Fault check at Oi plant hit for lack of findings

by Eric Johnston

Staff Writer

The failure of a Nuclear Regulation Authority panel to conclude Sunday whether a fault underneath the Oi nuclear plant in Fukui Prefecture is active has created concern and alarm in Fukui and neighboring prefectures.

Panel head Kunihiko Shimazaki told reporters the fault dates from around 125,000 years ago and it is not a contradiction to think of it as an active fault. Under current guidelines, the government defines an active fault as one that has shifted during the last 120,000 to 130,000 years.

The panel will convene again Wednesday because it wants to hear from Kansai Electric Power Co. and discuss with experts the possibilities of landslides before reaching a final decision. This prompted criticism and concern from local officials.

“It’s critical to carry out the investigation and render a decision that everyone can understand, one based on objective data and scientific proof, but that’s not what we have. The members shouldn’t have these kinds of vague discussions,” Hiroshi Sakuramoto, a Fukui prefectural official in charge of safety, said Sunday evening.

“A fair and impartial investigation is directly tied to safety and peace of mind,” said Oi Mayor Shinobu Tokioka, who strongly supported restarting the Kepco plant’s reactors 3 and 4.

Concern about what might happen in the event the fault triggers an earthquake underneath the plant is especially strong in neighboring Kyoto and Shiga prefectures. The city of Kyoto has designated evacuation areas that can hold up to 160,000 people. But a large quake could trigger a need to evacuate as many as 300,000 people.

Towns in Kyoto Prefecture have held evacuation drills in the event of a meltdown crisis in Fukui. On Sunday, officials in Kyotanba, parts of which are within 30 km of the Oi plant, staged an emergency evacuation drill.