By Ronald McCoy
Introduction
Since 11th March, Japan has been reeling from an unprecedented natural disaster of awesome proportions, followed by a man-made nuclear crisis. First, a record-breaking earthquake, 8.9 on the Richter scale, off the north-eastern coast of the Japanese island of Honshu. Then, a towering ten-metre tsunami which killed tens of thousands of people and destroyed almost everything in its path. Finally, the release of radioactivity into the environment from a nuclear power plant, damaged by overheating and explosions.
The earthquake had automatically shut-down the six nuclear reactors of the Fukushima Dai-Ichi nuclear power plant, owned by the Tokyo Electric Power Company (Tepco). But it also knocked out the power grid, forcing operators to fall back on diesel generators to keep coolant flowing into hot reactor cores of radioactive uranium and plutonium fuel rods. Then the tsunami swept in, knocked out the generators and cut off power to the plant’s cooling systems. All at once, four out of its six nuclear reactors were in dire trouble from overheating. Explosions then damaged fuel rods and the integrity of the primary containment structure, and radioactivity was released into the environment.
