Installation of the second tier of the reactor building's internal containment has been completed at the Unit- 1 of Akkuyu NPP in Turkey on July 1. The unit is being constructed according to Russian design based on VVER-1200 reactor and is one of the reference projects of Rooppur Nuclear Power Plant in Bangladesh.
The internal containment comprises three tiers and a dome. Second tier is one of the largest structural components of the reactor building. Internal containment is one of the critical components of power unit's safety systems, which prevent release of radioactive materials to the environment.
After installation the structure height of the reactor building increased by 12-meters, from the level of +4.95meters to +16.95 meters. The total weight of the installed structure is 411tons and its diameter exceeds 20 meters. Once the installation of the internal containment is completed, it will undergo a pressurized leakage test.
The Akkuyu NPP will have external containment as well. It is required to protect the reactor, steam generators and other equipment from extreme external hazards.
The double containment of the reactor building is a feature of the innovative Russian nuclear power unit design based on Gen III+ VVER-1200 reactors. Such a sealed containment structure is highly reliable and a significant step towards improvement of safety of nuclear power plants. This kind of nuclear power plants are being constructed in several countries including Bangladesh, Belarus, China, and Egypt among others. ThreeVVER-1200 reactor based power units are successfully functioning in Russia itself.
Construction and installation work are currently being performed at three power units of Akkuyu NPP simultaneously.