ML12109A100

Evaluation of Inservice Inspection Relief Requests ISIR-33 Through ISIR-42

ML12109A100
Person / Time
Site:	Cook
Issue date:	04/26/2012
From:	Istvan Frankl Plant Licensing Branch III
To:	Weber L Indiana Michigan Power Co
Tam P
References
TAC ME6087, TAC ME6088
Download: ML12109A100 (57)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 26, 2012 Mr. Lawrence J. Weber Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman. MI 49106

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 - EVALUATION OF INSERVICE INSPECTION RELIEF REQUEST NOS. ISIR-33 THROUGH ISIR-42 (TAC NO. ME608? AND ME6088)

Dear Mr. Weber:

By letter dated April 8, 2011, as supplemented by letter dated March 6, 2012, Indiana Michigan Power Company (the licensee) submitted a request to the U.S. Nuclear Regulatory Commission (NRC) for relief from the requirements of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for certain weld examination coverage requirements specified in ASME Code,Section XI, 1989 Edition, as amended by Title 10 of the Code of Federal Regulations (10 CFR), Section SO.SSa(b).

Specifically, pursuant to 10 CFR SO.SSa(g)(6)(i), the licensee requested relief and approval to use alternative requirements (if necessary). for in-service inspection on the basis that the code requirement is impractical for several components due to access limitations caused by design at the Donald C. Cook Nuclear Plant, Units 1 and 2.

The NRC staff has reviewed the subject request and concludes that ASME Code examination coverage requirements are impractical for the subject welds listed in relief requests ISIR-33 through ISIR-42. The licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR SO.SSa(g)(6)(i), and is in compliance with the requirements of 10 CFR SO.SSa with the granting of these reliefs.

Details of the NRC staff's review are set forth in the enclosed Safety Evaluation.

L. J. Weber

- 2 If you have any questions, please contact the Project Manager, Mr. Peter Tam, at (301) 415-1451.

Sincerely,

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Istvan Frankl, Acting Chief Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316

Enclosure:

Safety Evaluation cc w/encl: Distribution via ListServ

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION INSERVICE INSPECTION RELIEF REQUEST NOS. ISIR-33 THROUGH ISIR-42 INDIANA MICHIGAN POWER COMPANY DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NO. 50-315 AND 50-316

1.0 INTRODUCTION

By letter dated April 8, 2011, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 1111 OA042). as supplemented by the letter dated March 6, 2012 (ADAMS Accession No. ML12076A027), Indiana Michigan Power Company (I&M, the licensee) requested relief from the requirements of the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code (B&PV Code) for certain weld examination coverage requirements specified in American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section XI, 1989 Edition, as amended by Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(b).

Specifically, pursuant to 10 CFR 50.55a(g)(6)(i), the licensee requested relief and approval to use alternative requirements (if necessary) for in-service inspection items on the basis that the code requirement is impractical for several components due to access limitations caused by design.

The relief requests are for the third inspection interval, which concluded on April 9, 2010, at the Donald C. Cook Nuclear Plant (CNP), Units 1 and 2. The relief requests are detailed in ISIR-33, ISIR-34, ISIR-35, ISIR-36, ISIR-37, ISIR-38, ISIR-39, ISIR-40, ISIR-41 and ISIR-42.

2.0 REGULATORY EVALUATION

Inservice inspection of the ASME Code Class 1, 2, and 3 components is to be performed in accordance with Section XI of the ASME Code, and applicable addenda, as required by 10 CFR 50.55a(g). except where specific relief has been granted by the Commission pursuant to 10 CFR 50.55a(g)(6)(i). The regulation at 10 CFR 50.55a(a)(3) states that alternatives to the requirements of paragraph (g) may be used, when authorized by the Nuclear Regulatory Commission (NRC). if the licensee demonstrates that (i) the proposed alternatives would provide an acceptable level of quality and safety or (ii) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

Enclosure

- 2 Pursuant to 10 CFR 50.55a(g)(4), ASME Code Class 1, 2, and 3 components (including supports) shall meet the requirements, except the design and access provisions and the preservice examination requirements, set forth in the ASME Code,Section XI, to the extent practical within the limitations of design, geometry, and materials of construction of the components. The regulations require that inservice examination of components and system pressure tests conducted during the first 1 O-year interval and subsequent intervals comply with the requirements in the latest edition and addenda of Section XI of the ASME Code, which was incorporated by reference in 10 CFR 50.55a(b) 12 months prior to the start of the 120-month interval, subject to the limitations and modifications listed therein. The ASME Code of record for CNP, Units 1 and 2, third 10-year interval inservice inspection program, which ended on April 9, 2010, is the 1989 Edition, with no Addenda, of Section XI of the ASME B&PV Code.

The licensee noted in its April 8, 2011, submittal that relief is requested for the Third 10-year inspection interval for CNP Units 1 and 2, which began on July 1, 1996, and ended April 9, 2010, at the conclusion of the Unit 1 Cycle 23 Refueling Outage. Significant long-term outages (greater than six months) occurred multiple times during the interval and the interval was extended as allowed by IWA-2430(e) and by IWA-2430(d) to accommodate interval planning and scheduling.

3.0 TECHNICAL EVALUATION

The information provided by the licensee in support of the requests for relief from, or alternatives to, ASME Code requirements has been evaluated and the bases for disposition are documented below.

3.1 RR ISIR-33 AS ME Code,Section XI. Examination Category B-A. Items B1.11. B1.12, B1.21. B1.22. and B1.30 Pressure Retaining Welds in Reactor Pressure Vessel and ASME Code.Section XI. Examination Category B-D. Item B3.90 (CNP, Unit 1) 3.1.1 ASME Code Components ASME Code Class:

Code Class 1 ASME Code,Section XI, B-A, Pressure Retaining Welds in Reactor Vessel (RPV)

Examination Category:

B-D, Full Penetration Welds of Nozzles in Vessels I nspection Program B (RPV only)

ASME Code,Section XI, B1.11, Shell Welds - Circumferential; B1.12, Shell Welds Item Numbers:

Longitudinal; B1.21, Head Welds - Circumferential; B1.22, Head Welds - Meridional; B1.30, Shell to Flange Weld; B3.90, RPV - Nozzle to Vessel Welds The component identifications and details are listed in Table 3.1.

- 3 Table 3.1 Component 10 Weld Description ASME

Code,Section XI Item Number Ultrasonic Examination Coverage Attained (Percentage)

Remarks CPN, Unit 1 1-RPV-A Shell to Flange 81.30 84.44 The completed examination was limited to 84.4 percent coverage due to the configuration. The limitations are due to flange configuration, specimen slots, and keyways at 0, 90, 180, and 270 degrees. No recordable indications detected.

CPN, Unit 1 1-RPV-D Lower Shell-to-8ottom Head 81.11 82.60 The completed examination was limited to 82.60 percent coverage due to the configuration. The limitations are due to six core support lugs. No recordable indications detected.

CPN, Unit 1 1-RPV-E Dollar Plate 81.21 38.4 The completed examination was limited to 38.4 percent coverage due to the configuration. The limitation is due to the bottom mounted instrument penetrations. No recordable indications detected.

CPN, Unit 1 1-RPV-VC1 Lower Shell Longitudinal at 60 Degrees 81.12 78.29 The completed examination was limited to 78.29 percent coverage due to the configuration. The limitation is due to the core support lug. No recordable indications detected CPN, Unit 1 1-RPV-VC2 Lower Shell Longitudinal at 180 Degrees 81.12 78.29 The completed examination was limited to 78.29 percent coverage due to the configuration. The limitation is due to the core support lug. No recordable indications detected CPN, Unit 1 1-RPV-VC3 Lower Shell Longitudinal at 300 Degrees 81.12 78.29 The completed examination was limited to 78.29 percent coverage due to the configuration. The limitation is due to the core support lug. No recordable indications detected.

CPN, Unit 1 1-LHM-01 Lower Head Meridional at 30 Degrees 81.22 79.0 The completed examination was limited to 79.0 percent coverage due to the configuration. The limitation is due to bottom mounted instrumentation penetrations. No recordable indications detected.

-4 Component Weld 10 Description ASME

Code,Section XI Item Number Ultrasonic Examination Coverage Attained (Percentage)

Remarks CPN, Unit 1 Lower Head B1.22 73.26 The completed examination was 1-LHM-02 Meridional at 90 Degrees limited to 73.26% coverage due to the configuration. The limitation is due to bottom mounted instrumentation penetrations. No recordable indications detected.

CPN, Unit 1 Lower Head B1.22 88.1 The completed examination was 1-LHM-05 Meridional at 270 Degrees limited to 88.1 % coverage due to the configuration. The limitation is due to bottom mounted instrumentation penetrations. No recordable indications detected.

CPN, Unit 1 Lower Head B1.22 74.5 The completed examination was 1-LHM-06 Meridional at 330 Degrees limited to 74.5% coverage due to the configuration. The limitation is due to bottom mounted instrumentation penetrations. No recordable indications detected CPN, Unit 1 Outlet Nozzle to B3.90 71.08 The completed examination was 1-N3B Shell at 22 Degrees limited to 71.08% coverage due to the configuration. The limitation is due to nozzle geometry, vessel saddle effect, and adjacent outlet nozzle protrusion. Two subsurface indications were detected and evaluated as acceptable to IWB-3512-1.

CPN, Unit 1 Outlet Nozzle to B3.90 71.08 The completed examination was 1-N4B Shell at 158 Degrees limited to 71.08% coverage due to the configuration. The limitation is due to nozzle geometry, vessel saddle effect, and adjacent outlet nozzle protrusion. One subsurface indication was detected and evaluated as acceptable to i

IWB-3512-1.

CPN, Unit 1 Outlet Nozzle to B3.90 71.08 The completed examination was 1-N1B Shell at 202 Degrees limited to 71.08% coverage due to the configuration. The limitation is due to nozzle geometry, vessel saddle effect and adjacent outlet nozzle protrusion. Six subsurface indications were detected and evaluated as acceptable to I

IWB-3512-1.

- 5 Component 10 Weld Description ASME

Code,Section XI Item Number Ultrasonic Examination Coverage Attained (Percentage)

Remarks CPN, Unit 1 Outlet Nozzle to B3.90 71.08 The completed examination was 1-N2B Shell at 338 Degrees limited to 71.08% coverage due to the configuration. The limitation is due to nozzle geometry, vessel saddle effect and adjacent outlet nozzle protrusion. Eight subsurface indications were detected and evaluated as acceptable to IWB-3512-1.

