L-10-132, 0800368.408, Revision 0, Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump Suction and Discharge Nozzle Welds, Core Flood Nozzle Welds, and Cold Leg Drain Nozzle Welds

0800368.408, Revision 0, Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump Suction and Discharge Nozzle Welds, Core Flood Nozzle Welds, and Cold Leg Drain Nozzle Welds

ML101230641
Person / Time
Site:	Davis Besse
Issue date:	04/25/2010
From:	White S Structural Integrity Associates
To:	FirstEnergy Nuclear Operating Co, Office of Nuclear Reactor Regulation
References
L-10-132, Project 0800368, TAC ME0477, TAC ME0478 0800368.408, Rev 0
Download: ML101230641 (12)

Text

Report No. 0800368.408 Revision 0 Project No. 0800368 April, 2010 Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump Suction and Discharge Nozzle Welds, Core Flood Nozzle Welds, and Cold Leg Drain Nozzle Welds at Davis-Besse Nuclear Power Station, Unit 1 Preparedfor:

WSI/FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station Project 0800368 Preparedby.

Structural Integrity Associates, Inc.

San Jose, California Preparedby: Date: 4/25/2010 Steve White Reviewed by: Date: 4/25/2010 Nsor. P.E.

Axline, Approved by: Date: 4/25/2010 Norman Eng, P.E.

V StructuralIntegrityAssociates, Inc.

REVISION CONTROL SHEET Document Number: 0800368.408 Summary of Weld Overlay Ultrasonic Examinations for Reactor Coolant Pump

Title:

Suction and Discharge Nozzle Welds, Core Flood Nozzle Welds, and Cold Leg Drain Nozzle Welds at Davis-Besse Nuclear Power Station; Unit 1 Client: WSI/ FirstEnergy Nuclear Operating ComPany (FENOC)

SI Project Number: 0800368 Quality Program: Z Nuclear F Commercial Section Pages Revision Date Comments 1.0 1-1 2.0 2-1 3.0 3-1 - 3-2 0 4/25/10 Initial Issue 4.0 4-1-4-4 5.0 5-1 V StructuralIntegrityAssociates, Inc.

Table of Contents Section Page

1.0 INTRODUCTION

...................................... ................................................................... 1-1 2.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-126 ................................ 2-1 2.1 Core Flood Nozzle (South) Weld Overlay Examination ............................................. 2-1 2.2 Core Flood Nozzle (North) Weld Overlay Examination ............................................. 2-1 3.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-145 ................................ 3-1 i

3.1 Cold Leg Drain Nozzle 1-2 Weld Overlay Examination...................3-1 3.2 Cold Leg Drain Nozzle 2-1 Weld Overlay Examination ............................................. 3-1 3.3 Cold Leg Drain Nozzle 2-2 Weld Overlay Examination ............................................. 3-2 4.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-149 ................................ 4-1 4.1 Reactor Coolant Pump 1-1 Suction Nozzle Full Structural W eld O verlay Exam ination ..................... i....... ............... ...................................... 4-1 4.2 Reactor Coolant Pump 1-2 Suction Nozzle Full Structural W eld O verlay Exam ination ..................... ................................................................... 4-1 4.3 Reactor Coolant Pump 2-1 Suction Nozzle Full Structural W eld O verlay Exam ination ..................... ................................................................... 4-2 4.4 Reactor Coolant Pump 2-2 Suction Nozzle Full Structural W eld O verlay Exam ination ................................................. ...................................... 4-2 4.5 Reactor Coolant Pump 1-1 Discharge Nozzle Optimized W eld O verlay Exam ination ..................... ................................................................... 4-3 4.6 Reactor Coolant Pump 1-2 Discharge Nozzle Optimized W eld O verlay Exam ination ..................... ................................................................... 4-3 4.7 Reactor Coolant Pump 2-1 Discharge Nozzle Optimized W eld O verlay E xam ination ......................................................................................... 4-4 4.8 Reactor Coolant Pump 2-2 Discharge Nozzle Optimized W eld O verlay Exam ination ..................... ................................................................... 4-4 5.0 RE FERE N CES ............................................................................................................... 5-1 Report No. 0800368.408.Rev. 0 iii V StructuralIntegrity Associates, Inc.

