ML20202B251

Pressure Testing Program for Third Ten-Yr Interval at Bvps,Unit 1 & Second Ten-Yr Interval at Bvps,Unit 2,Relief Request BV3-IWA-2,Rev 1, Re Class 1,2 & 3 Bolting Removal Due to Leakage

ML20202B251
Person / Time
Site:	Beaver Valley
Issue date:	10/03/1997
From:	Legrand R DUQUESNE LIGHT CO.
To:
Shared Package
ML20202A937	List: L-97-067, Requests NRC Review & Approval of Proposed Relief Requests Applicable to Plant,Units 1 & 2 10-yr ISI Programs.Listed Revised & Proposed Relief Requests,Encl ML20202A955 ML20202B134 ML20202B148 ML20202B162 ML20202B175 ML20202B251
References
PROC-971003, NUDOCS 9712030081
Download: ML20202B251 (2)

Text

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PRESSURE TESTING PROGRAM AT BVPS UNIT #1, FOR THE THIRD TEN YEAR INTERVAL AND BVP2 UNIT #2, FOR THE SECOND TEN YEAR INTERVAL RELIEF REQUEST BVJ IWA 2, REY.1

SUBJECT:

Class 1,2, and 3 Botting Removal Due to leakage Prepared by: Afd b' SD6 Date: d-l0i7 Supenisor' Nuclear Programs Roiewed by: w . Date: f!E/

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0 DUQUESNE LIGir COMPANY Beaver Valley Power Station Unit Nos. I and 2 RELIEF REOUEST NO. BV3 lWA 2 Rev.1 COMPONENT Class I,2, and 3 pressure retaining bolted connections.

ASMI.f0DE SECIl0XXI.REQUIREMINIII.9.MIditlan) ash 01 Secuon XI,1989 Edition, Subparagraph IWA 5250(aX2) states, "if leakage occurs at a b>lted rem %

tie bolting shall bc removed, VT 3 visually examined for corrosion, and mluated in accordarwe with IWA.3100.'

B ASIS OF. RELIEF in mocordance with 10CFR50.$$a(aX3Xil) reliefis isquested from the ASME Section XI,1989 Edition, Subparagraph IWA 5250(aX2) requirement that if leckage occurs at a bolted e'**% tie bolting shall be removed, VT 3 visually examinat for corrosion, and evt luated in accordance with IWA 3100. Compliance with tie Code requirements would result in hardt hip and t,nu.ual dif5culty without a compensating increase in the inet of quality and safety. Irabge at a bolted connection may be a significant variable in the degradation mechanism of bolicii connections. Ilowever, leakage is not the only variable and in some cases may not be de degradation mechanism. Bolting materials, leaking medium, luration of de leak, and location of the leak are other variables to be considered. Removal of bolting at a mechanical connection may not be the most prudent decision to make.

All variables should be considered before disassembling a bolted connection for a sisual examination. Duquesne l Light promes an alternative to tie requirements ofIWA $2!0(aX2) that will prmide an equh alent inel of quality and safety at Class 1,2, and 3 bolted connecdons.

PROPOSED ALTERNATIVE EXAMINATION Leakage on Code Class 1,2, and 3 bolted connections shall be evaluated to determine the susceptibility of dw botting to corrosion and potential future failure. This rniew will consider as a minimum, location of leakage, histo.y of leakage, bolted connection materials, visual midence of corrosion with tie connection assernbled, corrosiveness of the process fluid, history and studies of similar bolted material in a similar emironment, and other components in the vicinity that may be degraded due to the leakage. If this imiew assures the integrity of the connection, no bolting will be rernoved for examination. If this resiew canrot assure the integrity of the connection, the bolt closest to the leakage source shall be removed, VT.I examined and evaluated in accordance with IWA 3100(a). Whr a the renmed bolt has rejectable degradition, the remaining bolts will be removed, VT.I examined and evaluated in accordance with IWA 3100(a). If no degradation is observed on the removcd bolt, no further action will be required.

Duquesne Light requests NRC approval of the proposed alternathe requirements for Class 1,2, and 3 bolted connections in lieu of those o(IWA 3250(aX2). NRC approval is requested in a time frame that will support implementation of the alternathe requirements for the Unit I twelfth refueling outage currendy scheduled to begin in September of 1997. Unit I twelfth refueling outage will be the first outage of the third ten year interval at Beaver Valley Power Station Unit No.1. The second ten year interval at Beawr Valley Power Station Unit No. 2 will begin November 17,1997, a

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