Assembly and welding of spherical casings of reactor coolant pumps (RCP), and local heat treatment of bottom weld of one of the steam generators for Unit-1 of Rooppur Nuclear Power Plant have been completed in Russia.
Assembly and welding of spherical casings of reactor coolant pumps (RCP) were done at “AEM-technology” “Petrozavodskmash”. Weld joints successfully passed all necessary tests.
The RCP casings are now subject to heat treatment at a temperature of up to 640 degrees Centigrade, in a furnace for 7-8 hours. Rooppur NPP Unit-1 will have four RCP spherical casings.
On the other hand, at ‘AEM-technology’ ‘Atommash’ bottom part was welded to the steam generator vessel before the local heat treatment of weld joint, which is a mandatory operation to relieve stress in the welded joint. The volume heat treatment in the furnace is not possible due to the thin-walled stainless SG tubes installed inside the vessel. Local heat treatment includes not only gradual heating of the weld, but also gradual cooling of the joint. The entire process takes one and a half to two days.
Steam Generator will now undergo test operations: evacuation and helium tests, as well as eddy current test of SG tubes. Each unit of Rooppur NPP will have four steam generators.
“AEM-technology” is a part of “Atomenergomash” - machine-building division of ROSATOM, Russia’s state atomic energy corporation. It has two branches “AEM-technology” “Petrozavodskmash” in Petrozavodsk and “AEM-technology” “Atommash” in Volgodonsk.
Atomenergomash is a single-source supplier of all the equipment of the Rooppur NPP reactor compartment and a significant part of the turbine hall equipment.
The Rooppur NPP is designed and built according to the Russian project. The plant will have two power units, each of 1200 MW capacity and equipped with 3+ generation VVER-1200 reactor.