TOKYO—When Tokyo Electric Power Co. broke ground on the now defunct Fukushima Daiichi nuclear-power station 44 years ago, the utility made a fateful construction decision that raised the plant’s vulnerability to the tsunami that ultimately crippled its reactors.
In 1967, Tepco chopped 25 meters off the 35-meter natural seawall where the reactors were to be located, according to documents filed at the time with Japanese authorities. That little-noticed action was taken to make it easier to ferry equipment to the site and pump seawater to the reactors. It was also seen as an efficient way to build the complex atop the solid base of bedrock needed to better protect the plant from earthquakes.
But the razing of the cliff also placed the reactors five meters below the level of 14- to 15-meter tsunami hitting the plant March 11, triggering a major nuclear disaster resulting in the meltdownof three reactor cores.
“It’s a typical act based on the thinking of the high-growth era. People were attracted to the idea of ‘reforming the land’ back then,” said seismologist Kazuo Oike, a former president of Kyoto University who now serves on a government committee investigating the Fukushima accident. “When you inflict significant change to nature,nature will eventually get back at you with a significant force.”