This report reflects an effort to assess the status of seismic risk implications on the nuclear plants providing energy in Japan. In this regard, existing and projected plants along with their power capacity have been identified and cataloged. Further, historical data of seismic events deemed significant for the functionality and safety of the plants are included in terms of the Richter magnitude. Also, documents describing standard procedures for aseismic design of power plants have been perused. The coping of the Japanese industry with the major seismic event of Kobe (January 17, 1995) has been considered. It is believed that the procedures followed in designing and operating nuclear power plants reflect sound engineering practices. Barring an extraordinary seismic event, it is expected that the nuclear plants based energy supply in Japan can be maintained with manageable disruptions. Nevertheless, it is recommended that more focused studies regarding individual plants, especially the older ones, be undertaken in the future, regarding the probability of ‘incapacitating’ seismic events. In this manner, a reasonable, reliable model can be calibrated providing the expected percentage of nuclear power loss in Japan, in any given time period. In view of Japan’s stated policy of heavy reliance on nuclear energy, it is nonetheless prudent to plan for aseismic events that could significantly reduce its electricity generating capacity. Such a shortfall would have substantial impacts on world energy markets, on Japan’s ability to provide clean energy in line with its commitments in the Kyoto Protocols, and on Japan’s economic growth. Under standard growth scenarios, we estimate that seismic events that prevent planned new capacity from being brought on line would reduce growth in total factor productivity by about ½ percent per year. This would dampen Japanese energy demand to a level of 2400 (1013 Btu) instead of a level of 2488.5 (1013 Btu) that we forecast in 2010. The impact on economic growth is due to the increase in CO2 emissions caused by substitute energy sources, particularly imported oil. Such increases would need to be moderated by modifying the aggregate production process, and such a change has implications for technical and efficiency change and thus for growth in total factor productivity.