Rosatom began concreting of the turbine building foundation at unit 4 of the Akkuyu NPP under construction in Turkey, project company Akkuyu Nuclear said on 27 May. To ensure maximum strength, 17,500 cubic metres of concrete and 3,500 tons of reinforcement will be placed in the foundation slab construct. The height of the concreting will be seven metres. The foundation plate of the building, which will house the turbine unit, consists of 12 zones, known as "captures". Some 680 cubic metres of concrete will be laid in the first block, after which the installation of the cooling system for the turbogenerator set will be carried out involving enlarged pipelines with a diameter of three metres.
The start of concreting was preceded by work on the preparation of the pit, the formation of the concrete base of the foundation with a volume of 38,000 cubic metres, the installation of waterproofing and reinforcement of the foundation slab. Altogether 450 workers and specialists are involved in the concreting work, the work is being carried out in two shifts. The total area of ??the foundation slab of the turbine building, one of the most important buildings at unit 4, is almost 6,000 square metres.:
“The foundation under the turbine plant is a complex building structure capable of accepting and evenly distributing the loads that occur during the operation of the turbine,” explained Anastasia Zoteeva, General Director of JSC Akkuyu Nuclear. “The construction of the foundation will be carried out in stages, and each individual stage is subject to increased requirements for the quality of concrete. Like all technological solutions used in the construction of Akkuyu NPP, the process of concreting the foundation slab for the unit 4 turbine building will be carried out in accordance with International Atomic Energy Agency (IAEA) safety standards, the requirements of the legislation of the Republic of Turkey and the modern requirements of the global nuclear community.”
After the concrete reaches its design strength, a special commission, including representatives of the Turkish Nuclear Regulatory Agency (NDK) and an independent inspection organisation, will check the quality of the concrete, and the foundation slab will then be considered completed.
The turbine building houses systems and equipment related to power output: a turbine plant, a deaerator (a device for purifying water from gas impurities), feed pumps and auxiliary equipment. The turbine compartment is part of the second circuit, here the thermal energy of water vapor is converted into rotational energy, and then, in the generator, into electrical energy.
In October 2021, Akkuyu Nuclear received a licence for the construction of unit 4. Construction and installation work is now being carried out simultaneously at the construction sites of all four power units of the future Akkuyu NPP. In parallel with the construction of power units, general-purpose buildings and auxiliary facilities necessary for the operation of the nuclear power plant are being erected.
Rosatom is building four VVER-1200 reactors at the site, under a build-own-operate model. Construction of the first unit began in 2018, with start-up planned for 2023. The 4800MWe plant when completed is expected to meet about 10% of Turkey's electricity needs.
Image: Concreting of turbine building foundation which has begun at Akkuyu 4 (courtesy of Akkuyu Nuclear)