*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.
- 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 9:28 am on October 6, we arranged the amount of water injected to the
  reactor to 3.8 m3/h since we found the reduction in the amount of
  injected water. Water is currently injected at approx. 3.8m3/h through
  reactor feed water system piping arrangement. 
- We commenced injection of nitrogen gas into Primary Containment Vessel
  at 1:31 am on April 7.
- At 11:22 am on August 10, we started cyclic cooling for the water in the
  spent fuel pool by an alternative cooling equipment of the 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 fresh water by a motor driven pump powered
  by the off-site transmission line. 
- At 2:59 pm on September 14, we started injecting water to the reactor
  through core spray system water injection piping arrangement in addition
  to the water injection through reactor feed water system piping
  arrangement.
  Water is currently injected at approx. 3.7 m3/h through reactor feed
  water system piping arrangement, and at approx. 7.1m3/h through core
  spray system water injection piping arrangement.
- From 5:21 pm on May 31, we started cyclic cooling for the water in the
  spent fuel pool by an alternative cooling equipment of the Fuel Pool
  Cooling and Filtering System. 
- 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 11:01 am
  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 2:58 pm on September 1, we started water injection by core spray
  system in addition to water injection by the reactor feed water system
  piping arrangement. 
  Water is currently injected at approx. 2.3m3/h through reactor feed
  water system piping arrangement, and at approx. 8.1m3/h through core
  spray system water injection piping arrangement.
- From 7:47 pm on June 30, we started cyclic cooling for the water in the
  spent fuel pool by an alternative cooling equipment of the Fuel Pool
  Cooling and Filtering 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 around 6 am on March 15, we confirmed the explosive sound and the
  sustained damage around the 5th floor rooftop area of Reactor Building.
- From 12:44 pm on July 31, we started cyclic cooling for the water in the
  spent fuel pool by an alternative cooling equipment of the Fuel Pool
  Cooling and Filtering System. 
- From 11:34 am on August 20, we started an operation of desalination
  equipment in the spent fuel pool.
- 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 2:33 pm on September 15, we started separately cooling the reactor
  through the Residual Heat Removal System and the spent fuel pool through
  Equipment Cooling Water System and Fuel Pool Cooling System.
- At this time, we don't think there is any reactor coolant leakage inside
  the primary containment vessel. 

Others 
- At around 10 am on June 13, we started the operation of the circulating
  seawater purification facility installed at the screen area of Unit 2
  and 3.
- At 8 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
  cesium adsorption instrument No.2. 
- From 9:51 am on September 13 to 1:16 pm on October 4, we transferred
  accumulated water from the turbine building of Unit 2 to High
  Temperature Incinerator Building of Centralized Radiation Waste
  Treatment Facility. 
  At 1:48 pm October 6, we started to transfer accumulated water from the 
  basement of underground floor in turbine building of Unit 2 to High 
  Temperature Incinerator Building of Centralized Radiation Waste 
  Treatment Facility by using newly installed pump.  
- At 10 am on September 30, we started transferring the accumulated water
  from Turbine Building of Unit 3 to High Temperature Incinerator Building
  of Centralized Radiation Waste Treatment Facility.
- From 10 am to 4pm on October 5, we transferred the accumulated water
  from Turbine Building of Unit 6 to the temporary tanks. 
- At 9:58 am on October 6, we stopped the operation of Water Desalinations
  No2 and No3 because we found stain of leaked water in the water joint at
  the outlet piping of the Water Desalinations' waste RO supply pump. We 
  fixed the outlet piping and at 1:01 pm on October 6, and we restarted 
  the operation of the Water Desalinations(reverse osmosis membrane) No2 
  and No3.