The Nuclear Regulation Authority said at a safety screening meeting Friday that it has confirmed active faults at the site of the No. 1 reactor at Tohoku Electric Power Co.’s Higashidori nuclear plant and will base discussions on the restart of the idled reactor on the assumption that the faults will move.
Tohoku Electric, which has denied the existence of such active faults, may be asked to reassess the earthquake resistance of the reactor in Aomori Prefecture, people familiar with the matter said.
In March, a team of experts said in a report to the authority that two major faults called F-3 and F-9 that run near the reactor could move in the future.
At Friday’s meeting, the NRA also offered the view that separate faults similar to the two at the site will likely move as well.
The authority has yet to conclude whether a minor fault running under a cooling water intake channel, a key safety facility for the reactor, is active or not.
If the fault is determined to be an active one, Tohoku Electric will be ordered to decommission the No. 1 unit, as the new nuclear safety standards, introduced in July 2013, prohibit the installation of key facilities, including reactors themselves, over active faults.
The Higashidori plant is the second nuclear power station confirmed by the NRA to have an active fault at its site, after Japan Atomic Power Co.’s Tsuruga nuclear plant in Fukui Prefecture.
Tohoku Electric hopes to reactivate the 1.1-million-kw No. 1 reactor, which went offline in February 2011 for scheduled inspections, as early as April 2017.