Welding of two shells of the upper semi-vessel at circumference has been completed at the Volgadonsk Branch of AEM Technology Atomash in Russia recently, said Rosatom, the Russian contractor of the RNPP, according to a statement released Wednesday. 

The process took 25 days and was conducted at a welding stand at a temperature of 150-300 degrees. A total of 4,027 kilograms of flux and 3,057 kilograms of wire of 4 mm diameter were used for welding, it noted.

After welding operation, it was moved to a furnace for heat treatment, where it is to be heated at a temperature of up to 270 degrees Celsius for 4 days. The next step in manufacturing is welding of shells and the head of the lower semi-vessel.

The reactor represents a vertical cylindrical body with an elliptical head, containing the Core and the Internals, said the Rosatom.

On top, it is sealed with a cover with drive mechanisms and regulating mechanism installed on it. In the upper part of the vessel, there are nozzles for the coolant input and output, as well as nozzles for emergency supply of the coolant if the circuit is depressurized, it added.

The Rooppur NPP is being constructed following Russian design .The plant will consist of two Power Units each with a capacity of 1200 MW. Each of the Units to host a generation 3+ VVER 1200 reactors.

AEM-technology is a part of Atomenergomash- an engineering division of the Russia’s state atomic energy corporation Rosatom.