User:Moni3/Chernobyl
From Wikipedia, the free encyclopedia
thumb|right|300px|View of Unit-Four as it appeared following the explosion on 26 April 1986
The Chernobyl disaster was a cataclysmic explosion on 26 April 1986 at 1.23 am in a nuclear reactor at Unit-Four of the V. I. Lenin Chernobyl Nuclear Power Station located in the Ukrainian Soviet Socialist Republic. It occurred during a routine test in which the supervising engineer neglected to follow protocol, worsened by a fatal flaw in the design of the reactor the plant managers were unaware of. The result was a power surge resulting in a "slow explosion" in which 2,000 fuel rods and control channels were ruptured; intense heat inside the reactor combined with water, creating a steam burst that ripped off the concrete slab roof and sent a shower of steam and sparks an estimated 8 kilometres (5.0 mi) into the night sky.
Initially, Soviet authorities were unaware of the extent of the damage and how much radiation was leaked. Radiation censors near the plant stopped measuring at 200 roentgens an hour and no accurate measurement of how much radiation was released by the explosion is available. Radioactive graphite and other materials expelled from the reactor continued to burn for days following the explosion. The Soviet culture viewed nuclear energy as nearly infallible; other cultural factors such as secrecy and miscommunication through bureaucracy hindered a full understanding of how extensive and dangerous the explosion was. Soviet authorities narrowly defined the deaths resulting from the explosion. International organisations recorded 31 deaths from plant workers, firefighters, and others. Other sources estimate the dead to be as high as 2,000. Hundreds more were hospitalized with radiation poisoning.
As a result of the misunderstanding and miscommunication, nearly 50,000 people in the town of Pripyat, located 3 kilometres (1.9 mi) from the power plant where plant workers lived with their families, were evacuated 36 hours following the explosion after being exposed to dangerous levels of radiation. Within days the "exclusion zone" was widened to 30 kilometres (19 mi) surrounding the plant; eventually, 135,000 people were evacuated in the months following the accident. Winds carried radioactive particles over every part of Europe except the Iberian peninsula, and some parts of the Arabian peninsula and Greenland, forcing many European countries to put embargoes on food products. Over the next two years, about 600,000 people were involved in the clean-up and containment of Chernobyl. When machines failed from radiation contamination, a crew of "bio-robots", or people with makeshift radiation suits, were charged with removing the radioactive debris from the roof of the building. Another crew of miners dug a shaft under the building to install a liquid nitrogen cooling system to prevent another potentially devastating explosion that could have destroyed much of Europe. Unit-Four was eventually fitted with a structure referred to as the "Sarcophagus" that covered and insulated the damaged building. Many of the liquidators, or clean-up crew, suffered prolonged health effects from working so closely to radiation.
In a committed effort to share information about the accident, the Soviet Union provided a report about the details of the accident, but much of the information was distorted or withheld from other countries. Following the breakup of the Soviet Union in 1991, the remaining former Soviet Socialist Republics of the Ukraine and Belarus continue to deal with the effects of the radiation; an estimated 3.5 million people in the Ukraine bear physical effects from Chernobyl, including thyroid cancer and other health problems. As of 2010, Pripyat and several other towns close to the site of the explosion have not been repopulated. The accident at Chernobyl is the most severe to occur at a nuclear power plant as of 2010, and has been a significant factor in reassessing the viability of nuclear power throughout the world.