*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. At 10:02 am on June 21 we changed the rate of water 
  injection to the reactor from approx. 4.5 m3/h to approx. 4.0m3/h 
  through reactor feed water system piping arrangement. Water is currently 
  injected at approx. 4 m3/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.
  From 11:55 am to 6:05 pm on June 21, we temporarily stopped operating the 
  nitrogen supply equipment to Unit 1 Primary Containment Vessel due to 
  work of power supply for alternative cooling equipment of Unit 1 spent 
  fuel pool cooling and filtering system. 

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 10:04 am on June 21 we changed the rate of water injection to Unit 2 
  Reactor from approx. 5 m3/h to approx. 4.5m3/h through reactor feed water 
  system piping arrangement. Water is currently injected at approx. 4.5 
  m3/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.
  At 10:06 am on June 21 we changed the rate of water injection to Unit 3 
  Reactor from approx. 11 m3/h to approx. 10m3/h through reactor feed water 
  system piping arrangement. Water is currently injected at approx. 10 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. 
- 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 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 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 2:20 pm on June17 to 5:09 pm on June 21, we transfered accumulated 
  water in the vertical shaft (trench) of the turbine building of Unit 2 
  to the condenser in the turbine building of Unit 1. (From 2:59 pm on 
  June 17 to 1:37 pm on June 20, we stopped the operation of the transfer 
  pump due to the transfer pump did not properly work.) 
- From 8:00 pm on June17, we started operation of water treatment of 
  accumulated water at accumulated water treatment facility. At 12:54 am 
  on June18, we stopped operation of the facility temporarily due to the 
  radiation dose at surface level measured up to the basis of exchange 
  filter of Cesium adsorption Instruments.
- At 3:32 pm on June 21, we started transferring accumulated water in 
  turbine building of Unit3 to central waste treatment facility building. 
- At 8:23 am on June 22, we started injecting fresh water to reactor well 
  and dry separator pit of Unit 4 for the purpose of environmental 
  improvement (decreasing dose) at 5th floor of reactor building of Unit 4. 
- We will continue to take all measures to ensure the safety and to 
  continue monitoring the surrounding environment around the power station.