search



Corporate Information

 
Press Release (Jan 18,2012)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 10:00 am, January 18)
*The 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, 2011. It was assumed to be hydrogen 
  explosion.
- At 3:37 pm on March 25, 2011, 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. 
- At 10:11 am on December 10, 2011, in addition to water injection from 
  water feeding system, we started water injection from piping of core 
  spray system to the reactor.
  Since fluctuation of the water injection rate was confirmed at 9:53 am 
  on January 18, 2012, we adjusted injection rate from feeding piping from 
  approx. 4.8m3/h to approx. 4.5 m3/h, and injection rate from core spray 
  water injecting piping from approx. 1.8 m3/h to approx. 2 m3/h. 
  The Current water injection volume is approx. 4.5 m3/h from the reactor 
  feed water system and approx. 2.0 m3/h from the core spray system.
- At 1:31 am on April 7, 2011, we commenced injection of nitrogen gas into 
  Primary Containment Vessel.
- At 11:22 am on August 10, 2011, we started cyclic cooling for the water 
  in the spent fuel pool by an alternative cooling equipment of the Fuel 
  Pool Cooling and Filtering System. 
- On October 28, 2011, we completed installation of the cover for the 
  Reactor Building in order to contain dispersion of radioactive 
  substances.
- At 4:04 pm on November 30, 2011, we started operation to inject nitrogen 
  into the reactor pressure vessel.
- At 6:00 pm on December 19, 2011, a full-scale operation of the PCV gas 
  management system started.
Unit 2 (Shut down) 
- At approximately 6:00 am on March 15, 2011, an abnormal noise began 
  emanating from nearby Pressure Suppression Chamber and the pressure 
  within the chamber decreased. 
- At 10:10 am on March 26, 2011, 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. 
- At 2:59 pm on September 14, 2011, in addition to water injection from 
  water feeding system, we started water injection from piping of core 
  spray system to the reactor.
  Since fluctuation of the water injection rate was confirmed at 9:53 am 
  on January 18, 2012, we adjusted injection rate from feeding piping from 
  approx. 2.4m3/h to approx. 3.0 m3/h, and injection rate from core spray 
  water injecting piping from approx. 7.5 m3/h to approx. 7.0 m3/h. 
  The Current water injection volume is approx. 3.0 m3/h from the reactor 
  feed water system and approx. 7.0 m3/h from the core spray system.
- At 5:21 pm on May 31, 2011, we started cyclic cooling for the water in 
  the spent fuel pool by an alternative cooling equipment of the Fuel Pool 
  Cooling and Filtering System. 
- At 8:06 pm on June 28, 2011, we started injecting nitrogen gas into the 
  Primary Containment Vessel.
- At 6:00 pm on October 28, 2011, a full-scale operation of the PCV gas 
  management system started.
- At 10:46 am on December 1, 2011, we started the nitrogen injection to 
  the Reactor Pressure Vessel.
Unit 3 (Shut down) 
- Explosive sound and white smoke were confirmed at approximately 11:01 am 
  on March 14, 2011. It was assumed to be hydrogen explosion.
- At 6:02 pm on March 25, 2011, 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 2:58 pm on September 1, 2011, we started water injection by core 
  spray system in addition to water injection by the reactor feed water 
  system piping arrangement.
- At 9:43 am on January 18, 2012, in conjunction with switching injection 
  piping of reactor injection pump on the hill, we adjusted the amount of 
  the water injection from approx. 1.9 m3/h to approx. 3.0 m3/h through 
  the reactor feed water system, from approx. 7.5 m3/h to approx. 6.0 m3/h 
  through the core spray system.  
  The Current water injection volume is approx 3 m3/h from the reactor 
  feed water system and approx. 6.0 m3/h from the core spray system.
- At 7:47 pm on June 30, 2011, we started cyclic cooling for the water in 
  the spent fuel pool by an alternative cooling equipment of the Fuel Pool 
  Cooling and Filtering System.
- At 8:01 pm on July 14, 2011, injection of nitrogen gas into the Primary 
  Containment Vessel started. 
- At 4:26 pm on November 30, 2011, we started operation to inject nitrogen 
  into the reactor pressure vessel.
- At 3:18 pm on January 14, we started operation of the radioactive 
  material removal instrument for the spent fuel pool in Unit 3
Unit 4 (Outage due to regular inspection) 
- At around 6 am on March 15, 2011, we confirmed the explosive sound and 
  the sustained damage around the 5th floor rooftop area of Reactor 
