The Japanese government approved new safety guidelines for nuclear power plants on Friday in a bid to restart reactors idled after the Fukushima disaster last year.

The move comes as the government gears up to decide whether two reactors in western Japan should be restarted. Only one of the country's 54 reactors remains in operation, raising the possibility of power shortages.

The guidelines, approved by Prime Minister Yoshihiko Noda, include measures to prevent a nuclear accident even if reactors are hit by natural disasters as severe as those that ravaged the Fukushima Daiichi plant.

Japan's formerly-trusted nuclear power industry lost public confidence when the earthquake and tsunami of March last year knocked out cooling systems at Fukushima, sending three reactors into meltdown.

Tens of thousands of people were forced from their homes and vast swathes of farmland were contaminated in the world's worst nuclear accident for a quarter of a century.

The new safety standards are said to be more extensive than the two-stage stress test mandated for nuclear power plants in the wake of the Fukushima crisis.

The reactors must clear at least the first-stage test before they can resume operations.

Industry minister Yukio Edano said the government is expected to take a decision next week on whether to restart two idled reactors at the Oi nuclear plant operated by Kansai Electric Power.

"We have yet to reach a conclusion," the minister said.

The government's nuclear safety regulators recently said the two reactors cleared the first-stage, despite strong public mistrust.

In late March, Tokyo Electric Power, which operates the Fukushima plant, shut down a reactor for scheduled safety checks, leaving all its 17 reactors offline including three units that suffered a meltdown.

Only one of Japan's 54 units -- in northernmost Hokkaido -- is still working, and that is scheduled to be shut down for maintenance work in May.