TOKYO (Reuters) - The late manager of Japan's destroyed Fukushima plant questioned the safety of large nuclear facilities, documents showed on Thursday, potentially affecting the debate over the restart of the world's biggest nuclear power station.
The late Masao Yoshida, who led the emergency response at Tokyo Electric Power Co's Fukushima Daiichi plant after the March 2011 nuclear disaster, told investigators five months later that facilities with six or seven reactors were difficult to operate and had inherent safety risks, according to transcripts released by the government.
His comments have implications for the debate over the world's biggest power station, Kashiwazaki Kariwa, Tepco's only hope of reviving idled reactors as it faces a decades-long cleanup of Fukushima.
They also come a day after the Nuclear Regulation Authority said Kyushu Electric Power Co's Sendai plant in southwestern Japan had met safety requirements needed to restart, the first step to reopening the industry.
"When you're talking about demerits, most other plants have four (reactors) at one site. I've always disliked dense location (of nuclear reactors)," Yoshida told investigators.
Yoshida cited Kashiwazaki Kariwa, a seven-reactor site in northern Japan also run by Tepco. The utility has struggled to win local support to restart that plant while it embarks on the decades-long shutdown of the Fukushima facility and faces the almost-certain closure of its nearby sister plant.
Yoshida, who died of cancer last year, was seen as a national hero for his decisive action and lack of regard for his personal safety after a massive earthquake and tsunami set off nuclear meltdowns at Fukushima.
The interview was contained in a release of hundreds of pages in transcripts of interviews, including with then-Prime Minister Naoto Kan, conducted in an investigation of the handling of the disaster.
The government has been under pressure to release the transcripts after the Asahi newspaper in May published a series of stories based on a leaked copy of Yoshida's testimony.
The newspaper retracted a key claim on Thursday - that workers at Fukushima Daiichi had fled the plant despite an order from Yoshida to stay.
Yoshida said there had been "chaos" at the Kashiwazaki Kariwa site after a previous earthquake in northern Japan and added that grouping numerous nuclear reactors together made it far more difficult to operate.
"I thought it wasn't very good from a risk-diversification standpoint, but (Tepco) had already built this (Fukushima Daiichi) and Kashiwazaki, so I had to work within that (system)," he said.
(Reporting by Mari Saito and Kentaro Hamada; Additional reporting by Kiyoshi Takenaka; Editing by Nick Macfie)