Fukushima Emergency Power Failure Crippled Plant

Current Status of Fukushima (WSJ Graphic)

Fukushima Damage

The record earthquake and tsunami  that crippled the Fukushima nuclear power plant's emergency power supply far exceeded all engineering assumptions.  With no power, the pumps could not provide needed water to keep the reactors cool.  Depending on the damage to the spent fuel pools by the explosions, the lack of electrical power also prevented pumping water into those pools that lost their water.  Now at least one spent fuel pool is buring out of control.

The Fukushima Daiichi nuclear complex's back-up diesel-powered generators were built below ground level. This bunker-like positioning would protect the generators from an air strike, cyclone or typhoon—but made them more vulnerable to an earthquake-driven tsunami. When the giant waves struck, they immobilized the generators despite being designed to protect against water. The tsunami also apparently washed away the generators' fuel tanks, which were above ground. (WSJ, 3/17/2011)