The hemispherical structure - with a diameter of 44 metres and a height of 22 metres - was put in place on top of the containment building in a process lasting just over three-and-a-half hours. The dome hoisting included the steel lining structure and support cage, all penetrations, reinforcement plates, internal steel structures, equipment supports and hangers, spray systems, lighting systems, hydrogen removal devices, heat exchanger equipment, detection equipment and other equipment, with a total weight of 655 tonnes.
The assemble dome structure prior to its hoisting (Image: CNNC)
"Unlike the traditional installation of the dome in two stages, the one-stage lifting technology significantly streamlines the process and reduces the time of this work," said Alexei Bannik, Vice President for Projects in China and Advanced Projects of JSC Atomstroyexport. "The dome pre-assembled on the ground was lifted by crane on the reactor building."
In June 2018, Russia and China signed four agreements, including for the construction of two VVER-1200 reactors at the new Xudabao (also known as Xudapu) site in Liaoning province. Agreements signed in June 2019 included a general contract for the construction of Xudabao units 3 and 4, as well as a contract for the supply of nuclear fuel. Rosatom is designing the nuclear island, supplying key equipment, as well as providing field supervision, installation supervision, and commissioning services for the supplied equipment. Turbine generators and balance of plant will be supplied by China.
The dome is lifted during the hoisting process (Image: CNNC)
Construction of Xudabao unit 3 began in July 2021, with that of unit 4 starting in May 2022. The dome of unit 3 was installed in July last year, using the one-stage lifting technique for the first time
Following the installation of the dome on unit 4, CNNC said: "Xudabao nuclear power units 3 and 4, a national key energy project, have all entered the equipment installation stage, laying the foundation for further high-quality and steady advancement of project construction."
The two units - scheduled to be commissioned in 2027 and 2028, respectively - are expected to generate more than 18 billion kWh of electricity per year, equivalent to saving about 6.4 million tonnes of coal and reducing carbon dioxide emissions by about 18.9 million tonnes per year.
Units 3 and 4 at the Xudaba site (Image: CNNC)
Two CAP1000 reactors - the Chinese version of the Westinghouse AP1000 - are planned for units 1 and 2 of the Xudabao plant. Construction of unit 1 began in November 2023.
The Xudabao plant is owned by Liaoning Nuclear Power Company Limited, a joint venture between CNNC (70%), Datang International Power Generation Company (20%) and State Development and Investment Corporation (10%).
