GNRO-2012/00040, Relief Request ISI-17 Repair Plan for Lsi Weld N06B-KB

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Relief Request ISI-17 Repair Plan for Lsi Weld N06B-KB
ML12124A245
Person / Time
Site: Grand Gulf Entergy icon.png
Issue date: 05/02/2012
From: Perino C
Entergy Operations
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
GNRO-2012/00040, TAC MD2663
Download: ML12124A245 (29)
v • d • e


Text

,.Entergy

.--==- Entergy Operations, Inc.

P.o. Box 756 Port Gibson, Mississippi 39150 Tel: 601-437-2800

~._--_.. _ __

Christina Perino Licensing Manager GNRO-2012/00040 May 2,2012 U.S, Nuclear Regulatory Commission (NRC)

Attn: Document Control Desk Washington, D,C. 20555

Subject:

Grand Gulf Nuclear Station (GGNS) Relief Request ISI-17 Repair Plan for lSI Weld N06B-KB Grand Gulf Nuclear Station (GGNS), Unit 1 Docket No, 50-416 License No. NPF-29

References:

1. NRC Letter, Pilgrim Nuclear Power Station' Relief Request No. PRR-15, Rev. 01, Approval to Include Remaining Reactor Pressure Vessel (RPV) Safe-End Welds in Contingency Repair Plan for Full Structural Weld Overlays (TAC No. MD2663), dated April 2, 2007 2, NRC Letter, Pilgrim Nuclear Power Station' Pilgrim Relief Request PRR-39, Alternative Contingency Repair Plan for Reactor Pressure Vessel Nozzle Safe-End and Dissimilar Metal Piping Welds Using ASME Code Cases N-638 and N-504-2, With Exceptions (TAC No. MC2496), dated April 12, 2005
3. NRC Letter, Arkansas Nuclear One, Unit No,1 -Approval of Relief Request AN01 -R&R-011 to Use a Proposed Alternative to the American Society of Mechanical Engineers Boiler and Pressure Vessel Code Requirements for Weld Overlay Repairs (TAC No.

MD6958), dated June 18, 2008 4, NRC Letter, James A. FitzPatrick Nuclear Power Plant- Request for Alternative JAF RR-7, Rev. 1 to Install a Weld Overlay on N2C Nozzle to Recirculation Inlet Piping Safe-End Dissimilar Metal Weld (TAC No, MD9780), dated April 1,2009

5. NRC Letter, Pilgrim Nuclear Power Station - Pilgrim Relief Request (PRR)-19, to Install a Weld Overlay on Jet Pump Instrumentation Nozzle Weld RPV-N9A-1 (TAC NO. ME1151), Dated September 11,2009

GNRO-2012/00040 Page 2 of 3

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy requests NRC approval of Grand Gulf Nuclear Station (GGNS) Relief Request ISI-17, to perform an alternative repair of Residual Heat Removal (RHR) I Low Pressure Core Injection (LPCI) "C n Nozzle to Safe End Weld N06B-KB using the provisions of American Society of Mechanical Engineers (ASME) Code Cases N-638-4 and N-504-4. The NRC has previously approved similar alternatives for repairs of Safe End Welds at Pilgrim, ANO-1, and James A. Fitzpatrick (JAF) Nuclear Power Plants (References 1 - 5). The proposed alternative follows the NRC approved precedents and the past weld overlays have maintained the reactor pressure boundaries. Therefore the proposed alternative provides an acceptable level of quality and safety.

GGNS is presently in Refueling Outage RF-18. During this outage, lSI weld N06B-KB, RHR/LPCI "c" Nozzle to Safe End Weld, was ultrasonically (UT) examined to comply with the inspection requirements of BWRVIP-75A for Category "c" welds. The UT examinations were performed in accordance with Appendix VIII, Supplement 10 as implemented by the Performance Demonstration Initiative (PDI). In performing this UT examination, an indication indicative of intergranular stress corrosion cracking (IGSCC) was detected. The N06B-KB nozzle to safe end weld was last examined in 2002. This examination was performed in accordance with ASME Section XI, 1977 Edition through and including the 1979 Summer Addenda and no flaws were observed at that time. This was pre-Appendix VIII requirements.

Entergy intends to use Code Cases N-504-4 and N-638-4 to install a structural weld overlay (WOL) on the GGNS RHRI LPCI "c" Nozzle to Safe End Weld, N06B-KB. To do this, Entergy has initiated Relief Request ISI-17 (Enclosure 1) to propose several alternatives to specific ASME Section XI Code requirements in Code Cases N-504-4 and N-638-4, as conditionally approved by the NRC in Regulatory Guide 1.147. The full structural WOL will be applied by deposition of ERNiCrFe-7A (Alloy 52M) filler metal on the outside surface of the dissimilar metal weld (DMW) and adjacent base materials.

Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy requests NRC approval of the proposed alternative by May 15, 2012, to complete the N06B-KB weld repair within the Refueling Outage 18 Schedule.

The commitments made in this submittal are identified in Enclosure 2.

If you have questions or require additional information concerning this report, please contact Mr. Stephen Scott at (601) 368-5456.

Sincerely, CLP\rrj

Enclosures:

1. Relief Request ISI-17
2. List of Regulatory Commitments Attachments: (See Next Page)

GNRO-2012/00040 Page 3 of 3 Attachments: 1. RHR/LPCI "C" Nozzle to Safe End Weld N06B-KB Details and Figures

2. Comparison of ASME Section XI Appendix VIII, Supplement 11 to POI cc:

NRC Senior Resident Inspector Grand Gulf Nuclear Station Port Gibson, MS 39150 u.S. Nuclear Regulatory Commission ATTN: Mr. Elmo E. Collins, Jr.

Region Administrator, Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511

u. S. Nuclear Regulatory Commission ATTN: Mr. Alan Wang, NRRIDORL Mail Stop OWFN/8 B1 Washington, DC 20555-0001

Enclosure 1 To GNRO-2012100040 Relief Request 151-17 of GNRO-2012/00040 Relief Request ISI-17 ENTERGY NUCLEAR OPERATIONS, INC.

