On the night of April 26, 1986, at the fourth power unit of the Chernobyl nuclear power plant (ChNPP), located on the territory of Ukraine (at that time the Ukrainian SSR) on the right bank of the Pripyat River, 12 kilometers from the city of Chernobyl, Kyiv region, the largest accident in the history of world nuclear energy occurred .
The fourth power unit of the Chernobyl Nuclear Power Plant was put into commercial operation in December 1983.
On April 25, 1986, the Chernobyl Nuclear Power Plant was scheduled to conduct design tests of one of the safety systems at the fourth power unit, after which the reactor was planned to be shut down for scheduled repair work. During the tests, it was supposed to de-energize the nuclear power plant equipment and use the mechanical energy of rotation of stopping turbogenerators (the so-called run-down) to ensure the operation of the power unit’s safety systems. Due to dispatch restrictions, the shutdown of the reactor was delayed several times, which caused certain difficulties in controlling the reactor's power.
On April 26, at 01:24 a.m., an uncontrolled increase in power occurred, which led to explosions and destruction of a significant part of the reactor facility. Due to the explosion of the reactor and the subsequent fire at the power unit, a significant amount of radioactive substances was released into the environment.
Measures taken in the following days to fill the reactor with inert materials led first to a decrease in the power of radioactive release, but then an increase in temperature inside the destroyed reactor shaft led to an increase in the amount of radioactive substances released into the atmosphere. Radionuclide emissions decreased significantly only by the end of the first ten days of May 1986.
At a meeting on May 16, the government commission decided on the long-term conservation of the destroyed power unit. On May 20, the Ministry of Medium Engineering issued an order “On the organization of construction management at the Chernobyl nuclear power plant,” in accordance with which work began on the creation of the “Shelter” structure. The construction of this facility, involving about 90 thousand builders, lasted 206 days from June to November 1986. On November 30, 1986, by decision of the state commission, the mothballed fourth power unit of the Chernobyl nuclear power plant was accepted for maintenance.
The fission products of nuclear fuel released from the destroyed reactor into the atmosphere were carried by air currents over large areas, causing their radioactive contamination not only near nuclear power plants within the borders of Ukraine, Russia and Belarus, but also hundreds and even thousands of kilometers from the accident site. The territories of many countries have been exposed to radioactive contamination.
As a result of the accident, the territories of 17 European countries with a total area of 207.5 thousand square kilometers were exposed to radioactive contamination with cesium-137 with levels above 1 Ci/km2 (37 kBq/m2). The territories of Ukraine (37.63 thousand square kilometers), Belarus (43.5 thousand square kilometers), and the European part of Russia (59.3 thousand square kilometers) were significantly contaminated with cesium-137.
In Russia, 19 subjects were exposed to radiation contamination with cesium-137. The most polluted regions are Bryansk (11.8 thousand square kilometers of contaminated areas), Kaluga (4.9 thousand square kilometers), Tula (11.6 thousand square kilometers) and Oryol (8.9 thousand square kilometers).
About 60 thousand square kilometers of territories contaminated with cesium-137 with levels above 1 Ci/km 2 are located outside the former USSR. The territories of Austria, Germany, Italy, Great Britain, Sweden, Finland, Norway and a number of other Western European countries were contaminated.
A significant part of the territory of Russia, Ukraine and Belarus was contaminated at a level exceeding 5 Ci/km 2 (185 kBq/m 2). Agricultural land covering an area of almost 52 thousand square kilometers was affected by cesium-137 and strontium-90, with half-lives of 30 and 28 years, respectively.
Immediately after the disaster, 31 people died, and 600 thousand liquidators who took part in firefighting and cleanup received high doses of radiation. Almost 8.4 million residents of Belarus, Ukraine and Russia were exposed to radioactive radiation, of which almost 404 thousand people were resettled.
Due to the very high radioactive background after the accident, the operation of the nuclear power plant was stopped. After work on the decontamination of the contaminated area and the construction of the Shelter facility, the first power unit of the Chernobyl NPP was launched on October 1, 1986, the second on November 5, and the third power unit of the station was put into operation on December 4, 1987.
In accordance with the Memorandum signed in 1995 between Ukraine, the G7 states and the European Union Commission, on November 30, 1996, a decision was made to permanently shut down the first power unit, and on March 15, 1999, the second power unit.
On December 11, 1998, the Law of Ukraine “On the general principles of subsequent operation and decommissioning of the Chernobyl nuclear power plant and the transformation of the destroyed fourth power unit of this nuclear power plant into an environmentally safe system” was adopted.
The Chernobyl nuclear power plant stopped generating electricity on December 15, 2000, when the third power unit was permanently shut down.
In December 2003, the UN General Assembly supported the decision of the Council of Heads of State of the CIS to proclaim April 26 as the International Day of Remembrance for Victims of Radiation Accidents and Disasters, and also called on all UN member states to celebrate this International Day and hold relevant events within its framework.
The material was prepared based on information from RIA Novosti and open sources
April 26 is the Day of Remembrance for those killed in radiation accidents and disasters. This year marks 33 years since the Chernobyl disaster - the largest in the history of nuclear energy in the world. A whole generation has grown up without this terrible tragedy, but on this day we traditionally remember Chernobyl. After all, only by remembering the mistakes of the past can we hope not to repeat them in the future.
In 1986, an explosion occurred at Chernobyl reactor No. 4, and several hundred workers and firefighters tried to put out the fire, which burned for 10 days. The world was enveloped in a cloud of radiation. About 50 station employees were killed and hundreds of rescuers were injured. It is still difficult to determine the scale of the disaster and its impact on people’s health - only from 4 to 200 thousand people died from cancer that developed as a result of the received dose of radiation. Pripyat and the surrounding areas will remain unsafe for human habitation for several centuries.
1. This 1986 aerial photo of the Chernobyl Nuclear Power Plant in Chernobyl, Ukraine, shows the damage from the explosion and fire of reactor No. 4 on April 26, 1986. As a result of the explosion and fire that followed it, a huge amount of radioactive substances was released into the atmosphere. Ten years after the world's worst nuclear disaster, the power plant continued to operate due to severe power shortages in Ukraine. The final shutdown of the power plant occurred only in 2000. (AP Photo/Volodymyr Repik) 
2. On October 11, 1991, when the speed of turbogenerator No. 4 of the second power unit was reduced for its subsequent shutdown and removal of the SPP-44 steam separator-superheater for repair, an accident and fire occurred. This photo, taken during a journalists' visit to the plant on October 13, 1991, shows part of the collapsed roof of the Chernobyl nuclear power plant, destroyed by fire. (AP Photo/Efrm Lucasky) 
3. Aerial view of the Chernobyl nuclear power plant, after the largest nuclear disaster in human history. The photo was taken three days after the explosion at the nuclear power plant in 1986. In front of the chimney is the destroyed 4th reactor. (AP Photo) 
4. Photo from the February issue of the magazine “Soviet Life”: the main hall of the 1st power unit of the Chernobyl nuclear power plant on April 29, 1986 in Chernobyl (Ukraine). The Soviet Union acknowledged that there was an accident at the power plant, but did not provide additional information. (AP Photo) 
5. A Swedish farmer removes straw contaminated by radiation a few months after the Chernobyl explosion in June 1986. (STF/AFP/Getty Images) 
6. A Soviet medical worker examines an unknown child who was evacuated from the nuclear disaster zone to the Kopelovo state farm near Kiev on May 11, 1986. The photo was taken during a trip organized by Soviet authorities to show how they were coping with the accident. (AP Photo/Boris Yurchenko) 
7. Chairman of the Presidium of the Supreme Soviet of the USSR Mikhail Gorbachev (center) and his wife Raisa Gorbacheva during a conversation with the management of the nuclear power plant on February 23, 1989. This was the first visit of the Soviet leader to the station since the accident in April 1986. (AFP PHOTO/TASS) 
8. Kiev residents queue for forms before being tested for radiation contamination after the accident at the Chernobyl nuclear power plant, in Kyiv on May 9, 1986. (AP Photo/Boris Yurchenko) 
9. A boy reads a notice on the closed gate of a playground in Wiesbaden on May 5, 1986, which reads: “This playground is temporarily closed.” A week after the Chernobyl nuclear reactor explosion on April 26, 1986, the Wiesbaden municipal council closed all playgrounds after detecting radioactivity levels of 124 to 280 becquerels. (AP Photo/Frank Rumpenhorst) 
10. One of the engineers who worked at the Chernobyl Nuclear Power Plant undergoes a medical examination at the Lesnaya Polyana sanatorium on May 15, 1986, a few weeks after the explosion. (STF/AFP/Getty Images) 
11. Environmental activists mark railway cars containing radiation-contaminated dry whey. Photo taken in Bremen, northern Germany on February 6, 1987. The serum, which was delivered to Bremen for onward transport to Egypt, was produced after the Chernobyl nuclear power plant accident and was contaminated by radioactive fallout. (AP Photo/Peter Meyer) 
12. A slaughterhouse worker places fitness stamps on cow carcasses in Frankfurt am Main, West Germany, May 12, 1986. According to the decision of the Minister of Social Affairs of the federal state of Hesse, after the Chernobyl explosion, all meat began to be subject to radiation control. (AP Photo/Kurt Strumpf/stf) 
13. Archival photo from April 14, 1998. Workers at the Chernobyl nuclear power plant walk past the control panel of the destroyed 4th power unit of the station. On April 26, 2006, Ukraine celebrated the 20th anniversary of the Chernobyl accident, which affected the lives of millions of people, required astronomical costs from international funds and became an ominous symbol of the dangers of nuclear energy. (AFP PHOTO/GENIA SAVILOV) 
14. In the photo, which was taken on April 14, 1998, you can see the control panel of the 4th power unit of the Chernobyl nuclear power plant. (AFP PHOTO/GENIA SAVILOV) 
15. Workers who took part in the construction of the cement sarcophagus covering the Chernobyl reactor, in a memorable photo from 1986 next to the unfinished construction site. According to the Chernobyl Union of Ukraine, thousands of people who took part in the liquidation of the consequences of the Chernobyl disaster died from the consequences of radiation contamination, which they suffered during their work. (AP Photo/Volodymyr Repik) 
16. High-voltage towers near the Chernobyl nuclear power plant on June 20, 2000 in Chernobyl. (AP Photo/Efrem Lukatsky) 
17. A nuclear reactor operator on duty records control readings at the site of the only operating reactor No. 3, on Tuesday, June 20, 2000. Andrei Shauman angrily pointed at a switch hidden under a sealed metal cover on the control panel of the reactor at Chernobyl, a nuclear power plant whose name has become synonymous with nuclear disaster. “This is the same switch with which you can turn off the reactor. For $2,000, I’ll let anyone push that button when the time comes,” Schauman, acting chief engineer, said at the time. When that time came on December 15, 2000, environmental activists, governments and ordinary people around the world breathed a sigh of relief. However, for the 5,800 workers at Chernobyl, it was a day of mourning. (AP Photo/Efrem Lukatsky)
18. 17-year-old Oksana Gaibon (right) and 15-year-old Alla Kozimerka, victims of the 1986 Chernobyl disaster, are treated with infrared rays at the Tarara Children's Hospital in the capital of Cuba. Oksana and Alla, like hundreds of other Russian and Ukrainian teenagers who received a dose of radiation, were treated for free in Cuba as part of a humanitarian project. (ADALBERTO ROQUE/AFP)
19. Photo dated April 18, 2006. A child during treatment at the Center for Pediatric Oncology and Hematology, which was built in Minsk after the accident at the Chernobyl nuclear power plant. On the eve of the 20th anniversary of the Chernobyl disaster, representatives of the Red Cross reported that they were faced with a lack of funds to further assist the victims of the Chernobyl accident. (VIKTOR DRACHEV/AFP/Getty Images) 
20. View of the city of Pripyat and the fourth reactor of Chernobyl on December 15, 2000 on the day of the complete shutdown of the Chernobyl nuclear power plant. (Photo by Yuri Kozyrev/Newsmakers) 
21. A Ferris wheel and a carousel in a deserted amusement park in the ghost town of Pripyat next to the Chernobyl nuclear power plant on May 26, 2003. The population of Pripyat, which in 1986 was 45,000 people, was completely evacuated within the first three days after the explosion of the 4th reactor No. 4. The explosion at the Chernobyl nuclear power plant occurred at 1:23 a.m. on April 26, 1986. The resulting radioactive cloud damaged much of Europe. According to various estimates, from 15 to 30 thousand people subsequently died as a result of radiation exposure. Over 2.5 million residents of Ukraine suffer from diseases acquired as a result of radiation, and about 80 thousand of them receive benefits. (AFP PHOTO/ SERGEI SUPINSKY) 
22. In the photo from May 26, 2003: an abandoned amusement park in the city of Pripyat, which is located next to the Chernobyl nuclear power plant. (AFP PHOTO/ SERGEI SUPINSKY) 
23. In the photo from May 26, 2003: gas masks on the floor of a classroom in one of the schools in the ghost town of Pripyat, which is located near the Chernobyl nuclear power plant. (AFP PHOTO/ SERGEI SUPINSKY) 
24. In the photo from May 26, 2003: a TV case in a hotel room in the city of Pripyat, which is located near the Chernobyl nuclear power plant. (AFP PHOTO/ SERGEI SUPINSKY) 
25. View of the ghost town of Pripyat next to the Chernobyl nuclear power plant. (AFP PHOTO/ SERGEI SUPINSKY) 
26. Photo from January 25, 2006: an abandoned classroom in one of the schools in the deserted city of Pripyat near Chernobyl, Ukraine. Pripyat and the surrounding areas will remain unsafe for human habitation for several centuries. Scientists estimate that it will take about 900 years for the most dangerous radioactive elements to completely decompose. (Photo by Daniel Berehulak/Getty Images) 
27. Textbooks and notebooks on the floor of one of the schools in the ghost town of Pripyat on January 25, 2006. (Photo by Daniel Berehulak/Getty Images) 
28. Toys and a gas mask in the dust in a former elementary school in the abandoned city of Pripyat on January 25, 2006. (Daniel Berehulak/Getty Images) 
29. In the photo on January 25, 2006: an abandoned gym of one of the schools in the deserted city of Pripyat. (Photo by Daniel Berehulak/Getty Images) 
30. What remains of the school gym in the abandoned city of Pripyat. January 25, 2006. (Daniel Berehulak/Getty Images) 
31. A resident of the Belarusian village of Novoselki, located just outside the 30-kilometer exclusion zone around the Chernobyl nuclear power plant, in a photo taken on April 7, 2006. (AFP PHOTO / VIKTOR DRACHEV) 
32. A woman with piglets in the deserted Belarusian village of Tulgovichi, 370 km southeast of Minsk, April 7, 2006. This village is located within the 30-kilometer zone around the Chernobyl nuclear power plant. (AFP PHOTO / VIKTOR DRACHEV) 
33. On April 6, 2006, an employee of the Belarusian radiation-ecological reserve measures the level of radiation in the Belarusian village of Vorotets, which is located within the 30-kilometer zone around the Chernobyl nuclear power plant. (VIKTOR DRACHEV/AFP/Getty Images) 
34. Residents of the village of Ilintsy in the closed zone around the Chernobyl nuclear power plant, about 100 km from Kyiv, pass by rescuers from the Ministry of Emergency Situations of Ukraine who are rehearsing before a concert on April 5, 2006. Rescuers organized an amateur concert on the 20th anniversary of the Chernobyl disaster for more than three hundred people (mostly elderly people) who returned to live illegally in villages located in the exclusion zone around the Chernobyl nuclear power plant. (SERGEI SUPINSKY/AFP/Getty Images) 
35. The remaining residents of the abandoned Belarusian village of Tulgovichi, located in the 30-kilometer exclusion zone around the Chernobyl nuclear power plant, celebrate the Orthodox holiday of the Annunciation of the Virgin Mary on April 7, 2006. Before the accident, about 2,000 people lived in the village, but now only eight remain. (AFP PHOTO / VIKTOR DRACHEV) 
38. April 12, 2006, workers sweep away radioactive dust in front of the sarcophagus covering the damaged 4th reactor of the Chernobyl nuclear power plant. Due to high radiation levels, crews only work for a few minutes at a time. (GENIA SAVILOV/AFP/Getty Images) April 25, 1986. The Chernobyl nuclear power plant is scheduled to shut down the reactor to carry out scheduled preventive maintenance - this is a common practice for nuclear power plants. However, very often during such shutdowns, various experiments are carried out that cannot be carried out while the reactor is running.
