*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 nuclear 
  reactor through the feed water system was initiated.
- From 3:37 pm on March 25, we started injecting freshwater and are now 
  injecting fresh water by a motor driven pump powered by the off-site 
  transmission line.
- 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 7.
- At 10:01 am on May 6th, in order to make nuclear reactor flooded to the 
  top of Fuel range, we have increased the amount of injecting freshwater 
  from approximately 6 m3/h to approximately 8 m3/h.

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.

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 4:53 pm on May 12, as a part of work to switch the water injection 
  line to the nuclear reactor from the fire extinction system to the 
  reactor feed water system, we started water injection through the reactor 
  feed water system in addition to through the fire extinction system.

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 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 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 reactor cold shutdown. 
- 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 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 reactor cold shutdown. 
- At this moment, we do not consider any reactor coolant leakage inside 
  the reactor happened.

Operation for cooling the spent fuel pools 
- We will continuously conduct further water spray depending on the 
  conditions of spent fuel pools, if needed.

Others 
- At 1:30 on April 26th, we have started spraying the dust inhibitor 
  inside the building.
- At 9:01am on May 10th, we temporarily suspended the transfer of high 
  level radioactive wastewater from the vertical shaft near the turbine 
  building of Unit 2 to the Centralized Radiation Waste Treatment Facility, 
  in order to lay out pipes from the turbine building of Unit 3. At 3:20 
  pm on May 12th, since part of its laying out pipes operation, which 
  affect to workers in exposed dose is finished we restarted the transfer. 
- At 2:00pm on May 1st, we have started transferring the accumulated water 
  in turbine building of Unit 6 to temporary tanks.
- At 11:00am on May 10th, we have started transferring the accumulated 
  groundwater inside the reactor building to the radiation waste treatment 
  facility in Unit 6.
- We will continue to take all measures to ensure the safety and to 
  continue monitoring the surrounding environment around the power station.