User:Aniket18601/sandbox

Chernobyl Effect

Chernobyl Accident 1986. The Chernobyl accident in 1986 was the result of a flawed reactor design that was operated with inadequately trained personnel. The resulting steam explosion and fires released at least 5% of the radioactive reactor core into the atmosphere and downwind – some 5200 PBq (I-131 eq).

Cause Of Chernobyl Accident

The 1986 accident at the Chernobyl nuclear power plant in Ukraine, then part of the former Soviet Union, is the only accident in the history of commercial nuclear power to cause fatalities from radiation. It was the product of a severely flawed Soviet-era reactor design, combined with human error.Key differences in U.S. reactor design, regulation and emergency preparedness mean that an accident like the one that took place at Chernobyl could not occur in the United States. The reactor built at Chernobyl is a RBMK reactor, which was never built by any country outside the USSR because it had characteristics that were rejected everywhere outside the Soviet Union. Chief among these was its inherent instability, especially on startup and shutdown. Because of the way the reactor used graphite where American reactors use water, when Soviet operators tried to reduce power the RBMK had a tendency to sharply increase power production instead. As overheating became more severe, power increased even more.

What Happened ?

The accident, which occurred at reactor 4 of the plant in the early morning of April 26, 1986, resulted when operators took action in violation of the plant’s procedures. Operators ran the plant at very low power, without adequate safety precautions and without properly coordinating or communicating the procedure with safety personnel. The four Chernobyl reactors were pressurized water reactors of the Soviet RBMK design, or Reactor BolshoMoshchnosty Kanalny, meaning “high-power channel reactor.” Designed to produce both plutonium and electric power, they were very different from standard commercial designs and employed a unique combination of a graphite moderator and water coolant. The reactors were highly unstable at low power, due to control rod design and “positive void coefficient,” factors that accelerated the nuclear chain reaction and power output if the reactors lost cooling water.