The crisis at the Fukushima No. 1 nuclear plant has heightened concern in the Kansai region, where 15 atomic reactors are located less than 55 km from Japan's largest freshwater lake, a source of water for millions of people in Kyoto and Osaka.
The fears and questions being raised about the effects of a nuclear accident at one of the Fukui Prefecture plants has spurred local governors to review their disaster plans.
All of Kansai's nuclear power is generated by reactors on the Sea of Japan coast in Fukui.