*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. At 
 10:02 am on June 22, we changed the rate of water injection to the 
 reactor from approx. 4.0 m3/h to approx. 3.5m3/h through reactor feed 
 water system piping arrangement. Water is currently injected at approx. 
 3.5m3/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.
 From 11:55 am to 6:05 pm on June 21, we temporarily stopped operating the
 nitrogen supply equipment to Unit 1 Primary Containment Vessel due to
 work of power supply for alternative cooling equipment of Unit 1 spent
 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 freshwater by a motor driven pump powered by the
 off-site transmission line. 
 At 10:04 am on June 22, we changed the rate of water injection to the 
 reactor from approx. 4.5 m3/h to approx. 4.5m3/h through reactor feed 
 water system piping arrangement. Water is currently injected at approx. 
 4.0m3/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.
 At 10:06 am on June 21 we changed the rate of water injection to Unit 3
 Reactor from approx. 11 m3/h to approx. 10m3/h through reactor feed water
 system piping arrangement. Water is currently injected at approx. 10 m3/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 2:31 pm on June 22, water injection to Unit 4 through temporary 
 spraying equipment was initiated. 
-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 2:00 pm on May 1, we started transferring accumulated water in the
 turbine building of Unit 6 to temporary tanks.
-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.
-From 2:20 pm on June17 to 5:09 pm on June 21, we transferred accumulated
 water in the vertical shaft (trench) of the turbine building of Unit 2 to
 the condenser in the turbine building of Unit 1. (From 2:59 pm on June 17
 to 1:37 pm on June 20, we stopped the operation of the transfer pump due
 to the transfer pump did not properly work.)
-From 8:00 pm on June17, we started operation of water treatment of
 accumulated water at accumulated water treatment facility. At 12:54 am on
 June18, we stopped operation of the facility temporarily due to the
 radiation dose at surface level measured up to the basis of exchange
 filter of Cesium adsorption Instruments.
-At 3:32 pm on June 21, we started transferring 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. 
-From 8:23 am to 2:31 pm on June 22, we injected fresh water to reactor
 well and dry separator pit of Unit 4 for the purpose of environmental
 improvement (decreasing dose) at 5th floor of 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.