Nuclear power plant Chernobyl accident. Chaes them

It was planned that the Chernobyl nuclear power plant would be built by the best engineers and architects from around Soviet Union. This Nuclear Power Plant was supposed to provide electric power resources not only to the entire territory of Ukraine, but also to some part of the Russian SFSR. Power units at the nuclear power plant were built at an accelerated pace. The then plans and deadlines were exceeded by several times.

The Chernobyl nuclear power plant was built and gradually opened for the holidays and parades in the city. However, the youth of the city of Chernobyl, a well-built nuclear power plant, which at that time was considered the best in the entire Soviet Union - all this turned into tragic memories in one day, when the circumstances played a cruel joke on the city and its inhabitants. On April 26, 1986, the Chernobyl nuclear power plant exploded, it caught fire and after the explosion released thousands of tons of radioactive substances and elements into the sky, which made the previously ordinary city on the map life-threatening.

Briefly about the construction of the Chernobyl nuclear power plant

The area on which they were going to build a nuclear power plant, got out for a long time and as carefully as possible. In order to find the most suitable area for the construction of the Chernobyl nuclear power plant, the special brigade. People from this brigade studied the map and traveled to many cities in Ukraine, looking for suitable territories. Soon the Chernobyl nuclear power plant appeared on the map of Ukraine.

At that time, a modern-type nuclear power plant was supposed to fully provide electricity to 27 regions of Ukraine, as well as the Rostov region. It was necessary that the area where the then-Chernobyl nuclear power plant was supposed to be located was located no more than 340-350 kilometers from the places where its resources come.

As a result of the work done by the commission and many studies, a point on the map near the village of Kopachi in the Kiev region was chosen for the construction of the Chernobyl nuclear power plant. This area was approved for the reason that this area had good water supply conditions, as well as a high-quality highway network and a convenient location relative to the capital of the country.

For the construction of the Chernobyl station, the state allocated 1,400 hectares of land, as well as 130 hectares of forest. Some time after the approval, a cleared construction site and a fenced area appeared 15 kilometers from Chernobyl.

The place where the Chernobyl nuclear power plant is located can now be viewed on the Yandex map. Chernobyl on the Yandex map is drawn in sufficient detail. Google maps also allow you to look at the territory of the Chernobyl nuclear power plant after so many years. If you wish, on the Internet you can find a map of radioactive fallout as a result of the accident at the Chernobyl nuclear power plant.

Read about how to get to Chernobyl:

Who built the Chernobyl nuclear power plant?

construction nuclear power plant was engaged in a separate institute of the USSR "Hydroproject". The departments that contained reactors and structures dangerous to human life were designed and built thanks to a special All-Union Research Institute energy technologies. With the advent of 1970, construction teams at the Chernobyl nuclear power plant began to prepare a large pit, which was supposed to serve as a place for the first reactor. In 1975, the work of the first power unit started. Three years later, two power units of the Chernobyl power plant were fully operational. In the autumn of 1978, the Chernobyl nuclear power plant celebrated its first 10 billion kW of electricity generated. Plans for further construction were approved.

During the construction and construction of the nuclear power plant, electricity generation increased, and the new nuclear power plant gained power and speed. In 1981, the third power unit was put into operation. He was ahead of plans for his appearance by 3 years. Official estimates and plans were set for 1984. In 1984, the fourth power unit of the Chernobyl nuclear power plant was put into operation and fully launched. It was set up to generate a design capacity of 1,000 MW.

The USSR Ministry of Energy decided at that time to use a high-power reactor of 1000 MW at the Chernobyl plant. For the entire Union, such reactors were only in the Leningrad and Kursk regions. At that time, they were design structures that were built without mandatory protective structures and shields, such as a water savings barrier in case of unforeseen fires and other incidents. If the fourth reactor had been built according to all the necessary technologies and rules, then the water from the reservoir under its base would have extinguished the fire and prevented a catastrophe in 1986.

In April, on the eve of the disaster, the Chernobyl nuclear power plant generated its 4,000 MW of electricity. If the explosion and catastrophe had not happened, then the construction of the station at the point chosen on the map would not have stopped. It was planned to build two more power units, which would increase the volume of electricity generation in Chernobyl to 6000 MW.

How did the disaster happen?

The nuclear power plant in Chernobyl is known to every person in the post-Soviet space due to very unpleasant events. April 26, 1986 was marked by the worst man-made accident in the history of mankind. It was on this day that a terrible explosion occurred at a particularly dangerous industrial facility, which includes a nuclear power plant. The result was an infection of a large territory, which led to a thousand deaths, a large number of practically incurable diseases, mutations and the appearance on the map of Ukraine of the so-called exclusion zone, which is 30 km long, access to which is allowed only to representatives of special services and units.

Chernobyl nuclear power plant - a monument to human negligence or the imperfection of technology?