3.1.2 ASME Code Requirement ASME Code,Section XI, Examination Category 8-A, Items 81.11, and 81.12 require essentially 100 percent volumetric examination, as defined by ASME Code,Section XI, Figures IW8-2500-1 and -2, respectively, of the length of RPV circumferential and longitudinal shell welds. ASME Code,Section XI, Items 81.21 and 81.22 require essentially 100 percent volumetric examination, as defined by Figure IW8-2500-3, of the "accessible length" of circumferential and meridional head welds on the RPV. Item 81.30 shell-to-flange weld requires essentially 100 percent volumetric examination, as defined by Figure IW8-2500-4. ASME Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds,Section XI, Division 1" as an alternative approved for use by the NRC in Regulatory Guide (RG) 1.147, Revision 16, Inservice Inspection Code Case Acceptability (RG 1.147, Revision 16), states that a reduction in examination coverage due to part geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, i.e., greater than 90 percent examination coverage is obtained.

ASME Code,Section XI, Examination Category 8-0, Item 83.90, require 100 percent volumetric examination, as defined by ASME Code,Section XI, Figures IWB-2500-7 (a) through (d), as applicable, of full penetration ASME Code, Class 1 nozzle-to-vessel welds on the RPV.

3.1.3 Licensee's ASME Code Relief Request In accordance with 10 CFR 50.55a(g)(5)(iii), the licensee requested relief from the ASME Code-required volumetric examination of ASME Code, Class 1 RPV circumferential, longitudinal shell welds, circumferential and meridional head welds, and nozzle-to-vessel welds listed in Table 3.1.1, reproduced from Table 1 for RR ISIR-33, of the licensee's submittal dated April 8, 2011.

3.1.4 Licensee's Basis for Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds. Due to the design of the reactor vessel, geometric configuration and permanent obstructions limit the volumetric examination coverage of the subject welds.

-6 During the second 10-year RPV examination, the best available technology was utilized in performing the automated ultrasonic examination. The examinations were performed with equipment, procedures, and personnel qualified in accordance with the requirements of ASME Section XI, Appendix VIII, 1995 Edition thru 1996 Addenda as modified by the Performance Demonstration Initiative (POI) program.

Several interferences and vessel geometries prevent full volumetric examination coverage, including the 58 permanent in-core instrument nozzles penetrating the bottom head and six core support lugs permanently attached to the vessel interior limiting the access to the lower head welds. The close proximity of the inlet nozzle and outlet nozzle boss limits the ultrasonic test (UT) scanning of the upper shell longitudinal seam welds. The flange to vessel configuration, specimen slots, and keyways also hinder access. These noted obstructions prevent achieving the essentially 100 percent volumetric examination coverage required by ASME Code. Also, nozzle-to-vessel geometry, vessel saddle effect, and adjacent outlet nozzle protrusion limited access for achieving 100 percent volumetric examination coverage for the nozzle-to-vessel welds.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 [reproduced as Table 3.1].

To increase examination coverage on the subject welds requires a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.

Access to the exterior of the reactor vessel is not practical due to higher radiation exposure and limited access for personnel and equipment caused by the close proximity of building structures/concrete and installed insulation and insulation support members. Greater coverage is achieved via the inside surface and results in less radiation exposure to personnel.

Additionally, some of the same interferences that exist for examination from the inside of the vessel are also present on the outside of the vessel (such as the bottom mounted instrument penetrations). Therefore, I&M does not consider that additional volumetric coverage can be attained without significant additional radiation exposure and additional resources to modify existing structures to allow for access.

Twenty ASME Category B-A welds received examination during the third 10-year lSI Interval.

Ten had coverage greater than 90 percent. There were no indications in the twenty ASME Category B-A welds that were examined.

3.1.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section XI, IWB-2500-1, Category B-P.

Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an

- 7 acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.1.6

NRC Staff Evaluation

For the shell welds listed in Table 3.1, except for dollar plate weld 1-RPV-E and lower head meridional at 30 degrees weld (1-LHM-01), the ASME Code requires essentially 100 percent volumetric examination of pressure retaining welds in the RPV. However, the design configuration of the CNP Units 1 and 2 RPV circumferential and longitudinal shell welds, and circumferential and meridional head welds, limit complete examinations due to adjacent components. In order to effectively increase the examination coverage, the RPV and adjacent components would require design modifications or replacement. This would place a burden on the licensee; thus, examining essentially 100 percent of the ASME Code-required volumes is considered impractical. No indications were identified during the subject examinations.

The design of the RPV limits the examination of the subject welds as shown in technical descriptions and sketches provided by the licensee. The subject RPV welds listed in Table 3.1 above were examined using 4S-degree shear and 4S-degree refracted longitudinal wave scans with equipment, procedures and personnel that were qualified by performance demonstration according to ASME Code,Section XI, Appendix VIII. Examinations of the subject welds were performed with automatic LIT inspection equipment from the inside of the RPV. To increase the coverage from outside of the RPV is not practical due to higher radiation exposure and limited access for personnel and equipment caused by the close proximity of building structures/concrete and installed insulation and insulation support members. The licensee found that performing the subject examinations from inside surface RPV results in less radiation exposure to personnel. In addition there are some of the same interferences that exist for the subject examinations from the inside of the RPV that are also present on the outside of the RPV e.g., the bottom-mounted instrument penetrations. Therefore, the additional volumetric coverage from the outside surface of the RPV can only be attained with significant additional radiation exposure and additional resources to modify existing structures to allow for access. This would not be in keeping with ALARA [as low as reasonably achievable] practices because the relatively high doses would not be offset by quantifiable benefits to public health and safety.

RPV Shell-to-Flange Weld 1-RPV-A Item B1.30 For RPV shell-to-flange weld sections 1 B11-RPV-F1 and 1 B11-RPV-F2, the ASME Code requires essentially 100 percent volumetric examination of pressure retaining welds in the RPV.

However, the design configuration of the shell-to-'nange welds limits complete examinations due to the geometric configuration of the flange-to-shell weld. In order to effectively increase the examination coverage, the RPV and adjacent components would require design modifications or replacement.

The completed examination was limited to 84.4 percent coverage due to the configuration. The limitations are due to flange configuration, specimen slots, and keyways at 0, 90, 180, and 270 degrees. No recordable indications were detected.

- 8 RPV Lower Shell-to-80ttom Head Weld 1-RPV-D, Item 81.11 For RPV lower shell-to-bottom head weld 1-RPV-D, the licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject welds due to their design geometries and by six core support lugs. The completed examination was limited to 82.60 percent coverage due to the configuration. No recordable indications detected by the licensee.

RPV Lower Shell Longitudinal at 60, 180, and 300 Degrees Welds 1-RPV-VC 1, 1-RPV-VC2, and 1-RPV-VC3, Item 81.12 For RPV lower shell longitudinal at 60, 180, and 300 degrees weld 1-RPV-VC1, 1-RPV-VC2, and 1-RPV-VC3, respectively, the licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject welds due to their design geometries and limitation by core support lugs. The completed examinations were limited to 78.29 percent for each of the subject welds. No recordable indications detected by the licensee.

RPV Plate Weld 1-RPV-E and Lower Head Meridional at 30 Degrees Weld 1-LHM-01, Items 81.21 and 81.22 ASME Code,Section XI, Items 81.21 and 81.22, requires that the plate weld 1-RPV-E and lower head meridional at 30 degrees weld 1-LHM-01 be subject to essentially 100 percent volumetric examination of the "accessible length" of the welds. The ASME Code Committee recognizes the limitations of examining these welds and specifically stated in this particular ASME Code requirement to examine the "accessible length" of the welds. The licensee noted in its relief that it did examine the subject welds to the extent practical and that there were no recordable indications detected. Therefore they met the ASME Code requirements and do not require relief from the ASME Code requirements.

3.2 Request for Relief ISIR-34, ASME Code,Section XI. Examination Category 8-8, Item 82.40 Pressure Retaining Welds in Vessels Other Than RPV (CNP, Unit 2) 3.2.1 ASME Code Components ASME Code Class:

Code Class 1 ASME Code,Section XI, Category 8-8, Item Number 82.40, Pressure Retaining Welds in Examination Category:

Vessels Other Than Reactor Vessels CNP Unit 2 Steam Generators (SG) (Primary Side) - Lower Shell-to-Tubesheet Weld STM-24-01 3.2.2 ASME Code Requirement ASME Code,Section XI, Examination Category 8-8, Item 82.40 requires volumetric examination of essentially 100 percent of the weld volume as defined in ASME Code,Section XI, Table IW8-2S00-1 and shown in Figures IW8-2S00-1 and IW8-2S00-6. ASME Code Case N-460, as an alternative approved for use by the NRC in RG 1.147, Revision 16, states that a

- 9 reduction in examination coverage due to part geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, Le., greater than 90 percent examination coverage is obtained.

3.2.3 Licensee's ASME Code Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.

3.2.4 Licensee's Basis for Relief Request (as stated)

The SG tubesheet-to-head weld STM 2-24-01 was limited to 72 percent coverage due to the configuration. Examination coverage was limited due to the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits.

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by ASME Code.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 11.

Increased examination coverage for SG tubesheet-to-head weld STM 2-24-01 requires removal and reinstallation of insulation support ring mounting pads by cutting the mounting pad welds and then reinstalling the mounting pads by welding following completion of the examination.

Additionally, to increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.

The completed examination was limited to 72 percent coverage due to the configuration. Examination coverage was limited due to the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits. One subsurface indication was detected and evaluated as acceptable to ASME Code,Section XI, IWB-3512-1.

3.2.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical given the limitations caused by the geometric configuration and permanent obstructions. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by ASME Code,Section XI, Table IWB-2500-1, Category B-P, Item B2.40.

Table 1 is not included in this safety evaluation (SE) and may be found in the licensee's submittal dated March 6, 2012.

- 10 8ased upon the examination volumes that were obtained with acceptable results, along with the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.2.6 NRC Staff Evaluation The ASME Code requires essentially 100 percent volumetric examination of SG tubesheet-to-head weld STM-24-01. However, for the subject weld at CNP, Unit 2, complete examinations are restricted by the geometric configuration of the welds and scan limitations caused by the proximity of welded pads, nozzles, adjacent piping, hand-hole openings, permanent support brackets, and permanent electrical conduits. The licensee obtained 72 percent of the ASME Code required volume to be completed. The SG weld was examined with manual UT techniques using O-degree longitudinal and 45-and 60-degree shear waves in accordance with applicable requirements of the ASME Code,Section V, Article 4. In order to effectively increase the examination coverage, the subject SG weld would require design modifications or replacement. This would place a burden on the licensee; thus, examining 100 percent of the ASME Code-required volume is considered impractical. One subsurface indication was detected, evaluated, and found acceptable to ASME Code,Section XI, 1WB-3512-1.

The licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject welds due to the deSign configurations of the pressurizer (PZR), SG, and adjacent components. 8ased on the volumetric coverage obtained, along with the examinations completed on other pressure retaining welds in ASME Code,Section XI, Examination Category 8-8, it is reasonable to conclude that if significant service-induced degradation had occurred, evidence of it would have been detected by the examinations that were performed. In addition, the licensee performs VT-2 visual examinations each refueling outage. Furthermore, the staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject components.

3.3 Requests for Relief ISIR-35 Part A. ASME Code. Section XL Examination Category 8-0.

Item 83.110 and Item 3.140, Full Penetration Welds of Nozzles in Vessels other than RPV (CNP. Units 1 and 2) 3.3.1 ASME Code Components ASME Code Class:

Code Class 1 ASME Code Section XI, Table IW8-2500-1 Examination Category 8-0, Full Penetration Welds of Nozzles in Vessels ASME Code,Section XI, Item Numbers 83.110, PZR Nozzle-to-Vessel Welds and, 83.140, SG (Primary Side) - Nozzle Inside Radius Section (IRS)

The component identifications and details are listed in Table 3.3 on Page 11.

- 11 3.3.2 ASME Code Requirement ASME Code,Section XI, Table IWB-2500-1, Examination Category B-D requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figures IWB-2500-7(a) thru (d) as applicable. ASME Code Case N-460, as an alternative approved for use by the NRC in RG 1.147, Revision 16, states that a reduction in examination coverage due to part geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, i.e., greater than 90 percent examination coverage is obtained.

3.3.3 Licensee's ASME Code Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds listed in the Table 1 in the submittal [reproduced as Table 3.3] due to the geometric configuration and permanent obstructions which limit the volumetric examination coverClge of the subject welds.

3.3.4 Licensee's Basis for Relief Request (as stated)

The SG inner radius examinations (STM-12-1-IRS, STM-12-0-IRS, STM-14-1-IRS and STM-14-0-IRS) were limited to 34.9 percent, 36.8 percent, 40.9 percent, and 25 percent coverage, respectively. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area.

Additionally, the PZR nozzle-to-vessel welds (2-RC-26 and 2-RC-27) were each limited to 75 percent coverage. Examination limitations were due to the contour of the weld on the nozzle side, where 50 percent coverage was achieved for both the 45 and 60 degree axial scans.

Table 3.3 Unit Component 10 Weld Description ASME Code Item Number Ultrasonic (UT)

Examination Coverage Attained (Percent)

Remarks 1

STM-14-1-IRS SG Inlet Nozzle IRS 83.140 40.9 The completed examination was limited to 40.9% coverage due to the configuration. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.

1 STM-14-0-IRS SG Outlet Nozzle IRS 83.140 25.0 The completed examination was limited to 25% coverage due to the

- 12 I

ASME Ultrasonic (UT)

Unit Component 10 Weld Code Examination Remarks Description Item Coverage Number Attained (Percent) configuration. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.

1 STM-12-1-IRS SG Inlet Nozzle IRS 83.140 34.9 The completed examination was limited to 34.9% coverage due to the configuration. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.

1 STM-12-0-IRS SG Outlet Nozzle IRS 83.140 36.8 The completed examination was limited to 36.8% coverage due to the configuration. Due to the component geometry, no coverage of the inner radius region can be effectively obtained by scanning from the shell side. No contact could be maintained in the blend radius area. No recordable indications detected.

2 2-RC-26 PZR Upper Head-to-Relief Nozzle 83.110 75.0 The completed examination was limited to 75% coverage due to the configuration. Exam limitations were due to the contour of the weld on the nozzle side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected.

2 2-RC-27 PZR Upper Head-to-Relief Nozzle 83.110 75.0 The completed examination was limited to 75% coverage due to the configuration. Exam limitations were due to the contour of the weld on the nozzle side, where 50% coverage was achieved for both the 45 and 60 degree axial scans. No recordable indications detected.

- 13 These noted obstructions prevent achieving the essentially 100 percent volumetric examination coverage required by ASME Code.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 [reproduced as Table 3.3].

To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design to eliminate the noted obstructions. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.

3.3.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination on the accessible portions of the welds to the maximum extent practical. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section XI, IWB-2500-1, Category B-P.

Based upon the examination volumes that were obtained with acceptable results, along with the visual (VT -2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.3.5

NRC Staff Evaluation

The ASME Code requires 100 percent volumetric examination of ASME Code, Class 1 nozzle-to-vessel welds. However, the design configurations of the subject welds and the proximity of surrounding appurtenances limit access for UT scanning. In order to effectively increase the examination coverage, the nozzle-to-vessel welds would require design modifications and removal of adjacent components. This would place a burden on the licensee; thus, 100 percent ASME Code-required volumetric examinations are considered impractical. The licensee found recordable indications during examinations of the subject welds.

The PZR and SG nozzle-to-vessel welds shown in Table 3.3 are constructed of carbon steel material with stainless steel inside diameter (lD) cladding. The nozzle design geometry limits ASME Code-required UT angle beam examinations to be performed from both the shell side and nozzle side of the welds. As shown on the sketches and technical descriptions included in the licensee's submittals, examinations of the subject PZR and SG nozzle-to-vessel welds have been completed to the extent practical with volumetric coverage ranging from approximately 25 percent to 75 percent (see Table 3.3 above) of the ASME Code-required volumes. The examination volumes typically included the weld and base materials near the inside surface of the weld joint, which are the highest regions of stress, and where one would expect degradation sources to be manifested should they occur. The PZR and SG nozzle-to-vessel weld examinations were performed with UT techniques in accordance with the applicable requirements of the ASME Code Section V, Article 4. The PZR and SG welds were examined using O-degree longitudinal and 45 and 50-degree shear waves. No recordable indications were detected by the licensee during these examinations on the subject welds.

- 14 UT scans were from both the shell side and nozzle inside radius, depending on the geometry and recent studies have found that inspections conducted through carbon steel are equally effective whether the UT waves have only to propagate through the base metal, or have to also propagate through the carbon steel weldment (see Reference 1). Therefore, it is expected that the UT techniques employed by the licensee would detect structurally significant flaws that might occur on either side of the subject welds due to the fine-grained carbon steel microstructures.

The licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject nozzle-to-vessel welds due to their design and adjacent component obstructions. Based on the volumetric coverage obtained for the subject welds, and conSidering the licensee's performance of UT techniques employed to maximize this coverage, it is reasonable to conclude that if significant service-induced degradation had occurred, evidence of it would have been detected by the examinations that were performed.

Furthermore, the staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject components.

3.4 Request for Relief ISI-36 ASME Code,Section XI. Table IWB-2500-1, Category B-F, Item B5.70 Pressure Retaining Dissimilar Metal Welds, Steam Generator Nozzle-to-Safe End Butt Welds 3.4.1 ASME Code Components ASME Code,Section XI, Code Class 1, Table IWB-2500-1 Examination Category B-F, Pressure Retaining Dissimilar Metal Welds Item Numbers B5.70, SG Nozzle-to-Safe End Butt Welds.

The component identifications and details are listed in Table 3.4.

3.4.2 ASME Code Requirement ASME Section XI, 1989 Edition, Examination Category B-F requires volumetric examination of 100 percent of the weld volume as defined in Table IWB-2500-1 and shown in Figure IWB-2500-8.

ASME Code Case N-460, as an alternative approved for use by the NRC in RG 1.147, Revision 16, states that a reduction in examination coverage due to part geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, i.e.,

greater than 90 percent examination coverage is obtained.

3.4.3 Licensee's ASME Code Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.

- 15 Table 3.4 Component Unit Weld 10 Description STM-12-02R 1

Safe End-to-Inlet Nozzle STM-12-03R 1

Safe End-to-Inlet Nozzle STM-14-02R 1

Safe End-to-Inlet Nozzle ASME Code Item Number 85.70 85.70 85.70 UT Examinations Coverage Attained (Percent) 25.72 23.92 25.72 Material Stainless Safe end to Carbon Nozzle with Alloy 52 Weld Stainless Safe end to Carbon Nozzle with Alloy 52 Weld Stainless Safe end to Carbon Nozzle with Alloy 52 Weld Remarks The completed examination was limited to 25.72%

coverage due to the configuration.

The limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.

The completed examination was limited to 23.92%

coverage due to the configuration.

The limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.

The completed examination was limited to 25.72%

coverage due to the configuration.

The limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected.

- 16 Component Unit 10 STM-14-03R 1

STM-22-02 1

STM-22-03 2

Weld Description Safe End-to-Inlet Nozzle Elbow-to-Inlet Nozzle Elbow-to-I n let Nozzle ASME Code Item Number 85.70 85.70 85.70 UT Examinations Coverage Attained (Percent) 23.9 19.5 19.5 Material Remarks Stainless The completed Safe end examination was to Carbon limited to 23.9%

Nozzle coverage due to with Alloy the configuration.

52 Weld The limited coverage of this weld is due to the configuration of the taper transition of the safe end. No recordable indications detected Cast The completed Stainless examination was Steel limited to 19.5%

Elbow to coverage due to the Stainless configuration.

Safe End Limitations were with Alloy encountered due 308L Weld the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material.

No relevant indications detected.

Cast The completed Stainless examination was Steel limited to 19.5%

Elbow to coverage due to the Stainless configuration.

Safe End Limitations were with Alloy encountered due 308L Weld the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material.

No relevant indications detected.

I

- 17 Component 10 Unit Weld Description ASME Code Item Number UT Examinations Coverage Attained (Percent)

Material Remarks STM-23-02 2

Elbow-to-I nlet Nozzle 85.70 19.5 Cast Stainless Steel Elbow to Stainless Safe End with Alloy 308L Weld The completed examination was limited to 19.5%

coverage due to the configuration.

Limitations were encountered due to the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material.

No relevant indications detected.

STM-23-03 2

Outlet Nozzle-to-Elbow 85.70 19.5 Cast Stainless Steel Elbow to Stainless Safe End with Alloy 308L Weld The completed examination was limited to 19.5%

coverage due to the configuration.

Limitations were encountered due to the contour of the weld along with depressions on the nozzle side of the weld and the CASS Elbow material. No relevant indications detected.

3.4.4 Licensee's Basis for Relief Request (as stated)

The SG nozzle-to-safe end examinations STM-12-02R, STM-12-03R, STM-14-02R and STM-14-03R, were limited to 25.72 percent, 23.92 percent, 25.72 percent, and 23.9 percent coverage, respectively, due to the component geometry. Coverage was limited due to tapers, weld contours, and depressions on some of the nozzles.

