Them. V. I. Lenina is a Ukrainian nuclear power plant that stopped its work due to an explosion at power unit No. 4. Its construction began in the spring of 1970, and after 7 years it was put into operation. By 1986, the station consisted of four blocks, to which two more were being completed. When the Chernobyl nuclear power plant, or rather, one of the reactors, exploded, its work was not stopped. The sarcophagus is currently under construction and will be completed by 2015.
Station Description
1970-1981 - during this period of time, six power units were built, two of which did not have time to start up until 1986. To cool the turbines and heat exchangers, a bulk pond was built between the Pripyat River and the Chernobyl Nuclear Power Plant.
Before the accident, the plant's generating capacity was 6,000 MW. Currently, work is underway to transform the Chernobyl nuclear power plant into an environmentally friendly design.
Start of construction
To select a suitable site for the construction of the first nuclear power plant, the design institute of the capital of Ukraine examined the Kyiv, Zhytomyr and Vinnitsa regions. The most convenient place was the territory on the right side of the Pripyat River. The land, on which construction soon began, was unproductive, but fully met the requirements for maintenance. This site was approved by the State Technical Commission of the USSR and the Ministry
February 1970 was marked by the beginning of the construction of Pripyat. The city was created specifically for power engineers. The fact is that during the first years, the personnel serving the station had to live in dormitories and rented houses in the villages adjacent to the Chernobyl nuclear power plant. Various enterprises were built in Pripyat to provide jobs for their family members. Thus, over the 16 years of the city's existence, it has been equipped with everything necessary for a comfortable living for people.
1986 accident
At 01:23 am, a design test of the turbine generator of the 4th power unit was started, which caused the Chernobyl nuclear power plant to explode. As a result, the building collapsed, causing more than 30 fires. The first victims were V. Khodemchuk, an operator of circulation pumps, and V. Shashenok, an employee of a commissioning plant.
A minute after the incident, the Chernobyl security guard was informed about the explosion. Firefighters arrived at the station as soon as possible. V. Pravik was appointed head of the liquidation. Thanks to his skillful actions, the spread of fire was stopped.
When the Chernobyl nuclear power plant exploded, the environment was contaminated with radioactive substances such as:
plutonium, uranium, iodine-131 lasts about 8 days);
Cesium-134 (half-life - 2 years);
Cesium-137 (from 17 to 30 years);
Strontium-90 (28 years old).
The whole horror of the tragedy lies in the fact that from the inhabitants of Pripyat, Chernobyl, as well as the entire former Soviet Union for a long time they concealed why the Chernobyl nuclear power plant exploded and who was responsible for this.
Source of accident
On April 25, the 4th reactor was supposed to be stopped for the next repair, but instead they decided to conduct a test. It consisted in creating an emergency situation in which the station itself would cope with the problem. By that time there were already four such cases, but this time something went wrong...
The first and main reason for the explosion of the Chernobyl nuclear power plant is the negligent and unprofessional attitude of the personnel to the risky experiment. The workers maintained the unit's power at 200 MW, which led to self-poisoning.
As if nothing had happened, the staff watched what was happening, instead of taking the control rods out of work and pressing the A3-5 button - for emergency shutdown of the reactor. As a result of inaction, an uncontrolled chain reaction began in the power unit, which caused the Chernobyl nuclear power plant to explode.
In the evening (at about 20.00) a more intense fire took place in the central hall. People were not attracted this time. It was liquidated with the help of helicopters.
For all the time, in addition to firefighters and station personnel, about 600 thousand people were involved in rescue operations.
What caused the Chernobyl nuclear power plant to explode? There are a number of reasons that contributed to this:
The experiment had to be carried out at any cost, regardless of the abrupt change in the behavior of the reactor;
Decommissioning of working technological protections that would shut down the power unit and prevent an accident;
The suppression by the management of the station of the magnitude of the catastrophe that happened, as well as the reasons why the Chernobyl nuclear power plant exploded.