Chernobyl nuclear power plant or Chernobyl nuclear power plant named after V.I. Lenin is the first nuclear power plant that appeared on the territory of Ukraine. The station was located in the eastern part of the country, not far from the borders with neighboring Belarus. The station was built on the banks of the small river Pripyat, which gave its name to the city that when there was an explosion in Chernobyl (Chernobyl) into the "dead zone".

By that time, 4 power units were operating, built on the basis of RBMK-1000 reactors, which have a high power. At the same time, this type of reactor at the time of 1986 had multiple design flaws hidden at the time of their operation, which, according to most experts, could become the reasons that caused nuclear explosion nuclear power station. In particular, one of the reasons for the explosion that occurred during the experiment on the “run-out” of the generator was not only the mistakes of the direct executors (installation operators), but also flaws in the program, which consisted in an insufficient degree of preparedness of safety issues.

If we talk about the reasons that led to such a strong explosion that caused the destruction of an entire power unit, then we can mention the imperfection of the reactor "acceleration" system, which led to an initial decrease in the power of the power unit, and then a sharp increase in it, which led to a reaction, which was caused by a whole series of powerful explosions that destroyed a thick concrete fence.

Accident: chronicle of events

On April 25, the day before the tragedy, the 4 power unit that exploded was stopped for a scheduled repair procedure, during which the obsolete equipment is usually replaced and new units are installed. This procedure involves further testing of newly installed parts in order to avoid abnormal situations. It was on the 25th that it was planned to test the turbine generator rotors, the use of which improved the power supply to the circulation pumps, which ensured uninterrupted operation of the station in the event of unscheduled power outages.

At the same time, attempts to introduce such a system were carried out for a long time and the first tests took place as early as 1982. But during the test launches, it was found that the power drops faster than planned, which could be critical for the normal functioning of the reactor.

During the experiment in April 1986, initially the power at which the Chernobyl power plant, namely its 4th power unit, was lowered to the forecast figure of 700 MW. Then there was an unauthorized decrease in power, first to 500 MW. Subsequently, when the power control system switched to automatic mode, due to incorrect actions of the plant operator, the nuclear power dropped to zero, while the thermal power stopped at 330 MW, which was only 0.1% of the nominal thermal power of the plant. All station personnel who were in charge of the experiment and located in the control room used the method of extracting the rods to increase the power of the reactor. The measures taken made it possible to increase the values ​​up to 200 MW. This made it possible to start four more circulation pumps.

A decrease in the number of revolutions of the pumping units connected to the "run-out" generator, and the dynamics of the movement of the steam coefficient of reactivity towards positive values, the reactor of the station showed a tendency to a sharp increase in power, which became simply uncontrollable in the next period of time, which was also caused by a flaw in the design of the reactor rods . The failure of the automatic reactor shutdown system in time caused the at half past two in the morning there was an explosion at the Chernobyl power plant. The strength of the blast wave was such that not only the reactor was completely destroyed, but also the entire building in which the power unit was located was damaged. Directly during the accident, two operators who were near the console died. The accident resulted in a massive release into the atmosphere a large number radioactive elements, including isotopes of uranium, plutonium, radioactive iodine, cesium, strontium. It is the emissions from sources available in the reactor ionizing radiation represent the greatest danger in explosions at nuclear power plants.

Nuclear power plant Chernobyl: life after

Even though what happened terrible catastrophe The nuclear power plant operated for several more years. The first year after the explosion, due to the danger of radiation contamination, the work of all other power units was suspended, but already at the end of 1986, after the construction of a sarcophagus over the destroyed reactor, the work of Units 1 and 2 was resumed. In 1987, the 3rd power unit was put into operation.

What happened caused a very strong resonance in society and became a real blow to the world nuclear energy. Under such conditions, the normal operation of the station could not be carried out for a long time. It was the pressure of the European community, in particular the European Union, that led to the fact that already at the end of 1995 a corresponding document was signed to suspend the operation of the station. In 2000, in December, the last 3rd power unit was shut down, after which the station was officially declared inoperative.

Chernobyl map

After the construction of the sarcophagus over the destroyed reactor, which was built in a hurry, a lot of time has passed and its gradual destruction is observed, which leads to the spread of radiation outside. It was decided to hold a tender for the construction of a new shelter that could provide an adequate level of security. The French company that won the tender began construction of a new sarcophagus in the form of a monumental arch that would completely cover not only the reactor itself, but also the surrounding area. At the moment, the construction of the protective dome has not been completed.

On April 26, 1986, during a completely planned procedure at the Chernobyl nuclear power plant, everything began to develop in a completely different way, as described by the regulations and as suggested by common sense...