At one o'clock in the morning on April 26, just one of these experiments was planned - testing the "turbogenerator rotor run-down" mode, which in principle could become one of the reactor protection systems during emergencies. We prepared for the experiment in advance. There were no surprises.
The city of power engineers Pripyat goes to bed. People discussed plans for the May holidays, talked about the upcoming match of the Cup Winners' Cup final between Dynamo (Kyiv) and Atlético (Madrid). The night shift was starting at the power plant.
During April 26, “Strana” will conduct an online report of events from the accident at the Chernobyl nuclear power plant thirty years ago, which led to a man-made and technological disaster of the millennium. As if it would happen tonight.
01:23 . An experiment begins at the 4th power unit of the Chernobyl nuclear power plant. But everything immediately went wrong.
The turbogenerator stopped faster than expected, the pump speed dropped, the water passed through the reactor more slowly and boiled faster. The avalanche-like growth of steam increased the pressure inside the reactor 70 times.
“Shut down the reactor!” the unit shift supervisor, Alexander Akimov, sharply shouted to operator Leonid Toptunov.
“But it was not in his power to do anything. All he could do was hold down the emergency protection button. He had no other means at his disposal,” Anatoly Dyatlov, deputy chief engineer of the station for operation, later wrote in his memoirs .
The multi-ton plate that covered the reactor from above simply flew off like a lid from a saucepan. As a result, the reactor was completely dehydrated, uncontrolled nuclear reactions began in it, and an explosion occurred. 140 tons of radioactive substances poison the air and people. From all over the city you can see a strange glow above the power unit. But few people see it - the city is sleeping peacefully.
01:27 . A fire breaks out in the premises of the power unit. Two NPP employees die under the rubble - MCP (Main Circulation Pump) pump operator Valery Khodemchuk (the body was not found, buried under the rubble of two 130-ton separator drums), and a commissioning plant employee Vladimir Shashenok (died from a broken spine and numerous burns at 6:00 at the Pripyat Medical Unit, on the morning of April 26th).
01:30 . An alarm sounded at the station. The first fire brigade is heading to the Chernobyl nuclear power plant. Within a few minutes, he begins to extinguish the power unit, without proper protection from radiation. The level of radiation is so high that after some time firefighters suddenly become victims of “radiation poisoning”: “nuclear tanning,” vomiting, the skin of their hands is removed along with their mittens.
H the fourth power unit after the disaster. A nuclear power reactor developed under the leadership of Anatoly Alexandrov, President of the USSR Academy of Sciences and Director of the Kurchatov Institute. In the 70s - 80s it was the most powerful reactor in the Soviet nuclear power industry.
01:32. The director of the Chernobyl Nuclear Power Plant, Viktor Bryukhanov, wakes up from a call from his colleagues, who see a glow over the station from the city. Bryukhanov jumps to the window and stands silently for some time, watching the terrible picture of the disaster. Then he rushes to call the station, but no one picks up for a long time. Eventually he calls the person on duty and calls an emergency meeting. He leaves for the station himself.
01:40. An ambulance arrives at the Chernobyl nuclear power plant. What happened is not really explained. Valentin Belokon, a 28-year-old doctor on duty at the Pripyat hospital, saw that there was nowhere to receive the injured: the door of the health center of administrative building No. 2, which served the 3rd and 4th power units, was closed. There weren’t even “petals” to protect the respiratory organs. We had to provide assistance to the victims right inside the ambulance. Fortunately, in the car there was a first aid package in case of a radiation accident. It contained disposable intravenous infusion medications. They immediately went into action.
01:51. 69 firefighters and all ambulances in the city of Pripyat were sent to the scene of the accident. Firefighters are also coming from surrounding towns. Part of the roof has been demolished, and a mixture of molten metal, sand, concrete and fuel particles is flowing down the walls of the nuclear power plant. They also spread throughout the sub-reactor rooms.
02:01. Despite the accident at the fourth unit, the remaining reactors of the nuclear power plant are producing energy as usual. Firefighters continue to work on the roof, some with severe signs of exposure. Some lose consciousness - more resilient comrades carry them on themselves. The fires on the roof of the turbine room and the reactor compartment of the station are gradually extinguished. The fire was prevented from spreading to neighboring power units. At the cost of incredible self-sacrifice of firefighters.
02.10. Mikhail Gorbachev is woken up and informed about the accident at Chernobyl. He later said that he was not immediately told about the scale of the disaster. Therefore, he limited himself to only instructing the USSR government to convene a meeting in the morning. And then he goes to bed.
02:15. Says Sergei Parashin, secretary of the party committee of the Chernobyl nuclear power plant: “At about 2.10-2.15 at night we were at the station. When we arrived, there was no longer a fire. But the very change in the configuration of the unit brought me to the appropriate state. We went into the office of the director of the nuclear power plant Bryukhanov. Bryukhanov was in depressed. I asked him: “What happened?” - “I don’t know.” He was usually taciturn, but that night... I think he was in a state of shock, inhibited. So no one reported that the reactor was blown up. Not a single deputy chief engineer gave it, and the chief engineer Bryukhanov himself went to the area of the fourth block - and he didn’t understand this either. People did not believe in the possibility of a reactor explosion; they developed their own versions and obeyed them."
02:21. The first victims have already begun to arrive at the medical station. However, doctors were unable to immediately determine the level of actual doses received by people due to the lack of information about the levels of radioactive radiation in the premises of the 4th block of the Chernobyl nuclear power plant, as well as in the surrounding areas. In addition, the victims were comprehensively irradiated, and many received extensive thermal burns. Shock states, nausea, vomiting, weakness, “nuclear tanning” and swelling speak for themselves.
03:30. The background radiation is measured at the site of the disaster. Before this, it was impossible to do this, since at the time of the accident the standard monitoring devices failed, and compact individual dosimeters simply went off scale. Only now are the employees of the nuclear power plant beginning to understand what really happened - the radiation is going through the roof.
05:00. The fire on the roof of the fourth power unit has been extinguished. However, the fuel continues to melt. The air is filled with radioactive particles. Gradually an understanding of the scale of the disaster comes.
06:00. Chernobyl nuclear power plant duty officer Vladimir Shashenok died from a huge radiation dose and severe burns. And Alexander Lelechenko, deputy head of the electrical department, felt so good after the IV drip that he asked to “breathe some street air” - and he quietly left the medical unit and reappeared at the emergency unit to provide all possible assistance at the Chernobyl nuclear power plant. The second time he was taken straight to Kyiv, where he died in terrible agony. In total, Lelechenko received a dose of 2,500 roentgens, so neither a bone marrow transplant nor intensive care could save him.
06:22. The air in the medical unit became so radioactive that the doctors themselves received radiation doses. After Hiroshima and Nagasaki, doctors in the Chernobyl nuclear power plant medical unit were the first to find themselves in such a difficult situation.
07:10. Doctors at the ambulance control room, located next to the emergency room in the Pripyat hospital building, have to receive dozens of patients at the same time. But the room is designed to accommodate up to 10 people - doctors have a limited supply of clean linen and only one shower facility. In the normal rhythm of city life, this is quite enough, but now the doctors are in a panic - no less than their patients.
07:15. A team consisting of Uskov A., Orlov V., Nekhaev A., shift supervisor of the 4th unit of the Chernobyl nuclear power plant Akimov A.F., senior reactor control engineer L.F. Toptunov. started work. Having manually opened the regulators and heard the sound of water, they returned back to the block panel. Upon returning to control room-4, Akimov A.F. and Toptunov L.F. It's getting bad. They are rushed to the hospital.
07:50. “Did you have graphite blocks lying around here before the accident?” “No, we just had a cleanup day for May 1.” This is a dialogue between the shift manager of the 4th unit of the Chernobyl nuclear power plant, Viktor Smagin, and the deputy head of reactor workshop No. 1 for operation, Vyacheslav Orlov.
08:00. Nikolai Karpan, deputy head of the nuclear physics laboratory, says: “We arrived at the station at eight o’clock in the morning. So I ended up in the bunker... The first thing I encountered in the bunker and what seemed very strange to me was that we didn’t know anything about what happened, No one said anything about the details of the accident. Yes, there was some kind of explosion. And we had no idea about the people and their actions that night, although work to localize the accident began from the very moment of the explosion. , that same morning I tried to restore the picture myself. I began to ask people, but then, in the bunker, we were told nothing about what was happening in the central hall, in the turbine hall, who of the people was there, how many people were evacuated to the medical unit, what kind of doses are there, at least supposedly... All those present in the bunker were divided into two parts. People were in a stupor - the director, the chief engineer were clearly in shock, and those who were trying to somehow influence the situation were actively protesting. influence it. Change it for the better."
08:10. There have still been no official messages from the authorities. Children go to school. But residents of Pripyat learn news about the accident from their neighbors and acquaintances; many are already sitting on their suitcases and waiting for official news - for example, about the announcement of an evacuation. But so far word of mouth is working.
09:00. Rumors about the accident reach Kyiv - from friends and relatives in Pripyat. They quickly spread throughout the capital of the Ukrainian SSR. There is no panic yet (no one understands the real scale of the tragedy). But it's alarming. They say that the party leadership and the KGB leadership are already evacuating their families from Kyiv. An official statement about the accident will be made only on April 28.
09:10. Alexander Esaulov, deputy chairman of the city executive committee of the city of Pripyat, says: “I’m sitting in the medical unit. As I remember now: the block is in full view. Nearby, right in front of us. Three kilometers from us. Smoke was coming from the block. Not that black... such a trickle smoke. Like from an extinguished fire, only from an extinguished fire it was blue, and this one was so dark. And then the graphite caught fire. It was late in the evening; Can you imagine? - we sat with the windows open all day.”
09:46. Deputy Chief Engineer of the Chernobyl Nuclear Power Plant Anatoly Dyatlov: “In the Pripyat hospital, a dosimetrist took measurements, threw off everything, washed, changed clothes and went to the ward. Completely exhausted, went straight to bed to sleep. No such luck. A nurse came with an IV. He begged: “Let me sleep.” , then do whatever you want." Persuasion is useless. And the strange thing is, after the drip that they poured in there - I don’t know, there is no sleep, cheerfulness appeared, and I left the room. Others have the same thing. There is lively talk in the smoking room, and everything about that , and about that. Reason, reason, reason?
