* Updates from previous press release 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.4.6 m3/h and that from the core spray system is approx.1.8 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. 
   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.5.9 m3/h. 
 - With regard to the water injection volume for Unit 2 reactor, which was 
   increased with temperature figure raising, we have gradually adjusted it 
   to the original volume before temperature increasing (Feed water system: 
   approx. 3.0m3/h, core spray system: approx. 6.0m3/h). During our 
   observing the plant parameter after decreasing the flow rate of feed 
   water system on February 22, we found that one thermometer in the lower 
   part of the RPV (top of the lower head 135°) indicated the different 
   movement from Others. From 12:21 pm to 2:48 pm on February 23, we 
   investigated the concerned device. As the result of the measurement of 
   DC resistance, we found no breaking wire and availability of the 
   thermometer. But we confirmed that the DC resistance of it became higher 
   than the previous measurement test data. We will evaluate the soundness 
   of the concerned device and examine correspondence in future. We make 
   sure no re-criticality state because there were no significant changes 
   at the monitoring post and as the result of the sampling for the Gas 
   Control System of the Unit 2; we confirmed that the concentration of 
   Xe-135 was below the detectible limit. 
    · At 5:00 am on February 29, the temperature of the lower part of the 
      RPV (top of the lower head 135°) : approximate 44.6 °C 
    (Reference) 
    · At 5:00 am on February 29, the temperature of the lower part of the 
      RPV (top of the lower head 270°) : approximate 40.9 °C 
 - 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 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. 
 
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.1.7 m3/h and that from the core spray system is approx.5.1 m3/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. 
 - As installation works of the PCV gas control system was completed, we 
   started a test operation at 11:38 am on February 23, 2012. We confirmed 
   that an exhaust flow amount was stable at 33Nm3/h at 2:10 pm and started 
   an adjustment operation. 
 - 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. 
 
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. 
 
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. 
 - 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 1:56 pm on February 28, we started transfer the accumulated water 
   from the basement of turbine building of Unit 3 to Miscellaneous Solid 
   Waste Volume Reduction Treatment Building (High Temperature Incinerator 
   Building). 
 - At 2:00 pm on February 28, we started transferring accumulated water 
   from basement of unit 2 turbine building to Centralized Radiation Waste 
   Treatment Facility Process Main building. 
 - At 10:00 am to 4:00 pm on February 28, we transferred the accumulated 
   water from the basement of T/B, Unit 6 to the temporary tank. At 10:00 
   am on February 29, we restarted the transfer. 
 - As we confirmed that high radioactivity contaminated water is 
   accumulating in the pit of water circulating pump discharge valve of 
   unit 3 pump chamber at the inspection of trench etc. conducted on 
   January 19, 2012, from 8:51 am to 3:45 pm on February 28, 2012 we 
   transferred accumulated water from the pit to the basement of unit 2 
   turbine building. At 8:17 am on February 29, we restarted the transfer. 
 - At 8:37 am on February 29, the gradual decrease in the volume of treated 
   water was confirmed in the second cesium adsorption apparatus. In order 
   to conduct a backwashing of the filter, we suspended the apparatus.