CONTENT
The beginning of the tragedy
Causes of the accident
liquidation
Effects
Sources
STARTING UP
At 01:23 an explosion occurred in the fourth power unit nuclear power plant in Chernobyl.
“But then something happened that even the wildest fantasy could not have predicted. 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.”
CAUSES
The Chernobyl disaster does not have one - the only reason. The catastrophe became possible as a result of a number of mistakes and miscalculations - political, managerial and technical.
- The danger of nuclear power was underestimated. This led to the decision to build nuclear power plants on a massive scale.
- When designing a nuclear power plant, a number of miscalculations were made.
- Low qualification and low discipline of personnel. The experiment, which failed during the day, was continued at night by young shift supervisors, in the absence of the main specialists of the station, which led to gross violation instructions (in particular, control rods were left in the working zone of the reactor much less than the critical norm.)
- In addition, untimely notification of people about the accident exacerbated the consequences and significantly increased the number of victims.
operator errors.
The most significant errors of operational personnel should be called:
- interpretation of the proposed tests as electrical
- inadequate preparation of the test program, including in terms of regulation of safety measures
- significant deviations from the program at the stage of preparation for the experiment and its implementation
- shutdown of safety systems, including emergency protection of the reactor
NPP operation scheme
L I K V I D A T I O
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 involved in the liquidation of the consequences of the explosion (almost half of them were conscripts, many of whom were sent to Chernobyl, in fact, 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.
EFFECTS
Emissions in environment
Isotopes of uranium
plutonium
Iodine - 131 (half-life - 8 days)
Cesium - 134 (half-life - 2 years)
Cesium - 137 (half-life 33 years)
Strontium - 190 (half-life - 28 years)
Impact of the accident on human health
The thyroid gland is one of the organs most at risk of cancer from radioactive contamination because it accumulates iodine-131; especially high risk for children
Between 1990 and 1998, more than 4,000 cases of thyroid cancer were reported among those under the age of 18 at the time of the accident.
Other diseases
Leukemia
congenital deformities
Cataract
Cardiovascular diseases
Decreased immunity
The number of children with Down syndrome born in Belarus in the 80s - 90s. The peak incidence of the disease occurs in January 1987.
Long-term effects and modernity
As a result of the explosion at the Chernobyl reactor, Ukraine suffered serious, long-term consequences. Because of the incident, many small towns and cities were buried forever - experts buried hundreds of small settlements with the help of heavy equipment. Due to the fact that the contamination due to the explosion spread to nearby areas, the government was forced to withdraw from agricultural circulation over 5 million hectares of land.
The radiation that spread far from the Chernobyl nuclear power plant hit, in particular, the Leningrad region, Chuvashia and Mordovia - in these areas, as well as in Belarus and European states, it fell in the form of precipitation. As a result of this catastrophe, an exclusion zone was formed around the Chernobyl nuclear power plant within a radius of 30 km, no one lives in these territories to this day.
In modern times, the Chernobyl nuclear power plant is not operated, however, many lovers of "black" tourism - the number of such people, according to travel companies, numbering in the tens of thousands. In the exclusion zone, in particular, in the city of Pripyat, it is allowed to stay for a short time, but tourists are prohibited from eating any food that is not brought from outside.
I S T O C N I C I
http://www.lib.ru/MEMUARY/CHERNOBYL/dyatlow.txt
https://ru.wikipedia.org/wiki/ Chernobyl
http://ria.ru/trend/chernobilskaya_katastrofa/
Target:
1. Consideration of the problem of using the atom for peaceful purposes and overcoming possible crisis moments.
2. Demonstration, using the example of Chernobyl, that man-made disasters are caused not only by a failure in technology, in mechanisms, but also by incorrect actions of personnel and other NPP employees
3. Development in students of a sense of responsibility for the fate of their country, their compatriots, understanding that each person must approach the performance of his work with high quality and seriously.
