Japan Nuclear Watchdog Finalizes Safety Requirements for Plant Operators

       By Mari Iwata and Yuko Takeo 

    TOKYO--Japan's Nuclear Regulation Authority said Wednesday that it has finalized the country's new safety guidelines for nuclear power plants that reflect the lessons learned from the March 2011 Fukushima disaster.

    But the watchdog said that any restart of the country's currently idled reactors will likely take months.

    The new guidelines will come into effect on July 8, after which time the authority will start accepting applications from power companies for restarts of the units.

    "We've reached a major turning point," Shunichi Tanaka, chairman of the authority, said at the meeting of the authority that took place Wednesday.

    Finalizing the guidelines has just created a framework for safety checks to take place, and it will take a long time to approve restarts, Kayoko Nakamura, one of the authority's five board members said.

    The government of Prime Minister Shinzo Abe is keen to restart many of the nation's nuclear power plants, reversing a plan to phase out nuclear power by the previous government in charge at the time of the disaster.

    The Abe administration's stance, driven in part by a desire to reduce the heavy cost of imported fossil fuels for conventional power plants, comes despite widespread opposition among the public to nuclear power. In a recent poll conducted by the Kyodo News, 52% of respondents said they were opposed to operating nuclear power plants due to safety concerns while 30% were supportive.

    Currently, 48 of the country's 50 reactors are offline, while the two working reactors will be suspended in September for compulsory maintenance that occurs once every 13 months.

    The new, stricter regulations call for nuclear power plant operators to make sure that all of their reactors are able to withstand even highly unlikely natural disasters and accidents such as powerful earthquakes or airplane crashes.

    The guidelines also require plant operators to build seawalls that can endure large tsunamis, secondary control rooms that can manage the cooling down of nuclear reactors from a distance and stricter measures against fires, including the installation of fire-resistant cables。

    The new guidelines also provide more flexibility depending on the type of reactor used. For pressurized water reactors, used mainly in western Japan, there will be a five-year grace period for some safety equipment such as filters for venting systems. Such plants are considered less likely to suffer from the pressure build-up that afflicted the Fukushima Daiichi plants, forcing the venting of highly contaminated steam.

    Such PWR reactors are used by Kansai Electric Power Co. (9503.TO), Kyushu Electric Power Co. (9508.TO), Shikoku Electric Power Co. (9507.TO) and Hokkaido Electric Power Co. (9509.TO).

    In March 2011, an unexpectedly high tsunami generated by a strong earthquake knocked out all of the backup power at the Fukushima Daiichi nuclear power plant, led the plant to meltdowns by paralyzing cooling systems. Since the aftermath, power utilities across the country kept their reactors idle after regular maintenance to dissuade public fears.

    Write to Mari Iwata at mari.iwata@wsj.com and Yuko Takeo at yuko.takeo@dowjones.com