10:00. By this time, many people already know about what happened in Pripyat. But few understand what really happened. Patrols with dosimeters and gauze bandages walk the streets. Some residents, without waiting for the evacuation announcement, pack their bags and leave to visit friends and relatives - some to Kyiv, and some outside Ukraine.
10:10. The first watering machines hit the streets of Pripyat. Stalls and kiosks began to close. And schoolchildren began to be given iodine tablets in the morning.
10:25. Even many residents of the town of nuclear workers did not imagine the scale of the tragedy. Many went out onto their balconies and watched through binoculars an incomprehensible glow at the station in broad daylight. Those who were in the know drove the curious back into the apartments with obscenities. “There’s an explosion, we’re all irradiated,” they shouted in the streets.
10:30. A south wind blows in Chernobyl, driving radioactive masses north. Away from Kyiv. Towards Belarus. And further to Scandinavia (where increased levels of radiation will soon be recorded). In the near future, Western “radio voices” will begin to talk about the accident with all their might. The Soviet media will continue to remain silent.
10:40. The first military helicopters flew to the reactor. They began dumping bags of sand and boric acid into the reactor. As Nikolai Volkozub, a colonel of the Ukrainian Air Force and a sniper pilot, later recalled, there was a continuous crackle in the headphones of the headset, and the needle on the on-board dosimeter went off scale. To measure the temperature, helicopters had to hover over the mouth of the reactor at the lowest possible altitude, which sometimes reached 20 meters.
10:45. The first operational interdepartmental group of nuclear specialists from Moscow, Leningrad, Chelyabinsk and Novosibirsk arrived in the capital of Ukraine.
11:00. Party bodies got in touch with the director of the Chernobyl nuclear power plant, Viktor Bryukhanov. In his report, he told the second secretary of the Kyiv regional committee of the CPSU about the explosion. At the same time, Viktor Bryukhanov assured the responsible employee that the radiation situation at the station was within normal limits and did not pose any threat.
Photo: MK/Viktor Bryukhanov, director of the Chernobyl nuclear power plant
11:15. A teachers' meeting was urgently held at the Pripyat city school. The city government announced that there was an accident at the nuclear power plant and it was temporarily isolated. However, there is no radiation leakage. At the same time, they advised not to let schoolchildren go outside.
11:30. Columns of military equipment began to enter the city - armored personnel carriers, infantry fighting vehicles and sapper clearing vehicles. At first, conscript soldiers did not even have the most primitive petal respirators. Television was suddenly turned off in Pripyat. And helicopters were constantly flying in the sky above the city.
11:45. An emergency meeting is ongoing in the Ministry of Medium Machine Building in Moscow. The Politburo of the CPSU Central Committee requested that scientists urgently assess the situation. However, there is still little information, and scientists find it difficult to assess the real situation. The only practical decision that was made was to fly to Kyiv at 16:00 to understand the situation on the spot. The delegation should be headed by Deputy Chairman of the Council of Ministers of the USSR Boris Shcherbina. He was urgently recalled from his business trip. It was decided not to make any statements until the conclusions of the Government Commission. The decision on evacuation, the possibility of which the Ukrainian party leadership asked Moscow about, has also not been made.
12:00. An order was received to dismiss the schoolchildren to their homes. When one of the teachers asked the children to cover their faces with homemade gauze bandages, people in civilian clothes, seeing the students on the streets in this form, ordered to remove the bandages.
12:15. Deputy Chief Engineer of the Chernobyl Nuclear Power Plant Anatoly Dyatlov recalls: “My wife came. She brought cigarettes, a razor, toiletries. She asked if I needed vodka? There had already been a rumor that vodka was very useful in case of a large dose of radiation. He refused. In vain. Not because it’s very Damn, dear, it’s useful, but because, it turned out, he refused for a long four and a half years. It’s, of course, a small loss, but if they drank it voluntarily on April 26, I don’t remember who they brought the first batch to on the evening of the 26th. Moscow. They announced the landing and the mourning women began to cry. I said: “Women, bury us early.” I realized the seriousness of our situation, frankly speaking, I thought that our optimism would not be justified for everyone.
12:30 . At an emergency meeting of the city committee of the CPSU, a decision was made not to report anything about the true scale of the tragedy, which had become known by that moment. However, it was decided to begin the evacuation of Pripyat residents on April 27. “Let them not take a lot of things with them - only the essentials. This is only for three days,” party workers instructed their subordinates.
12:45. Nobel laureate in literature Svetlana Alexievich, in her book “Chernobyl Prayer”, written on the basis of the memories of people who survived the disaster, provides the following testimony: “My friend Tanya Kibenok comes running. My father is with her, he’s in a car. We get in and go to the nearest village for milk, three kilometers out of town. We bought a lot of three-liter cans of milk - so that there was enough for everyone. But everyone was vomiting terribly from the milk... The victims kept losing consciousness, for some reason the doctors kept telling them that they were poisoned by gases. no one spoke about radiation. But the city was filled with military equipment, all the roads were blocked. Electric trains stopped running, no one spoke about radiation. Some soldiers were wearing respirators. There were open bags of cakes. on trays. Ordinary life. Only... They washed the streets with some kind of powder..."
13:00. Word of mouth worked and the first rumors about a terrible explosion at a nuclear power plant began to spread throughout Kyiv. People retell them to each other, but real panic is still far away. Radio and TV report nothing about the disaster.
13:15. As a social network user with the nickname mamasha_hru recalls, the morning of April 26 was remembered for the rest of her life: “Mom woke me up for school and it turned out that Dina, my older sister, had not left for the competition. Although she was supposed to be at six in the morning. To the question " why?" Mom replied that they weren’t allowed in. Who didn’t let them in? How didn’t they let them in? In general, Mom and Dina honestly trotted to the bus station at six, and there people in uniform told them to turn around and quickly go home. It was about six in the morning. Let me remind you that it started at half past two in the morning. There was no one to ask and consult with my mother: there was no phone, my father was away on a business trip, and it was too early to knock on the neighbors. As a result, in the morning my mother sent Dina and me to school. Unprecedented things were also happening at school. There was a wet rag in front of each door. There was a piece of soap near each washbasin, which had never happened before. Technicians were running around the school, wiping everything they could with rags. And, of course, there were rumors about an explosion. the stations looked completely unreal, and the teachers said nothing. So I wasn't particularly worried. And already at the beginning of the second lesson, two aunts came into the class and quickly handed out two small tablets to everyone.”
Photo: mk.ru/Measuring radiation levels in the Chernobyl zone
13:30. In the afternoon, people both in Kyiv and Pripyat began calling each other and warning that it was better not to go outside, and that windows and vents should be closed. “We didn’t even have a clue what a dosimeter was. And not everyone in the city of nuclear scientists understood what radiation was, what its threat was,” recalls former Pripyat resident Alexander Demidov.
13:45. A team of doctors from the 6th clinic in Moscow arrives in Pripyat. Under the leadership of Doctor Georgy Dmitrievich Selidovkin, the first batch of 28 injured liquidators was selected and urgently sent to Moscow. They acted quickly, there was no time for analysis, so the selection was carried out according to the degree of nuclear tanning. At three o'clock in the morning, on April 27, the plane with the victims on board took off from Boryspil to Moscow.
14:00. From the memoirs of a resident of Pripyat, Gelena Konstantinova, who was eight years old at the time of the disaster: “My classmate’s dad was on duty at the station right on the night shift, April 26. She told us in class what he talked about with her mother in the morning after the shift I remember that she said that my father talked about a strong explosion. And then during the lesson the teacher gave us iodine tablets. After class, my parents and I saw the station from afar, looking at it through binoculars. I asked my mother: “Why. is there smoke? Mom replied that there was an accident."
14:15. Anatoly Kolyadin, an employee of the Chernobyl Nuclear Power Plant, also became one of the first liquidators. I learned about the accident in the morning, at the bus stop, when I was on my way to my shift. “But no one spoke about the dead. We were dropped off at the checkpoint, and the bus left. Some warrant officer did not let us in. They began calling from the checkpoint to the station shift manager. We begin to understand that the radiation situation at the station is very bad: the reactor has collapsed, there is no tent, The separators are shining. Smoke is oozing from the shafts of the fourth reactor. We have nowhere to go. Finally, we started to make our way to the workplaces, and there were pieces of pipes and graphite lying around. This means that the active zone was opened. warned: “Lyuda, don’t let the children out of the house. Close the windows." The children still remember how they cried and asked their mother to let them go outside to play. The picture was terrible: children were playing in the sandbox, and armored personnel carriers were driving along the streets, soldiers were standing everywhere in chemical protection and with gas masks."
14:30. There were two realities in Pripyat and Chernobyl. Hell is at the station itself, and an avalanche of rumors in the cities of nuclear scientists. In every family at least someone worked at the Chernobyl nuclear power plant. People reassured each other and advised each other not to go outside and close the windows. News began to leak out to the people from a closed meeting of the city committee of the CPSU. But still no one realized the seriousness of what had happened. They said that the accident would be fixed in three days, or a week at most.
14:45. However, all hopes for a speedy resolution of the situation were in vain. But then they didn’t even know about it. In the meantime, the western wind was carrying a giant radioactive cloud to Belarus, Poland and the rest of Europe.
15:00. While in Pripyat people lived with rumors and hopes, and at the station itself the liquidators were struggling with the nuclear nightmare, Hungarian, Bulgarian and Romanian dry red wines began to be imported en masse into Kyiv stores.
15: 15. Meanwhile, in Moscow, at Vnukovo airport, members of the government commission gathered. Everyone is waiting for Deputy Head of the Council of Ministers Boris Shcherbina, who is about to arrive in Moscow from a business trip. Everyone is tense and taciturn. “Perhaps we have witnessed a huge catastrophe, something like the death of Pompeii,” academician Valery Legasov thinks out loud.
15:30. The first day of the Chernobyl disaster was coming to an end, and despite all the rumors and the first signs of a terrible tragedy, it was quite calm in Pripyat. The city practically lived a normal life.
16:00. If women in Pripyat repeated advice to each other to close the windows for the hundredth time, many of the men discussed the upcoming match of the USSR football championship between Dynamo Kyiv and Spartak Moscow, which was to take place on April 27 in Kyiv. The distance from the crash site to the capital’s stadium is only 130 kilometers. Looking ahead, let's say that Dynamo won that match with a score of 2-1. And 82,000 spectators gathered at the Republican Stadium in Kyiv.
16:15. Despite the fact that the courtyards and back rooms of Kyiv stores are filled with boxes of red wine, bottles are not displayed on the shelves. Store directors received a strange command to wait for a special order to start sales.
16:30. The director of the nuclear power plant, Viktor Bryukhanov, realizes the depth of the tragedy and begins to ask the chairman of the Pripyat city executive committee to begin evacuating the population. However, he is told that this issue is within the competence of the government commission from Moscow, which is already flying to Kyiv. Precious time is quickly running out.
Photo: pripat.city.ru/Fourth from the right is the chairman of the Pripyat city executive committee, Vladimir Voloshko.
16: 50. The head of the government commission, Boris Shcherbina, has finally arrived at Vnukovo airport. Members of the commission urgently board the liner, which heads for Kyiv. During the flight, Academician Valery Legasov explains to a high-ranking Soviet official how nuclear reactors at the Chernobyl nuclear power plant work.
Photo: Life.ru/Head of the Commission Boris Shcherbina
17:15. In military units of the Belarusian, Kyiv, Carpathian and Odessa military districts, under the guise of exercises, urgent background radiation measurements began. The data went to Moscow, to the State Security Committee.
17:45. The 12th Directorate of the USSR Ministry of Defense, which oversaw all issues related to nuclear weapons, had complete information about the tragedy. In the units that were subordinate to this control, security measures were immediately taken, even in those that were located very far from the Chernobyl nuclear power plant. For example, at a secret base located in the north of the GDR, at a distance of 1493 km from Kyiv. This is what reserve sergeant Yuri Palov, who served there in 1984-86, told Strana.
“Towards the evening of April 26, an order was received to limit time outside the barracks, and everyone was ordered to get chemical protection kits, and then the order came to put them on. The officers began to say something about endurance exercises. The Soviet channels were not accepted into the unit, we received newspapers from Union with a delay of two days. Therefore, they didn’t even guess. And then when our radio operators from the ZKP came from duty, they said that Western voices were broadcasting with all their might that a nuclear power plant had exploded in Chernobyl. That’s when I heard this word for the first time. !,” said Yuri Palov.
18:15. A government plane from Moscow landed safely at Kiev Boryspil airport. Right on the runway, the commission members were met by the entire leadership of Ukraine, led by the First Secretary of the Communist Party of Ukraine Vladimir Shcherbitsky. Everyone is extremely worried. After exchanging short, not entirely protocol greetings, both the commission members and the leadership of Ukraine got into the cars and the motorcade of black “Seagulls” and “Volgas” rushed towards Pripyat.
Photo:bulvar.com.ua/Vladimir Shcherbitsky
18:50. Station workers, firefighters and ordinary citizens continue to be admitted to the Pripyat city hospital. People complain of a burning sensation in the throat and eyes, nausea and vomiting. Doctors require telephone consultations with colleagues from Moscow Hospital No. 6. Moscow doctors advise giving patients a mixture of iodine and water.
19:30. The motorcade with the government commission made its first stop, about 90 kilometers from Pripyat. Everyone got out of the cars. Academician Valery Legasov, head of the union commission Boris Shcherbina, first secretary of the Communist Party Central Committee Vladimir Shcherbitsky and other members of the government commission first saw a glow over the station on the horizon. A bright scarlet glow occupied almost half of the sky.
