The Volgodonsk branch of AEM-Technologies (part of Rosatom’s mechanical engineering division - Atomenergomash) has begun to manufacture containers for the passive core bay system (SPZAZ) for unit 1 of the Akkuyu NPP under construction in Turkey, Atommash said on 24 March. Atommash will manufacture SPZAZ hydraulic tanks for Akkuyu units 1&3. Each tank consists of three shells and two bottoms. The shells are made of 60 mm thick stainless steel sheet and 24 shells are needed for the set of SPZAZ tanks. Some of the blanks have already passed initial inspection and the heads and shells are being machined using turning-boring machines and horizontal boring machining centres. The assembly of fittings has started on the bottom of the hydraulic tanks.
The passive core bay system is the second stage of the NPP passive safety system, which includes eight hydraulic tanks each with a volume of 120 cubic metres. During plant operation, an aqueous solution of boric acid is stored in the tanks, heated to a temperature of about 60 degrees. If 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 Akkuyu NPP, the first in Turkey, is being implemented by Akkuyu Nuclear following an intergovernmental agreement signed between Russian and Turkey in 2010. The plant 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. The design and construction is carried out by Rosatom’s Engineering Division and Atomenergomash is supplier of equipment for the reactor plant and the turbine hall for all four units.