Matvey Vologzhanin

Any event in the world consists of so many factors that we can safely say that the whole universe takes part in it in one way or another. The human ability to perceive and comprehend reality ... well, what can we say about it? It is possible that we have already almost overtaken some plants in terms of success in this area. While we are just living, you can not pay much attention to what is actually happening around you. Sounds of varying volumes are heard on the street, more or less cars seem to be moving in different directions, either a mosquito flew past the nose, or the remnants of yesterday's hallucination, and around the corner they hurriedly bring an elephant, which you did not even notice.

Workers of the Chernobyl nuclear power plant. 1984

But we are calm. We know that there are Rules. The multiplication table, hygienic norms, the Military Regulations, the Criminal Code and Euclidean geometry - all that helps us to believe in the regularity, orderliness and, most importantly, the predictability of what is happening. How was it with Lewis Carroll - "If you hold a red-hot poker in your hands for a very long time, then in the end you can get slightly burned"?

Troubles begin when disasters occur. Whatever order they may be, they almost always remain inexplicable and incomprehensible. Why did the sole of this still completely new left sandal fall off, while the right one is full of strength and health? Why, out of a thousand cars that drove through a frozen puddle that day, only one flew into a ditch? Why on April 26, 1986, during a completely planned procedure at the Chernobyl nuclear power plant, everything began to develop in a completely different way than usual, not in the way described by the regulations and as common sense suggests? However, let's give the floor to a direct participant in the events.

What happened?

Anatoly Dyatlov

“On April 26, 1986, at one hour twenty-three minutes forty seconds, Alexander Akimov, the shift supervisor of Chernobyl Unit 4, ordered the reactor to be shut down at the end of the work carried out before the shutdown of the power unit for the planned repairs. The reactor operator Leonid Toptunov removed the cap from the AZ button, which prevents accidental erroneous pressing, and pressed the button. At this signal, 187 control rods of the reactor began to move down into the core. The backlight lamps on the mnemonic panel lit up, and the arrows of the rod position indicators began to move. Alexander Akimov, standing half-turned to the reactor control panel, watched this, he also saw that the “bunnies” of the AR imbalance indicators darted to the left, as it should be, which meant a decrease in the reactor power, turned to the safety panel, which he was observing from the ongoing experiment.

But then something happened that even the most unbridled fantasy could not predict. After a slight decrease, the reactor power suddenly began to increase at an ever-increasing rate, alarms appeared. L. Toptunov shouted about an emergency increase in power. But there was nothing he could do. He did everything he could - he held the AZ button, the CPS rods went into the active zone. There are no other resources at his disposal. Yes, and everyone else too. A. Akimov sharply shouted: "Turn off the reactor!" He jumped to the console and de-energized the electromagnetic clutches of the CPS rod drives. The action is correct, but useless. After all, the CPS logic, that is, all its elements of logical circuits, worked correctly, the rods went into the zone. Now it is clear: after pressing the AZ button, there were no correct actions, there were no means of salvation ... Two powerful explosions followed with a short interval. The AZ rods stopped moving before going half way. They had nowhere else to go. In one hour, twenty-three minutes, forty-seven seconds, the reactor was destroyed by a power boost on prompt neutrons. This is a collapse, the ultimate catastrophe that can happen in a power reactor. They didn’t comprehend it, they didn’t prepare for it.”

This is an excerpt from Anatoly Dyatlov's book Chernobyl. How it was". The author is the deputy chief engineer of the Chernobyl nuclear power plant for operation, who was present that day at the fourth unit, who became one of the liquidators, recognized as one of the perpetrators of the tragedy and sentenced to ten years in prison, from where he was released two years later to die from radiation, where he and managed to write his memoirs before he died in 1995.

If someone taught physics very badly at school and vaguely imagines what is happening inside the reactor, he probably did not understand what was described above. In principle, this can be conditionally explained in this way.

Imagine that we have tea in a glass, which is trying to boil non-stop on its own. Well, here's the tea. So that he does not smash the glass to smithereens and fill the kitchen with hot steam, we regularly lower metal spoons into the glass - in order to cool it down. The colder we need tea, the more spoons we shove. And vice versa: to make the tea hotter, we pull out the spoons. Of course, the carbide-boron and graphite rods that are placed in the reactor work according to a slightly different principle, but the essence of this does not change much.

Now let's remember what the main problem stands in front of all the power plants in the world. The most trouble for power engineers is not with fuel prices, not with drinking electricians and not with crowds of “greens” picketing their checkpoints. The biggest trouble in the life of any power engineer is the uneven power consumption by the station's customers. The unpleasant habit of mankind to work during the day, sleep at night, and even wash in chorus, shave and watch TV shows leads to the fact that the energy produced and consumed, instead of flowing in a smooth uniform stream, is forced to jump like a mad goat, which causes blackouts and other troubles. After all, instability in the operation of any system leads to failures, and getting rid of excess energy is harder than producing it. Especially great difficulties with this are precisely at nuclear power plants, since chain reaction it is rather difficult to explain when it should go more actively, and when it is possible to slow down.