Consequences
As a result of eliminating the consequences of the spread of radioactive substances, 134 firefighters and employees of the station developed radiation sickness, 28 of them died within a month after the accident.
Signs of exposure were vomiting and weakness. First, first aid was provided by the medical staff of the station, and after that the victims were transported to hospitals in Moscow.
At the cost of their own lives, the rescuers prevented the fire from moving to the third unit. Thanks to this, it was possible to avoid the spread of fire in neighboring blocks. If the extinguishing had not been successful, the second explosion could have exceeded the power of the first one by 10 times!
Accident on September 9, 1982
Until the day the Chernobyl nuclear power plant exploded, there was a case of destruction at power unit No. 1. During a test run of one of the reactors at a power of 700 MW, a kind of explosion of the fuel assembly and channel No. 62-44 occurred. The result of this was the deformation of the graphite masonry and the release of a significant amount of radioactive substances.
The explanation for why the Chernobyl nuclear power plant exploded in 1982 can be the following:
Gross violations of the workshop personnel in the regulation of water flow in the channels;
The rest of the internal stress in the walls of the channel zirconium pipe, which arose as a result of a change in technology by the plant that produced it.
The government of the USSR, as usual, decided not to inform the population of the country why the Chernobyl nuclear power plant exploded. The photo of the first accident has not survived. It is even possible that it never existed.
Station representatives
The following article presents the names of employees and their positions before, during and after the tragedy. Bryukhanov Viktor Petrovich was the director of the station in 1986. Two months later, Pozdyshev E.N. became the manager.
Sorokin N. M. was the deputy engineer for operation in the period 1987-1994. Gramotkin I. I. from 1988 to 1995 served as the head of the reactor shop. Currently, he is the General Director of the SSE "Chernobyl NPP".
Dyatlov Anatoly Stepanovich - Deputy Chief Engineer for Operations and one of those responsible for the accident. The reason for the explosion of the Chernobyl nuclear power plant was to conduct a risky experiment, which was headed by this particular engineer.
Exclusion zone at present
The long-suffering young Pripyat is now contaminated with radioactive substances. They gather most often in the ground, houses, ditches and other depressions. Only a water fluoridation station, a special laundry, a checkpoint and a garage for special equipment remained in the city from the existing facilities. After the accident, Pripyat, oddly enough, did not lose the status of a city.
With Chernobyl, the situation is quite different. It is safe for life, people serving the station and the so-called self-settlers live in it. The city today is administrative center management of the exclusion zone. Chernobyl concentrates enterprises that maintain the nearby territory in an environmentally safe state. Stabilization of the situation is to control the radionuclides in the Pripyat River and the airspace. The city has personnel of the Ministry of Internal Affairs of Ukraine, which protects the exclusion zone from illegal entry of unauthorized persons.
Women and children were the first to be evacuated. In this corner of the former Soviet Union, there was a shortage of buses. Buses from other regions of the country came here to take 50 thousand people out of the city. The length of the bus column was 20 kilometers, which meant that when the first bus left Pripyat, the pipes of the power plant were no longer visible to the last one. In less than three hours, the city was completely empty. And so it will remain forever. In early May, the evacuation of people living in the 30-kilometer Exclusion Zone around Chernobyl was organized. Disinfection works were carried out in 1840 settlements. However Chernobyl zone the alienation was not completed until 1994, when the last inhabitants of the villages in its western part were moved to new apartments in the Kyiv and Zhytomyr regions.
