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Corporate Information

 
Press Release (Jun 19,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 10:00 am, June 19)
*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.
-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 powered by the off-site transmission line. We are now 
 injecting freshwater by a motor driven pump powered by the off-site 
 transmission line. Current injected water amount is approx. 4.5 m3/h 
 through feed water system.
-As it was suspected that hydrogen gas had been accumulated inside Primary 
 Containment Vessel, in order to prevent increase in density of oxygen, we 
 commenced the valve opening operation concerning injection of nitrogen 
 gas into the primary containment vessel at 10:30 pm on April 6 and 
 commenced injection 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 
 and are now injecting freshwater by a motor driven pump powered by the 
 off-site transmission line. 
 The current rate of water injection is approx. 5 m3/h through the reactor 
 feed water system piping arrangement. 
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.
 The current rate of water injection is approx. 11.5 m3/h through the 
 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. 
-From 4:05 pm to 7:23 pm on June 18, the injection of fresh water to spent 
 fuel pool of Unit 4 was implemented using temporary water injecting 
 system (hydrazine was also injected from 4:29 pm and completed at 6:33 pm 
 on same day) 
-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. On May 27, we started spraying dust inhibitor to Turbine Building 
 of Units 1, and implemented spraying the dust inhibitor to other turbine 
 and reactor buildings of Units 1 to 4 and completed on June 18th. 
-At 2:00 pm on May 1, we started transferring accumulated water in the 
 turbine building of Unit 6 to temporary tanks.
-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 12:42 pm on June 11, we started to operate local exhausters in order 
 to improve inside environment of Unit 2 Reactor Building.
-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.
-At 2:20 pm on June17, we started transferring accumulated water in the 
 vertical shaft (trench) of the turbine building of Unit 2 to the 
 condenser in the turbine building of Unit 1. However, at 2:59 pm we 
 stopped the operation of the transfer pump since water flux was not 
 observed. The cause is currently under investigation.
-From 8:00 pm on June17, we started operation of water treatment of 
 accumulated water at accumulated water treatment facility. At 0:54 am on 
 June18, we stopped operation of the facility temporarily due to the 
 radiation dose at surface level measured up to the basis of exchange 
 filter of Cesium adsorption Instruments.
-At 1:31 pm on June 18, we started transfer of accumulated water at 
 basement level in the Unit 3 turbine building to the centralized 
 radiation waste treatment facility (Miscellaneous Solid Waste Volume 
 Reduction Treatment Building).
-We will continue to take all measures to ensure the safety and to 
 continue monitoring the surrounding environment around the power station. 
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