Accidents at nuclear power plants. Accident at the Chernobyl nuclear power plant: causes, liquidators, consequences

Expand the topic of the Chernobyl disaster (as the biggest accident at nuclear power plants) and its consequences are impossible without understanding what the whole region was before the tragic accident. Therefore, this article should begin with the history of the Chernobyl district of the Kiev region, or rather, even with the history of the town of Chernobyl. The accident at the nuclear power plant has firmly linked this city with anthropogenic catastrophe, but the first mention of it dates back to the 15th century (in Lithuanian sources), and it has its own centuries-old history.

History of Chernobyl and its surroundings

During the colonization of Ukrainian lands by Polish tycoons in the 16th century, a huge castle was erected in the vicinity of Chernobyl, from which only the moat survived to this day. Chernobyl itself (as a remote city from the capital of the Commonwealth) was populated mainly by Jews, thanks to which it became one of the centers of Hasidism (one of the currents of Judaism) after settling in the place of the dynasty of Hasidic rabbis Menachem Tversky. After the entry of Chernobyl into the Russian Empire, the Ukrainian culture began to develop in the town, Chernobyl became the center of the Ukrainian song of the Northern Polesye. During the Nazi occupation the city ceased to be the center of Jewish life for understandable reasons. After the war in Chernobyl, the period of industrial development began. The town acquired the status of a city, and its population grew.

Thus, Chernobyl existed long before the accident at the Chernobyl nuclear power plant occurred. The city has long been associated not only with the nuclear power plant, but also was an industrial center, as well as a place for the development of Ukrainian and Jewish cultures.

Construction of the ChNPP and development of the region

In 1970, the first in the territory of modern Ukraine nuclear power plant was built in the Chernobyl region, named after the leader of the world proletariat V.I. Lenin. Of course, Vladimir Ilyich had nothing to do with the Chernobyl area, and Lenin himself was unlikely to be in these places. But since the Chernobyl nuclear power plant was actually built on a wasteland that was not famous for its famous events or outstanding people, it is true that the nuclear power plant built within the framework of the program for the development of nuclear energy in the Soviet Union, the course for which the CPSU Congress defined, was named after the most revered in the Soviet The state of man.

Ten kilometers to the nearest city - a long distance for the resettlement of employees of the power plant. Therefore, near the infamous Chernobyl nuclear power station, the town of Pripyat, a nuclear power plant, was founded, which in 1979 received the city status. The entire population of the city that has grown over a few years has been involved in a nuclear power plant, or it has served its employees in the city. The entire urban industry was aimed exclusively at ensuring the needs of nuclear power engineers and the station. At the time of the accident, the population of Pripyat reached almost 50 thousand people.

The city of Chernobyl itself does not have the slightest relation to the nuclear power station, except territorial proximity. He lived his life for more than one century. But it was the accident at the Chernobyl nuclear power plant, connected with the city only by territorial proximity, made it the center of attention of the world community.

The accident of 1986

In 1983 there was, as they say, the fourth power unit of the Chernobyl NPP was built in a hurry. A few years earlier, Soviet scientists built a nuclear power plant in Iraq, which was destroyed from the air by Israeli Air Force fighters. This attack demonstrated the absolute defenselessness of the Soviet nuclear power industry before a sudden attack, so the Soviet atomic scientists began to think over how to provide electricity to the city and the village in case of a sudden attack on an atomic facility. To conduct experiments in this direction, the fourth power unit was built, concealing a number of shortcomings and defects in its construction.

On the night of April 26, 1986 an accident at the Chernobyl nuclear power plant occurred in the fourth power unit of the power plant. During the experiments with the reactor, two powerful explosions occurred that determined the further unenviable fate of the entire population of the many thousands of the city of Pripyat and its environs, including the cities of Chernobyl. The explosion was caused by overheating of the reactor, which tore off its lid and released a huge amount of radiation into the air.

