Soviet's Union Chernobyl

On April 1986, Soviet's Union Chernobyl nuclear plant exploded letting out a massive amount of radiation that would debate of all Russian citizens for hundreds of years to come. At exactly 1:21 am. on April, 1986 inChernobyl, a city near the Pripiat River the No. 4 reactor exploded and released thirty to forty times the radiation of the Nagasaki and Hiroshima bombing. The exact causes of the explosion are not known , however scientists and researchers, under thorough investigation, have uncovered possible causes to the explosion.1 The main reason why the explosion occurred was that, the operators of the plant were attempting to conduct an experiment with the emergency cooling system turned off, they made six fatal errors which sealed everyone's fate. Soviet officials clamed that if the technicians, would have avoided at least one of those mistakes, then the plant could have been saved.

The technicians began the test one day before the explosion. They started reducing the reactor's power level so they could run the turbine experiment. However in order for the plant to run at lower power they had to turn off the automatic control system, which powered all emergency limitations that the plant should make in case it goes out of control. Turning of the cooling system was an unnecessary action and though it did not cause the explosion, it made the consequences more fatal. Just then the operator's receive a call from the local grid controller in Kiev, who needed the power and asked the technicians to stop lowering it, at what they obeyed. Once that was done the reactor was running with out the cooling system , which was a very serious mistake. At 11:10 p.m. the grid controller said he no longer needed the power, and the operators returned to reducing the power. At twenty minutes past midnight the operators forgot to set the regulator properly, it was the second fatal error. Because of the incorrect regulator settings the reactor's power crashed to 30 MW from 1,000 MW which is too low for the test. At that point the operators would have abandoned the experiment, but they attempted to rescue it, for the next time they would be able to conduct would be in one year only. The senior authorities who had ordered the test would have been furious and would have found out the regulator problem. So the operators decided, to pull out the stops to restore the reactor's power.2 Their third fatal mistake, was the pulling out of control rods. The plant's rule was to have thirty in at all times however they left all but six. By 1:00 Am the power risen to 200 MW, which was still to low for the experiment, however the operators continued. In a few minutes they made their fourth fatal error, by turning on two extra pumps to join the six that wee already cooling the core. This procedure under such low power caused a massive steam disorder. Their fifth fatal error was the turning off of the automatic shut off, which would turn off the reactor. At 1:23 a.m. on Saturday April 26, the workers began the actual experiment. They made their sixth error, by turning off the last safety system. It took the shift manager thirty seconds to realize what was happening and shouted at another operators to press button AZ-5 which would driven all the control rods back into the core, but because the rods were melted from serious heat they didn't fit properly into the core. As the manager gloomy eyed looked down at the control panel several loud banging noises were heard. Immediately the one thousand tone roof of the reactor blew off sky high, and brought down the giant two hundred tone refueling crane onto the core, destroying more cooling systems and 30 fires spread around the plant. Finally the over-heating and steam build up caused a second explosion which destroyed the reactor and part of the building. The graphite began to burn ferociously once exposed to air, as core reached temperatures as high as 2,800o F a massive amount of radioactive dust was let out into the air which was picked by winds and carried thousands of miles into every direction. As well, previous to the testing the technicians, drew up plans, but did not discuss them with physicists or nuclear safety staff at the plant. Though they send experiment plans to the designers of the plant, the designers never got a chance to take a look and never issued any authority or made any confirmation. All soviet officials were certain that the explosion occurred not because of the plant, but because of human negligence. "The engineer who designed the plant and it's safety systems did not include such a scenario in his project" said Valeri Legasov, fist deputy director of the Kurchatov Atomic Institute. During an interview with Legasov, he stated that many discussions about the test have been going on and not everyone agreed to the test ever being conducted. However not everyone was satisfied with the ignorant technicians theory and