The safe end-to-elbow examinations STM-22-02, STM-22-03, STM-23-02 and STM-23-03, were limited to 19.5 percent, 19.5 percent, 19.5 percent, and 19.5 percent coverage, respectively, due to

- 18 limitations encountered with the contour of the weld along with depressions on the nozzle side of the weld and the CAST Elbow material. These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by ASME Code. The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 3.4.

ASME Code Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume. For the welds listed in Table 1 of the submittal [reproduced as Table 3.4], the examinations were performed after the 10 CFR 50.55a mandatory implementation date of November 22,2002, for ASME Code,Section XI, Appendix VIII. The ASME Code Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume.

For the welds listed in Table 1 [reproduced as Table 3.4, the examinations were performed after the 10 CFR 50.55a mandatory implementation date of November 22,2002, for ASME Code,Section XI, Appendix VIII. The ASME Code coverage percentages provided reflect what is currently allowed by qualified ASME Code,Section XI, Appendix VIII, techniques. ASME Code,Section XI, Appendix VIII, qualified POI procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the POI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry as qualified through POI. I&M has used the best available techniques to examine the subject piping welds. To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. No alternative testing is proposed at this time. I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the Code. I&M also performed surface examinations of 100 percent of the required area without limitations.

Additionally, for the welds consisting of Cast Austenitic Stainless Steel (CASS) elbow material (STM-22-02, STM-22-03, STM-23-02 and STM-23-03), there are currently no Appendix VIII POI qualified procedures to inspect CASS materials. The SG Inlet and Outlet nozzle configuration includes an austenitic stainless steel safe-end welded to a cast austenitic stainless steel elbow. The Appendix VIII procedure qualified for the examination of austenitic stainless steel welds from the outside diameter (00) surface was used to perform a best effort examination of the CASS elbow material.

To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure, and impact to plant equipment.

3.4.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination on the accessible portions of the subject welds to the maximum extent practical. Each weld also received a surface examination without limitations. Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by ASME Code,Section XI, IWB-2500-1, Category B-P.

- 19 8ased upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected.

Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.4.6

NRC Staff Evaluation

The ASME Code requires essentially 100 percent volumetric and surface examinations for the ASME Code,Section XI, Examination Category 8-F, Item Number 85.70. dissimilar metal pressure retaining welds. However, complete volumetric examinations were restricted by several factors, including weld geometry and the cast stainless steel elbows that are difficult to inspect.

These conditions prevented the licensee obtaining full volumetric examinations from both sides of the weld. To gain access for improved examination the welds would require design modifications or removal and replacement of components. Imposition of this requirement would place a burden on the licensee; therefore, the ASME Code-required 100 percent volumetric examinations are impractical.

For the subject pipe welds, volumetric examinations were conducted using manual techniques qualified in accordance with performance demonstration requirements listed in ASME Code,Section XI, Appendix VIII. using both shear and L-wave transducers. The L-wave method is believed capable of detecting planar 10 surface-breaking flaws on the far-side of wrought stainless steel welds. Studies (see References 2 and 3) reported in the technical literature recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds. The welds were inspected with 35 and 45 degree shear waves and 45 and 60 degree longitudinal waves.

Various scan limitations in the axial and circumferential directions were caused by the configuration of the welds and the cast stainless elbow material. As shown on the sketches and technical descriptions2 included in the licensee's submittal, examinations of the subject welds have been performed to the extent practical with the licensee obtaining volumetric coverage ranging from 19.5 to 25.72 percent (see Table 3.4 above) in the required areas. An important factor in this evaluation is that significant supplementary non-code coverage was obtained on the welds in the areas in the middle third, and in some cases the upper third, of the weld.

While primary water stress corrosion cracking (PWSCC) is often an issue with dissimilar metal welds. the nickel alloy used in the safe end to nozzle welds is alloy 52, which is resistant to PWSCC. For the Alloy 52 and 308L welds the only identified degradation mechanism is thermal fatigue, which progresses relatively slowly. As the cracks would propagate relatively slowly the non-code coverage is very useful in determining if there is significant degradation in these welds.

The licensee completed the ASME Code-required surface PT [penetrant test] examinations on the subject welds, with no limitations. No relevant indications were observed during any of the ultrasonic and surface examinations.

2 The licensee's sketches and technical descriptions are not included in this SE.

- 20 The licensee has shown that it is impractical to meet the ASME Code-required volumetric and surface examination coverage for the subject welds due to the design of the welds and proximity of other components. Considering the volumetric coverage obtained and the resistant materials, it is reasonable to conclude that if significant service-induced degradation had occurred in the subject welds, evidence of it would have been detected. Furthermore, the NRC staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject welds.

3.5 Request for Relief ISIR-37. ASME Code.Section XI. Table IW8-2500-1. Examination Category 8-J. Items 89.11 Pressure Retaining Welds in Piping Nominal Pipe Size (NPS) 4 Inch and Larger, Circumferential Welds and ASME Code,Section XI. Table IW8-2500-1, Examination Category 8-J, Item 89.31 8ranch Pipe Connection Welds NPS 4 Inch or Larger 3.5.1 ASME Code Components ASME Code Class:

Code Class 1 ASME Code,Section XI, Examination Category 8-J Items Numbers 89.11 and 89.31 Pressure Retaining Welds in Piping NPS 4-inch and Larger Circumferential Welds and 8ranch Pipe Connection Welds, NPS 4-inch or Larger The component identifications and details are listed in Table 3.5.

3.5.2 ASME Code Requirement ASME Code Section XI, Table IW8-2500-1, Examination Category 8-J, Items Numbers 89.11 and 89.31 requires volumetric examination of 100 percent of the weld volume as defined in Table IW8-2500-1 and shown in Figures IW8-2500-8, or IW8-2500-9, -10 or -11. ASME Code Case N-460, as an alternative approved for use by the NRC in RG 1.147, Revision 16, states that a reduction in examination coverage due to part geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, i.e., greater than 90 percent examination coverage is obtained.

3.5.3 Licensee's ASME Code Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.

3.5.4 Licensee's 8asis for Relief Request (as stated)

Due to the component geometry coverage was limited due to tapers, bevels, weld contours, and joint configurations.

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.

- 21 The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 of the submittal [reproduced as Table 3.5].

During UT examination of the piping welds listed in Table 1 [reproduced as Table 3.5] of this relief request, 100 percent coverage of the required examination volume could not be obtained. Class 1 piping and components are often designed with welded joints such as nozzle-to-pipe, pipe-to-valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume.

For the welds listed in Table 3.5, the examinations were performed using Appendix VIII of Section XI as modified by the PDI program. The provided code coverage percentages reflect what is allowed by qualified Appendix VIII techniques. Appendix VIII qualified PDI procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the PDI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For all the cornponents listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry, but this portion ofthe examination is not included in the reported coverage for welds examined under PDI and Appendix VIII rules. I&M has used the best available techniques to examine the subject piping welds. To improve upon these examination coverage percentages, modification and/or replacement of the component would be required. No alternative testing is proposed at this time.

I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the ASME Code.

Table 3.5 Component ID Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 1-RH-28-05F 1

Pipe-to-Pipe 89.11 50.0 80th Sides are 316 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The config u ration prevents examination on the penetration side due to the bevel and the contour of the inside diameter (ID) and outside diameter (OD). No relevant indications detected.

1

- 22 I

ASME UT Component Unit Weld Code Examination Material Remarks ID Description Item Coverage Number (Percent) 1-SI-22-1SF Pipe-to-Valve B9.11 50.0 Both The completed Sides are examination was 316 limited to 50%

Stainless coverage due to the Steel configuration. The coverage limitation was due to the OD bevel configuration on the valve side of the weld. No relevant indications detected 1-SI-23-17F 1

Pipe-to-Valve B9.11 50.0 Both The completed Sides are examination was 316 limited to 50%

Stainless coverage due to the Steel configuration. The coverage limitation was due to the OD bevel configuration on the valve side of the weld. No relevant indications detected.

1-RC-5-01F B9,11 1

Branch-to-Pipe 50.0 316 The completed Stainless examination was Steel Pipe limited to 50%

to SA 351 coverage due to the CFSM configuration. The Branch exam limitation was due to the proximity of the branch connection to the branch side weld. No relevant indications detected.

1-SI-33-23S B9,11 50,0 1

Tee-to-Pipe 316 The completed Stainless examination was Steel Pipe limited to 50%

to SA-403 coverage due to the Grade WP configuration. The 316 Tee configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

I i

- 23 Component 10 Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 2-RC-22-01 2

Safe End-to-Elbow 89.11 65.0 316 Stainless Steel Pipe to SA 351 CF8M Safe End The completed examination was limited to 65%

coverage due to the configuration. The configuration prevents examination due to the geometry of the safe end. No relevant indications detected.

2-RC-28-23 2

T ee-to-Pipe 89.11 66.7 80th Sides are 316 Stainless Steel The completed examination was limited to 66.7%

coverage due to the configuration. The config u ration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

2-51-56-19 2

Tee-to-Pipe 89.11 50.0 80th Sides are 316 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

2-RH-33-01 2

8ranch-to-Pipe 89.11 50.0 80th Sides are 316 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

- 24 Component ID Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 2-RC-17-0SN 2

Branch-to-Pipe B9.31 34.0 Cast Austenitic Stainless Steel SA-351 Grade CFSM Pipe to WP316 Stainless steel Branch The completed examination was limited to 34%

coverage due to the configuration.

Limitations were based on the joint configuration. No axial scans were performed on the downstream side of the weld along with no circumferential scans on the branch connection weld due to the contour of the weld. In addition, circumferential scans could only be performed on the branch connection base material. No relevant indications detected.

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by the ASME Code.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 of the submittal [reproduced as Table 3.5].

Ouring UT examination of the piping welds listed in Table 1 [reproduced as Table 3.5] ofthis relief request, 100 percent coverage of the required examination volume could not be obtained. Class 1 piping and components are otten designed with welded joints such as nozzle-to-pipe, pipe-to-valve, and pipe-to-pump which can physically obstruct a large portion of the required examination volume.

For the welds listed in Table 3.5, the examinations were performed using Appendix VIII of Section XI as modified by the POI program. The code coverage percentages provided reflect what is allowed by qualified Appendix VIII techniques. Appendix VIII qualified POI procedures have demonstrated that sound beams may potentially be attenuated and distorted when required to pass through austenitic weld metal. However, the POI qualified methods employ the best available technology for maximizing examination coverage of these types of welds. For all the components listed in this relief request, examination was extended to the far side of the weld to the extent permitted by geometry, but this portion of the examination is not included in the reported coverage for welds examined under POI and AppendixVIII rules. I&M has used the best available techniques to examine the subject piping welds. To improve upon these examination coverage percentages, modification and/or

- 25 replacement of the component would be required. No alternative testing is proposed at this time.

