ML072780147

Alternative Request RR-89-61, Use of Weld Overlays as an Alternative Repair and Mitigation Technique Pursuant to 10 CFR 50.55a(a)(3)(i)

ML072780147
Person / Time
Site:	Millstone
Issue date:	10/04/2007
From:	Gerald Bichof Dominion, Dominion Nuclear Connecticut
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
07-0555, RR-89-61
Download: ML072780147 (45)

Text

Dominion Nuclear Connecticut, Inc.

"1100 Dominion Boulevard, Glen Allen, Virginia 2,060 Wch Address: www.dom.com October 4, 2007 U.S. Nuclear Regulatory Commission Serial No. 07-0555 Attention: Document Control Desk NSSLIMAE R2 One White Flint North Docket No. 50-336 11555 Rockville Pike License No. DPR-65 Rockville, MD 20852-2738 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2 ALTERNATIVE REQUEST RR-89-61, USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR AND MITIGATION TECHNIQUE Pursuant to 10 CFR 50.55a(a)(3)(i) and 10 CFR 50.55a(a)(3)(ii), Dominion Nuclear Connecticut, Inc. (DNC) requests approval to use alternatives to the requirements of the ASME Code for certain repairlreplacement activities. These repair/replacement activities are related to the application of weld overlay (WOL) repairs and preemptive type weld overlay (PWOL) applications for mitigation of primary water stress corrosion cracking (PWSCC). This request is provided as an attachment to this letter and contains the descriptions of scheduled weld overlays, current ASME Code Inservice Inspection (lSI) program requirements, and the alternatives to those ASME Code requirements that are needed to support these activities. The requested alternative repair and mitigation technique provides an acceptable level of quality and safety and addresses the hardship associated with the ultrasonic test (UT) examination of austenitic cast stainless steel (CSS) material.

Approval of the proposed alternatives is requested by March 6, 2008 to support planned activities for the spring 2008 cycle 18 refueling outage.

If you have any questions regarding this submittal, please contact Margaret A. Earle at (804) 273-2768.

Sincerely, Idt1!?-:6 Gerald T. Bischof Vice President - Nuclear Engineering

Attachment:

Alternative Request RR-89-61, Use Of Weld Overlays As An Alternative Repair And Mitigation Technique

Serial No. 07-0555 Alternative Request RR-89-61 Page 2 of 2 Commitments made in this letter:

1. Limitations that result from completed weld overlay designs and UT examinations performed will be submitted to the NRC for review. The design analysis required for weld overlays will also be submitted. This information will be submitted prior to entering Mode 4 during plant startup. [See Section 4.2 of Attachment]

cc: U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406-1415 Mr. J. D. Hughey NRC Project Manager - Millstone Power Station U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 0-8 83 Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station

Serial No. 07-0555 Docket No. 50-336 ATTACHMENT ALTERNATIVE REQUEST RR-89-61, USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR AND MITIGATION TECHNIQUE MILLSTONE POWER STATION UNIT 2 DOMINION NUCLEAR CONNECTICUT, INC.

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 1 of 42 ATTACHMENT ALTERNATIVE REQUEST RR-89-61, USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR AND MITIGATION TECHNIQUE CONTENTS ACRONyMS 2 1.0 REASON FOR THE REQUEST 3 2.0 CODE COMPONENTS FOR WHICH THE ALTERNATIVE IS REQUESTED 4 3.0 CODE REQUIREMENTS FOR WHICH THE ALTERNATIVE IS REQUESTED 10 4.0 PROPOSED ALTERNATIVES AND SUPPORTING INFORMATION 11 5.0 DURATION OF THE PROPOSED REQUEST 14 6.0 PRECEDENTS 14

7.0 REFERENCES

15 8.0 CONCLUSiON 16 ATTACHMENT - FIGURES Figure 1 -Typical Weld Overlay Configuration 12 ATTACHMENT-TABLES Table 1 - Cycle 18 Welds Affected By This Alternative 6 Table 2 - Cycle 19 Welds Affected By This Alternative 7 Table 3 - Materials And Configurations For All Welds Affected By This Alternative 9 ENCLOSURE 1 Alternative Requirements For Dissimilar Metal Weld Overlays For The Use Of Alternative Request RR-89-61 17

