Tokyo Electric Power Co.’s department responsible for managing nuclear power plant facilities did not act on a risk of massive tsunami near the Fukushima Daiichi nuclear power plant projected in an in-house study in 2008, ruling out an immediate need to better protect the power station from seawater flooding, company sources said Sunday.
Despite the projection of a tsunami as high as 10.2 meters, officials of the department at the company’s headquarters insisted that such a risk was unrealistic, they said. In March, the power station was ravaged by a tsunami as high as about 15 meters.
Tsunamis triggered by the massive earthquake on March 11 flooded power supply facilities at the utility’s Fukushima Daiichi complex, crippling reactor cooling systems and consequently triggering nuclear fuel meltdowns.
The power plant was designed based on the company’s assumption that the biggest tsunami expected in the area would be 5.7 meters high. The 2008 study estimated that waters from a tidal wave that high would lead to an inundation height of 15.7 meters.
Some company sources say the utility, commonly known as TEPCO, could have been better prepared to cope with the tsunamis in March if it took the 2008 projection seriously.
The department supervising the nuclear facilities was set up in 2007, and had been headed until June last year by Masao Yoshida, chief of the Fukushima Daiichi power plant.
A TEPCO spokesman said the company intended to use the study for its facility management after the estimates in it were reviewed by a national civil engineering society.
– from mdn.mainichi.jp