*The 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, 2011. It was assumed to be hydrogen 
 explosion. 
-At 3:37 pm on March 25, 2011, 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 10:11 am on December 10, 2011, in addition to water injection from 
 water feeding system, we started water injection from piping of core 
 spray system to the reactor. 
 At 5:26 pm on January 15, 2011, the decrease of injection water flow to 
 Reactor was found so that water injection from Core Spray System was 
 adjusted from approx. 1.8 ㎥/h to 2.0 ㎥/h (water injection from feed 
 water system was remained unchanged as approx. 4.5 ㎥/h). 
 Current water injection volume is approx. 4.5 ㎥/h from the reactor feed 
 water system and approx. 2 ㎥/h from the core spray system. 
-At 1:31 am on April 7, 2011, we commenced injection of nitrogen gas into 
 Primary Containment Vessel. 
-At 11:22 am on August 10, 2011, 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. 
-On October 28, 2011, we completed installation of the cover for the 
 Reactor Building in order to contain dispersion of radioactive substances. 
-At 4:04 pm on November 30, 2011, we started operation to inject nitrogen 
 into the reactor pressure vessel. 
-At 6:00 pm on December 19, 2011, a full-scale operation of the PCV gas 
 management system started. 

Unit 2 (Shut down) 
-At approximately 6:00 am on March 15, 2011, an abnormal noise began 
 emanating from nearby Pressure Suppression Chamber and the pressure 
 within the chamber decreased. 
-At 10:10 am on March 26, 2011, 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, 2011, in addition to water injection from 
 water feeding system, we started water injection from piping of core 
 spray system to the reactor. 
 Current water injection volume is approx. 2.8 ㎥/h from the reactor feed 
 water system and approx. 7 ㎥/h from the core spray system. 
-At 5:21 pm on May 31, 2011, 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, 2011, we started injecting nitrogen gas into the 
 Primary Containment Vessel. 
-At 6:00 pm on October 28, 2011, a full-scale operation of the PCV gas 
 management system started. 
-At 10:46 am on December 1, 2011, we started the nitrogen injection to the 
 Reactor Pressure Vessel. 

Unit 3 (Shut down) 
-Explosive sound and white smoke were confirmed at approximately 11:01 am 
 on March 14, 2011. It was assumed to be hydrogen explosion. 
-At 6:02 pm on March 25, 2011, 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 2:58 pm on September 1, 2011, we started water injection by core spray 
 system in addition to water injection by the reactor feed water system 
 piping arrangement. 
 Current water injection volume is approx 2 ㎥/h from the reactor feed 
 water system and approx. 7.1 ㎥/h from the core spray system. 
-At 7:47 pm on June 30, 2011, 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, 2011, injection of nitrogen gas into the Primary 
 Containment Vessel started. 
-At 4:26 pm on November 30, 2011, we started operation to inject nitrogen 
 into the reactor pressure vessel. 
-At 3:18 pm on January 14, we started operation of the radioactive 
 material removal instrument for the spent fuel pool in Unit 3 

Unit 4 (Outage due to regular inspection) 
-At around 6 am on March 15, 2011, we confirmed the explosive sound and 
 the sustained damage around the 5th floor rooftop area of Reactor 
 Building. 
-At 12:44 pm on July 31, 2011, 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 1:30 pm to 3:14 pm on January 12, 2012, 
 we injected hydrazine [corrosion inhibitor] in conjunction with the 
 cyclic cooling). 
-At 10:58 am on November 29, 2011, in order to decrease more salinity, we 
 installed Ion exchange equipment and started the operation of such 
 equipment. 
-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, 2011, we started the Residual Heat Removal System 
 Pump in order to cool the spent fuel pool. 
-At 2:45 pm on July 15, 2011, we started the operation of the original 
 Residual Heat Removal System (System B) by its original seawater pump. 
-At 10:11 am on December 22, 2011, since we finished the recovery work of 
 seawater pump (System B) of equipment water cooling system, we made a 
 trial run. At 11:25 am on the same day, we confirmed no abnormalities and  
 restarted the operation. 
-At this moment, 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, 2011, we started the Residual Heat Removal 
 System Pump of Unit 6 to cool down Spent Fuel Pool. 
-At 2:33 pm on September 15, 2011, 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 moment, we do not think there is any reactor coolant leakage  
 inside PCV. 

Others 
-At around 10:00 am on June 13, 2011, we started the operation of the 
 circulating seawater purification facility installed at the screen area 
 of Unit 2 and 3. 
-At 8:00 pm on June 17, 2011, 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, 2011, 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 2:06 pm on October 7, 2011, we started to spray purified accumulated 
 water brought from Unit 5 and 6 continually in order to prevent dust 
 scattering and potential fire outbreaks from the cut down trees.
-On October 28, 2011, we started installation of the water proof wall at 
 the sea side, in front of the existing shore protection, Units 1-4, in 
 order to contain marine pollution by underground water.
-At 12:25 pm on December 13, 2011, we started the re-circulating operation 
 of desalination facility (reverse osmosis membrane type) for the purpose 
 of suppression of condensed water after desalination treatment. 
-Because of the finding of accumulated water containing radioactive 
 materials at the trench between the Process Main Building and the 
 Miscellaneous Solid Waste Volume Reduction Treatment Building[High 
 Temperature Incinerator Building](December 18, 2011), we started the 
 inspection of other trenches at the site on January 11. 
-At 2:48 pm on January 15, we started to transfer accumulated water from 
 the ground floor of the turbine building of Unit 3 to the Centralized 
 Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume 
 Reduction Treatment Building [High Temperature Incinerator Building] and 
 the Process Main Building). 
-At 2:57 pm on January 15, we started to transfer accumulated water from 
 the ground floor of the turbine building of Unit 2 to the Centralized 
 Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume 
 Reduction Treatment Building [High Temperature Incinerator Building] and 
 the Process Main Building). 
-At 9:13 am on January 16, 2011, we suspended the second cesium absorption 
 apparatus due to reverse cleaning of the filters because the amount of 
 disposal water of the second cesium absorption apparatus decreased 
 gradually. 
-At 10:00 am on January 16, 2011, we started the transferring of 
 accumulated water at the underground of Unit 6 turbine building to 
 temporary tank.