![]() Tohoku Electric also took a different approach to emergency response-one that was more organized, collaborative, and controlled than Tepco’s. Tepco’s tsunami risk characterization and assessment was, in the judgment of one the world’s renowned tsunami experts, Costas Synolakis, director of the Tsunami Research Center at the University of Southern California, a “cascade of stupid errors that led to the disaster.”Įmergency response. According to the NAIIC report, Tepco “resorted to delaying tactics, such as presenting alternative scientific studies and lobbying.” While Tohoku Electric learned from past earthquakes and tsunamis-including one in Chile on February 28, 2010-and continuously improved its countermeasures, Tepco overlooked these warnings. According to the National Diet of Japan’s Fukushima Nuclear Accident Independent Investigation Commission (NAIIC), the initial construction was based on existing seismological information, but later research showed that tsunami levels had been underestimated. Tepco, on the other hand, to make it easier to transport equipment and to save construction costs, in 1967 removed 25 meters from the 35-meter natural seawall of the Daiichi plant site and built the reactor buildings at a much lower elevation of 10 meters. As more research was done, the estimated tsunami levels climbed higher, and Tohoku Electric conducted periodic checkups based on the new estimates. Based on that, the company constructed its plant at 14.7 meters above sea level, almost five times that height. The initial predictions showed that tsunamis in the region historically had an average height of about 3 meters. Before beginning construction, Tohoku Electric conducted surveys and simulations aimed at predicting tsunami levels. While the Fukushima Daiichi and Onagawa plants are similar in many ways, the most obvious difference is that Tohoku Electric constructed Onagawa’s reactor buildings at a higher elevation than Tepco’s Fukushima reactor buildings. The difference in outcomes at the two plants reveals the root cause of Fukushima Daiichi’s failures: the utility’s corporate “safety culture.” Furthermore, the tsunami was bigger at Onagawa, reaching a height of 14.3 meters, compared with 13.1 meters at Fukushima Daiichi. Onagawa was only 123 kilometers away from the epicenter-60 kilometers closer than Fukushima Daiichi-and the difference in seismic intensity at the two plants was negligible. The survival of Onagawa, however, suggests otherwise. Most people believe that Fukushima Daiichi’s meltdowns were predominantly due to the earthquake and tsunami. According to a report by the International Atomic Energy Agency mission that visited Onagawa and evaluated its performance, “the plant experienced very high levels of ground motion-the strongest shaking that any nuclear plant has ever experienced from an earthquake,” but it “shut down safely” and was “remarkably undamaged.” Fewer still know how Onagawa managed to avoid disaster. Onagawa managed to remain generally intact, despite its proximity to the epicenter of the enormous earthquake.Įveryone knows the name Fukushima, but few people, even in Japan, are familiar with the Onagawa power station. Fukushima Daini was damaged by the earthquake and tsunami, but the heroic efforts and improvisations of its operators resulted in the cold shutdown of all four operating reactors. The Fukushima Daiichi plant experienced fatal meltdowns and radiation releases. While the three power stations shared similar disaster conditions, nuclear reactor types, dates of operation, and an identical regulatory regime, their fates were very different. Within the affected area were three nuclear power plants: the Fukushima Daiichi and Daini nuclear power plants operated by the Tokyo Electric Power Company (Tepco), and the Onagawa Nuclear Power Station operated by the Tohoku Electric Power Company. On the heels of the destructive magnitude 9.0 earthquake came a tsunami that reached a run-up height of 30 meters in some areas, sweeping entire towns away in seconds. ![]() Three years ago, the biggest recorded earthquake in Japanese history hit Tohoku prefecture, leaving more than 20,000 people dead or missing. ![]() Kiyoshi Kurokawa, “Message from the Chairman,” The Official Report of The Fukushima Nuclear Accident Independent Investigation Commission It was a profoundly manmade disaster-that could and should have been foreseen and prevented.” Although triggered by these cataclysmic events, the subsequent accident at the Fukushima Daiichi Nuclear Power Plant cannot be regarded as a natural disaster. “The earthquake and tsunami of March 11, 2011, were natural disasters of a magnitude that shocked the entire world. ![]()
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