*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.
-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 
 is currently injected at approx. 3.5㎥/h through reactor feed water 
 system piping arrangement.
-As it was suspected that hydrogen gas had been accumulated inside Primary 
 Containment Vessel, in order to prevent increase in density of oxygen, we 
 commenced the valve opening operation concerning injection of nitrogen 
 gas into the primary containment vessel at 10:30 pm on April 6 and 
 commenced injection at 1:31am 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 freshwater by a motor driven pump powered by the 
 off-site transmission line. 
 At 6:27 pm on June 23, we changed the water injection line so that we can 
 inject water to Unit 1 and 2 by the motor driven pump for Unit 1 and 
 stopped the motor driven pump for Unit 2. 
 Water is currently injected at approx. 3.5㎥/h through reactor feed water 
 system piping arrangement. 

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 ㎥/h through reactor feed water 
 system piping arrangement. 

Unit 4 (Outage due to regular inspection) 
-At approximately 6:00 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 do not consider any reactor coolant leakage inside the 
 primary containment vessel has occurred. 

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 
 (C) in order to cool the spent fuel pool.
-At 2:30 pm on March 20, the reactor achieved cold shutdown. 
-At this moment, we do not consider any reactor coolant leakage inside the 
 primary containment vessel has occurred. 

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 
 (B) of Unit 6 in order to cool the spent fuel pool.
-At 7:27 pm on March 20, the reactor achieved cold shutdown. 
-At this moment, we do not consider any reactor coolant leakage inside the 
 primary containment vessel has occurred. 

Operation for cooling the spent fuel pools 
-At 5:21 pm on May 31, we started cyclic cooling of the spent fuel pool 
 in Unit 2 using alternative cooling system for fuel pool cooling and 
 filtering system. 
-At 4:35 pm on June 24, we started the cooling of the spent fuel pool by 
 the pump of the Fuel Pool Cooling and Filtering System.
-From 3:00 pm to 5:18 pm on June 27, we injected boric acid solution to 
 Spent Fuel Pool of Unit 3.
-We will continuously conduct further water spray depending on the 
 conditions of spent fuel pools, if needed. 

Others 
-At 1:30 pm on April 26, we started spraying the dust inhibitor inside 
 the site. 
-At 11:00 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 approximately 10:00 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 4:20 pm on June 27, the operation of circulation injection cooling 
 was initiated by injecting water from the filter water tank as well as 
 usage of the treated water regarding water injection to the reactor. At 
 5:55 pm, since we confirmed a leakage from the pipe which supplies water 
 from treated water tank to injection pump of reactor, we stopped 
 supplying treated water. Injecting water to the reactor has been kept 
 from filtered water tank at stated flow rate. 
-From 8:00 pm on June17, we started operation of water treatment of 
 accumulated water at accumulated water treatment facility. 
-From 3:32 pm on June 21 to 9:58 am on 9:58, we had transferred 
 accumulated water in turbine building of Unit 3 to central waste 
 treatment facility building.
-At 9:56 am on June 22, we started transferring accumulated water in 
 turbine building of Unit 2 to central waste treatment facility building.
-At 9:40 am on June 28, we started injecting fresh water to the reactor 
 well (unit 4) and temporally dry separation pool for environment 
 improvement (reduce radio active dose) on 5th floor reactor building of 
 unit 4. 
-We will continue to take all measures to ensure the safety and to 
 continue monitoring the surrounding environment around the power station.