Level Seven Scenario: Sirens blaring in the dead of night and chaos erupting from every direction. At exactly 1:21 am on April 26, 1986 in Chernobyl, in a city of more than fifty thousand people located near the Pripiat River, a reactor exploded and released thirty to forty times the radiation of the bombings of Hiroshima and Nagasaki. But one would never think that a disaster of this magnitude could ever happen because the workers at the plant are among the most highly trained in the universe. Millions of people had to suffer the largest nuclear disaster ever known to humanity. The Chernobyl Site Located about 81 miles north of Kiev, Ukraine, and about 12 miles south of the border with Belarus, the Chernobyl plant consisted of four RBMK-1000 (Bolshoy Moshchnosty Kanalny Reactor) nuclear reactors. Reactors one and two were built from 1970 to 1977, while reactors three and four were completed in 1983. Before the nuclear accident occurred, two more reactors were built to have better energy production. An approximately 236,808,000 square foot artificial lake was located just southeast of the plant where a tributary was constructed to flow cooling water for the four reactors. The RBMK-1000 is a Soviet-designed and built moderate-pressure graphite tube reactor. It is designed to slow neutrons and make them more effective at producing fission in the fuel surrounding the pressure tubes. The energy production of this reactor is 3200 MW (megawatt) thermal. Many safety systems such as the emergency core cooling system have been integrated into the reactor design. One of the most important features of the RBMK reactor is that it can contain a "positive vacuum coefficient". That's... middle of the paper... chain reaction and energy production could increase if cooling water was lost or turned to steam, compared to most Western designs. Since 1989, over 1,000 nuclear engineers from the Soviet Union have visited Western nuclear power plants, and there have been many mutual visits. More than 50 similar provisions have been adopted between nuclear power plants in the East and West. Many other international programs were started after the Chernobyl disaster. The International Atomic Energy Agency (IAEA) evaluates safety designs for each particular type of Soviet reactor, bringing together Western operators and engineers to focus on safety improvements. The Chernobyl Committee report states that up to six million people receive or are entitled to benefits as "Chernobyl victims". We are slowly rebuilding from this horrendous disaster, but together we can learn and overcome it.