The nuclear meltdown could have been avoided in the case that adequate precaution of such severe natural disasters had been established. TEPCO had never improved the design of four reactors at Fukushima Daiichi, which were still employing old design by General Electric Company. Based on an investigation report by Japanese legislatives, other five reactors buildings with enhanced and more spacious design, which were proclaimed to be secure against tsunami of height up to 45-foot, were not attacked down. However, the deficient former design of reactor buildings could not accommodate the generators inside. It turned out that the emergency generators were then placed in the turbine buildings which had lower grade of safety requirements [4]. Another
