Schools/Education
The Accident
The accident occurred as a result of the Soviet authorities’ insistence that on 25 April 1986 an experiment was to be carried out at the Chernobyl Power Plant. This experiment went radically wrong at 1.23 a.m. local time on 26 April when a number of fatal mistakes and procedural violations, including the withdrawal of control rods, led to a sudden power surge.
Within minutes, the reactor became highly unstable and the control rods were no longer able to balance and control the power surge. Although the station foreman gave the order to go into shutdown, his order came too late. Within four seconds, the power levels ran to 100 times its maximum rating for his kind of reactor, which led to a steam explosion blowing the roof off reactor number 4, which weighed 1,000 tons, as if it was the lid of a saucepan.
Three seconds later, with ruptured cooling system pipes and the control rods blown out, there was another explosion, during which the core of the reactor largely disintegrated. While the operators frantically pumped water into the remains of the shattered shell, it was to little avail because the reactor was now exposed to the air.
In the final seconds before the explosion, flames, sparks and chunks of burning red-hot nuclear fuel and graphite went flying into the air. Thundering noises came from all sides of the control room. There was one final colossal explosion, coming from every direction, which made it seem as if everything was bursting apart. A gigantic shock wave, carrying white dust, burst into the control room. The walls and floor of the control room crumbled, debris came crashing down from the ceiling and the lights went out, leaving only three emergency lamps. A flour-like dust invaded the operators’ mouths, noses, eyes and ears. Their mouths went dry. People saw the steam escaping and by the 27 April it had turned to smoke. The ensuing fire burned for 10 full days, consuming a minimum of 10 per cent of the reactor’s graphite core.
Click here to see the immediate aftermath of the disaster
