The accident at the Chernobyl nuclear power plant led to an ecological catastrophe. Scientists define the disaster by its scale as a planetary one. The uniqueness of the tragedy that took place is in the multidimensionality of negative social phenomena that it caused.
A large complex of environmental, medical, informational, social, scientific, legal, managerial, economic, production, technical, and everyday problems has arisen. All of them formed an ecological and social phenomenon, which has acquired the name in official, scientific and widespread use. This name is the consequences of the Chernobyl disaster.
Large-scale environmental violations around the ChNPP put in the first place the problem of the need to reorganize the life of thousands of people. This problem subordinated changes in social policy and management . New forms of activity were introduced, traditional production was reduced.
Residents of contaminated areas had to adapt not only to life under the influence of a radiological factor, but also to life in a changed society. This had to do with a number of new management approaches in the sphere of life in the region, with the changed legal norms, and most importantly, with the shortage of medical care in conditions of the risk of a number of diseases.
The need to adapt to personal changes in well-being and health has become a big problem for people. People believe that evacuating solved the task of saving the lives of the inhabitants of the region around the ChNPP. Consequently, the integral ethnic structure collapsed. It formed specific social groups of the victims: residents of the contaminated regions, liquidators, self-settlers, and migrants.
Each of them was specific in its own way. In particular, the settlers had to adapt to the consequences of radiation and stress. In addition, to a new place of residence, environment, and the like.
34 years after the disaster, some still managed to heal the wounds that arose from the accident – family, social, psychological. But there are those who are still looking for the true causes of the tragedy. They are in search of answers to questions. The price of these questions has not been presented to mankind yet – neither in monetary nor in moral terms. There is no meter on earth that can assess the life of the living and the death of the fallen.
Explosion causes – search for truth
It has been 34 years since the accident at the Chernobyl nuclear power plant. Since the end of 2000, the station has been completely shut down. In 2019, a new safe confinement covered the remains of the destroyed reactor and auxiliary facilities, concentrated at the end of 1986 under the Shelter object. Work is underway to finally transform the facility into an environmentally friendly system.
However, even now, there is no fully justified and internally contradictory scenario of the accident, with which all experts would agree. There are more than 100 versions of how the man-made disaster at the Chernobyl nuclear power plant actually occurred.
In early 1999, the Committee on Environmental Policy, Nature Management and Elimination of the Consequences of the Chernobyl Disaster of the Verkhovna Rada of Ukraine instructed a group of independent experts to analyze and study objective documents and facts, carry out the necessary research and prepare a report on this issue.
The authorities developed an analysis technique, created a data bank and completed the first part of the work. In a word, they have built a logical model of the accident circumstances. This makes it possible to begin to establish its real causes.
An analysis of the results of work on establishing the circumstances and causes of the accident suggests that after the accident, five commissions and groups were created with different key focus:
- a group of specialists as part of the Government Commission under the leadership of B. Shcherbina,
- the Commission of Scientists and Specialists under the Government Commission headed by V. Meshkov and G. Shasharin,
- a group of specialists from the USSR Ministry of Energy under the leadership of G. Shasharin,
- an investigative group of the prosecutor’s office (the head is not known),
- a commission of Chernobyl NPP specialists, which was eventually liquidated.
Representatives of the emergency facility who worked directly at the Chernobyl nuclear power plant at the time of the disaster did not actually take part in the investigation of the causes of the accident, which contradicted the existing practice in the former USSR. Groups and commissions collected information about the Chernobyl accident separately and independently.
Perhaps this decision was correct. It is not for us to judge, but it caused the fragmentation of important documents. There was no single center responsible for collecting data, registering, recording, storing, etc. Therefore, it is not surprising that the commissions made different, sometimes completely opposite conclusions about the accident. As a result, the first official version became insufficiently substantiated, and according to some questions, even wrong.
The NPP is an experimental bridgehead
Strengthening the pace of development of nuclear energy in the USSR was based on plans approved with the conviction of the real possibility of creating nuclear reactors with unlimited unit capacity. It was on these signs of a new type of reactor that the leadership of the former USSR was betting. A technical justification for the RBMK-1000 reactor was prepared in 1964. After that, the first power unit of the Leningrad NPP was successfully launched in 1973.