20:00. The late afternoon sky over Pripyat was bright. The glow from the nuclear fire at the Chernobyl nuclear power plant was visible from everywhere. As the townspeople later recalled, it was in the evening that an inexplicable feeling of fear came over everyone. Residents hid in their apartments, while military patrols with dosimeters walked quietly through the unusually empty streets of the city. And military equipment drove up to the administrative building of the Chernobyl nuclear power plant.
20:20. The motorcade with members of the USSR government commission entered the city and stopped in complete silence on the central square of Pripyat.
20:30. The assembly hall of the local city executive committee was packed to capacity with leaders of all levels, from the instructor of the city committee of the CPSU to the senior engineering and technical staff of the station. Everyone expected that the government commission from Moscow would immediately make the right decisions and explain in detail what and how to do. The meeting began with a short report by NPP Director Viktor Bryukhanov.
21:00. The US National Security Agency received the first satellite images of the explosion at the Chernobyl nuclear power plant, and after their processing and the preliminary conclusion of experts, this data came to the desk of President Ronald Reagan. He immediately sends a request to Moscow via the hotline and receives no information. The Soviet leadership remains silent.
21:30. After the report of the director of the Chernobyl Nuclear Power Plant and after consulting with the members of the commission, its head Boris Shcherbina gives an urgent order to the military to urgently send units of chemical defense troops and helicopter units of the Kyiv Military District to Kiev.
22:40. The first helicopters from a military squadron based in northern Ukraine, near Chernigov, fly to Pripyat. Their crews make the first flights of the station itself and the fourth power unit itself, where the explosion occurred. Academician Valery Legasov boarded one of the machines and asked the crew to fly directly over the fourth block.
23:00. After landing, academician Valery Legasov reported to Boris Shcherbina that the worst thing had happened. The reactor exploded. He said that he saw the remains of nuclear fuel and graphite rods glowing bright red. The reactor cover was torn off by the explosion and lay almost vertically. The scientist was unable to assess the possible probability of a second explosion.
23:15. After a conversation with Legasov and the military, the head of the government commission, Boris Shcherbina, gives an urgent order to begin an urgent evacuation of the entire population of Pripyat on the morning of April 27. An urgent order was sent to bus depots and motor convoys in the Kyiv region to bring all transport to Pripyat. They decided to transport city residents to villages and small towns in the Kyiv, Bryansk and Gomel regions.
Photo: rusakkerman.livejournal.com
23: 50. In Moscow, the radiology department of Clinic No. 6 has run out of places. At least 200 people, the very first heavy liquidators, were brought here. All free space is filled with beds with firefighters and Chernobyl NPP employees brought from Pripyat. Dosimeters are off the charts. Patients are given painkillers. Doctors are literally falling off their feet from fatigue.
00:00. The first day of the Chernobyl disaster has ended. But the worst is yet to come. Thousands of victims, broken destinies, lies of party officials and the greatness of spirit of ordinary soldiers, firefighters, doctors and police officers.
On May 1, a festive demonstration will take place in Kyiv, and a few days after it, people will begin to storm trains and buses leaving Kyiv.
The truth about the tragedy, despite the total silence of the authorities and the press in the first days after the disaster, still broke out. And, as always happens, it began to give rise to monstrous rumors. Rumors circulated around Kyiv about new explosions due to which the city could fall underground.
Photo: AP/ May 9, 1986. Kiev residents queue for forms to be checked for radioactive contamination
The first official announcement of the disaster was made only on April 28 at 21:00 on the main USSR television program “Vremya”. The announcer read out the dry text: “An accident occurred at the Chernobyl nuclear power plant. One of the reactors was damaged. Measures are being taken to eliminate the consequences of the incident. The victims were provided with the necessary assistance. A government commission was created to investigate the incident.”
“Thanks to the effective measures taken, today we can say: the worst is behind us. The most serious consequences have been averted,” he said in a televised address. And Mikhail Gorbachev visited the station itself only in 1989.
Photo: TASS/Mikhail Gorbachev arrived at the Chernobyl nuclear power plant with his wife Raisa
At this time, real panic reigned in Europe. In Poland, farmers poured milk on the ground; in other countries, domestic and wild livestock began to be slaughtered en masse—indicators of radioactive contamination simply went off scale.
Photo: AP/ May 12, 1986. A slaughterhouse worker in Frankfurt am Main puts stamps on the suitability of meat. In Germany, after the Chernobyl explosion, all meat began to be subject to radiation control
Photo: AFP/June 1986. A Swedish farmer removes straw contaminated by radioactive fallout.
Two years will pass and academician Valery Legasov, who was the first scientist to look into the mouth of the reactor, will hang himself in his apartment. The official version is a depressed state due to increased responsibility. Before his death, he recorded a story on a voice recorder about little-known facts regarding the disaster (part of the message was deliberately erased by someone). Based on these audio recordings, the BBC made the film "Surviving the Disaster: The Chernobyl Nuclear Disaster."
Photo: tulapressa.ru/Academician Valery Legasov
On July 3, 1986, by decision of the Politburo of the CPSU Central Committee, the director of the Chernobyl Nuclear Power Plant, Viktor Bryukhanov, was expelled from the party “for major errors and shortcomings in work that led to an accident with serious consequences.” And on July 29, 1987, the judicial panel for criminal cases of the Supreme Court of the USSR sentenced him to 10 years in prison to serve the sentence in a general correctional labor institution.
Photo: Izvestia/Viktor Bryukhanov, first on the left, in the dock
According to the World Health Organization, the accurately established number of victims of Chernobyl who died from cancer after exposure to severe radiation reaches 4,000 people. Another 5,000 people were in the group that received a smaller, but quite harmful dose of radiation. WHO experts note that there is no clear evidence of increased mortality and morbidity among the 5 million people who still live in contaminated areas of Ukraine, Belarus and Russia.
However, there is another point of view; some Western scientists believe that the number of deaths due to radiation after the Chernobyl nuclear power plant disaster could reach a million people.
Second explosion at the Chernobyl nuclear power plant April 26th, 2017
On the night of April 25-26, 1986, the largest nuclear man-made disaster in the world occurred - the accident at the Chernobyl nuclear power plant
The Chernobyl accident is one of the most horrific examples of the dangers nuclear power can pose if it is not kept under constant control. However, the accident itself could have turned into something much more terrible if not for the actions of three people.
Probably everyone has heard that after the accident at the Chernobyl nuclear power plant, heavy radioactive water was pumped out from under the reactor by firefighters, and this heroic act became known to the widest sections of the public.
But few people know that before the water was pumped out, it had to be drained from the durable concrete box in which it was located. And how to do it? After all, the outlet hatches were under a thick layer of radioactive water.
A second explosion could not be avoided!
Few people know about the threat of a second explosion of a nuclear reactor; this information was not circulated for a long time; the possible consequences were too terrifying. A new round of tragedy unfolded on the fifth day after the first explosion, then it became clear: if decisive action is not taken, the disaster will claim even more lives and lead to the contamination of large areas in Russia, Ukraine and Europe.
After the accident, when the fire was knocked down, the reactor became heated. It seemed to be in a suspended state, having under it a so-called bubble pool, which, as a result of the destruction of the pipelines of the cooling system, was filled with water. To limit exposure to radiation from above, as is already known, the reactor was sealed with a giant plug of sand, lead, dolomite, boron and other materials. And this is an additional burden. Will the hot reactor survive it? If not, then the whole colossus will collapse into the water. And then? - No one in the world has ever given an answer to such a question, what could happen. But here it had to be given immediately.
The temperature of the explosion was so high that the reactor (containing 185 tons of nuclear fuel) continued to melt at an incredible rate, getting closer and closer to the water tank that was used as coolant. It was obvious: if a hot reactor came into contact with water, a powerful steam explosion would form.
It was urgently necessary to find out about the amount of water in the pool, determine its radioactivity, and decide how to remove it from under the reactor. These issues were resolved as soon as possible. Hundreds of fire engines participated in this operation, diverting water to a special safe place. But there was no calm - the water remained in the pool. There was only one way to release her from there - to open two valves that were under a layer of radioactive water. If we add to this that in the barbatter pool, which looked like a huge bathtub after the accident, there was pitch darkness, if the approaches leading to it are narrow and also dark, and there was a high level of radiation around, then it will become clear what people had to do who had to do this work.
They volunteered themselves - the shift manager of the Chernobyl station B. Baranov, the senior control engineer of the unit of turbine shop number two V. Bespalov and the senior mechanical engineer of reactor shop number two A. Ananenko. The roles were distributed as follows: Alexey Ananenko knows the locations of the valves and will take on one, and show the second to Valery Bespalov. Boris Baranov will help them with light.
The operation has begun. All three were dressed in wetsuits. We had to work in respirators.
Here is the story of Alexey Ananenko:
We thought about everything in advance so as not to hesitate on the spot and get it done in the minimum amount of time. We took dosimeters and flashlights. We were informed about the radiation situation both above and in the water. We walked along the corridor to the barbutter pool. Pitch darkness. They walked in the rays of lanterns. There was also water in the corridor. Where space allowed, we moved in dashes. Sometimes the light disappeared, they acted by touch. And here's a miracle - the shutter is under your hands. I tried to turn it - it gave in. My heart skipped a beat with joy. But you can’t say anything - in a respirator. I showed Valery another one. And his valve gave way. A few minutes later a characteristic noise or splashing was heard - the water began to flow.
There are other memories on this topic:
"...Academicians E.P. Velikhov and V.A. Legasov *CONVINCED* the Government Commission of the possibility of another cataclysm - a steam explosion of catastrophic power, from burning the reactor support plate with molten fuel and getting this melt into the water-filled B-B (sub-reactor premises of two-story bubbler pools). According to academicians, calculations show that this explosion can destroy the Chernobyl Nuclear Power Plant completely and cover the whole of Europe with radioactive materials. The explosion can be prevented in only one way - you need to drain the water from the sub-reactor bubbler pools (if there is any there, and did not evaporate during the fire after fuel poisoning, which took place on the evening of April 26 - at night of April 27).
In order to check the presence of water in the B-B, Chernobyl NPP workers opened the valve on the impulse line tube coming out of the B-B. They opened it - there was no water in the tube, on the contrary - the tube began to draw air towards the pools. Scientists were not convinced by this fact; they continued to demand more significant evidence of the absence of water in B-B. The government commission set the leadership of the Chernobyl Nuclear Power Plant the task of finding and pointing out to the military a place in the wall B-B (which is 180 cm of very strong reinforced concrete) in which a hole could be made using an explosion to drain the water. There was no information about how dangerous this explosion could be for the building of the destroyed reactor. On the night of May 4th, this order reached the Deputy Chief Engineer of the Chernobyl Nuclear Power Plant, Alexander Smyshlyaev, who immediately forwarded it to the shift supervisor of Unit No. 3, Igor Kazachkov. Kazachkov replied that breaking through an almost two-meter wall in conditions of increased radiation is not the best way to dehydrate pools, and that he will look for a more gentle option. After looking at the technological diagrams, I. Kazachkov decided to investigate the possibility of opening two valves on the emptying lines B-B. He took a flashlight and a DP-5 dosing device and, together with operator M. Kastrygin, went to the valve room. The room was flooded by about 1.5 meters with radioactive water with an EDR above 200 r/hour (the instrument needle went off scale), but the valves themselves were intact, because the explosion did not reach these rooms and did not destroy anything. Having returned, the shift supervisor reported to Smyshlyaev that without pumping water from the pipeline corridor, it would not be possible to open the drain valves. But in any case, it will be easier to pump out the “dirty” water than to blow up the B-B wall.
And the radioactivity in the half-flooded basement floors of the station will sharply decrease. The proposal of Igor Ivanovich Kazachkov was accepted. On the morning of May 5, the Government Commission sent to the Chernobyl Nuclear Power Plant a team of military and firefighters, which had long been preparing to pump out the basement, led by Pyotr Pavlovich Zborovsky, captain of the civil defense troops. From the Chernobyl Nuclear Power Plant, at the initial stage of preparing the operation in early May, he was helped by V.K. Bronnikov, at that time acting chief engineer...
When its level near the drain valves B-B under block No. 4 dropped to about 50 cm, senior engineers A. Ananenko and V. Bespalov went to them, by order of the head of the reactor workshop V. Grishchenko. They were accompanied by B. Baranov, the station shift supervisor. Dressed in wetsuits, with flashlights and wrenches in their hands, they reached the valves and checked the numbers using the markings. Boris Baranov stood on the belay, and Alexey Ananenko and Valery Bespalov manually began to open the drain lines. This took about 15 minutes. The sound of water draining from the lower floor of the pool convinced them that the desired result had been achieved. Returning after completing the task, they checked their dosimeters (they were given DKP-50 optical dosimeters, military-style “pencils”), they each had 10 annual standards.
."
Upon returning, Alexey Ananenko gave an interview to Soviet media. There was not the slightest sign that this man had received a lethal dose of radiation poisoning. But none of the brave men managed to escape their fate.
Many sources indicate that Alexey and Valery died ten days later in one of the Moscow hospitals. Boris lived a little longer. All three were buried in tightly sealed zinc coffins. However
Several months later it was determined that molten lava could indeed set the reactor on fire. Soviet scientists suggested that the possible area of contamination could reach 200 square meters. km, modern experts are inclined to argue that it would take about 500 thousand years to eliminate the consequences of radioactive contamination from a potential explosion.