1.0 INTRODUCTION

FirstEnergy Nuclear Operating Company (FENOC) has applied preemptive full structural weld overlays (FSWOLs) and preemptive optimized weld overlays (OWOLs) at the Davis-Besse Nuclear Power Station (Davis-Besse) on Alloy 600.dissimilar metal welds (DMWs) of the components identified herein. The overlays eliminate or reduce the dependence upon the Alloy 82/182 welds as pressure boundary welds and mitigate any potential primary water stress corrosion cracking (PWSCC) in these welds in the future.

The requirements for design of weld overlay (WOLI) repairs are defined in 10 CFR 50.55a Requests RR-A32 and RR-A33, with supplements [1-4], as approved in Nuclear Regulatory i .

Commission (NRC) Safety Evaluations [5, 6]. Thelbasis for FSWOLs is ASME Code Case N-740-2 [8], and for OWOLs the basis is Code Cas* N-740-2 [8] and MRP-169, Revision 1 [9].

This report, which satisfies FENOC Commitment No. 3 of the Relief Requests [ 1], summarizes the final post-implementation ultrasonic examinatiqns performed on the Davis-Besse weld overlays. The examinations were performed using Structural Integrity's, ASME Code,Section XI [7], Appendix VIII, Supplement 11, PDI qualified ultrasonic examination procedures, equipment, and personnel. No unacceptable flaw indications were detected in the overlays or base metal, and no repairs were made to either the base metal or WOLs.

The summaries of the UT Reports include the coverage percentages for both axial and circumferential scanning. Although 100 percent coverage is desired, greater than 90 percent examination coverage is considered as "essentially 100 percent," as documented in ASME Code Case N-460 [10].

Report No. 0800368.408.Rev. 0 1-1 StructuralIntegrityAssociates, Inc.

2.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-126 SI-UT-126, Revision 3, Procedurefor the PhasedArray UltrasonicExamination of Weld OverlaidSimilar andDissimilarMetal Welds, was used during the examinations. This procedure, equipment, and the personnel that applied the procedure, are qualified through the ASME Code,Section XI, Appendix VIII, Supplement 11, PDI program at the EPRI NDE Center.

2.1 Core Flood Nozzle (South) Weld Overlay iExamination Component Identification: Reactor-Vessel Core Flood 1-1 (South) Nozzle Full Structural Weld Overlay ISI Component ID: RC-RPV-WR-53-Y, Nozzle-to'-Safe End Examination Date: 03/28/10 Examination Time: 05:20 - 06:30 ISI Report No.: DB Overlay RC-RPV-WR-53-Y Core Flood 1-1 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: 0' through 840; Circumferential Examination Angles: 0' through 69' Examination Summary: Two flaw indications were detected during the examination, both of which were characterized as laminar flaws. Both laminar flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7] and the Davis-Besse Relief Request RR-A33 [5]. The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5 percent to 20 percent of full screen height. The lower range of examination angles detected responses from the inside surface of the component which were useful for monitoring search unit contact / coupling effectiveness during the examination. 100 percent axial scan and circumferential scan coverage of the ASME Code Case N-740-2 [8] required examination volume, as documented in the Relief Request [5], was achieved during the examinations.

2.2 Core Flood Nozzle (North) Weld Overlay!Examination Component Identification: Reactor Vessel Core Flood 1-2 (North) Nozzle Full Structural Weld Overlay ISI Component ID: RC-RPV-WR-53-W, Nozzle-to-Safe End Examination Date: 03/29/10 Examination Time: 00:30 -01:30 ISI Report No.: DB Overlay RC-RPV-WR-53-W Core Flood 1-2 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: 00 through 840; Circumferential Examination Angles: 0' through 690 Examination Summary: One flaw indication was detected during the examination, which was characterized as a laminar flaw. The laminar flaw was determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7] and the Davis-Besse Relief Request RR-A33 [5].

