A nuclear reactor at a power plant in central Japan would be temporarily shut down Saturday night because of a problem with its emergency cooling system, news reports said.
The shutdown would put further strain on Japan's power supply after the March 11 earthquake and tsunami damaged and halted electricity production at a six-reactor power plant in Fukushima prefecture and caused other reactors to be shut down for inspection, leaving 19 of the country's 54 reactors running, DPA reported.
Kansai Electric Power Co said it would shut down one of the four reactors at its Ohi Nuclear Power Station in Fukui prefecture in the central part of Honshu island to discover what caused the pressure to drop in a tank that can inject water into the reactor in emergencies.
The drop in pressure occurred Friday night but returned to normal about an hour later, Kansai Electric said.
There were no radioactive leaks and no danger to the public, the government's Nuclear and Industrial Safety Agency said.
About one-third of Japan's electricity is produced by reactors, but the accident at the Fukushima Daiichi Nuclear Power Station, which has leaked radioactive substances into the environment since the March disaster, has caused anti-nuclear sentiment to rise.
Prime Minister Naoto Kan, who once called for Japan to step up its nuclear power generation, said Wednesday that the country should phase out nuclear power and instead promote renewable energy in the wake of the world's worst nuclear disaster in 25 years.