*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 which is now powered by the off-site transmission line. At
  10:02 am on June 22, we changed the rate of water injection to the
  reactor from approx. 4.0 m3/h to approx. 3.5m3/h through reactor feed
  water system piping arrangement. Water is currently injected at approx.
  3.5m3/h through reactor feed water system piping arrangement.
- As it was suspected that hydrogen gas had been accumulated inside
  Primary Containment Vessel, in order to prevent increase in density of
  oxygen, 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. 
  At 6:27 pm on June 23, we changed the water injection line so that we
  can inject water to Unit 1 and 2 by the motor driven pump for Unit 1 and
  stopped the motor driven pump for Unit 2. 
  Water is currently injected at approx. 3.5m3/h through 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.
  Water is currently injected at approx. 9 m3/h through 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. 
- At 4:35 pm on June 24, We started the cooling of the spent fuel pool by
  the pump of the Fuel Pool Cooling and Filtering System.
- From 9:56 am to 11:23 am on June 26, we injected boric acid to the spent 
  fuel pool of Unit 3. 
- 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. 
- 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 approximately 10:00 am on June 13, we started the operation of the
  circulating seawater purification facility installed at the screen area
  of Unit 2 and 3.
- From 8:00 pm on June17, we started operation of water treatment of
  accumulated water at accumulated water treatment facility. At 10:00 am
  on June 25, we stopped operation of the facility in order to conduct
  flashing of the facility and resumed operation at 3:00 pm. At 3:24 pm,
  the facility automatically stopped caused by the annunciator "water
  level low". We restarted the facility but again, at 4:10 pm, it
  automatically stopped caused by the same annunciator. We presumed that
  this was caused by malfunction of the water level gauge, decided not to
  use this water level gauge and use the other water level gauge operating
  normally and resumed operation at 4:35 pm. 
- At 3:32 pm on June 21, we started transferring accumulated water in
  turbine building of Unit 3 to central waste treatment facility building.
- At 9:56 am on June 22, we started transferring accumulated water in
  turbine building of Unit 2 to central waste treatment facility building.
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power station.