Japan govt bears most blame for Fukushima: ex-PM

Japan's prime minister at the time of the Fukushima nuclear crisis apologised today and said the government and its push for nuclear energy bore most of the responsibility for the disaster.

"The nuclear accident was caused by a nuclear plant which operated as national policy," Naoto Kan told a parliamentary inquiry into the cause of the worst nuclear accident since Chernobyl in 1986.

"I believe the biggest portion of blame lies with the state," said the former premier, who has come out strongly against nuclear power since the Fukushima disaster in March last year.

"As the person who was in charge of the country at the time of the accident, I sincerely apologise for my failure to stop it," said Kan, who stepped down in September after 15 months in office.

Kan came in for intense criticism for creating a distraction when he visited the Fukushima Daiichi nuclear plant on March 12, 2011 - a day after it was swamped by a huge tsunami - as emergency workers were grappling with what would become full-blown meltdowns.

His administration was also lambasted for providing too little information to the public as reactors went into meltdown, apparently withholding computer models that showed how radiation from the venting reactors might spread.

Tens of thousands of people were later evacuated from an area around the plant after it began spewing radiation. Many have still not been allowed home, with some areas expected to be uninhabitable for decades.

Tokyo Electric Power (TEPCO), the operator of the plant, was seen as confused and slow to release information in a response widely thought to have been inept.

TEPCO, one of the world's largest utilities, whose tentacles of influence reach well inside Japan's huge government bureaucracy, has also been criticised for ignoring warnings about the potential dangers from quake-generated tsunamis.

At the hearing today, Kan attacked TEPCO for its failure to keep the government informed about the accident.

"I was thinking it was a battle against an invisible enemy. I thought, if the situation called for it, we might have to risk lives to contain it," he told the hearing.

Kan's public testimony came after a private panel probing the accident said in February the former premier's aggressive involvement had averted a worse crisis.

That panel said it was Kan who ordered TEPCO, which refused to co-operate with the study, to keep men on site.

Experts concluded that if the premier had not stuck to his guns, Fukushima would have spiralled further out of control, with catastrophic consequences.

Kan's then-top government spokesman, Yukio Edano, testified yesterday.