In the construction area of the reactor compartment of the 2nd power unit of the AKKUYU Nuclear Power Plant (NGS), the construction of the reactor shaft continues. The support and thrust beams, the main elements of the shaft structure, the dry reactor shield and the thermal insulation of the cylindrical part of the reactor pressure vessel were installed in the design position.
The assembly of the support beam, one of the elements of the reactor shaft in the form of a welded metal structure designed for reliable fastening of the reactor vessel to the concrete shaft, was carried out with the help of the Liebherr LR 13000 heavy crawler crane. The support beam, with a diameter of more than 9 meters and a weight of 88 tons, fulfills the functions of protecting the reactor from weight and seismic loads. While the installation process of the support beam takes 1 hours for 8 working day, work on consolidation, pouring concrete into the cavities and construction of the measuring channels continues.
The assembly process of the thrust beam, which is a welded metal construction with a diameter of more than 7 meters and a weight of 27 tons, designed to fix the reactor pressure vessel to the concrete shaft, was done before the pre-assembly and welding of the construction elements and took several hours.
Akkuyu Nuclear AŞ First Deputy General Manager and NGS Construction Director Sergei Butckikh stated the following on the subject: “The installation of support and thrust beams is among the most important events of 2021 in the construction of the second power unit of Akkuyu NPP. The successful completion of the assembly offers the possibility to continue the construction work of the reactor shaft. The installation of such large-sized constructions is one of the complex types of assembly. Because the allowable deviation in the reactor shaft is 2 mm in total. Experience gained in similar work on the first power unit allowed the experts who installed the beams to complete the work earlier than planned.”
Previously, the dry reactor guard, a 9-ton safety and biological protection element, was installed in the reactor building of the second power unit, which ensures the safe operation of the nuclear power plant in emergency situations, including a 142-magnitude earthquake. The dry reactor protector ensures the sustainable operation of the ionizing cells, which are the special measuring channels required for the measurement of the reactor capacity.
Before the assembly of the reactor shaft components, the installation of the reactor pressure vessel, the heart of the nuclear power unit, was carried out. Just prior to the installation of the reactor pressure vessel, construction workers had to assemble the supporting ring that would bear the main weight load of the pressure vessel.
The equipment of the reactor pressure vessel is designed to fix the reactor during operation. This equipment also fulfills the biological and thermal protection function against neutron flow in the reactor core.