In Volgodonsk Branch of JSC “Mechanical Engineering Division-technology” “Atommash” (a part of machining building subdivision of  ROSATOM - “Atomenergomash”) the welding of circumferential joints on the upper semi-vessel of RPV for Turkish  Akkuyu NPP has been finished.

This is one of the key stages of reactor vessel manufacture.  Upper semi-vessel has been assembled of two shells and a flange. Total mass of the equipment is approximately 180 tons. Specialists has been performing the automatic welding of two circumferential welds on the welding installation for 22 days when continuous heating of the weld area. After welding operation, the areas of semi-vessel welded joints were subjected to heating up to 300 degrees. After that the semi-vessel was transferred to the heating furnace for HT in order to obtain the required mechanical properties of the metal. Heating and holding are performed at maximum temperature of 620 degrees for three days.

After HT the necessary tests of welded joints shall be performed. Subsequently, semi-vessel shall be prepared for applying of the inner corrosion resistant overlay in the areas of welded joints.

“We closely cooperate with the customer representatives and regulatory organizations; regularly conduct joint audits, concerning the issues of equipment manufacturing.  Currently, all works for Turkish NPP are being performed in accordance with the production schedules”, said Rovshan Abbasov, director of the Volgodonsk Branch of JSC “Mechanical Engineering Division-Technology”.

The Reactor is a vertical cylindrical body with elliptic bottom, inside of which the core and the Internals are located. The top reactor is tightly sealed with the cover with drives mechanisms and regulatory and protection bodies of the reactors and nozzles for the cable outlet of in-core monitoring sensors. Fastening of the cover to the vessel is performed with the studs.  In the upper part of the vessel there are nozzles for coolant supply and removal, and also nozzles for emergency coolant supply in case of circuit depressurization.

Akkuyu NPP in Turkey is being built as per updated project with new generation III + power units complying with the highest safety standards. JSC “Atomenergomash” is full range  manufacturer and supplier of equipment of Reactor Plant and Turbine hall for all four NPP Units. Reactors, steam generators, pumping, heat exchange and other equipment that will ensure the reliable and safe NPP operating during the whole operating life shall be manufactured by enterprises of subdivision.