search



Corporate Information

 
Press Release (Jun 12,2011)
Plant Status of Fukushima Daiichi Nuclear Power Station (as of 10:00 am, June 12)
 
*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. The current rate of water injection is approx. 5 m3/h through reactor feed water system piping arrangement. - As it was suspected that hydrogen gas had been accumulated inside Primary Containment Vessel, 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. - 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. We will implement spraying the dust inhibitor to other turbine and reactor buildings of Units 1 to 4. - 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 6:39 pm on June 4, we started transferring accumulated water from vertical shafts (trenches) of turbine building of Unit 2 to Process Main Building. - 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 3:30 pm on June 11, we started transferring accumulated water from the basement of Unit 3 Turbine Building to Centralized Radiation Waste Treatment Facility (Process Main Building). - We will continue to take all measures to ensure the safety and to continue monitoring the surrounding environment around the power station.
back to page top


to TOP