Atommash (a part of the machine-building division of Rosatom-Atomenergomash) finished welding of circumferential welds on upper reactor semi-vessel for Unit No.3 of Xudapu NPP under construction.
It took 4,700 kg of flux and 3,300 kg of wire to weld the circumferential welds. The work has been carried out for 25 days with continuous heating at 150-170 degrees Celsius in welded joints area. After that, the item was heated up to 300 degrees and moved to a furnace for heat treatment to obtain the required mechanical properties of the metal. The process of heating and holding is carried out at a maximum temperature of 620 degrees for three days.
After heat treatment, the specialists carried out machining and technical inspections: visual and dimensional, ultrasonic, magnetic particle flaw detection, and radiographic examination of welded joints. At a later stage, the specialists of the factory will perform a corrosion-resistant overlay on the inner part of the semi-vessel.
A reactor is an item of the safety class 1, and it is a vertical cylindrical vessel with an elliptical bottom. There is a core and internals inside the item. The vessel is sealed with a top head with drives of mechanisms and control and protection units installed on it, nozzles for outputting cables of in-reactor control sensors.
For units No. 3 and No. 4 of Xudapu NPP, Atommash will manufacture two reactor vessels with internals, a top head and an upper unit, and two sets of steam generators.
Xudapu NPP is located in Liaoning Province, China. Power units No. 3 and No. 4 belong to the “NPS-2006” project and comply with modern IAEA safety requirements. The Engineering Division of Rosatom carries out the design and construction of the facility. Commissioning of power units is scheduled for 2027 and 2028, respectively.