Today Pripyat is a city of ghosts. Despite the fact that no one lives there, the city has its own elegance and atmosphere. It did not cease to exist, unlike the neighboring villages, which were buried in the ground by excavators. They are marked only on road signs and maps of the countryside. Pripyat, as well as the entire 30-kilometer Exclusion Zone, is guarded by the police and patrol service. Despite their constant watch, the city was repeatedly subjected to robbery and looting. The whole city has been looted. There was not a single apartment left, no matter where the thieves who took away all the jewelry would visit. In 1987, residents had the opportunity to return to collect a small portion of their belongings. The military plant "Jupiter" worked until 1997; the famous swimming pool "Azure" operated until 1998. At the moment, they are looted and destroyed even more than the apartments and schools in the city combined. There are three other parts of the city that are still in operation: a laundry (for the Chernobyl nuclear power plant), garages for trucks, and a deep well with a pumping station that supplies water to the power plant.
The city is full of 1980s graffiti, signs, books, and images mostly associated with Lenin. His slogans and portraits are everywhere - in the Palace of Culture, a hotel, a hospital, a police station, as well as in schools and kindergartens. Walking through the city is like going back in time, the only difference is that there is no one here, not even birds in the sky. One can only imagine a picture of the era when the city flourished, during the tour we will show you historical photos. To give you a vivid idea of the times of the Soviet Union, we offer a Soviet form, a retro walk in our RETRO TOUR. Everything was built from concrete. All buildings are of the same type, as in other cities built under the Soviet Union. Some houses are overgrown with trees so that they are barely visible from the road, and some buildings are so worn out that they collapse from a large number drunk snow. Chernobyl is a life example of how Mother Nature takes her toll over the efforts of many people. In a few decades, only ruins will remain from the city. There is not a single place like this in the world.
Chernobyl nuclear power plant during construction
The territory of the Polesie region has been inhabited and developed by people for several millennia. By creating new infrastructure, building cities, drying up swamps and irrigating land, people recorded their history.
The Pripyat River at the Chernobyl Nuclear Power Plant
Chernobyl and Pripyat
Compared to the young Pripyat, the city of Chernobyl is already several centuries old. The time of Pripyat stopped when she reached her 16th birthday. In turn, Chernobyl is considered one of the oldest settlements Ukrainian Polissya.
A few centuries ago, this city combined not only monuments of culture and history. At the same time, Chernobyl also united different nationalities. Representatives of different nations lived in commonwealth with each other.
Moreover, the modern exclusion zone was previously a real historical place, because there were both Tatar barrows and the ruins of old monasteries. Of course, there are also memorable places from the time of the Great Patriotic War. However, the Chernobyl tragedy on April 26, 1986 made many of the above disappear, while the once historical lands remained mothballed for many centuries.
Graveyard of radioactive equipment in Chernobyl
What year did the Chernobyl tragedy occur?
The Chernobyl tragedy occurred in the year when the Soviet energy was supposed to reach new stage formation, because in addition to planned experiments, the Chernobyl NPP was preparing to launch new power units with the RBMK-1000 reactor. The successful use of nuclear resources has stifled the most important thing that a specialist should have - responsibility. And it is not only the responsibility for the safety of others. This is mindfulness while using the gigantic power of nuclear fuel.
The RBMK-1000 reactor and the nuclear fuel it contains turned out to be common man invincible opponents. Alluring with its potential, he succumbed and ended up in the hands of a man, but at an unexpected moment, when everyone allowed himself to relax, he brought a great tragedy to Chernobyl and its environs.
Consequences of the Chernobyl accident
The tragedy in Chernobyl in 1986 is considered the largest in the history of mankind. The moment of the explosion of the reactor of the fourth power unit was accompanied by the formation of a fiery column, which stretched several kilometers upwards. This column contained radioactive particles and penetrated even into those layers of the atmosphere, which, it seemed, simply could not reach.
The Chernobyl disaster occurred at 01:23 on April 26: a reactor explosion occurred at the 4th power unit with a partial collapse of the power unit building. In the premises and on the roof started a strong fire. A mixture of the remnants of the reactor core, molten metal, sand, concrete and nuclear fuel spread over the premises of the power unit. The explosion released a huge amount of radioactive elements into the atmosphere.