Grand Gulf Nuclear (GGNS)

REQUEST FOR RELIEF I. ASME CODE COMPONENTS AFFECTED Components: lSI Weld N06B-KB Residual Heat Removal (RHR)/Low Pressure Core Injection (LPCI) "c" Nozzle to Safe End Weld Code Class: 1

References:

1. ASME Section XI, 2001 Edition/2003 Addenda except as listed in References 2 and 3
2. ASME Section XI, 2001 Edition to be used for Appendix VIII, "Performance Demonstration for Ultrasonic Examination Systems"
3. Appendix Q of ASME Section XI, 2004 Edition/2005 Addenda as required by Regulatory Guide 1.147
4. ASME Code Case N-716, Alternative Piping Classification and Examination Requirements
5. ASME Code Case N-504-4, Alternate Rules for Repair of Classes 1, 2, and 3 Austenitic Stainless Steel Piping
6. ASME Code Case N-638-4, Similar and Dissimilar Metal Welding using Ambient Temperature Machine GTAW Temper Bead Technique
7. ASME Section III, 1971 EditionlWinter 1972 Addenda
8. ASME Section III, 1992 Edition/No Addenda
9. SEP-ISI-102, ASME Section XI, Division 1 Inservice Inspection Interval (lSI) Program
10. EPRI Report GC-111050, Ambient Temperature Preheat for Machine G TA W Temperbead Applications
11. EPRI Report BWRVIP-75-A, Technical Basis for Revisions to Generic Letter 88-01 Inspection Schedules (1012621)

Unit /Inspection Grand Gulf Nuclear Station / Third (3 rd ) 10-Year Interval Interval Applicability:

Page 1 of 10 of GNRO-2012/00040 Relief Request 151-17 II. APPLICABLE CODE REQUIREMENT American Society of Mechanical Engineers (ASME)Section XI, IWA-4411 requires that repair/replacement activities be performed in accordance with the Owner's Requirements and the original Construction Code of the component or item. Alternatively, IWA-4411 (a) and (b) allow use of later Editions/Addenda of the Construction Code - either in its entirety or portions thereof, Code Cases, and revised Owner Requirements. IWA-4420 specifies requirements for performing defect removal and the associated nondestructive examinations for repairs performed with and without welding. IWA-4600(b) provides temper bead welding requirements as an alternative to the welding and postweld heat treatment requirements of the Construction Code. Preservice/inservice (lSI) examination requirements for lSI weld N06B-KB are as specified in Table 1 (Examination Category R-A) of Code Case N-716.

As an alternative to the above, ASME Section XI Code Cases N-504-4 and N-638-4 specify requirements for performing the following:

  • Code Case N-504-4 provides alternative requirements to reduce a defect to a flaw of acceptable size in austenitic stainless steel materials by deposition of a structural weld overlay (WOL) on the outside surface of the pipe or component. The NRC has conditionally approved this Case in Regulatory Guide 1.147 with the following condition:

"The provisions of Section XI, Nonmandatory Appendix Q, "Weld Overlay Repair of Class 1, 2, and 3 Austenitic Stainless Steel Piping Weldments," must also be met. In addition, the following conditions shall be met: (a) the total laminar flaw area shall not exceed 10% of the weld surface area, and no linear dimension of the laminar flaw area shall exceed the greater of 3 inches or 10% of the pipe circumference; (b) the finished overlay surface shall be 250 micro-in (6.3 micrometers) root mean square or smoother; (c) the surface flatness shall be adequate for ultrasonic examination; and (d) radiography shall not be used to detect planar flaws under or masked by laminar flaws."

  • Code Case N-638-4 establishes requirements for performing ambient temperature temper bead welding as an alternative to the preheat and postweld heat treatment (PWHT) requirements of the Construction Code. The NRC has conditionally approved this Case in Regulatory Guide 1.147 with the following conditions:

"(1) Demonstration for ultrasonic examination of the repaired volume is required using representative samples which contain construction type flaws.

"(2) The provisions of 3(e)(2) or 3(e)(3) may only be used when it is impractical to use the interpass temperature measurement methods described in 3(e)(1), such as in situations where the weldment area is inaccessible (e.g., internal bore welding) or when there are extenuating radiological conditions."

III. REASON FOR PROPOSED ALTERNATIVE Intergranular stress corrosion cracking (IGSCC) in boiling water reactor (BWR) piping was identified as a problem in the United States in the early 1970s. Initially, cracking was only observed in small-bore piping. However, in 1982 cracking caused by IGSCC was also identified in large-bore piping. GGNS manages this condition by performing routine inservice inspections in accordance with ASME Section XI and the inspection requirements of BWRVIP-75A.

Page 2 of 10 of GNRO-2012/00040 Relief Request 151-17 GGNS is presently in Refueling Outage RF-18. During this outage, lSI weld N06B-KB, RHRlLPCI "C" Nozzle to Safe End Weld, was ultrasonically (UT) examined to comply with the inspection requirements of BWRVIP-75A for Category "C,,1 welds. The UT examinations were performed in accordance with Appendix VIII, Supplement 10 as implemented by the Performance Demonstration Initiative (PDI). In performing this UT examination, an indication indicative of intergranular stress corrosion cracking (IGSCC) was detected. The indication is axially oriented and wholly located within the weld and butter. The length of the indication is 0.90". The depth of the indication is 0.472" with a remaining ligament from the outside surface of 0.90". The indication is located 8.1" from top-dead-center looking into the vessel (clockwise).

See Table 1 and Figure 1 of Attachment 1 for additional details.

Entergy intends to repair lSI weld N06B-KB by installing a structural weld overlay (WOL).

Structural WOLs have been used for years on piping of both boiling water reactors (BWRs) and pressurized water reactors (PWRs) to arrest the growth of flaws while establishing a new structural pressure boundary. However, the 2001 Edition/2003 Addenda of ASME Section XI, which is the GGNS code of record for performing repair/replacement activities, does not include requirements for installing structural WOLs on dissimilar metal welds (DMWs) and non-austenitic stainless steels. Moreover, requirements for installing full structural WOLs on DMWs and non-austenitic stainless steels are not presently included in any Edition/Addenda of ASME Section XI or Code Cases approved by the NRC.

WOLs on DMWs and non-austenitic stainless steels in BWRs have generally been applied in accordance with various revisions of ASME Code Cases N-504 and N-638. At present, code case revisions N-504-4 and N-638-4 are "conditionally accepted" by the NRC in Regulatory Guide 1.147. Application of these code cases to DMWs and non-austenitic stainless steels requires a relief request since Code Case N-504-4 was written specifically for austenitic stainless steel weldments and Code Case N-638-4 contains some restrictions and requirements that do not apply to the proposed GGNS WOL.

