Test triggers nuclear disaster at Chernobyl
On April 26 1986 the worlds worst nuclear power plant accident occurs at the Chernobyl nuclear power station in the Soviet Union.Thirty-two people died and dozens more suffered radiation burns in the opening days of the crisis but only after Swedish authorities reported the fallout did Soviet authorities reluctantly admit that an accident had occurred.The Chernobyl station was situated at the settlement of Pripyat about 65 miles north of Kiev in the Ukraine.Built in the late 1970s on the banks of the Pripyat River Chernobyl had four reactors each capable of producing 1000 megawatts of electric power.
On the evening of April 25 1986 a group of engineers began an electrical-engineering experiment on the Number 4 reactor.The engineers who had little knowledge of reactor physics wanted to see if the reactors turbine could run emergency water pumps on inertial power.A view of the Chernobyl Nuclear power plant three days after the explosion. Considered historys worst nuclear accident the Chernobyl disaster on April 26 1986 killed 31 people directly many due to radiation poisoning during the cleanup.The area around the plant remains so contaminated that its officially closed off to human habitation.View the 10 images of this gallery on the original articleAs part of their poorly designed experiment the engineers disconnected the reactors emergency safety systems and its power-regulating system.
Next they compounded this recklessness with a series of mistakes They ran the reactor at a power level so low that the reaction became unstable and then removed too many of the reactors control rods in an attempt to power it up again.The reactors output rose to more than 200 megawatts but was proving increasingly difficult to control.Nevertheless at 123 a.m.
on April 26 the engineers continued with their experiment and shut down the turbine engine to see if its inertial spinning would power the reactors water pumps.In fact it did not adequately power the water pumps and without cooling water the power level in the reactor surged.READ MORE Chernobyl Disaster The Meltdown by the MinuteTo prevent meltdown the operators reinserted all the 200-some control rods into the reactor at once.The control rods were meant to reduce the reaction but had a design flaw graphite tips.
So before the control rods five meters of absorbent material could penetrate the core 200 graphite tips simultaneously entered thus facilitating the reaction and causing an explosion that blew off the heavy steel and concrete lid of the reactor.It was not a nuclear explosion as nuclear power plants are incapable of producing such a reaction but was chemical driven by the ignition of gases and steam that were generated by the runaway reaction.In the explosion and ensuing fire more than 50 tons of radioactive material were released into the atmosphere where it was carried by air currents.On April 27 Soviet authorities began an evacuation of the 30000 inhabitants of Pripyat.
A cover-up was attempted but on April 28 Swedish radiation monitoring stations more than 800 miles to the northwest of Chernobyl reported radiation levels 40 percent higher than normal.Later that day the Soviet news agency acknowledged that a major nuclear accident had occurred at Chernobyl.READ MORE ChernobylIn the opening days of the crisis 32 people died at Chernobyl and dozens more suffered radiation burns.The radiation that escaped into the atmosphere which was several times that produced by the atomic bombs dropped on Hiroshima and Nagasaki was spread by the wind over Northern and Eastern Europe contaminating millions of acres of forest and farmland.
An estimated 5000 Soviet citizens eventually died from cancer and other radiation-induced illnesses caused by their exposure to the Chernobyl radiation and millions more had their health adversely affected.In 2000 the last working reactors at Chernobyl were shut down and the plant was officially closed.
