Chernobyl (Ukraine) History and Disaster of Nuclear Contamination

Chernobyl (Tchernobyl) History and Disaster of Nuclear Contamination

Chernobyl (Tchernobyl)

Chernobyl is a city in Kiev Oblast, Ukraine. It is located 96 km north of Kiev. The city of Chernobyl is known for the disaster at the Chernobyl nuclear power plant, although this plant is located in the city of Pripyat 15 km northwest of Chernobyl, which took place on April 26, 1986 at 1:23 a.m. caused by the melting of the reactor. The disaster spread the radioactive equivalent of 400 times the Hiroshima bomb through the atmosphere [ref. necessary], or 0.5 times a current nuclear bomb and up to 4,000 people could ultimately die from radiation exposure following the accident, according to the WHO.

Chernobyl is included in the safety zone which surrounds the plant and which describes a circle with a radius of 30 km, supposed to be uninhabited and where only workers of the plant can move. However, some people have returned to live there. Some buildings were decontaminated to house the workers of the nuclear power plant and others were built according to very specific safety rules. The population of Chernobyl was around 500 inhabitants in 2010 and increased by 125 inhabitants in five years for a total population of 625 inhabitants in 2015. In 2016, there are 800 inhabitants and the population continues to grow. The P56 highway passes through the city and connects the city of Ivankiv to the city of Chernihiv via Belarus.

The Chernobyl tragedies were portrayed in a series named Chernobyl.


The name Chernobyl first appears in a charter from 1193 as the hunting lodge of Prince Rurik II of Kiev. The city, Czarnobyl, then passes under the control of the Grand Duchy of Lithuania and then of the Republic of the Two Nations. Jews settled there in the 17th century, making it one of the oldest Jewish settlements in Ukraine7. In the middle of the eighteenth century, Menahem Nahoum Twersky founded the Hasidic dynasty of Chernobyl there, now mainly established in the United States. At the end of the 19th century, the population of Chernobyl amounted to 9,303 inhabitants, including 5,526 Jews, or 59.4% of the total number of inhabitants7. Jews were the victims of pogroms there in October 1905 and May 1919.

Read also: Submarine | History and List of submarine incidents since 2000

The Ukrainian Soviet Socialist Republic was created in 1921 and on December 30, 1922, the USSR was born, bringing together Russia, Ukraine, Belarus and Transcaucasia. After the establishment of the communist regime, the Jews were still 3,165 (39% of the total) in 19267.

In 1932-1933, the city of Chernobyl like all the rest of Ukraine was severely affected by famine (the Holodomor), causing 3 to 7 million deaths throughout the country. The Polish community of Chernobyl was deported to Kazakhstan in 1936. Jews numbered only 1,783 in 1939 out of a total population of 8,4707.

The city was occupied by the Germans on August 25, 1941 and many Jews were massacred there on November 7, 1941. A few Jews were able to return there after the war and despite the hostility, there were still 150 Jewish families in 1970.

Chernobyl Reactor 4 model inside
A model of Chernobyl Nuclear Power Plant Reactor 4, on display in the Visitor Centre of the New Safe Confinement building. Photo credit: Wikimedia Commons

Chernobyl disaster

In the 1960s, Ukraine’s first nuclear power plant was built not far from Chernobyl, near Prypiat, a new town under construction between 1950 and 1970, the year it was founded.

On April 26, 1986, the explosion of reactor No. 4 at the Chernobyl plant in Ukraine (then part of the USSR) caused the largest civilian nuclear accident ever recorded (level 7 on the INES scale).

The accident was caused by the uncontrolled increase in the power of reactor No. 4, leading to the core meltdown. This causes the water in the cooling circuits to crack, then explode and release large quantities of radioactive elements into the atmosphere, causing widespread contamination of the environment, as well as many deaths and illnesses. occurring immediately or in the long term due to irradiation or contamination.

The event had significant health, ecological, economic and political consequences. More than 200,000 people have been permanently evacuated. The accident caused between 60 and 4,000 deaths according to reports from UN agencies published in peer-reviewed scientific journals2, or much more according to various analyzes by agencies or NGOs not published in scientific journals.

This accident released a radioactive cloud into the air, which spread mainly across Europe, with serious short and long-term consequences for populations and the natural environment in several countries.

Chernobyl shows that poorly controlled civilian nuclear energy can cause major damage to exposed populations and the environment.

Direct cause of Chernobyl explosion 

The accident occurred following a series of errors made by the technicians of the power plant in removing several safety devices under the orders of their superior and without analyzing the risks: “lack of sufficient preparation of the conditions necessary to the planned test, and due to a lack of time to carry it out, the operators did not comply with all the rules of conduct. They have also committed rule violations by inhibiting very important safety systems”.

