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. 
- 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. 
  Water is currently injected at approx. 3.6 m3/h through reactor feed water 
  system piping arrangement. 
- We commenced injection of nitrogen gas into Primary Containment Vessel 
  at 1:31am on April 7. 
- At 9:00 am on August 10, we started to assemble steel frame for the 
  Reactor Building Cover. 
 
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 fresh water by a motor driven pump powered 
  by the off-site transmission line. 
  Water is currently injected at approx. 3.5 m3/h through reactor feed water 
  system piping arrangement. 
- At 8:06 pm on June 28, we started injecting nitrogen gas into the 
  Primary Containment Vessel. 
 
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. 
- From 2:09pm to 2:58pm on September 1, we adjusted the water flow into 
  the reactor and started water injection by core spray system in addition 
  to water injection by the reactor feed water system piping arrangement. 
  At 2:43 pm on September 5, we adjusted the rate of water injection through 
  reactor feed water system piping arrangement to approx. 6 m3/h. 
  Water is currently injected at approx. 6 m3/h through reactor feed water 
  system piping arrangement, and at approx. 3 m3/h through core spray system. 
- At 8:01 pm on July 14, injection of nitrogen gas into the Primary 
  Containment Vessel started. 
 
Unit 4 (Outage due to regular inspection) 
- At approximately 6 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 don't think there is any reactor coolant leakage 
  inside the primary containment vessel. 
 
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 
  in order to cool the spent fuel pool. 
- At 2:30 pm on March 20, the reactor achieved cold shutdown. 
- At 2:45 pm on July 15, we started the operation of the original Residual 
  Heat Removal System (System B) by its original seawater pump. 
- At this time, we don't think there is any reactor coolant leakage inside 
  the primary containment vessel. 
 
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 of Unit 6 to cool down Spent Fuel Pool. 
- At 7:27 pm on March 20, the reactor achieved cold shutdown. 
- At this time, we don't think there is any reactor coolant leakage inside 
  the primary containment vessel. 
 
Operation for cooling the Spent Fuel Pools 
- At 5:21 pm on May 31, we started cyclic cooling of Spent Fuel Pool of 
  Unit 2 by using alternative cooling system of the Pool's cooling and 
  filtering system. 
- At 7:47 pm on June 30, we started cyclic cooling of Spent Fuel Pool of 
  Unit 3 by using alternative cooling system of the Pool's cooling and 
  filtering system. 
- At 12:44 pm on July 31, we started cyclic cooling of Spent Fuel Pool of 
  Unit 4 by using alternative cooling system of the Pool's cooling and 
  filtering system. 
- At 11:22 am on Aug 10, we started cyclic cooling of Spent Fuel Pool of 
  Unit 1 by using alternative cooling system of the Pool's cooling and 
  filtering system. 
 
Others 
- At around 10 am on June 13, we started the operation of the circulating 
  seawater purification facility installed at the screen area of Units 2 
  and 3. 
- At 8:00 pm on June 17, we started operation of Water Treatment Facility 
  against the accumulated water. At 6:00 pm on July 2, we started the 
  circulating injection cooling to inject the water, which was treated by 
  the accumulated water treatment system, to the reactors through the 
  buffer tank. 
- At 7:41 pm on August 19, we started treatment of accumulated water by 
  parallel operation of one line from the cesium adsorption instrument to 
  the decontamination instrument and the other treatment line of the 2nd 
  cesium adsorption instrument. 
- At 11:34 am on August 20, we started operation of the desalting facility 
  for the spent fuel pool of Unit 4 
- At 9:39 am on August 30, we started transferring accumulated water from 
  the turbine building of Unit 2 to Process Building of Centralized 
  Radiation Waste Treatment Facility. 
- At 9:54 am on August 30, we started transferring accumulated water from 
  the turbine building of Unit 3 to High Temperature Incinerator Building 
  of Centralized Radiation Waste Treatment Facility. 
- At 5:51 am on September 6, the decontamination instruments of Waste 
  Treatment Facility stopped with an alarm indicating a mixer trouble* of 
  High Speed Coagulation Settling Facility. We reset and restarted the 
  instruments. However, the same alarm and serious fault alarm went off at 
  6:21 am, and the decontamination instruments and cesium adsorption 
  instruments stopped. 
- From 10:11 am to 2:54 pm on September 6, we transferred accumulated 
  water in turbine building of Unit 2 from the condenser to the basement. 
 
* In the previous announcement of plant status as of 10 am this was
described as power supply trouble, but we have corrected it into mixer
trouble.