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2- The accident and immediate consequences


Unit 4 of the Nuclear power plant at Chernobyl explodes. Debris flies into the air and lands on the roof of Unit 3 which is right next to the exploded Unit 4. The units share a communal machine turbine hall with a roof of bitumen, a flammable ma-terial. Thirty fires develop. The fact that the accident happens at night has one great advantage: in the daytime, 2000 people are working on the construction of Chernobyl Units 5 and 6. These people are now at home. 

01.25 hours: The fire alarm rings at the local fire station. Meanwhile more people are killed: The nuclear plant's fire fighters arrive with three fire engines. The leader, Lieutenant Pravik, quickly realizes that his team is too small and asks the fire brigades from Pripyat, the town of Chernobyl and the entire area of Kiev for their assistance. Pravik and his team climb onto the roof of the machine hail and start their at-tempts to extinguish the fire. The fire brigade, from Pripyat arrives minutes later and fights the fires in the reactor building. Pravik and several firemen from Pripyat die later of radiation illness. 
01.45 hours: New teams of fire fighters from the area arrive. They know nothing about the danger of radiation, have no protective clothing or dosimeters. One of the fire engine drivers, Grigory Khmel later said: "We arrived at ten minutes to two in the morning. We saw graphite lying everywhere. I kicked a bit of it. Another fireman picked up a piece and said 'hot'. Neither of us had any idea of radiation. My colleagues Kolya, Pravik and others all went up the ladder to the roof of the reactor. I never saw them again." 
02.15 hours: The Pripyat department of the Ministry of Home Affairs calls a crisis meeting. It is decided to organize a road block in order to prevent cars from entering or leaving the town. Police assistance is requested. Thousands of police ar-rive; and, as with the fire fighters, they have no knowledge of radiation, no dosimeters or protective clothing. Later, in 1988, it is admitted that a total of 16,500 police were deployed. At that moment (1988) of those, 57 people had developed chro-nic radiation illness, 1500 of them suffered from chronic respi-ratory problems and 4000 suffered from other symptoms.
03.12 hours: An alarm signal goes off at the army headquar-ters in the central area of the Soviet Union at 03.12 hours. General Pikalov decides to send in troops to help. They arrive in Kiev at 14.00 hours. These are the first people to arrive well prepared for their task. About the same time, the responsible authorities such as the Energy Minister, A. Mayorets, hear that an accident has occurred, but are led to believe it is a small defect. 
05.00 hours: In spite of the fires, Chernobyl Unit 3 is not closed down until five o'clock am. 
06.35 hours: No fewer than 37 fire brigades, with a total of 186 fire fighters, have been called in to extinguish all the fires; the fire in the reactor could not actually be extinguished. The importance of the deployment of these fire fighters cannot be emphasized enough. The roof of Unit 3 caught fire immedia-tely, which meant that this reactor could have been seriously damaged as well. The nuclear plants' machine hell is also connected to Units 1 and 2. An explosion in the machine hall could have led to the destruction of all four Chernobyl reactors. An explosion was only averted by spraying nitrogen at the last minute. Four of the eight people who did this died shortly afterwards. 
20.00 hours: A government committee is established, led by Valery Legasov; at eight o'clock in the evening the committee arrives in the area. They are surprised by the bits of graphite they see lying around. None of them suspect a graphite fire. 

26 April to 4 May 1986: Most of the radiation is released in the first ten days. At first, southerly and southeasterly winds predominate. The first radioactive cloud went high into the atmosphere and winds blew it northwest away from Ukraine toward Sweden. It was Kiev's good fortune that the wind carried the radioactive cloud away at first rather than directly to the Ukrainian capital and its 3 million population as it did several days later. At the end of April the wind switches to the north and northwest. There are frequent but local showers. This results in a very varied regional and local distribution of the radiation. 

27 April (Sunday) 
A radius of 10 km around the plant (cities of Pripyat and Ya-nov) evacuated (“for three days” they are told) (50.000 people) to the town of Poliske (50 km west – coincidently -?- wind is blowing in that direction too). Dosimeters are confiscated. 01.13 hours: The operation of Units 1 and 2 had already been stopped at 01.13 and 02.13 hours, twenty-four hours after the start of the accident at Block 4 
07.00 hours: General Pikalov sets out in a truck fitted out with radiation apparatus. He rams through the closed gates and stops at the plant to measure the radiation. He establi-shes that the graphite in the reactor is burning, and that an enormous amount of radiation and heat is being given off. Shortly afterwards - the government in Moscow is warned. The government committee discusses the necessity of evacuation of the nearby town of Pripyat. Everyone supports evacuation except Professor A.L.Ilyin, chairman of the Soviet Council for Radiation Protection. He thinks the radiation situ-ation will improve. By now, as it is understood that graphite is burning and that radiation is being released, further steps are taken. Firstly, extinguishing water is added. This is a dangerous mistake. Due to the high temperature, the water separates into hydrogen and oxygen, and this mixture of gas can explode; an explosion like this releases heat. Thus, the fire is not extinguished, but fanned by the water. After three fruitless attempts to extinguish the fire, the authorities decide to throw sand, lead and boron carbide onto the reactor from helicopters. Boron carbide can absorb neutrons and stop the uranium fission. Lead absorbs heat, enabling the temperature to drop. Sand is to extinguish the fires. Between 27 April and 1 May, about 1800 helicopter flights deposit around 5000 tons of extinguishing materials such as sand and lead onto the burning reactor.

28 April (Monday) 
Forsmark NPP Sweden (times are Chernobyl-times) 
09:00 hours: An alarm was sent from Reactor 1, where a routine check revealed that the soles of the shoes worn by a radiological safety engineer were radioactive. 
Lars Wahlström, radiology supervisor at Forsmark, has given this summary of the events: 
"Something indicated that radioactivity had leaked out from one of the blocks at Forsmark. Rumors about the activity circulated between noon and 14hours and people said 'Now let's leave here.' At the same time news arrived that radioac-tivity had been detected in Finland. I said, I want evidence. Among other things I called Studsviks Energiteknik AB, where management was sitting in a crisis meeting and where they said 'We think it's coming from one of our laboratories.' But that wasn't so. Soon I also began to have doubts that there was anything wrong in any of the Forsmark reactors, which I told the National Institute of Radiation Protection. We had even been inside the chimney and checked. Then the Institute said the fallout had come from somewhere in the east, and by around 15.30 it was determined that the fallout definitely did not come from Forsmark." 
20:00 hours: Radio Moscow broadcasts a Tass’ statement that there has been an accident at the Chernobyl nuclear power station and that there have been casualties. “Measures are being taken to eliminate consequences of the accident. Aid is being given to those affected. A government  com-mission has been set up” according to Tass. From about 30 minutes later west-European news agencies are reporting an “incident in a Ukrainian nuclear reactor” 
23:00 hours: A Danish nuclear research laboratory announ-ces that an MCA (maximum credible accident) has occurred in the Chernobyl nuclear reactor. They mention a complete meltdown of one of the reactors and that all radioactivity has been released. 

29 April (Tuesday) 
- The sixth item on the main television evening news pro-gram, Vremya, says that 2 people died during the accident, a portion of the reactor building was destroyed, and residents of Pripyat and three nearby towns were evacuated. 
- The first real information in the western world came on Tuesday morning, when a powerful American reconnaissance satellite provided Washington analysts with photos of Cher-nobyl. They were shocked to see the roof blown off above the reactor and the glowing mass still smoking. The first Soviet photos of the Chernobyl accident were censored by removal of the smoke before being printed in the newspapers. 
- The first official statement by German authorities: Minister of the Interior Zimmermann states there is no danger for the German public: “danger only exists in a radius of 30-50 km of the reactor”. 
- Polish authorities decide to distribute iodine tablets in the north-east of the country to infants and children to protect them from thyroid cancer. 

30 April (Wednesday) 
- Tass carries a government statement denying western reports on mass casualties. The statement repeats the earlier assertion that only two people died during the accident and that 197 have been hospitalized and levels of radiation are decreasing 
- Press reports on fire in second unit: scientist see second fire on satellite images, claims are later denied 
17.00 hours: The reactor fire seems to be extinguished. 