Engineers at the Chernobyl nuclear power plant. 1980

In the early 1980s, the USSR began to slowly explore the possibility of rapidly increasing and decreasing the power of reactors. This method of controlling energy loads was, in theory, much simpler and more profitable than all the others.

This program, of course, was not discussed openly, the station personnel could only guess why these “scheduled repairs” became so frequent and the regulations for working with reactors changed. But, on the other hand, they didn’t do anything so extraordinarily vile with the reactors. And if this world was regulated only by the laws of physics and logic, then the fourth power unit would still behave like an angel and regularly serve the peaceful atom.

For so far, no one has been able to properly answer the main question of the Chernobyl disaster: why did the reactor power not fall after the introduction of the rods at that time, but, on the contrary, inexplicably increased sharply?

The two most authoritative bodies - the USSR Gosatomnadzor Commission and the IAEA Special Committee, after several years of work, gave birth to documents, each of which is crammed with facts about how the accident proceeded, but one cannot find an answer to the question “why?” on a single page in these detailed studies. There you can find wishes, regrets, fears, indications of shortcomings and forecasts for the future, but there is no clear explanation for what happened. By and large, both of these reports could be reduced to the phrase "Someone boomed there"*.

* Note Phacochoerus "a Funtik: « No, well, that's slander! The IAEA staff, however, expressed themselves more cultured. In fact, they wrote: “It is not known for certain how the power surge began, which led to the destruction of the reactor at the Chernobyl nuclear power plant. »

Less official researchers, on the contrary, put forward their versions with might and main - one more beautiful and more convincing than the other. And if there were not so many of them, one of them would probably be worth believing.

Various institutions, organizations and simply world-famous scientists in turn declared the perpetrators of the incident:

incorrect design of the rods; incorrect design of the reactor itself;
the error of personnel who reduced the power of the reactor for too long; a local unnoticed earthquake that occurred exactly under the Chernobyl nuclear power plant; ball lightning; still unknown to science particle, which sometimes occurs in a chain reaction.

The alphabet is not enough to list all the authoritative versions (non-authoritative ones, of course, as always, look more beautiful and contain such wonderful things as evil Martians, cunning cereushniks and an angry Jehovah. It is a pity that such a respected scientific publication as MAXIM cannot go on about the low tastes of the crowd and with gusto to describe all this in more detail.

These strange methods of dealing with radiation

The list of items that are usually required to be distributed to the public in the event of a radiation hazard seems incomplete to the uninitiated. And where is the button accordion, boa and net? But in fact, the things on this list are not so useless.

Mask Someone seriously believes that gamma rays, instantly penetrating steel, will save in front of five layers of gauze? Gamma rays are not. But the radioactive dust, on which the heaviest ones have already settled, but no less dangerous substances, will be less intensively inhaled.

Iodine The isotope of iodine - one of the shortest living elements of a radioactive release - has the unpleasant property of settling in the thyroid gland for a long time and making it completely unusable. Tablets with iodine are recommended to be taken so that your thyroid gland of this iodine is filled up and it no longer grabs it from the air. True, an overdose of iodine is a dangerous thing in itself, so it is not recommended to swallow it in vials.

canned food Milk and vegetables would be the most useful foods when exposed to radiation, but alas, they are the first to become infected. And then comes the meat, which ate vegetables and gave milk. So it is better not to collect pasture in the infected region. Especially mushrooms: they contain a concentration of radioactive chemical elements uppermost.

liquidation

Recording of rescue dispatchers' conversations immediately after the disaster:

The explosion itself claimed the lives of two people: one died immediately, the second was taken to the hospital. Firefighters were the first to arrive at the scene of the disaster and set to work - extinguishing the fire. They extinguished it in canvas overalls and helmets. They had no other means of protection, and they did not know about the radiation threat - only after a couple of hours information began to spread that this fire was somehow different from the usual one.

By morning, firefighters put out the flames and began to faint - radiation damage began to affect. 136 employees and rescuers who found themselves at the station that day received a huge dose of radiation, and one in four died in the first months after the accident.

In the next three years, a total of about half a million people were engaged in the elimination of the consequences of the explosion (almost half of them were soldiers military service, many of whom were actually sent to Chernobyl by force). The very site of the disaster was covered with a mixture of lead, boron and dolomites, after which a concrete sarcophagus was erected over the reactor. Nevertheless, the amount of radioactive substances released into the air immediately after the accident and in the first weeks after it was enormous. Neither before nor after have such numbers been found in densely populated areas.

The deafening silence of the Soviet authorities about the accident did not then seem as strange as it is now. Hiding bad or exciting news from the population was so common practice at that time that even information about a sex maniac operating in the area could not reach the ears of a serene public for years; and only when the next "Fischer" or "Mosgaz" began to count their victims by tens, or even hundreds, the district police officers were given the task to quietly bring to the attention of parents and teachers the fact that it would probably be better for the kids not to run alone along the street.

