ML20202B162
| ML20202B162 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 10/03/1997 |
| From: | Legrand R DUQUESNE LIGHT CO. |
| To: | |
| Shared Package | |
| ML20202A937 | List: |
| References | |
| NUDOCS 9712030066 | |
| Download: ML20202B162 (2) | |
Text
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INSERVICEINSPECTION PLAN FOR THE FIRST TEN. YEAR INTERVAL AT DEAVER VALLEY POWER STATION UNIT #2
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RELIEF REQUEST BV2 AUG-1, REY. 0 l
SUBJECT:
ReacW Vessel 14wer Circuadersetlal Weld (2RCS REV21 C-4)
M 4/ EDD Date: 8 6**i'T Prepared by:
Superviior, Nuclear Programs Resiewed by:
Date:
8 ft 7 Director, Design Basinngineering 9
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Raicwed by: ANil y 9 /10 /9 7 Roiewed by:
BV-05C. -Mo CJ7 Date:
OSC 9/sl97 Rniewed by:
Reneo b%t for Meehe 97-+
Date:
ORC Approval by:
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Date: /6 3 - 9 >
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Div. VP, Nuclear Op'crations / Flant Manager 971203o066 971124
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DUQUESNE LIGHT COMPANY Beaver Valley Power Station Unit No. 2 RELIEF REOUEST NO. BV2-RV AUG-1. Rev. O COMPONENT Reactor Vessel Lower Head Circumferential Weld (2RCS-REV21-C-4)
DRAWING NO.
10080 ISI E-1 A AUGMENTED REOUIREMENT 10CFR50.55a(gX6XiiXA) requires that examination requirements for reactor vessel shell welds specified in Itere Bl.10 of Examination Category B A in Table IWB-2500-1 of subsection IWB of the 1989 Edition of Section XI be implemented as part of the current inspection interval.
BASIS OF RELIEF In accordance with 10CFR50.55a(gX6)(i), reliefin requested on the basis that compliance with the Code requirement is impractical. The lower head to shell weld (2RCS-REV21-C-4) examination is limited due to the four core support lugs.
This weld was examined using automated techniques during the 2R06 refueling outage. Over eighty-nine percent (89%) of the required volume was examined. The four lugs are welded to the inside surface of the reactor vesseljust above weld 2RCS-REV21-C-4 10CFR50.55a(gX6XiiXA) defines " essentially 100%", for the purposes of the augmented examination, as more than 90 percent of the examination volume of each weld, where the reduction in coverage is due to interference by another component, or part geometry. To obtain the last 1% of the required volume would necessitate removal of one of the support lugs. Removal of a support lug for this purpose is considered impractical.
PROPOSED ALTERNATIVE TO THE RULE The alternative to the rule is to perform the examination to the maximum extent possible. This examination is supplemented by the visual examination performed on the interior of the vessel. The four support lugs are included in this examination. Therefore, the UT examination coupled with the sisual examination of the support lugs and the surrounding areas provides an adequate measure of assurance of the integrity of this weld.
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