On the eve of the Day of Russia, the main event of the year was completed at the site of the Kursk NPP-2 under construction - the PWR-TOI reactor vessel was installed in its final position at the first power unit. This is the most important equipment of the NPP primary circuit. During the operation phase, nuclear fuel is placed inside the vessel and a controlled nuclear reaction proceeds with the release of a large amount of heat.

“Three weeks ahead of schedule, we completed another state task – we mounted the reactor vessel. It was delivered to the site in September 2021. Since that time, a lot of work has been done to prepare a transport and technological scheme for the installation. The installation of the hull in its proper location marks the active phase of the installation of the equipment of the reactor plant. This event counts down to the start of commissioning at the nuclear power plant,” Andrey Osharin, first deputy director for the construction of new units of the Kursk NPP, emphasized the significance of the event.

The installation of the "atomic heart" into the design position was performed in several stages. First, a Liebherr crawler crane brought the reactor vessel to the transport portal of the power unit and loaded it onto a special transport trolley. Then the equipment was moved to the central hall of the reactor compartment and, with the help of a polar crane it  was installed on a support ring in the reactor shaft at a mark of 11.3 meters. The maximum allowable deviation during installation was one tenth of a millimeter – this is the thickness of a razor blade.

The design and manufacture of the PWR-TOI reactor plant and the vessel, in particular, was performed by the domestic industry – enterprises of the Rosatom State Corporation.

“The PWR-TOI reactor vessel has its own characteristics. It differs from the PWR-1200 project not only in a more symmetrical arrangement of nozzles, but also in a smaller number of welds – now there are four of them instead of six, since welded joints in the core area are excluded. This provides an improvement in the performance of the product, given that radiation exposure adversely affects the structure of the weld. This modernization will allow, after 60 years of operation, to extend the service life of the hull twice more by 20 years,” said Alexei Volnov, chief engineer of the Kursk NPP.

“The installation of the reactor pressure vessel is the result of a long-term work of a large team of like-minded people. Having completed it, the construction moved from the active phase of construction work to the phase of heat installation work. Having realized the key task of 2022, we do not stop and continue preparations for welding the main circulation pipelines, the installation of which will begin in the near future,” said Oleg Shperle, vice president and director of the Kursk NPP construction project.

The PWR-TOI reactor vessel weighs 340 tons, its length is 12 meters, it is made of nickel-free steel, which does not change its properties under the influence of radiation and at high temperatures. The product is able to withstand a pressure of 250 atmospheres, which is 1.4 times higher than the working one. This is comparable to the pressure at a depth of 2.5 km in the ocean.

The equipment was manufactured at the Atommash plant in Volgodonsk.