One of Japan's two remaining working nuclear reactors was taken offline Tuesday, with the other to be shut down later this month and no restarts in sight amid public hostility to nuclear power.
Kansai Electric Power started reducing generating power at its Unit No. 3 at the Oi plant, Fukui prefecture, western Japan, on Monday afternoon and was fully shut down early on Tuesday, a company official said.
The shutdown was aimed at allowing the operator to be ready for inspections legally mandated within 13 months of the start of commercial operation.
The reactor is one of the only two still generating power in Japan. The other one, Unit No. 4 at Oi, is to be switched off on September 15.
It is not known when they will resume operations because they will be assessed under a set of guidelines recently drawn up by the nuclear watchdog, according to Kansai Electric.
The two reactors were restarted - despite public opposition - in July last year after passing safety tests, ending a brief period in which no atomic power was generated in Japan.
They were the only units to be brought back online after undergoing such tests in the aftermath of the disaster in March 2011 at Fukushima.
There, a 9.0-magnitude earthquake and the tsunami it caused crippled reactor cooling systems, sparking meltdowns and spewing radioactive materials in the world's worst atomic disaster since Chernobyl in 1986.
Japan has turned to pricey fossil-fuel alternatives to fill the gap left by the shutdown of atomic plants, which had supplied about one-third of resource-poor Japan's electricity before the disaster.