The Volgodonsk branch of Russia’s AEM-Technologies (part of Rosatom’s Mechanical engineering division Atomenergomash) said on 11 May that it had shipped a set of steam generators (SGs) for unit 1 of Kursk-II NPP. The SGs, weighing 355 tons each, will travel 1500 km down the Don river to Voronezh. Then they will be loaded onto a railway conveyor and delivered by rail to the NPP site. Modifications of the equipment for the VVER-TOI reactor at Kursk requires a new design, in which there is no steam collector in the upper part of the SG. Steam comes out of one pipe, which is directly connected to the steam line. The length of the steam generator is increased by one metre to 15 metres, the diameter is more than 4 metres. In the middle part there are collectors for supplying and removing the coolant, where the ends of 11,000 heat exchange tubes - coils are fixed. The diameter of the pipes is 16 mm, their length is 11-17 metres.
The steam generator PGV-1000MKO for the VVER-TOI project has an increased steam capacity and thermal power - 1652 t/h, compared with 1602 t/h for the PGV-1000MKP used with VVER-1200 reactors. The rated thermal power of the PGV-1000MKO steam generator is 828MW, and for the PGV-1000MKP, 803MW. The VVER-TOI project also has a new layout of equipment. The steam generators are arranged in two rows, two steam generators in a row. In previous projects, steam generators were located tangentially around the reactor.
According to Igor Kotov, General Director of AEM-Technologies, the Kursk-II project is important for the further development of Russian technologies for VVER reactors. “AEM-Technologies is the largest manufacturer of equipment of this type, and the release of the VVER-TOI model is a kind of challenge for us, the opportunity to show our ability to quickly, at a high level, adapt production processes to meet new challenges,” he said. “Despite the quarantine restrictions, we have successfully coped with the release of the first set of equipment for the new VVER-TOI type of domestic reactor."
Kursk-II is a replacement station for the current Kursk nuclear plant. Commissioning of the first two units with the new design VVER-TOI reactors will be synchronised with the decommissioning of the RBMK reactors at Kursk 1&2 of the operating plant.
On 12 May, the Petrozavodskmash branch of AEM-Technologies said it had manufactured and shipped eight sets of embedded parts for fastening the hydraulic tanks of the passive core bay system (SPZAZ) for unit 1 of Kursk-II. Embedded parts are metal rings with a diameter of about 5 metres and weighing more than 8 tons. The total weight of the manufactured equipment is about 72 tons. Transportation of products is by road over a distance of more than 2,000 kilometres.
These metal elements are made of sheet, round or shaped steel, which are concreted into the foundations and floors of NPP buildings for subsequent connection of equipment fastening elements with them.
SPZAZ hydraulic tanks are thick-walled stainless steel vessels with a volume of 120 cubic metres each. At the station, they will be filled with an aqueous solution of boric acid. When the pressure in the primary circuit drops below a certain level, the valves are triggered and saturated steam from the main circulation pipeline enters the tank of the SPZAZ, which leads to the drainage of water from the tank into the reactor and cooling of the core. There are eight SPZAZ tanks for each power unit.
Image: A new type of steam generator has been shipped to Kursk-2 (Photo: Atomenergomash)