The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5 percent to 20 percent of full screen height. The lower range of examination angles detected responses from the inside surface of the componenti which were useful for monitoring search unit contact / coupling effectiveness during the examination. 100 percent axial scan and circumferential scan coverage of the ASME Code Case N-740-2 [8] required examination volume, as documented in the Relief Request [5], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 2-1 StructuralIntegrity Associates, Inc.

3.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-145 SI-UT-145, Revision 0, Procedurefor the ManualPhasedArray UltrasonicExaminationof Weld OverlaidSimilar andDissimilarMetal Piping Welds - EPRI-WOL-PA-1, was used during the examinations. This procedure, equipment, and Ipersonnel that applied the procedure, are qualified through the ASME Code,Section XI, Appendix VIII, Supplement 11, PDI program at the EPRI NDE Center.

3.1 Cold Leg Drain Nozzle 1-2 Weld Overlay Examination i

Component Identification: Cold Leg Drain 1-2 Nozzle Full Structural Weld Overlay ISI Component ID: RC-40-CCA-18-3-FW9 Overlay, Nozzle-to-Elbow Weld Examination Date: 04/1/10 Examination Time: 15:01 - 15:22 ISI Report No.: DB Drain 1 WOL Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: 00 through 850; Circumnferential Examination Angles: 0' through 85' Examination Summary: No suspected flaws were observed during the examinations. The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5 percent to 20 percent of full screen height. 100 percent axial scan coverage and 80.1 percent circumferential scan coverage of the ASME Code Case N-740 [8] required examination volume, as documented in the Relief Request [5], was achieved during the examinations. The less than 90 percent circumferential scan coverage was the result of the drain nozzle and attached elbow geometry. Specifically, the fitup of the elbow, and the resulting reduced intrados clearance, prevented interrogation of the inspection volume ori the elbow side.

3.2 Cold Leg Drain Nozzle 2-1 Weld OverlayExamination Component Identification: Cold Leg Drain 2-1 Noz zle Full Structural Weld Overlay ISI Component ID: RC-40-CCA-18-7-FW25 Overlay, Nozzle-to-Elbow Weld Examination Date: 03/11/10 Examination Time: 15:41 - 15:58 ISI Report No.: DB Drain 2 WOL Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld 1 Axial Examination Angles: 00 through 850; Circurnlferential Examination Angles: 00 through 850 Examination Summary: No suspected flaws were observed during the examinations. The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5 percent to 20 percent of full screen height. 100 per6ent axial scan and circumferential scan coverage of the ASME Code Case N-740-2 [8] required examination volume, as documented in the Relief Request [5], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 3-1 StructuralIntegrityAssociates, Inc.

3.3 Cold Leg Drain Nozzle 2-2 Weld Overlay, Examination Component Identification: Cold Leg Drain 2-2 Nozzle Full Structural Weld Overlay ISI Component ID: RC-40-CCA-18-5-FW18 Overlay, Nozzle-to-Elbow Weld Examination Date: 03/15/10 Examination Time: 14:38 - 15:06 ISI Report No.: DB Drain 2 WOL I

Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: 00 through 850; Circumn'ferential Examination Angles: 00 through 85' Examination Summary: No suspected flaws were observed during the examinations. The examination gain was adjusted to maintain the procedure-specified baseline noise level from 5 percent to 20 percent of full screen height. 100 percent axial scan and circumferential scan coverage of the ASME Code Case N-740-2 [8] requiired examination volume, as documented in the Relief Request [5], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 3-2 R StructuralIntegrityAssociates, Inc.

4.0 ULTRASONIC EXAMINATION PROCEDURE - SI-UT-149 SI-UT-149, Revision 3, Procedurefor the Automated PhasedArray UltrasonicExamination of Weld OverlaidPiping Welds, was used during the examinations. This procedure, equipment, and personnel that applied the procedure, are qualified through the ASME Code,Section XI, Appendix VIII, Supplement 11, PDI program at the EPRI NDE Center.