Therefore, the city of Pripyat was evacuated the next day after the accident hastily, but quietly. People were told that they were being taken out for a day, a maximum of two, and they were asked not to take any things with them so as not to overload the transport. The authorities did not say a word about radiation.

Rumors, of course, spread, but the vast majority of the inhabitants of Ukraine, Belarus and Russia have never heard of any Chernobyl. Some of the members of the Central Committee of the CPSU had the conscience to raise the issue of canceling the May Day demonstrations, at least in cities located directly in the path of polluted clouds, but it was considered that such a violation of the eternal order would cause unhealthy unrest in society. So the residents of Kiev, Minsk and other cities managed to run around with balloons and carnations under the radioactive rain.

But a radioactive release of this magnitude was impossible to hide. The Poles and Scandinavians were the first to raise the cry, to which those same magical clouds flew in from the east and brought with them a lot of interesting things.

indirect evidence that scientists gave the government is kind to keep silent about Chernobyl, the fact that scientist Valery Legasov, a member of the government commission investigating the accident, who organized the liquidation for four months and voiced the official (very smoothed) version of what was happening to the foreign press, hanged himself in 1988, leaving a voice recorder in his office the record telling about the details of the accident, and that part of the record, where chronologically there should have been a story about the reaction of the authorities to the events in the first days, turned out to be erased by unidentified persons.

Another indirect evidence of this is that scientists still radiate optimism. And now officials federal agency on atomic energy stand on the fact that only those several hundred people who took part in the liquidation in the first days of the explosion, and even then with banknotes, can be considered really affected by the explosion. For example, the article “Who Helped Create the Chernobyl Myth”, written by experts from the FAAE and IBRAE RAS in 2005, analyzes statistics on the health status of residents of contaminated areas and, recognizing that, in general, the population there gets sick a little more often, sees the reason only in the fact that, succumbing to alarmist moods, people, firstly, run to the doctors with every pimple, and secondly, for many years they have been living in unhealthy stress caused by hysteria in the yellow press. They explain the huge number of disabled people among the liquidators of the first wave by the fact that “being disabled is beneficial”, and hint that the main cause of catastrophic mortality among the liquidators is not the consequences of exposure, but alcoholism, caused by the same irrational fear of radiation. Even the phrase "radiation danger" is written by our peaceful nuclear scientists exclusively in quotation marks.

But this is one side of the coin. For every nuclear worker who is convinced that there is no cleaner and safer energy in the world than atomic energy, there is a member of an environmental or human rights organization who is ready to sow that same panic in generous handfuls.

Greenpeace, for example, estimates the number of victims of the Chernobyl accident at 10 million, adding to them, however, representatives of the next generations who will fall ill or be born sick within the next 50 years.

Between these two poles there are tens and hundreds international organizations, statistical studies of which contradict each other so much that in 2003 the IAEA was forced to create the Chernobyl Forum organization, whose task would be to analyze these statistics in order to create at least some reliable picture of what is happening.

And so far, there is nothing clear with estimates of the consequences of the disaster. The increase in mortality of the population from areas close to Chernobyl can be explained by the mass migration of young people from there. A slight "rejuvenation" of oncological diseases - by checking local residents for oncology much more intensively than in other places, so many cases of cancer are caught at very early stages. Even the condition of burdocks and ladybugs in the closed zone around Chernobyl is the subject of fierce disputes. It seems like the burdocks grow amazingly juicy, and the cows are well-fed, and the number of mutations in the local flora and fauna is within the natural norm. But what is the harmlessness of radiation here, and what is the beneficial effect of the absence of people for many kilometers around, it is difficult to answer.

04/26/1986 at the Chernobyl nuclear power plant, in the 4th power unit, an explosion occurred great strength, as a result of which the nuclear reactor was completely destroyed. This sad event went down in the history of mankind forever as the "accident of the century".

Explosion at the Chernobyl nuclear power plant. Year 1986, April 26 - a black date in history

The most powerful nuclear power plant in the USSR has become a source of extremely dangerous pollutants in environment, because of which 31 people died within the first 3 months, and the number of deaths over the next 15 years exceeded 80. The most severe consequences of radiation sickness were recorded in 134 people due to powerful radioactive contamination. A terrible "cocktail" consisted of a large list of elements of the periodic table, such as plutonium, cesium, uranium, iodine, strontium. Deadly substances mixed with radioactive dust covered a huge territory with a mud plume: the European part of the Soviet Union, eastern part Europe and Scandinavia. Belarus has suffered greatly from the polluted precipitation. The explosion of the Chernobyl nuclear power plant was compared with the nuclear bombings of Hiroshima and Nagasaki.