I&M has examined the subject welds to the extent practical and will continue to perform pressure testing on the subject welds as required by the ASME Code.

To increase examination coverage on the subject weld would require a significant design modification or replacement of components with a different design or material to eliminate the noted obstructions or material limitations. This is impractical due to the cost, additional radiation exposure and impact to plant equipment.

3.5.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination on the accessible portions of the welds to the maximum extent practical. Each weld also received a surface examination without limitations.

Additionally, a visual examination (VT-2) is performed at the end of each refueling outage during the system leakage tests as required by Section XI, IWB-2500-1, Category B-P.

Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each refueling outage, it is reasonable to conclude that service induced degradation would be detected if present.

Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.5.6

NRC Staff Evaluation

ASME Code,Section XI, requires essentially 100 percent volumetric and surface examinations for the Examination Category B-J, Item Number B9.11, pressure retaining welds described in Table 3.5. Complete volumetric examinations were restricted by several factors, including pipe fitting, weld crown, and branch connection configurations. These conditions preclude the licensee obtaining full volumetric examinations from both sides of the weld. To gain access for examination, the welds would require design modifications. Imposition of this requirement would place a burden on the licensee; therefore, the ASME Code-required 100 percent volumetric examinations are impractical.

For the subject pipe welds, volumetric examinations were conducted using manual techniques qualified in accordance with performance demonstration requirements listed in ASME Code,Section XI, Appendix VIII, using both shear and L-wave transducers. The L-wave method is believed capable of detecting planar 10 surface-breaking flaws on the far-side of wrought stainless steel welds. Studies (References 2 and 3) reported in the technical literature recommend the use of both shear and L-waves to obtain the best detection results, with minimum false calls, in austenitic welds.

VariolJs scan limitations in the axial and circumferential directions were caused br the configuration of the welds. As shown on the sketches and technical descriptions included in the licensee's submittal, examinations of the subject welds have been performed to the extent practical with the licensee obtaining volumetric coverage ranging from 34 to 66.7 percent (see 3

The licensee's sketches and technical descriptions are not included in this SE.

- 26 Table 3.5 above) in the required areas. The inspections were carried out using 45 and 60 degree shear waves and 60 degree longitudinal waves.

The welds in ISIR-37 are not affected by stress corrosion cracking, and the most likely degradation mechanism is thermal fatigue. Thermal fatigue is a relatively slow process. Also, the coverage maps show that while the welds were not inspected to 100 percent of the code volume, the inspections for circumferential flaws does insonify most of the required volume.

The licensee completed the ASME Code-required surface PT examinations on the subject welds, with no limitations. No relevant indications were observed during any of the ultrasonic and surface examinations.

The licensee has shown that it is impractical to meet the ASME Code-required volumetric and surface examination coverage for the subject welds due to the design of the welds and proximity of other components. Considering the volumetric coverage obtained it is reasonable to conclude that if significant service-induced degradation had occurred in the subject welds, evidence of it would have been detected. Furthermore, the NRC staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject welds.

3.6 Request for Relief ISIR-3a, ASME Code,Section XI. Table IWC-2500-1, Examination Category CA Items C1.10, C1.20, C1.30 Pressure Retaining Welds in Vessels Other Than The RVP (CNP, Unit 2) 3.6.1 ASME Code Components ASME Code Class:

Code Class 2 ASME Code,Section XI, Table IWB-2500-1 Examination Category C-A Pressure Retaining Welds in Pressure Vessels Item Numbers C1.10, Shell Circumferential Welds and C1.20, Head Circumferential Welds C1.30, Tubesheet-to-Shell Weld The component identifications and details are listed in Table 3.6.

3.6.2 ASME Code Requirement ASME Code,Section XI, IWB-2500-1, Examination Category C-A requires volumetric examination of essentially 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figures IWC-2500-1 or IWC-2500-2 as applicable. ASME Code Case N-460, as an alternative approved for use by the NRC in RG 1.147, Revision 16, states that a reduction in examination coverage due in part to geometry or interference for any Class 1 and 2 weld is acceptable provided that the reduction is less than 10 percent, i.e., greater than 90 percent examination coverage is obtained.

- 27 Table 3.6 Component 10 Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Remarks CNP, Unit 2 West Containment Spray System Heat Exchanger Shell-to-Flange Weld W-CTSHEX-2 Shell-to-Flange C1.10 48.1 The completed examination was limited to 48.1 % coverage due to the configuration. The examination was single sided due to the proximity of the flange and associated bolting. Exam limitation on the accessible side was due to the inlet and outlet nozzles restricting access for an 11" area of the weld. No relevant indications detected.

CNP, Unit 2 Boron Injection Tank Safety Injection Emergency Core Cooling System Shell-to-Lower Head Weld 2-BIT-A Shell-to-Lower Head C1.20 80.5 The completed examination was limited to 80.5% coverage due to the configuration. The examination limitation was due to four leg supports located along the weld from 0 degrees at 18"-26",62"-70",99"-107", and 142"-150". No relevant indications detected.

CNP, Unit 2 Tube C1.30 85.0 The completed examination was

1. 4 SG Tube Sheet-to-Stub limited to 85% coverage due to Sheet-to-Stub Barrel the configuration. Examination Barrel Weld coverage was limited due to the STM-24-04 proximity of welded pads, nozzles, adjacent piping, hand hold openings, permanent support brackets and permanent electrical conduits. No relevant indications detected.

3.6.3 Licensee's ASME Code Relief Request (as stated)

Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject weld due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.

3.6.4 Licensee's Basis for Relief Request (as stated)

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 [reproduced as Table 3.6].

- 28 To increase examination coverage on the subject welds requires removal of the permanently welded pads, supports, electrical supports, adjacent piping and nozzles or replacement of the heat exchanger with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment.

3.6.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.

Based upon the examination volumes that were attained with acceptable results along with the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.6.6

NRC Staff Evaluation

The ASME Code requires essentially 100 percent volumetric examination of ASME Code, Class 2 vessel circumferential head and shell welds. However, for the subject welds on the CNP, Unit 2 west containment spray system heat exchanger shell-to-flange weld W-CTSHEX-2, boron injection tank safety injection emergency core cooling system shell-to-Iower head weld 2-BIT -A, and #4 SG tube sheet-to-stub barrel weld STM-24-04 complete examinations are restricted by the design configuration and the proximity of adjacent appurtenances. Achieving greater coverage on these welds would require that these subject component welds be redesigned and modified.

This would place a burden on the licensee; therefore, the ASME Code examinations are considered impractical.

As shown on the sketches and technical descriptions included in the licensee's submittal, examinations of the CNP, Unit 2 west containment spray system heat exchanger shell-to-flange weld (W-CTSHEX-2) is constructed of carbon steel with stainless steel cladding. The subject examinations were performed using 0 degree longitudinal wave, 45 degree shear wave, and 60 degree longitudinal wave scans to achieve limited coverage to the extent practical with an aggregate volumetric coverage of 48.1 percent of the ASME Code-required volume. The examination was single sided due to the proximity of the flange and its associated bolting limiting the examinations. Exam limitation on the accessible side was due to the inlet and outlet nozzles restricting access for an 11" area of the weld. The licensee performed UT examinations on the west containment spray system heat exchanger shell-to-flange weld W-CTSHEX-2 using ASME Code,Section XI, Appendix VII procedures.

The licensee performed manual UT examinations using ASME Code,Section V, Article 4, on the CNP, Unit 2 boron injection tank safety injection emergency core cooling' system shell-to-Iower head weld 2-BIT-A and is constructed of carbon steel with stainless steel cladding. The UT examinations conducted by the licensee included 45 degree longitudinal, 45 degree shear wave

- 29 and 60 degree shear wave scan angles. The examination was limited to 80.5 percent coverage due to the configuration of the subject component. The examination limitation was due to four leg supports located along the weld from 0 degrees at 18"-26", 62"-70",99"-107", and 142/1-150".

The licensee performed manual UT examinations using ASME Code,Section V, Article 4, on the CNP, Unit 2 #4 SG tube sheet-to-stub barrel weld STM-24-04 and is constructed of carbon steel with stainless steel cladding. The UT examinations conducted by the licensee included 45 degree shear wave and 60 degree shear wave scan angles. The examinations were limited to 85 percent of the ASME Code required volume due to the configuration of the subject component. The examinations were limited due to the proximity of welded pads, nozzles, adjacent piping, hand hold openings, permanent support brackets and permanent electrical conduits.

The subject Class 2 pressure retaining weld volumetric examinations were conducted in accordance with the applicable requirements of the ASME Code at the time of the examinations.

No recordable flaw indications were observed by the licensee during any of the subject exam inations.

The licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject welds due to geometry configuration and interference from surrounding components. Based on the volumetric coverage obtained, and that the licensee performs a VT-2 visual examination during each inspection period during the system leakage tests as required by ASME Code,Section XI, Table IWC-2500-1, Category C-H, it is reasonable to conclude that, if significant service-induced degradation had occurred, evidence of it would have been detected by the examinations that were performed. Furthermore, the staff determined that the examinations performed to the extent practical on the subject welds provide reasonable assurance of structural integrity of the subject welds.

3.7 Request for Relief ISIR-39, ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B, Pressure Retaining Nozzle Welds in Vessels, Item Number C2.21,

Nozzles Without Reinforcing Plate in Vessels> 'Y:!-inch Nominal Thickness, Nozzle to Shell (or Head) Weld 3.7.1 ASME Code Components ASME Code Class:

Code Class 2 ASME Code,Section XI, IWC-2500-1, Examination Category C-B, Pressure Retaining Nozzle Welds in Vessels, Item Number C2.21, Nozzles Without Reinforcing Plate in Vessels> 'Y:! inch Nominal Thickness, Nozzle to Shell (or Head) Weld The component identifications and details are listed in Table 3.7.

3.7.2 ASME Code Requirement ASME Code,Section XI, Table IWC-2500-1, Examination Category C-B requires volumetric examination of 100 percent of the weld volume and surface examination as defined in Table IWC-2500-1 and shown in Figures IWC-2500-4{a) or IWC-2500-4{b) as applicable. The

- 30 alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 16, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.

3.7.3 Licensee's ASME Code Relief Request Pursuant to 10 CFR 50.55a(g)(5)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limits the volumetric examination coverage of the subject welds.

Table 3.7 Component 10 Weld Description ASMECode Item Number UT Examination Coverage (Percent)

Remarks CNP, Unit 1 #4 SG Feed Water Nozzle-to-Shell Weld STM-14-FWN Nozzle-to-Shell C2.21 46.5 The completed examination was limited to 46.5% coverage due to the configuration. The coverage limitation was due to the proximity of insulation and a metal strap at top-dead-center and at bottom-dead-center due to the shell weld. No relevant indications detected.

