The Chernobyl nuclear power plant accident occurred on April 26, 1986. It was the largest nuclear energy disaster in history. The explosion took place in the fourth block of the Chernobyl power plant, located only 120 km from the capital of Ukraine – Kiev, close to the border with Belarus.
Chernobyl power plant was at that time one of the largest in the world. It was dedicated to a strategic military program for the Soviet army. The actual crash happened due to a coincidence of several factors. Beside the fact that the reactor did not have an updated security system, it had a low level of automation. On the fatal night of April 26, there was an experiment going on, which should have tested the inertial range of the turbo-generator unit. Overheating fuel caused the destruction of the generator’s surface.
At 1:24 AM local time, 40-60 seconds after commencing the experiment, two large explosions took place. According to some accident investigators, taking off all the absorbing sticks from the active zone of the reactor, together with the reactor’s growing power capacity, the crash was unavoidable. It was recorded that safety systems were shut off or even out of service at the time of the initial explosion and the explosion of steam and hydrogen blew the 1200 ton cover of the reactor and destroyed the roof. After a few seconds there came the second explosion. According to several independent studies, while the first explosion was normal – chemical, the second explosion with the burning of the prompt neutrons, it had characteristics of a nuclear explosion with a yield of 0.3 kilotons (equal to around 300 tons of TNT). According to witnesses the first explosion was followed by a red blaze and the second explosion had a light-blue blaze, after which a mushroom cloud rose above the reactor.
The nuclear disaster was also a coincidence and the reactor should have been shut down before the experiment could begin. However, this was postponed by nine hours because of the forthcoming May 1 celebrations and the electricity needed to fulfill the production plan. This delay meant that the experiment had to be managed by a different shift than the one which prepared it. The night shift conducting the experiment comprised fewer experienced operators.
After The Disaster
Radioactivity started to radiate out of the destroyed and burning fourth reactor of Chernobyl power plant, which contaminated both the near and far environment. The investigation of Chernobyl disaster was officially closed with a result that the personnel of the power plant did not follow the necessary safety regulations. Lenin Nuclear Power Plant was just the beginning of an aftermath that re-wrote not just the safety rules in nuclear energy, but also the history of mankind. Radioactivity started to radiate out of the destroyed and burning fourth reactor of Chernobyl power plant, which contaminated both the near and far environment.
The first step in liquidation of the nuclear accident at Chernobyl was extinguishing the burning reactor hall and the roof of turbo-generator’s hall. Special power plant fire department, together with firemen from the nearby town of Chernobyl, extinguished the fire within three hours after the explosion. Yet, in the heart of the reactor, graphite was still burning…
Firemen who worked at the accident did not know the cause of the fire and thus they just poured water at the ruins of the reactor. This worsened the situation and several smaller explosions followed, together with a severe radioactive contamination. To prevent radioactivity from further spreading into the environment, the reactor was filled with five thousand tons of boron, dolomite, sand, clay and lead compound - thrown from a helicopter flying above the reactor. These loose materials extinguished the burning graphite and absorbed radioactive aerosols. Two weeks after the breakdown, Soviet official bodies decided to conserve the whole crashed block of the power plant into a special sarcophagus – concrete body with its own cooling system.
The explosion at Chernobyl brought up radioactive substances to the altitude of 1.5 kilometer in the air. In this elevation, wind from the southeast took the radioactive cloud to as far as Scandinavia. The cloud flew over Scandinavia and then turned back to Ukraine again. During the day of the accident, the direction of the wind changed to westward. The second contaminated cloud thus flew via Poland to Czechoslovakia and further to Austria. There, it bounced back from the Alps and flew back to Poland. As far as we know today, there is no place in the world where the radioactive clouds from Chernobyl were not present. Contaminated clouds flew all around the world.
The most affected territories were Ukraine and Belarus, which decided to evacuate parts of their countries forever because of the contamination of the environment. In the process of contamination, a large role was played by radioactive iodide. This element has a short disintegration half-time and relatively soon after the accident naturally decomposed to harmless substances. Today, the radioactive pollution is made up mostly by substances such as strontium and cesium – these have a 30-year disintegration half-time. Thus, they will continue to pollute the close environment for several decades. Isotope of plutonium and americium will be present at the respective territory probably for several thousand years. However, they have a negligible radiation affect for the human body.
Victims of the accident
The facts divide upon the number of victims of the Chernobyl crash. Of course, the direct victims were mostly the plant workers as well as the firemen, who received deadly doses of radiation. Most of the direct victims are buried at the Mitino cemetery in Moscow. Each body is sealed in concrete coffin, because of its high radiation.
Radioactive pollution spread mostly to the nearby town of Pripyat. This town was erected for power plant workers only three kilometers from the nuclear power plant. During the whole day after the accident, the state officials had not warned the 50 thousand inhabitants about the threat of radioactive pollution. Neither had they provided them with iodine pills helping against the radiation. The power plant accident caused the level of radiation to exceed the natural levels by thousand times. Evacuation of Pripyat took place the day after – on the afternoon of April 27, 1986. The inhabitants were allowed to take only necessary items with them, so as to return in three days. By the time they were evacuated, they were all exposed to large amounts of radiation.
Officially, the Chernobyl disaster affected lives of about 600,000 people. Official documents divide the victims of radiation into several categories. For example, there is the largest group of 200-240 thousand liquidators – rescuers, soldiers that have done decontaminating works, firemen as well as police officers. Moreover, there is the group of about 116 thousand inhabitants of the polluted areas near Chernobyl. Other 220 thousand people were evacuated later from the polluted territories of Belarus, Ukraine and Russia. Still, around 5 million people continue living in the polluted areas at the moment.
Pripyat – City of Ghosts
Pripyat was once a model city of the Soviet government and was erected in 1970 for the workers of the nuclear power plant, situated just three kilometers away. The average age of the city inhabitants was, by the time of the accident only 25 years old. Pripyat had all the luxuries of a modern city – a railway station, port, hospital and a fairground.
The day after the Chernobyl accident, the state officials still had not warned the 50 thousand inhabitants about the threat of radioactive pollution; neither had they provided them with iodine pills helping against radiation. The power plant accident caused the level of radiation to exceed natural levels by a thousand times. Evacuation of Pripyat took place the day after – on the afternoon of April 27, 1986. The inhabitants were allowed to take only necessary items with them, as they were to return in three days. This information was released to avoid panic and to stop people taking too much luggage with them. Later, the authorities decided that the city must remain empty forever.
During the evacuation women and children were collected first, but there was a serious lack of busses in this part of the Soviet Union. The busses thus had to come from other parts of the country to evacuate all 50 thousand inhabitants of Pripyat. The queue for the busses was 120 kilometers long – which means that when the first bus was leaving Pripyat, the last bus couldn’t even see the power plant chimneys from the distance away. In less than three hours the city was empty, and this way it will stay forever.
During the evacuation, the people of Pripyat were not allowed to take pets or cattle with them, this was due to the fact that these animals could have had their furs contaminated with radioactive dust. Also, to avoid contamination of the environment, special forces had to liquidate every animal in the Chernobyl zone. On May 5th, the evacuation of people living in the exclusion zone (30 km radius around Chernobyl) was finished. Today, the zone is forbidden for people to enter, with the exception of ex-residents visiting cemeteries or those with a permit. Around 100 people (mostly pensioners) live in this exclusion zone and all are all living here at their own risk. Apart from these inhabitants, there are also around 3000 workers whom are in special regime and take care of the Chernobyl zone itself. The same quantities of workers are still working at the Chernobyl power plant, even though it has been completely shut-down since 2000. Besides liquidating the nuclear fuel, these workers also continue with the construction of the new sarcophagus, planned to be completed in 2016.
Pripyat is now a city of ghosts and despite nobody living there, it has its own grace and atmosphere. Pripyat did not end like the nearby villages which were buried under the ground by bulldozers. The villages are commemorated only by boards on the road with their names and a village map. Pripyat, as well as the whole 30-kilometer restricted zone is guarded by the Police and Army. Despite this non-stop duty, it did not prevent robbery and plunder, mostly in 1991 after the Soviet Union dissolution when the Chernobyl zone was unwatched. The whole city of Pripyat is plundered and there isn’t a single flat that has not been visited by thieves, taking away all precious items to be found. A military factory (named Jupiter) had been operating in the city until 1997; today it is even more plundered and destroyed than the majority of flats or schools in the city. The city is full of contemporary (that is 1980s) writings, signs, books or pictures, mostly with Lenin motives. Lenin’s statements and portraits are virtually everywhere – in the Palace of Culture, in the hotel, the hospital, at the police station, as well as in the schools and kindergarten. The walk around the city is like a trip back to the past, the only difference is that there’s not a single soul around, not even birds in the sky! One can only imagine the whole picture of the era when the city was booming. The whole city was erected on a green field soon after the nuclear power plant was built. Everything is made out of concrete and the houses look the same as in any other city of the Soviet origin. Some of these buildings have been overgrown with trees and are barely visible from the road. Chernobyl is a vital example of how Mother Nature can cope with the work of Man. In just over two decades only ruins remain from the city. There is no other such place in the world.
Safety and Radiation Today
There are still radioactive places in the Chernobyl zone, although the levels are now a fraction of the radiation levels from 1986. Much of the radioactive isotopes have gone deeper into the soil. Every year they decrease by around one centimeter. Radiation and its intensity at Chernobyl is not harmful or dangerous for human health today.
During two days in the Chernobyl zone, the human body receives a radiation dose equal to one X-ray screening in a hospital or to one intercontinental flight (radiation in the airplane). In numbers, it means that during a two day Chernobyl tour one will get a dose of radiation around 4 microsieverts (a safe limit is 100 microsieverts per day). Visitors to the Chernobyl exclusion zone should avoid radioactive dust, which might occur at some places and get stuck in small (not dangerous) amounts on their clothes or shoes. Due to this fact, CHERNOBYLwel.come suggests that all visitors wash all their clothes and shoes after they return home. Every adventurer travelling with CHERNOBYLwel.come will get a fabric respirator for free.
More on Radiation
Radiation is energy that moves through space. It comes in the form of particles or waves. Some of the radiation types – mostly those which are the result of nuclear or radioactive actions – can be harmful to the human body and health in large amounts. Visitors of the Chernobyl exclusion zone will have some contact with gamma radiation present in some places in Chernobyl and Pripyat. This radiation is disposed out of the human body pretty quickly. Beta radiation, which stays in the human body forever, is located only close to the reactor shell. Thus, the expedition to Chernobyl is safe to take photos from a safe distance, while staying in front of the reactor area for only a short amount of time. Visitors to the Chernobyl exclusion zone will not be in contact with the most dangerous alpha radiation. Penetrating abilities of these types of radiations are different.