The Nuclear Regulation Authority formally kicked off the process Friday for determining whether the No. 3 and No. 4 reactors at the Oi power plant in Fukui Prefecture, the nation’s only operating reactors, are safe enough to stay online after new safety requirements take effect in July.
The NRA compiled the new regulations to improve safety following the 2011 Fukushima crisis.
Operators of reactors that are still offline will have to wait for the requirements to come into force before applying to restart them.
If the NRA decides the two Oi reactors present no serious safety risks, they will be allowed to run through September, when they are due for routine checkups. The plant is managed by Kansai Electric Power Co.
A panel joined by regulators and Kansai Electric officials held its first meeting Friday to discuss the issue. It plans to compile its assessment in the latter half of June and report the outcome to a meeting of all five NRA commissioners.
At the initial meeting, Kansai Electric explained that it will be ready to bring the two reactors in line with the new requirements by the end of June. These include establishing an emergency command center for each plant.
Kansai Electric said it will use a meeting room next to the No. 3 and 4 reactor control room and other facilities for that purpose until a seismic-isolated building is completed in 2015.
A separate team appointed by the NRA is looking into whether any active faults are under the Oi plant, but experts are divided.
More geological faults under the Kashiwazaki-Kariwa nuclear power plant in Niigata Prefecture may be given active status, according to a survey by manager Tokyo Electric Power Co.
Faults below reactors 3, 5, 6 and 7 are now suspected of having moved between about 200,000 and 400,000 years ago, Tepco said Thursday.
Traces of fault activity 200,000 years ago or later have already been found under units 1 and 2.
The facility, which can generate more electricity than any other nuclear plant in the world, has seven reactors.
An active fault is generally defined as a fault with traces of activity 120,000 to 130,000 years ago or later.
Under new standards, the Nuclear Regulation Authority plans to demand checks on whether faults moved within the past 400,000 years.