Causes of the Chernobyl accident

The causes of the accident at the Chernobyl nuclear power plant are a controversial subject and to this day, many versions are being put forward, both admissible and absolutely fantastic. But there are two clear reasons for the unfolding events at the Chernobyl nuclear power station - political and technical.

Political reason

In the Soviet Union, undoubtedly, great attention was paid to education. Soviet universities produced highly qualified specialists in all branches of science and culture. But to advance the career ladder, the red diploma was of secondary importance, much more important was the success in political training, as well as the party's dedication to its high ideals. For this reason, the post of chief engineer of the ChNPP was received by an active and executive party worker, Nikolai Fomin, who was a specialist in the field of thermal power plants, but was completely ignorant of nuclear power. He practically did not interfere in the activities of his subordinates and fully trusted his deputy, Dyatlov, who was appointed to this post in the year of the accident at the Chernobyl nuclear power plant. Dyatlov was an experienced nuclear scientist, but he came to Pripyat specifically to conduct experiments with the reactor that were acceptable to the government on that fateful night. Fomin himself at that time quietly slept in his bed.

Both Dyatlov, Fomin, and the director of the Chernobyl nuclear power station had one common goal - to curry favor with their party leadership in order to rise higher up the career ladder. And Djatlov's subordinates who assisted him in the operator's room during the experiments, realizing the possible danger of manipulating the reactor, were afraid to disobey the orders of his immediate superiors, since dismissal threatened the nuclear workers with a move from warm Pripyat to the colder cities of nuclear scientists in Siberia.

Thus, one of the main reasons for the accident at the Chernobyl nuclear power plant was, on the one hand, the negligence of the station's top management, and on the other - the indecision of the personnel to refuse to carry out obviously dangerous management orders.

Technical reason

As already mentioned, on the night of the accident at the power plant, an experiment was conducted on orders from Moscow itself. The technical goal of the experiment was to completely stop the steam turbines of the power plant and to switch to electricity from generators at low reactor power. Thus, in theory, radiation leakage can be avoided during the bombing of a nuclear power plant, while continuing to provide electricity for some time.

To start the experiment, it was necessary to reduce the reactor power to 700 megawatts. But in the process of lowering the power of the reactor fell almost completely. According to the instruction, the atomic scientists were obliged to completely stop the reactor and only then to start it again. But Dyatlov wanted quick results, so he ordered his engineers to remove all the control rods from the reactor, providing control over the power, thereby causing a sharp rise in it. But shortcomings in the construction of the reactor led to the fact that the sensors on the control rods did not remove the temperature readings from the very bottom of the reactor, where after the removal of the rods the temperature began to rise sharply.

Not knowing this, based on the readings of the instruments, they continued the experiment at a power of 200 megawatts (in spite of the necessary 700) and stopped the turbine. Under the influence of high temperature, the water quickly evaporated, and the reactor began to overheat sharply, but the engineers learned about it too late, when the worker saw with his own eyes how steam lifts the regulating rods.

Realizing the danger of the situation, Dyatlov decided to start emergency reduction of reactor capacity. Technically this meant simultaneous maximum immersion of all control rods. In theory, this should lead to a rapid decrease in reactor temperature, but engineers did not take into account that the tips of the bromine rods contain graphite, which initially raises the reactor temperature for a short time. And since the rods fell simultaneously, the temperature of the reactor almost instantaneously increased tens of times, as a result of which the reactor could not stand the pressure and exploded.

Thus, the technical causes of the accident at the Chernobyl nuclear power plant are related to the reactor's shortcomings during its construction, as well as to the operators' error and violation of the regulations.

Evacuation of people and evaluation of consequences

Since the accident at the Chernobyl nuclear power plant occurred at night, the assessment of its consequences began only on the morning of April 27. Before that, only a few firefighters were sent to eliminate the fire that occurred as a result of the explosion. Even after the surface analysis and measurements of the radiation level in the air, which turned out to be more than 120 roentgens (at a rate of up to 20), it became clear the need for evacuation of people.

