Leningradskaya nuclear power plant (NPP-2)

The safety system configuration of NPP-2 exceeds all others known to date. All constructors participating in the project meet unprecedented safety and quality requirements.

The most difficult from the technical point structures are: cooling towers and nuclear islands buildings of Electric Power Units №1 and №2, constructed by JSC «Metrostroy». The scale of construction requires the use of a large number of modern materials and equipment.

Each stage of the project of any structure passes a multi-level control.  


 
The cooling tower is a truncated cone with the height of 150 meters and with the diameter at the bottom of 160 meters. The wall thickness at the bottom reaches 1.2 meters, and the top - 0.2 meters. The walls are monolithic. The basement of the structure is a field consisting of the 1,684 bored piles, the concrete pool and the impressive colonnade of 88 concrete columns with the height of 10 meters, each of them is set at an angle. Tolerance being measured in millimeters is  a strict requirement for construction of such a scale. The shell consists of 96 towers of concrete rings, constructed using a sliding movable formwork.

One of the most experienced organizations of Metrostroy,  JSC "SMU №13 Metrostroy", works on the construction of the tower. There are mixed soils at the site with soft clays and boulders. 1,684 bored piles were placed at the beginning of the construction  to strengthen the soils for the prominent basement for multi ton weight tower. Later there were made the grillage, the drainage basin and then 150-m high tower.  According to the project each electric power unit includes two cooling towers, which should be constructed in parallel with a slight slag.  At present, JSC "SMU №13 Metrostroy" completed the construction of the cooling tower №1 and started №2. 

The staff of the "Tunnel unit - 3" working on the construction of two units of Leningrad NPP-2 construct accessory buildings, storage facilities, pumping stations and reserve capacity. Specialists of "Compact" involved in the construction of several buildings of the island at the Units №1 and №2, including the building of a nuclear reactor with a height of 70 meters. The largest scope of reinforcement and concrete works is at the construction of the nuclear island buildings. For example, during the concreting of the reactor cavity, which is where molten core catcher later placed, about 3 thousand cubic meters of concrete is fitted per day.

There are specific requirements for the quality of concrete. Developed by JSC "Metrobeton" concrete mix for the construction of the reactor building of the nuclear power plant is a multicomponent structure with high technological properties (air content up to 1.5%, the volumetric weight of 2,650-2,700 kg / m³, the strength of not less than 65MPa in the early stages of hardening and not less than 79 MPa (not lower than class B60) at the age of 28 days, high frost resistance and water resistance).


 
The concrete of such high quality produced in such a quantity has never been used for construction of real estate, underground structures, any other facilities.