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Corporate Information

 
Press Release (May 08,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 10:00 am, May 8)

*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.
-At 10:01 am on May 6th, in order to make nuclear reactor flooded to the
 top of Fuel range, we have increased the amount of injecting freshwater
 from approximately 6 m3/h to approximately 8m3/h. 
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 
-On May 7th, we sprayed water to Unit 4 by the concrete pumping vehicle
 from 2:05 pm to 5:30 pm. 
-We will continuously conduct further water spray depending on the
 conditions of spent fuel pools, if needed. 
Others 
-The transfer of high level radioactive wastewater in Unit 2 to the
 Centralized Radiation Waste Treatment Facility was temporarily suspended
 at 9:22am on May 7th, due to construction of injection piping (reactor
 feeding water system) to reactor of unit3. The construction work has 
completed and we re-started the transfer at 4:02 pm. 
-From March 27, transfer of accumulated water in Unit 5 turbine building
 to a condenser has been conducted, and water with the amount of
 approximately 600 m3 has been transferred from March 27 to May 2.
 From May 2, we have started work relating to the set up of exhausters, in
 order to improve the working environment inside the reactor building of
 Unit 1. At 4:36 pm on May 5th, all of exhausters (6 units) were started
 to operation. 
-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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