At that time, people were officially informed about the need for temporary evacuation to the nearby cities of the Kiev region. At that time, no one realized the scale of what had happened. In the city were identified places for evacuation, where the entire city bus fleet was brought. People were evacuated quickly, so the citizens were forced to leave everything they had earned by honest work in their homes, and much was even forbidden to be taken out because of the danger of radiation contamination.

Since the accident at the Chernobyl nuclear power plant occurred suddenly, in one day people lost almost everything: work, a roof over their heads, they made serious health problems, and many within a few years died of radiation sickness, lost their loved ones. But the consequences of the disaster were much larger than the Pripyat, and indeed the entire Chernobyl area. Radiation went to the west, raising the radiation background in Belarus and Central Europe. Even Sweden was complaining about rising radiation levels. But not every resident of Pripyat and nearby settlements left the contaminated zone. Some residents, strongly prikipevshie to their native places, remained in their homes. These people had to experience the reverse side of nuclear power.

Elimination of the accident

Despite the evacuation of people, it was impossible to leave the reactor that radiated harmful radiation as it is, moreover, it was completely impossible to completely stop the Chernobyl nuclear power plant immediately after the accident. Therefore, to liquidate the consequences, groups of liquidators were formed.

The liquidators of the accident at the Chernobyl nuclear power plant were recorded voluntarily. Among them there were both employees of the Ministry of Emergency Situations, and military, including emergency service, and indifferent civilians. The Soviet media broadcast about the security and modernity of nuclear energy, they insisted that the future was behind it. At that time, people who were ignorant of nuclear power did not realize the whole danger of the situation, because the liquidators of the accident at the Chernobyl nuclear power plant were willing to sincerely wish to help their compatriots.

Only then they realized how much they had undermined their health. One of the primary tasks of the liquidators was to fill the reactor. As a result, around the reactor, the liquidators built a sarcophagus, which was supposed to stop the further spread of radiation and give hope that once the Chernobyl region once again becomes habitable.

The radiation dose received by the liquidators killed many people for several years. Others became invalids, who need constant expensive medical care. The first liquidators immediately after their work were sent by plane to Moscow to the Institute of Radiation Diseases, the only one at that time in the Soviet Union. Some liquidators who got into this institute were saved. The rest received state subsidies in the form of pensions and benefits that have survived in independent Ukraine to the present day.

Consequences of the Chernobyl accident: creation of an exclusion zone

The consequences of the accident at the Chernobyl nuclear power plant were catastrophic. The entire Chernobyl district of the Kiev region was declared unfit for habitation, as a result of which it was liquidated and transferred to the jurisdiction of the Ivankov district of the Kiev region. The territory of the Chernobyl region was declared a zone of alienation. On the roads leading to the zone, checkpoints were installed, and the territory itself was eventually fenced for protection against marauders.

About the exclusion zone there are many rumors and legends, many alternative causes of accidents at nuclear power plants are sounded. The Chernobyl zone has repeatedly visited the center of attention of writers, journalists and creators of computer games. It also attracts photographers as the site of the accident at the nuclear power plant. Photos of such places, made in the post-apocalaptic style, attract the attention of not indifferent.

The theory that the Chernobyl zone contains secrets hidden by the government exists even today, despite the fact that control of entry into the zone is not so severe, and there are legal tourist excursions to Chernobyl.

Tourists from different countries are attracted to the city of Pripyat, which is a city-museum in which the Soviet era of the late eighties froze. Since then nothing has changed in it. The forests near Chernobyl, which became virgin clean, became a hunter's favorite place. And the ancient Chernobyl (the accident at the nuclear power plant affected it to a lesser extent) has about ten inhabitants who returned to their native places.