In particular, the operators did not respect the procedures guaranteeing the control and the safety of the reactor, and, through ignorance, brought the reactor into a particularly unstable operating area; in fact, the RBMK presents in particular “a significant instability of the reactor at certain power levels [and] an excessively long reaction time of the emergency shutdown system” in particular a control rod insertion delay of 30 seconds in comparison of Western models less than 1 second (faults known to designers before the accident). It was this delay that made islanding tests essential and positive results absolutely necessary.

Chronology of the accident

A series of errors led to the explosion of the reactor.

At the start of 1986, 100,000 people lived in Chernobyl, around 100 kilometers from the capital Kiev (Ukraine). The city benefits from the economic boom of its nuclear power plant, commissioned between 1977 and 1983 and located nearly 15 km away.

  • The plant is made up of 4 reactors but does not have the safety equipment integrated in most Western plants, such as the double protective shell.
  • On the morning of April 25, a test of Reactor 4 is planned during a routine maintenance operation, under the orders of foreman Anatoly Dyatlov. This test of the emergency power supply consists of cutting off the power to the turbine in order to verify whether the latter would retain sufficient power to start the water pumps used to cool the reactor core.
  • On April 25 at 2 p.m. (local time), the reactor cooling system’s alarm system was disconnected in preparation for the test, in defiance of basic safety principles.
  • The power of reactor 4 was reduced as planned from 1,000 to 700 MWt, power reached on April 26 at 12:05 am.
  • The power then continues to drop, contrary to the conditions provided for by the test. On April 26 at 12:28 a.m., an operator error caused the reactor power to drop to 30 MWt. This causes poisoning of the reactor with xenon (accumulation of xenon-135, a fissile product which absorbs neutrons and disrupts the nuclear fission process.
  • At 1:23 am, the test on reactor 4 continues while the heart is very difficult to control. A series of mistakes and bad choices on the part of the crews causes the reactor temperature to rise. The mixture of hydrogen and oxygen, created by the radiolysis of water, causes small explosions that eject the reactor control rods.
  • According to the US Department of Energy, the Chernobyl explosion occurred on April 26, 1986 at 1:23 and 44s. The upper part of the reactor core ends up in the open air and the graphite catches fire. The fire is fueled by the intense heat released in the core, which is mainly due to radioactive decays of the fission products and which is no longer evacuated. He was not finally arrested until May 9. Dust and radioactive gases are released for 10 days.
    Two hours after the accident, the technicians of the surviving power plant experienced the first symptoms of radioactive contamination (malaise, vomiting, dizziness, diarrhea, burns). At 6 a.m., their condition was so alarming that they were taken to hospital. Several of them die in the days that follow.
  • On April 27, the first inhabitants of the nearby town of Pripyat were evacuated from the area.
    According to the TORCH report (drafted by the Greens / ALE in the European Parliament), the explosion released debris from the building and the reactor up to an altitude of 7 to 9 km. About 30% of the reactor fuel escapes in the immediate vicinity of the plant. About 50 tons of radioactive gas are ejected into the atmosphere, the equivalent of 200 times the fallout from Hiroshima and Nagasaki.
The intervention of “liquidators”

To contain the various fires at the plant, several firefighters intervene without effective protection against radiation.

According to the OECD, nearly 600,000 workers (2) took part in the Chernobyl clean-up operations between 1986 and 1991. These military and civilian personnel working on the site are called the “liquidators” and are cited as heroes of the nation. First, a kind of sticky paste is spilled by helicopter on the power plant to stick all the radioactive dust to the ground, then the workers destroy and bury the radioactive objects. Nearly 300,000 m3 of contaminated earth are thus buried under concrete.

Two months after the accident, the liquidators participated in the manufacture of a huge steel and concrete sarcophagus to protect the plant. As a precaution, robots are sent to the front line. But they are not resistant to radiation and break down, the emissions of radioactivity destroying their electronic components. Men are therefore sent to the site where they can only stay for 2 or 3 minutes at the risk of being irradiated to my body.

In November 1986, the installation of the sarcophagus was completed.

A cloud that spans all of Europe

On April 28, 1986, Sweden discovered the accident that had been ignored by Gorbachev’s government, due to abnormally high levels of radioactivity measured in the air. The USSR then made the accident public.

The radioactive cloud is moving over Europe, first affecting neighboring Belarus and Scandinavia. It crosses France then goes up to Luxembourg and Belgium. Part of the cloud then moves to the Netherlands and Scotland while another part extends to Corsica, Tunisia, Greece and Turkey. In a few weeks, the radioactive cloud covers an area estimated at 3.9 million km2, or about 40% of the area of ​​Europe.