3.7.4 Licensee's Basis for Relief Request (as stated)

Due to the component geometry, coverage was limited due to tapers, bevels, weld contours, and joint configurations.

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by code.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 [reproduced as Table 3.7]. To increase examination coverage on the subject welds requires removal of significant portions of insulation and its supporting elements and redesign of the blend radius of the nozzle to shell weld with a design that would allow for complete examination coverage of the subject weld. This option to meet the 100 percent code examination requirement is considered impractical due to the cost, increased radiation exposure and impact to plant equipment.

3.7.5 Licensee's Proposed Alternative Examination (as stated)

The subject welds received a volumetric examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a surface examination without any limitations was performed along with a visual (VT-2) examination that is performed during

- 31 each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.

Based upon the examination volumes that were attained along with acceptable results and the acceptable surface examination that was performed and the visual (VT -2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.7.6

NRC Staff Evaluation

The ASME Code requires 100 percent volumetric and surface examination of Code Class 2 nozzle-to-shell (or head) welds. However, for CNP, Unit 1, SG nozzle-to-shell weld STM-14-FWN, a complete examination is limited due to the proximity of insulation and a metal strap at top-dead-center and at bottom-dead-center of the nozzle. In order to achieve greater volumetric coverage, the nozzle and vessel would have to be redesigned and modified. This would place a burden on the licensee, therefore the ASME Code volumetric examination is considered impractical.

As shown on the sketches and technical descriptions included in the licensee's submittal, examination of the carbon steel CNP, Unit 1, SG nozzle-to-shell weld STM-14-FWN was performed to the extent practical, with the licensee obtaining 46.5 percent of the required examination volume, including O-degree longitudinal, and 45-and 60-degree shear wave scans from the shell side of the weld. The SG is fabricated of carbon steel material with a nominal thickness of 3.7-inches. The manual UT examinations were performed in accordance with the applicable requirements of the ASME Code,Section V, Article 4, at the time of the examinations.

The licensee found two indications that were far from recordable and were noted for future information only. Although UT scans were primarily limited to the shell side only, recent studies have found that inspections conducted through carbon steel are equally effective whether the UT waves have only to propagate through the base metal, or have to also propagate through the carbon steel weldment. Therefore, due to the fine':'grained carbon steel microstructures, it is expected that the UT techniques employed would have detected structurally significant flaws that may have occurred on either side of the subject welds.

The licensee performed the ASME Code required surface examination and no recordable indications were found. In addition, the licensee performed VT-2 visual examinations that are performed during each inspection period during the system leakage tests as required by ASME Code,Section XI, Table IWC-2500-1, Category C-H. The licensee has shown that it is impractical to meet the ASME Code-required 100 percent volumetric examination coverage for the subject nozzle-to-shell weld due to the nozzle design configuration. However, based on the volumetric coverage obtained, surface examination and VT-2 leakage test performed it is reasonable to conclude that, if significant service-induced degradation had occurred, evidence of it would be have been detected by the examinations performed. Furthermore, the staff determined that the examinations performed to the extent practical on the subject welds provide reasonable assurance of structural integrity of the subject welds.

- 32 3.8 Request for Relief ISIR-40, ASME Code,Section XI, Table IWC-2S00-1, Examination Cateqory C-C, Integral Attachments for Vessels, Piping, Pumps, and Valves, Items C3.20 Piping and C3.40 Valves 3.8.1 ASME Code Components ASME Code Class:

Code Class 2 ASME Code,Section XI, Table IWC-2S00-1, Examination Category C-C Integral Attachments for Vessels, Piping, Pumps and Valves Item Numbers 'C3.20, Pumps, Integrally Welded Attachments and C3.40 Valves, Integrally Welded Attachments.

The component identifications and details are listed in Table 3.8.

Table 3.8 Component ID Unit Weld Description ASME Code Item Number PT Examination Coverage (Percent)

Remarks 1-MS-6-11 S-PS 1

Integrally Welded Pipe Attachment C3.20 64 The completed examination was limited to 64% due to configuration. Base metal examinations were limited due to inner and outer cooler interference. No relevant indications detected.

MSIV-MRV-230-S2 1

Integrally Welded Support C3.40 83.3 The completed examination was limited to 83.3%

coverage due to the configuration. The limitation on the extent of the coverage for the bottom horizontal attachment weld was based on the orientation of the attached support in relation to the weld. No relevant indications detected.

3.8.2 ASME Code Requirement ASME Section XI, 1989 Edition, Examination Category C-C requires surface examination of 100 percent of the weld as defined in Table IWC-2S00-1 and shown in Figure IWC-2S00-S. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 16, allows credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required area has been examined.

- 33 3.8.3 Licensee's ASME Code Relief Request Pursuant to 10 CFR SO. SSa{g)(S)(iii), relief is requested from the essentially 100 percent surface examination coverage requirement for the subject weld due to the permanently attached support orientation and permanently embedded bolting obstructions which limits the surface examination coverage of the subject weld.

These noted obstructions prevent achieving the essentially 100 percent volume examination coverage required by ASME Code.

3.8.4 Licensee's Basis for Relief Request (as stated)

To increase the examination coverage on the subject weld requires removal of the permanent structural steel support member by physically cutting the support members apart and replacing the support members by re-welding following the completion of the surface examination. Removal of the permanently welded support members is considered to be impractical based due to increased cost, potential for increased radiation exposure, and impact to plant equipment.

3.8.S Licensee's Proposed Alternative Examination (as stated)

The subject welds received a surface examination utilizing the best available techniques on the accessible portions of welds to the extent practical. Additionally, a visual (VT-2) examination is performed during each inspection period during the system leakage tests as required by Section XI, Table IWC-2S00-1, Category C-H.

Based upon the examination volumes that were attained along with acceptable results and the acceptable visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected. Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.8.6

NRC Staff Evaluation

ASME Section XI, 1989 Edition, Examination Category C-C, Item Numbers C3.20 and C3.40, require surface examination of 100 percent of the, weld as defined in Table IWC-2S00-1 and shown in Figure IWC-2S00-S. Achieving this level of coverage was blocked by the presence of nearby components and weld configurations. In order to achieve greater volumetric coverage the components would have to be redesigned and modified. This would place a burden on the licensee, therefore the ASME C.ode volumetric examination is considered impractical.

As shown on the sketches and technical descriptions included in the licensee's submittal, examination of the welds was performed to the extent practical, with the licensee obtaining 64 percent coverage on 1-MS-6-11 S-PS and 83.3 percent on MSIV-MRV-230-S2. Due to the coverage obtained and the lack of an active degradation mechanism, it is expected that the penetrant techniques employed would have detected structurally significant flaws that may have occurred on either side of the subject welds.

- 34 In addition to the surface tests, the licensee performed the vr-2 visual examinations that are performed during each inspection period during the system leakage tests as required by ASME Code,Section XI, Table IWC-2500-1, Category C-H.

The licensee has shown that it is impractical to meet the ASME Code-required 100 percent surface examination coverage for the subject welds due to the design configurations. However, based on the surface coverage obtained and vr-2 leakage test performed it is reasonable to conclude that, if significant service-induced degradation had occurred, evidence of it would be have been detected by the examinations performed. Furthermore, the. staff determined that the examinations performed to the extent practical on the subject welds provide reasonable assurance of structural integrity of the subject welds.

3.9 Request for Relief ISIR-41, ASME Code,Section XI. Table IWC-2500-1, Examination Category C-F-1, Pressure Retaining Welds In Austenitic Stainless Steel or High Alloy Piping, Items C5.11 and C5.21 3.9.1 ASME Code Components ASME Code Class:

Code Class 2 ASME Code,Section XI, Table IWC-2500-1, Examination Category C-F-1, Item Numbers C5.11, Piping Welds> 3/8 inch Nominal Wall Thickness for Piping >NPS 4, Circumferential Weld, Item C5.21, Piping Welds> 1/5 inch Nominal Wall Thickness for Piping >NPS 2 and < NPS 4, Circumferential Weld The component identifications and details are listed in Table 3.9.

Table 3.9 Component Unit Weld Description ASME UT Material Remarks 10 Code Examination Item Coverage Number (Percent) 1-CTS-2-18 F

1 Pipe-to-Flange C5.11 50.0 Type 304 Stainless The completed examination was Steel limited to 50%

coverage due to the configuration. The flange side is limited by the 0.0. contour and flange bolting.

No relevant indications detected.

- 35 Component Unit Weld Description ASME UT Material Remarks 10 Code Examination Item Coverage Number (Percent) 1-ISI-2-42S 1

Pipe-to-Pump Casing CS.11 SO.O Type 316 Stainless Steel The completed examination was limited to SO%

coverage due to the configuration. The configuration prevents examination from the pump side due to its severe taper and the proximity of the pump casing to the weld. No relevant indications detected.

1-RH-27-0S S

1 Pipe-to-Elbow CS.11 78.0 Stainless Steel The completed examination was limited to 78%

coverage due to the configuration. The configuration prevents examination due to the welds location inside of the box restraint surrounding the pipe.

No relevant indications detected.

1-SI-24-06F 1

Pipe-to-Tee CS.11 SO.O Type 316 Stainless Steel The completed examination was limited to SO%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

- 36 Component Unit Weld Description ASME UT Material Remarks 10 Code Examination Item Coverage Number (Percent) 1-SI-30-08F 1

Valve-to-Pipe C5.11 50.0 Type 316 Stainless The completed examination was Steel limited to 50%

coverage due to the configuration. The examination limitation is caused by the 00 bevel on the valve, which is in proximity to the weld toe on the valve side.

No relevant indications detected.

1-SI-34-11F 1

Elbow-to-Valve C5.11 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. Full coverage was not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.

2-CTS-13-0 4F 2

Pipe-to-Valve C5.11 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.

- 37 Component Unit Weld Description ASME UT Material Remarks ID Examination Item Code Coverage Number (Percent) 1-SI-11A-01 1

Flange-to-Elbow C5.21 50.0 Type 304 The completed S

Stainless examination was Steel limited to 50%

coverage due to the configuration. The configuration of the reducing elbow to flange leads to a limited examination based on the taper of the flange face and its proximity to the weld. No relevant indications detected.

1-SI-11-01S 1

Flange-to-Elbow C5.21 50.0 Type 304 The completed Stainless examination was Steel limited to 50%

coverage due to the configuration. The configuration of the elbow to, flange leads to a limited examination based on the taper of the flange face and its proximity to the weld. No relevant I

indications detected.

