The Nuclear Regulation Authority decided Wednesday to allow Japan's only two reactors currently online to continue operating after new safety requirements for nuclear plants are introduced next Monday, as it sees no serious problems with them at the moment.
While all the 50 commercial reactors in Japan will be obliged to meet the new nuclear standards from next week if they want to operate, the Nos. 3 and 4 reactors at Kansai Electric Power Co.'s Oi plant will operate until sometime in September, when they will be taken offline for mandatory routine checks.
In a report that evaluated the current status of the reactors in Fukui Prefecture in light of the new regulations, the NRA said that as of the end of June "We think facilities and the way things are managed will not create serious safety problems immediately."
NRA Chairman Shunichi Tanaka told a meeting with other NRA commissioners that the safety level of the reactors has become higher than before because the plant operator has taken emergency measures based on requests by regulators.
But he added, "I want the operator to make further efforts to improve safety so that the reactors can (fully) satisfy the new regulation standards."
Other NRA members also supported the conclusion of the report, but one of the commissioners, Kayoko Nakamura, criticized it, saying she felt the utility's behavior and awareness of safety issues have "not received a pass mark."
The NRA will determine whether the two reactors can resume operation after the routine checkups are over by assessing more strictly whether they meet the new requirements, including the absence of active faults under the plant.
A team appointed by the NRA has been examining whether such faults exist, but the process has been prolonged as experts are divided on the issue.
Kansai Electric said Monday that the outcome of its latest trench survey did not change its view that a fault called F-6, which is believed to run under an emergency water intake channel for the Nos. 3 and 4 reactors, is not active.
The utility is expected to report the findings to the NRA around mid-July. If the F-6 fault has the potential to move in the future, it will be difficult to resume the two reactors' operations as construction of important facilities on active faults is not allowed in quake-prone Japan.
Some people living near the plant welcomed the latest decision reached by the NRA, with a 40-year-old man of Oi town's association of commerce and industry saying that keeping the reactors running is "good for the local economy."
A 69-year-old opponent living in the same town, however, said that safety appears to be taking a backseat in the NRA's assessment, asking "Why does the NRA allow the reactors to remain online when a conclusion has not been reached on the issue of active faults?"
After the 2011 disaster at Tokyo Electric Power Co.'s Fukushima Daiichi complex heightened concerns over the use of nuclear power, reactors in Japan were unable to restart following routine maintenance, leaving the country with no nuclear power generation since May last year.
The No. 3 and 4 reactors at the Oi plant on the Sea of Japan coast, however, were reactivated in July the same year because they cleared provisional safety standards created by the government at that time. Since then, they have remained the sole operating reactors in the country.
If the two go offline in September this year, Japan is likely to enter another period with no nuclear power generation, because no other reactors are likely to restart by then.
Operators of other reactors are expected to start applying for their restarts once the new regulations come into force next Monday, but an assessment to check whether they satisfy the new requirements may take around six months.
The new regulations, which are aimed at preventing recurrences of disasters like the one at the Fukushima plant, require utilities to take specific measures to protect their nuclear plants from tsunami and to prevent and minimize the consequences of severe accidents.