May - December 1986 
1 May: The accident did not interfere with the May Day parades held on the 1st of May in the Ukrainian capital Kiev and the Belarusian capital Minsk. Apparently the government wanted to emphasize that all was "normal" although the reactor was still burning and invisible, deadly radioactivity was pouring into the air. However, the Soviet Communists bureaucrats and the nomenclature immediately after the ac-cident removed their children from Kiev and other threatened areas while assuring others that everything was normal until several days later 
- The authorities claim the situation is stable. But the amount of radiation released is still enormous, besides which, the wind has changed direction and is now blowing in the direc-tion of Kiev. The material thrown onto the plant does not com-pletely extinguish the fire and in fact generates a rise in tem-perature. Scientists and engineers become aware of a new danger. The hot reactor core could melt into the cement and end up in the water reservoir underneath. A steam explosion would follow, even more powerful than the first explosion. 
2 May: More and more radioactivity is released into the area. Fire fighters start pumping the water out of the storage reser-voir underneath the reactor, a long and dangerous task, not completed until 8 May. As a reward, the fire fighters receive 1000 rubles each (approximately 2000 US dollars according to the official rate of exchange). 
- Politburo members Ryzhkov and Ligachev visit Chernobyl. 
Ukrainian party leader Volodymyr Shcherbitsky visits the area also. Shcherbitsky survived the Chernobyl crisis and was not criticized in the Western press as was Gorbachov for his long 18 day delay in speaking publicly about Chernobyl 
- A 30 kilometer zone around the reactor is designated for evacuation (90.000 people). 
- According to the Russian permanent representative at the IAEA, chain–reaction inside the reactor has stopped 
4 May: The first film footage, shot from a helicopter, is shown on Vremya. The commentator says the film disproves Western reports of massive destruction 
- A second step taken to prevent a steam explosion is that of making holes in the earth under the reactor. Fluid nitrogen is pumped into them to freeze the earth. 
- Radioactive cloud reaches Japan (8-9,000 km from Chernobyl).
5 May: A government report says an embankment is being constructed on the Pripyat River to prevent it from being contaminated 
- To start with, there is a great deal of radioactivity released, nearly as much as on 26 April. However, the release later stops almost entirely. No acceptable explanation has yet been found for this fact. According to Grigory Medvedev, who was a member of the government committee, the fire was extin-guished because the graphite had burnt up. 
- Canada: health officials found that Ottawa rains carried six times as much radioactive iodine as is considered acceptable for drinking-water 
- Increased radiation levels are measured in the USA, too 
- Hans Blix, director-general, and a IAEA delegation arrives in Moscow. Unsure if the can visit the area 
6 May: The first extensive report on the situation appears in Pravda. 
- schools in Gomel and Kiev closed, all children are sent elsewhere. This brings total number of people forced to leave: 500.000. 140.000 of which are not allowed to return 
- Kiev radio finally, eleven days late, warned its audience not to eat leafy vegetables and to stay indoors as much as possi-ble. The Soviet government was very slow to warn its citizens of the precautions they should take: keep children and preg-nant women indoors, avoid fresh vegetables and milk, don't drink rainwater, and wash your clothes and your shoes every time you come in. 
7 May: Tass reports that many Kiev residents are trying to leave the city and that additional trains and flights have been scheduled. The (Russian) media drops its insistence that everything is under control. 
- Bavarian Environmental minister Alfred Dick criticizes maxi-mum radiation levels for vegetables and meat of the (German) Radiation Protection Agency. He says: “If we now start to have maximum levels for Cesium too, we will not even be able to eat meat shortly!” 
8 May: In an interview with Izvestiya, Academician Yevgeny Velikhov, vice-president of the Soviet Academy of Sciences and chief scientist sent to Chernobyl, says the disaster is 
“without precedent”. 
9 May: IAEA states that Moscow started to encapsulate the reactor, especially pouring concrete under the reactor, pre-venting it from reaching groundwater 
10 May: According to the IAEA the fire is extinguished, but temperature in reactor is still rather high. Meanwhile Ukrainian government official states: reactor is still burning and fire-fighters are continuously trying to put the fire out. 
11 May: three local officials  in charge of the transport com-bine at the plant, are expelled from the party, or reprimanded for mistakes concerning evacuations 
14 May: Gorbachov speaks for the first time publicly about the accident on Vremya.  He insisted there was no cover-up:  “The moment we received reliable data we gave it to the Soviet people and sent it abroad”. He declared his desire for "serious cooperation" with the IAEA, with respect to four specific proposals: 