4.1 Reactor Coolant Pump 1-1 Suction Nozzle Full Structural Weld Overlay Examination Component Identification: Reactor Coolant Pump 1-1 Suction Nozzle Full Structural Weld Overlay ISI Component ID: RC-MK-B-67-1-FW134B, Elbow-to-Nozzle Examination Date/Time: 04/12/10 19:27 - 4/14/10!01:52 ISI Report No.: DB Overlay RC-MK-B-67-1-FW134B Suction 1-1 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: -10', 00, 100, 250, 350,1450, 550, 650, and 750 Circumferential Examination Angles: 250, 350, 456, 550, and 650 Examination Summary: During the examination, seven flaws were detected. One flaw was characterized as being laminar and six flaws were characterized as being planar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, ASME IWB-3514 [7] and the Davis-Besse Relief Request RR-A33 [5]. 98.0 percent axial scan coverage and 95.2 percent circumferential scan coverage of the ASME Code Case N-740-2 [8]

required examination volume, as documented in the: Relief Request [5], was achieved during the examinations.

4.2 Reactor Coolant Pump 1-2 Suction Nozzle Full Structural Weld Overlay Examination Component Identification: Reactor Coolant Pump 1-2 Suction Nozzle Full Structural Weld Overlay ISI Component ID: RC-MK-A-67-3-FW105B, Elb'ow-to-Nozzle Examination Date/Time: 04/14/10 21:30 - 4/15/10103:15 ISI Report No.: DB Overlay RC-MK-A-67-3-FWl'05B Suction 1-2 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld i Axial Examination Angles: -10', 00, 100, 250, 350,.450, 550, 650, and 750 Circumferential Examination Angles: 250, 350, 456, 550, and 65° Examination Summary: During the examination, seven flaws were detected. All flaws were characterized as being laminar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7] and the Davis-Besse Relief Request RR-A33 [5].

93.8 percent axial scan coverage and 94.2 percent circumferential scan coverage of the ASME Code Case N-740-2 [8] required examination volume, as documented in the Relief Request [5],

was achieved during the examinations.

Report No. 0800368.408.Rev. 0 4-1 j StructuralIntegrityAssociates, Inc.

4.3 Reactor Coolant Pump 2-1 Suction Nozzle Full Structural Weld Overlay Examination Component Identification: Reactor Coolant Pump 2-1 Suction Nozzle Full Structural Weld Overlay ISI Component ID: RC-MK-A-67-1-FW105A, Elbow-to-Nozzle Examination Date/Time: 04/2/10 16:50 - 4/3/10 00:30 ISI Report No.: DB Overlay RC-MK-A-67-1-FW105A Suction 2-1 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: -10', 00, 100, 250, 350,1450, 550, 650, and 750 Circumferential Examination Angles: 250, 350 450, 550, and 650 Examination Summary: During the examination, three flaws were detected. All flaws were characterized as being laminar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7] and the Davis-Besse Relief Request RR-A33 [5].

100.0 percent axial scan coverage and 94.6 percent ýcircumferential scan coverage of the ASME Code Case N-740-2 [8] required examination volulme, as documented in the Relief Request [5],

was achieved during the examinations.

4.4 Reactor Coolant Pump 2-2 Suction Nozzle Full Structural Weld Overlay Examination Component Identification: Reactor Coolant Pump 2-2 Suction Nozzle Full Structural Weld Overlay ISI Component ID: RC-MK-A-67-2-FW134A, Elb~ow-to-Nozzle Examination Date/Time: 03/30/10 17:35 - 3/31/10101:20 ISI Report No.: DB Overlay RC-MK-A-67-2-FW134A Suction 2-2 Weld Overlay Regions: Overlay, Weld and Base Material (Outer 25 percent) Dissimilar Metal Weld Axial Examination Angles: -10', 00, 100, 250, 35094509 550, 650, and 750 Circumferential Examination Angles: 250, 350, 45*, 550, and 650 Examination Summary: During the examination, noI flaws were detected. 100.0 percent axial scan coverage and 98.4 percent circumferential scan coverage of the ASME Code Case N-740-2

[8] required examination volume, as documented in the Relief Request [5], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 4-2 V StructuralIntegrityAssociates, Inc.

