Japanese governor Tokihiro Nakamura believes nuclear power is vital for the resource-poor land, but even he says the central government must put safety pledges in writing before he'll agree to restart off-line reactors -- a sign of the tough battle ahead to repair tattered public trust after the Fukushima crisis.

The myth that nuclear power was cheap, clean and safe was shattered when a March quake and tsunami triggered the world's worst nuclear crisis in 25 years at Tokyo Electric Power Co's Fukushima plant, spewing radiation and forcing mass evacuations.