The Volgodonsk Branch of JSC "AEM-technology" (part of the machine-building division of Rosatom - "Atomenergomash") started welding the lower semi-vessel of the reactor for the second Power Unit of the "Rooppur" NPP under construction in the Republic of Bangladesh.
The lower semi-vessel consists of three shells and a bottom, the total weight of the structure is 160 tons. The welding process of parts takes place within 12 days with continuous heating of the weld zone at a temperature of 150-300 degrees. After welding, the lower semi-vessel will be heated to 250 degrees and placed in a gas furnace for heat treatment to restore the mechanical properties of the metal.
After the technical inspection of the welded joints, the internal corrosion-resistant overlay in the weld zones will be applied to the semi-vessel.
In parallel, the upper semi-vessel of the reactor is being manufactured. Now, it is being machined, after which overlay will be applied on the fillet parts of the item.
The reactor is a vertical cylindrical vessel with an elliptical bottom, inside of which the in-core and internals are located. The weight of the VVER-1200 reactor pressure vessel exceeds 330 tons, the height is 12 meters, and the diameter is 4.5 meters. The top of the reactor is tightly closed by a cover with drives of mechanisms and controls and protection of reactors installed on it and nozzles for outputting cables of sensors for in-core monitoring. The cover is mounted to the vessel by means of studs. In the upper part of the vessel, there are nozzles for supplying and removing the coolant, as well as nozzles for emergency supply of the coolant when the circuit is depressurized.