civil construction of the inner containment shell of unit 1, and the prestressed construction has the prerequisites, laying a solid foundation for the realisation of the project's scheduled total construction period target," CNI24 said.

China's Ministry of Ecology and Environment issued construction licences for Zhangzhou units 1 and 2 on 9 October 2019 to CNNC-Guodian Zhangzhou Energy Company, the owner of the Zhangzhou nuclear power project which was created by CNNC (51%) and China Guodian Corporation (49%) in 2011. The licences are valid for 10 years. Construction of unit 1 began one week after the issuance of the construction licence, with that of unit 2 starting in September 2020. The units are scheduled to enter commercial operation in 2024 and 2025, respectively.

Researched and written by World Nuclear News