ML18152B400

Requests Relief from Certain Impractical Requirements of ASME Section XI Code Associated with Partial Exams Conducted During 1998 Surry Unit 1 Refueling Outage.Relief Request SR-020 Encl

ML18152B400
Person / Time
Site:	Surry
Issue date:	07/29/1999
From:	Hartz L VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
99-336, NUDOCS 9908030123
Download: ML18152B400 (7)

Text

e e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 July 29, 1999 United States Nuclear Regulatory Commission Serial No.: 99-336 Attention Document Control Desk NL&OS/GDM: RO Washington, D. C. 20555 Docket No.: 50-280 License No.: DPR-32 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNIT 1 ASME SECTION XI RELIEF REQUEST SR-020 During the 1998 Surry Unit 1 refueling outage, Surry Power Station Unit 1 completed examinations in the second period of its third ten year inservice inspection interval. The component examination program is conducted in accordance with the 1989 Edition of the ASME Section XI Code.

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from certain impractical requirements of the ASME Section XI Code associated with partial examinations conducted during the Surry Unit 1 outage. Specifically, ASME Section XI requires that all Class 1 nozzle-to-safe end butt welds on the steam generators receive surface and volumetric examinations as specified in Category 8-F, for dissimilar metals, and Figure IWB 2500-8 of the Code. The inlet and outlet nozzle to pipe welds on the "B" steam generator are of this type; however, the close proximity of the nozzle and pipe elbow physically limits the volumetric examination.

Relief Request SR-020 (attached) further discusses the examination and provides the basis for the requested relief. The request has been approved by the Surry Station Nuclear Safety and Operating Committee.

A similar relief request, Relief Request SR-012, for welds 1-05DM and 1-06DM (hot and cold legs for "A" steam generator on Surry Unit 1) was approved by NRC letter dated August 30, 1996.

If you have any questions concerning this request, please contact us.

Very truly yours,

~~

L. N. Hartz - { /

Vice President - Nuclear Engineering and Services 9908030123 990729---~~--~,,

PDR ADOCK.05000280 G PDR

Attachment cc: U.S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. R. A. Musser NRC Senior Resident Inspector Surry Power Station Mr. Robert Smith Authorized Nuclear Inspector Surry Power Station

e Virginia Electric & Power Company Surry Power Station Unit 1 Third Ten Year Interval Relief Request No. SR-020 I. Identification of Components:

Weld No. Line No. Drawing No. Class 1-05DM 29"-RC-4-2501 R 11448-WMKS-0101AZ-1 1 1-06DM 31"-RC-5-2501 R 11448-WMKS-0101AZ-1 1 Welds 1-05DM and 1-06DM are nozzle-to-safe end butt welds on the "B" loop steam generator (hot and cold legs, respectively) reactor coolant piping.

11. Code Requirements The 1989 Edition of ASME Section XI Table IWB-2500-1, examination category B-F, item number B5. 70 requires an OD surface examination of the weld and adjacent base metal and a volumetric examination of the weld and adjacent base metal (interior one-third volume) as defined by Figure IWB-2500-8. The Code does not allow any limitations to the required volumetric or surface examinations.

Code Case N-460, Alternative Examination Coverage for Class 1 and Class 2 Welds, allows a reduction in coverage, if it is less than 10 percent.

111. Code Requirement from Which Relief is Requested Relief is requested from fully performing the Code-required volumetric examination on the above identified reactor coolant piping welds.

IV. Basis for Relief The components listed above have been examined to the extent practical as required by the Code. However, due to the configuration of the weld (proximity to nozzles and elbows), full volumetric coverage could not be achieved in the axial direction. Coverage of the volumetric and surface examinations is detailed in Table SR-20-1. Figure SR-020-1 is provided as graphic detail of the limitations experienced.

The material on the elbow side of the joint is centrifugally cast stainless steel which requires a large, dual element, longitudinal wave search unit. A centrifugally cast stainless steel calibration block is also used. A smaller transducer or a shear wave transducer would not provide adequate calibration or Page 1 of 5

adequate penetration into the material. Due to the cladding on the nozzle and

. the base material of the elbow, as well as the geometry and ultrasound node, the use of a multi-leg inspection technique was not possible.

100% of the welds in this Category and item number are scheduled for examination. Therefore, substitution with other welds is not feasible.

V. Proposed Alternate Examination The examination performed at reduced coverage is proposed to be fully acceptable to meet the Code requirements. In addition:

1) A visual (VT-2) examination will be performed during the normally scheduled leakage test each refueling outage.

1) Technical Specifications require that the reactor coolant system leak rate be limited to one gallon per minute unidentified leakage. This value is calculated daily.

2) The containment atmospheric particulate radioactivity is checked every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> as an early indicator of RCS leakage.

The proposed alternate examination will ensure that the overall level of plant quality and safety will not be compromised.

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Figure SR-020-1 Weld 1-0SDM Inlet Nozzle 5 2 e

Elbow Side Nozzle Side 45 degree beam angles used Flow Required Exam Area UT Reading Achieved

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Figure SR-020-1 Weld 1-06DM Outlet Nozzle 2 5 Elbow Side Nozzle Side 45 degree Flow beam angles used Required Exam Area UT Reading Achieved Page 4of5

Table SR-020-1 Surry Unit 1 Examination Coverage Estimates (Piping) 11448-WMKS-0101AZ-1 Category 8-F, Item 85. 70 Weld UT Scan Coverage % Surface Coverage % Reasons for Partial No.

2 5 7 8 e 1-05DM O 65 100 100 100 Pipe to steam generator nozzle to safe-end configuration prevented_ scanning from the nozzle side and prevented full scanning from the elbow side. The use of alternate angles would not have improved coverage.

1-06DM 73 0 100 100 100 Pipe to steam generator nozzle to safe-end configuration prevented scanning from the nozzle side and prevented full scanning from the elbow side. The use of alternate angles would not have improved coverage.

UT Scan Direction Definitions 2 - axial scan, 180 degrees from isometric flow direction 5 - axial scan, the same direction as the isometric flow 7 - circumferential scan, clockwise direction when viewing in direction of isometric flow 8 - circumferential scan, counter-clockwise direction when viewing in direction of isometric flow Page 5 of 5