Hmm. Dont think they really have any options other than restarting them, tough, because Japan has quite uniquely crappy geography (and population density) for renewables. Onshore wind resource is crap, the offshore one would get wrecked by the first tsnuami to come along, regardless of size, and given the insanely high utilization of land in the japanese islands, the only place you could ever put solar cells is on rooftops, which doesnt work out to enough power when so much of your population lives in multistorage housing, geothermal appears to cause earthquakes, so that is just right out. Seriously, if Japan doesnt want to burn fossil, do they really have any alternatives to paying through the nose for the most seismic proof reactors they can design? Alternatives that keep the lights on, mind?