Major Events of Fukushima Dai-ichi Nuclear Power Station Unit 1 After Earthquake (1/4/2011 Update)

The massive 9.0-magnitude quake and the tsunami on 11 March have killed more than 11,000 people, with at least 16,700 people still missing across north-eastern Japan along with a massive Nuclear crisis. Major events of Fukushima Dai‐ichi Nuclear Power Station Unit 1 upto today are:

11th 14:46 Under operation, Automatic shutdown by the earthquake

11th 15:42 Report based on the Article 10 (Total loss of A/C power)

11th 16:36 Occurrence of the Article 15 event (Inability of water injection of the Emergency Core Cooling System )

12th 01:20 Occurrence of the Article 15 event (Unusual rise of the pressure in PCV)

12th 10:17 Started to vent.

12th 15:36 Sound of explosion

Reactor-1

12th 20:20 Started to inject seawater and borated water to core.

23rd 02:33 The amount of injected water to the Rector Core was increased utilizing the Feedwater Line in addition to the Fire Extinguish Line. (2m3/h →18m3/h)

23rd 09:00 Switched to the Feedwater Line only.(18m3/h →11m3/h)

Reactor-1

24th 11:30 Lighting in the Central Control Room was recovered.

25th 15:37 Started fresh water injection.

29th 08:32 Switched to the water injection to the core using the temporary motor‐driven pump.

31st 12:00 Started to transfer the stagnant water from the Condensate Storage Tank (CST) to the Surge Tank of Suppression Pool Water (SPT)

31st 13:03 ~16:04 Fresh water spray by Concrete Pump Truck (Fresh water)