The authorities facing the accident

Silence and procrastination of the Russian authorities

For several weeks, the Russian government underestimated the consequences of the explosion and carried out a campaign of disinformation. The first Russian press conference takes place 15 days after the accident and many Western journalists realize the cover-up of the situation by the Russian authorities.

Despite this accident, the Chernobyl plant continues to operate to everyone’s surprise. The authorities will wait until 1991 to shut down reactor 2 and the year 2000, i.e. more than 14 years before shutting down reactor 3.

Plant safety reviews

In Western Europe, Chernobyl is leading all states equipped with nuclear power plants to raise the level of security of their facilities and to review in detail the organization of nuclear security, in particular local emergency plans.

Various measures, in particular concerning the power supply, are taken on May 2 in many European countries (Poland, Denmark, Norway, Finland, Sweden, United Kingdom, Netherlands, Germany, Austria, Italy, Greece etc.) . Italy is setting up contamination control at its borders, with the aim of pushing back contaminated products from France where no measure has been decided.

In 1991, WHO created the International Program on the Health Effects of the Chernobyl Accident (IPHECA). Since that date, WHO has been purchasing and supplying drugs and medical equipment to Belarus, Russia and Ukraine.

Chernobyl rubble and steam tanks overlaid
Chernobyl rubble and steam tanks overlaid. The reactor lid (upper biological shield) nicknamed “Elena” lying on its side in the explosion crater. Overlaid are the pre-explosion position of the steam tanks, reactor hall floor and roof trusses.

Tadpolefarm, CC BY-SA 4.0, via Wikimedia Commons

Nuclear contamination

Since the disaster, recent buildings (1970s-1980s) in the city center have been decontaminated to accommodate the workers at the plant (around 5,000). The private houses of the old town are abandoned. The vegetation covers them little by little and gives the impression of a ghost town.

The city of Chernobyl is still “inhabited” but in a very special way since children and women who are pregnant or of childbearing age are not allowed there. Officially, a thousand inhabitants populate the no man’s land. Unofficially, it has three or four times more.

The radioactivity which had deposited in the form of spots decreased. But, in 2011, it still reached in places levels exceeding twenty or thirty times the authorized thresholds. On January 27, 2011, Ukrainian President Viktor Yanukovych (2010-2014) declared to the Secretary General of the United Nations, Ban Ki-moon, that he wished to resume the exploitation of contaminated agricultural land. However, a disappearance, or a reduction of the perimeter of the prohibited zone is unlikely to succeed as long as the International Atomic Energy Agency (IAEA) opposes it.

Air recontamination is particularly possible by fires such as that of April 2015 (approximately 400 ha) 8 or April 2020 which affected at least one hundred hectares located in the exclusion zone surrounding the power plant. , by generating an emission of radioactivity 16 times higher than normal, in the midst of the COVID-199 pandemic. At midday, Greenpeace says the fire is only “about a mile” from the arch used to cover the reactor that exploded in April 1986. According to Volodymyr Demtchouk, a senior official Ukrainian emergency services, “the Chernobyl nuclear power plant, radioactive waste storage sites and other crucial infrastructure in the exclusion zone are not threatened”.

35 years after the nuclear disaster, Chernobyl still attracts tourists

Before Fukushima, Chernobyl symbolized nuclear disaster. On the night of April 26, 1986, a reactor exploded. If a new dome has been built, no one can live in the area. The city of Pripyat (Ukraine) has become a ghost town but attracts people.

It is true that it is not similar Chernobyl and Fukushima neither from a power plant point of view nor from a nuclear accident point of view. BUT the impact of radioactivity on life at large exists in both cases. And that impact is undervalued when it disturbs.

It is a ghost town deserted by its inhabitants for 35 years. Pripyat, is located three kilometers from Chernobyl in Ukraine, site of one of the biggest nuclear disasters. To enter the area, you have to be patient, the place has become very popular with tourists. Each visitor shows their passport, signs a simple discharge and receives a Geiger counter to assess the amount of radiation observed. A day in the middle of the ruins of Chernobyl costs 135 euros. Such a success in 2019, the site welcomed more than 120,000 tourists, up 30%. “This is the only place in Ukraine where you feel like you are in the atmosphere of the Soviet Union at the time,” says Viktoria Brojko, a guide.

Soon to be a UNESCO World Heritage Site?

In Pripiat, before the incident, 50,000 people lived there, mainly employees of the nuclear power plant. On April 26, 1986, a reactor exploded and pulverized part of the building diffusing radioactive elements. Since then a sarcophagus has been installed on it and tourists can visit the control room where the disaster occurred. You don’t have to stay very long anyway. Ukraine relies on tourism in Chernobyl. The government has requested that the site be listed as a UNESCO World Heritage Site.

Sources: PinterPandai, World Nuclear, Britannica

Learn More →

Leave a Reply

Your email address will not be published. Required fields are marked *