TOKYO, July 3 (Kyodo) — The Nuclear Regulation Authority decided Wednesday to allow Japan's only two reactors currently online to continue operating even after new safety requirements for atomic plants are introduced next Monday, as it sees no serious problems with them at the moment.
The Nos. 3 and 4 reactors at the Oi plant in Fukui Prefecture will operate through September, when they will be taken offline for mandatory routine checks. After that, Japan is likely to enter a period with no nuclear power generation for the second time following the 2011 Fukushima Daiichi complex disaster.
Operators of other reactors are expected to start applying for their restarts once the new regulations come into force, 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 atomic plants from tsunami and to prevent and minimize the consequences of severe accidents.
In a report that evaluated the current status of Kansai Electric Power Co.'s Oi reactors, the NRA said, "As of the end of June, we think...the situation will not create serious safety problems immediately."
It will be determined whether the two reactors can resume operations following the routine checkups, after the NRA assesses 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 have been 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.
After the 2011 Fukushima disaster heightened concerns over the use of nuclear power, reactors were unable to restart following routine maintenance, leaving Japan with no atomic power generation from May last year.
The No. 3 and 4 reactors at the Oi plant, 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.