Print

Language



Corporate Information

 
Press Release (Jul 08,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, July 8)
  
*Updates are underlined time 
 
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 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. At 6:27 pm on June 23, we changed the water injection line so 
  that we can inject water to Unit 1 and 2 by the motor driven pump for 
  Unit 1 and stopped the motor driven pump for Unit 2. 
  Water is currently injected at approx. 3.3m3/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 m3/h through 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 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 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. 
- From 8:20 am to 2:24 pm on July 8, we turned off the alternative cooling 
  system for fuel pool cooling and filtering system of Unit 3 in 
  accordance with the power cable relocation aimed to prevent the 
  interference to the installation of reactor building cover and the 
  installation of alternative cooling system for fuel pool cooling and 
  filtering system of Unit 4. 
- 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 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 June17, we started operation of water treatment of 
  accumulated water at accumulated water treatment facility. 
- From 9:56 am on June 22 to 3:10 pm on July 7, we transferred accumulated 
  water from turbine building of Unit 2 to central waste treatment 
  facility building. 
- At 8:56 am on June 30, we started transferring the accumulated water 
  from the basement of the turbine building of Unit 3 to Centralized 
  Radiation Waste Treatment Facility (Process Building). 
- 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 10:30 am to 4:30 pm on July 7, we transferred accumulated water 
  from turbine building of Unit 6 to the temporary tank. 
- From 10:09 am to 5:00 pm on July 7, we transferred low radioactive 
  stored water from the outdoor temporary tank to Mega Float. 
- From 8:22 am to 1:52 pm on July 8, we injected fresh water to the 
  reactor well and the dry separator pit of Unit 4 in order to reduce 
  radiation dose on the 5th floor of the reactor building of Unit 4. 
- At 10:00 am on July 8, we started transferring low radioactive stored 
  water from the outdoor temporary tank to Mega Float. 
- At 10:00 am on July 8, we stopped the accumulated water treatment 
  facility (cesium adsorption instrument) in order to replace cesium 
  adsorption tower. Afterwards we started up the facility at 12:04 pm and 
  resumed the accumulated water treatment at 12:15 pm. 
- At 10:30 am on July 8, we started transferring the accumulated water in 
  the turbine building of Unit 6 to the temporary tank. 
- From 10:34 am to 1:49 pm on July 8, we measured the air dose of 2nd and 
  3rd floors of the reactor building of Unit 2 by robot. 
- From 1:35 pm to 1:44 pm on July 8, the worker confirmed the condition of 
  nitrogen inclusion line by high-place work vehicle. 
- We will continue to take all measures to ensure the safety and to 
  continue monitoring the surrounding environment around the power station.  
back to page top