20 Avril 2016
April 18, 2016 (Mainichi Japan)
TOKYO (Kyodo) -- The chairman of the Nuclear Regulation Authority said Monday the safety watchdog has no plan to halt operating nuclear reactors in southwestern Japan despite concerns about a recent wave of earthquakes hitting the neighboring region, as there have been no signs of safety problems at the facility.
"We will not make such a judgment (to halt the reactors) unless there is a scientifically convincing basis," Shunichi Tanaka said about the Sendai nuclear complex in Kagoshima Prefecture, at a press conference after a special meeting of the NRA earlier in the day.
The NRA held the meeting after a string of earthquakes on the southwestern Japan island of Kyushu killed more than 40 people and injured over 1,000 people since the first major quake with a magnitude of 6.5 hit Kumamoto Prefecture in central Kyushu on Thursday night.
The nuclear watchdog confirmed at the meeting there are no abnormalities at four nuclear power plants located relatively near the quake-stricken area, including the two reactors at the Sendai facility operated by Kyushu Electric Power Co., the only two commercial power reactors currently operating in Japan.
The other three nuclear facilities are the Genkai plant in Saga Prefecture, the Ikata complex in Ehime Prefecture and the Shimane facility in Shimane Prefecture, run by Kyushu Electric, Shikoku Electric Power Co. and Chugoku Electric Power Co., respectively. They are all offline with their spent fuel rods stored in pools.
The levels of earthquake acceleration recorded at the four plants were all below those that trigger automatic shutdowns, with the biggest acceleration of 20.3 gals registered at the Genkai nuclear power station in northwestern Kyushu, according to the NRA.
One gal equals a change in the rate of motion of 1 centimeter per second squared. The Fukushima Daiichi nuclear power plant was hit by a jolt of 675 gals when an earthquake and tsunami triggered meltdowns at the complex in 2011.
Tanaka added that the regulator will continue to closely monitor the situation as earthquakes continue to rock the Kyushu area.
The NRA approved the restart of Sendai's two reactors in 2014 after safety measures were implemented that assume a magnitude-8.1 quake could occur on the fault zone which moved to cause a magnitude-7.3 quake early Saturday.
The nuclear watchdog said that the potential impact of jolts caused by that fault zone on the safety of the Sendai plant is limited as the complex is located about 90 kilometers from the fault zone.
The government also has no intention of stopping the two Sendai reactors, with Chief Cabinet Secretary Yoshihide Suga saying that there is no reason to halt them.
Shikoku Electric aims to restart in late July a reactor at the Ikata complex in Ehime on Shikoku Island, and about 170 km east of Kumamoto. The Shimane plant on Honshu, Japan's most heavily populated island, is located about 360 km northeast of Kumamoto.