ML20137G408

Relief Request BV1-RV-WELDS,Rev 0 to Reactor Vessel Circumferential Welds (RC-R-1-C-1 & RC-R-1-C-8)

ML20137G408
Person / Time
Site:	Beaver Valley
Issue date:	03/12/1997
From:	DUQUESNE LIGHT CO.
To:
Shared Package
ML20137G377	List: ML20137G371 ML20137G408 ML20137G422 ML20137G435 ML20137G444 ML20137G455 ML20137G459 ML20137G465 ML20137G479
References
PROC-970312, NUDOCS 9704010390
Download: ML20137G408 (3)

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e ITYPP-2 INSERVICE INSPECTION PLAN FOR THE SECOND TEN-YEAR INTERVAL AT BEAVER VALLEY POWER STATION UNIT #1 RELIEF REQUEST BVI-RV-WELDS, REV. O SUBJEC7: Reactor Vessel Circumferential Welds (kC-R-1-C-1 and RC-R-1-C-8)

Prepared by:

' Del 4I Date: /

v[f7 Supenisor, inspection and Standards Reviewed by: b, vl 1M Date: 3-ll*97 Director, Nuclear Analysis and @on Reviewed by: D -05C. - G 97 Date: .") /J-f7 OSC Meeting No.

1 Reviewed by: Me(Ne No. 9 T- I Date: > N 97 ORC Me-ting'No.

Approval by: w .n , c- Date: 2 -W ~ b Div. VP Nuclear Orierations / Plant Manager i

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9704010390 970325 PDR ADOCK 05000334 G PDR G

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u DUQUESNE LIGHT COMPANY Beaver Valley Power Station Unit No.1 RELIEF REOUEST NO. BVI-RV-WELDS. Rev. O COMPONENT Reactor Vessel Circumferential Welds (RC-R-1-C-1 and RC-R-1-C-8)

DRAWING NO.

8700-ISI-E-1 A ASME SECTION XI REOUIREMENT (83S83)

Item Nos. Bl. I 1 and Bl.30 (IWB-2500-1, Category B-A) require volumetric examination of essentially 100% of the weld length each 10 year interval. Further,10CFR50.55a(g)(6)(ii)(A) requires that examination requirements for reactor vessel shell welds specified in Item 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. '

l BASIS OF RELIEF j In accordance with 10CFR50 55a(g)(6)(i), reliefis requested on the basis that compliance with the Code requirement is impractical. The flange to upper circumferential shell weld (RC-R-1-C-1) examination is limited due to component geometiy. The lower head to shell weld (RC-R-1-C-8) examination is limited due to interference by the four radial support keyways.

The flange to upper circumferential shell weld (RC-R-1-C-1) was examined using an automated technique during the IRI1 refueling outage. Additionally, a manual UT examination was performed on weld RC-R-1-C-1 from the flange face surface in September 1989 (1st period of the current interval) in accordance with Note 5 of Examination Category B-A.. The first period examination from the flange face surface covered 62% of the weld circumference and used 5 different beam angles (16 out,12* out,6 out,0 , and 6 in, as permitted by ASME V, Article 4, T441.4.2) to cover the required volume. There were no limitations for this examination.

The automated examination of the flange to shell weld (RC-R-1-C-1) was limited to 54% of the required volume due to the inside and outside diameter taper of the flange (see sketch on next page for general configuration). Scan angles of 0 ,45 ,60*, and 70* were used. The movement of the transducer was limited on the inside surface above the mark noted due to the curvature of the flange taper (detailed proprietary vendor supplied drawings are available on site). Considering both examinations (i.e., from the flange face and from the inside ' surface of the vessel wall) approximately 82.5% of the total required volume was examined during the current interval.

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Page 2 of 2 Relief Reauest No. BVI-RV-WELDS. Rev. 0 The automated examination of the lower head to shell weld (C-8) was limited to 85% of the required volume. The four radial support keyways, equally spaced around the circumference, are located adjacent to the weld and preclude the examination of C-8 at these areas.

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Since the examination limitations are due to the geometry of the component or interference by adjacent components, redesign of the reactor vessel would be necessary to completely accomplish the required examinations. It is impractical to redesign the reactor vessel for this purpose. A majority of the required

volume was covered in both cases.

i ALTERNNITVE EXAMINATION The alternative to the examination requirement is to perform the examinations to the maximum extent possible. These examinations are supplemented by the visual exammation performed on the interior of the

, vessel. The four support lugs and the flange to shell weld are included in this examination. Therefore, the UT examinations coupled with the visual examination of the support lugs and the surrounding areas and the visual examination of the interior surface of the flange to shell weld provide an adequate measure of assurance of the integrity of these welds.

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