*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 m 3/h to approximately 8m3/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. At 4:01 pm on May 13th, we changed water injection amount to
  through the fire extinction system piping arrangement at approximately
  6m3/h and the reactor feed water system piping arrangement at
  approximately 6 m3/h. At 10:01 am on May 14th, we increased water 
  injection to the nuclear reactor of Unit 3 through the fire extinction 
  system piping arrangement from at approximately 6 m3/h to 9 m3/h. (water 
  injection thorough the reactor feed water system piping arrangement is 
  maintained at approximately 6 m3/h).

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 
- From 4:04 pm to 7:04 pm on May 13th, we sprayed water into the spent
  fuel pool of Unit 4 with the concrete pumping vehicle (from 4:20 pm to
  6:41 pm, hydrazine was also injected).
- From 1:00 pm to 2:37 pm on May 14th, we sprayed water into the spent fuel 
  pool of Unit 2 using the temporary motor driven pump. (from 1:08 pm to 
  2:02 pm, hydrazine was also injected).  
- We will continuously conduct further water spray depending on the
  conditions of spent fuel pools, if needed.

Injured etc 
- At about 6:50 AM on May14th, 2011, a worker of a sub-contractor became a
  bad health during a carrying work for drainage treatment system in the
  Centralized Environment Facility. He was carried to hospital.
  Radioactive substances were not attached to the worker.

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.
- From 4:01 am to 5:39 pm, May 13th, we confirmed the plant conditions
  inside of Unit 1's reactor building using the remote-controlled robot.
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power station.