What was Chernobyl for Ukraine? A national tragedy, a huge psychological trauma, a heavy burden for the economy. Chernobyl exploded not only due to personnel errors, neglect of safety rules and problems with the design of the reactor. The tragedy stemmed from a system that shielded nuclear power with a veil of secrecy. The Soviet system did not allow to publicize the information about previous accidents, even among specialists. This made a new major accident inevitable.
Today, Chernobyl-type reactors are no longer being built. However, there are still authoritarian regimes in the world that control the leakage of any information. After all, Ukraine still produces 50% of all electricity at nuclear power plants. We have something to share with the world regarding the Chernobyl experience. In addition, we have something to think about ourselves.
On Friday, April 25, residents of Pripyat were already waiting for the weekend. The previous weekend was by no means calm. The country’s leadership had made Saturday, April 19, an unpaid work day. It was a ritual for Lenin’s birthday. Work on the weekend on the eve of the birthday of the leader of the world proletariat was conditionally voluntary. But in fact, the party leadership obliged all citizens without exception to work on this day.
Mikhail Gorbachev did not participate in this event. He made an official visit to the German Democratic Republic. He promoted the ideas of his “acceleration” policy in the GDR. Also, the state leader’s compatriots did not disappoint. The Politburo reported that 159 million people, the majority of the population, went to work that day.
Pripyat before the accident
If you believe the Pripyat newspaper “Tribuna Energetika”, the citizens personally sought to take part in “Red Saturday”. Namely, the power structures called this day “red”. The article “Labor Day” stated that 22,000 residents of Pripyat went to work on “Red Saturday” free of charge. So, the workers of the ChNPP and other enterprises produced goods and services worth more than 100,000 rubles. The contribution of people involved in construction exceeded 220,000 rubles. The main efforts were directed to the 5th power unit of the ChNPP under construction. On the eve, builders and installers had already failed the second deadline for putting the facility into operation. Therefore, as the newspaper wrote, the technical staff of the construction department literally redoubled their efforts on Red Saturday.
The next weekend promised to be “the day off and nothin’”. Young couples in Pripyat were preparing for marriage registration on April 26. Komsomol, the Communist Youth Union, gladly helped with the organization of wedding celebrations. The Komsomol organization traditionally rented its premises for various “correct” celebrations. In parallel, the Komsomol issued ideological approval of the wedding ritual. The rite, based earlier on church traditions, was an ideology now.
So, the newlyweds laid flowers at the monuments to Lenin and memorials to the memory of the Heroes of the Great Patriotic War. There was the anti-alcohol campaign promoted by Gorbachev. So, the leadership of the party and the Komsomol advocated a “sober” rest in every possible way. There were few people who wanted to drink in Pripyat. This could not but please the local party unit. The authorities were satisfied. The wedding did not end with drunken fights between Chernobyl workers and builders from the villages.
In addition to the planned events, the townspeople rejoiced at the long-awaited improvement in the weather. The thermometer showed above 20C. For many residents, such weather guaranteed a picnic in nature, hiking, hunting, and fishing. Before this, “Tribune Energetic” posted a photo of a young resident of Pripyat with a huge catfish in his hands. The photo was accompanied by the caption: “Such a catch deserves a place in the “red corner”.
The newspaper “Tribuna Energetika” satisfied the interests of the townspeople in Pripyat. Besides, the Chernobyl edition “Znamya Pobedy” satisfied the readers of rural areas. The villagers were preparing for a busy weekend. They had to plant potatoes and seedlings of vegetables. Chernobyl, located 16 kilometers from Pripyat, was the administrative center of a traditionally rural region.
The long-awaited festive mood
Finally, the coming weekend had to be the beginning of a long holiday marathon. May 1 was the Day of International Workers’ Solidarity. It was an official holiday in the USSR. May 9, which marked the victory of the Soviet people in World War II, was the same official holiday. Ordinary people and workers of the party apparatus also celebrated it on a large scale. Thus, Friday, April 25, was the last opportunity to resolve all unfinished business. So, people assumed that the long-awaited festive mood will completely cover the city, in fact, postponing work until mid-May.
