*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. We are now 
 injecting freshwater by a motor driven pump powered by the off-site 
 transmission line.
 The current rate of water injection is approx. 5 m3/h.
-As it is suspected that hydrogen gas is accumulated inside Primary 
 Containment Vessel, we commenced the valve opening operation concerning 
 injection of nitrogen gas into the primary containment vessel at 10:30 
 pm 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.
-The current rate of water injection is approx. 5 m3/h through the 
 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 10:10 am on June 1, we changed the rate of water injection to the 
 reactor through reactor feed water system piping arrangement from approx. 
 12.5 m3/h to approx. 11.5 m3/h. 
 The current rate of water injection is approx. 11.5 m3/h through the 
 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 happened. 

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 happened. 

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 happened. 

Operation for cooling the spent fuel pools 
-At 5:21 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 6:11 pm on the same day, the rated flow reached to 
 approx. 100m3/h. Later at 1:47 am on June1, we adjusted the flow rate to 
 80m3/h.
-At 5:06 am on June 1, we stopped primary pumps. From 6:06 am to 6:53 am, 
 we injected fresh water through spent fuel pool cooling and filtering 
 system of Unit 2.
-At 2:34 pm on June 1, we started the water injection to Unit 3 by a 
 temporary motor driven pump (from 2:41 pm, we added hydrazine 
 (antioxidant). 
-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.
 Since May 27, we have started spraying dust inhibitor to Unit 1's turbine 
 building. We will implement spraying the dust inhibitor to other 
 buildings including Unit 1 to 4's turbine buildings as well as reactor 
 buildings one by one.
-Since 10:08 am on April 19, we had been transferring high level 
 radioactive wastewater from the vertical shaft near the turbine building 
 of Unit 2 to the Centralized Radiation Waste Treatment Facility. At 4:01 
 pm on May 26, a transferring operation was stopped.
-At 2:00 pm on May 1, we started transferring the accumulated water in 
 turbine building of Unit 6 to temporary tanks.
-At 11:00 am on May 10, we started transferring the accumulated water 
 from the underground level of reactor building to the radiation waste 
 treatment facility of Unit 6.
-Since 6:04 pm on May 17, we had been transferring high level radioactive 
 waste water from the underground level of the turbine building of Unit 3 
 to the Centralized Radiation Waste Treatment Facility, but the transfer 
 was suspended due to an inspection on transmission lines and buildings 
 at 9:10 am, on May 25.
-At 8:00 am on May 31, 2011, we confirmed oil leakage to the sea around 
 the curtain wall of the water intake canal of Unit 5 and 6, Fukushima 
 Daiichi Nuclear Power Station. As a result of our investigation, we 
 confirmed that oil leaked from pipes around seawall to the port through 
 holes of steel sheet piles and that the leakage already stopped. Since 
 the diffused area was just around the curtain wall and the surface of 
 the sea around Shallow Draft Quay and the oil film was very thin, we 
 confirmed that there is no spread to the outer sea. We completed 
 installing oil-absorbing mat around seawall at approximately 2:00 pm 
 and also installed oil fences at 4:50 pm. We plan to protect pipes 
 around seawall and collect the oil.
-We will continue to take all measures to ensure the safety and to 
 continue monitoring the surrounding environment around the power station.