An aerial view shows Kansai Electric Power Co’s Ohi nuclear power plant’s No. 4 reactor (front) in Ohi, Fukui prefecture, in this file photo taken by Kyodo July 19, 2012. Japan is set to be nuclear power-free, for just the third time in more than four decades, and with no firm date for re-starting an energy source that has provided about 30 percent of electricity to the world’s third-largest economy. Kansai Electric Power Co’s Ohi No.4 reactor is scheduled to be disconnected from the power grid late on September 15, 2013, and then shut for planned maintenance. It is the only one of Japan’s 50 reactors in operation after the nuclear industry came to a virtual halt following the March 2011 Fukushima disaster. REUTERS/Kyodo (JAPAN – Tags: ENERGY BUSINESS) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. IT IS DISTRIBUTED, EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS. MANDATORY CREDIT. NO