Since the Fukushima nuclear crisis began a year ago, Japan's energy supply mix has undergone a shakeup, with only two out of the nation's 54 commercial nuclear reactors currently online and thermal power filling the gap.

The government is reviewing its overall energy policy, but a panel of experts given the task of drawing up options by this spring is deeply divided over the role nuclear power should play.

While the issue of what energy policy the country should pursue in the long term is still under discussion, Japan is guardedly moving toward the restart of idled reactors.