Metal structures for the inner containment dome of the second unit at the first nuclear power plant (NPP) in Bangladesh were installed at the construction site in Rooppur, according to a statement by the Russian state atomic energy corporation Rosatom.
Rosatom, the equipment supplier and technical consultant for the project, is building two VVER-1200 units of 1,200 MW capacity each at Rooppur located on the eastern bank of the river Ganges.
A Rosatom statement last week said the upper portion of the dome, weighing 194 tonnes and with a diameter of 35.7 meters (m), was placed in its designated position at an elevation of 51.7 m and the construction height has now reached 60.5 m.
The installation of the inner containment dome was carried out in two stages. The lower portion of the dome, weighing 195 tonnes and having a diameter of 42.8 m, was placed in its design position a week earlier, on June 20, 2022, the statement said.
The inner containment is one of the main components of an NPP’s safety system. It not only protects the reactor compartment, but also supports the polar crane used to service the nuclear reactor, the statement added.
“The inner containment (IC) dome installation is one of the milestones of 2022. We performed similar work at power unit 1 last year. Thanks to that, this time the dome pre-assembling activities lasted 56 days less, taking in all 151 days. Once both IC portions have been welded together, the dome concreting will go ahead”, said Rosatom subsidiary ASE Vice President Alexey Deriy, who is also Director of the Rooppur NPP Construction Project.
Concreting of the fifth tier of the inner containment of the reactor building at unit 2 was completed significantly ahead of schedule in December 2021. This marked the completion of construction of the cylindrical part of the inner containment that is one of the main components of the NPP reactor safety system which prevents release of radioactive substances into the environment. The dome of the power unit will be installed on the inner containment.
In June 2020, a truss, or support structure, for the second unit reactor was installed. The support truss is one of the most important elements of the equipment of the reactor pit, and is designed to reliably fasten the reactor vessel and protect it from weight and seismic loads.
The installation of the reactor pressure vessel for unit 1 at Rooppur was completed on October 10, 2021, when it was inaugurated at a formal ceremony attended by Rosatom Director General Alexey Likhachev, which was witnessed via video link by Bangladesh Prime Minister Sheikh Hasina.
Both the latest generation III+ power units at the Rooppur NPP, located 160 km from the capital Dhaka, will be equipped with active as well as passive safety systems, including molten core catchers. According to Rosatom, this evolutionary reactor design fully complies with all the international safety requirements.