So these three almost certainly saved the lives of hundreds of thousands of people across Europe.
But almost no one knows about their sacrifice...
Valery Bespalov was still working at the Chernobyl plant in 2008: http://www.webcitation.org/6dhjGCHFo
Alexey Ananeko is currently the director for institutional development of the Ukrainian Nuclear Forum association: http://www.webcitation.org/6dhhLLaZu
Here, by the way, is a fairly recent interview with Alexey Ananenko about those events: http://www.souzchernobyl.org/?id=2440
To keep up to date with upcoming posts on this blog there is a Telegram channel. Subscribe, there will be interesting information that is not published on the blog!
I can tell you more about it, and here’s how it went
Based on the analysis of old and new data, a realistic version of the causes of the Chernobyl accident has been developed. Unlike earlier official versions, the new version provides a natural explanation for the accident process itself and many circumstances preceding the moment of the accident, which have not yet found a natural explanation.
1. Causes of the Chernobyl accident. The final choice between the two versions
1.1. Two points of view
There are many different explanations for the causes of the Chernobyl accident. There are already over 110 of them. And there are only two scientifically reasonable ones. The first of them appeared in August 1986 /1/ Its essence boils down to the fact that on the night of April 26, 1986, the personnel of the 4th unit of the Chernobyl nuclear power plant, in the process of preparing and conducting purely electrical tests, grossly violated the Regulations 6 times, i.e. . rules for safe operation of the reactor. And for the sixth time, so rudely that it couldn’t be ruder - he removed from its core no less than 204 control rods out of 211 standard ones, i.e. more than 96%. While the Regulations required them: “When the operational reactivity margin decreases to 15 rods, the reactor must be immediately shut down” /2, p. 52/. And before that, they deliberately turned off almost all emergency protection. Then, as the Regulations required of them: “11.1.8. In all cases, it is prohibited to interfere with the operation of protections, automation and interlocks, except in cases of their malfunction...” /2, p. 81/. As a result of these actions, the reactor fell into an uncontrollable state, and at some point an uncontrollable chain reaction began in it, which ended in a thermal explosion of the reactor. In /1/ they also noted “carelessness in the management of the reactor installation”, insufficient understanding by “staff of the peculiarities of technological processes in a nuclear reactor” and loss of “sense of danger” by the staff.
In addition, some design features of the RBMK reactor were indicated, which “helped” the personnel to bring a major accident to the dimensions of a catastrophe. In particular, “The developers of the reactor facility did not provide for the creation of protective safety systems capable of preventing an accident in the event of a set of deliberate shutdowns of technical protective equipment and violations of operating regulations, since they considered such a combination of events impossible.” And one cannot but agree with the developers, because deliberately “disabling” and “violating” means digging one’s own grave. Who will do this? And in conclusion, it is concluded that “the root cause of the accident was an extremely unlikely combination of violations of the order and operating regime committed by the personnel of the power unit” /1/.
In 1991, the second state commission, formed by Gosatomnadzor and consisting mainly of operators, gave a different explanation of the causes of the Chernobyl accident /3/. Its essence boiled down to the fact that the reactor of the 4th block had some “design flaws” that “helped” the duty shift to bring the reactor to an explosion. The main ones are usually the positive steam reactivity coefficient and the presence of long (up to 1 m) graphite water displacers at the ends of the control rods. The latter absorb neutrons worse than water, so their simultaneous introduction into the core after pressing the AZ-5 button, displacing water from the control rod channels, introduced such additional positive reactivity that the remaining 6-8 control rods could no longer compensate for it. An uncontrollable chain reaction began in the reactor, which led to a thermal explosion.
In this case, the initial event of the accident is considered to be the pressing of the AZ-5 button, which caused the downward movement of the rods. The displacement of water from the lower sections of the control rod channels led to an increase in the neutron flux in the lower part of the core. Local thermal loads on fuel assemblies have reached values exceeding the limits of their mechanical strength. The rupture of several zirconium claddings of the fuel assemblies led to a partial separation of the reactor's upper protective plate from the casing. This resulted in a massive rupture of the technological channels and jamming of all the control rods, which by this moment had passed approximately half the way to the lower end switches.
Consequently, the scientists and designers who created and designed such a reactor and graphite displacers are to blame for the accident, and the personnel on duty have nothing to do with it.
In 1996, the third state commission, in which the operators also set the tone, analyzed the accumulated materials and confirmed the conclusions of the second commission.
1.2. Balance of opinions
Years passed. Both sides remained unconvinced. As a result, a strange situation arose when three official state commissions, each composed of authoritative people in their field, studied, in fact, the same emergency materials, but came to diametrically opposite conclusions. It was felt that there was something wrong there, either in the materials themselves, or in the work of the commissions. Moreover, in the materials of the commissions themselves, a number of important points were not proven, but simply declared. This is probably why neither side could indisputably prove that they were right.
The very relationship of blame between the staff and the designers remained unclear, in particular due to the fact that during the tests the staff “recorded only those parameters that were important from the point of view of analyzing the results of the tests” /4/. That's how they explained it later. This was a strange explanation, because even some of the main parameters of the reactor, which are always and continuously measured, were not recorded. For example, reactivity. “Therefore, the process of development of the accident was restored by calculation using a mathematical model of the power unit using not only printouts of the DREG program, but also instrument readings and the results of a personnel survey” /4/.
Such a long existence of contradictions between scientists and operators has raised the question of an objective study of all materials related to the Chernobyl accident accumulated over 16 years. From the very beginning, it seemed that this should be done on the principles adopted by the National Academy of Sciences of Ukraine - any statement must be proven, and any action must be naturally explained.
Upon careful analysis of the materials of the above commissions, it becomes obvious that their preparation was clearly influenced by the narrow departmental biases of the heads of these commissions, which, in general, is natural. Therefore, the author is convinced that in Ukraine only the National Academy of Sciences of Ukraine, which did not invent, design, build or operate the RBMK reactor, is truly capable of objectively and officially understanding the true causes of the Chernobyl accident. And therefore, neither in relation to the reactor of the 4th unit, nor in relation to its personnel, it simply does not and cannot have any narrow departmental biases. And her narrow departmental interest and direct official duty is the search for objective truth, regardless of whether individual officials from the Ukrainian nuclear energy like it or don’t like it.
The most important results of this analysis are outlined below.
1.3. About pressing the AZ-5 button or doubts develop into suspicions
It was noticed that when you quickly get acquainted with the voluminous materials of the Government Commission to Investigate the Causes of the Chernobyl Accident (hereinafter referred to as the Commission), you get the feeling that it was able to build a rather coherent and interconnected picture of the accident. But when you start reading them slowly and very carefully, in some places you get the feeling of some kind of understatement. As if the Commission underinvestigated something or left something unsaid. This especially applies to the episode of pressing the AZ-5 button.
“At 1 hour 22 minutes 30 seconds, the operator saw on the program printout that the operational reactivity margin was a value requiring immediate shutdown of the reactor. However, this did not stop the personnel, and the tests began.
At 1 hour 23 minutes 04 seconds. the SVR (stop and control valves - auto) TG (turbogenerator - auto) No. 8 were closed.....The existing emergency protection for closing the ISV... was blocked in order to be able to repeat the test if the first attempt was unsuccessful ....
After some time, a slow increase in power began.
At 1 hour 23 minutes 40 seconds, the unit shift supervisor gave the command to press the AZ-5 emergency protection button, upon a signal from which all emergency protection control rods were inserted into the core. The rods went down, but after a few seconds blows were heard...."/4/.
The AZ-5 button is an emergency shutdown button for the reactor. It is pressed in the most extreme case, when some emergency process begins to develop in the reactor, which cannot be stopped by other means. But from the quote it is clearly clear that there was no special reason to press the AZ-5 button, since not a single emergency process was noted.
The tests themselves were supposed to last 4 hours. As can be seen from the text, the staff intended to repeat their tests. And this would have taken another 4 hours. That is, the staff was going to conduct tests for 4 or 8 hours. But suddenly, already at the 36th second of the test, his plans changed, and he began to urgently shut down the reactor. Let us remember that 70 seconds ago, taking desperate risks, he did not do this, contrary to the requirements of the Regulations. Almost all authors noted this obvious lack of motivation for pressing the AZ-5 button /5,6,9/.
Moreover, “From a joint analysis of DREG printouts and teletypes, in particular, it follows that the emergency protection signal of the 5th category...AZ-5 appeared twice, and the first - at 01:23:39” /7/ . But there is information that the AZ-5 button was pressed three times /8/. The question is, why press it two or three times, if already the first time “the rods went down”? And if everything is going in order, then why are the staff showing such nervousness? And physicists began to suspect that at 01:23:40. or a little earlier, something very dangerous did happen, which the Commission and the “experimenters” themselves kept silent about, and which forced the staff to sharply change their plans to the exact opposite. Even at the cost of disrupting the electrical testing program with all the attendant troubles, administrative and material.
These suspicions intensified when scientists who studied the causes of the accident using primary documents (DREG printouts and oscillograms) discovered a lack of time synchronization in them. Suspicions intensified even more when it was discovered that for study they were given not the original documents, but their copies, “with no time stamps on them” /6/. This strongly resembled an attempt to mislead scientists regarding the true chronology of the emergency process. And scientists were forced to officially note that “the most complete information on the chronology of events is available only... before the start of the tests at 01:23:04 sec on April 26, 1986.” /6/. And then “the factual information has significant gaps... and there are significant contradictions in the chronology of the reconstructed events” /6/. Translated from scientific-diplomatic language, this meant an expression of distrust in the presented copies.
1.3. About the movement of control rods
And most of these contradictions can, perhaps, be found in the information about the movement of control rods into the reactor core after pressing the AZ-5 button. Let us recall that after pressing the AZ-5 button, all control rods had to be immersed in the reactor core. Of these, 203 rods are from the upper ends. Consequently, by the time of the explosion they should have plunged to the same depth, which was what the arrows of the synchronizers on the control room-4 should have reflected. But in reality the picture is completely different. For example, let's cite several works.
“The rods went down...” and nothing more /1/.
"01 h 23 min: strong impacts, control rods stopped before reaching the lower limit switches. The clutch power supply switch was turned off." This is recorded in the SIUR operational log /9/.
"...about 20 rods remained in the upper extreme position, and 14-15 rods sank into the core no more than 1....2 m..." /16/.
"...the displacers of the emergency rods of the safety control rods traveled a distance of 1.2 m and completely displaced the columns of water located under them...." /9/.
The neutron-absorbing rods went down and almost immediately stopped, going deeper into the core by 2-2.5 m instead of the required 7 m /6/.
“The study of the final positions of the control rods using selsyn sensors showed that about half of the rods stopped at a depth of 3.5 to 5.5 m” /12/. The question is, where did the other half stop, because after pressing the AZ-5 button, all (!) rods should go down?
The position of the arrows of the rod position indicators that remained after the accident suggests that... some of them reached the lower limit switches (a total of 17 rods, of which 12 were from the upper limit switches)" /7/.
From the above quotes it is clear that different official documents describe the process of moving the rods in different ways. And from the oral stories of the staff it follows that the rods reached about 3.5 m and then stopped. Thus, the main evidence of the movement of the rods into the core is the oral stories of the personnel and the position of the synchronizer switches in the control room-4. No other evidence could be found.
If the position of the arrows had been documented at the time of the accident, then on this basis it would be possible to confidently reconstruct the process of its occurrence. But, as it was found out later, this position was “recorded according to the readings of the selsyns on the day of April 26, 1986” /5/., i.e. 12-15 hours after the accident. And this is very important, because physicists who have worked with selsyns are well aware of their two “insidious” properties. First, if the selsyns-sensors are subjected to uncontrolled mechanical action, then the arrows of the selsyns-receivers can take any position. Secondly, if the power supply is removed from the selsyns, then the arrows of the receiver selsyns can also take any position over time. This is not a mechanical watch that, when broken, records, for example, the moment a plane crashes.
Therefore, determining the depth of insertion of the rods into the core at the time of the accident by the position of the arrows of the receiver synchronizers at Control Room-4 12-15 hours after the accident is a very unreliable method, because at the 4th block both factors influenced the synchronizers. And this is indicated by data from the work /7/, according to which 12 rods, after pressing the AZ-5 button and before the explosion, traveled a path 7 m long from the upper ends to the lower ones. It’s natural to ask how they managed to do this in 9 seconds, if the standard time for such a movement is 18-21 seconds/1/? There are clearly erroneous readings here. And how could 20 rods remain in the uppermost position if, after pressing the AZ-5 button, all (!) control rods are inserted into the reactor core? This is also clearly erroneous.
Thus, the position of the arrows of the selsyn receivers at the main control room-4, recorded after the accident, generally cannot be considered objective scientific evidence of the insertion of control rods into the reactor core after pressing the AZ-5 button. What then remains of the evidence? Only subjective testimony of highly interested persons. Therefore, it would be more correct to leave the question of inserting rods open for now.
1.5. Seismic shock
In 1995, a new hypothesis appeared in the media, according to which. The Chernobyl accident was caused by a narrowly directed earthquake with a magnitude of 3-4, which occurred in the Chernobyl nuclear power plant area 16-22 seconds before the accident, which was confirmed by the corresponding peak on the seismogram /10/. However, nuclear scientists immediately rejected this hypothesis as unscientific. In addition, they knew from seismologists that an earthquake of magnitude 3-4 with an epicenter in the north of the Kyiv region was nonsense.
