30 Août 2012
Shikoku Electric Power Co. and Hokuriku Electric Power Co. told the government's Nuclear and Industrial Safety Agency (NISA) on Aug. 28 that the Ikata Nuclear Power Plant in Ehime Prefecture and the Shika Nuclear Power Plant in Ishikawa Prefecture can withstand earthquakes triggered by multiple active faults moving closely together.
The two power companies reported to a NISA expert panel that nuclear reactors and other key facilities at the two nuclear power stations would have no safety problems even if they are struck by earthquakes triggered by multiple active faults moving together. There was no objection to their arguments at the meeting, and therefore NISA is expected to endorse the reports.
At the expert panel meeting, Chugoku Electric Power Co. and Hokkaido Electric Power Co. also reported that the Shimane Nuclear Power Plant in Shimane Prefecture and the Tomari Nuclear Power Plant in Hokkaido would have "no problems" if they were struck by earthquakes under similar conditions. NISA is set to discuss whether their reports are credible.
Meanwhile, Tokyo Electric Power Co. (TEPCO) is in the process of evaluating the possible effects of active faults on the Kashiwazaki-Kariwa Nuclear Power Plant in Niigata Prefecture.
At the five nuclear power stations, tremors that can be triggered by active faults near the premises of the nuclear facilities moving together exceeded assumed maximum levels, or the standard earthquake ground motion, in some cycles of simulated ground motions. Therefore, NISA instructed the utilities verbally to assess the possible effects of active faults on key facilities at the nuclear power stations.