At 2:46PM on March 11th 2011, turbines and reactors of Fukushima Daiichi
Nuclear Power Station Unit 1 (Boiling Water Reactor, rated output 460
Megawatts) and Units 2 and 3 (Boiling Water Reactor, Rated Output 784
Megawatts) that had been operating at rated power automatically shutdown
due to the Tohoku-Chihou-Taiheiyou-Oki Earthquake.
In all 3 Units, one offsite power system out of two was lost and diesel
generators were automatically activated.
At 3:41PM, diesel generators failed and as a result, all the AC power
was lost in Unit 1, 2 and 3. Following this incident, at 3:42PM, it was
determined that a specific incident stipulated in article 15, clause 1
has occurred, and level 1 emergency status was announced, together with
the notification to Ministry of Economy, Technology and Industry,
Governor of Fukushima prefecture, Mayors of Okuma town and Futaba town,
and related institutions in accordance with the law.
Afterwards, in Unit 3, High Pressure Core Injection System has been
automatically shut down. Re-activation of Reactor Core Isolation Cooling
System was attempted but failed, and as we were unable to confirm the
level of water injection to the reactor by the Emergency Core Cooling
System, at 5:10 on March 13th, it was determined that a specific incident
(Emergency Core Cooling System water injection inability) stipulated in
article 15, clause 1 has occurred.