In April 1986, a nuclear disaster caused the evacuation of around 200,000 people from the cities of Chernobyl and Pripyat. Twenty-seven years later, there are still residents in Chernobyl, although Pripyat, a town closer to the accident site, is reportedly uninhabited. Due to the magnitude of this event, some may not want to believe that this disaster was unintentional, but many sources indicate otherwise. Some people will be surprised to learn that the Chernobyl disaster was caused by a safety test. In reality, there was concern that in the event of a power outage, the reactor core would overheat and allow tons of radioactive material to escape into the atmosphere. There were several safety devices to prevent this, but almost all of them were electronically controlled. So, in order to test the safety of the machine, the operators reduced the reactor to almost half its power and shut down one of the turbogenerators, because only one was needed. The mistake may have been shutting down the emergency core cooling system, or ECCS. Its objective was to shut down and cool a reactor in the event of a crisis. However, operators feared this would inject coolants into the extremely hot reactor and damage it. So they violated international security laws to keep it clear during the security test. As the test progressed, the operators disabled another safety device to reduce the power level. The experiment was lowered to a dangerous level, but the operators were asked to continue the experiment. Later, orders were received to deactivate the safety device that detected excessively high water levels. Eventually this caused a situation in which operators had to shut down the reactor, but fearing middle of paper ......., nd Web. January 1, 2014.Deadly Secret- Russia. YouTube. Journeyman Pictures, March 22, 2011. Web. January 10, 2014. Excell, Jon. “Building Chernobyl’s new safe containment.” Engineer (online edition) (2013): 13. Business Source Complete. Internet. January 5, 2014. Gale, Robert Peter. and Eric Lax. Radiation: what it is, what you need to know. New York: Random House, 2013. Print.Grapes, Bryan J. 1980-2000: The Twentieth Century. San Diego: Greenhaven, 2004. Print. Petryna, Adriana. “Chernobyl survivors: paralyzed by fatalism or neglected by science? Bulletin of Atomic Scientists 67.2 (2011): 30-37. Print.Read, Piers Paul. Ablaze: The story of the heroes and victims of Chernobyl. New York: Random House, 1993. Print. Schmid, SD “When sufficient security is not good enough: organizing security in Chernobyl.” » Bulletin of Atomic Scientists 67.2 (2011): 19-29. Print.