- Historical event:
- 26 April 1986
- It seems that the error was that the system check was conducted by inexperienced technicians, during the night shift when demand for power in Ukraine was not high. The power plant managers, who might have been able to prevent the disaster, were not present.
On this day in 1986, the greatest nuclear disaster in recorded world history occured. Reactor number four exploded at the Chernobyl nuclear power plant, about 110 kilometers north of the Ukrainian capital Kiev.
The explosion occurred during a reactor security check. The error was, it seems, that the testing was carried out by insufficiently experienced technicians, during the night shift, when the demand for power in Ukraine was not high.
The power plant managers, who might have been able to prevent the disaster, were not present.
It is paradoxical that the explosion occurred only when a technician pressed the button for the complete shutdown of the reactor.
Graphite moderator rods then entered into the hot core, edging out the coolant. The result was that the core got warmer in a short time, which produced gases that blew the lid of the reactor.
The pressure was so strong that it knocked off the 2000-tons top panel. The graphite moderator rods were set on fire, and a large amount of radioactive substances was released into the atmosphere.
In total, 350,400 people were evacuated. 31 people died in the plant, but it is estimated that about 4000 people who participated in the rescue or lived in the area subsequently died from exposure to radiation.
Greenpeace estimates that more than 200,000 people could die of cancer caused by the Chernobyl disaster.
About 60% of the radiation fell on Belarus, because the prevailing winds after the accidentwere to the north and northwest.