But in 1997, a serious scientific work /21/ was published, in which, based on the analysis of seismograms obtained at three seismic stations at once, located at a distance of 100-180 km from the Chernobyl nuclear power plant, the most accurate data about this incident were obtained. It followed from them that at 1 hour 23 minutes. 39 sec (±1 sec) local time, a “weak seismic event” occurred 10 km east of the Chernobyl nuclear power plant. The MPVA magnitude of the source, determined from surface waves, was in good agreement at all three stations and amounted to 2.5. The TNT equivalent of its intensity was 10 tons. It turned out to be impossible to estimate the depth of the source from the available data. In addition, due to the low level of amplitudes on the seismogram and the one-sided location of seismic stations relative to the epicenter of this event, the error in determining its geographical coordinates could not be higher than ±10 km. Therefore, this “weak seismic event” could well have occurred at the location of the Chernobyl nuclear power plant /21/.
These results forced scientists to pay more attention to the geotectonic hypothesis, since the seismic stations where they were obtained turned out to be not ordinary, but hypersensitive, because they monitored underground nuclear explosions all over the world. And the fact that the earth shook 10 - 16 seconds before the official moment of the accident became an indisputable argument that could no longer be ignored.
But it immediately seemed strange that these seismograms did not contain peaks from the explosion of the 4th block at its official moment. Objectively, it turned out that seismic vibrations, which no one in the world noticed, were registered by the station instruments. But for some reason the explosion of the 4th block, which shook the earth so much that it was felt by many, the same devices, capable of detecting an explosion of only 100 tons of TNT at a distance of 12,000 km, were not registered. But they should have registered an explosion with an equivalent power of 10 tons of TNT at a distance of 100-180 km. And this also did not fit into logic.
1.6. A new version
All these contradictions and many others, as well as the lack of clarity in the materials on the accident on a number of issues, only strengthened scientists’ suspicions that the operators were hiding something from them. And over time, a seditious thought began to creep into my head, but didn’t the opposite actually happen? First there was a double explosion of the reactor. A light purple flame 500 m high shot up above the block. The entire building of the 4th block shook. Concrete beams began to shake. “A blast wave saturated with steam burst into the control room (control room-4”). The general light went out. Only three lamps, powered by batteries, remained lit. The personnel at Control Room-4 could not help but notice this. And only after that, having recovered from the first shock, he rushed to press his “stop tap” - the AZ-5 button. But it was already too late. The reactor went into oblivion. All this could have taken 10-20-30 seconds after the explosion. Then, it turns out that the emergency process did not begin at 1 hour 23 minutes. 40 seconds from pressing the AZ-5 button, and a little earlier. This means that the uncontrolled chain reaction in the reactor of the 4th block began before the AZ-5 button was pressed.
In this case, the peaks of seismic activity that clearly contradict the logic, recorded by ultra-sensitive seismic stations in the Chernobyl nuclear power plant area at 01:23:39, receive a natural explanation. This was a seismic response to the explosion of the 4th block of the Chernobyl nuclear power plant.
They also get a natural explanation for the emergency repeated pressing of the AZ-5 button and the nervousness of the personnel in conditions when they were going to calmly work with the reactor for at least another 4 hours. And the presence of a peak on the seismogram at 1 hour 23 minutes. 39 seconds and his absence at the official moment of the accident. In addition, such a hypothesis would naturally explain the hitherto unexplained events that happened just before the explosion, such as “vibrations”, “increasing hum”, “water hammer” from the main circulation pump /10/, “bouncing” of two thousand 80-kilogram pigs "assembly 11" in the Central Hall of the reactor and much more /11/.
1.7. Quantitative evidence
The ability of the new version to naturally explain a number of previously unexplained phenomena is, of course, direct arguments in its favor. But these arguments are rather qualitative in nature. And irreconcilable opponents can be convinced only by quantitative arguments. Therefore, we will use the “proof by contradiction” method. Let us assume that the reactor exploded “a few seconds later” after pressing the AZ-5 button and introducing graphite tips into the reactor core. Such a scheme obviously assumes that before these actions the reactor was in a controlled state, i.e. his reactivity was clearly close to 0ß. It is known that introducing all graphite tips at once can introduce additional positive reactivity from 0.2ß to 2ß depending on the state of the reactor /5/. Then, with such a sequence of events, the total reactivity at some point could exceed the value of 1ß, when an uncontrolled chain reaction with prompt neutrons begins in the reactor, i.e. explosive type.
If this is what happened, then designers and scientists should share responsibility for the accident along with the operators. If the reactor exploded before pressing the AZ-5 button or at the moment it was pressed, when the rods had not yet reached the core, then this means that its reactivity had already exceeded 1ß before these moments. Then, obviously, all the blame for the accident falls only on the personnel, who, simply put, lost control of the chain reaction after 01:22:30, when the Regulations required them to shut down the reactor. Therefore, the question of what value the reactivity was at the moment of the explosion acquired fundamental importance.
The readings of the standard ZRTA-01 reactimeter would definitely help answer this question. But they could not be found in the documents. Therefore, this issue was solved by different authors through mathematical modeling, during which possible values of total reactivity were obtained, ranging from 4ß to 10ß /12/. The balance of total reactivity in these works consisted mainly of the effect of positive reactivity run-down during the movement of all control rods into the reactor core from the upper end switches - up to +2ß, from the steam effect of reactivity - up to +4ß, and from the dehydration effect - up to +4ß. The effects from other processes (cavitation, etc.) were considered second-order effects.
In all these works, the accident development scheme began with the formation of an emergency protection signal of the 5th category (AZ-5). This was followed by the insertion of all control rods into the reactor core, which contributed to reactivity up to +2ß. This led to acceleration of the reactor in the lower part of the core, which led to the rupture of the fuel channels. Then the steam and void effects came into play, which, in turn, could bring the total reactivity to +10ß at the last moment of the reactor’s existence. Our own estimates of the total reactivity at the moment of explosion, carried out using the method of analogies based on American experimental data /13/, gave a close value - 6-7ß.
Now, if we take the most plausible value of reactivity 6ß and subtract from it the maximum possible 2ß introduced by the graphite tips, it turns out that the reactivity before the insertion of the rods was already 4ß. And such reactivity in itself is quite sufficient for almost instantaneous destruction of the reactor. The lifetime of the reactor at such reactivity values is 1-2 hundredths of a second. No personnel, even the most selective, are able to respond so quickly to the threat that has arisen.
Thus, quantitative estimates of reactivity before the accident show that an uncontrolled chain reaction began in the reactor of the 4th unit before pressing the AZ-5 button. Therefore, pressing it could not be the cause of a thermal explosion of the reactor. Moreover, under the circumstances described above, it no longer mattered at all when this button was pressed - a few seconds before the explosion, at the moment of the explosion or after the explosion.
1.8. What do the witnesses say?
During the investigation and trial, the witnesses who were at the control panel at the time of the accident were actually divided into two groups. Those who were legally responsible for the safety of the reactor said that the reactor exploded after pressing the AZ-5 button. Those who were not legally responsible for the safety of the reactor said that the reactor exploded either before or immediately after pressing the AZ-5 button. Naturally, in their memoirs and testimonies, both of them sought to justify themselves in every possible way. Therefore, this kind of material should be treated with some caution, which is what the author does, considering them only as auxiliary materials. Nevertheless, through this verbal stream of justifications, the validity of our conclusions is quite clearly demonstrated. We quote below some of the testimony.
“The chief operating engineer for the second stage of the nuclear power plant who conducted the experiment.....reported to me that, as is usually done, to shut down the reactor in the event of any emergency, he pressed the emergency protection button AZ-5” /14/.
This quote is from the memoirs of B.V. Rogozhkin, who worked as a station shift supervisor on the emergency night, clearly shows that at the 4th block, an “emergency situation” first arose, and only then the staff began to press the AZ-5 button. And an “emergency situation” during a thermal explosion of a reactor arises and passes very quickly - within seconds. If it has already arisen, then the staff simply does not have time to react.
"All events took place within 10-15 seconds. Some kind of vibration appeared. The hum grew rapidly. The power of the reactor first fell, and then began to increase, beyond regulation. Then - several sharp pops and two "water hammers". The second one is more powerful - with side of the central hall of the reactor, the lights went out on the control panel, the suspended ceiling slabs fell down, and all the equipment turned off" /15/.
This is how he describes the course of the accident itself. Naturally, without reference to the timeline. And here is another description of the accident given by N. Popov.
"... a hum of a completely unfamiliar character, a very low tone, similar to a human groan was heard (eyewitnesses of earthquakes or volcanic eruptions usually spoke about such effects). The floor and walls shook strongly, dust and small crumbs fell from the ceiling, the fluorescent lighting went out, then immediately there was a dull thud, accompanied by thunderous rumbles..." /17/.
“I. Kirshenbaum, S. Gazin, G. Lysyuk, who were present at the control panel, testified that they heard the command to shut down the reactor immediately before or immediately after the explosion” /16/.
“At this time I heard Akimov’s command to turn off the device. Literally immediately there was a strong roar from the direction of the turbine hall” (From the testimony of A. Kuhar) /16/.
From these readings it already follows that the explosion and the pressing of the AZ-5 button practically coincided in time.
This important circumstance is also indicated by objective data. Let us recall that the AZ-5 button was pressed for the first time at 01:23:39, and the second time two seconds later (teletype data). Analysis of seismograms showed that the explosion at the Chernobyl nuclear power plant occurred in the period from 01 hour 23 minutes 38 seconds - 01 hour 23 minutes 40 seconds /21/. If we now take into account that the shift in the time scale of teletypes in relation to the time scale of the all-Union reference time could be ±2 seconds /21/, then we can confidently come to the same conclusion - the explosion of the reactor and the pressing of the AZ-5 button practically coincided in time. And this directly means that the uncontrolled chain reaction in the reactor of the 4th block actually began before the first press of the AZ-5 button.
But what kind of explosion are we talking about in the testimony of witnesses, the first or the second? The answer to this question is contained in both the seismograms and the readings.
If the seismic station recorded only one of two weak explosions, then it is natural to assume that they registered a stronger one. And according to the testimony of all the witnesses, this was precisely the second explosion. Thus, we can confidently accept that it was the second explosion that occurred in the period from 01 hour 23 minutes 38 seconds - 01 hour 23 minutes 40 seconds.
This conclusion is confirmed by witnesses in the following episode:
“Reactor operator L. Toptunov shouted about an emergency increase in the reactor’s power. Akimov shouted loudly: “Shut down the reactor!” and rushed to the reactor control panel. Everyone had already heard this second command to shut down. This was apparently after the first explosion.... " /16/.
It follows that by the time the AZ-5 button was pressed for the second time, the first explosion had already occurred. And this is very important for further analysis. This is where it will be useful to carry out a simple time calculation. It is reliably known that the first press of the AZ-5 button was made at 01 hours 23 minutes 39 seconds, and the second at 01 hours 23 minutes 41 seconds /12/. The time difference between presses was 2 seconds. And in order to see the emergency readings of the device, realize them and shout “about an emergency increase in power”, you need to spend at least 4-5 seconds. It takes at least another 4-5 seconds to listen, then make a decision, give the command “Shut down the reactor!”, rush to the control panel and press the AZ-5 button. So, we already have a reserve of 8-10 seconds before the second press of the AZ-5 button. Let us remember that by this moment the first explosion had already occurred. That is, it took place even earlier and clearly before the first press of the AZ-5 button.
How much earlier? Taking into account the inertia of a person’s reaction to an unexpected danger, usually measured in several or more seconds, let’s add another 8-10 seconds to it. And we get the period of time that passed between the first and second explosions, equal to 16-20 s.
This estimate of 16 - 20 s is confirmed by the testimony of Chernobyl NPP employees O. A. Romantsev and A. M. Rudyk, who were fishing on the shore of the cooling pond on the emergency night. In their testimony they practically repeat each other. Therefore, we will present here the testimony of only one of them - O. A. Romantsev. Perhaps, it was he who described the picture of the explosion in the greatest detail, as it was seen from a great distance. This is precisely their great value.
“I saw very clearly a flame above block No. 4, which in shape was similar to a candle flame or a torch. It was very dark, dark purple, with all the colors of the rainbow. The flame was at the level of the cut of the pipe of block No. 4. It kind of went back and a second bang was heard, similar to the bursting of a geyser bubble. After 15 - 20 seconds, another torch appeared, which was narrower than the first one, but the flame also slowly grew 5-6 times, and then disappeared, like the first time. The sound was like a gunshot, loud and sharp.” /25/. It is interesting to note that both witnesses did not hear any sound after the first appearance of the flame. This means that the first explosion was very weak. A natural explanation for this will be given below.
True, the testimony of A. M. Rudyk indicates a slightly different time elapsed between the two explosions, namely 30 s. But this dispersion is easy to understand if we consider that both witnesses observed the scene of the explosion without a stopwatch in their hands. Therefore, their personal temporal sensations can be objectively characterized as follows: the time interval between the two explosions was quite noticeable and amounted to a time measured in tens of seconds. By the way, an employee of the IAE named after. I. V. Kurchatova V. P. Vasilevsky, referring to witnesses, also comes to the conclusion that the time elapsed between the two explosions is 20 s /25/. A more accurate estimate of the number of seconds that passed between two explosions was carried out in this work above - 16 -20 s.
Therefore, it is impossible to agree with the estimates of the value of this period of time at 1 - 3 seconds, as is done in /22/. Because these assessments were made based only on the testimony of witnesses who were in various rooms of the Chernobyl nuclear power plant at the time of the accident; they did not see the overall picture of the explosions and were guided in their testimony only by their sound sensations.