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GOU SOSH 1981 Moscow 25 years of the accident at the Chernobyl nuclear power plant Physics teacher Alikueva Elena Anatolyevna 2011
Chernobyl nuclear power plant Complete destruction of the Chernobyl reactor, Pripyat, Ukrainian SSR A radioactive cloud passed over the USSR, Eastern Europe, Scandinavia Chernobyl accident - April 26, 1986
Release to the environment Uranium isotopes Plutonium Iodine - 131 (half-life - 8 days) Cesium - 134 (half-life - 2 years) Cesium - 137 (half-life - 33 years) Strontium - 190 (half-life - 28 years)
Chronology of events At 1:23:39 - emergency protection signal (AZ-5) Then a signal of a rapid increase in power Recording systems fail Emergency protection rods stopped 1:23:47 - 1:23:50 (3 seconds!) - explosion , the reactor is completely destroyed
The hypothesized causes were: Hydrogen explosion - chemical nature of the explosion Thermal explosion - nuclear nature Steam explosion INSAG "...the accident was the result of an unlikely coincidence of a number of violations of rules and regulations operating personnel, the accident acquired catastrophic consequences due to the fact that the reactor was brought into an unscheduled state. Causes of the accident
Reactor deficiencies As of April 1986, the RBMK reactor had dozens of violations and deviations from the safety rules in force at that time. Due to the physical and design parameters of the active zone, erroneously chosen by its developers, the reactor was a system dynamically unstable with respect to the disturbance both in terms of power and steam content.
Operators' mistakes Thus, the most significant mistakes of the operational personnel should be called: interpretation of the proposed tests as electrical; improper preparation of the test program, including in terms of regulating safety measures; reactor emergency protection
Consequences of the accident
Informing the population
Elimination of the consequences of the accident
Impact of the accident on human health
Irradiation doses
Cancer The thyroid gland is one of the organs most at risk of developing cancer as a result of radioactive contamination, because it accumulates iodine-131; especially high risk for children Over 4,000 cases of thyroid cancer were reported between 1990 and 1998 among those under the age of 18 at the time of the accident
An increase in the number of congenital pathologies was found in various regions of Belarus between 1986 and 1994. Child mortality is very high in all three countries affected by the Chernobyl accident.
Other diseases Cataracts Cardiovascular diseases Decreased immunity
Dead city 25 years later
Memory of the dead
This must not happen again!
Chernobyl, a city in Ukraine, on the Pripyat River, at its confluence with the Kiev reservoir. Regional center with a developed industry: an iron foundry and a cheese-making plant, a repair and maintenance base for the fleet; workshop of production and art association, medical school.
On April 25, 1986, the shutdown of the 4th power unit of the Chernobyl nuclear power plant was scheduled for the next scheduled preventive maintenance. During such shutdowns, various routine procedures and equipment tests are usually carried out.
At about 1:24 am on April 26, 1986, a release occurred at the 4th power unit of the Chernobyl nuclear power plant, which completely destroyed the reactor. The building of the power unit partially collapsed, killing 2 people.
A fire broke out in various rooms and on the roof. Subsequently, the remnants of the core melted. As a result of the accident, radioactive substances were released into the environment.
The accident is regarded as the largest of its kind in the history of nuclear power, both in terms of the estimated number of people killed and affected by its consequences, and in terms of economic damage. At the time of the accident, the Chernobyl nuclear power plant was the most powerful in the USSR. The real number of deaths during the first 3 months is estimated at 31 people; the long-term effects of exposure, identified over the next 15 years, caused the death of 60 to 80 people.
Unlike the bombings of Hiroshima and Nagasaki, the explosion resembled a very powerful "dirty bomb" - radioactive contamination became the main damaging factor. The radioactive cloud from the accident passed over the European part of the USSR, Eastern Europe and Scandinavia. Approximately 60% of radioactive fallout fell on the territory of Belarus. About 200,000 people were evacuated from contaminated areas.
evacuation
About 50,000 people were evacuated from the city of Pripyat alone in one day.