How the explosion happened

During the investigation, numerous commissions analyzed this event more than once, trying to find out what exactly caused the disaster and how it happened. However, there is no consensus on this matter. A force capable of destroying all life in its path broke out of the 4th power unit. The accident was classified: the Soviet media kept deathly silence for the first days, but the explosion at the Chernobyl nuclear power plant (year 1986) was recorded abroad due to a colossal radiation leak and raised the alarm. It became impossible to keep silent about the accident. The energy of a peaceful atom was intended to move civilization forward, towards progress, but it changed its trajectory and caused an invisible war of man with radiation.

The explosion at the Chernobyl nuclear power plant, the date of which will be remembered by mankind for centuries, began with a fire in power unit No. 4, the signal of which was received by the control panel at 1.24 am. The fire brigade promptly started extinguishing, having successfully coped with the fire by 6 o'clock in the morning, thanks to which the fire could not spread to block No. 3. The level of radiation in the territory of the halls of the power unit and near the station at that time was unknown to anyone. What happened during these hours and minutes with nuclear reactor, was also unknown.

Reasons and official versions

Analyzing the explosion at the Chernobyl nuclear power plant, the causes of which were inexplicable at first glance, experts put forward many versions. Summing up the results of the investigation, the scientists settled on several options:

1. Violation and disruption of the operation of circular pumps due to cavitation (the formation of a shock wave as a result of chemical reaction) and, as a result, a pipeline break.
2. Power surge inside the reactor.
3. Low level enterprise security - version INSAG.
4. Emergency acceleration - after pressing the "AZ-5" button.

The latter version, according to many experts in the industry, is the most plausible. In their opinion, the control and protection rods were activated by active work precisely by pressing this ill-fated button, which led to an emergency runaway of the reactor.

This course of events is completely refuted by experts from the Gospromatomnadzor commission. Employees put forward their versions of the causes of the tragedy back in 1986, insisting that the positive reactivity was caused by the emergency protection that worked, which caused the explosion of the Chernobyl nuclear power plant.

Certain technical calculations that prove the cause of the explosion due to cavitation on the anti-aircraft missile system refute other versions. According to the chief designer of the Chernobyl NPP, the steam at the reactor inlet, as a result of the boiling of the coolant in the air defense system, got into the core and distorted the energy-releasing fields. This happened due to the fact that the temperature of the coolant in the most dangerous period reached the boiling point. Emergency acceleration began precisely with active vaporization.

The explosion of the Chernobyl nuclear power plant. Other causes of the tragedy

In addition, opinions were often heard about such a cause of the explosion as a sabotage action, which was planned by the United States and carefully hidden by the Soviet government. This version is supported by photographs of an exploded power unit from an American military satellite, which miraculously ended up in the right place exactly when the explosion at the Chernobyl nuclear power plant occurred. It is very difficult to refute or confirm this theory, and therefore this version remains a guess. It remains only to confirm that in 1986 the explosion of the Chernobyl nuclear power plant actually resulted in the disabling of secret facilities (Over-the-horizon radar station Duga-1, Chernobyl-2).

Among the causes of the tragedy are also called the earthquake that occurred at that moment. Indeed, shortly before the explosion, seismographs recorded a certain shock in the immediate vicinity of the Chernobyl nuclear power plant. It is the vibration that could provoke an accident that the adherents of this version call the reason for launching irreversible processes. In this situation, the fact that the neighboring power unit No. 3 for some reason did not suffer in any way and did not receive information about seismic tremors looks strange in this situation. But it hasn't been tested yet...

The most fantastic cause of the explosion was also put forward - this is a possible ball lightning, formed during the bold experiments of scientists. It was she, if we imagine such a course of events, that could well disrupt the operation in the reactor zone.

The consequences of the tragedy in numbers

At the time of the explosion itself, only 1 person died at the station. The very next morning, another employee died from very serious injuries. However, the worst began later, when 28 more people died literally within a month. They and 106 other employees of the station were at work at the time of the disaster and received the maximum dose of radiation.

Fire suppression

To extinguish the fire, when a fire was announced in the Chernobyl power unit No. 4, 69 employees of the fire brigade, as well as 14 vehicles, were involved. People put out the fire, not having any idea about the highest level pollution. The fact is that it was impossible to look at the radiation background metering devices: one was faulty, the second remained out of reach, under the rubble. That is why no one could even imagine the real consequences of the explosion at that time.

Year of death and sorrow

At about 2 am, some firefighters developed the first symptoms of radiation sickness (vomiting, weakness, and an incomparable "nuclear tan" on the body). After the first medical care patients were taken to the city of Pripyat. The next day, 28 people were urgently sent to Moscow (6th Radiological Hospital). All the efforts of the doctors were in vain: the fire tamers received such a large infection that they died within a month. From the huge release of radioactive substances into the atmosphere during the catastrophe, trees also died on an area of ​​​​almost 10 square meters. km. The explosion at the Chernobyl nuclear power plant, the consequences of which were felt not only by the direct participants, but also by the inhabitants of the three republics of the Soviet Union, forced unprecedented security measures to be taken at all similar installations.

