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Corporate Information

 
Press Release (Jan 08,2012)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, January 8)
*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.
 Current water injection volume is approx. 4.6 m3/h from the reactor feed
 water system and approx. 1.9 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.
 Current water injection volume is approx. 1.9 m3/h from the reactor feed
 water system and approx. 8 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. 
 Current water injection volume is approx 2.9 m3/h from the reactor feed
 water system and approx. 6 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. 
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.
-At around 1:00 pm on January 8, at circulating cooling system for spent 
 fuel pool of unit 4, we found water leakage from 4 points of cooling pipe 
 of air fin cooler (System B) when we tried to conduct scheduled switching 
 of air fin cooler (From System A to System B). Currently, we are 
 investigating the cause of the leakage. Leaked water is purified water 
 (pure water)* and is not contained radioactive materials. Now we secluded 
 the air fin cooler from the system to prevent the spread of water leakage. 
 In addition, the cooling of spent fuel pool has no problem because we are 
 currently using air fin cooler (System A) to cool spent fuel pool. 
 * Purified water (pure water): The water from Sakashita dam 
-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 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 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.
-At 10:00 am on January 8, 2012, we started to transfer accumulated water
 from the basement of turbine building of Unit 6 to temporally tank. 
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