*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.
 Water is currently injected at approx. 4.0m3/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. 2.2m3/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 10:32 am to 0:32 pm, hydrazine was 
 also injected) 
-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. 
-From 11:55 am to 0:41 pm on October 7, 2011, cooling of the reactor by 
 the residual heat removal system (A) was stopped and the pump of residual 
 heat removal sea water system (C) and residual heat removal sea water 
 systems were put under the checkup. Since no defect was confirmed during 
 the checkup, the operation of the residual heat removal system (A) was 
 restarted. 

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. 
-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
-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.
-At 10 am on October 7, we started transferring the accumulated water from
 Turbine Building of Unit 6 to temporary tanks.
-At 2:06 pm on October 7, water spray in the plant site using the treated 
 accumulated water in the unit 5 and 6 in order to prevent the dust 
 scattering and fire outbreak from the cut down trees. It is confirmed by 
 the radioactivity measurement that the water used fro the spray meet the 
 threshold specified in the "guideline regarding radioactive materials in 
 the bathing area".