In the first days after the accident, the population of the 10-kilometer zone was evacuated. In the following days, the population of other settlements of the 30-kilometer zone was evacuated. It was forbidden to take things with you, many were evacuated in home clothes. In order not to fan the panic, it was reported that the evacuees would return home in three days. Pets were not allowed to be taken with them (later they were shot).
While all foreign funds mass media they talked about the threat to people's lives, and a map of air flows in Central and Eastern Europe was shown on TV screens, festive demonstrations and festivities dedicated to May Day were held in Kyiv and other cities of Ukraine and Belarus. Those responsible for withholding information subsequently explained their decision by the need to prevent panic among the population.
Elimination of the consequences of the accident
On April 26, 1986, at 1:24 am, two explosions were heard in succession at the 4th power unit of the Chernobyl nuclear power plant, which announced to the whole world about the accomplished tragedy of the outgoing century. There was a powerful man-made disaster at a nuclear facility.
- The explosions led to the complete destruction of the reactor and its core, cooling systems, and the building of the reactor hall.
- Reinforced concrete and metal structures, graphite blocks and their pieces were thrown onto the roof of the turbine hall, into the area around the nuclear power plant.
- From the mouth of the reactor rose, several hundred meters high, a column of combustion products, a powerful stream of gaseous radioactivity. Of the 190 tons of nuclear fuel, 90% got into the earth's atmosphere. According to scientists, the release of radionuclides is, according to various estimates, four or more explosions in Hiroshima.
There is no roof, part of the wall is destroyed ... The lights went out, the phone turned off. Coverings are crumbling. Paul is trembling. The rooms are filled with either steam, or fog, dust. Short circuit sparks flash. Radiation control devices go off scale. Hot radioactive water flows everywhere.
At 1:30 a.m., divisions of fire departments for the protection of the nuclear power plant, the station itself and the city of Pripyat arrived at the crash site, under the command of lieutenants Viktor Kibenok (left) and Vladimir Pravik. Firefighters took on the full power of radioactive radiation when extinguishing a fire on the roof of the engine room. Later, fire brigades arrived from Chernobyl, Kyiv and other regions, commanded by Major Telyatnikov. By 5 o'clock in the morning the fire was localized
Both and their subordinates received high doses of radiation, they could not be saved.
Both were awarded the title of Hero Soviet Union posthumously. All of them are buried at the Mitinsky cemetery in Moscow.
As a result of the accident, it was decided to evacuate all settlements in the area of 30 kilometers. The city of Pripyat, with a population of more than 50,000 people, was also included in this list.
Today, thirty years later, the city is empty.
Thousands of people from all over former USSR were called up and sent to eliminate the consequences of the disaster. Work on the liquidation of the accident was carried out mainly manually.
They removed the top layer of soil on the territory of the nuclear power plant with shovels, threw pieces of reinforcement, graphite from the roof of the turbine hall with their hands, washed off the radioactive dirt with rags inside the station.
Some radio-controlled mechanisms that perform work to remove blockages could not withstand the high level of radiation and went out of control of the operators
The destroyed core had contact with the atmosphere; there everything was gurgling, noisy, buzzing, like fiery hell
The government, after listening to the advice of experts, decided to close, fill the funnel with heat-absorbing materials capable of filtering fire and ash.
Therefore, from April 27 to May 10, pilots Air force The USSR, risking their flesh and life, made hundreds of flights over the active zone. They dropped from helicopters thousands and thousands of bags of sand, clay, dolomite, boron, as well as large packages of lead, which ranked first in weight - 2,400 tons.
Deactivation It was important to prevent the expansion of the zone of radioactive contamination. To this end, they fought against dust formation, spraying the surface with a special mixture, used polymer coatings, used the vacuum suction cleaning method (vacuum cleaners), manually wiped objects with cloths soaked in decontaminating solutions.
Hundreds of vehicles were involved in extinguishing the reactor, ranging from firefighters to helicopters.
As a result of a large radioactive background, most of the cars were contaminated with radiation. A special parking lot was made for them, which has survived to this day.