It is well known that an uncontrolled chain reaction ends in an explosion. This means that it started another 10-15 seconds earlier. Then it turns out that the moment of its beginning lies in the time interval from 01 hour 23 minutes 10 seconds to 01 hour 23 minutes 05 seconds. Surprisingly, it was precisely this moment in time that the main witness of the accident for some reason considered it necessary to highlight when he discussed the question of the correctness or incorrectness of pressing the AZ-5 button at exactly 01:23:40 (according to DREG): “I didn’t attach any importance then it doesn’t matter - the explosion would have occurred 36 seconds earlier" /16/. Those. at 01:23:04. As already discussed above, VNIIAES scientists pointed to this same point in time back in 1986 as the moment after which the chronology of the accident, reconstructed from the official copies of emergency documents presented to them, raised doubts in them. Are there too many coincidences? This doesn't happen just like that. Apparently, the first signs of an accident (“vibrations” and “a hum of a completely unfamiliar nature”) appeared approximately 36 seconds before the first press of the AZ-5 button.
This conclusion is confirmed by the testimony of the head of the pre-accident, evening shift of the 4th block, Yu. Tregub, who stayed for the night shift to help with the electrical experiment:
“The run-down experiment begins.
They disconnect the turbine from the steam and at this time look at how long the run-down will last.
And so the command was given...
We didn’t know how the coasting equipment worked, so in the first seconds I perceived... some kind of bad sound appeared... as if the Volga was starting to slow down at full speed and was skidding. Such a sound: doo-doo-doo... Turning into roar. The building began to vibrate...
The control room was shaking. But not like during an earthquake. If you count to ten seconds, a rumble was heard, the frequency of vibrations dropped. And their power grew. Then a blow sounded...
This blow was not very good. Compared to what happened next. A strong blow though. The control room shook. And when the SIUT shouted, I noticed that the main safety valve alarms were going off. Flashed in my mind: “Eight valves...open state!” I jumped back, and at that time the second blow came. This was a very strong blow. The plaster fell down, the whole building went down... the lights went out, then the emergency power was restored... Everyone was in shock...".
The great value of this testimony is due to the fact that the witness, on the one hand, worked as the head of the evening shift of the 4th block and, therefore, knew well its real condition and the difficulties of working on it, and, on the other hand, he already worked on the night shift simply a voluntary assistant and, therefore, was not legally responsible for anything. Therefore, he was able to remember and recreate the overall picture of the accident in the most detail of all the witnesses.
In these testimonies, the following words attract attention: “in the first seconds... some kind of bad sound appeared.” From this it clearly follows that the emergency situation at the 4th unit, which ended in a thermal explosion of the reactor, arose already “in the first seconds” after the start of electrical tests. And from the chronology of the accident it is known that they began at 01:23:04. If we now add a few “first seconds” to this moment, it turns out that the uncontrolled chain reaction on delayed neutrons in the reactor of the 4th block began at approximately 01:23:8-10 sec, which coincides quite well with our estimates of this moment given higher.
Thus, from a comparison of emergency documents and the witness statements cited above, we can conclude that the first explosion occurred approximately in the period from 01:23:20 to 01:23:30. It was he who caused the first emergency pressing of the AZ-5 button. Let us recall that not a single official commission, not a single author of numerous versions could give a natural explanation for this fact.
But why did the operational personnel of the 4th unit, who were not new to the business and, moreover, working under the guidance of an experienced deputy chief operating engineer, still lose control of the chain reaction? Memories provide an answer to this question.
“We did not intend to violate the ORM and did not violate it. Violation is when the indication is deliberately ignored, and on April 26 no one saw a stock of less than 15 rods......But, apparently, we overlooked...” /16/.
“Why Akimov was delayed with the team to shut down the reactor, now you won’t find out. In the first days after the accident, we still communicated until we were scattered into separate wards...” /16/.
These confessions were written by a direct, one might say, main participant in the emergency events many years after the accident, when he was no longer threatened with any trouble either from law enforcement agencies or from his former superiors, and he could write frankly. From them, it becomes obvious to any unbiased person that only the personnel are to blame for the explosion of the reactor of the 4th unit. Most likely, being carried away by the risky process of maintaining the power of a reactor that had fallen into self-poisoning mode through its own fault, at a level of 200 MW, the operating personnel first “overlooked” the unacceptably dangerous removal of control rods from the reactor core in an amount prohibited by the Regulations, and then “delayed” by pressing the AZ-5 button. This is the direct technical cause of the Chernobyl accident. And everything else is misinformation from the evil one.
And here it’s time to end all these far-fetched disputes about who is to blame for the Chernobyl accident, and blame everything on science, as exploiters love to do. Scientists were right back in 1986.
1.9. On the adequacy of DREG printouts
It can be argued that the author’s version of the causes of the Chernobyl accident contradicts its official chronology, based on DREG printouts and given, for example, in /12/. And the author agrees with this - indeed he contradicts it. But if you carefully analyze these printouts, it is easy to notice that this chronology itself after 01 hours 23 minutes 41 seconds is not confirmed by other emergency documents, contradicts the testimony of eyewitnesses and, most importantly, contradicts the physics of reactors. And VNIIAES specialists were the first to draw attention to these contradictions back in 1986, as already mentioned above /5, 6/.
For example, the official chronology, based on DREG printouts, describes the accident process in the following sequence /12/:
01 hour 23 minutes 39 seconds (via teletype) - AZ-5 signal registered. The AZ and RR rods began to move into the core.
01 hour 23 minutes 40 seconds (according to DREG) - the same.
01 hour 23 minutes 41 seconds (via teletype) - Emergency protection signal registered.
01 hour 23 minutes 43 seconds (according to DREG) - Signals for the acceleration period (AZS) and for excess power (AZM) appeared in all side ionization chambers (NIC).
01 hour 23 min 45 sec (according to DREG) - Reduction from 28,000 m3/h to 18,000 m3/h of the flow rates of the main circulation pumps not involved in the rundown, and unreliable readings of the flow rates of the main circulation pumps involved in the rundown...
01 hour 23 minutes 48 seconds (according to DREG) - Restoration of the flow rates of the main circulation pumps not involved in the rundown to 29000 m3/h. Further increase in pressure in the BS (left half - 75.2 kg/cm2, right - 88.2 kg/cm2) and BS level. Triggering of high-speed reducing devices for releasing steam into the turbine condenser.
01 hour 23 minutes 49 seconds - Emergency protection signal "increase in pressure in the reactor space."
While the testimony of, for example, Lysyuk G.V. talk about a different sequence of emergency events:
“...something distracted me. It was probably Toptunov’s cry: “The reactor’s power is growing at an emergency speed!” I’m not sure of the accuracy of this phrase, but that’s the meaning I remember. Akimov with a quick sharp movement jumped to the control panel and tore off the lid and pressed the "AZ-5" button..." /22/.
A similar sequence of emergency events, already cited above, is described by the main witness of the accident /16/.
When comparing these documents, the following contradiction attracts attention. From the official chronology it follows that the emergency increase in power began 3 seconds after the first press of the AZ-5 button. But witness testimony gives the opposite picture: first, an emergency increase in the power of the reactor began, and only then, after a few seconds, the AZ-5 button was pressed. The assessment of the number of these seconds, carried out above, showed that the period of time between these events could be from 10 to 20 seconds.
The DREG printouts directly contradict the physics of reactors. It was already mentioned above that the lifetime of a reactor with a reactivity above 4ß is hundredths of a second. And according to the printouts, it turns out that from the moment of the emergency increase in power, a full 6 (!) seconds passed before the technological channels began to burst.
However, the vast majority of authors for some reason completely neglect these circumstances and take the DREG printouts as a document that adequately reflects the accident process. However, as shown above, this is not actually the case. Moreover, this circumstance has long been well known to the Chernobyl NPP personnel, because the DREG program at the 4th unit of the Chernobyl NPP “was: implemented as a background task, interrupted by all other functions” /22/. Consequently, “...the time of an event in DREG is not the true time of its manifestation, but only the time of entering the signal about the event into the buffer (for subsequent recording on magnetic tape)” /22/. In other words, these events could have occurred, but at a different, earlier time.
This most important circumstance was hidden from scientists for 15 years. As a result, dozens of specialists wasted a lot of time and money on clarifying the physical processes that could lead to such a large-scale accident, relying on contradictory, inadequate DREG printouts and the testimony of witnesses who were legally responsible for the safety of the reactor and therefore had a strong personal interest in disseminating the version - " the reactor exploded after pressing the AZ-5 button." At the same time, for some reason, no attention was systematically paid to the testimony of another group of witnesses who were not legally responsible for the safety of the reactor and, therefore, more inclined to objectivity. And this most important, recently discovered circumstance further confirms the conclusions made in this work.
1.10. Conclusions of the “competent authorities”
Immediately after the Chernobyl accident, five commissions and groups were organized to investigate its circumstances and causes. The first group of specialists was part of the Government Commission, headed by B. Shcherbina. The second is a commission of scientists and specialists under the Government Commission, headed by A. Meshkov and G. Shasharin. The third is the investigative group of the prosecutor's office. The fourth is a group of specialists from the Ministry of Energy, headed by G. Shasharin. The fifth is the Chernobyl Nuclear Power Plant Operators Commission, which was soon liquidated by order of the Chairman of the Government Commission.
Each of them collected information independently of the other. Therefore, in their archives there was a certain fragmentation and incompleteness in emergency documents. Apparently, this determined the somewhat declarative nature of a number of important points in the description of the accident process in the documents they prepared. This is clearly visible from a careful reading, for example, of the official report of the Soviet government to the IAEA in August 1986. Later in 1991, 1995 and 2000. Various authorities established additional commissions to investigate the causes of the Chernobyl accident (see above). However, this shortcoming remained unchanged in the materials they prepared.
It is little known that immediately after the Chernobyl accident, a sixth investigative group formed by “competent authorities” worked to determine its causes. Without attracting much public attention to her work, she conducted her own independent investigation into the circumstances and causes of the Chernobyl accident, relying on her unique information capabilities. Following fresh leads, during the first five days, 48 people were interviewed and interrogated, and photocopies of many emergency documents were made. In those days, as is known, even bandits respected the “competent authorities”, and normal employees of the Chernobyl Nuclear Power Plant would not have lied to them. Therefore, the findings of the “organs” were of extreme interest to scientists.
However, these conclusions, classified as “top secret”, were made known to a very narrow circle of people. Only recently the SBU decided to declassify some of its Chernobyl materials stored in the archives. And although these materials are no longer officially classified, they still remain practically inaccessible to a wide range of researchers. Nevertheless, thanks to his persistence, the author managed to get to know them in detail.
It turned out that preliminary conclusions were made by May 4, 1986, and final ones by May 11 of the same year. For brevity, we present only two quotes from these unique documents that are directly related to the topic of this article.
“...the general cause of the accident was the low culture of nuclear power plant workers. We are not talking about qualifications, but about work culture, internal discipline and a sense of responsibility” (document No. 29 dated May 7, 1986) /24/.
“The explosion occurred as a result of a number of gross violations of operating rules, technology and non-compliance with the safety regime during the operation of the reactor of the 4th block of the nuclear power plant” (document No. 31 dated May 11, 1986) /24/.
This was the final conclusion of the “competent authorities”. They did not return to this issue again.
As you can see, their conclusion almost completely coincides with the conclusions of this article. But there is a "small" difference. The National Academy of Sciences of Ukraine came to them only 15 years after the accident, figuratively speaking, through a thick fog of misinformation from interested parties. And the “competent authorities” finally established the true causes of the Chernobyl accident in just two weeks.
2. Accident scenario
2.1. Origin Event
The new version made it possible to substantiate the most natural scenario of the accident. At the moment it seems like this. At 00 hours 28 minutes on April 26, 1986, switching to electrical testing mode, the personnel at Control Room-4 made a mistake when switching control from the local automatic control system (LAR) to the main range automatic power control system (AP). Because of this, the thermal power of the reactor dropped below 30 MW, and the neutron power dropped to zero and remained so for 5 minutes, judging by the readings of the neutron power recorder /5/. The process of self-poisoning with short-lived fission products automatically began in the reactor. This process itself did not pose any nuclear threat. On the contrary, as it develops, the ability of the reactor to maintain a chain reaction decreases until it stops completely, regardless of the will of the operators. All over the world, in such cases, the reactor is simply shut down, then they wait a day or two until the reactor restores its functionality. And then they launch it again. This procedure is considered ordinary, and did not present any difficulties for the experienced personnel of the 4th block.
But at nuclear power plant reactors this procedure is very troublesome and takes a lot of time. And in our case, it also disrupted the implementation of the electrical testing program with all the ensuing troubles. And then, trying to “finish the tests quickly,” as the staff later explained, they began to gradually remove the control rods from the reactor core. Such a conclusion was supposed to compensate for the decrease in reactor power due to self-poisoning processes. This procedure at nuclear power plant reactors is also common and poses a nuclear threat only if too many of them are removed for the given state of the reactor. When the number of remaining rods reached 15, the operating personnel had to shut down the reactor. This was his direct official responsibility. But he didn't.