Causes of the accident
A day earlier, on April 25, Unit 4 was shut down for preventive maintenance. During this repair, a run-down test of the turbogenerator was carried out. The fact is that if superheated steam is no longer supplied to this generator, it will be able to generate energy for a long time before it stops. This energy could be used in case of emergencies at nuclear power plants.These were not the first tests. The previous 3 test programs were unsuccessful: the turbogenerator gave less energy than expected. There were high hopes for the results of the fourth test. Leaving out details, the activity of the reactor is controlled by the insertion and withdrawal of the absorber rods. At the Chernobyl nuclear power plant, these rods had an unsuccessful design, due to which, when they were abruptly withdrawn, an “end effect” arose - the reactor power, instead of falling, increased sharply.
Unfortunately, such features of the rods were studied in detail only after the Chernobyl disaster, but the operating personnel should know about the “end effect”. The personnel did not know about this, and when simulating an emergency shutdown, that very sharp increase in reactor activity occurred, which led to an explosion.
The power of the explosion is evidenced by the fact that the 3,000-ton concrete cover of the reactor came off, pierced the roof of the power unit, carrying out the loading and unloading machine along the way.
Consequences of the accident
As a result of the Chernobyl disaster, 2 employees of the nuclear power plant died. 28 people died later from radiation sickness. Of the 600 thousand liquidators who took part in the work at the destroyed station, 10% died from radiation sickness and its consequences, 165 thousand became disabled.A huge amount of equipment used during the liquidation had to be written off and left in cemeteries, right on the contaminated territory. Subsequently, the equipment slowly began to go into scrap metal and.
Huge territories were contaminated with radioactive substances. An exclusion zone was created within a radius of 30 km from the nuclear power plant: 270 thousand were resettled in other areas.
The territory of the station was deactivated. A protective sarcophagus was built over the destroyed power unit. The station was closed, but due to a lack of electricity in 1987, it was reopened. In 2000, under pressure from Europe, the station was closed completely, although it still performs distribution functions. The protective sarcophagus fell into disrepair, but there are no funds for the construction of a new one.
On April 25, 1986, the shutdown of the fourth reactor was scheduled for the next scheduled preventive maintenance to test the so-called “turbine generator rotor run-down” mode. However, this mode has not yet been worked out at the plant and has not even been introduced in principle at nuclear power plants with RBMK-type reactors. However, tests on April 25, 1986 were already the fourth to be carried out at the Chernobyl nuclear power plant. The first attempt, back in 1982, showed that the coastdown voltage dropped faster than originally planned. Subsequent experiments carried out at the station after the refinement of the turbogenerator equipment in 1983, 1984 and 1985 also, for various reasons, ended unsuccessfully.
The Chernobyl accident. How it happened
On April 26, 1986, at the fourth power unit of the Chernobyl nuclear power plant, during the operation of the RBMK-1000 reactor at a power of 200 MW, a powerful explosion occurred, which resulted in the complete destruction of the nuclear reactor of the station. Hot pieces of fuel assemblies and graphite were ejected from the reactor. Fragments of deadly irradiated fuel rods (fuel elements), graphite and even entire parts of metal structures were scattered over the roofs of the station's workshops and neighboring buildings located in the surrounding area. A fire broke out in various rooms of the station and on the roof. In addition to nuclear fuel, the reactor core at the time of the accident contained fission products and transuranium elements - various kinds of radioactive isotopes formed during the operation of the reactor. It was they who posed the greatest threat to the biosphere. In the environment, due to the maximum temperatures and the process of nuclear fuel melting, along with hot air, a huge amount of radioactive substances was released, including isotopes of such chemical elements like uranium, plutonium (half-life 8 days), cesium-134 (half-life 2 years), (half-life 33 years), (half-life 28 years), and radioactive dust.
