Individual involvement in the Chernobyl disaster

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The Chernobyl disaster was a catastrophic nuclear disaster rated a level 7 accident on the International Nuclear Event Scale, the highest possible rating. The Fukushima nuclear accident, also rated level 7, is the only other level 7-rated accident.

The accident occurred at 01:23 MSD on April 26th, 1986, at the Chernobyl Nuclear Power Plant in Soviet Ukraine. The accident occurred during an intended safety test for Reactor Number 4; the conditions of the test accidentally triggered the power to drop, and then surge. This caused an explosion and destroyed most of the reactor building due to operator error and reactor design flaws. The explosion spread debris and radioactive material across the surrounding area, and over the following days and weeks, most of mainland Europe was contaminated with radionuclides that emitted dangerous amounts of ionizing radiation. On the night of April 25th and the early hours of April 26th, there had been 160 personnel on duty across the facility, while 300 more workers were on site at the building site of reactors 5 and 6.