S101022 Status of Damage for Thermal Power Plants in The Great East Japan Earthquake - Part 2 : Outline of Status of Restoration

Abstract

The devastating earthquake of Mw9.0 hit the Tohoku district, north-east part of Japan on March 11, 2011. About 16,000 people died and 3,000 people were missing by the strong motion and tsunami, and the economic damage was estimated about 16.9 trillion yen except for the influence by the nuclear accident of Fukushima Danchi Nuclear Power Plant. The industrial facilities, power plants, or research facilities were damaged in this earthquake, and various kinds of mechanical equipment set in these facilities were also damaged. The Thermal and Nuclear Power Engineering Society had set up the investigation committee and investigated the seismic damage of mechanical equipment of these industrial facilities for the purpose to understand the situation and cause of the damages in such facilities and contribute to improvement of preparedness for the forthcoming earthquake. The main damages of thermal power plants due to the Great East Japan Earthquake on March 11, 2011 were caused by surging giant tsunami after the mam shock, rather than earthquake vibration The tsunami washed out vehicles, tanks and utility-facilities, which were placed in the power plants. Machinery equipment installed on the lower floor of turbine building and lower part of boiler was respectively fatally damaged, and electric facilities such as panel boards and motors caused insulation fault by being emerged in sea water. There were no significant damages for facilities due to liquefactions in case of that foundation piles and ground improvement had already been earned out. Electric power facilities themselves don't have major problems regarding earthquake-resistance strength, but the design considering tsunami should be established in near future