Entergy intends to use Code Cases N-504-4 and N-638-4 to install a structural WOL on lSI Weld N06B-KB. To do this, Entergy has initiated this Request to propose alternatives to certain requirements in these code cases. The full structural WOL will be applied by deposition of ERNiCrFe-7A (Alloy 52M) filler metal on the outside surface of the DMW and adjacent base materials. See Figure 2 of Attachment 1 for additional details.

IV. PROPOSED ALTERNATIVE Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy proposes an alternative to specific ASME Section XI Code requirements in Code Cases N-504-4 and N-638-4, as conditionally approved by the NRC in RegUlatory Guide 1.147. The proposed alternatives for each ASME Section XI code case are specified below:

1 As defined in BWRVIP-75A, Category "c" welds "are those not made with resistant materials and that have been treated by an 81 process after more than two years of operation. As part of the process, a UT examination is required after the 81 treatment to ensure the weldment is not cracked."

Page 3 of 10 of GNRO-2012100040 Relief Request 151-17 A. Code Case N-504-4 (as conditionally approved in Regulatory Guide 1.147)

1. Code Case N-504-4 and Appendix Q apply strictly to austenitic stainless steel piping and weldments. As an alternative, Entergy proposes to use Code Cases N-504-4 and Appendix Q to install a WOL on SA-508, Class 2 low alloy steel, Alloy 182/82 weld, and an SB-166, Alloy 600 nickel alloy safe-end using ERNiCrFe-7A (Alloy 52M) filler metal.
2. Code Case N-504-4, paragraph (b) and Appendix Q, paragraph Q-2000(a) require that weld metal used to fabricate WOLs be low carbon steel (0.035%) austenitic stainless steel. As an alternative, Entergy proposes to perform WOL welding using ERNiCrFe-7A (Alloy 52M). Therefore, this requirement does not apply.
3. Code Case N-504-4, paragraph (e) and Appendix Q, paragraph Q-2000(d) require that the WOL consist of at least two austenitic stainless steel weld layers, each layer having an as-deposited delta ferrite content of at least 7.5 FN or 5 FN under certain conditions. As an alternative, Entergy proposes to perform WOL welding using ERNiCrFe-7A (Alloy 52M) which is purely austenitic. Therefore, this delta ferrite requirement does not apply.
4. Code Case N-504-4, paragraph (h) requires that a system hydrostatic test be performed in accordance with IWA-5000. As an alternative, Entergy proposes to perform a system leakage test in accordance with IWA-5000.
5. Appendix Q, paragraph Q-4000 specifies that procedures and personnel for examining weld overlays be qualified in accordance with Appendix VIII (Supplement 11) of ASME Section XI. As an alternative, Entergy proposes to UT examine the WOL in accordance with Appendix VIII, Supplement 11 except as modified by the POI Program. The proposed POI alternatives to Appendix VIII, Supplement 11 are specified in Attachment 2 B. Code Case N-638-4 (as conditionally approved in Regulatory Guide 1.147)
1. Code Case N-638-4, paragraphs 3(e) and 3(e)(1) state that the interpass temperature during welding shall be determined by temperature measurement (e.g., pyrometers, temperature indicating crayons, thermocouples). In monitoring preheat and interpass temperatures during WOL welding, Entergy proposes the following alternative:

"Preheat and interpass temperatures will be measured using a contact pyrometer.

In the first three layers, the interpass temperature will be measured every three to five passes. After the first three layers, interpass temperature measurements will be taken every six to ten passes for the subsequent layers. Contact pyrometers will be calibrated in accordance with approved calibration and control program documents."

2. Code Case N-638-4, paragraphs 4.0(a), 4.0(a)(2), and 4.0(a)(4) state that all welds (including repair welds) shall be volumetrically examined in accordance with the requirements and acceptance criteria of the Construction Code or ASME Section III.

As an alternative, Entergy proposes to volumetrically examine the WOL using the UT method in accordance with the requirements and acceptance criteria of paragraph Q-4100 of ASME Section XI, Appendix Q.

Page 4 of 10 of GNRO-2012100040 Relief Request ISI-17 V. BASIS FOR PROPOSED ALTERNATIVE Entergy intends to install a WOL on lSI weld N06B-KB in accordance with ASME Section XI Code Case N-504-4 as supplemented by Nonmandatory Appendix Q and Code Case N-638-4 using the proposed alternatives specified in Section IV of this Request. These code cases have been conditionally approved by the NRC in Regulatory Guide 1.147.

This proposed alternative provides an acceptable methodology for preventing potential failures due to IGSCC based on the use of filler metals that are resistant to IGSCC (e.g., Alloy 52M),

procedures that create compressive residual stress profiles along the inside diameter of the original weld, and post-overlay preservice and inservice inspection requirements that ensure structural integrity for the life of the plant.

1. WOL Design and Verification The fundamental design basis for full structural WOLs is to maintain the original design margins with no credit taken for the underlying IGSCC-susceptible weldments. The assumed design basis flaw for the purpose of structural sizing of the WOL is a flaw completely around the circumference (360°) and 100% through the original wall thickness of the dissimilar metal weld. Regarding the crack growth analysis, the detected axial flaw described in Section III, above, will be analyzed. The specific analyses and verifications to be performed are summarized as follows:
  • A nozzle-specific stress analysis will be performed to establish a residual stress profile in the WOL and the underlying weld and base materials. A severe internal diameter weld repair will be assumed in this analysis that effectively bounds any actual weld repairs that may have occurred. The analysis will then simulate application of the WOL to determine the final residual stress profile. Post-WOL residual stresses at normal operating conditions will be shown to result in beneficial compressive stresses on the inside surface of the underlying weld and base materials, assuring that further crack initiation in susceptible materials due to IGSCC is highly unlikely.
  • Fracture mechanics analyses will also be performed to predict crack growth of the detected flaw. Crack growth due to IGSCC and fatigue will be analyzed. The crack growth analyses will consider all design loads and transients, plus the post-WOL and through-wall residual stress distributions. The analyses will demonstrate that postulated flaws will not degrade the design basis for the WOL.
  • The analyses will demonstrate that applying the WOL does not impact the conclusions of the existing nozzle stress reports. The ASME Code,Section III primary stress criteria will continue to be met.
  • Shrinkage will be measured during the WOL application. Shrinkage stresses at other locations in the piping systems arising from the WOL will be demonstrated not to have an adverse effect on the systems. Clearances of affected supports and restraints will be checked after the overlay repair and will be reset within the design ranges if required.
  • The added weight on the piping systems due to the WOL will be evaluated for potential impact on piping system stresses and dynamic characteristics.

