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Press Release (Sep 27,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, Sep. 27)
*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. It was assumed to be hydrogen explosion.
-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 ㎥/h through reactor feed 
 water system piping arrangement. 
-We commenced injection of nitrogen gas into Primary Containment Vessel 
 at 1:31 am on April 7.
-At 11:22 am on August 10, 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. 
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. 
-At 2:59 pm on September 14, we started injecting water to the reactor 
 through core spray system water injection piping arrangement in addition 
 to the water injection through reactor feed water system piping 
 arrangement.
 Water is currently injected at approx. 3.8 ㎥/h through reactor feed 
 water system piping arrangement, and at approx. 6 ㎥/h through core spray 
 system water injection piping arrangement.
-From 5:21 pm on May 31, 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, we started injecting nitrogen gas into the Primary 
 Containment Vessel. 
Unit 3 (Shut down)  
-Explosive sound and white smoke were confirmed at approximately 11:01 am
 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.
-From 2:58 pm on September 1, we started water injection by core spray 
 system in addition to water injection by the reactor feed water system 
 piping arrangement. 
 Water is currently injected at approx. 2.7 ㎥/h through reactor feed 
 water system piping arrangement, and at approx. 8 ㎥/h through core spray 
 system water injection piping arrangement.
-From 7:47 pm on June 30, 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, injection of nitrogen gas into the Primary 
 Containment Vessel started. 
Unit 4 (Outage due to regular inspection)  
-At around 6 am on March 15, we confirmed the explosive sound and the 
 sustained damage around the 5th floor rooftop area of Reactor Building.
-From 12:44 pm on July 31, 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 1:57 pm on September 27, we also 
 started injection of hydrazine [corrosion inhibitor].)  
-From 11:34 am on August 20, we started an operation of desalination
 equipment in the spent fuel pool.
-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, we started the Residual Heat Removal System Pump
 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 (System B) by its original seawater pump.
-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
 of Unit 6 to cool down Spent Fuel Pool.
-At 7:27 pm on March 20, the reactor achieved cold shutdown.
-At 2:33 pm on September 15, 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 time, we don't think there is any reactor coolant leakage inside
 the primary containment vessel. 
Others  
-At around 10 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 7:41 pm on August 19, 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 9:51 am on September 13, we started transferring accumulated water
 from the turbine building of Unit 2 to High Temperature Incinerator
 Building of Centralized Radiation Waste Treatment Facility. 
-At 9:54 am on September 15, we started transfer of the accumulated 
 water from the turbine building of Unit 3 to Centralized Radiation 
 Waste Treatment Facility.
-From 10:00 am to 4:00 pm on September 26, we transferred the accumulated
 water from the turbine building of Unit 6 to the temporary tank.
-At 11:05 am on September 26, one of the staff from the cooperating
 companies was injured catching his forth finger between the steel stocks
 in site of the power plant (outdoors). The staff returned to the office
 outside the site and headed for the emergency medical office of Unit 5/6 
 with a surgical mask on. Contamination on the surface of the body and the 
 surgical mask is not detected. As a result of the measurement by whole 
 body counter, which was conducted in case, we have evaluated that no 
 radioactive materials was taken in. 
-At 11:05 am on September 27, on the second floor of the turbine building 
 of Unit 5, while draining lubricant oil of overhead crane to drums for 
 inspection of the crane, one of our employees found lubricant oil was 
 leaked on the floor. The amount of the leaked oil was approximately 8 
 liters, and at about 1:00 pm, we wiped the oil from the floor. 
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