*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 12th. It was assumed to be hydrogen 
 explosion. 
-At approximately 2:30 am on March 23rd, seawater injection to the nuclear 
 reactor through the feed water system was initiated. 
-From 3:37 pm on March 25th, we started injecting freshwater. 
-As it is suspected that hydrogen gas is accumulated inside reactor 
 containment vessel, we commenced the valve opening operation concerning 
 injection of nitrogen gas into the reactor container vessel at 10:30 pm 
 April 6th and commenced injection at 1:31am April 7th. 
 
Unit 2 (Shut down) 
-At approximately 6:00 am on March 15th, an abnormal noise began emanating 
 from nearby Pressure Suppression Chamber and the pressure within the 
 chamber decreased. 
-From 10:10 am on March 26th, 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. 
-From 7:35 pm on April 12th, we started transferring the high level 
 radioactive accumulated water in the trench of the turbine building to 
 the condenser by an underwater pump. At 5:04pm on April 13th, the 
 scheduled transfer was completed. 
 
Unit 3 (Shut down) 
-Explosive sound and white smoke were confirmed at approximately 11:01am 
 on March 14th. It was assumed to be hydrogen explosion. 
-From 6:02 pm on March 25th, 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. 
 
Unit 4 (outage due to regular inspection) 
-At approximately 6:00 am on March 15th, we confirmed the explosive sound 
 and the sustained damage around the 5th floor rooftop area of the Nuclear 
 Reactor Building. 
-At this moment, we do not consider any reactor coolant leakage inside the 
 reactor happened. 
 
Unit 5 (outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained. 
-At 5:00 am on March 19th, we started the Residual Heat Removal System 
 Pump (C) in order to cool the spent fuel pool. 
-At 2:30 pm on March 20th, the reactor achieved reactor cold shutdown. At 
 around 5:24 pm on March 23rd, when we switched the temporary Residual 
 Heat Removal System Seawater Pump, it has stopped automatically. At 
 around 4:14 pm on March 24th we replaced the pump, and restarted cooling 
 of reactor at around 4:35 pm. 
-At this moment, we do not consider any reactor coolant leakage inside the 
 reactor happened. 
 
Unit 6 (outage due to regular inspection) 
-Sufficient level of reactor coolant to ensure safety is maintained. 
-At 10:14 pm on March 19th, 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 20th, the reactor achieved reactor cold shutdown. 
-In relation to the two seawater side pumps of the Residual Heat Removal 
 System, we switched the power source from temporary to permanent at 3:38 
 pm and 3:42 pm, Mar 25 respectively. 
-At this moment, we do not consider any reactor coolant leakage inside the 
 reactor happened. 
 
Operation for cooling the spent fuel pools 
-We will conduct further water spray depending on the conditions of spent 
 fuel pools, if needed. 
 
Others 
-We measured radioactive materials (iodine etc.) inside of the nuclear 
 power station area (outdoor) by monitoring car and confirmed that 
 radioactive materials level is getting higher than ordinary level. As 
 listed below, we have determined that specific incidents stipulated in 
 article 15, clause 1 of Act on Special Measures Concerning Nuclear 
 Emergency Preparedness (Abnormal increase in radiation dose measured at 
 site boundary) have occurred. 
  · Determined at 4:17 pm Mar 12th (Around Monitoring Post 4 ) 
  · Determined at 8:56 am Mar 13th (Around Monitoring Post 4 ) 
  · Determined at 2:15 pm Mar 13th (Around Monitoring Post 4 ) 
  · Determined at 3:50 am Mar 14th (Around Monitoring Post 6 ) 
  · Determined at 4:15 am Mar 14th (Around Monitoring Post 2 ) 
  · Determined at 9:27 am Mar 14th (Around Monitoring Post 3 ) 
  · Determined at 9:37 pm Mar 14th (Around main entrance ) 
  · Determined at 6:51 am Mar 15th (Around main entrance ) 
  · Determined at 8:11 am Mar 15th (Around main entrance ) 
  · Determined at 4:17 pm Mar 15th (Around main entrance ) 
  · Determined at 11:05 pm Mar 15th (Around main entrance ) 
  · Determined at 8:58 am Mar 19th (Around MP5) 
 Hereafter, if the measured figure fluctuates and goes above and below 
 500 micro Sv/h, we deem that as the continuous same event and will not 
 regard that as a new specific incidents stipulated in article 15, clause 
 1 of the Act on Special Measures Concerning Nuclear Emergency 
 Preparedness (Abnormal increase in radiation dose measured at site 
 boundary) has occurred. In the interim, if we measure a manifestly 
 abnormal figure and it is evident that the event is not the continuous 
 same event, we will determine and notify. 
-The national government has instructed evacuation for those local 
 residents within 20km radius of the periphery and evacuation to inside 
 for those residents from 20km to 30km radius of the periphery, because 
 it is possible that radioactive materials are discharged. 
-From April 2nd, we began to transfer the radioactive water we collected 
 from the Central Environmental Facility to the Unit 4 turbine building. 
 On April 4th, water level of the pit in the trench of Unit 3 increased 
 by 15cm from previous day. Pathway of water flow is unknown. We can not 
 deny the possibility that water in the turbine building of Unit 4 flows 
 into the trench of Unit 3. So, we stopped transferring water to the Unit 
 4 turbine building to make assurance. Present water level of the pit in 
 the trench of Unit 3 is not changed from the time we stopped 
 transferring, and is being stable. 
-From 7:03 pm on April 4th, we started to discharge to the sea 
 approximately ten thousand tons of the accumulated low level radioactive 
 water in the Central Radioactive Waste Disposal Facility. We are 
 confirming the amount of discharged water. From 9:00 pm on April 4, we 
 conducted discharging a total of 1,500 tons of the low level radioactive 
 subsurface water stored in the sub drain pits of Unit 5 and 6. The amount 
 of discharged water was approximately 1,323 tons. 
-From 3:00 pm to 4:30 pm, April 5th, in order to prevent diffusion of 
 radioactive contaminated water out from the site port facility to 
 breakwater area which is south to the power station, we began repair of 
 breakwater by founding the large sandbag around it to replace damaged 
 steel water bar. We will continue the operation to prevent diffusion. 
 From 8:45 am to 10:45 am on April 11, in order to prevent water 
 containing radioactive material from spilling from a plant's port to the 
 sea, we conducted works to install 120m wide double silt fences around a 
 breakwater on the south of the station. From 8:45 am to 1:50 pm on April 
 13, we installed silt fences (double layered) in front of Unit 3 and 4 
 screens, and from 7:45 am to 0:20 pm on April 14 we also installed the 
 same in front of Unit 1 and 2 screens, and around the north of south 
 breakwater. 
-We took a sample from Unit 4 spent fuel pool on 12th April, in order to 
 understand the fuel condition stored within the spent fuel pool. We are 
 planning to conduct a nuclide analysis. 
-From 8:02 to 9:55 am on April 15th, an unmanned helicopter was flown over 
 Unit 1 to 4, in order to check the condition of the reactor buildings. 
-We will continue to take all measures to ensure the safety and to 
 continue monitoring the surrounding environment around the Power Station.