On March 21st, a Japanese government researcher reported that Japan Atomic Power Company had neglected to report new data from a sonic survey in 2005 which showed that the Tsuruga nuclear power plant in Fukui could be subjected to a more serious earthquake than previously estimated. Japan Atomic Power did not take oceanic faults into account when assessing the Tsuruga plant’s safety.
Earlier in March, Yuichi Sugiyama, leader of the team, said the Urazoko fault under the plant is at least 35 km long and could trigger a magnitude 7.4 quake. The research shows multiple faults exist 2 to 3 km from the Urasoko fault, according to Sugiyama, who is also on an expert panel of the Nuclear and Industrial Safety Agency.
The faults are highly likely to be activated at the same time, extending the length of the Urasoko fault to 35 km and magnifying its power, Sugiyama said. If confirmed, the location of the Tsuruga nuclear plant will be disqualified, an official of the nuclear safety agency said.
“The worst-case scenario should be taken into consideration” . Earlier predictions had estimated the fault could produce a temblor releasing less than half that amount of energy.
Japan Atomic Energy has failed to provide the data for studies undertaken by an expert panel launched in 2008 by the Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry.