Utility seeks to overturn reactor ban

NRA judgment of active fault at Tsuruga plant challenged

Kyodo, JIJI

Japan Atomic Power Co. filed a petition Tuesday seeking to revoke the Nuclear Regulation Authority’s instruction issued in May to assess how spent-fuel assemblies would be affected by movement in a fault that runs under one of its reactors at the Tsuruga nuclear plant in Fukui Prefecture.

The move by Japan Atomic Power, which is angling to restart the Tsuruga reactors, is aimed at countering NRA’s conclusion that the fault is active.

This is the first protest filed by a power firm based on the administrative appeal law against the NRA since the regulatory body debuted last September.

A team of experts under the NRA compiled a report in May concluding that a crush zone under reactor 2 at the Tsuruga plant is an active fault requiring attention under seismic-resistant design guidelines for nuclear plants.

The NRA authorized the report and instructed the power company to submit an assessment by the end of July of how spent-fuel assemblies stored in a pool in the building housing reactor 2 could be affected by a quake.

In its objection, Japan Atomic Power requested the cancellation of the instruction, arguing that providing such an assessment would be tantamount to concluding the fault is active, which the firm denies.

The company argues that the NRA’s conclusion about the fault is mistaken and therefore the instruction based on it is illegal.

At the same time, the company said it will submit an evaluation report later this month as instructed because it can’t risk being penalized for not complying.

Last Thursday, Japan Atomic Power submitted a report to the NRA insisting that the fault shows no trace of movement during the past 120,000 to 130,000 years and therefore does not meet the definition of an active fault.

The NRA is now looking into that report.

Under the seismic-resistant design guidelines, no important structure in a nuclear facility can be built above an active fault.

Separately Tuesday, the NRA held its first meetings with power utilities to check whether their reactors satisfy the new safety requirements introduced following the 2011 Fukushima reactor meltdowns.

Four utilities have so far applied for the NRA’s safety assessments on a total of 12 reactors for which restarts are being sought.

The new requirements, introduced July 8, oblige utilities to put in place for the first time specific countermeasures against possible severe calamities, like reactor core meltdowns, as well as against huge tsunami — the direct cause of the catastrophe at Tokyo Electric Power Co.’s Fukushima No. 1 complex.