30 years ago, on April 26, 1986, the fourth reactor of the Chernobyl Nuclear Power Plant (ChNPP) exploded. Now, 30 years after the tragedy, the attention of politicians, ecologists and engineers is riveted to an unprecedented construction project - the construction of the New Safe Confinement (NSC) instead of the Shelter object, which for the next hundred years should solve the problem of radiation safety around the destroyed 4- th reactor. Funds for this project, which should be completed in 2017, were raised by the whole world.

Close the station without donors

Meanwhile, another most difficult task remains in the shadows, with which Ukraine found itself face to face. The decommissioning of the Chernobyl nuclear power plant is a complex and costly process. Its total cost is estimated at four billion dollars. However, due to insufficient funding, the process is delayed.

"Last year we received more than 700 million hryvnia (27.5 million euros) from the state budget. Every year, we are given about 60 percent of the funds that we ask for in order to carry out decommissioning work in accordance with the schedule," - Viktor Kuchinsky, head of the strategic planning service at the Chernobyl nuclear power plant, told DW.

He, as one of the most experienced specialists at the plant, manages the decommissioning process. In conditions of a chronic shortage of funds, it is possible to fulfill the work schedule by more than 80 percent and fully ensure safety for the population, Kuchinsky assures.

The last - the third - power unit of the Chernobyl nuclear power plant ceased to produce electricity in December 2000. More than 15 years passed before the specialists completed the removal of spent nuclear fuel from all power units of the station. “There are only a few dozen builds left, we will unload them in the first half of this year,” Kuchinsky says. According to him, we are talking about corrupted assemblies, for the extraction of which it was necessary to look for a special technical solution and develop a separate technology.

The next step is preservation.

Now the nuclear power plant is finally moving on to the main stage of its decommissioning. With the completion of the extraction of fuel, the power units will lose the status of nuclear installations and will be recognized as objects intended for the management of radioactive waste. “Last year, we received permission from state regulatory authorities to begin the main stage of decommissioning the plant. It is called the “final closure and conservation stage,” Viktor Kuchinsky explains.

The main task of this stage is to reliably mothball the first, second and third reactors with the most contaminated equipment. This stage, however, will drag on for more than ten years. There are a number of reasons for this, lack of funds is not the only one. There are still many technical problems.

One of them is typical for RBMK type reactors: it is the handling of the graphite lining of the reactor core. Scientists still haven't found a way to safely extract graphite from a reactor. "We hope that before 2045, when it is planned to start dismantling the reactors, a technology for handling graphite will be found," Chernobyl Deputy Director General Valery Seyda told DW.

Viktor Kuchinsky adds that another key issue that significantly affects the duration of the decommissioning process is the lack of necessary infrastructure, in particular secure temporary and permanent storage facilities for nuclear fuel and radioactive waste.

The new storage facility will be built by the end of 2016.

Spent fuel from the Chernobyl reactors was delivered to the one built back in Soviet time wet storage. Several tens of thousands of fuel assemblies are stored here. "The water in which the fuel assemblies are located is a neutron moderator. The assemblies are located at a safe distance from each other. But in the event of, for example, an earthquake, there may be problems. Therefore, all over the world they are switching to" dry "storage of spent fuel," explained Valery Seyda.

A "dry" storage near the Chernobyl nuclear power plant was planned to be built back in 2004. However, the contract with the French contracting company was terminated due to its failure to comply with the conditions and the non-compliance of the proposed technology with safety requirements. It is entrusted to complete the object American company Holtec.

Context

The lion's share of construction costs is financed by international donors. Work was previously promised to be completed by 2015. However, the commissioning date has recently been postponed again - to the end of 2016. According to the optimistic scenario, all the fuel from "wet" to a more reliable "dry" storage will be transported no earlier than in ten years.

Process for decades

The next generations of specialists will complete the process of decommissioning the plant. According to the schedule, this should happen in 2064. Until then, the reactors will remain mothballed until their radioactivity decreases. Thus, closing the station will take three times as long as it was in operation.

More than two thousand people still work at the Chernobyl nuclear power plant. This is three times less than twenty years ago. But this is still a lot for a plant that has not produced electricity for more than 15 years. A sharp reduction in staff is not expected in the coming years - there is still a lot of work ahead.

In 10-12 years, when, as planned, the Chernobyl nuclear power plant will be transferred to the long-term conservation mode, it will be necessary to start other works in parallel. Namely: the creation of safe storage facilities, in which the used equipment of the station will subsequently be placed. But all these works can be done only under one condition: if during the period of conservation it will be possible to accumulate sufficient funds for the costly process of dismantling the blocks.

