Construction of Rostov NPP. Accident at Rostov NPP

The launch of the Rostov NPP will be the first after the Chernobyl disaster. All these years the nuclear power industry was going through hard times. Initially, the first power plant unit was planned to be launched in the fall of 2000. This date was announced following the results of the NPP project examination by the Ministry of Natural Resources and Ecology of the Russian Federation.

The need for nuclear power plants

Rostov NPP is part of the unified energy system of the North Caucasus region. It supplies electricity to 11 constituent entities of Russia, in which 17.7 million people live. A lot of studies organized in institutes and state structures have shown that the construction of the Rostov NPP is economically and energetically beneficial.

The importance of the industry increases against the background of a decline in the production of blue fuel, which is typical for the central and southern regions. The universal project for the construction of the Rostov NPP provides for the construction of a separate independent building for each power unit, in which the VVER-1000 nuclear reactor will be installed.

Unit construction

Each power unit consists of a reactor (V-320) and a turbine unit. The heat carrier is divided into two circuits:

• Radioactive. It includes the reactor itself, main pumps that provide circulation, steam generators, pressure compensator.
• Non-radioactive. It includes a turbine unit, water intake, steam generator part and all necessary connecting pipes.

Fuel for nuclear power plants is located in the core of the reactor. There are 163 assemblies that produce heat. Inside, U-235 (slightly enriched uranium oxide) is placed in a tablet form. It is covered by a shell of sealed sleeves made of zirconium alloy. In the first circuit, a solution of boric acid acts as a coolant. Its basis is highly purified water, which is under pressure of 16 MPa.

The water neutrons, which are used for heat transfer and slowing down the process, made it possible to obtain in the nuclear reactor the necessary temperature coefficient with the sign "-". He determined the stability of VVER-1000 and its ability to automatically regulate.

And what's under the station?

In the area of the structure of the Rostov NPP, geology was studied at a 12-kilometer depth. Two main layers were identified: crystalline and sedimentary. The first consists of rocks older than the Cambrian, with the inclusion of different tectonic formations and regional discontinuities. The second is formed by rocks of the Paleozoic, Mesozoic and Cenozoic.

The foundation of all the facilities of the nuclear power plant passes through loams and sands, and rests on the clay of Maikop. The area of NPP construction belongs to the whole block of the crystalline basement. Recent studies have confirmed that the structure does not show tectonic activity for 300 million years.

The profile obtained by the method of seismic acoustics corresponds to the subhorizontal disposition of sedimentary rocks. Now the earth's crust moves at a speed of 0 ... 4.5 mm per year. Studies of the concentration of some substances in groundwater and air have not revealed tectonic faults.

Seismicity of the area

When studying the nearest and remote centers of serious tectonic phenomena, requirements were created for a projected earthquake. Its strength is 5 points, and the frequency is one time in 500 years. The standards and seismic properties of the available rocks make it possible to attribute this region to the earthquake zone by the force of 6 points, which occur once every 5 and 10 thousand years.

On the basis of the obtained data, the construction is seismic-resistant to 1 point higher. Calculations of project documentation were made on the basis of a maximum earthquake of intensity 7 points.

Hydrogeological conditions

Exploration determined the presence of 2 aquifers in the ground. Near the surface of the layer of water is widespread in the area everywhere. The investigations confirmed the depth of groundwater occurrence in the construction site area of 0.2-18 m. Analysis of water showed a high destructive effect on concretes and metals.

The second aquifer is within the boundaries of the future facility at depths from 6.8 to 39 m. After filling Tsimlyansk reservoir, the quality of groundwater has changed significantly for the worse: the mineral content and the proportion of sulphates have increased. Near the facility under construction, there are no underground and open sources of drinking water, from which the fence is used to supply the population. There are no reserves and opportunities for such use in the future.

Security

Safety of Rostov NPP is ensured by a system of various barriers that prevent the possible spread of radioactive products. Protection scheme:

• Fuel structure. Its solid appearance and specific structure does not allow spreading to dangerous products.
• Sealed zirconium flasks containing pelletized uranium.
• Hermetic walls of pipes of the first circuit with the prepared aqueous solution and other equipment.
• The accident localization system, which consists of a protective hermetic shell and a sprinkler system. This barrier includes a powerful structure with airtight locks for people to pass through, deliver goods and other equipment.

Everything that interacts with radioactive substances is inside the containment. It is designed and built taking into account that to withstand a variety of external influences: a 7-point maximum estimated earthquake, a tornado, a hurricane, shock air waves.

Protection from environmental radiation is also provided by separate sewage systems, water cooling, etc. Liquid processing and solid waste incineration are carried out on the territory of the station. Spent fuel is aged in special pools for a three-year period and is transported in special containers by rail.

Number of power units

The power of the Rostov NPP is determined by the sum of the indices of the individual power units. The first and the second of them produce 1 GW of electricity. It turns out that at the moment the capacity of the nuclear power plant is 2 GW. In 2001 and 2010 The first and second power units of the Rostov nuclear power plant were put into operation.

The launch of Unit 3 of Rostov NPP took place in November 2014, and its inclusion in a unified energy system took place in December. Its capacity is planned to be sent to the Crimea, which lacks electricity.

In February-March the power unit No. 3 of Rostov NPP was shut down for scheduled preventive maintenance work. They were conducted in a department with turbines and a reactor, as well as in all workshops. These works are a necessary stage of the station's preparation for reaching its designed capacity.

The work on the construction of the fourth block of the Rostov nuclear power plant is under way. At the moment, the readiness exceeds 50%. The power unit No. 4 of Rostov NPP is planned to be launched in 2017.

Accident at Rostov NPP

On August 6, 2014, during the construction work at the 3rd power unit of Rostov NPP, an emergency occurred: a fall onto the turbine from the boom of the crane .

A commission was established to find out the causes of the incident and search for responsible persons. The inspection of the turbine unit showed that it was not damaged. What has happened will not affect the delivery date of the facility.

On the morning of 4/11/2014, residents of some of the towns and cities in the southern regions of the Rostov region experienced interruptions in the supply of electricity. The population of the entire North Caucasus region felt the problems. Light disappeared in the homes of almost 2 million people.

Later reported the reasons for what happened. Work was done on the southern line. At some point, the automation shut off the first and second power units of the nuclear power plant. In the shortest possible time, power was supplied through spare power lines.

The incident did not affect the radiation background of the region (all indicators are within the norm), there are no reasons for concern of the population.