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 Belarussian
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 nomenklatura immediately after the accident 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 direction of Kiev. The material thrown
onto the plant does not completely extinguish the fire and in fact generates
a rise in temperature. 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 reservoir 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 Gorbachev for his long 18 day delay in speaking publicly about Chernobyl
- A 30 kilometer zone around the reactor is designated for evacuation
- 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 extinguished 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
- 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 possible. The Soviet
government was very slow to warn its citizens of the precautions they should
take: keep children and pregnant 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 critisices maximum radiation
levels for vegetables and meat of the (german) Radiation Protestion Agency.
He says: “If we now start to have maxumim levels for Ceasium 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, preventing it from reaching
10 May - Accordig to the IAEA the fire is extinguished, but
temperature in reactor is still rather high. Meanwhile Ukrainian goverment
official states: reactor is still burning and fire-fighters are contuiniously
trying to put the fire out.
11 May - three local officials in charge of the transport
combine at the plant, are expelled from the party, or reprimanded for mistakes
14 May - Gorbachev 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
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 Gorbachev 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.
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 distribution
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
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 popconcert was organised 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 mobilised by the Communist Party to clean up the
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 danger 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. This group apparently includes
those who built the containment building over the destroyed reactor No.
4 which is called the sarcophagus. More to follow in the time-line.
June: Overview of remedial actions taken in various countries
in the first weeks [pdf, 50 kb]
9 June - ‘By accident’ a foundation of lead was established
under the reactor. Tonnes 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 Director 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
labour. 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 utilised.