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Corporate Information

 
Press Release (Nov 06,2008)
Status of the Inspection and Restoration Works Performed after the Niigata-Chuetsu-Oki Earthquake (as of November 6th)
We are announcing the status of major inspections and restoration works and nonconformances 
at TEPCO's Kashiwazaki-Kariwa Nuclear Power Station after the Niigata-Chuetsu-Oki Earthquake. 

Inspection/Restoration Status

 ○ Inspection and restoration completed between October 31st to November 6th, 2008 
    (Completed on the following date) 

   • Unit No.1 Stack inspection (Unit No.1 and 2 Additional inspection of pile): 
      October 31st 
   • Unit No.4 Inspection of power supply input transformer of the primary loop recirculation 
    system adjustable speed drive (Transportation into the factory): 
      November 5th 
   • Unit No.6 Main transformer inspection (Installation work): 
      November 6th 
   • Unit No.6 House transformer inspection (6A and 6B Installation work): 
      October 31st 
   • Unit No.6 500kV power cable inspection: 
      October 31st 
   • Unit No.7 Reactor head reopening: 
      To be completed on November 6th 
   • Unit No.7 Stack inspection (Inspection of stack radiation monitor sampling pipe):
      November 3rd 
   • Unit No.7 Seismic reinforcement works (Seismic reinforcement works such as pipe supports): 
      November 3rd
   • Unit No.7 Seismic reinforcement works (Seismic reinforcement works for fuel handling machine): 
      November 1st 

 ○ Inspection and restoration to be commenced between November 7th to November 13th, 2008 
    (To be commenced on the following date) 

   • Unit No.1 Main exhaust duct inspection and restoration (Restoration of substruction): 
      November 10th 
   • Unit No.2 Main exhaust duct inspection and restoration (Restoration of substruction): 
      November 10th 
   • Unit No.3 Main exhaust duct inspection and restoration (Restoration of substruction): 
      November 10th 
   • Unit No.5 Main exhaust duct inspection and restoration (Restoration of substruction): 
      November 10th 
   • Unit No.7 Fuel-load work: 
      November 8th 
   • Unit No.7 Turbine inspection (Low-pressure turbine (A) Restoration work of casing): 
      November 11th 

 ○ Work Schedule of Major Inspection/Restoration from November 2nd to November 29th, 2008

    • Work Schedule of the Main Inspection/Restoration of the Kashiwazaki-Kariwa Nuclear 
      Power Station in Response to the Niigata-Chuetsu-Oki Earthquake (during 4 Weeks)
                                                                            ....Appendix

 (Reference) 
   Nonconformances Found in the Inspection and Restoration Works Performed after the 
   Niigata-Chuetsu-Oki Earthquake

   Based on the "Public Announcement Regarding Nonconformance Found in the Inspection 
   and Restoration Works Performed after the Niigata-Chuetsu-Oki Earthquake", the Tokyo 
   Electric Power Company, Incorporated (TEPCO) provides this announcement containing 
   incidents information reported from October 30th to November 5th, 2008. 

  ○ Incidents Information (relating to the Chuetsu-Oki Earthquake)
Incidents Information (relating to the Chuetsu-Oki Earthquake)
< Reports from October 30 to November 5, 2008 >
Reports from October 30 to November 5, 2008, 2008
○ Other Findings - During in-core inspection of Unit No.5, on November 29th, 2007, one of the 20 jet pumps* was found to have its wedge-installed to repress vibration during operation-dislocated. Other jet pumps were inspected and found to be intact (announced on November 29th and December 3rd, 2007). The wedge is assumed to have dislocated due to loosened fixture bracket of the upper jet pump. When the bracket was replaced during the 4th regular outage carried out on May to June 1995, bolts of the bracket were fastened with a minute foreign material attached. The foreign material subsequently became loose due to vibration during operation, leading to loosening of the bracket and dislocation of the jet pump. Based on evaluation using seismic load during the Chuetsu-Oki earthquake and mock-up testing, the dislocation was confirmed to have occurred not due to the earthquake. No abnormal flow was observed from past operational data of the jet pump. Thus there was no functional issue with the jet pump. All jet pumps are verified of their integrity through daily operational data and procedures are defined to cope with abnormal events. We will confirm there is no abnormal condition after replacing fixture brackets of jet pumps as a countermeasure. The jet pump at issue of unit 5 will be securely fixed with a repair wedge. No non-conformance that will affect function or performance has been found in other units. However, we will inspect Unit No.4 since it has experienced replacement of jet pump fixture bracket in the past and detailed confirmation has not been carried out. * Jet pumps are static pumps without rotating parts that circulate reactor coolant water by utilizing pressurized water by reactor primary loop recirculation pump.
Appendix: Work Schedule of the Main Inspection/Restoration of the Kashiwazaki-Kariwa Nuclear
          Power Station in Response to the Niigata-Chuetsu-Oki Earthquake (during 4 Weeks)
                                                                                (PDF 44.7KB)


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