The upper part of the inner containment dome (VZO) has been installed at unit 2 of Russia’s Kursk-II NPP. The component weighing 256 tons with a diameter of 36 metres was installed at a height of 51.5 metres increasing the overall height of the reactor building to 61.7 metres. The work was carried out in two stages – on 8 December, the lower part weighing about 220 tons was installed. The work was undertaken by specialists of Trust RosSEM, which is part of Rosatom’s Engineering Division, Atomstroyexport.
Andrey Osharin, First Deputy Director for the Construction of New Units at Kursk explained that the installation requires accuracy that does not allow a deviation of more than 10mm. “Using the experience of similar work on the first power unit, we applied new building solutions and simplified the procedure. For example, the lower dome tier was installed with pre-mounted channels of the containment system. At unit 1, this stage was completed after the dome was lifted, which resulted in difficulties in this process.”
The two domed parts of the inner containment have design differences compared with the underlying tiers: they were enlarged into the ring on the construction site, after which the installation of the finished metal structure was carried out. The underlying tiers were mounted with separate elements and enlarged into the ring on the mounting. Enlargement of both structures was carried out within 120 days - 10 days faster than similar work at unit 1.
“Installation of the dome is a key event in the process,” said Oleg Shperle, vice president of Atomstroyexport and director of the Kursk-II project. “It paves the way for work in the reactor building and provides more comfortable conditions in preparation for the installation of the reactor vessel, steam generators and the main circulation pipeline. The first step will be connecting and launching the polar crane.”.
As soon as both tiers of the domed part of the inner containment are properly connected concreting of the dome will begin, which is expected to be completed in March 2023.
Kursk-II 1&2 are being built according to the VVER-TOI project (standard optimised informatised pressurised water power reactor), which is a development of the VVER-1200 reactor design. Kursk II is intended as a replacement station for the currently operating Kursk NPP, which comprises four RBMK reactors. Unit 1 was closed in 2021 and unit 2 is to close in 2024.
Image: Installation of the upper part of the inner containment dome at unit 2 of Russia’s Kursk-II NPP (courtesy of Rosatom)
