Japan Atomic Power overlooks data on fault beneath plant for 7 yrs

TOKYO (Kyodo) -- Japan Atomic Power Co. has overlooked for seven years data from its sonic survey of 2005 finding that a fault running under its Tsuruga nuclear power plant in Fukui Prefecture could trigger an earthquake more serious than anticipated, a government-affiliated researcher suggested Wednesday.

The importance of the data was confirmed through recent reexamination of them by a team of researchers at the National Institute of Advanced Industrial Science and Technology.

Earlier in March, Yuichi Sugiyama, leader of the team, said the Urazoko fault under the plant is at least 35 kilometers long and could trigger a quake with a magnitude of around 7.4, more than twice as much energy as earlier expected to be contained in a quake.

The research team estimated the length of the Urazoko fault by combining other faults connected to it, and the magnitude in expectation that the fault will cause a total displacement of more than 3 meters if it becomes active.

The government's Earthquake Research Committee and Japan Atomic Power earlier estimated that the Urazoko fault, including other faults connected to it, is 25 km long.

Japan Atomic Energy has failed to provide the data for studies at an expert panel launched in 2008 by the Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry.

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