Tokyo Electric Power Company (TEPCO) officials yesterday said that a radiation monitor at the Fukushima nuclear plant sounded after the earthquake, but before the tsunami. TEPCO had said since the accident that the tsunami was the immediate cause of the subsequent meltdowns and partial meltdowns at the plant.
As Bloomberg.com reported this morning:
A radiation alarm went off at Tokyo Electric Power Co.’s Fukushima nuclear power plant before the tsunami hit on March 11, suggesting that contrary to earlier assumptions the reactors were damaged by the earthquake that spawned the wall of water.
A monitoring post on the perimeter of the plant about 1.5 kilometers (1 mile) from the No. 1 reactor went off at 3:29 p.m., minutes before the station was overwhelmed by the tsunami that knocked out backup power that kept reactor cooling systems running, according to documents supplied by the company. The monitor was set to go off at high levels of radiation, an official said.