Subsequently, Academicians A. Aleksandrov and M. Dollezhal prepared designs for RBMK-1500, 2000, 2400, 3600 reactors. According to the above-mentioned scientists, “… Only the creation of reactors with a significant increase in power will ensure the future of reactor construction.” Then no one thought about the consequences of such a leap in the development of atomic physics.
The chain of RBMK creation was gaining momentum throughout the country. The designers reported on the next achievements, not paying attention to the criticisms of those people, forced to operate reactor facilities at the country’s strategic facilities.
It became clear from the results of the analysis. The massive construction of units with RBMK reactors began without creating a proper scientific and experimental base, without deep study and substantiation of all kinds of technical issues. In fact, the nuclear power plants operating in the former USSR, including the Chernobyl plant, have turned into testing grounds for numerous experiments.
The creators of RBMK are the Chief Designer of the reactor plant, academician N.A. Dollezhal, and a scientific leader of the project, academician A.P. Alexandrov.
When in 1988, in the Chernobyl zone, a verdict was passed in the case of the Chernobyl accident, neither Dollezhal nor Aleksandrov was in the dock. Dollezhal, as the chief designer of the reactor, first spoke publicly about the accident only ten years after the tragedy in Chernobyl.
He did not admit his guilt in it even indirectly and, having lived safely for 101 years, died in 2000 at his country house in Moscow, presented to him by Stalin for the successful test of the first Soviet atomic bomb. He laid the blame for the tragedy at the Chernobyl nuclear power plant on “the terribly unprofessional personnel of the ChNPP and the negligent operation of the equipment.”
Academician Aleksandrov believed almost until the end of his life that the reason for the accident at the Chernobyl nuclear power plant was a planned sabotage. According to his conclusion, the RBMK-1000 reactor was so safe that he was ready to install it “right under his bed.” Aleksandrov died in 1994 at the age of 91. On the eve of his death, he admitted that “… he repeatedly made attempts to persuade Dollezhal to eliminate the shortcomings in the design of the reactor.”
Outpacing the next Five-Year Plan
Today, it is no longer in doubt that the consequences of the failed experiment, which led to the tragedy at the Chernobyl nuclear power plant, we primarily associate with certain shortcomings of RBMK-type reactors, in particular, the lack of a solid body. Such a robust vessel is part of another type of reactors – VVER, installed abroad at most nuclear power plants.
At the time of the construction of the Chernobyl nuclear power plant, there was a serious lack of industrial capabilities for the manufacture of VVER-type reactors on a serial scale in the USSR. At the same time, the energy situation, the need to increase production rates and the foreign policy situation required urgent action. Therefore, when planning the construction of the Chernobyl power plant, the authorities gave the preference to the RBMK reactors.
Starting from the second half of the 70s of the last century, ahead of the next five-year plans, channel reactors took their places at several power plants on the territory of the Soviet Union, including the Chernobyl nuclear power plant. At that time, RBMKs were designed for 1000, and later even for 1500 and more MW of electricity.
VVER reactors had to generate only 440 MW. Only in the 80s, their power increased to 1000 MW. A feature closely related to the power of the reactor is their mass and dimensions. They had to maintain the internal pressure of the reactor. At the same time, they should be transportable, that is, satisfy the possibilities of their transportation by rail.
RBMK: how does it work?
The design of the RBMK-1000 reactor is a cylinder 14.5 m in diameter and 14.75 m in height. Its core is 11.8 m, and its height is 7 m. The core consists of 1,693 technological channels passing through a graphite structure of a special configuration. This assigned the role of an atomic reaction moderator.
Each of the channels has fuel elements, that is, fuel rods. They are of special alloys, which, among others, include enriched uranium in pellets. The number of fuel rods in each channel is 18. They are in the form of tubes, filled with uranium pellets, with a total weight of 204 tons.
Neutrons are heating, water passes along them, heating up to saturation temperature and forming a water-steam mixture. Special pumps pump water along the coolants. About 5200 m3 of water is pumping through the reactor in normal mode. 6 main circulation pumps do this stage.
The steam-water mixture passes through the reactor, then enters a special separator, which divides it into steam and water. The water returns to the pumps, and the reactor sucks it. Meanwhile, the high-pressure cylinder of the turbine supplies the steam. The steam pressure rotates the turbine there, connected to the flywheel of the generator. Thanks to this, electricity is generating. After the high-pressure cylinder, steam enters the low-pressure cylinders, where it condenses and, after heating, enters the reactor cycle again.
There are special emergency protection rods for emergency shutdown of the reactor. They are made of steel. Moreover, they absorb neutrons, thereby stopping the atomic reaction and reducing the temperature inside the reactor. They are completely removed from the reactor and are held in this position by electromagnets in normal operation.
Nuclear fuel in fuel rods has a design for a period of active operation for 1190 days. After that, the fuel elements are removed from the reactor. Then, they had to go through deactivation and removal of the final heat in the water basin. Afyer that, they are sent to special plants for regeneration – removal of ineffective fuel, or are buried in special repositories.
Why were non-targeted design agencies involved?
A negative practice of long-term construction of nuclear power plants developed in the nuclear power industry. It happened in the late 70s and early 80s of the last century. Due to the lack of the necessary functional capacities, organizations and departments with a non-target design profile began to design the nuclear power plants in pursuit of advanced results. In particular, specialists from the Hydroproject Institute worked on the project for the second stage of the ChNPP. In principle, they had no experience in developing projects for nuclear power plants.
The construction of the Chernobyl nuclear power plant began in 1970. The constructors began the first stage, two RBMK-1000 of the first generation, and put into operation only in 1978. The second stage, two RBMK-1000 of the second generation, began construction in 1974. The ingineers it put into operation only in 1983. The third stage, two RBMK-1000s, started building in 1977. The designers began the fourth stage, two RBMK-1500s, in 1985.
The simultaneous implementation of three technologies such as design, construction and operation of units with reactors of different generations and capacities, turned the Chernobyl nuclear power plant into a theoretically and practically uncontrollable facility, about which the management of the nuclear power plant has repeatedly warned the Ministry of Energy.
Significant miscalculations of the RBMK authors began to surface from the first years of RBMK-1000 operation. This was especially true of the operation of reactor facilities at the Chernobyl nuclear power plant. At all of its units, emergencies and unplanned reactor shutdowns caused attempts to bring the reactors closer to the design indicators of power generation. However, the authors of RBMK and officials from the USSR Ministry of Energy defiantly did not notice this dangerous trend.
The situation worsened in the spring of 1985. There were critical innovations at the Chernobyl nuclear power plant to the main technological document, the NPP Regulations. The changes led to an increase in the thermal power of the 1st and 2nd blocks up to 105% of the capacity, and of the 3rd and 4th blocks up to 102% of the capacity. The electricity generation plan for 1986 was approved taking into account these critical changes.
Scientists recognized the mistake in determining the maximum unit power of RBMK reactors at the highest level only after the accident. Such situations often happen in states with dictatorships of power.
They planned to shut down the 4th power of the Chernobyl nuclear power plant unit for repairs for April 1986. In accordance with the Rules of Technical Operation, scientists had to perform a large range of regular technical work with the identification of deficiencies in equipment during the shutdown of the unit. However, in addition to the planned activities, the authorities supposed to carry out three more tests. According to their functional characteristics, they can be completely experimental. There was not a single specialist with preliminary experience of working with such experiments at the Chernobyl NPP. First of all, this concerned:
- studies of energy release in the reactor core,
- an experiment with the run-out of a turbine generator,
- testing of a new emergency air cooling system for the reactor.
Thus, in April 1986, the Chernobyl NPP was preparing not only for the planned repair of the fourth power unit, but also for three critical experiments. They were completely different in content and complexity. Comparison of the events indicate the existence of significant disagreements that are of fundamental importance for the analysis. The official version of the accident is based on them. Moreover, documents confirm the factual chronology. This issue remains controversial to this day. Time will tell us whether we found points of contact.
Today, one thing remains objectively clear. The Chernobyl nuclear power plant has turned from a testing ground for dangerous experiments into a cemetery. First of all, it happened due to a whole complex of negative reasons, including technical flaws in the design of the reactor, proper professional training of personnel, the pursuit of achieving results. There are not only the remains of spent nuclear fuel. Also, in a sense, the souls of those who, at the cost of their own lives, did everything so that the entire planet would not turn into such a cemetery. How often today we ask ourselves the question – weren’t the deaths of heroes in vain, if more than three decades later we still haven’t learned a sense of responsibility for our planet?