A Nuclear Regulation Authority (NRA) panel report revealed that there is a high possibility that the Higashidori Nuclear Power Plant in Aomori Prefecture is built near a series of active faults. The fault line lies just 200 meters away from one of the plant’s reactor building at its nearest point.
The conclusion reached by the expert investigative panel is likely to put pressure on the plant’s operator, Tohoku Electric Power Co., to reassess the earthquake resistance of plant buildings and possibly reinforce them. While the faults in question do not run directly beneath the complex’s reactor building, the assessment indicates that the reactor unit may have to remain offline for a period of time the plant’s quake resistance reassessment. Nuclear plant operators are banned from building reactors and atomic power output facilities directly above active faults. It is quite possible that some of these faults were not detected upon initial probes, or failed to identify them as active at the time plants were built.
Officials of Tohoku Electric, who were also at the discussions, said the company will indeed conduct additional geological surveys, taking into account the results of the panel’s investigations. The officials though have maintained their argument that there are no active faults on the plant’s premises. Executive Vice President Takeo Umeda said one of the major purposes of the additional surveys is to “properly explain that there are no activities” in the faults.