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Corporate Information

 
Press Release (Jul 03,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 3:00 pm, July 3)
 
*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 which is now powered by the off-site transmission line. Water is currently injected at approx. 3.5m3/h through reactor feed water system piping arrangement. - We commenced injection of nitrogen gas into Primary Containment Vessel 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. At 6:27 pm on June 23, we changed the water injection line so that we can inject water to Unit 1 and 2 by the motor driven pump for Unit 1 and stopped the motor driven pump for Unit 2. Water is currently injected at approx. 3.5m3/h through reactor feed water system piping arrangement. - 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 11:01am 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. Water is currently injected at approx. 9 m3/h through 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. - At 7:47 pm on June 30, we started cyclic cooling of the spent fuel pool in Unit 3 using alternative cooling system for fuel pool cooling and filtering system. - 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. - 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 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. - From 8:00 pm on June17, we started operation of water treatment of accumulated water at accumulated water treatment facility. - At 9:56 am on June 22, we started transferring accumulated water in turbine building of Unit 2 to central waste treatment facility building. - At 8:56 am on June 30, we started transferring the accumulated water from the basement of the turbine building of Unit 3 to Centralized Radiation Waste Treatment Facility (Process Building). - At 7:27 am on July 1, we stopped injecting treated water and started injecting only filtrate water, for the installation of the tank (buffer tank) for injection to the reactor. At 2:22 pm on July 2, the installation work of the buffer tank was completed. At 6:00 pm on the same day, 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 10:00 am on July 1, we started transferring of low radioactive stored water from outdoor temporary tank to Mega Float. - At 10:00 am on July 1, we started transferring of accumulated water from inside of turbine building of Unit 6 to temporary tank. - At 6:55 am on July 3, in the outside temporary seawater cooling pumps (2 pumps) used for the cooling for the reactor of Unit 5, we found a leakage of seawater from the water pipe (exit side) of one pump. And we stopped the other pump as well. After that we finished to change the piping at 1:19 pm and started to operate 2 pumps, recommenced to operate reactor residual heat removal system at 1:40 pm. - At 10:39 am on July 3, we stopped accumulated water treatment system to change the Cesium adsorption tower and recommenced it at 12:50 pm - 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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