*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 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 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.
- At 1:28 pm on May 15, we have increased the amount of freshwater
  injected into the reactor from approximately 8m3/h to approximately
  10m3/h so that we can monitor the trend shift of parameters of the
  Reactor Pressure Vessel as well as the primary containment vessel, the
  shift which would be resulted from the increase of the amount of
  injected freshwater. 

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 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. 
- The current rate of water injection is approximately 9m3/h through the
  fire extinction system piping arrangement and approximately 6m3/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 
- From 3:00 pm to 6:32 pm, on May 16, we sprayed water to Unit 3 by a 
  temporary motor driven pump (from 3:10 pm to 5:30 pm, injected hydrazine 
  [corrosion inhibitor] at the same time). 
- 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 10:08 am on April 19, we started transfer of high level radioactive
  wastewater from the vertical shaft near the turbine building of Unit 2
  to the Centralized Radiation Waste Treatment Facility.
- 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
  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.