The data of isotopic analysis of the first samples of air, water and soil taken on the territory of the station in Chernobyl in the first days after the accident - from April 26 to May 1 - indicated that about a third of the total activity was accounted for by the iodine-131 isotope. In addition to it, isotopes of barium-140 and lanthanum-140, cesium-137 and cesium-134, ruthenium-103, zirconium-95, tellurium-132, cesium-141 and neptunium-239 were found in the collected samples, as well as in the nearest zone , the resettlement zone isotopes of strontium-90 and plutonium-239 and plutonium-240.
In urban areas, hazardous substances mainly settled on flat surfaces: on lawns, roads, roofs. And since the direction of the wind was not constant, the radioactivity dissipated, and, above all, in the area around the Chernobyl nuclear power plant. In the area of Chernobyl nuclear power plant radioactivity reached 15,000 roentgens/hour. In the near zone of the accident (10-30 km from the Chernobyl nuclear power plant), the radionuclide composition of the fallout was close to its composition in the fuel, and outside this zone, the fractionation of radionuclides iodine-131 and cesium-137 was more significant. In the near zone, a large amount of "hot particles" was noted to fall out.
A significant part of the isotopes of strontium and plutonium was within a hundred kilometers from the station, as they were contained in heavy particles. Iodine and cesium spread over a wider area. Sufficiently intense fallout of strontium-90 (up to 100 kBq*m2) took place in the near zone of the Chernobyl nuclear power plant, only a relatively small number of sites with a density of contamination of strontium-90 (37-100 kBq*m2) were located in the Gomel and Mogilev regions of Belarus and the Bryansk region of Russia . Areas with a high content of plutonium were within the near zone of the Chernobyl nuclear power plant (30 km zone), where the density of plutonium contamination was noted to be more than 3700 Bq/m2. The excess of the global level for plutonium-239 and plutonium-240 in the upper soil layer (0-5 cm) averaged 175 times, and in more remote areas the content did not exceed 0.07-0.7 kBq*m2.
Part of the fuel, including deadly radioactive fission residues, including plutonium, in finely dispersed, droplet and gaseous form, together with superheated steam, rose to the clouds and moved with the wind mainly in a westerly direction, gradually settling and infecting the entire surrounding area along the way. The radioactive plume stretched to the west - over the European part of the USSR, to the east - to the territory of Eastern Europe and north to the Scandinavian countries. At the same time, the bulk of the contaminated sediments settled on the territory of present-day Belarus - then the Byelorussian SSR. The radiation situation in the early period was determined by short-lived fission products and neutron activation, including iodine-131. In later periods, the determining radionuclides were cesium-134 and cesium-137, and in some local areas also strontium-90. The main dose-forming radionuclide in the long term was cesium-137, the content of which in environment the radiological situation was assessed. The total activity of cesium-137 deposited on the territory former USSR, was equal to 4 * 1016 Bq (including in Belarus - about 41%, Russia - 35%, Ukraine - 24% and other republics - less than 1%). The vast territory subjected to radioactive contamination has a complex configuration. The area with the level of cesium-137 contamination over 1 Ku*km2 (37 kBq*m2) occupied about 150 thousand km2. On the territory of Russia, the area with a density of caesium-137 contamination from 555-1480 kBq*m2 is 2100 km2, and over 1480 kBq*m2 is 310 km2. Many of the victims are still being treated in clinics Ukraine, Belarus and Russia.
Another part of the radioactive contents of the reactor melted, a mixture of molten metal, sand, concrete and fragments of fuel assemblies leaked through cracks in the lower part of the reactor vessel beyond its limits, including penetrating into the under-reactor rooms. The surviving part of the metal structures, fuel cells and graphite continued to melt for several days after the explosion and turned into a kind of mass that “burned through” the lower biological protection from steel sheets and (in the main part) concrete, mixed with the latter, and poured out of the power unit building avalanche-like mass to the lower marks, and frozen in the form of the famous "elephant's foot". dragged on for decades and is still unfinished.