*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 by a motor
  driven pump which is now powered by the off-site transmission line. 
  Water is currently injected at approx. 3.6m3/h through reactor feed
  water system piping arrangement.
- We commenced injection of nitrogen gas into Primary Containment Vessel
  at 1:31am on 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 fresh water by a motor driven pump powered
  by the off-site transmission line. From 2:25pm on July 17, the motor
  driven pump of Unit 2 is injecting the freshwater to the Unit 1 and 2
  reactors.
  Water is currently injected at approx. 3.4m3/h through reactor feed
  water system piping arrangement. 
- At 9:35 am on July 23, since the volume of injected water into the 
  reactor was found to be decreased, we adjusted the volume up to 3.8m3/h. 
  Hence, water is currently injected at approx. 3.8m3/h through reactor
  feed water system piping arrangement.
- At 8:06 pm on June 28, we started injecting nitrogen gas into the
  Primary Containment Vessel. 

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.
  Water is currently injected at approx. 9.0m3/h through reactor feed
  water system piping arrangement.
- At 8:01 pm on July 14, injection of nitrogen gas into the Primary
  Containment Vessel started. 

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 has occurred. 

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 2:45 pm on July 15, we started the operation of the original Residual
  Heat Removal System Pump (B).
- At this moment, we do not consider any reactor coolant leakage inside
  the primary containment vessel has occurred. 

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 has occurred. 

Operation for cooling the spent fuel pools 
- At 5:21 pm 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 7:47 pm on June 30, we started cyclic cooling of the spent fuel pool
  in Unit 3 using alternative cooling system for fuel pool cooling and
  filtering system.
- We will continuously conduct further water spray depending on the
  conditions of spent fuel pools, if needed. 

Others 
- At 11:00 am on May 10, we started transferring accumulated water from
  the underground level of reactor building to the radiation waste
  treatment facility of Unit 6.
- At approximately 10:00 am on June 13, we started the operation of the
  circulating seawater purification facility installed at the screen area
  of Unit 2 and 3.
- From 8:00 pm on June 17, we started operation of water treatment of
  accumulated water at accumulated water treatment facility. 
- At 6:00 pm on July 2, we started the circulating injection cooling to
  inject the water, which was treated by the accumulated water treatment
  system, to the reactors through the buffer tank.
- From 8:30 am on July 18 to 3:30 pm on July 22, we implemented
  installation work of a temporary roof for the Unit 3 turbine building in
  order to cover the roof's opening as a measure for rainwater.
- From 11 am on July 18 to 6 pm on July 22, accumulated water on the
  basement of Unit 6 turbine building was transferred to a temporary tank.
- On July 21, in order to conduct a restoration work for double circuit of
  Yonomori line which is power source for Unit 5 and Unit 6, we started
  a power switching work to stop the operation of Okuma Line No.3 which
  was connected to Yonomori Line No.1. In addition, on July 23, we 
  implemented work of switching power sources to receive power from Okuma 
  Line No.3. According to this work, we stopped and started the facility
  as follows:
- Alternative cooling facility for the spent fuel pool cooling and
  filtering system of Uni3
  Stopped at 8:02 am on July 21, started at 2:52 pm, and stopped at 3:24 
  am on July 23. 
- Water treatment facility: 
  Stopped at 8:38 am on July 21, started 12:28 am on July22, started water
  treatment of accumulated water at 12:40 am on July 22 and stopped at 
  8:45 am on July 23 
- Common pool:
  Stopped cooling at 8:40 am on July 21, started cooling at 2:41 pm,
  stopped cooling at 3:46 am on July 23 and started cooling at 9:41 am 
- At 4:53 pm on July 22, we started transferring accumulated water at Unit 
  3 turbine building vertical shaft to the Centralized Radiation Waste 
  Treatment Facility (Process Main Building). 
- At 4:56 pm on July 22, we started transferring accumulated water at Unit 
  2 turbine building vertical shaft to the Centralized Radiation Waste 
  Treatment Facility (Process Main Building). 
- At 7:10 am on July 22, the circuit breaker for the bus from Okuma line
  2L which supplies electricity to a part of power network in the power
  station opened the circuit due to overload, resulting in the power off
  of the following facilities: the alternative cooling facility for spent
  fuel pool at Unit 3, water treatment facilities, the cooling facility of
  common pool, monitoring gauges in the reactor of Unit 3 & 4, and Main
  Anti-Earthquake Building. The following facilities which receive power
  from other system had no effect: to water injection and nitrogen gas
  injection to reactor of each unit, each monitoring post, the alternative
  cooling facility for spent fuel pool at Unit 2, monitoring gauges in the
  reactor of Unit 1 & 2, all facilities of unit 5 & 6. After that, we
  found no abnormalities at the secondary side that have been tripped, we
  began receiving electricity from a power network line called TEPCO
  Genshiryoku Sen to complete the restoration works described below:
- At 09:33 am Power source of Main Anti-Earthquake Building
- At 10:35 am Monitoring instruments in Reactor of Unit 3 and 4
- At 10:40 am Cooling System of Common Pool
- At 11:50 am Substitute Cooling Facilities at Spent Fuel Pool Cooling
  and Filtering System of Unit 3
- We started water treatment facility at 3:27 pm and resumed water 
  treatment at 3:51 pm. 
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power station.