Page 5 of 10 of GNRO-2012100040 Relief Request 151-17

  • The as-built dimensions of the WOL will be measured and evaluated to demonstrate that they meet or exceed the minimum design dimensions of the WOL.
2. Suitability of Proposed Alternatives to Code Case N-504-4 and Appendix Q WOLs have been used for repair and mitigation of cracking in BWRs since the early 1980s.

In Generic Letter (GL) 88-01, NRC Position on Intergranular Stress Corrosion Cracking (IGSCC) in BWR Austenitic Stainless Steel Piping, the NRC approved the use of ASME Section XI acceptance standards for determining the acceptability of installed WOLs.

Accordingly, a WOL will be installed on lSI weld N06B-KB in accordance with ASME Section XI Code Case N-504-4 and Appendix Q. Compliance with Appendix Q is required by Regulatory Guide 1.147. However, as described in Section IV of this Request, Entergy has proposed several alternatives to Code Case N-504-4 and Appendix Q that are necessary to support the installation of the new WOL. The suitability of the proposed alternatives is provided below.

(a) Code Case N-504-4 and Appendix Q apply strictly to austenitic stainless steel piping and weldments. As an alternative, Entergy has proposed to use Code Cases N-504-4 and Appendix Q to install a WOL on SA-508, Class 2 low alloy steel, Alloy 182/82 weld, and an SB-166, Alloy 600 nickel alloy safe-end using ERNiCrFe-7A (Alloy 52M) filler metal. This proposed alternative is acceptable because the WOL design, fabrication, examination, and preservice/inservice inspection requirements of Code Case N-504-4 and Appendix Q may also be applied to nickel alloy WOLs of non-austenitic stainless steels. While some material requirements in Code Case N-504-4 and Appendix Q may only apply to austenitic stainless steels, Entergy has identified these requirements and proposed alternatives to appropriately address them.

(b) Code Case N-504-4, paragraph (b) and Appendix Q, paragraph Q-2000(a) require that weld metal used to fabricate WOLs be low carbon steel (0.035%) austenitic stainless steel. This requirement was included in Code Case N-504-4 and Appendix Q to reduce the sensitization potential of the austenitic stainless steel WOL, thereby reducing its susceptibility to IGSCC. As an alternative, Entergy has proposed to perform WOL welding using ERNiCrFe-7A (Alloy 52M) weld metal. While carbon content is not a critical factor in assessing resistance of nickel alloys to IGSCC, the chromium content is. As documented in Section 3.1 of the ASME white paper (RRM-02-05/BC04-1003) which supported Code Case N-740, a minimum chromium content of 20% is necessary to ensure resistance to IGSCC. Because ERNiCrFe-7A (Alloy 52M) weld metal has a high chromium content (28 - 31.5%), it has excellent resistance to IGSCC.

(c) Code Case N-504-4, paragraph (e) and Appendix Q, paragraph Q-2000(d) require that the WOL consist of at least two austenitic stainless steel weld layers, each layer having an as-deposited delta ferrite content of at least 7.5 FN or 5 FN under certain conditions. This requirement was included in Code Case N-504-4 and Appendix Q to reduce the sensitization potential of the austenitic stainless steel WOL, thereby reducing its susceptibility to IGSCC. As an alternative, Entergy has proposed to perform WOL welding using ERNiCrFe-7A (Alloy 52M) weld metal which has a purely austenitic microstructure. Therefore, the requirement to measure delta ferrite does not apply in this application. The susceptibility of nickel alloys to IGSCC is dependant on its chromium content as explained above. Furthermore, the chromium content of the first layer of Alloy 52M weld metal could be reduced due to dilution with the underlying Page 6 of 10 of GNRO-2012100040 Relief Request 151-17 base and weld materials. Because this is the case, Entergy has imposed the following restriction on the first layer of the WOL which is consistent with ASME Section XI Code Case N-740-2:

"The first layer of Alloy 52M weld metal deposited may not be credited toward the required thickness. Alternatively, a diluted layer may be credited toward the required thickness, provided the portion of the layer over the austenitic base material, austenitic weld, and the associated dilution zone from an adjacent ferritic base material contains at least 20% chromium. The chromium content of the deposited weld metal may be determined by chemical analysis of the production weld or from a representative coupon taken from a mockup prepared in accordance with the WPS (or a representative WPS) for the production weld."

(d) Code Case N-504-4, paragraph (h) requires that a system hydrostatic test be performed in accordance with IWA-5000 when a flaw penetrates the pressure boundary. If the pressure boundary has not been penetrated, Code Case N-504-4 allows performance of a system leakage test. Pressure testing is not addressed by Appendix Q. As an alternative, Entergy proposes to perform a system leakage test in accordance with IWA-5000. This proposal is consistent with the pressure testing requirements of IWA-4540 and Code Case N-416-4, except that, the NDE requirements of IWA-4540/N-416-4 would not apply to a WOL. The WOL acceptance examination will include both liquid penetrant (PT) and UT examinations. PT examinations will be performed in accordance with ASME Section III while the UT examination will be performed in accordance with Appendix VIII, Supplement 11 of ASME Section XI as implemented by PDI. The UT acceptance standards are specified in Appendix Q, Q-4100(c) which defaults to Tables IWB-3514-2 and 3. This proposal is consistent with Code Case N-740-2 which requires performance of a system leakage test in accordance with IWA-5000.

(e) Appendix Q, paragraph Q-4000 specifies that procedures and personnel for examining weld overlays be qualified in accordance with Appendix VIII of ASME Section XI.

Appendix VIII, Supplement 11 of the 2001 Edition of ASME Section XI specifies requirements for performance demonstration of ultrasonic examination procedures, equipment, and personnel used to detect and size flaws in full structural overlays of wrought austenitic piping welds. Entergy modifies the Appendix VIII, Supplement 11 qualification requirements by the proposed alternatives in the Performance Demonstration Initiative (PDI) Program as indicated in Attachment 2 of this request because the industry cannot meet the requirements of Appendix VIII, Supplement 11.

