Start-up of the Rostov NPP will be the first after the Chernobyl disaster. All these years, nuclear power was going through hard times. Initially, it was planned to launch the first unit of the power plant in the fall of 2000. This date was announced as a result of the examination of the NPP project by the Ministry of Natural Resources and Ecology of the Russian Federation.
The need for nuclear power plants
Rostov NPP is part of the integrated power system of the North Caucasus region. It supplies electricity to 11 subjects of Russia, in the territory of which 17.7 million people live. A lot of research organized by institutes and government agencies showed that the construction of the Rostov NPP is economically and energetically beneficial.
The importance of the industry is growing amid falling blue fuel production, which is typical for 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.
Power unit
Each power unit consists of a reactor (B-320) and a turbine unit. The coolant is divided into two circuits:
- Radioactive. It includes the reactor itself, the main circulation pumps, steam generators, and a pressure compensator.
- Non-radioactive. It includes a turbine installation, water intake, the steam part of the generators and all the necessary connecting pipes.
Fuel for nuclear power plants is located in the reactor core. It contains 163 assemblies that produce heat. U-235 (slightly enriched uranium oxide) was placed inside each in tablet form. It is covered by a shell made of sealed zirconium alloy sleeves. In the primary circuit, a solution of boric acid acts as a coolant. Its base is highly purified water, under pressure of 16 MPa.
Water neutrons, which are used to transfer heat and slow down the process, made it possible to obtain the necessary temperature coefficient in the nuclear reactor 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 construction of the Rostov NPP, geology was studied at a 12-kilometer depth. 2 main layers were revealed: crystalline and sedimentary. The first consists of rocks older than the Cambrian, with the inclusion of various tectonic formations and regional gaps. The second is formed by Paleozoic, Mesozoic, and Cenozoic rocks.
The foundation of all the facilities of the nuclear power plant passes through loams and sands, and rests on the Maykop clay. The nuclear power plant construction area belongs to the whole block of crystalline foundation. Recent studies have confirmed that the structure does not exhibit tectonic activity for 300 million years.
The profile obtained by seismic acoustics corresponds to the subhorizontal arrangement of sedimentary rocks. Now the crust in this place is moving 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 foci of serious tectonic phenomena, requirements for a design earthquake were created. Its strength is 5 points, and the frequency is once every 500 years. The standards and seismic properties of existing rocks make it possible to classify this area as an earthquake zone with a magnitude of 6 points, which occur once in 5 and 10 thousand years.
Based on the data obtained, the design incorporates seismic stability 1 point higher. Design documentation calculations were made on the basis of a maximum earthquake with an intensity of 7 points.
Hydrogeological conditions
Geological exploration has identified the presence of 2 aquifers in the earth. The water layer closest to the surface is ubiquitous in the region. Surveys confirmed the depth of groundwater on the territory of the construction site of 0.2-18 m. Analysis of water showed their high destructive effect on concrete and metals.
The second aquifer is located within the boundaries of the future facility at depths from 6.8 to 39 m. After filling the Tsimlyansk reservoir, the quality of groundwater has noticeably changed for the worse: the content of minerals and the proportion of sulfates have increased. Near the facility under construction there are no underground and open sources of drinking water, from which there is a fence to supply the population. There are no stocks and opportunities for such use in the future.
Security
The safety of the Rostov NPP is ensured by a system of different barriers that hinder the possible spread of radioactive products. Protection circuit:
- Fuel structure. Its solid appearance and specific structure prevent dangerous products from spreading.
- Sealed flasks made of zirconium, which contains tableted uranium.
- Sealed walls of pipes of the first circuit with prepared aqueous solution and other equipment.
- The system of localization of the accident, which consists of a protective hermetic shell and sprinkler system. This barrier includes a powerful design with hermetic locks for people to pass, deliver goods and other equipment.
Everything that interacts with radioactive substances is inside the containment. It is designed and built in order to withstand a variety of external influences: 7-point maximum design earthquake, tornado, hurricane, shock air waves.
Protection from environmental radiation is also provided by separate sewage systems, water cooling, etc. Liquid processing and solid waste incineration is carried out at 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 individual energy blocks. The first and second of them produce 1 GW of electricity. It turns out that at the moment the power 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 commissioned.
Start-up of the 3rd unit of the Rostov NPP took place in November 2014, and its inclusion in the unified energy system took place in December. Its capacity is planned to be sent to Crimea, which is experiencing a lack of electricity.
In February-March, power unit No. 3 of the Rostov NPP was disconnected for scheduled preventive maintenance work. They were conducted in the department with turbines and a reactor, as well as in all workshops. This work is a necessary stage in the preparation of the station for output at design capacity.
The construction of the fourth unit of the Rostov nuclear plant is in full swing. At the moment, the readiness exceeds 50%. Unit 4 of the Rostov NPP is scheduled to be launched in 2017.
Accident at the Rostov NPP
On August 6, 2014, during the construction work at the 3rd power unit of the Rostov NPP, an emergency occurred: a fall on a turbine from the boom of a carriage crane.
A commission has been established to ascertain the causes of the incident and to search for responsible persons. A survey of the turbine unit showed that it was not damaged. The incident will not affect the timing of the completion of the facility.
On the morning of November 4, 2014, residents of parts of towns and cities in the southern regions of the Rostov Region experienced power outages. The problems were felt by the population of the entire North Caucasus region. The light disappeared in the homes of almost 2 million people.
The reasons for the incident were later reported. Work was underway on the southern line. At a certain point, the automation disconnected the first and second power units of the NPP from the network. In a short time, power was supplied through spare power lines.
The incident did not affect the radiation background of the region (all indicators are within normal limits), there is no reason for public concern.