Chernobyl was one of the largest and most powerful nuclear reactors in the former Soviet Union. It was used to power the part of the U.S.S.R now known as Ukraine. Also it was thought of as one of the safest nuclear reactors in the world. But on April 26, 1986 something went terribly wrong and it is now thought of as the worst nuclear disaster in history. It killed over 100,000 people with its radiation and is still expected to contribute to the deaths of over 300,000 people.
             This disaster was caused by a number of things including negligence. On April 25, 1986, the day before the accident a test was scheduled to take place. This test was to see if the emergency systems would work properly in case of power loss. At 1:00 am the Soviet made RBMK class reactor was running at full power with normal conditions. Then the operators slowly began to reduce power in the reactor. Then the scientists waited twelve hours while reducing the power until it was at 50% of normal. Now that the power was lower the Number Two turbine was switched off because it was not needed to take in the smaller amount of steam.
             Normally during the test the power would have been further reduced to 30% but the Soviet Power Authority would not allow this because of the vast amount of electricity needed to power that part of Ukraine. On April 26 at 12:28 AM the staff received permission to resume the reactor power reduction. But one of the operators made a fatal mistake. He forgot to reset a controller that would have kept the power at 30% of normal. This caused the power to fall to 1% and water started to fill the core, also xenon, which is a neutron absorber, started to build up. Then the water that was filling the core was heated and turned into steam by the nuclear reaction. The operator then decided to remove all of the controller rods from the core to force the power to 7%. This was a direct violation of safety rules and the reactor became very unstable becaus...