search



Corporate Information

 
Press Release (Aug 01,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, Aug 1)
There are no updates from the previous press release. 
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. 3.6 m3/h through 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. 
  Water is currently injected at approx. 3.6 m3/h through 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. 8.9m3/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 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 don't think there is any reactor coolant leakage
  inside the primary containment vessel. 
Unit 5 (Outage due to regular inspection) 
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 5 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 time, we don't think there is any reactor coolant leakage
  inside the primary containment vessel. 
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 to cool down Spent Fuel Pool.
- At 7:27 pm on March 20, the reactor achieved cold shutdown.  
- At this time, we don't think there is any reactor coolant leakage
  inside the primary containment vessel. 
Operation for cooling the Spent Fuel Pools 
- At 5:21 pm on May 31, we started cyclic cooling of Spent Fuel Pool of
  Unit 2 by using alternative cooling system of the Pool's cooling and
  filtering system.
- At 7:47 pm on June 30, we started cyclic cooling of Spent Fuel Pool of
  Unit 3 by using alternative cooling system of the Pool's cooling and
  filtering system.
- At 0:44 am on July 31, we started cyclic cooking of Spent Fuel Pool of
  Unit 4 by using alternative cooling system of the Pool's cooling and
  filtering system. 
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 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.
- At 8:00 pm on June 17, we started operation of Water Treatment Facility
  against the accumulated water. 
- 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.
- At 11:04 am on July 30, we started transferring accumulated water at
  spent fuel common pool building to the water desalinations tank. 
- At 4:10 pm on July 30, we started transferring accumulated water at
  Unit 2 turbine building to Centralized Radiation Waste Treatment
  Facility.
- At 4:13 pm on July 30, we started transferring accumulated water at
  Unit 3 turbine building to Centralized Radiation Waste Treatment
  Facility.
- From 10:00 am to 5:00 pm on July 31, we transferred low level
  accumulated water at temporary tank to Mega Float.
- From 11:00 am to 4:00 pm on July 31, we transferred the accumulated
  water from T/B, Unit 6 to Temporary Tank. 
back to page top


to TOP