*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. 
-We commenced injection of nitrogen gas into Primary Containment Vessel at 
 1:31am on April 7. 
-At 9:00 am on August 10, we started to assemble steel frame for the 
 Reactor Building Cover. 
-At 11:22 pm 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 the reactor feed water system piping 
 arrangement. Water is currently injected at approx. 3.8 m3/h through 
 reactor feed water system piping arrangement, while the water injection 
 through the core spray system water injection piping arrangement is under 
 adjustment. 
-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 11:01am 
 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. 4 m3/h through 
 reactor feed water system piping arrangement, and at approx. 3 m3/h 
 through core spray system. 
-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 approximately 6 am on March 15, we confirmed the explosive sound and 
 the sustained damage around the 5th floor rooftop area of Reactor 
 Building. 
-From 0:44 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 3:12 pm on September 10, we started cooling the spent fuel pool 
 through the Residual Heat Removal System A using the seawater pump C. We 
 will conduct cooling the reactor and the spent fuel pool by turn through 
 the System A. 
-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 8:00 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 10:00 am on September 11, we started transferring accumulated water 
 from the turbine building of Unit 3 to the High Temperature Incinerator 
 Building of Centralized Radiation Waste Treatment Facility. 
-At 9:51 am on September 13, we started transferring accumulated water 
 from the turbine building of Unit 2 to High Temperature Incinerator 
 Building of Centralized Radiation Waste Treatment Facility. 
-At 3:58 am on September 13, in order to maintain the water treatment 
 facility, we stopped the cesium absorption instrument and the 
 decontamination instrument. 
-At 9:53 am on September 14, we started transferring accumulated water at 
 Unit 1 condenser to the basement of Unit 1 turbine building. 
-At 11:8 am on September 14, we stopped the operation of cooling 
 facilities of common pool because the common pool power center will be 
 moved with the replace of power panel located at the basement of the 
 spent fuel common pool's building. 
-At approx. 12:40 pm on September 14, 6 partner company's workers, who 
 maintained water treatment faculties, conducted contamination check of 
 full-face masks when they returned from the work site to 1F's Main 
 Anti-Earthquake Building. As a result, inner side of the filter for 4 out 
 of the 6 workers were confirmed to be contaminated. We will confirm 
 whether the 6 workers might have absorbed contaminated materials inside 
 of their bodies using whole body counter.