Japan's prime minister has appealed to the nation to accept that two nuclear reactors that remain shut down after the Fukushima disaster must be restarted to protect the economy and livelihoods.

Prime Minister Yasuhiko Noda said the government has taken ample measures to ensure the two reactors in western Japan would be safe from radiation leaks if an earthquake or tsunami as severe as last year's should strike again.

All 50 of Japan's workable reactors are offline for maintenance amid safety concerns since the magnitude 9.0 earthquake and tsunami on March 11, 2011, swept into a coastal plant in Fukushima and sparked the world's second-worst nuclear disaster.

The two reactors at the Ohi nuclear plant are the first two ready to resume generating power, but the public has shown great concern that government failures worsened last year's crisis and may recur.

But Noda said nuclear energy is crucial for Japanese society. The government wants the reactors to be operational to avoid a summer energy crunch.

"We should restart the Ohi No 3 and No 4 reactors in order to protect the people's livelihoods," Noda said.

"The Japanese society cannot survive if we stop all nuclear reactors or keep them halted."

Local consent is not legally required for restarting the reactors, though government ministers have promised to gain understanding from the prefecture.

Noda's speech today was possibly the last obstacle before a resumption of the Ohi reactors.

The Fukui governor made Noda's public appeal conditional to his consent for the startup. With the governor's consent, Noda is expected to make a final go ahead as early as next week, so the restart could take place within days.

The government issued new safety guidelines in April to address residents' worries. In response, Kansai Electric Power Company submitted its safety plans for two reactors at the plant, saying the full upgrades will take up to three years.

He said major cities around the Ohi plant should thank local residents for their burden of supplying electricity to towns around the west despite the safety concerns, apparently seeking to gain their understanding for the resumption.