NRA to continue Oi fault probe

by Reiji Yoshida

Staff Writer

A panel of experts under the Nuclear Regulation Authority decided Wednesday to continue examining a fault running under the Oi nuclear plant in Fukui Prefecture, rejecting calls by one of its members that the facility immediately cease operations.

It was the panel’s second meeting since its members conducted an on-site geological survey Nov. 2 at the Oi complex, the only nuclear plant to be reactivated following the Fukushima disaster last year. As part of the survey, they examined the F-6 crushing belt fault that runs directly below critical pipes carrying coolant water for reactors 3 and 4 during emergencies.

The two units were restarted in July amid a public outcry.

If the fault is considered active, the NRA is likely to demand that all operations at the Oi plant immediately halt. However, the panel failed to reach a conclusion Wednesday.

At its meeting, Kansai Electric Power Co., which operates the Oi facility, issued a new 66-page interim report concluding that geological traces and analysis suggest the fault is not active and has not moved recently.

But Toyo University professor and panel member Mitsuhisa Watanabe argued the geological samplings are insufficient to support Kepco’s interim conclusion.

Watanabe, who believes the fault is active and potentially highly dangerous, demanded the panel curtail its technical discussions, but its deputy chairman, Kunihiko Shimazaki, declared it would hold further sessions, saying, “I don’t think we have reached any conclusion for now.”

Meanwhile, panel member Daisuke Hirouchi, an associate professor at Shinshu University, said he would prefer to conduct another on-site survey before arriving at a definitive conclusion.

The panel’s ultimate decision is likely to massively influence Japan’s atomic and basic energy policies, since strong antinuclear sentiment among the public has prevented the government from firing up any more reactors since the Oi units, and because crippling supply shortages are feared in the Kansai region if those two reactors were to be shut down.

Kepco claims it won’t be able to meet projected peak power demand if the Oi reactors are idled.