*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 12. It was assumed to be hydrogen explosion.
- At approximately 2:30 am on March 23, seawater injection to the reactor
  through the reactor feed water system was initiated.
- From 3:37 pm on March 25, we started injecting freshwater by a motor
  driven pump powered by the off-site transmission line. We are now
  injecting freshwater by a motor driven pump powered by the off-site
  transmission line.
  The current rate of water injection is approx. 5 m3/h through reactor
  feed water system piping arrangement.
- As it was suspected that hydrogen gas had been accumulated inside 
  Primary Containment Vessel, we commenced the valve opening operation
  concerning injection of nitrogen gas into the primary containment vessel
  at 10:30 pm on April 6 and commenced injection at 1:31am April 7.
 
Unit 2 (Shut down) 
- At approximately 6:00 am on March 15, an abnormal noise began emanating
  from nearby Pressure Suppression Chamber and the pressure within the
  chamber decreased. 
- From 10:10 am on March 26, we started injecting freshwater to the
  reactor and are now injecting freshwater by a motor driven pump powered
  by the off-site transmission line. 
  The current rate of water injection is approx. 5 m3/h through the
  reactor feed water system piping arrangement.
 
Unit 3 (Shut down) 
- Explosive sound and white smoke were confirmed at approximately 11:01am
  on March 14. It was assumed to be hydrogen explosion.
- From 6:02 pm on March 25, 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.
  The current rate of water injection is approx. 11.5 m3/h through the
  reactor feed water system piping arrangement.
 
Unit 4 (Outage due to regular inspection) 
- At approximately 6:00 am on March 15, we confirmed the explosive sound
  and the sustained damage around the 5th floor rooftop area of Reactor
  Building.
- At this moment, we do not consider any reactor coolant leakage inside
  the primary containment vessel has occurred.
 
Unit 5 (Outage due to regular inspection) 
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 5:00 am on March 19, we started the Residual Heat Removal System Pump
  (C) in order to cool the spent fuel pool.
- At 2:30 pm on March 20, the reactor achieved cold shutdown. 
- At this moment, we do not consider any reactor coolant leakage inside
  the primary containment vessel has occurred.
 
Unit 6 (Outage due to regular inspection) 
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 10:14 pm on March 19, 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 20, the reactor achieved cold shutdown. 
- At this moment, we do not consider any reactor coolant leakage inside
  the primary containment vessel has occurred.
 
Operation for cooling the spent fuel pools 
- At 5:21 pm on May 31, we started cyclic cooling of the spent fuel pool
  in Unit 2 using alternative cooling system for fuel pool cooling and
  filtering system. 
- We will continuously conduct further water spray depending on the
  conditions of spent fuel pools, if needed.
 
Others 
- At 1:30 pm on April 26, we started spraying the dust inhibitor inside
  the site. On May 27, we started spraying dust inhibitor to Turbine
  Building of Units 1. We will implement spraying the dust inhibitor to
  other turbine and reactor buildings of Units 1 to 4.
- At 2:00 pm on May 1, we started transferring accumulated water in the
  turbine building of Unit 6 to temporary tanks.
- At 11:00 am on May 10, we started transferring accumulated water from
  the underground level of reactor building to the radiation waste
  treatment facility of Unit 6.
- At 6:39 pm on June 4, we started transferring accumulated water from
  vertical shafts (trenches) of turbine building of Unit 2 to Process Main
  Building.
- At 12:42 pm on June 11, we started to operate local exhausters in order
  to improve inside environment of Unit 2 Reactor Building.
- At 3:30 pm on June 11, we started transferring accumulated water from 
  the basement of Unit 3 Turbine Building to Centralized Radiation Waste 
  Treatment Facility (Process Main Building). 
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power station.