Directors were also interested in the accident at the Chernobyl nuclear power plant. The film "Moths", shot in Ukraine in 2013, has become a real masterpiece of cinematography, which allows the viewer to plunge into the world of experiences of people caught in the cycle of events of that time.

Consequences of the accident for the whole world. The reaction of the world community

Forced evacuation led to the irretrievable loss of the authentic culture of the Chernobyl region, whose inhabitants dispersed not only in the Kiev region, but throughout the country. The Soviet Union was forced to reconsider its attitude to nuclear power and its widespread use. Also, some historians believe that the consequences of the accident at the Chernobyl nuclear power plant have undermined the authority of the authorities in the eyes of the population.

The world, especially the capitalist public, politicized by the cold war, expressed a huge protest against the USSR in connection with the increase of its radiation background. Western media were full of articles about the inhumanity of the leadership of the Soviet state, that the consequences of accidents at nuclear power plants - the result of a secret experiment, which in fact was not so far from the truth. Especially sharply addressed to the Soviet Union was Japan, calling the Soviet scientists barbarians who can not be trusted with nuclear energy. Perhaps, the journalist who wrote this article revised his views after the accident at Fukushima.

Major accidents at nuclear power plants in the world

Although the Chernobyl disaster is considered to be the largest accident at nuclear power plants in the world, other equally serious incidents have occurred.

Accident at Three Mile Island

Seven years before the accident at the Chernobyl nuclear power plant, on March 28, 1979, an atomic accident occurred in the United States, at the Three Mile Island power plant in Pennsylvania. At that time, this accident was considered the largest in the world. The leakage of radiation occurred due to the breakdown of the heat-generating unit pipe.

Despite the scale of the accident at the nuclear power plant, the state authorities did not conduct forced evacuation, because they did not consider the accident dangerous. But children and pregnant women are still advised to temporarily leave the nearby city of Harrisburg. Actually, people left by themselves from nearby streets, fearing radioactive rays.

The nuclear power plant of Three Mile Island did not stop its work and continues to function today, being the largest American nuclear power plant.

Fukushima accident

Second place in the scale of the consequences (after the Chernobyl accident) is the accident at the Fukushima nuclear power plant located in the north-eastern part of Japan. The catastrophe happened on March 11, 2011. As a result of a strong earthquake of 9 points on the Richter scale , an 11-meter tsunami rose, waves of which flooded the power units of Fukushima-1. This caused a failure of the reactor cooling system and led to several hydrogen explosions in its core.

The accident at the Fukushima nuclear power plant caused a large-scale emission of radiation, which is 20 times greater than its Chernobyl counterpart. About 30,000 people received radiation contamination. Of course, it was only thanks to the timely reaction of the Japanese authorities and the readiness for emergency situations that the worst consequences were avoided, what caused the 1986 accident at the Chernobyl nuclear power plant. Nevertheless, according to forecasts of specialists, at least 20 years must pass before the consequences of the accident are completely neutralized. The catastrophe affected not only Japan, but also the western coast of the United States, in which, a few days after the explosion, there was also an increase in the radiation background.

In Japan, as in the USA, evacuation was not carried out, as modern nuclear power plant protection systems allow to quickly localize the source of the outflow, prevent the transformation of entire cities into deserted deserts. But nevertheless, Japan had to accept the increased level of radiation in food, water and air in the Fukushima prefecture, in close proximity to the emergency reactor. Sanitary standards for radiation levels for many products have been changed due to the fact that it was impossible to adhere to them.

Undoubtedly, nuclear energy is inexpensive and promising, but the operation of nuclear power plants requires increased caution, since the causes of accidents at nuclear power plants can be the most unexpected. But even if all the requirements are met, no one guarantees that someone's negligence or disgrace of nature will not cause the accident. And the consequences of accidents at nuclear power plants have to be eliminated for more than a decade. Therefore, even today the best minds of the world are thinking of creating powerful alternative nuclear power plants.