The Volgodonsk branch of AEM-Technologies (part of Rosatom’s mechanical engineering division Atomenergomash) said on 19 July that it had assembled six half-shells for the passive core bay system (SPZAZ) tanks for unit 1 of the Akkuyu NPP under construction in Turkey.
The 60mm thick stainless steel shells were assembled into half-shells and the circular seams were welded. Inside each container, specialists will install flooring, which is a prefabricated welded structure from a round bar with a diameter of 4 metres and a mass of 495kg. The decks are placed in the form of a three-level slipway for the safe movement of service personnel inside the tanks.
SPZAZ belongs to the second stage of passive NPP safety systems. The system includes eight hydraulic tanks each with a volume of 120 cubic metres. During operation, an aqueous solution of boric acid is stored in the tanks, heated to 60 degrees Celsius. When the pressure in the primary circuit drops below a certain level, the liquid is automatically supplied to the reactor and the core is cooled.
The weight of the SPZAZ tank is 77 tons, the height is 10.5 metres, and the diameter 4.24 metres. Atommash will manufacture SPZAZ hydraulic tanks for units 1 and 3 of the Akkuyu NPP.
The Akkuyu NPP construction project is being implemented by Akkuyu Nuclear following an intergovernmental agreement signed between Russian and Turkey in 2010. The Akkuyu NPP, with four VVER-1200 units, is being constructed on a build-own-operate basis by Rosatom, with commissioning of the first unit planned for 2023.