On the tenth day, the emission power fell -
up to one percent. There was a nervous breakdown.
In the first days, when the eruption was in full swing, air currents moved to Belarus…
Its height was 61 meters, the greatest thickness of the walls -
18 meters. The erection of the "sarcophagus" was carried out with the help of self-propelled cranes equipped with television surveillance equipment. It provides for an exhaust ventilation system with air purification, a forced cooling system, and tanks with a boron solution are installed on the roof to prevent an increase in neutron activity.
"Rossokha" - a huge field filled with rows of corroded trucks, fire trucks, bulldozers, armored personnel carriers and other radioactive equipment - and in the middle, as a symbol of complete hopelessness, helicopters drooped with their blades, which will never again be destined to take to the air ...
Under the influence of radiation, apples grew incredible sizes
Foal with five limbs
30 years ago there was an accident at the Chernobyl nuclear power plant….
novosibirsk
Iskitim, Novosibirsk region
By the May holidays, everything was ready with the windows described by slogans, the scenarios for the demonstrations had already been submitted for approval by the authorities, in the restaurants they were compiling holiday menu. Everyone was anxiously waiting for 3 days off. Dreams about the holidays collapsed on April 26, when a terrible explosion at the Chernobyl nuclear power plant thundered, changing the lives of all the inhabitants of this youngest and most beautiful city in the USSR. Today it is an exclusion zone, from the very name of which, goosebumps go. The city is surrounded by barbed wire and entry is allowed only with passes ... By the May holidays, everything was ready for the shop windows described with slogans, the scenarios for the demonstrations had already been submitted for approval by the authorities, and the festive menu was being prepared in restaurants. Everyone was anxiously waiting for 3 days off. Dreams about the holidays collapsed on April 26, when a terrible explosion at the Chernobyl nuclear power plant thundered, changing the lives of all the inhabitants of this youngest and most beautiful city in the USSR. Today it is an exclusion zone, from the very name of which, goosebumps go. The city is surrounded by barbed wire and entry is allowed only with passes...
Chernobyl accident - the destruction on April 26, 1986 of the fourth power unit of the Chernobyl nuclear power plant, located on the territory of Ukraine (at that time the Ukrainian SSR). The destruction was explosive, the reactor was completely destroyed, and a large amount of radioactive substances was released into the environment. The accident is regarded as the largest of its kind in the history of nuclear power, both in terms of the estimated number of people killed and affected by its consequences, and in terms of economic damage. At the time of the accident, the Chernobyl nuclear power plant was the most powerful in the USSR. The real number of deaths during the first 3 months is estimated at 31 people; the long-term effects of exposure, identified over the next 15 years, caused the death of 60 to 80 people. Chernobyl accident - the destruction on April 26, 1986 of the fourth power unit of the Chernobyl nuclear power plant, located on the territory of Ukraine (at that time the Ukrainian SSR). The destruction was explosive, the reactor was completely destroyed, and a large amount of radioactive substances was released into the environment. The accident is regarded as the largest of its kind in the history of nuclear power, both in terms of the estimated number of people killed and affected by its consequences, and in terms of economic damage. At the time of the accident, the Chernobyl nuclear power plant was the most powerful in the USSR. The real number of deaths during the first 3 months is estimated at 31 people; the long-term effects of exposure, identified over the next 15 years, caused the death of 60 to 80 people.
As a result of the explosion at the Chernobyl nuclear power plant, an area of 4000 sq. km was cordoned off. The city of Pripyat and all settlements within a radius of 30 km were completely evacuated. But some who did not accept life in a foreign land returned immediately ... As a result of the explosion at the Chernobyl nuclear power plant, the territory with an area of 4000 sq. km. The city of Pripyat and all settlements within a radius of 30 km were completely evacuated. But some who did not reconcile themselves to life in a foreign land returned immediately ...
