While construction works at the Rooppur Nuclear Power Plant site is progressing as scheduled, manufacturing and testing of various equipment for the plant is going on in full swing in Russia, an official familiar with the matter said.
The power plant with a capacity of 2400 megawatt is being implemented in Rooppur of Pabna district by a subsidiary of Russia’s State Atomic Energy Corporation, Rosatom.
According to Rosatom officials, recently as part of technical control, hydraulic tests of Reactor Pressure Vessel (RPV) and the first steam generator for the unit-1 of Rooppur Nuclear Power Plant have been completed in the Volgodonsk Branch of “AEM-technology” “Atommash” in Russia.
A reactor pressure vessel (RPV) in a nuclear power plant is the pressure vessel containing the nuclear reactor coolant, core shroud and the reactor core. On the other hand, the steam generator is a heat exchanger which is 14 meters in length, more than 4m in diameter and weighs 350 tons. The Unit-1 of Rooppur NPP will have four such steam generators.
The tests confirmed the strength and tightness of base metal as well as of welding joints of the both, which belong to items of first safety class in a nuclear power plant.
After having been fully sealed, the 11-meter-tall RPV was tested in an underground Caisson. The RPV was filled with distilled water, which was heated up to 100 degrees Celsius and a maximum pressure of 24.5 MPa (1.4 times higher than the working pressure) was built up for testing.
Similarly, in other testing all holes of the steam generator were closed with special blind covers. Primary and secondary circuits of the steam generator were filled with distilled water. The primary circuit was tested at a pressure of 24.5 MPa and water temperature of 350 degrees Celsius. The secondary circuit was tested at a pressure of 11.45 MPa and water temperature of 300 degrees Celsius. In both cases the pressure was 1.4 times higher than the operating pressure.
Earlier in the same factory, welding of steam generator bottom was completed. Before welding steam generator vessel was fed with SG tubes. The automatic welding of the bottoms was performed at a temperature of 120-190 degrees for 5 days. The welding of two joints uses 700 kgs of wire and 900 kgs of flux.
Meanwhile, “AEM-technology” “Petrozavodskmash” completed assembly and welding of ring weld joints of four main coolant pumps for unit-1 of Rooppur NPP).
Coolant Pumps (RCP) at a nuclear power plant helps coolant circulation from the reactor to the steam generators and operates under a coolant pressure of 160 atmospheres and at temperature of 300 degrees Celsius. Each unit of Rooppur NPP will have four such coolant pumps.
It is mentionable that 1200MW unit of electricity from the first nuclear plant will be added to the national grid by 2023. The second with the same amount of power will be launched by 2024.