A VVER-TOI reactor pressure vessel – the “nuclear heart” – has arrived at the Kursk NPP-2 construction site in Kurchatov, having covered 1800 kilometers. This is the most important equipment of the first power unit. When an NPP is operating, nuclear fuel is placed inside the reactor pressure vessel, and a controlled nuclear reaction takes place with the release of a large amount of heat.

The VVER-TOI reactor pressure vessel weighs 340 tons, its length is 12 meters; it is made of nickel-free steel, which properties are not influenced by radiation and elevated temperatures. The vessel is designed to withstand a pressure of 250 atm, which is 1.4 times higher than the operating one. This is comparable to the pressure rate at a depth of 2.5 km in the ocean.

“The VVER-TOI reactor pressure vessel has its specifics. For instance, as opposed to the VVER-1200 vessel, the number of welding joints in it has been reduced from six to four due to the exclusion of the welding joints in the reactor core. This reduces susceptibility of the joints to ageing through intense radiation exposure and will allow, after 60 years of operation, to extend the service life of the vessel by another 40 years," said Andrei Osharin, First Deputy Director for Engineering Department at Kursk NPP.

“Production sites of the AEM-technology company have become pioneers in manufacturing the equipment for power units with the latest VVER-TOI reactors. Equipment for NPPs is a special product, and any new modification of a standard solution requires an adaptation of the production process for this exact model. But we have successfully risen up to the challenge, at that reducing the time to completion for certain key operations and as always ensuring the highest quality and safety. While manufacturing the reactor for Kursk NPP-2, we applied many modern digital solutions and technologies for the first time. So VVER-TOI can, to a certain extent, be considered a new nuclear “digital product”, with no current analogues in the world,” said Igor Kotov, General Director of AEM-Technologies JSC.

The transport logistics for this super-heavy out-of-gauge cargo was quite complex. From the place of manufacture – the Atommash plant in Volgodonsk – the equipment was transported to the special berth of the Tsimlyansk reservoir, loaded onto a barge and delivered by water to the Semiluki town in Voronezh Oblast. The river route was 1,500 kilometers. For the barge to pass some places, the bottom had to be deepened. Then the product covered another 300 kilometers on a special vehicle to Kurchatov.

 “Along the reactor pressure vessel route from the Semiluki town to the Kursk NPP-2 construction site, works were performed to strengthen the roadbed and 5 bridge structures; about 1.5 km of a bypass road were equiped. The transportation was carried out on a special vehicle in compliance with speed limits,” explained Aleksandr Uvakin, Acting Director of the Kursk NPP.

“Construction and installation works are actively carried out at the construction site for the replacement station. At this point we are starting works on auxiliary and support facilities, continue construction works on the main buildings and structures. The near-term task is to prepare the transportation and handling devices for installation of the reactor. The installation of the reactor pressure vessel at its designed place will launch a new stage of construction – the beginning of thermal and mechanical equipment installation works at Unit 1. This event is scheduled for 2022,” stressed Oleg Shperle, Vice President - Director of the Kursk NPP-2 Construction Project.