On April 25th -26th, 1986 the World’s worst nuclear power accident occurred at Chernobyl in the former USSR (now Ukraine). The Chernobyl nuclear power plant located 80 miles north of Kiev had 4 reactors and whilst testing reactor number 4 numerous safety procedures were disregarded.

At 1:23am the reactions taking place in reactor 4 went awry and caused a massive steam explosion which blew off the reactor’s 1000 ton steel and concrete cap. Some of the 211 control rods melted and then a second explosion, whose cause is still the subject of disagreement among experts, threw out fragments of the burning radioactive fuel core and allowed air to rush in - igniting several tons of graphite insulating blocks. Once graphite starts to burn, its almost impossible to extinguish. It took 9 days and 5000 tons of sand, boron, dolomite, clay and lead dropped from helicopters to put it out.

The Chernobyl accident killed more than 30 people immediately, and as a result of the high radiation levels in the surrounding 20-mile radius, 135000 people had to be evacuated.