Quantitative Analysis of Japan’s Energy Security Based on Fuzzy Logic: Impact Assessment of Fukushima Accident

The Fukushima accident of March 2011 had great political, economic, and social impacts on Japan and marked a very important turning point in Japan’s energy policy. As the accident has also greatly exposed the vulnerability of Japan’s energy security, it is crucial to clarify the path that Japan should take to maintain and secure its energy security in case of any possible future outbreak that may threaten its energy security. For this purpose, we conducted a comprehensive and structural analysis of Japan’s energy security based on APERC’s 4As framework and by using fuzzy logic and the Fuzzy-DEMATEL method to quantitatively understand the performance of Japan’s energy security and how the Fukushima accident had impacted the performance. Our results demonstrate that Japan’s energy security has clearly degraded after experiencing Fukushima accident. In addition, the results of the structural analysis by the Fuzzy-DEMATEL method show that the most salient dimension in the 4As framework for improving Japan’s energy security is the “Availability” dimension, and for this purpose nuclear energy and renewables play very important roles in securing the future energy security in Japan; this is consistent with the current energy policy measures announced in the Strategic Energy Plan of 2014.