Therefore, the PDI modifications to ASME Section XI Appendix VIII, Supplement 11 as described in Attachment 2 will be used for qualification of ultrasonic examinations used to detect and size flaws in the preemptive full structural weld overlays of this request.

3. Suitability of Proposed Alternatives to Code Case N-638-4 An ambient temperature temperbead welding technique will be used when welding on the ferritic base material of the Reactor Pressure Vessel (RPV) nozzle (for lSI weld N06B-KB) in lieu of the PWHT requirements of ASME Section III. Research by the Electric Power Research Institute (EPRI) and other organizations on the use of an ambient temperature temperbead process using the machine gas tungsten arc welding (GTAW) process is documented in EPRI Report GC-111 050. According to the EPRI report, repair welds performed with an ambient temperature temperbead procedure utilizing the machine GTAW Page 7 of 10 of GNRO-2012100040 Relief Request 151-17 process exhibit mechanical properties equivalent to or better than those of the surrounding base material. Laboratory testing, analysis, successful procedure qualifications, and successful repairs have all demonstrated the effectiveness of this process.

The ambient temperature temperbead technique of Code Case N-638-4 will be used. Code Case N-638-4 was conditionally approved by the NRC in Regulatory Guide 1.147. The suitability of the proposed alternatives is provided below.

(a) Code Case N-638-4, paragraphs 3(e) and 3(e)(1) state that the interpass temperature during welding shall be determined by temperature measurement (e.g., pyrometers, temperature indicating crayons, thermocouples). In monitoring preheat and interpass temperatures during WOL welding, Entergy proposes the following:

"The preheat and interpass temperatures will be measured using a contact pyrometer. In the first three layers, the interpass temperature will be measured every three to five passes. After the first three layers, interpass temperature measurements will be taken every six to ten passes for the subsequent layers.

Contact pyrometers will be calibrated in accordance with approved calibration and control program documents."

The proposed preheat and interpass temperature controls are based on field experience with depositing WOLs and have been successfully used throughout the industry. Interpass temperatures beyond the third layer have no impact on the metallurgical properties of the low alloy steel heat affected zone.

(b) Code Case N-638-4, paragraphs 4.0(a), 4.0(a)(2), and 4.0(a)(4) state that all welds (including repair welds) shall be volumetrically examined in accordance with the requirements and acceptance criteria of the Construction Code or ASME Section III.

As an alternative, Entergy proposes to volumetrically examine the WOL using the UT method in accordance with the requirements and acceptance criteria of Appendix Q, Section Q-4100 of ASME Section XI. The UT examination requirements and acceptance standards in Appendix Q, paragraph Q-4100 were developed specifically for WOLs unlike those in Code Case N-638-4. According to Article Q-4000, UT examination procedures and personnel shall be qualified in accordance with Appendix VIII of ASME Section XI. Supplement 11 of Appendix VIII specially addresses qualification requirements for WOLs. When UT examinations are performed in accordance with Appendix VIII, Supplement 11 (as implemented through POI), the examinations are considered more sensitive for detecting fabrication and service-induced flaws than traditional radiographic and ultrasonic examination methods.

Furthermore, construction-type flaws have been included in the POI qualification sample sets for evaluating procedures and personnel. Appendix Q, Article Q-41 00 also establishes UT acceptance standards for WOL examinations. Similar to NB-5330, the UT examination must assure adequate fusion with the base material and detect welding flaws such as interbead lack of fusion, inclusions, and cracks.

Detected planar and laminar flaws are required to meet the acceptance standards of Tables IWB-3514-2 and 3, respectively. Paragraph Q-4100(c) also limits the reduction in coverage due to a laminar flaw to less than 10% while uninspectable volumes are assumed to contain the largest radial planar flaw that could exist within the volume.

The conditions in Regulatory Guide 1.147 applicable to Appendix Q will also be met.

Page 8 of 10 of GNRO-2012100040 Relief Request ISI-17

4. Additional NDE Information The length, surface finish, and flatness of the WOL will comply with 0-4100(a) to facilitate examination in accordance with ASME Section XI, Appendix Q. Figure Q-41 00-1 describes the examination volume for acceptance examinations while Figure Q-4300-1 does the same for preservice and inservice examinations. Preservice and inservice examination requirements are specified in 0-4200 and Q-4300 of Appendix Q. The examinations required by Code Case N-504-4/Appendix Q and Code Case N-638-4 as amended by the proposed alternatives of this Request will provide adequate assurance that the integrity of the proposed WOL is consistent with the structural integrity assumptions of the design.
5. NRC Submittals As listed in Enclosure 2, Entergy will submit the following information to the NRC within fourteen (14) days from completing the final ultrasonic examinations of the completed WOL:

2

  • WOL examination results including a listing of indications detected
  • A discussion of any repairs to the WOL material and/or base metal and the reason for the repairs.

Entergy will also submit to the NRC a stress analysis summary demonstrating that the WOL on lSI weld N06B-KB will perform its intended design function after WOL installation. The stress analysis report will include results showing that the requirements of NB-3200 and NB-3600 of the ASME Code,Section III are satisfied. The stress analysis will also include results showing that the requirements of Subsection IWB-3000 of the ASME Code,Section XI, are satisfied. The results will show that the detected IGSCC crack including its growth in the nozzle will not adversely affect the integrity of the overlay repair. This information will be submitted to the NRC within 90 days of completing GGNS's refueling outage RF-18.

VI. CONCLUSION 10 CFR 50.55a(a)(3) states: "Proposed alternatives to the requirements of (c), (d), (e), (f), (g),

and (h) of this section or portions thereof may be used when authorized by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that:

(i) The proposed alternatives would provide an acceptable level of quality and safety, or (ii) Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety."

2 The recording criteria of the ultrasonic examination procedure to be used for the WOL examination requires that all indications, regardless of amplitude, be investigated to the extent necessary to provide accurate characterization, identity, and location. Additionally, the procedure requires that all indications, regardless of amplitude, that cannot be clearly attributed to the geometry of the overlay configuration be considered flaw indications.

3 The ultrasonic examination procedure requires that all suspected flaw indications are to be plotted on a cross-sectional drawing of the weld and that the plots should accurately identify the specific origin of the reflector.

