2014 Volume 14 Pages 6-23
TThis article considers why the Fukushima Daiichi No.1-4 plants reached to the severe accident by comparing with other plants where were also attacked by big tsunami, such as the Tōkyō Electric Power Company(TEPCO)’s No.5-6 plants and the Fukushima Daini, the Tōhoku Electric Power Company’s Onagawa and the Japan Atomic Power Company’s Tōkai Daini. It examined some nuclear accident investigation reports and verified the hypothesis that as a primary factor, the TEPCO had been a trial calculation of over ten meters height of tsunami before 3.11 but did not take the effective anti-tsunami measures for a management reason and as a secondary factor, the Nuclear Safety Commission and the Nuclear and Industrial Safety Agency were captured by electric power companies and could not regulate them effectively, then the Fukushima Daiichi No.1-4 plants reached to the severe accident. If the TEPCO took some cheap and effective anti-tsunami measures such as sealing water of or raising up switchboards, the Fukushima Daiichi No.1-4 plants might not have reached to the severe accident and if the regulatory authorities realized independence, professionalism and transparency from electric power companies, they might have regulated to make the TEPCO taken those anti-tsunami measures effectively.
