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AP Exclusive: Fukushima tsunami plan a single page



TOKYO  Japanese nuclear regulators trusted that the reactors at the Fukushima Dai-ichi complex were safe from the worst waves an earthquake could muster based on a single-page memo from the plant operator nearly a decade ago. In the Dec. 19, 2001, document  one double-sized page obtained by The Associated Press under Japan's public records law  Tokyo Electric Power Co. rules out the possibility of a tsunami large enough to knock the plant offline and gives scant details to justify this conclusion, which proved to be wildly optimistic.

Regulators at the Nuclear and Industrial Safety Agency, or NISA, had asked plant operators for assessments of their earthquake and tsunami preparedness. They didn't mind the brevity of TEPCO's response, and apparently made no moves to verify its calculations or ask for supporting documents. "This is all we saw," said Masaru Kobayashi, who now heads NISA's quake-safety section. "We did not look into the validity of the content." The memo has Japanese text, boxes and numbers. It also has a tiny map of Japan indicating where historical earthquakes are believed to have struck. TEPCO considered five quakes, ranging from 8.0 to 8.6 magnitude, in northeastern Japan, and a 9.5 magnitude across the Pacific near Chile, as examples of possible tsunami-causing temblors.

In the next nine years, despite advances in earthquake and tsunami science, the document gathered dust and was never updated. When TEPCO finally did revisit tsunami preparedness last year, it was the most cursory of checks. And the conclusion was the same: The facility would remain dry under every scenario the utility envisioned. "There was an attitude of disrespecting nature," said Kobe University professor emeritus Katsuhiko Ishibashi, who has sat on government nuclear safety advisory panels.


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