The CNEA said workers completed the pouring of concrete over the inner containment dome on 28 May, an operation which took more than 18 hours.
The dome is part of the reactor building’s hermetic protection system, designed to withstand high external and internal pressures and protect against radiation release.
In October 2021, workers lifted into place the reactor pressure vessel for Zhangzhou-1, a 1,126-MW indigenous Hualong One design. The move meant the main nuclear island equipment including the steam generator set had been installed for the plant, a prerequisite for the dome hoisting and main pipeline welding.
There are two Hualong One, or HPR1000, pressurised water reactor units under construction at Zhangzhou. Construction for Zhangzhou-1 began in October 2019 and for Zhangzhou-2 in September 2020.
Owner China National Nuclear Corporation (CNNC) has said Zhangzhou-1 is scheduled to enter commercial operation in 2024 and Zhangzhou-2 in 2025.
The Hualong One is an indigenous, three-loop pressurised water reactor. It incorporates elements of CNNC’s ACP1000 and China General Nuclear’s ACPR1000+ reactor designs.
China has eight other Hualong One units under construction domestically at four sites – two each at Taipingling, Fangchenggang, Changjiang and Sanaocun, also known as Zhejiang Sanao and San’ao.