It is known as a horrible accident in the entire history of mankind. This accident took place in 1986 at the Chernobyl nuclear power station in the Soviet Union . The Chernobyl nuclear power plant was situated near the city of Pripyat in the north of the . Ukrainian SSR The station was composed of four reactors each reactor produced about 1000 megawatts of electrical power. On April 26, 1998, this catastrophe occurred. This disaster occurred when technicians at reactor number 4 attempted a poorly designed experiment. In a reactor, there were a power-regulating system and emergency safety systems but workers, unfortunately, shut down them. They also draw out most of the control rods from their core while letting the reactor to work on 7 percent power. These mistakes were also added by others, and the chain reaction in the core went out of control at 1:23 AM on April 26. This results in several explosions which set off a big fireball and it blew off the heavy steel and co