4.5 Reactor Coolant Pump 1-1 Discharge Nozzle Optimized Weld Overlay Examination Component Identification: Reactor Coolant Pump 1-1 Discharge Nozzle Optimized Weld Overlay ISI Component ID: RC-MK-B-59-1-SW143B, Elbbw-to-Safe End Examination Date/Time: 04/14/10 08:39 - 19:41 ISI Report No.: DB Overlay RC-MK-B-59-1-SWI43B I Discharge 1-1 Weld Overlay Regions: Overlay, Weld and Base Mýaterial (Axial Flaws - Outer 25 percent, Circumferential Flaws - 0uter 50 percent) Dissimilar Metal Weld I0 Axial Examination Angles: -10', 00, 100, 250, 35°,145', 550, 650, and 750 Circumferential Examination Angles: 250, 350, 450, 550, and 650 Examination Summary: During the examination, four flaws were detected. One flaw was characterized as being laminar and three flaws were characterized as being planar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514

[7] and the Davis-Besse Relief Request RR-A32 [6]. 98.6 percent axial scan coverage and 92.0 percent circumferential scan coverage of the MRP- 169 [9] required examination volume, as documented in the Relief Request [6], was achieved during the examinations.

4.6 Reactor Coolant Pump 1-2 Discharge Nozzle Optimized Weld Overlay Examination Component Identification: Reactor Coolant Pump 1-2 Discharge Nozzle Optimized Weld Oveilay ISI Component ID: RC-MK-B-44-1-SW69B, Elbow-to-Safe End Examination Date/Time: 04/10/10 15:51 to 23:00 1 ISI Report No.: DB Overlay RC-MK-B-44-1-SW69B Discharge 1-2 Weld Overlay Regions: Overlay, Weld and Base Material (Axial Flaws - Outer 25 percent, Circumferential Flaws - Outer 50 percent) Dissimilar Metal Weld Axial Examination Angles: -100, 00, 100, 250, 350, 450, 550, 650, and 750 Circumferential Examination Angles: 250, 350, 450, 550, and 650 Examination Summary: During the examination, three flaws were detected. All flaws were characterized as being planar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7] and the Davis-Besse Relief Request RR-A32 [6].

99.5 percent axial scan coverage and 100.0 percent circumferential scan coverage of the MRP-169 [9] required examination volume, as documented in the Relief Request [6], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 4-3 StructuralIntegrityAssociates, Inc.

4.7 Reactor Coolant Pump 2-1 Discharge Nozzle Optimized Weld Overlay Examination Component Identification: Reactor Coolant Pump 2-1 Discharge Nozzle Optimized Weld Overlay ISI Component ID: RC-MK-B-61-1-SW69A, Elbow-to-Safe End Examination Date/Time: 03/22/10 16:34 - 3/23/101 00:32 ISI Report No.: DB Overlay RC-MK-B-61-1-SW69A Discharge 2-1 1

Weld Overlay Regions: Overlay, Weld and Base Material (Axial Flaws - Outer 25 percent, Circumferential Flaws - Outer 50 percent) Dissimilar Metal Weld I

Axial Examination Angles: -100, 00, 100, 250, 350,1450, 550, 650, and 750 i

Circumferential Examination Angles: 250, 350, 450, 550, and 650 Examination Summary: During the examination, four flaws were detected. Two flaws were characterized as being laminar and two flaws were characterized as being planar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7]

and the Davis-Besse Relief Request RR-A32 [6]. 9,8.9 percent axial scan coverage and 100.0 percent circumferential scan coverage of the MRP-169 [9] required examination volume, as documented in the Relief Request [6], was achievecd during the examinations.