- 38 Component Unit Weld Description ASME Material UT Remarks 10 Code Examination Item Coverage Number (Percent) 1-SI-11-0SF 1

CS.21 Pipe-to-Valve 49.0 Type 304 The completed Stainless examination was Steel limited to 49%

coverage due to the configuration. The configuration prevents examination from the valve side due to its severe taper and the close proximity of the valve. A portion of the pipe side is obstructed due to the proximity of the integrally welded pipe support. No relevant indications detected.

1-SI-74-01 F 1

Penetration-to CS.21 Type 316 SO.O The completed Elbow Stainless examination was Steel limited to SO%

coverage due to the configuration. The configuration prevents examination from the penetration side due to the OD surface contour and the proximity of the penetration. No relevant indications detected.

I I

- 39 Component Unit Weld Description ASME UT Material Remarks 10 Code Examination Item Coverage Number (Percent) 2-SI-42-01 S 2

Flange-to-Elbow CS.21 SO.O Type 304 Stainless Steel The completed examination was limited to SO%

coverage due to the configuration. The configuration prevents examination from the flange side due to its severe taper and close proximity of the flange taper to the weld. No relevant indications detected.

2-IS-42-03F 2

Pipe-to-Valve CS.21 46.S Type 304.

Stainless Steel The completed examination was limited to 46.S%

coverage due to the configuration.

The configuration prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. Additionally, a portion of the examination area was obstructed due to a branch connection in the piping. No relevant indications detected.

- 40 Component 10 Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 2-SI-73-02S 2

Elbow-to-Pipe CS.21 SO.O Stainless Steel The completed examination was limited to SO%

coverage due to the configuration. The configuration prevents examination from the elbow side due to its severe taper and close proximity of the elbow to the weld. No relevant indications detected.

2-SI-81-01 F 2

Valve-to-Elbow CS.21 SO.O Stainless Steel The completed examination was limited to SO%

coverage due to the configuration. The configuration prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.

3.9.2 ASME Code Requirement ASME Code,Section XI, Table IWC-2S00-1, Examination Category C-F-1 requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2S00-1 and shown in Figure IWC-2S00-7. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 16, allows credit for essentially 100 percent coverage of the welds provided greater than 90 percent of the required volume has been examined.

The regulation in 10 CFR SO.SSa(b)(2)(xv)(A), requires the following examination coverage criteria when applying Supplement 2 to Appendix VIII:

(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available.

- 41 (2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not possible on austenitic welds, full coverage credit from a single side may be claimed only after completing a successful single sided Appendix VIII demonstration using flaws on the opposite side of the weld.

The regulation in 10 CFR SO.SSa(b)(2)(xvi)(B), requires that examinations performed from one side of a ferritic or stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of ASME Code,Section XI, Appendix VIII as modified by this paragraph and 10 CFR SO. SSa(b)(2)(xv)(A).

3.9.3 Licensee's ASME Code Relief Request Pursuant to 10 CFR SO.SSa(g)(S)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.

3.9.4 Licensee's Basis for Relief Request (as stated)

There are currently no POI qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications.

POI Performance Demonstration Qualification Summary certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology.

When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR SO.SSa(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR SO.SSa(b)(2)(xvi)(B) and full coverage credit may not be claimed.

Based on the configuration limited to single side access, relief is requested from the essentially 100 percent surface examination coverage requirements for the subject piping welds listed in Table 1 [reproduced as Table 3.9}. Note that examination coverage listed is that attained during examination with no credit taken for the far side of each weld in which examination from that side could not be performed.

Pursuant to 10 CFR SO.SSa(g)(S)(iii), relief is requested from the essentially 100 percent volumetric examination coverage requirement for the subject welds due to the geometric configuration and permanent obstructions which limit the volumetric examination coverage of the subject welds.

The limitations and the actual examination coverage attained for each weld for which relief is requested are noted in Table 1 [reproduced as Table 3.9].

- 42 Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld. This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment 3.9.5 Licensee's Proposed Alternative (as stated)

The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the POI for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.

Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present.

Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.9.6

NRC Staff Evaluation

ASME Code,Section XI, Examination Category C-F-1, Item Number C5.21, pressure retaining welds in piping requires volumetric examination of 100 percent of the weld volume as defined in Table IWC-2500-1 and shown in Figure IWC-2500-7. However, complete volumetric examinations are restricted by several factors, including pipe fitting, weld crown, and branch connection configurations. These conditions preclude the licensee obtaining full volumetric examinations from both sides of the weld. To gain access for examination, the welds would require design modifications. Imposition of this requirement would place a burden on the licensee; therefore, the ASME Code-required 100 percent volumetric examinations are impractical.

For the subject pipe welds, volumetric examinations were conducted using manual techniques qualified in accordance with performance demonstration requirements listed in ASME Code,Section XI, Appendix VIII.

Various scan limitations in the axial and circumferential directions were caused by the configuration of the welds and obstructions. As shown on the sketches and technical descriptions4 included in the licensee's submittal, examinations of the subject welds have been performed to the extent practical with the licensee obtaining volumetric coverage ranging from 46.5 to 78 percent (see Table 3.9 above) in the required areas.

The welds in ISIR-41 are not affected by stress corrosion cracking, and the most likely degradation mechanism is thermal fatigue. Thermal fatigue is a relatively slow process. Also, the coverage maps show that while the welds were not inspected to 100 percent of the code volume, the inspections for circumferential flaws does insonify most of the required volume.

4 The licensee's sketches and technical descriptions are not included in this SE.

- 43 The licensee completed the ASME Code-required surface examinations on the subject welds, with no limitations. No relevant indications were observed during any of the ultrasonic and surface examinations.

The licensee has shown that it is impractical to meet the ASME Code-required volumetric and surface examination coverage for the subject welds due to the design of the welds and proximity of other components. ConSidering the volumetric coverage obtained it is reasonable to conclude that if significant service-induced degradation had occurred in the subject welds, evidence of it would have been detected. Furthermore, the staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject welds.

3.10 RR ISIR-42 ASME Code,Section XI. Examination Category R-A, Items R1.11. R1.16 and R.120 3.10.1 ASME Code Components ASME Code Class:

Code Class 1 and 2 Risk Informed Inservice Inspection, Examination Category R-A, Risk Informed Piping Examinations.

Item Numbers R1.11, Elements Subject to Thermal Fatigue, R1.16, Elements Subject to Intergranular or Transgranular Stress Corrosion Cracking (IGSCC or TGSCC), and R1.20, Elements Not Subject to a Degradation Mechanism.

The component identifications and details are listed in Table 3.10.

3.10.2 ASME Code Requirement (as stated)

The examination requirements for Class 1 and 2 piping welds are governed by the Risk Informed Inservice Inspection program that was approved for use at CNP for their third inspection interval by the NRC in a Safety Evaluation Report dated September 28, 2007, (ADAMS Accession No. ML072620553). This program was developed in accordance with ASME Section XI Code Case N-716, Alternative Piping Classification and Examination Requirements.

Table 1 [reproduced as Table 3.10], Examination Category R-A, of Code Case N-716 requires 100 percent of the examination location to be examined. The alternative requirements of ASME Section XI, Code Case N-460, approved for use in Regulatory Guide 1.147, Revision 15, allow credit for essentially 100 percent coverage of the weld provided greater than 90 percent of the required volume has been examined. The regulations at 10 CFR 50.55a(b)(2)(xv)(A), requires the following examination coverage when applying Supplement 2 to Appendix VIII:

(1) Piping must be examined in two axial directions and when examination in the circumferential direction is required, the circumferential examination must be performed in two directions, provided access is available.

(2) Where examination from both sides is not possible, full coverage credit may be claimed from a single side for ferritic welds. Where examination from both sides is not

- 44 possible on austenitic welds, full coverage credit from a single side may be claimed only after completing a successful single side Appendix VIII demonstration using flaws on the opposite side of the weld.

The regulations in 10 CFR 50.55a{b)(2)(xvi){B), requires that examinations performed from one side of a stainless steel pipe weld must be conducted with equipment, procedures, and personnel that have demonstrated proficiency with single side examinations. To demonstrate equivalency to the two sided examinations, the demonstration must be performed to the requirements of Appendix VIII as modified by this paragraph and 10 CFR 50.55a(b)(2)(xv)(A).

Table 3.10 ASME UT Component Unit Weld Code Examination Material Remarks ID Description Item Coverage Number (Percent) 1-CS-96-60F (Class 1) 1 Elbow-to-Branch R1.11 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The exam limitation was due to the geometry of the branch limiting access from the downstream side.

No relevant indications detected.

1-SI-29-19S (Class 1) 1 Pipe-to-Tee R1.16 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side.

downstream, due to the sharp bevel adjacent to the tee side weld toe. No relevant indications I

detected.

- 45 Component ID Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 1-SI-29-20S 1

Elbow-to-Tee R1.16 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

1-SI-29-23S 1

Tee-to-Pipe R1.16 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

1-SI-31-21S 1

Elbow-to-Tee R1.16 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe. No relevant indications detected.

- 46 Component ID Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 2-S 1-57-19 2

Pipe-to-Tee R1.16 36.8 Stainless The completed (Class 1)

Steel examination was limited to 36.8%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%).

Additional coverage was missed due to the weld contour (13.2%). No relevant indications detected.

2-S 1-57-21 2

Elbow-to-Tee R1.16 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50.0%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam

= 50.0%). No relevant indications detected.

2-SI-56-18 2

Elbow-to-Tee R1.20 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50.0%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%).

No relevant indications detected.

- 47 ASME UT Component I Unit Weld Code Examination Material Remarks 10 Description Item Coverage Number (Percent) 1-SI-548-45S (Class 1) 1 Valve-to-Pipe R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. Full coverage was not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.

1-RH-30-0SF (Class 2) 1 Elbow-to-Valve R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. Full coverage was not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.

1-RC-8-02S 1

(Class 1)

Elbow-to-Pipe R1.20 89.7 Stainless Steel The completed examination was limited to 89.7%

coverage due to the configuration. Full coverage was not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.

1-SI-29-2SF (Class 1) 1 Elbow-to-Pipe R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. Full coverage was not obtainable due to the bevel at the weld toe on the valve side of the weld. No relevant indications detected.

- 48 ASME UT Component Unit Weld Code Examination Material Remarks 10 Description Item Coverage Number (Percent) 1-SI-33-26F (Class 1) 1 Nozzle-to-Elbow R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. Full coverage was not obtainable due to the Nozzle taper at the weld toe. No relevant indications detected.

2-RC-22-24 (Class 1) 2 Elbow-to-Valve R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.

2-RC-23-12 (Class 1) 2 Elbow-to-Valve R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.