At about 1:24 am on April 26, 1986, a release occurred at the 4th power unit of the Chernobyl nuclear power plant, which completely destroyed the reactor. The building of the power unit partially collapsed, killing 2 people, the operator of the MCP pumps (Main circulation pump) Valery Khodemchuk (the body was not found, heaped under the debris of two 130-ton drum separators), and Vladimir Shashenok, an employee of the commissioning enterprise (died of a fracture of the spine and numerous burns at 6:00 in the Pripyat Medical Unit, on the morning of April 26). A fire broke out in various rooms and on the roof. Subsequently, the remnants of the core melted. A mixture of molten metal, sand, concrete and fuel particles spread over the sub-reactor rooms. As a result of the accident, radioactive substances were released into the environment, including isotopes of uranium, plutonium, iodine-131 (half-life 8 days), cesium-134 (half-life 2 years), cesium-137 (half-life 33 years), strontium -90 (half-life 28 years). At about 1:24 am on April 26, 1986, a release occurred at the 4th power unit of the Chernobyl nuclear power plant, which completely destroyed the reactor. The building of the power unit partially collapsed, killing 2 people, the operator of the MCP pumps (Main circulation pump) Valery Khodemchuk (the body was not found, heaped under the debris of two 130-ton drum separators), and Vladimir Shashenok, an employee of the commissioning enterprise (died of a fracture of the spine and numerous burns at 6:00 in the Pripyat Medical Unit, on the morning of April 26). A fire broke out in various rooms and on the roof. Subsequently, the remnants of the core melted. A mixture of molten metal, sand, concrete and fuel particles spread over the sub-reactor rooms. As a result of the accident, radioactive substances were released into the environment, including isotopes of uranium, plutonium, iodine-131 (half-life 8 days), cesium-134 (half-life 2 years), cesium-137 (half-life 33 years), strontium -90 (half-life 28 years). Graphite, metal and nuclear fuel What happened after the explosion...
In the first days after the accident, the population of the 10-kilometer zone was evacuated. In the following days, the population of other settlements of the 30-kilometer zone was evacuated. It was forbidden to take things with you, many were evacuated in home clothes. In order not to fan the panic, it was reported that the evacuees would return home in three days. Pets were not allowed to be taken with them, subsequently, from among the military and local hunters, detachments were formed to shoot abandoned domestic animals, as well as wild animals. In the first days after the accident, the population of the 10-kilometer zone was evacuated. In the following days, the population of other settlements of the 30-kilometer zone was evacuated. It was forbidden to take things with you, many were evacuated in home clothes. In order not to fan the panic, it was reported that the evacuees would return home in three days. Pets were not allowed to be taken with them, subsequently, from among the military and local hunters, detachments were formed to shoot abandoned domestic animals, as well as wild animals.
Until 2000, the 3rd power unit continued its work, currently 3,000 people are in the exclusion zone - ecologists, geologists and other specialists, 300 people out of these three thousand are residents who remained ... Until 2000, the 3rd power unit continued its work, currently, 3,000 people are in the exclusion zone - environmentalists, geologists and other specialists, 300 people of these three thousand are residents who remained ... Control panel 4 reactor 3rd power unit Corridor connecting control room 4, turbine hall and reactor shop.
Specialists sent to carry out work on the emergency unit and around it, as well as military units, both regular and composed of urgently called up reservists, began to arrive in the 30-kilometer zone around the Chernobyl nuclear power plant. All of them were later called "liquidators". The liquidators worked in the danger zone in shifts: those who had accumulated the maximum allowable dose of radiation left, and others came to take their place. The main part of the work was completed in years, about a person took part in them. The total number of liquidators (including subsequent years) amounted to about 30-kilometer zone around the Chernobyl nuclear power plant, specialists sent to carry out work on the emergency unit and around it, as well as military units, both regular and composed of urgently called up reservists, began to arrive. All of them were later called "liquidators". The liquidators worked in the danger zone in shifts: those who had accumulated the maximum allowable dose of radiation left, and others came to take their place. The main part of the work was completed in years, about a person took part in them. The total number of liquidators (including subsequent years) was about