Chernobyl: 20 Years Later

The Chernobyl nuclear disaster started 20 years ago on this date. The effects are still being felt today. Here's the chronology of events from Chernobyl.info:

1978 The first reactor of the Chernobyl nuclear power plant comes on stream. Chernobyl is considered a model plant in the USSR.

1983 Unit no. 4 of the Chernobyl power plant comes on stream.

1986: The year of the accident

• 26 April 1986, 1:23:00: A test of the cooling system begins in unit no. 4 of the Chernobyl power plant
• 26 April 1986, 1:23:40: The emergency shutdown fails.
• 26 April 1986, 1:23:44: The reactor in unit no. 4 runs out of control and explodes.
• 26 April 1986: In the town of Pripyat, 3 km away, there are 45 000 people, including 16 000 children. On 26 April 1986 they are enjoying the first warm Sunday of the spring.
• 26 April to 4 May 1986: Most of the radiation is released in the first ten days. At first, northerly and northwesterly winds predominate. At the end of April the wind switches to the south and southeast. There are frequent but local showers. This results in a very varied regional and local distribution of the radiation.
• 27 April to 5 May 1986: About 1800 helicopter flights deposit around 5000 tonnes of extinguishing materials such as sand and lead onto the burning reactor.
• 27 April 1986: The inhabitants of the Pripyat power plant settlement are evacuated.
• 28 April 1986, 21:00: The Soviet news agency Tass announces that there has been an accident at the Chernobyl nuclear power station and that there have been casualties. An investigative committee is established.
• 28 April 1986, 23:00: A Danish nuclear research laboratory announces that an MCA (maximum credible accident) has occurred in the Chernobyl nuclear reactor.
• 29 April 1986: The MCA at Chernobyl is first reported in German newscasts.
• Up to 5 May 1986: Over the ten days following the accident, 130 000 people are evacuated from a 30-km zone around the reactor.
• 6 May 1986: The release of radiation stops.
• 15 to 16 May 1986: New fires break out and more radiation is released.

The image is from a Belarus commemoration ceremony.