4.8 Reactor Coolant Pump 2-2 Discharge Nozzle Optimized Weld Overlay Examination Component Identification: Reactor Coolant Pump 2-2 Discharge Nozzle Optimized Weld Overlay ISI Component ID: RC-MK-B-56-1-SW143A, Elbow-to-Safe End Examination Date/Time: 03/24/10 11:30 - 3/25/101 00:19 ISI Report No.: DB Overlay RC-MK-B-56-1-SW143A Discharge 2-2 Weld Overlay Regions: Overlay, Weld and Base Material (Axial Flaws - Outer 25 percent, Circumferential Flaws - Outer 50 percent) Dissimilar Metal Weld Axial Examination Angles: -10', 00, 100, 25', 350,[450, 550, 65', and 750 1

Circumferential Examination Angles: 250, 350, 450, 550, and 650 Examination Summary: During the examination, two flaws were detected. One flaw was characterized as being laminar and one flaw was characterized as being planar. All flaws were determined to be acceptable in accordance with both ASME Code,Section XI, IWB-3514 [7]

and the Davis-Besse Relief Request RR-A32 [6]. 99.45 percent axial scan coverage and 100.0 percent circumferential scan coverage of the MRP- 169 [9] required examination volume, as documented in the Relief Request [6], was achieved during the examinations.

Report No. 0800368.408.Rev. 0 4-4 V StructuralIntegrityAssociates, Inc.

5.0 REFERENCES

1. FENOC Letter to Nuclear Regulatory Comlpission (NRC), 10 CFR 50.55a Requests for Alternative Dissimilar Metal Weld Repair Methods for Reactor Vessel Nozzles, Reactor Coolant Pump Nozzles, and Reactor Coolant Piping, January 30, 2009, L-09-020.

[ADAMS Accession No. ML090350070]

2. FENOC Letter to NRC, Response to Reque~ts t for Additional Information Related to Alternative Dissimilar Metal Weld Repair Methods, July 13, 2009, L-09-179. [ADAMS Accession No. ML091950627]

3. FENOC Letter to NRC, Response to Requests for Additional Information Related to Alternative Dissimilar Metal Weld Repair Methods, November 23, 2009, L-09-268.

[ADAMS Accession No. ML093360333]

4. FENOC Electronic Mail to NRC, Relief Requests A-32 and A-33, December 15, 2009.

[ADAMS Accession No. ML100040016]

5. NRC Letter to FENOC, Davis-Besse Nuclear Power Station, Unit 1 - Relief Request RR-A33 for the Application of Full Structural Weld Overlays on Dissimilar Metal Welds of Reactor Coolant Piping, January 21, 2010.

[ADAMS Accession No. ML100080573]

6. NRC Letter to FENOC, Davis-Besse Nuclear Power Station, Unit 1 - Relief Request RR-A32 for the Application of Full Structural Weld Overlays on Dissimilar Metal Welds of Reactor Coolant Piping, January 29, 2010.

[ADAMS Accession No. ML100271531]

7. American Society of Mechanical Engineers I(ASME) Boiler and Pressure Vessel Code (ASME Code),Section XI, 1995 Edition thr ough 1996 Addenda.

8. ASME Code Case N-740-2, "Dissimilar Metal Weld Overlay for Repair or Mitigation of Class 1, 2, and 3 Items."

9. Electric Power Research Institute (EPRI), "Materials Reliability Program: Technical Basis for Preemptive Weld Overlays for All y 82/182 Butt Welds in PWRs (MRP-169),"

Revision 1, EPRI, Palo Alto, CA; and Structural Integrity Associates, Inc., San Jose, CA; 1016602, June 2008.

10. ASME Code Case N-460, "Alternate Examination Coverage for Class 1 and Class 2 Welds"Section XI, Division 1.

Report No. 0800368.408.Rev. 0 5-1 V StructuralIntegrityAssociates, Inc.