*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 0:30 pm to 4:44 pm, April 23rd, we conducted water spray to Unit 4  
  by the concrete pumping vehicle. 
- We will conduct further water spray depending on the conditions of 
  spent fuel pools, if needed. 

Others 
- At 10:08 am on April 19th we started transferring high level radioactive
  wastewater to the Centralized Radiation Waste Treatment Facility.
- From 11:30am to 2:00pm, we opened and closed the double doors and 
  conducted surveys of the situation of the inside of the nuclear reactor 
  building of Unit 3 and measured a dose of radiation, etc. by a remote 
  control robot. Also, from 4:00pm to 5:30pm, we did the same kind of work
  on Unit 1. From 1:42pm to 2:33pm on April 18th, we opened and closed the
  double doors, measured a dose of radiation and so on, and conducted 
  surveys of the situation of the inside of the nuclear reactor building 
  of Unit 2, by a remote control robot.
- We will continue to take all measures to ensure the safety and to 
  continue monitoring the surrounding environment around the power station.