*Updates are underlined 

All 6 units of Fukushima Daiichi Nuclear Power Station have been shut down. 

Unit 1 (Shut down) - Explosive sound and white smoke were confirmed after the big quake
  occurred at 3:36 pm on March 12th. It was assumed to be hydrogen
  explosion.
- At approximately 2:30 am on March 23rd, seawater injection to the
  nuclear reactor through the feed water system was initiated.
- From 3:37 pm on March 25th, we started injecting freshwater and are now
  injecting fresh water by a motor driven pump powered by the off-site
  transmission line.
- As it is suspected that hydrogen gas is accumulated inside reactor
  containment vessel, we commenced the valve opening operation concerning
  injection of nitrogen gas into the reactor container vessel at 10:30 pm
  April 6th and commenced injection at 1:31am April 7th. 

Unit 2 (Shut down)  
- At approximately 6:00 am on March 15th, an abnormal noise began
  emanating from nearby Pressure Suppression Chamber and the pressure
  within the chamber decreased. 
- From 10:10 am on March 26th, we started injecting freshwater to the
  reactor and are now injecting fresh water by a motor driven pump powered
  by the off-site transmission line. 

Unit 3 (Shut down)  
- Explosive sound and white smoke were confirmed at approximately 11:01am
  on March 14th. It was assumed to be hydrogen explosion.
- From 6:02 pm on March 25th, we started injecting fresh water to the
  reactor and are now injecting fresh water by a motor driven pump powered
  by the off-site transmission line. 

Unit 4 (outage due to regular inspection)  
- At approximately 6:00 am on March 15th, we confirmed the explosive sound
  and the sustained damage around the 5th floor rooftop area of the
  Nuclear Reactor Building.
- At this moment, we do not consider any reactor coolant leakage inside
  the reactor happened. 

Unit 5 (outage due to regular inspection)  
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 5:00 am on March 19th, we started the Residual Heat Removal System
  Pump (C) in order to cool the spent fuel pool.
- At 2:30 pm on March 20th, the reactor achieved reactor cold shutdown. 
- At this moment, we do not consider any reactor coolant leakage inside
  the reactor happened. 

Unit 6 (outage due to regular inspection)  
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 10:14 pm on March 19th, we started the Residual Heat Removal System
  Pump (B) of Unit 6 in order to cool the spent fuel pool.
- At 7:27 pm on March 20th, the reactor achieved reactor cold shutdown.  
- At this moment, we do not consider any reactor coolant leakage inside
  the reactor happened. 

Operation for cooling the spent fuel pools  
- From 6:15 pm on April 25 to 12:26 am on April 26, water was sprayed to
  the spent fuel pool of Unit 4 by the concrete pumping vehicle.
- We will conduct further water spray depending on the conditions of spent
  fuel pools, if needed. 

Others  
- From 2:44 pm to 5:38 pm on April 25, temporary power panel (6.9kV)
  became temporarily offline due to the reinforcement work of power supply
  line (connecting high voltage power panels in Unit 1/2 and Unit 5/6)
- At 10:08 am on April 19th we started transferring high level radioactive
  wastewater to the Centralized Radiation Waste Treatment Facility.
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power
  station.