*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.
  The current water injection amount from the reactor feed water system is 
  approx.4.4 m3/h and that from  the core spray system is approx. 1.9 m3/h.
- 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 
  feed water system, we started water injection from piping of core spray 
  system to the reactor. 
  Because the tendency of temperature rise at the bottom of PCV had been 
  accelerated since February 2, we increased the amount of water injected 
  to the reactor and continued monitoring the tendency of the temperature 
  fluctuation. The temperature remains high around 70.0 °C. On February 6, 
  2012, according to the gas sampling result of Primary Containment Vessel 
  gas control system, the density of Xe-135 was below measurable limit at 
  the outlet of the system, satisfying the criteria to judge the 
  possibility of re-criticality, less than 1Bq/cm3. Therefore we confirm 
  that there is no re-criticality. In order to avoid the increasing 
  possibility of re-criticality to occur, which might be brought up by 
  sudden cold water injection, resulting in the rise of water density 
  inside the reactor, we injected boric acid into the reactor as a safety 
  countermeasures against the re-criticality from 0:19 am to 3:20 am on 
  February 7, which was before increasing the amount of injection water, 
  and changed the amount of the core spray system injection water from 3.7
  m3/h to 6.7m3/h at 4:24 am (the amount of the continuing feed water 
  system injection is 6.8m3/h). Currently, the temperature is approx. 66.0 
  °C (as of 11 am on February 8). We will monitor the progress 
  continuously.
  The current water injection amount from the reactor feed water system is 
  approx. 6.5 m3/h and that from the core spray system is approx. 6.8 m3/h.
- 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 
  control system started. 
- At 10:46 am on December 1, 2011, we started the nitrogen injection to 
  the Reactor Pressure Vessel.
- At 11:50 am on January 19, 2012, we started the operation of the spent 
  fuel pool desalting facility.
- At around 5:00 am on February 8, the alarm of "abnormally low suction 
  pressure of the high pressure RO pump" in the desalination apparatus for 
  the Unit 2 spent fuel pool went off, and the its operation was 
  automatically stopped. The interlock arrangement closed all the 
  isolation valves in the system, and the alternative cooling system for 
  the spent fuel pool continues its operation. Therefore, there is no 
  impact on the cooling. We also confirmed by the site investigation that 
  there was no leakage from the apparatus. 

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.
  The current water injection amount from the reactor feed water system is 
  approx. 2.9 m3/h and that from the core spray system is approx. 6m3/h.
  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.
- 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.
- As 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.
  As a result of the inspection made on February 7, the location where the 
  accumulated water was found and the preliminary results of the nuclide 
  analysis are as follows:
 ·Inside the Unit 5 intake power cable duct
   I-131: below the detectible limit, Cs-134: 1.4 X 10-1 Bq/ cm3, 
   Cs-137: 2.0 X 10-1 Bq/ cm3 
 ·Inside the Unit 5 seawater piping duct
   I-131: below the detectible limit, Cs-134:8.2 X 10-2 Bq/ cm3, 
   Cs-137: 1.1 X 10-1 Bq/ cm3 
 ·Inside the Unit 5 Main transformer cable duct
   I-131: below the detectible limit, Cs-134:7.3 X 10-2 Bq/ cm3, 
   Cs-137: 1.3 X 10-1 Bq/ cm3 
 ·Inside the Unit 5 Booster transformer cable duct
   I-131: below the detectible limit, Cs-134:2.0 X 10-1 Bq/ cm3, 
   Cs-137:2.9 X 10-1 Bq/ cm3 
- At 9:18 am on January 31, we started transfer of Sub-drain Water of Unit 
  6 to the temporary tank. We will conduct transferring to the temporary 
  tank appropriately.
- At 2:14 pm on February 7, 2012, we started transferring the accumulated 
  water from the basement of turbine building of Unit 2 to Centralized 
  Radiation Waste Treatment Facility (Miscellaneous Solid Waste Volume 
  Reduction Treatment Building [High Temperature Incinerator Building]).
- At 10:00 am on February 8, 2012, we started transferring the accumulated 
  water from inside the turbine building of Unit 6 to the temporary tank.
- At approximately 9:40 am on February 8, 2012, workers of the partner 
  company confirmed the water overflow from the temporary water pool 
  located at the east side of Unit 2's turbine building. At the temporary 
  pool of the field site, for the purpose of sub-drain purification test, 
  sub-drain water was pumped up using pumps. Therefore, water overflow has 
  been stopped by the stop of the pumps' operation at around 10:15 am on 
  the same day. Later, as a result of field check, we confirmed that there 
  was no water at the drainage channels around the area. Based on these 
  facts, we concluded that the water did not flow into the drainage 
  channels and did not flow into the sea either. According to the result 
  of the nuclide analysis of water sampled from the tank, the density of 
  Cs-134 was 3.4 X 10-1Bq/cm3 and that of Cs-137 was 5.2 X 10-1Bq/cm3, 
  both of which were equal to the level of the result for the sub-drain 
  water sampled today. Therefore we concluded that the water overflowed 
  was the same water as the sub-drain water. The amount of water 
  overflowed from the tank is currently under estimation.