Last year, the Japanese government ordered the nuclear authorities to conduct tests on all Japan's reactors after the 11 March meltdown at Fukushima Daiichi raised questions about the safety of nuclear power, particularly in a country prone to earthquakes and tsunami.

Earlier this week, a team of experts from the International Atomic Energy Agency [IAEA] began a review of the safety tests but said it was up to the Japanese government whether or not to approve the restart of idle reactors.

Currently only three of Japan's 54 reactors – just over 6% of its total nuclear capacity – are in operation after the Fukushima accident forced the closure of active reactors for safety checks.