Rosatom has begun installation of the domed part of the outer containment at unit 1 of the Rooppur NPP under construction in Bangladesh. Work on the assembly and installation of the dome is being carried out by Rosatom’s specialist branch Trest RosSEM (part of Engineering Division ASE). The installation of the lower tier of the dome has already been completed. The large-sized structure, weighing 200 tons and 46.3 metres in diameter, was installed in the design position at a height of 48.8 metres. It was lifted into place by a Liebherr LR 13500 crane (capacity 1350 tons), and took about five hours.
“The outer containment is one of the key localising security systems. This is a reinforced concrete structure that protects the reactor plant from external influences and is able to withstand an earthquake, tsunami or hurricane,” commented Alexei Deriy, Vice President of JSC ASE, Director of the project for the construction of Rooppur NPP.
In addition to the outer containment, the reactor building is protected by an inner containment, which was installed in 2021. The double containment is a distinctive safety feature of the Russian design VVER-1200 reactors.
The Rooppur plant is being built by Rosatom on the eastern bank of the Ganges River in Bangladesh’s Pabna district, about 160 km northwest of Dhaka. It will comprise two VVER-1200 reactors. In November 2011, Russia and Bangladesh signed an intergovernmental agreement on cooperation in the construction of the NPP and in mid-December 2015, a general contract was signed. In early 2017, the Russian government provided Bangladesh with a state loan of $11.38 billion to assist with the construction, which began in 2021.
On 11 November, AEM-Technologies (part Rosatom’s mechanical engineering division Atomenergomash) said its Petrozavodsk branch has completed shipment of a set of hydraulic reservoirs for the passive core flooding system (SPZAZ) of Rooppur unit 2. Each power unit has eight SPZAZ tanks - thick-walled vessels with a volume of 120m3 each, made of stainless steel. The diameter of each is more than 4 metres, with a height 10.5 metres, and weight of 78 tons.
Earlier, the first batch of five tanks was delivered to the port in St Petersburg. After the remaining three were placed in the hold of the ship, it left for Bangladesh through Lake Onega to the Baltic and the Gulf of Finland.
SPZAZ is designed to remove residual heat from the primary coolant of the reactor. During operation, the containers are filled with an aqueous solution of boric acid. If the pressure in the primary circuit drops below a certain level, liquid is automatically supplied to the reactor and the core is cooled. AEM Technologies manufactures the main equipment for the reactor halls of the two Rooppur units. The Petrozavodsk branch has already manufactured and delivered the main circulation pipelines, main circulation pump housings, passive protection systems housing equipment, as well as high-pressure gate valves for equipping the turbine hall.
Image: Installation of the outer dome of unit 1 of the Rooppur NPP under construction in Bangladesh (courtesy of Rosatom)
