Fresh tales of chaos emerge from early in Fukushima nuclear crisis

The Fukushima Daiichi nuclear plant deteriorated in the crucial first 24 hours far more rapidly than previously understood, a Wall Street Journal reconstruction of the disaster shows.

So helpless were the plant's engineers that, as dusk fell after Japan's devastating March 11 quake and tsunami, they were forced to scavenge flashlights from nearby homes. They pulled batteries from cars not washed away by the tsunami in a desperate effort to revive reactor gauges that weren't working properly. The plant's complete power loss contributed to a failure of relief vents on a dangerously overheating reactor, forcing workers to open valves by hand.

And in a significant miscalculation: At first, engineers weren't aware that the plant's emergency batteries were barely working, the investigation found—giving them a false impression that they had more time to make repairs. As a result, nuclear fuel began melting down hours earlier than previously assumed. This week Tokyo Electric Power Co., or Tepco, confirmed that one of the plant's six reactors suffered a substantial meltdown early in Day 1.

Late Monday in Japan, Tepco released more than 2,000 pages of documents, dubbed reactor "diaries," which also provide new glimpses of the early hours. Soon after the quake, but before the tsunami struck, workers at one reactor actually shut down valves in a backup cooling system—one that, critically, didn't rely on electrical power to keep functioning—thinking it wasn't essential. That decision likely contributed to the rapid meltdown of nuclear fuel, experts say. ...