  1. The creation of an international regime for safe development of nuclear energy involving close cooperation among all nuclear energy-using states; 
  2. A highly authoritative special international conference in Vienna under the aegis of the IAEA to discuss these "complex questions"; 
  3. An increased role and scope for IAEA;
  4. Safe development of "peaceful nuclear activities," involving the United Nations and its specialized departments, such as the World Health Organization (WHO) and the United Nations Environmental Program (UNEP).

These proposals suggested that Gorbachov was broadening the scope of the accident to one of international concern, but at the same time he was implying that such accidents were common enough to warrant the establishment of a global regime to deal with them. 

Mikhail Gorbachov
Mikhail Gorbachov had been in office only 13 months when Chernobyl occurred. He had arrived to a warm res-ponse from Western political leaders. Much younger and more active than his predecessors, he appeared to herald a time of change in the USSR. In 1986, however, he inherited an ossified Soviet state that was Leonid Brez-hnev's legacy. Gorbachov's reaction to Chernobyl was very cautious but, in addition to the defensive posture adopted by his government initially, he also indicated a willingness to cooperate with the IAEA. It should be noted that in 1985 the USSR had agreed to IAEA inspections of some of its nuclear reactors, and thus this policy was not necessarily a new departure. Similarly, aid offered from long-established "friends of the USSR" abroad was also accepted, while that of individual governments was turned down. 

15 to 16 May: New fires break out and more radiation is released. 
22 May: Russian First Deputy Health Minister denies popular believe that vodka (& red wine) is a good cure for radiation exposure. 
23 May: A Soviet government committee orders the distribu-tion of iodine preparations. At this point, such prophylaxis is of no medical value. Radioactive iodine is only active for ten days, and will already have accumulated in the thyroid glands of the inhabitants of the contaminated territories. 
27 May: A month after the accident the danger is not yet over,. A concrete foundation will be made, the idea of the sarcophagus is born 
30 May: An unprecedented concert took place in Moscow’s Olympic Stadium. The pop concert was organized by leading Soviet rock bands to raise funds for the Chernobyl victims 

Soviet authorities try to hush up the scale of the tragedy, admitting reluctantly that about 30 people had died in the first few weeks after the blast. Hundreds of thousands of people (many military reservists) from all over the Soviet Union, now popularly known as "liquidators," are mobilized by the Communist Party to clean up the disaster. 
The ‘Liquidators’ are those people who were recruited or forced to assist in the cleanup or the "liquidation" of the consequences of the accident. As a totalitarian government the Soviet Union forced many young soldiers to assist in the cleanup of the Chernobyl accident, apparently without sufficient protective clothing and insufficient explanation of the dangers involved. Over 650,000 liquidators helped in the cleanup in the first year. The total number is estimated to be over 1 million. Many of those who worked as liquidators became ill and according to some estimates about 8,000 to 10,000 have died in the first few years after the accident from the radioactive dose they received. Many more of these young healthy men died in the following years.

9 June: ‘By accident’ a foundation of lead was established under the reactor. Tons of lead thrown on the burning reactor, melted and leaked under the reactor. When the temperature decreased it solidified. 
15 June: Almost the complete management team of the reactor has been dismissed for ‘irresponsibility and lack of control’, Pravda announces. Amongst them Chernobyl Direc-tor Victor Bryukanov and deputies (senior engineer) Nikolai Fomin who will be brought on trial a year later. 
20 July: Report (which will be published in full later) of the Government commission of inquiry found that human error caused the disaster. 
20 August: The full report on the cause of the accident was submitted (in Russian) to the IAEA. It states there was an extraordinary sequence of carelessness, mismanagement and violations of safety codes leading to the accident.
26 August: Estonian press tell of strikes and demonstrations by Estonian military reservists forcibly conscripted Chernobyl for clean-up labor. In November reports claim 12 people were executed. 
20 September: The Soviet Union paid already US$3 billion, mainly for relocation, compensation and loss of power. 
29 September: Block 1 of the Chernobyl NPP restarts again, and connects to the grid on Oct. 1.
10 October: Construction-work on Block 5 & 6 is resumed. 9 November: Block 2 restarts.
14 December: A concrete roof ("sarcophagus") is completed over the fourth reactor. It is built to protect the environment from radiation for at least 30 years. 300,000 tons of concrete and 6,000 tons of metal constructions were utilized. 