By the way, the first time such a violation occurred was at 7:10 a.m. on April 25, 1986, i.e. almost a day before the accident, and lasted until about 14 hours (see Fig. 1). It is interesting to note that during this time the shifts of the operating personnel changed, the shift supervisors of the 4th block changed, the station shift supervisors and other station management changed and, strange as it may seem, none of them raised the alarm, as if everything was in order, although the reactor was already on the verge of explosion.. The conclusion involuntarily suggests itself that violations of this type, apparently, were a common occurrence not only in the 5th shift of the 4th block.
This conclusion is confirmed by the testimony of I.I. Kazachkov, who worked on April 25, 1986 as the head of the day shift of the 4th block: “I’ll say this: we repeatedly had less than the permissible number of rods - and nothing ...”, “... none of us imagined that this was fraught nuclear accident. We knew that it was impossible to do this, but we didn’t think..." /18/. Figuratively speaking, the reactor “resisted” such free treatment for a long time, but the staff still managed to “rape” it and cause it to explode.
The second time this happened was on April 26, 1986, shortly after midnight. But for some reason, the staff did not shut down the reactor, but continued to remove the rods. As a result, at 01:22:30. 6-8 control rods remained in the core. But this did not stop the staff, and they began electrical tests. At the same time, we can confidently assume that the personnel continued removing the rods until the very moment of the explosion. This is indicated by the phrase “a slow increase in power has begun” /1/ and the experimental curve of changes in reactor power as a function of time /12/ (see Fig. 2).
Nobody in the whole world works like this, because there are no technical means of safely controlling a reactor that is in the process of self-poisoning. The staff of the 4th block did not have them either. Of course, none of them wanted to blow up the reactor. Therefore, the withdrawal of rods beyond the permitted 15 could be carried out only on the basis of intuition. From a professional point of view, this was already an adventure in its purest form. Why did they go for it? This is a separate question.
At some point between 01:22:30 and 01:23:40, the personnel's intuition apparently changed, and an excessive number of rods were removed from the reactor core. The reactor switched to the mode of maintaining a chain reaction using prompt neutrons. Technical means for controlling reactors in this mode have not yet been created and it is unlikely that they will ever be created. Therefore, within hundredths of a second, the heat release in the reactor increased 1500-2000 times /5.6/, the nuclear fuel heated up to a temperature of 2500-3000 degrees /23/, and then a process began that is called a thermal explosion of the reactor. Its consequences made the Chernobyl Nuclear Power Plant “famous” throughout the world.
Therefore, it would be more correct to consider the excess withdrawal of rods from the reactor core as the event that initiated the uncontrolled chain reaction. As happened in other nuclear accidents that ended in a thermal explosion of the reactor, in 1961 and in 1985. And after the rupture of the channels, the total reactivity could increase due to steam and void effects. To assess the individual contribution of each of these processes, detailed modeling of the most complex and least developed, second phase of the accident is necessary.
The author's proposed scheme for the development of the Chernobyl accident seems more convincing and more natural than the insertion of all the rods into the reactor core after a belated pressing of the AZ-5 button. Because the quantitative effect of the latter among different authors has a rather large scatter from quite large 2ß to negligibly small 0.2ß. It is unknown which of them was realized during the accident and whether it was realized at all. In addition, “as a result of research by various teams of specialists... it became clear that the mere introduction of positive reactivity only by the control rods, taking into account all the feedback affecting the steam content, is not enough to reproduce such a power surge, the beginning of which was recorded by the centralized control system SCK SKALA IV Chernobyl nuclear power unit" /7/ (see Fig. 1).
At the same time, it has long been known that the removal of control rods from the reactor core itself can give a much larger reactivity run-out - more than 4ß /13/. This is, firstly. And, secondly, it has not yet been scientifically proven that the rods even entered the active zone. From the new version it follows that they could not enter there, because at the moment the AZ-5 button was pressed, neither the rods nor the active zone any longer existed.
Thus, the version of the exploiters, having withstood the test of qualitative arguments, did not stand up to the quantitative test and can be archived. And the scientists’ version, after a small amendment, received additional quantitative confirmation.
Rice. 1. Power (Np) and operational reactivity margin (Rop) of the reactor of the 4th block in the period of time from 04/25/1986 to the official moment of the accident on 04/26/1986 /12/. The oval marks the pre-emergency and emergency periods of time.
2.2. "First Explosion"
An uncontrolled chain reaction in the reactor of the 4th block began in some, not very large part of the core and caused local overheating of the cooling water. Most likely, it began in the southeastern quadrant of the core at a height of 1.5 to 2.5 m from the base of the reactor /23/. When the pressure of the steam-water mixture exceeded the strength limits of the zirconium pipes of the technological channels, they ruptured. The fairly overheated water almost instantly turned into fairly high-pressure steam. This steam, expanding, pushed the massive 2,500-ton reactor lid upward. For this, as it turned out, breaking just a few technological channels is quite enough. This ended the initial stage of the destruction of the reactor and the main one began.
Moving upward, the lid sequentially, like a domino, tore apart the rest of the technological channels. Many tons of superheated water almost instantly turned into steam, and the force of its pressure quite easily threw the “lid” to a height of 10-14 meters. A mixture of steam, fragments of graphite masonry, nuclear fuel, technological channels and other structural elements of the reactor core rushed into the resulting vent. The reactor cover spun in the air and fell back on its edge, crushing the upper part of the core and causing an additional release of radioactive substances into the atmosphere. The impact of this fall can explain the double nature of the “first explosion”.
Thus, from the point of view of physics, the “first explosion” was not actually an explosion as a physical phenomenon, but was a process of destruction of the reactor core by superheated steam. Therefore, Chernobyl NPP employees who were fishing on the shore of the cooling pond during the emergency night did not hear any sound after it. That is why seismic instruments at three ultra-sensitive seismic stations from a distance of 100 - 180 km were able to register only the second explosion.
Rice. 2. Change in power (Np) of the reactor of the 4th unit in the period of time from 23:00 on 04/25/1986 to the official moment of the accident on 04/26/1986 (enlarged section of the graph circled in an oval in Fig. 1). Notice the constant increase in reactor power right up to the explosion
2.3. "Second Explosion"
In parallel with these mechanical processes, various chemical reactions began in the reactor core. Of these, the exothermic zirconium-steam reaction is of particular interest. It begins at 900 °C and proceeds violently already at 1100 °C. Its possible role was studied in more detail in work /19/, in which it was shown that in the conditions of an accident in the core of the reactor of the 4th block, only due to this reaction, up to 5,000 cubic meters could be formed within 3 seconds. meters of hydrogen.
When the top “lid” flew into the air, this mass of hydrogen escaped into the central hall from the reactor shaft. Mixed with the air in the central hall, hydrogen formed a detonation air-hydrogen mixture, which then exploded, most likely from an accidental spark or hot graphite. The explosion itself, judging by the nature of the destruction of the central hall, was of a blasting and volumetric nature, similar to the explosion of the famous “vacuum bomb” /19/. It was he who smashed the roof, central hall and other rooms of the 4th block to smithereens.
After these explosions, the process of formation of lava-like fuel-containing materials began in the sub-reactor rooms. But this unique phenomenon is already a consequence of the accident and is not considered here.
3. Main conclusions
1. The root cause of the Chernobyl accident was the unprofessional actions of the personnel of the 5th shift of the 4th unit of the Chernobyl Nuclear Power Plant, who, most likely, being carried away by the risky process of maintaining the power of the reactor, which had fallen into self-poisoning mode due to the fault of the personnel, at the level of 200 MW, at first “overlooked” it unacceptable dangerous and prohibited by regulations removal of control rods from the reactor core, and then “delayed” pressing the emergency shutdown button of the AZ-5 reactor. As a result, an uncontrolled chain reaction began in the reactor, which ended in a thermal explosion.
2. The insertion of graphite displacers of control rods into the reactor core could not have been the cause of the Chernobyl accident, since at the moment the AZ-5 button was first pressed at 01:23 am. 39 sec. There were no longer any control rods or core.
3. The reason for the first press of the AZ-5 button was the “first explosion” of the reactor of the 4th block, which occurred approximately from 01 hours 23 minutes. 20 sec. until 01:23 min. 30 sec. and destroyed the reactor core.
4. The second press of the AZ-5 button occurred at 01:23 am. 41 sec. and practically coincided in time with the second, now real, explosion of the air-hydrogen mixture, which completely destroyed the building of the reactor compartment of the 4th block.
5. The official chronology of the Chernobyl accident, based on DREG printouts, does not adequately describe the accident process after 01:23. 41 sec. VNIIAES specialists were the first to draw attention to these contradictions. There is a need for its official revision, taking into account recently discovered new circumstances.
In conclusion, the author considers it his pleasant duty to express deep gratitude to Corresponding Member of NASU A. A. Klyuchnikov, Doctor of Physical and Mathematical Sciences A. A. Borovoy, Doctor of Physical and Mathematical Sciences E. V. Burlakov, Doctor of Technical Sciences E. M. Pazukhin and Candidate of Technical Sciences V.N. Shcherbin for a critical but friendly discussion of the results obtained and moral support.
The author also considers it his particularly pleasant duty to express deep gratitude to SBU General Yu. V. Petrov for the opportunity to familiarize himself in detail with part of the SBU archival materials related to the Chernobyl accident, and for oral comments on them. They finally convinced the author that the “competent authorities” are truly competent authorities.
Literature
The accident at the Chernobyl nuclear power plant and its consequences: Information from the State Committee of the USSR AE, prepared for a meeting at the IAEA (Vienna, August 25-29, 1986).
2. Standard technological regulations for the operation of NPP units with RBMK-1000 reactor. NIKIET. Report No. 33/262982 dated September 28, 1982
3. On the causes and circumstances of the accident at Unit 4 of the Chernobyl Nuclear Power Plant on April 26, 1986. Report of the USSR State Pedagogical Academy, Moscow, 1991.
4. Information about the accident at the Chernobyl nuclear power plant and its consequences, prepared for the IAEA. Atomic Energy, vol. 61, no. 5, November 1986.
5. IREP report. Arch. No. 1236 dated 02.27.97.
6. IREP report. Arch. No. 1235 dated 02.27.97.
7. Novoselsky O.Yu., Podlazov L.N., Cherkashov Yu.M Chernobyl accident. Initial data for analysis. RRC "KI", VANT, ser. Physics of Nuclear Reactors, vol. 1, 1994.
8. Medvedev T. Chernobyl notebook. New World, No. 6, 1989.
9. Report of the Government Commission “Causes and circumstances of the accident on April 26, 1986 at Unit 4 of the Chernobyl Nuclear Power Plant. Actions to manage the accident and mitigate its consequences” (Generalization of the conclusions and results of the work of international and domestic institutions and organizations) under the direction of. Smyshlyaeva A.E. Derzhkomatomnaglyad of Ukraine. Reg. No. 995B1.
11. Chronology of the development of the consequences of the accident at the 4th unit of the Chernobyl nuclear power plant and the actions of personnel to eliminate them. Report of the Institute of Nuclear Research of the Academy of Sciences of the Ukrainian SSR, 1990 and Eyewitness Testimonies. Appendix to the report.
12. See, for example, A. A. Abagyan, E.O. Adamov, E.V.Burlakov et. al. "Chernobyl accident causes: overview of studies over the decade", IAEA International conference "One decade after Chernobyl: nuclear safety aspects", Vienna, April 1-3, 1996, IAEA-J4-TC972, p.46-65.
13. McCullech, Millet, Teller. Safety of nuclear reactors//Materials of the International. conf. on the peaceful use of atomic energy, held on August 8-20, 1955. T.13. M.: Foreign publishing house. lit., 1958
15. O. Gusev. "At the borders of Chornobyl Bliskavits", vol. 4, Kiev, view. "Varta", 1998.
16. A.S. Dyatlov. Chernobyl. How it was. LLC Publishing House "Nauchtekhlitizdat", Moscow. 2000.
17. N. Popov. "Pages of the Chernobyl tragedy." Article in the newspaper "Bulletin of Chernobyl" No. 21 (1173), 05.26.01.
18. Yu. Shcherbak. "Chernobyl", Moscow, 1987.
19. E.M. Pazukhin. “The explosion of a hydrogen-air mixture as a possible cause of the destruction of the central hall of the 4th block of the Chernobyl nuclear power plant during the accident on April 26, 1986,” Radiochemistry, v. 39, no. 4, 1997.
20. "Analysis of the current security of the Shelter object and forecast assessments of the development of the situation." ISTC "Shelter" report, reg. No. 3836 dated December 25, 2001. Under the scientific guidance of Dr. Phys.-Math. Sciences A.A. Borovoy. Chernobyl, 2001.
21. V.N.Strakhov, V.I.Starostenko, O.M.Kharitonov et al. “Seismic phenomena in the area of the Chernobyl nuclear power plant.” Geophysical Journal, vol. 19, no. 3, 1997.
22. Karpan N.V. Chronology of the accident at the 4th block of the Chernobyl nuclear power plant. Analytical report, D. No. 17-2001, Kyiv, 2001.
23. V.A.Kashparov, Yu.A.Ivanov, V.P.Protsak et al. “Estimation of the maximum effective temperature and time of non-isothermal annealing of Chernobyl fuel particles during the accident.” Radiochemistry, v. 39, no. 1, 1997
24. "Z arkh_v_v VUCHK, GPU, NKVD, KGB", Special Issue No. 1, 2001. Vidavnitstvo "Sphere".
25. Analysis of the accident at the fourth block of the Chernobyl Nuclear Power Plant. Zv_t. Frequently 1. Deal with the emergency. Code 20/6n-2000. NVP "ROSA". Kyiv. 2001.