Page 9 of 10 of GNRO-2012/00040 Relief Request 151-17 Entergy has determined that the proposed alternatives of this request provide an acceptable level of quality and safety. The proposed WOL will be installed using Nickel Alloy 52M filler metal that is resistant to IGSCC. While this is the case, the WOL is expected to create compressive residual stresses along the inside diameter of the original weld, which prevents the initiation of new IGSCC. Finally, preservice and inservice inspection of the weld overlay will be performed to ensure structural integrity is maintained. Therefore, Entergy requests that the NRC staff authorize the proposed alternative in accordance with 10 CFR 50.55a(a)(3).

VII DURATION OF PROPOSED ALTERNATIVE The proposed alternative is applicable for the life of the weld overlay associated with or on weld N06B-KB for GGNS.

Page 10 of 10

Attachment 1 To GNRO-2012100040 RHRlLPCI "C" Nozzle to Safe End Weld N06B-KB Details and Figures

GNRO-2012100040 RHRI LPCI "C" NOZZLE TO SAFE END WELD DETAILS Nozzle Nozzle Nozzle to Safe End WOL Figure 4

lSI Weld Number Material Safe End Material Material No.

Weld Material 2 N06B-KB SA-508, ENiCrFe-32 (Alloy 182) SB-166, ERNiCrFe-7, 2 Class 2 1 2 Alloy 600 3 (Alloy 52M)

ERNiCr-3 (Alloy 82)

Notes:

1. SA-508, Class 2 is P-Number 3, Group 3 low alloy steel. The grade was changed to SA-508, Grade 2 in the 1992 Edition/1994 Addenda.
2. Weld material includes weld and butter on nozzle. ENiCrFe-3 and ERNiCr-3 are F-43 nickel alloys
3. SB-166, Alloy 600 is P-Number 43 nickel alloy.
4. Weld overlay is being deposited using ERNiCrFe-7.

Page 1 of 3

GNRO-2012100040 1

Figure 1:

Detail of Weld N06B-KB with Axial Flaw Page 2 of 3

GNRO-2012100040 I

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Detail of Weld N06B-KB with WOL Page 3 of 3

Attachment 2 To GNRO-2012100040 Comparison of ASME Section XI Appendix VIII, Supplement 11 to Performance Demonstration Initiative (POI)

GNRO-2012100040 COMPARISON OF ASME SECTION XI APPENDIX VIII, SUPPLEMENT 11 TO PERFORMANCE DEMONSTRATION INITIATIVE (POI)

Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements 1.0 SPECIMEN REQUIREMENTS 1.1 General. The specimen set shall conform to the following No Change requirements.

(b) The specimen set shall consist of at least three specimens (b) The specimen set shall consist of at least three specimens having having different nominal pipe diameters and overlay thicknesses. different nominal pipe diameters and overlay thicknesses. They shall They shall include the minimum and maximum nominal pipe include the minimum and maximum nominal pipe diameters for which the diameters for which the examination procedure is applicable. Pipe examination procedure is applicable. Pipe diameters within a range of 0.9 diameters within a range of 0.9 to 1.5 times a nominal diameter to 1.5 times a nominal diameter shall be considered equivalent. If the shall be considered equivalent. If the procedure is applicable to procedure is applicable to pipe diameters of 24 in. or larger, the specimen pipe diameters of 24 in. or larger, the specimen set must include at set must include at least one specimen 24 in. or larger but need not include least one specimen 24 in. or larger but need not include the the maximum diameter. The specimen set shall include specimens with maximum diameter. The specimen set must include at least one overlays not thicker than 0.1 in. more than the minimum thickness, nor specimen with overlay thickness within -0.1 in. to +0.25 in. of the thinner than 0.25 in. of the maximum nominal overlay thickness for which maximum nominal overlay thickness for which the procedure is the examination procedure is applicable.

applicable.

Basis: To avoid confusion, the overlay thickness tolerance contained in the last sentence was reworded.

(d) Flaw Conditions (1) Base metal flaws. All flaws must be cracks in or near the butt (1) Base metal flaws. All flaws must be in or near the butt weld heat-weld heat-affected zone, open to the inside surface, and extending affected zone, open to the inside surface, and extending at least 75%

at least 75% through the base metal wall. Flaws may extend 100% through the base metal wall. Intentional overlay fabrication flaws shall not through the base metal and into the overlay material; in this case, interfere with ultrasonic detection or characterization of the base metal intentional overlay fabrication flaws shall not interfere with flaws. Specimens containing IGSCC shall be used when available. At ultrasonic detection or characterization of the cracking. Specimens least 70 percent of the flaws in the detection and sizing tests shall be containing IGSCC shall be used when available. cracks and the remainder shall be alternative flaws. Alternative flaw mechanisms, if used, shall provide crack-like reflective characteristics and shall be limited by the following:

(a) The use of Alternative flaws shall be limited to when the Page 1 of 8

G NRQ-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements implantation of cracks produces spurious reflectors that are uncharacteristic of actual flaws.

(b) Flaws shall be semi-elliptical with a tip width of less than or equal to 0.002 inches.

Basis: Paragraph 1.1 (d)(1) requires that all base metal flaws be cracks.

Implanting a crack requires excavation of the base material on at least one side of the flaw. While this may be satisfactory for ferritic materials, it does not produce a useable axial flaw in austenitic materials because the sound beam, which normally passes only through base material, must now travel through weld material on at least one side, producing an unrealistic flaw response. To resolve this issue, the POI program revised this paragraph to allow use of alternative flaw mechanisms under controlled conditions. For example, alternative flaws shall be limited to when implantation of cracks precludes obtaining an effective ultrasonic response, flaws shall be semi-elliptical with a tip width of less than or equal to 0.002 inches, and at least 70% of the flaws in the detection and sizing test shall be cracks and the remainder shall be alternative flaws.

The statement "intentional overlay fabrication flaws shall not interfere with ultrasonic detection or characterization of the base metal flaws" was included into paragraph 1.1 (d)(1). Additionally, to avoid confusion, the phrase "and the remainder shall be alternate flaws" was added to the second to last sentence of this paragraph.

Page 2 of 8

GNRO-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements (e) Detection Specimens (1) At least 20% but less than 40% of the flaws shall be oriented (1) At least 20% but less than 40% of the base metal flaws shall be within +/- 20 deg. of the pipe axial direction. The remainder shall be oriented within +/- 20 deg. of the pipe axial direction. The remainder shall be oriented circumferentially. Flaws shall not be open to any surface oriented circumferentially. Flaws shall not be open to any surface to which to which the candidate has physical or visual access. The rules of the candidate has physical or visual access.