2-RC-24..Q9 (Class 1) 2 Elbow-to-Valve R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the valve side due to the close proximity of the valve body to the weld. No relevant indications detected.

- 49 Component 10 2-SI-569-49S (Class 1)

Unit 2

2-SI-569-53S (Class 1) 2 2-SI-569-54S (Class 1) 2 Weld Description Tee-to-Pipe Elbow-to-Pipe Elbow-to-Pipe ASME Code Item Number R1.20 R1.20 R1.20 UT Examination Coverage (Percent) 50.0 50.0 50.0 Material Stainless Steel Stainless Steel Stainless Steel Remarks The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the Socket Welded fitting side. No relevant indications detected.

The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the Socket Welded fitting side. No relevant indications detected.

The completed examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the Socket Welded fitting side. No relevant indications detected.

- 50 Component 10 Unit Weld Description ASME Code Item Number UT Examination Coverage (Percent)

Material Remarks 2-SI-57-22 2

Tee-to-Pipe R1.20 48.4 Stainless The completed (Class 1)

Steel examination was limited to 48.4%

coverage due to the configuration. The configuration prevents examination on the tee side due to the sharp bevel adjacent to the tee side weld toe (single side exam = 50.0%).

Additional coverage was missed due to the weld contour (1.6%). No relevant indications detected.

2-SI-56-10 2

Pipe-to-Elbow R1.20 66.2 Stainless The completed (Class 1)

Steel examination was limited to 66.2%

coverage due to the configuration. The configuration prevents examination of 100% of the required area due to the presence of a permanent support which limited access.

No relevant indications detected.

2-SI-78-01 2

Pipe-to-Elbow R1.20 50.0 Stainless The completed (Class 1)

Steel examination was limited to 50%

coverage due to the configuration. The configuration prevents examination from the valve side due to its severe taper and close proximity of the valve to the weld. No relevant indications detected.

- 51 ASME UT Component Unit Weld Code Examination Material Remarks ID Description Item Coverage Number (Percent) 2-SI-56-22 (Class 1) 2 Elbow-to-Branch R1.20 50.0 Stainless Steel The completed examination was limited to 50%

coverage due to the configuration. The exam limitation was due to the geometry of the branch limiting access from the upstream side. No relevant indications detected.

3.10.3 Licensee's ASME Code Relief Request Pursuant to 10 CFR 50. 55a(g)(5)(iii), relief is requested from the 100 percent volumetric examination coverage requirement for austenitic piping welds with single side access.

3.10.4 Licensee's Basis for Relief Request (as stated)

There are currently no POI qualified single side examination procedures that demonstrate equivalency to two-sided examination procedures on austenitic piping welds. Current technology is not capable of reliably detecting or sizing flaws on the far side of an austenitic weld for configurations common to United States nuclear applications.

POI Performance Demonstration Qualification Summary certificates for austenitic piping list the limitation that single side examination is performed on a best effort basis. The best effort qualification is provided in place of a complete single side qualification to demonstrate that the examiners qualification and the subsequent weld examination is based on application of the best available technology.

When the examination area is limited to one side of an austenitic weld, examination coverage does not comply with 10 CFR 50.55a(b)(2)(xv)(A) and proficiency demonstrations do not comply with 10 CFR 50.55a(b)(2)(xvi)(B) and full coverage credit may not be claimed.

Based on the configuration limited to single side access, relief is requested on complying with the 100 percent required examination coverage for the piping welds listed in Table 1 [reproduced as Table 3.10]. Note that examination coverage listed is that which was obtained during examination with no credit taken for the far side of each weld when only single-sided access was attainable.

Other welds in Table 1 [reproduced as Table 3.10] have physical limitations that prevented full access from both sides of the weld. These limitations include pipe support members, transition areas on elbows, tapers and other geometric interferences. Compliance with code requirements would require extensive modification or replacement of components with a design that allows examination from both sides of the weld.

- 52 Compliance with code requirements requires extensive modification or replacement of components with a design that allows examination from both sides of the weld.

This option to meet the required 100 percent volume examination coverage is considered impractical based on the cost, additional radiation exposure and impact to plant equipment.

3.10.5 Licensee's Proposed Alternative (as stated)

The subject welds received a volumetric examination to the maximum extent practical utilizing the best available techniques, as qualified through the PDI for Supplement 2 with demonstrated best effort for single sided examination, from the accessible side of the weld. Additionally, a surface examination without limitations was performed on each weld. Further, a visual (VT-2) examination is performed each inspection period during the system leakage tests as required by Section XI, Table IWC-2500-1, Category C-H.

Based upon the examination volumes that were obtained with acceptable results along with the completed surface examination and the visual (VT-2) examination performed each inspection period, it is reasonable to conclude that service induced degradation would be detected if present.

Therefore, these proposed alternatives provide an acceptable level of quality and safety by providing reasonable assurance of structural integrity of the subject welds.

3.10.6 NRC Staff Evaluation Risk Informed Inservice Inspection, Examination Category R-A, Risk Informed Piping Examination Item Numbers R1.11, R1.16, and R1.20 require volumetric examination of 100 percent of the weld volume as defined in Table 1 of ASME Section XI Code Case N716 and shown in Figures IWB-2500-8, -9, -10, or -11. Complete volumetric examinations were restricted by several factors for the welds described in Table 3.10, including pipe fitting, weld crown, and branch connection configurations. These conditions preclude the licensee obtaining full volumetric examinations from both sides of the weld. To gain access for examination, the welds would require design modifications. Imposition of this requirement would place a burden on the licensee; therefore, the ASME Code-required 100 percent volumetric examinations are impractical.

For the subject pipe welds, volumetric examinations were conducted using manual techniques qualified in accordance with performance demonstration requirements listed in ASME Code,Section XI, Appendix VIII. The longitudinal wave method is believed capable of detecting planar inside diameter (ID) surface-breaking flaws on the far-side of wrought stainless steel welds.

Studies (see References 2 and 3) reported in the technical literature recommend the use of both shear and longitudinal waves to obtain the best detection results, with minimum false calls, in austenitic welds.

Various scan limitations in the axial and circumferential directions were caused by the configuration of the welds and obstructions. As shown on the sketches and technical descriptions5 included in the licensee's submittal, examinations of the subject welds have been performed to the extent practical with the licensee obtaining volumetric coverage ranging from The licensee's sketches and technical descriptions are not included in this SE.

5

- 53 36.8 to 89.7 percent (see Table 3.10 above) in the required areas. The welds were examined using probes that provide several combinations of ultrasonic angles and frequencies. All examinations of the welds in Table 3.10 used 45 degree shear wave probes. Most also used 60 degree shear waves and/or 60 degree longitudinal wave probes.

The welds in ISIR-42 are not affected by stress corrosion cracking, and the most likely degradation mechanism is thermal fatigue. Thermal fatigue is a relatively slow process. Also, the coverage maps show that while the welds were not inspected to 100 percent of the code volume, the inspections for circumferential flaws does insonify most of the required volume.

The licensee completed the ASME Code-required surface examinations on the subject welds, with no limitations. No relevant indications were observed during any of the ultrasonic and surface examinations.

The licensee has shown that it is impractical to meet the ASME Code-required volumetric and surface examination coverage for the subject welds due to the design and materials of the welds and welded components. Considering the volumetric coverage obtained it is reasonable to conclude that if significant service-induced degradation had occurred in the subject welds, evidence of it would have been detected. Furthermore, the NRC staff determined that the examinations performed provide reasonable assurance of structural integrity of the subject welds.

4.0 CONCLUSION

S As set forth above, the NRC staff has reviewed the licensee's submittals and determined that the ASME Code examination coverage requirements are impractical for the subject welds listed in relief requests ISIR-33, ISIR-34, ISIR-35, ISIR-36, ISIR-37, ISIR-38, ISIR-39, ISIR-40, ISIR-41, and lSI R-42. The NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(g)(6)(i), and is in compliance with the requirements of 10 CFR 50.55a with the granting of these reliefs.

The NRC staff concludes that based on the volumetric, surface and/or visual examination coverage obtained that the examinations performed to the extent practical provide reasonable assurance of structural integrity of the subject components.

Therefore, the NRC staff grants relief for the subject examinations of the components contained in relief requests ISIR-33, ISIR-34, ISIR-35, ISIR-36, ISIR-37, ISIR-38, ISIR-39, ISIR-40, ISIR-41, and ISIR-42, for CNP Units 1 and 2, for the third inservice inspection interval which ended on April 9, 2010.

The staff has further determined that granting relief pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest given due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.

All other ASME Code,Section XI requirements for which relief was not specifically requested and approved in the subject requests for relief remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.

- 54

5.0 REFERENCES

1.

P. G. Heasler, and S. R. Doctor, 1996, Piping Inspection Round Robin, NUREG/CR-5068, PNNL-10475, U. S. Nuclear Regulatory Commission, Washington, DC.

2.

Ammirato FV, X Edelmann and SM Walker, 1987, "Examination of Dissimilar Metal Welds in BWR Nozzle-to-Safe End Joints," 8th International Conference on NDE in the Nuclear Industry, ASM International.

3.

P. Lemaitre, TD Koble, and SR Doctor, 1995, "PISC III Capability Study on Wrought-to-Wrought Austenitic Steel Welds: Evaluation at the Level of Procedures and Techniques," Effectiveness of Nondestructive Examination Systems and Performance Demonstration, PVP-Volume 317, NDE-Volume 14, ASME.

Principal Contributors: Thomas McLellan, NRRlDE Stephan Cumblidge, NRR/DE Date: April 26, 2012

L. J. Weber

- 2 If you have any questions, please contact the Project Manager, Mr. Peter Tam, at (301) 415-1451.

Sincerely, IRAI Istvan Frankl, Acting Chief Plant Licensing Branch 111-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316

Enclosure:

Safety Evaluation cc w/encl: Distribution via ListServ Distribution:

PUBLIC RidsOgcRp Resource RidsNrrDorILpI3-'1 Resource LPL3-1 R/F RidsNrrDeEpnb Resource S. Williams, EDO Rill RidsNrrLABTully Resource RidsNrrDeEvib Resource T. McLellan, NRR RidsNrrPMDCCook Resource RidsAcrsAcnw_MailCTR Resource S. Cumblidge, NRR RidsRgn3MailCenter Resource ADAMS ACCESSION NO.. ML12109A100

• SE t ransml"tted b lY memo d t a e d 04/10/2012 OFFICE LPL3-1/PM LPL3-1/LA EVIB/BC EPNB/BC LPL3-1/BC NAME TBeitz BTuily SRosenberg

• TLupold (DAiley for)

• IFrankl DATE 04/18/12 04/20/12 04/10/12 04/10/12 04/26/12 OFFICIAL RECORD COPY