"A choir sang and the world watched as an engineer in a white lab coat switched off the last reactor at the Chernobyl power plant Friday, more than 14 years after it spewed a radioactive cloud across Europe, killing thousands in history's worst nuclear accident."" -NewsMax.
This came fourteen years too late for the residents of the Northern Ukrainian city, Chernobyl. This accident happened began one day after my birth, April 25, 1986. Although most high-school students were too young to remember the accident, this will probably affect them the most. To fully understand the significance of this accident we need to understand how a nuclear power plant works, events leading up to the explosion, and the future of nuclear power.
The Chernobyl accident began on April 25, 1986. They were shutting down reactor number 4 for scheduled maintenance. According to N. M. Formin, test were being carried out disregarding the safety system of the reactor; the nuclear equipment was supposed to be fully de-energized, the already spinning turbines would produce energy while the plant was down. The point of this test was to see if power was cut off to the equipment, which can happen in normal operations, would the plant still produce efficient energy. Nuclear safety during the test requires functioning of both the emergency reactor safety system (which has been bypassed), that is triggered when certain limits are exceeded and inserts control rods into the reactor core, and the emergency core cooling system. (G. Medvedev 32-33).
To better understand nuclear power you need to know how a nuclear power plant's reactor works. The source of power in the nuclear reactor is uranium ions. The uranium is formed into pellets with approximately the same diameter as a dime and a length of an inch or so. The pellets are arranged into long rods, and the rods into bundles. The bundles are then typically submerged in water inside a pressure vessel.