March: Vladimir Chevchenko, a Russian filmmaker who made the documentary: Chernobyl, chronicle of frightening weeks, dies due to radiation illness 
21 April: Reactor 3 is supplying electricity again 
24 April: Construction work on Block 5&6 halted after it was resumed on Oct 10, 1986. On May 23, 1989 it is decided not to complete the reactors 
30 July: it was reported that three Russians, Chernobyl Direc-tor Victor Bryukanov and deputies Nikolai Fomin and Anatoly Dyatlov were brought to trial and "were found guilty of gross violation of safety regulations which led to the explosion" and were sentenced to 10 years in labor camp. They were released at the end of 1990. 
16 September: The Chernobyl disaster will cost the Soviet Union UKPounds 200 billion economic damage, a senior Moscow official disclosed. 
November: The U.S. government officially doubled its esti-mate of the ‘background’ radiation. 
5/6 December: Still problems with radiation escaping form reactor 4.

Norway increased the limit for cesium in reindeer meat for consumption to 6000 Bq/kg. This is extremely high. Sweden also increased their limit to 1500Bq/kg from 300Bq/kg in May 1987. Most countries have a limit of 600 Bq/kg. And even this figure is heavily criticized. But due to this limit much of the reindeer meat can be sold in Scandinavian countries 
5 January:  Block 3 (which shared a turbine-hall with Block 4) is restarted. 
February: In the period May-August 1986, between 20,000- 40,000 more Americans than usual died. Statistics can’t prove whether or not it was caused by Chernobyl, but “you can’t escape the fact that something happened in the summer of 1986” 
27 April:  Two years after the accident Valery Legasov commits suicide. He was the director of the Kurchatov Institute for Nuclear Energy, where the RBMK reactors were designed. He was also chairman of the scientific team sent to Chernobyl immediately after the accident on 26 April 1986  He left behind his memoirs in which he expresses his anger and des-pair about the safety of nuclear energy in the Soviet Union. He wrote that he wanted to study the safety problems of the RBMK reactors, and for this reason was opposed by people who said there were no problems. Legasov also wrote that there was a certain inevitability in working towards the acci-dent at Chernobyl. Valery Legasov was the head of the Soviet delegation presenting the research report to the congress in Vienna.. 
August: Sweden: With the opening of the deer hunting sea-son came alarming news. The Samen in northern Scandinavia are hard hit by the fall-out as there culture and livelihood depends on reindeer. The majority of animals killed contained more than the consumption limit of 1500 Bq/kg caesium-137. The level of cesium in lake fish has also increased over last year. 
September: Soviet authorities decided to turn the 30 km zone into a national park. All human activity, including farming is banned there. 
22 December: Soviet scientists announce that the sarcopha-gus now enclosing the reactor was designed for a lifetime of only 20 to 30 years. 

Start of the second resettlement phase. About 100 000 peo-ple have to leave their villages in the severely contaminated territories of Belarus, Ukraine and Russia. 
26 January: Politburo unexpectedly announced a new cam-paign (concentrated on Belarus) to cope with the consequen-ces of the disaster. 
February: The first maps highlighting radiation fallout from Chernobyl are published in the Soviet press. 
23 February: First visit of Soviet president Michael Gorba-chov to Chernobyl. He spends one hour at the site. 
May: Norway: According to the Isotope Lab of the Agricultu-ral University of Norway, 95% of radioactive elements are still present in upper soil layers and weathering processes within the next few years may increase the uptake of the Chernobyl fallout in the food chain (major grazing areas for livestock and domestic reindeer have been particular affected). 
23 May: Decision not to complete the two units under con-struction. Construction work on Block 5 & 6 resumed on Oct 10, 1986, and already halted on April 24 1987 
26 October: Tass reports that during the following year 100,000 people will be evacuated from contaminated areas in Belarus.