*New items 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.
-At approximately 2:30 am on March 23, seawater injection to the reactor 
 through the reactor feed water system was initiated.
-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 injection was arranged at approx. 3.9 ㎥/h at 9:02 am on August 5 
 since we observed reduction of the water injection into the reactor. 
 Water is currently injected at approx. 3.9 ㎥/h through reactor feed 
 water system piping arrangement.
-We commenced injection of nitrogen gas into Primary Containment Vessel 
 at 1:31am on April 7. 
 
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.
-Water injection was arranged at approx. 3.9 ㎥/h at 5:50 pm on August 4 
 since we observed reduction of the water injection into the reactor. 
 Water is currently injected at approx. 3.9 ㎥/h through reactor feed 
 water system piping arrangement.
-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.
 Water is currently injected at approx. 9.1 ㎥/h through reactor feed 
 water system piping arrangement.
-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.
-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 am on March 19, we started the Residual Heat Removal System Pump 
 (C) 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 Pump (B).
-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 this time, we don't think there is any reactor coolant leakage inside 
 the primary containment vessel. 
 
Operation for cooling the Spent Fuel Pools 
-At 5:21 pm on May 31, we started cyclic cooling of Spent Fuel Pool of 
 Unit 2 by using alternative cooling system of the Pool's cooling and 
 filtering system.
-At 7:47 pm on June 30, we started cyclic cooling of Spent Fuel Pool of 
 Unit 3 by using alternative cooling system of the Pool's cooling and 
 filtering system.
-At 0:44 am on July 31, we started cyclic cooking of Spent Fuel Pool of 
 Unit 4 by using alternative cooling system of the Pool's cooling and 
 filtering system. 
 
Others 
-At 11 am on May 10, we started transferring accumulated water from the 
 underground level of reactor building to the radiation waste treatment 
 facility of Unit 6.
-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 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.
-From 4:13 pm on July 30 to 7:17 am on August 4, we transferred 
 accumulated water at Unit 3 turbine building to Centralized Radiation 
 Waste Treatment Facility.
-At 7:09 am on August 4, we started transferring accumulated water at Unit 
 2 turbine building to Centralized Radiation Waste Treatment Facility.
-At 8:42 am on August 4, we started transferring accumulated water at Unit 
 3 turbine building to Centralized Radiation Waste Treatment Facility. 
-At 5:32 am on August 4, we stopped Water Treatment Facility to improve 
 the flow rate.
 After the work, we activated the facility at 3:30 pm and restarted 
 operation of the water treatment system at 4:13 pm. When we adjusted the 
 flow rate of the system at 6:55 pm, a pump of the decontamination 
 instruments was stopped and the whole water treatment system was shut 
 down. We confirmed soundness of the pump and reactivated the system at 
 8:30 pm, and operation of the water treatment system was restarted at 
 8:50 pm. 
-At 2:12 am on August 5, a process alarm was activated and the water 
 treatment system was shut down. At 4:03 am, the system was reactivated 
 and the operation was restated at 4:21 am. 
-Around 7 pm on 8:04, we discovered water leakage from a flange of 
 transfer hose of filtered water which is used to clean up salt in a 
 vessel of the cesium adsorption instruments in the site bunker building. 
-At 10:00 am on August 5, we started water transfer of low level 
 radioactive water from the outside temporary tank to the Mega-float.