Tokyo Electric Power's quake-hit nuclear power plant in northwest Japan could take longer than a year to resume operations if defects are found in key safety devices, media quoted an expert set to head an investigation team as saying.
"At least one year is needed for operations to resume," Haruki Madarame, a University of Tokyo professor specialising in nuclear engineering, was quoted by Kyodo news agency as saying on Wednesday night.
The Nikkei business daily quoted Madarame as saying it was impossible to resume operations of all seven reactors at TEPCO's Kashiwazaki-Kariwa nuclear power station in Niigata Prefecture within "a year or two".
A TEPCO spokesman said he was unaware of Madarame's remarks. "We are trying to restart the plant as soon as possible," he said.
Fears about the safety of Japan's nuclear industry have been revived by leaks of water with low-level radiation from the plant in the city of Kashiwazaki after it was hit by a 6.8 magnitude quake on July 16.
The facility -- the world's largest nuclear power plant -- was shut down automatically in the quake and will remain closed indefinitely for safety checks.
A crane in a building that houses one of the reactors was badly damaged by the quake, making it hard to carry out safety checks and inspections, TEPCO officials said. The nuclear plant was designed to generate more than 3% of Japan's power.
TEPCO has said it will buy power and work existing thermal and nuclear plants harder to meet peak electricity demand during summer.