Like everyone else in Pripyat, the director of the Chernobyl NPP, Viktor Bryukhanov, was looking forward to a quiet weekend. He certainly needed a rest. After arriving from Moscow, Bryukhanov worked tirelessly, and returned home exclusively for sleep. Friday had no signs of trouble that could ruin the weekend. Minor problems in the workflow are commonplace, where can we go without them? In any case, there was no need to shut down any of the reactors to solve the problem.
The situation, which happened at the Zaporozhye NPP a few weeks ago, did not leave the head of the director of the Chernobyl NPP. On April 7, radioactivity kept there in the cooling water. The permissible norm was exceeded 14 times. Zaporozhye colleagues had to shut down the reactor for two weeks troubleshoot. It was also necessary to freeze the construction of the unfinished unit, and to stop the production of electricity. The third power unit was in need of repair. How did it end? The lack of electricity and the cancellation of the monthly bonus… But most importantly, there were a lot of questions from the party and government officials.
Innovations in the field of energy were initiated by the Minister himself
The Chernobyl nuclear power plant worked according to schedule. The ChNPP was one of the best in the industry. Officially, the station had an average of about five technological accidents or equipment failures per year. This was within the permissible limits and did not cause any particular complications in the work.
Before the long weekend, the station administration planned to shut down the 4th reactor. However, this was due solely to regular system checks: repairs in accordance with industry regulations.
Depending on the state of the reactor, such repair work could take several months. The Ministry of Energy and Electrification determined frequency and duration of stops. Its new leader was a determined person and planned energy innovations. He strove to achieve recognition of the party leadership. In this regard, the work of power engineers had often to make all kinds of experiments. The intervals between reactor shutdowns increased and the time for repair work reduced.
The increase in energy production, which had to be achieved in the course of the next experiment, should have pleased the top management. In 1985, the Chernobyl NPP exceeded the plan for generating electricity by 10%. Last but not least, thanks to the reduction in repair time. But in 1986, planned shutdowns significantly reduced electricity production compared to the previous year. The local party leadership did not like this course of events.
However, there were a number of industry standards that neither party officials nor the minister could ignore. In April, it was the turn of the 4th power unit to stop for repairs. Bryukhanov’s team was ready for this.
Traditionally, in such cases, shutdown of the reactor has been used to check its operation at a low power level. One of the challenges, planned to be carried out before the shutdown of the power unit, concerned a steam turbine. The design tried to make the reactor safer when the emergency protection is on.
The idea behind the Chernobyl experiment was pretty simple
There was almost a guarantee that the reactor will shutdown in the event of an emergency. And as a result, the power supply will be cut off. But the power unit still needs energy to pump the refrigerant into the superheated reactor. This prevents it from melting.
Emergency diesel generators had e to solve this problem. They had to ensure the supply of electricity needed to pump water. However, they turned on only 45 seconds after the shut down of the reactor. This caused a break in the electricity supply and created a potentially hazardous emergency. The engineers of the Donetsk Research Institute proposed the solution of the problem.
They said that the reactor does not cool down immediately after shutdown. Similarly, the turbine, which operates under the influence of the residual steam pressure, does not stop its speed. In theory, the energy of this rotation may be used to generate the missing electricity in the amount of 45 seconds.
However, no one knew how long the rotation caused by the impulse of the turbine generator would last. Actually, nobody knew about it and the exact amount of energy that it might give. Donetsk engineers wanted to find the answer to these questions with the support of their Chernobyl colleagues. They planned to stop the 4th reactor in search of these answers. This was the essence of the experiment.
The complexity was due to the following. To conduct a test that had to improve the automatic shutdown mechanisms, these very mechanisms had to be turned off. This artificially simulated an interruption in the power supply and operation of the station.
Accordingly, there was a risk of losing control over the operation of the reactor directly during the test. But no one saw this as a problem. The station leaders had a great interest in conducting the test. Its results would have allowed them to master another method of emergency protection of the reactor, provided by its designers.
Moreover, the Ministry demanded the testing. Earlier, the personnel of the Chernobyl NPP had already tried to conduct such an experiment. However, it failed due to a malfunction of the steam turbine generator. The scientists solved the problem. Consequently, preparation for the test started in March and ended in mid-April.
Steam turbine testing was potentially the most difficult part of system validation. However, the planned repairs at the 4th reactor involved carrying out several more experiments. The disastrous outcome of the main experiment gave others no chance of implementation.