See also:

• Exclusion Zone

  After the accident at the Chernobyl nuclear power plant, it became necessary to control the territories that were subjected to the greatest radioactive contamination - these are the cities of Chernobyl and Pripyat. The 30-kilometer zone around the station was closed to free access. Today, an enterprise for the management of the exclusion zone is located in Chernobyl, and up to 2,800 employees of enterprises building an arch for the sarcophagus also live there.



Chernobyl zone 30 years after the tragedy

In the 1970s, the construction of the first nuclear power plant in Ukraine began in the Chernobyl region. Chernobyl is located 3 km from the city of Pripyat and 18 km from the city of Chernobyl. It produced a tenth of the electricity in the Ukrainian SSR. The Chernobyl nuclear power plant was completely stopped only at the end of 2000. Currently, work continues on the construction of a new insulating structure above the fourth power unit.



Chernobyl zone 30 years after the tragedy

Chernobyl - the administrative center of the exclusion zone

Before the accident, 12.5 thousand people lived in Chernobyl, all of them were evacuated a few days after the tragedy. On the this moment the city is included in the 30-kilometer exclusion zone, being its administrative center. The personnel of the enterprises located here live in abandoned apartment buildings. When crossing the boundaries of the exclusion zone, everyone is required to undergo dosimetric control.



Chernobyl zone 30 years after the tragedy

Arch - a new shelter for the sarcophagus

More than 600 thousand people took part in the liquidation of the Chernobyl accident. Their main task was the construction of a concrete sarcophagus for the 4th power unit. Under the influence of external factors and radiation, the old shelter began to collapse, which is dangerous - about 200 tons of radioactive substances are still stored there. The new arched structure should cover the sarcophagus and allow its partial dismantling to begin.



Chernobyl zone 30 years after the tragedy

"Samosely" in the exclusion zone

Until now, the concentration of radionuclides in the exclusion zone is high, which does not allow lifting restrictions on living there. However, soon after the accident and evacuation, local residents began to return to their homes under various pretexts. These people were called "self-settlers". To date, there are about 180 of them in the zone: 80 in Chernobyl and about 100 more in villages located within a 30-kilometer zone.



Chernobyl zone 30 years after the tragedy

Grocery store twice a month

Mostly "self-settlers" are elderly people. They now live in four villages of the 30-kilometer exclusion zone. "Samosely" grow vegetables and fruits, pick mushrooms in the forest and drink water from wells. Of the benefits of civilization, they have only electricity. A grocery truck with bread and cereals comes twice a month, and once a month the postman delivers pensions.



Chernobyl zone 30 years after the tragedy

Pripyat - a ghost town

The city of Pripyat is located on the banks of the river of the same name, 3 km from the Chernobyl nuclear power plant. It was he who was subjected to the greatest radioactive contamination. The population of the city of Pripyat was 47.5 thousand people, the day after the accident they were all evacuated. Even after the decontamination works, the radiation level is too high, so the city is uninhabitable.



Chernobyl zone 30 years after the tragedy

Secret object "Duga-1"

The secret object "Duga-1" is a Soviet-era radar station designed to detect launches of intercontinental ballistic missiles. "Duga-1" never fully took up combat duty. The size of the structure of many antennas is 700 m in length and 150 m in height. After the accident at the Chernobyl nuclear power plant, the facility was mothballed, later its main elements were dismantled and taken away.



Chernobyl zone 30 years after the tragedy

"Death Bucket"

The so-called "death bucket" is one of the current attractions of the city of Pripyat. The bucket was used during the liquidation of the consequences of the accident directly at the 4th power unit of the Chernobyl nuclear power plant. Radiation from the ladle (even a few meters from it) exceeds the norm by ten thousand times. It is forbidden to touch him.



Chernobyl zone 30 years after the tragedy

The city of Pripyat was built as an exemplary one; during its construction, innovative architectural solutions for those years were used. At the time of the evacuation in 1986, Pripyat had 15 kindergartens, 5 schools, swimming pools, canteens, sports complexes, clinics, a cinema and a palace of culture. Now there is almost nothing left of the city: the roads are overgrown, in many buildings the internal partitions have collapsed.



Chernobyl zone 30 years after the tragedy

Dead ground

Pripyat was to become the most beautiful, exemplary city of Soviet Ukraine. But it went down in history as a city-monument to the most terrible nuclear disaster in the world. At the moment, in Pripyat there is only a special laundry, a water fluoridation and iron removal station and a garage for Chernobyl special equipment. Not a single person lives in the city.



Chernobyl zone 30 years after the tragedy

Extreme tourism zone

Every year, the exclusion zone is visited by several thousand extreme tourists. Before the start of the conflict in eastern Ukraine, citizens of Russia were in the lead among foreign tourists. Today, most of the guests are from Poland, the Czech Republic and the USA.