IWA-3300 shall be used to determine whether closely spaced flaws Basis: The requirement for axially oriented overlay fabrication flaws in should be treated as single or multiple flaws.

paragraph 1.1 (e)(1) was excluded from the POI Program as an improbable scenario. Weld overlays are typically applied using automated Gas Tungsten Arc Welding techniques with the filler metal being applied in a circumferential direction. Because resultant fabrication induced discontinuities would also be expected to have major dimensions oriented in the circumferential direction axial overlay fabrication flaws are unrealistic.

The requirement for using IWA-3300 for proximity flaw evaluation in paragraph 1.1 (e)(1) was excluded, instead, indications will be sized based on their individual merits.

(2) Specimens shall be divided into base and overlay grading units. (2) Specimens shall be divided into base metal and overlay fabrication Each specimen shall contain one or both types of grading units. grading units. Each specimen shall contain one or both types of grading units. Flaws shall not interfere with ultrasonic detection or characterization of other flaws.

(a)(1) A base grading unit shall include at least 3 in. of the length of (a)(1) A base metal grading unit includes the overlay material and the outer the overlaid weld. The base grading unit includes the outer 25% of 25% of the original overlaid weld. The base metal grading unit shall extend the overlaid weld and base metal on both sides. The base grading circumferentially for at least 1 inch and shall start at the weld centerline and unit shall not include the inner 75% of the overlaid weld and base be wide enough in the axial direction to encompass one half of the original metal overlay material, or base metal-to-overlay interface. weld crown and a minimum of 0.50" of the adjacent base material.

Basis: The phrase "and base metal on both sides", was inadvertently included in the description of a base metal grading unit. The POI program intentionally excludes this requirement because some of the qualification samples include flaws on both sides of the weld. This paragraph was also modified to require that a base metal grading unit include at least 1 inch of the length of the overlaid weld, rather than 3 inches.

Page 3 of 8

GNRO-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements (a)(2) When base metal cracking penetrates into the overlay (a)(2) When base metal flaws penetrate into the overlay material, the base material, the base grading unit shall include the overlay metal within metal grading unit shall not be used as part of any overlay fabrication 1 in. of the crack location. This portion of the overlay material shall grading unit.

not be used as part of any overlay grading unit.

(a)(3) When a base grading unit is designed to be unflawed, at (a)(3) SUfficient unflawed overlaid weld and base metal shall exist on all least 1 in. of unflawed overlaid weld and base metal shall exist on sides of the grading unit to preclude interfering reflections from adjacent either side of the base grading unit. The segment of weld length flaws.

used in one base grading unit shall not be used in another base Basis: This paragraph was modified to require sufficient unflawed overlaid grading unit. Base grading units need not be uniformly spaced weld and base metal to exist on all sides of the grading unit to preclude around the specimen.

interfering reflections from adjacent flaws, rather than the 1 inch requirement.

(b)(1) An overlay grading unit shall include the overlay material and (b)(1) An overlay fabrication grading unit shall include the overlay material the base metal-to-overlay interface of at least 6 square inch. The and the base metal-to-overlay interface for a length of at least 1 inch.

overlay grading unit shall be rectangular, with minimum dimensions Basis: This paragraph was modified to define an overlay fabrication of 2 inches.

grading unit as including the overlay material and the base metal-to-overlay interface for a length of at least 1 inch, rather than the 6 square inch requirement.

(b)(2) An overlay grading unit designed to be unflawed shall be (b)(2) Overlay fabrication grading units designed to be unflawed shall be surrounded by unflawed overlay material and unflawed base metal- separated by unflawed overlay material and unflawed base metal-to-overlay to-overlay interface for at least 1 in. around its entire perimeter. interface for at least 1 inch at both ends. Sufficient unflawed overlaid weld The specific area used in one overlay grading unit shall not be used and base metal shall exist on both sides of the overlay fabrication grading in another overlay grading unit. Overlay grading units need not be unit to preclude interfering reflections from adjacent flaws. The specific spaced uniformly about the specimen. area used in one overlay fabrication grading unit shall not be used in another overlay fabrication grading unit. Overlay fabrication grading units need not be spaced uniformly about the specimen.

Basis: This paragraph states that overlay fabrication grading units designed to be unflawed shall be separated by unflawed overlay material and unflawed base metal-to-overlay interface for at least 1 inch at both ends, rather than around its entire perimeter.

Page 4 of 8

GNRO-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements (b)(3) Detection sets shall be selected from Table VIII-S2-1. The (b)(3) Detection sets shall be selected from Table VIII-S2-1. The minimum minimum detection sample set is five flawed base grading units, ten detection sample set is five flawed base metal grading units, ten unflawed unflawed base grading units, five flawed overlay grading units, and base metal grading units, five flawed overlay fabrication grading units, and ten unflawed overlay grading units. For each type of grading unit, ten unflawed overlay fabrication grading units. For each type of grading the set shall contain at least twice as many unflawed as flawed unit, the set shall contain at least twice as many unflawed as flawed grading grading units. units. For initial procedure qualification, detection sets shall include the equivalent of three personnel qualification sets. To qualify new values of essential variables, at least one personnel qualification set is required.

Basis: This paragraph states that overlay fabrication grading units designed to be unflawed shall be separated by unflawed overlay material and unflawed base metal-to-overlay interface for at least 1 inch at both ends, rather than around its entire perimeter.

(f) Sizing Specimen (1) The minimum number of flaws shall be ten. At least 30% of the (1) The minimum number of flaws shall be ten. At least 30% of the flaws flaws shall be overlay fabrication flaws. At least 40% of the flaws shall be overlay fabrication flaws. At least 40% of the flaws shall be open to shall be cracks open to the inside surface. the inside surface. SiZing sets shall contain a distribution of flaw dimensions to assess sizing capabilities. For initial procedure qualification, sizing sets shall include the equivalent of three personnel qualification sets.

To qualify new values of essential variables, at least one personnel qualification set is required.

(3) Base metal cracking used for length sizing demonstrations shall (3) Base metal flaws used for length sizing demonstrations shall be be oriented circumferentially. oriented circumferentially.

(4) Depth sizing specimen sets shall include at least two distinct (4) Depth sizing specimen sets shall include at least two distinct locations locations where cracking in the base metal extends into the overlay where a base metal flaw extends into the overlay material by at least material by at least 0.1 in. in the through-wall direction. 0.1 inch in the through-wall direction.

