ENSI Report on Fukushima I: Event sequences – ENSI-AN-7999

Immediately after the first live images of the accident in the Fukushima Dai-ichi nuclear power plant were broadcast all over the world on 11 March 2011, the Swiss Federal Nuclear Safety Inspectorate (ENSI) convened a group of internal experts comprising engineers, geophysicists, nuclear physicists and psychologists. A state of emergency was declared for Fukushima Dai-ichi at 15:42 hours on 11 March 2011. The earthquake and the consequent tsunamis led to a total power failure as well as severe destruction and impairment of important safety-related plant components such as the secondary auxiliary nuclear cooling water and the emergency diesel generators. Damage at the Dai-ni power plant site, located about twelve kilometres further south, was far less.