This morning, the Bloomberg News Service ran the clearest, most detailed piece I have seen on the damage at Fukushima Daiichi.
The writing is crisp, clear and terrifying. Here’s a sample:
What the earthquake had failed to to, the tsunami now achieved: It overwhelmed the engineering defenses at Dai-Ichi.
Seawater flooded the basements of turbine buildings and other sites, disabling 12 of the 13 back-up generators and destroying electrical switching units. Salt water shorted electric circuitry, depriving the reactos of power for cooling and triggering a nuclear disaster that Tepco was forced to combat with fire hoses and makeshift pumps.
“The level of flooding differed by building, but it was as high as 1.5 meters in one turbine room,” said Hikaru Kuroda, chief of Tepco’s nuclear facility management group.
At about 3:41 p.m., almost an hour after the quake, Dai-Ichi lost alternating-current power at the three operational reactos as the generators failed. Tepco immediately informed the government it had experienced “station blackout” as required by nuclear emergency regulations.
At this point, only battery power stood between the reactors and disaster:
The only defenses left to prevent Dai-Ichi’s nuclear fuel rods from overheating and spewing radiation were banks of so-called “coping” batteries designed to last no more than half a day. Once those were deployed to power emergency cooling, a nuclear plant would be, in the parlance of the industry, “12-hours coping.”
“What that means is the the clock has started ticking on restoring power before the batteries run out,” said Edward Morse, a professor of nuclear engineering at the University of California at Berkeley. Batteries buy several hours to “work miracles,” he said. Once the batteries start failing, if the cavalry isn’t there to bail you out, then you know you are really in trouble, he said.
I strongly encourage you to read this one in full. Here’s a link: