On 26 April 1986, one of the worst nuclear accidents in history occurred at the Chernobyl reactor in the Ukraine. The fourth reactor exploded in the early hours of the 26th and released radiation and particulate material, devastating a 20 mile (32 kilometer) radius and affecting to the rest of the world as well. The cause of the disaster was readily identified, and it was deemed by some nations to be gross negligence on the part of plant operators. There were 30 deaths at the site of the explosion, and many more people suffered illness as a result of radiation exposure.
The site of the Chernobyl reactor was cordoned off, and the reactor was capped with a large concrete pad. In the 21st century, it became evident that the pad was not effectively sealing off the radiation and that additional steps would need to be taken to prevent additional leakage of contaminated material. The area around the reactor is still restricted to humans, and in the slang of the region is known as the “dead zone,” despite the plant and animal life that has begun to take over the abandoned plant.
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The accident was caused by a routine shutdown at the power plant. The shutdown was designed to test the ability of the plant to function at low power, although other tests of similar plants and other reactors had suggested that powering down the plant was unsafe. The reactor became unstable as the flow of cooling water slowed, and because automatic shutoff had been disabled, the plant could not turn itself off. A worker realized the situation and attempted to turn off the reactor, but a power surge resulted instead, blowing the cover plate of the reactor off and showering radioactive material and particulates in a wide radius.
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Graphite from the core caught fire and burned for nine days, releasing a large amount of radioactivity into the atmosphere. Effects of the Chernobyl disaster could be felt all over the world, with many nations reporting a rise in radioactivity as a result. The area surrounding the plant was quickly evacuated, although personnel at the site, such as firefighters and medical staff, suffered from intense radiation exposure.
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The events at Chernobyl were a sobering lesson for the rest of the world, which realized that poorly maintained nuclear power plants could affect the rest of the planet and not merely the regions they were in. Citizens around the site continue to suffer the effects of radiation poisoning, requiring extensive public health monitoring and treatment. More stringent safety procedures at nuclear plants were instituted, with the aim of preventing similar catastrophic accidents.