Page 5 of 8

GNRO-2012J00040 Appendix VIII Supplement 11: Qualification Requirements for PDI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements 2.0 CONDUCT OF PERFORMANCE DEMONSTRATION The specimen inside surface and identification shall be concealed The specimen inside surface and identification shall be concealed from the from the candidate. All examinations shall be completed prior to candidate. All examinations shall be completed prior to grading the results grading the results and presenting the results to the candidate. and presenting the results to the candidate. Divulgence of particular Divulgence of particular specimen results or candidate viewing of specimen results or candidate viewing of unmasked specimens after the unmasked specimens after the performance demonstration is performance demonstration is prohibited. The overlay fabrication flaw test prohibited. and the base metal flaw test may be performed separately.

Basis: The POI Program revised paragraph 2.0 allowing the overlay fabrication and base metal flaw tests to be performed separately.

2.1 Detection Test.

Flawed and unflawed grading units shall be randomly mixed. Flawed and unflawed grading units shall be randomly mixed. Although the Although the boundaries of specific grading units shall not be boundaries of specific grading units shall not be revealed to the candidate, revealed to the candidate, the candidate shall be made aware of the candidate shall be made aware of the type or types of grading units the type or types of grading units (base or overlay) that are present (base metal or overlay fabrication) that are present for each specimen.

for each specimen.

2.2 Length Sizing Test (d) For flaws in base grading units, the candidate shall estimate the (d) For flaws in base metal grading units, the candidate shall estimate the length of that part of the flaw that is in the outer 25% of the base length of that part of the flaw that is in the outer 25% of the base metal wall wall thickness. thickness.

Page 6 of 8

GNRO-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements 2.3 Depth Sizing Test.

For the depth sizing test, 80% of the flaws shall be sized at a (a) The depth sizing test may be conducted separately or in conjunction specific location on the surface of the specimen identified to the with the detection test.

candidate. For the remaining flaws, the regions of each specimen (b) When the depth sizing test is conducted in conjunction with the containing a flaw to be sized shall be identified to the candidate.

detection test and the detected flaws do not satisfy the requirements of The candidate shall determine the maximum depth of the flaw in 1.1 (f), additional specimens shall be provided to the candidate. The each region.

regions containing a flaw to be sized shall be identified to the candidate.

The candidate shall determine the maximum depth of the flaw in each region.

(c) For a separate depth sizing test, the regions of each specimen containing a flaw to be sized shall be identified to the candidate. The candidate shall determine the maximum depth of the flaw in each region.

3.0 ACCEPTANCE CRITERIA 3.1 Detection Acceptance Criteria.

Examination procedures, equipment, and personnel are qualified (a) Examination procedures are qualified for detection when; for detection when the results of the performance demonstration (1) All flaws within the scope of the procedure are detected and the satisfy the acceptance criteria of Table VIII-S2-1 for both detection results of the performance demonstration satisfy the acceptance criteria and false calls. The criteria shall be satisfied separately by the of Table VIII-S2-1 for false calls.

demonstration results for base grading units and for overlay grading units. (2) At least one successful personnel demonstration has been performed meeting the acceptance criteria defined in (3b).

(3) Examination equipment and personnel are qualified for detection when the results of the performance demonstration satisfy the acceptance criteria of Table VIII-S2-1 for both detection and false calls.

(4) The criteria in (2), (3) shall be satisfied separately by the demonstration results for base metal grading units and for overlay fabrication grading units.

Basis: The POI ProQram allows procedure qualification to be performed Page 7 of 8

GNRO-2012100040 Appendix VIII Supplement 11: Qualification Requirements for POI Program:

Full Structural Overlaid Wrought Austenitic Piping Welds The Proposed Alternative to Supplement 11 Requirements separately from personnel and equipment qualification. Historical data indicate that, if ultrasonic detection or sizing procedures are thoroughly tested, personnel and equipment using those procedures have a higher probability of successfully passing a qualification test. In an effort to increase the passing rate, POI has elected to perform procedure qualifications separately in order to assess and modify essential variables that may affect overall system capabilities. For a procedure to be qualified, the POI program requires three times as many flaws to be detected (or sized) as shown in Supplement 11 for the entire ultrasonic system. The personnel and equipment are still required to meet Supplement 11.

3.2 Sizing Acceptance Criteria.

(a) The RMS error of the flaw length measurements, as compared (a) The RMS error of the flaw length measurements, as compared to the to the true flaw lengths, is less than or equal to 0.75 inch. The true flaw lengths, is less than or equal to 0.75 inch. The length of base length of base metal cracking is measured at the 75% through- metal flaws is measured at the 75% through-base-metal position.

base-metal position.

(b) All extensions of base metal cracking into the overlay material This requirement is omitted.

by at least 0.1 inch. are reported as being intrusions into the overlay material. Basis: The requirement for reporting all extensions of cracking into the overlay is omitted from the POI Program because it is redundant to the RMS calculations performed in paragraph 3.2(c), and its presence adds confusion and ambiguity to depth sizing as required by paragraph 3.2(c).

This also makes the weld overlay program consistent with the Supplement 2 depth sizing criteria.

(c) The RMS error of the flaw depth measurements, as compared (b) The RMS error of the flaw depth measurements, as compared to the to the true flaw depths, is less than or equal to 0.125 inch. true flaw depths, is less than or equal to 0.125 inch.

Page 8 of 8

Enclosure 2 To GNRO-2012/00040 list of Regulatory Commitments

List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

TYPE (Check one) SCHEDULED COMPLETION COMMITMENT DATE (If Required)

ONE-TIME CONTINUING ACTION COMPLIANCE Weld overlay examination results including a listing of X 14 days after indications detected. completing the final ultrasonic examinations of the completed weld overlays Disposition of indications using the standards of ASME X 14 days after Section XI, Subsection IWB-3514-2 and/or IWB-3514-3 completing the final criteria and, if possible, the type and nature of the ultrasonic indications examinations of the completed weld overlays A discussion of any repairs to the weld overlay material X 14 days after and/or base metal and the reason for the repairs. completing the final ultrasonic examinations of the completed weld overlays Submit to the NRC a stress analysis summary X Within 90 days of demonstrating that the nozzle to safe-end DMW, N06B- completing GGNS's KB, will perform its intended design function after weld refueling outage overlay installation RF-18

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