33 years ago today: Chernobyl Nuclear Disaster

Considered the worst disaster in the history of nuclear power generation, the Chernobyl disaster occurred at the Chernobyl power station, located 10 miles northwest of the city of Chernobyl, in Ukraine. Starting on April 25, 1986, technicians at reactor 4 attempted a poorly designed experiment, while allowing the reactor to continue running at 7% power. Mistakes were compounded, and at 1:23 am on April 26 the chain reaction in the core went out of control. Several explosions triggered a large fireball and blew off the heavy steel and concrete lid of the reactor. This and the ensuing fire in the graphite reactor core released large amounts of radioactive material into the atmosphere, where it was carried great distances by air currents. A partial meltdown of the core also occurred.
The next day, the 30,000 inhabitants of the nearby village began evacuating. A cover-up was attempted, but on April 28 Swedish monitoring stations reported abnormally high levels of wind-transported radioactivity and pressed for an explanation. The Soviet government admitted there had been an accident at Chernobyl, thus setting off an international outcry over the dangers posed by the radioactive emissions. By May 4 both the heat and the radioactivity leaking from the reactor core were being contained, albeit at great risk to workers. Radioactive debris was buried at some 800 temporary sites, and later in the year the highly radioactive reactor core was enclosed in a concrete-and-steel sarcophagus (which was later deemed structurally unsound). Some sources state that two people were killed in the initial explosions, whereas others report that the figure was closer to 50. Dozens more contracted serious radiation sickness; many later died. Between 50 and 185 million curies of radionuclides (radioactive forms of chemical elements) escaped into the atmosphere—several times more radioactivity than that created by the atomic bombs dropped on Hiroshima and Nagasaki, Japan. This radioactivity was spread by the wind over Belarus, Russia, and Ukraine and soon reached as far west as France and Italy. Millions of acres of forest and farmland were contaminated, and, although many thousands of people were evacuated, hundreds of thousands more remained in contaminated areas. In addition, in subsequent years many livestock were born deformed, and among humans several thousand radiation-induced illnesses and cancer deaths were expected in the long term. The Chernobyl disaster sparked criticism of unsafe procedures and design flaws in Soviet reactors, and it heightened resistance to the building of more such plants. Chernobyl Unit 2 was shut down after a 1991 fire, and Unit 1 remained on-line until 1996. Chernobyl Unit 3 continued to operate until 2000, when the nuclear power station was officially decommissioned.
Following the disaster, the Soviet Union created a circle-shaped exclusion zone with a radius of about 19 miles centered on the nuclear power plant. This exclusion zone covered an area of about 1,000 square miles around the plant. However, it was later expanded to 1,600 square miles to include heavily radiated areas outside the initial zone. Although no people actually live in the exclusion zone, scientists, scavengers, and others may file for permits that allow them to enter for limited amounts of time.


By: Vyky (4089.00)

Tags: Chernobyl, nuclear, nuclear disaster, accident, nuclear accident, radiation, meltdown, USSR, Soviet disaster

Location: Chernobyl, Ukraine, Soviet Union