*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 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 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.
 
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 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.
- At this moment, we do not consider any reactor coolant leakage inside
  the reactor happened.
 
Operation for cooling the spent fuel pools 
- From 1:40 pm to 2:00 pm on April 22nd, we conducted injection of 
  freshwater to Unit 3 by the fuel pool cooling and filtering system on 
  trial base. 
- From 2:19 pm to 3:40 pm on April 22nd, we conducted spraying water to 
  Unit 3 by the concrete pumping vehicle. 
- We will conduct further water spray depending on the conditions of
  spent fuel pools, if needed.
 
Others 
- The national government has instructed evacuation for those local
  residents within 20km radius of the periphery and shelter in place for
  those residents from 20km to 30km radius of the periphery, because it is
  possible that radioactive materials are discharged.
- At 10:08 am on April 19th we started transferring high level radioactive
  wastewater to the Centralized Radiation Waste Treatment Facility.
- From 11:30am to 2:00pm, we opened and closed the double doors and
  conducted surveys of the situation of the inside of the nuclear reactor
  building of Unit 3 and measured a dose of radiation, etc. by a remote
  control robot.  Also, from 4:00pm to 5:30pm, we did the same kind of
  work on Unit 1. From 1:42pm to 2:33pm on April 18th, we opened and
  closed the double doors, measured a dose of radiation and so on, and
  conducted surveys of the situation of the inside of the nuclear reactor
  building of Unit 2, by a remote control robot.
- From 11:43am to 0:50pm on April 21st, an unmanned helicopter flew over
  Units 1 to 4 to confirm the conditions around the building of those
  Units.
- We will continue to take all measures to ensure the safety and to
  continue monitoring the surrounding environment around the power station.