  Building.
- At 12:44 pm on July 31, 2011, we started cyclic cooling for the water in 
  the spent fuel pool by an alternative cooling equipment of the Fuel Pool 
  Cooling and Filtering System (from 1:30 pm to 3:14 pm on January 12, 
  2012, we injected hydrazine [corrosion inhibitor] in conjunction with 
  the cyclic cooling).
- At 10:58 am on November 29, 2011, in order to decrease more salinity, we 
  installed Ion exchange equipment and started the operation of such 
  equipment.
- 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 5:00 am on March 19, 2011, we started the Residual Heat Removal 
  System Pump in order to cool the spent fuel pool.
- At 2:45 pm on July 15, 2011, we started the operation of the original 
  Residual Heat Removal System (System B) by its original seawater pump.
- At 10:11 am on December 22, 2011, since we finished the recovery work of 
  seawater pump (System B) of equipment water cooling system, we made a 
  trial run. At 11:25 am on the same day, we confirmed no abnormalities 
  and restarted the operation.
- At this moment, 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, 2011, we started the Residual Heat Removal 
  System Pump of Unit 6 to cool down Spent Fuel Pool.
- At 2:33 pm on September 15, 2011, we started separately cooling the 
  reactor through the Residual Heat Removal System and the spent fuel pool 
  through Equipment Cooling Water System and Fuel Pool Cooling System.
- At this moment, we do not think there is any reactor coolant leakage 
  inside PCV.
Others 
- At around 10:00 am on June 13, 2011, 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, 2011, 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 7:41 pm on August 19, 2011, we started treatment of accumulated water 
  by parallel operation of one line from the cesium adsorption instrument 
  to the decontamination instrument and the other treatment line of the 
  cesium adsorption instrument No.2.
- At 2:06 pm on October 7, 2011, we started to spray purified accumulated 
  water brought from Unit 5 and 6 continually in order to prevent dust 
  scattering and potential fire outbreaks from the cut down trees.
- On October 28, 2011, we started installation of the water proof wall at 
  the sea side, in front of the existing shore protection, Units 1-4, in 
  order to contain marine pollution by underground water.
- At 12:25 pm on December 13, 2011, we started the re-circulating 
  operation of desalination facility (reverse osmosis membrane type) for 
  the purpose of suppression of condensed water after desalination 
  treatment.
- As finding of accumulated water containing radioactive materials at the 
  trench between the Process Main Building and the Miscellaneous Solid 
  Waste Volume Reduction Treatment Building [High Temperature Incinerator 
  Building] (December 18, 2011), we started the inspection of other 
  trenches at the site on January 11.
  As a result of the inspection of January 17, the locations where 
  accumulated water was discovered and the nuclide analysis results 
  (preliminary results) are as follows:
  - Unit 4 Chemical tank joint duct 
     I-131:Not detected, Cs-134:1.3 x 100Bq/cm3,Cs-137:1.7 x 100Bq/cm3 
  - Unit1 Spare power resources cable duct 
     I-131:Not detected, Cs-134:5.4 x 10-1Bq/cm3,Cs-137:8.0 x 10-1Bq/cm3 
  - We confirmed that no accumulated water in the Unit 3 Chemical tank 
    joint duct and Unit 2 radioactive fluid piping. 
  - At around 4:10 pm on January 17, 2012, due to defect of switching gear 
    at Minami-Iwaki switching station, Yonomori line 1 and 2 were 
    instantaneously shut down. Facilities which were shut down due to the 
    effect of this are described below. We confirmed there is no problem 
    on the facilities which were shut down and sequentially re-started on 
    the same day. Also there is no big change on major parameter by this 
    shut down. 
  - Nitrogen inclusion facility of Unit 1 to 3 [activated on 4:57 pm] 
  - Alternative cooling system for spent fuel pool of Unit 2 [Activated on 
    4:53 pm] 
  - Alternative cooling system for spent fuel pool of Unit 3 [Activated on 
    5:15 pm] 
  - Cooling and filtering system for spent fuel pool of Unit 6 [Activated 
    on 5:19 pm] 
  - Gas control system of Primary Containment Vessel of Unit 2 [Activated 
    on 5:25 pm] 
  - Cesium adsorption apparatus [Activated on 6:42 pm, reached steady flow 
    rate on 6:45 pm] 
  - Radioactive material removal system of spent fuel pool of Unit 3 
    [Activated on 7:04 pm] 
back to page top


to TOP