In the reactor building of power unit No. 1 of the Kursk NPP-2, the installation of the dome of the inner containment was completed.  The final layer of the inner containment is installed in its regular place.  The work was performed by specialists of Trest RosSEM, which is part of the Rosatom Engineering Division.

The inner containment is the most important device that provides the radiation safety of a nuclear power plant.

“The dome of the inner containment of the reactor building of power unit No. 1 has been completed. The installation of the final layer of the inner containment is a very demanding installation operation that requires high professionalism, since the mounted metal structure weighs 265 tons and requires high installation accuracy - the tolerances are 10 mm.  The diameter of the layer is 27 meters at the bottom.  At the top, it tapers completely to form a sealed dome.  The structure of the reactor building of the first power unit has now reached a height of 61.7 meters,” explained Andrei Osharin, first deputy director for construction of new units at the Kursk NPP.

The installation of the closing tier was preceded by a no less complex installation of the fifth tier weighing 193 tons.  The two domed parts of the inner containment shell have structural differences from the underlying tiers: they were enlarged into a ring on the site, after which the ready-made metal structure was installed.  While the underlying tiers were mounted in separate elements and enlarged into a ring on the mounting horizon.

The installation of the layers of the dome part of the inner containment was made by one of the most powerful crawler cranes in the world - Liebherr-11 350 with a lifting capacity of up to 1350 tons.  The crane was specially delivered to the construction site of the Kursk NPP-2 for this task.

Completion of the installation of the inner containment dome part opens a new front for work in the reactor building - it allows one to start operations on connecting and starting up the polar crane, installing the reactor vessel, steam generator, main circulation pipeline, as well as to carry out work on finishing the premises, coating structures inside the containment and create the "Clean installation" zone, which is an essential condition for starting the installation of the reactor vessel.

“The installation of the dome is a milestone event in the construction process of the Kursk NPP-2,” noted Oleg Shperle, vice president of Atomstroyexport, project director for the construction of the Kursk NPP-2.  “It was fundamental to us that the completion of the installation of the inner containment takes place exactly in 2021, because the closure of the thermal circuit created comfortable conditions for working in the central hall of the reactor building in winter.”

The builders will start concreting the dome of the inner containment in March next year.

The construction of the inner containment for power unit No. 1 took two years - the installation of its first layer was started in December 2019.