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Corporate Information

 
Press Release (Apr 30,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, April 30)
*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 nuclear
 reactor through the feed water system was initiated.
-From 3:37 pm on March 25, we started injecting freshwater and are now
 injecting fresh water by a motor driven pump powered by the off-site
 transmission line. From on April 27, we have increased the amount of
 injecting freshwater from approximately 6 m3/h to approximately 14 m3/h.
 At 10:14 am on April 29, we put the amount of injecting freshwater back
 to approximately 6 m3/h.
-As it is suspected that hydrogen gas is accumulated inside reactor
 containment vessel, we commenced the valve opening operation concerning
 injection of nitrogen gas into the reactor container vessel at 10:30 pm
 April 6th 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 fresh water by a motor driven pump powered by the
 off-site transmission line. 
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. 
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 the Nuclear
 Reactor Building.
-At this moment, we do not consider any reactor coolant leakage inside the
 reactor happened. 
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 reactor cold shutdown. 
-At this moment, we do not consider any reactor coolant leakage inside the
 reactor happened. 
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 reactor cold shutdown. 
-At this moment, we do not consider any reactor coolant leakage inside the
 reactor happened. 
Operation for cooling the spent fuel pools 
-We will continuously conduct further water spray depending on the
 conditions of spent fuel pools, if needed. 
Others 
-Regarding the transfer of high level radioactive wastewater in Unit 2 to
 the Centralized Radiation Waste Treatment Facility, while we temporarily
 suspended transfer due to the inspection of transferring facilities at
 9:16 am on April 29, transfer was restarted at 2:05pm on April 30. 
-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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