Keywords:Nuclear Accident of Fukushima Daiich, Tohoku Region Pacific Coast Earthquake, Tsunami Height, Flooding
About the cause of Fukushima Daiich nuclear accident, the investigation reports were published by various accident investigation committees which are the government, the national diet, the private sector, TEPCO and academic societies. However, it is the current state that the difference of investigation results between the accident investigation reports and the difference of judgements between the specialists still remain. Our working group has advanced investigation from an academic point of view through the accident investigation reports which mainly compared with four reports, the new evidence and hearing from person concerned. This report shows the investigation results and lessons of our working group through the backgroud and process of the Tsunami height evaluation at before the Fukushima Daiich nuclear accident.