ML20137G455

Relief Request BV2-B3.110-2,Rev 0 to Pressurizer Nozzle-to-Vessel Welds

ML20137G455
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-970312-04, PROC-970312-4, NUDOCS 9704010399
Download: ML20137G455 (3)

Text

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l 2TYPP-1 I INSERVICE INSPECTION PLAN FOR THE FIRST TEN YEAR INTERVAL AT BEAVER VALLEY POWER STATION UNIT #2 RELIEF REQUEST BV2-B3.110-2, REV. O j

SUBJECT:

Pressurizer Nozzle-to-Vessel Welds Prepared by: nwM--- b / DPv) Date: 'la0l47 Supenisof, Inspection and Standards Resiewed by: b. d L AAS Date: 3-ll- %

Director, Nuclear Analysis and ins on Reviewed by: D - O S C 6 'i7 Date: d I8G li 7 OSC Meeting No.

Resiewed by: N 4< b ^ % )Oo. $'I- I Date: d [ A l'f 7 ORC Meeting Mo.

Approval by: , wn [ t&_e Date: .? -/ 2 - 9 )

Div. VP, Nuclear Operations / Plant Manager 9704010399 970325 PDR ADOCK 05000334 G PDR m

DUQUESNE LIGHT COMPANY )

Beaver Valley Power Station Unit No. 2 RELIEF REOUEST NO. BV2-B3.110-2. Rev. O  !

l COMPONF21

. Pressurizer Nozzle-to-Vessel Welds:

2RCS* PRE 21-N-10 (6" relief nozzle) 2RCS' PRE 21-N-13 (6" relief nozzle)  ;

2RCS* PRE 21-N-11 (6" relief nozzle) 2RCS* PRE 21-N-14 (4" spray nozzle) l 2RCS* PRE 21-N-12 (6" relief nozzle)

ASME SECTION XI REOUIREMENT (83S83)

Item No. B3.110 (IWB-2500-1, Category B-D) requires volumetric examination. 1 I

BASIS OF RELIEF l

l In accordance with 10CFR50.55a(g)(6)(i), reliefis requested on the basis that compliance with the Code I requirement is impractical. Ultrasonic examinations were performed on the Pressurizer nozzle-to-vessel I upper head welds. These examinations were limited due to the nozzle curvature. The curvature of the outside surface causes the transducer to lose contact with the surface. Each of these welds are essentially )

identical in configuration. The table below identifies the examination coverage for the welds for each scan j angle used. j Examination Angle ( ) Examination Direction  % of WRV Examined Limitation 0 N/A 80 nozzle curvature 45 1 85 nozzle cuwature 45 2 32  !

nozzle cunature _

45 both 32 nozzle curvature 60 1 92 nozzle curvature 60 2 16 nozzle curvature 60 both 16 nozzle curvature 45 & 60 3 80 nozzle curvature 45 & 60 4 80 nozzle curvature The examination volume calculations are based on the required examination volume illustrated in ASME Section XI, Figure IWB-2500-7(b). The limitations preventing full coverage are inherent to the design of these nozzles. There are no current NDE methods that would appreciably increase the amount of the examination coverage (see attached sketch for the nozzle configuration and the scan limitations).

ALTERNATIVE EXAMINATION The alternative to the examination requirement is to perform the ultrasonic examination to the maximum extent possible. The UT technique used provides the maximum coverage possible, considering the nozzle design and materials used in fabrication. j H

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