RIS 2004-16, Draft RAI, Extend the First Period of the Fourth 10-year Inservice Inspection Interval

Draft RAI, Extend the First Period of the Fourth 10-year Inservice Inspection Interval

ML071510345
Person / Time
Site:	Quad Cities
Issue date:	05/16/2007
From:	Thorpe-Kavanaugh M NRC/NRR/ADRO/DORL/LPLIII-2
To:	Schrage J Exelon Corp
Thorpe-Kavanaugh, Meghan, LPL3-1
Shared Package
ML071510364	List: RIS 2004-16, Draft RAI, Extend the First Period of the Fourth 10-year Inservice Inspection Interval
References
RIS-04-016
Preceding documents:	ML042590067 (19 October 2004)
Download: ML071510345 (2)

DRAFT REQUEST FOR ADDITIONAL INFORMATION

QUAD CITIES NUCLEAR POWER STATION, UNIT 1 DOCKET NOS. 50-254 By letter dated May 11, 2007, Exelon Generation Company (Exelon) requested relief from the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code,Section XI. The relief request, 14R-16, proposed to extend the first period of the fourth 10-year inservice inspection interval at Quad Cities Nuclear Power Station (QCNPS), Unit 1. The NRC

staff has determined that the following information is needed in order to complete its review:

1. In Section 6.0, Duration of Proposed Alternative, of Relief Request 14R-16, the licensee requested the first inspection period for examination of the subject RPV welds for QCNPS

Unit 1 be extended until one of the three options occurs. The staff has the following questions regarding those statements:

(A) Describe how the current inspection procedures will be re-qualified and re-certified by PDI as described in the first provision.

(B) Discuss whether the ultrasonic examination procedures that were used in the 2005 examination were previously qualified and certified by the PDI. If not, discuss how the

2005 ultrasonic examination procedures were qualified and by what standards.

(C) The staff has concerns regarding the wording used in the second provision (i.e., the ASME Code Inquiry). The staff cannot use ASME Code Inquiry as a regulatory basis for its decisions. In addition, ASME Subcommittees approval does not imply that the NRC

would approve the inquiry. The regulatory authority resides with the NRC, not the ASME. The staff would find acceptable if requirements for the equivalency demonstration of cable and connectors are added to the latest ASME Code,Section XI

and that the NRC approves the changes to the ASME Code through NRCs regulatory process. In addition, licensees who wish to use the provisions of an edition and addenda of the ASME code later than their ISI code of record must be approved by the NRC with a licensee request to use a later edition and addenda of the ASME Code (Regulatory Issue Summary 2004-16). Therefore, the licensee should consider removing this option as written from consideration or modifying the request to be consistent with the regulatory process outlined above.

2. Provide the scheduled end date for QCNPS Unit 1 refueling outage 20.

3. Describe the examination history of the subject welds including previous examination schedules and results.

4. On page 2, third paragraph, of Relief Request 14R-16, the licensee stated the worst case configuration consisted of 1350 feet of RG-58 coaxial cable, plus 230 feet of RG-174 coaxial cable, plus 5 feet of Micro Cable and a total of 20 connectors. Describe the actual cable lengths that were qualified for the cable configuration by the PDI organization.

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5. On page 2, last paragraph, of Relief Request 14R-16, the licensee stated that the maximum length of cable that was used in 2005 is greater than that quantified for cable type RG-174.

The licensee used 230 feet of cable in the 2005 examination. It seems that the licensee is using the same (not greater) length of cable. Clarify the statement regarding the cable length used in 2005.

6. Discuss the impact of difference in the number of connectors on the examination results because the licensee used 6 connectors whereas the worst case configuration had 20

connectors. Discuss the impact on examination results of difference in cable length and type of cables (i.e., RG-58 and RG-174) between the 2005 examination at QCNPS and PDI qualified procedures.

7. In light of the staffs concern regarding the qualification of the ultrasonic examination, discuss the probability of flaw(s) in the subject RPV welds that may not be detected. Discuss the structural integrity of the subject RPV welds until May 2009, considering the crack growth of the undetected flaw(s).

Attachment 1