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Information of Kashiwazaki-Kariwa Nuclear Power Station (The 8th news)
- Status of main inspection and restoration work (1) -

　 At present, the Kashiwazaki Kariwa Nuclear Power Station is systematically and steadily undertaking detailed inspections and restoration work on its equipment and facilities, with the results of the inspections to be released as they become available.JANTI will summarize the findings and release them in coming months. This Report #8 introduces the current status of main inspection and restoration work.
　 Report #6 provided the “update on the overall situation through to August 10”.Our next report will give another update on subsequent progress made.

1. Status of main inspection and restoration work

(1) Completed items

Unit Inspection equipment Completion date

Unit 1 Upper reactor (Phase 1 of the in-core inspection) Completed on August 23 (See Section 2 for details.)

Main transformer Exterior inspection completed on August 29

In-house transformer (1A) Internal inspection completed on September 4

Operating floor service tool (working dolly) Completed on September 13

Unit 2 Ceiling crane in the turbine building Inspection completed on August 24

Unit 3 In-house transformer (3A) Exterior inspection completed on September 4

Unit 7 Ceiling crane in the reactor building Completed on September 6

(2) Overall status

　 The overall status of inspection and restoration work is listed in the attachment.The overall status will be revised as the work progresses.

2. In-core inspection

(1) Inspection policy

○ 　 Tokyo Electric Power Company commenced inspection work on Unit 1, which was in the midst of outage and had its reactor pressure vessel head already opened, and Unit 7, which has a different type of reactor (ABWR) to Unit 1.Using underwater lighting and underwater cameras, visual inspection is conducted on reactor internals from refueling machines or working dollies to check for damage, significant deformation and dislodgment or other abnormalities in mechanical joints (such as bolts and mating parts).

○ 　 Visual inspection will also be carried out from above fuel structures at all plants that had fuel loaded in their reactors at the time of the earthquake (Units 2 to 7) to identify any damage or significant disfigurement of fuel assemblies and control rods.

(2)

Overall inspection schedule (planned):Excerpt from TEPCO press release dated September 6

(3)

Inspection results

○

　 In-core inspection (Phase 1) was conducted on Unit 1 from August 21 to 23, to find no damage, deformation or dislodgment of parts.

○

　 In-core inspection (Phase 2:Inspection of the mid reactor --- the reactor core) on Unit 1 is scheduled for September 14 to October 1.

【Reference】

　 The internals of a reactor are visually checked from above with an underwater camera, before the implementation of further inspection on the area extending from the reactor pressure vessel flange to the upper grid plate, with the aim of checking the internal status of the reactor.

　 An underwater camera is used to visually check the area extending from the upper grid plate to the core support plate, as well as the outer circumference of the core shroud (annulus).The dryer and separator, removed from the core, are also examined.

　 Inspection is carried out on the area extending from the core support plate to the bottom of the reactor, after removing control rods, fuel supports and other items that could interfere with the inspection.

Related information on in-core inspection on Unit 1 (posted on the TEPCO website)

　　　　Status of in-core inspection 　　　　　　　　 Inspection schedule

End

Japan Nuclear Technology Institute
Rev.0
September 19, 2007