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 2 of 42 ENCLOSURE 1 - FIGURES Fig. 1 Acceptance Examination Volume And Thickness Definitions 24 Fig.2 Preservice And Inservice Examination Volume E-F-G-H 25 Fig. 1-1 Qualification Test Plate 31 ENCLOSURE 1 - TABLES Table 1 References For Alternative Editions And Addenda Of Section XI. 32 ENCLOSURE 2 Table 1 - Modifications To ASME Code Section XI, Appendix VIII, Supplement 11 For The Use Of Alternative Request RR-89-61 33 ACYRONYMS 1 ALARA - As Low As Reasonably Achievable 2 CFR - Code Of Federal Regulations 3 CE - Combustion Engineering 4 CS - Carbon Steel 5 CSS - Cast Stainless Steel 6 DMW - Dissimilar Metal Weld 7 DNC - Dominion Nuclear Connecticut, Inc.

8 FSWOL - Full Structural Weld Overlay 9 HSS - High Safety Significant 10 lSI - Inservice Inspection 11 MPS2 - Millstone Power Station Unit 2 12 NPS - Nominal Pipe Size 13 NRC - U. S. Nuclear Regulatory Commission 14 00 - Outside Diameter 15 POI - Performance Demonstration Initiative 16 PWHT -Post Weld Heat Treatment 17 PWOL - Preemptive Weld Overlay 18 PWSCC - Primary Water Stress Corrosion Cracking 19 RCP - Reactor Coolant Pump 20 RCS - Reactor Coolant System 21 RI-ISI - Risk-Informed Inservice Inspection 22 SS - Stainless Steel 23 UT - Ultrasonic Test 24 WOL - Weld Overlay 25 25 WPS - Welding Procedure Specification

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 3 of 42 ATTACHMENT ALTERNATIVE REQUEST RR-89-61! USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR AND MITIGATION TECHNIQUE Proposed Alternative In Accordance with 10 CFR 50. 55a(a)(3)(i) and 10 CFR 50.55a(a)(3)(ii)

- Alternative Provides Acceptable Level Of Quality And Safety And Compliance With The Specified Requirements Results In A Hardship Without A Compensating Increase In The Level Of Quality And Safety -

1.0 REASON FOR THE REQUEST The ASME Code,Section XI, 1998 Edition, no Addenda, IWA-4000 (Reference 7.1), is used for the Millstone Power Station Unit 2 (MPS2)Section XI repairlreplacement program.(1) Currently, there is no comprehensive set of Code criteria addressing application of a full structural weld overlay (FSWOL) as a preemptive weld overlay (PWOL) to a dissimilar metal weld (DMW) that is constructed of Alloy 82/182 weld material. Additionally, ultrasonic test (UT) examination performance qualification requirements for DMWs made with austenitic cast stainless steel (CSS) base material are not addressed by the Code. Repairlreplacement activities associated with weld overlay (WOL) repairs or PWOL applications are required to address the materials, welding parameters, ALARA concerns, operational constraints, examination techniques, and procedure requirements for conduct of those activities.

The following documents provide a limited set of criteria needed to apply a WOL repair for unacceptable indications and installation of a PWOL for mitigation of PWSCC susceptibility in DMWs with Alloy 82/182 weld material, including the use of temper bead welding without preheat or post weld heat treatment, but they do not contain all the needed criteria.

• ASME approved Code Cases related to this topic that are listed as acceptable for use in NRC Regulatory Guide 1.147, Revision 14 (Reference 7.2). These Code Cases have the following conditions associated with their approval status:

N-504-2 (Reference 7.3): 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. (This appendix is now published in the 2005 Addenda of ASME Section XI.)

N-638-1 (Reference 7.4): UT examinations shall be demonstrated for the repaired volume using representative samples, which contain construction (1) NRC letter, "Millstone Power Station, Unit Nos. 2 and 3 RE: Request to Use 1998 Edition, with No Addenda, of ASME Section XI for Repair/Replacement Activities (TAC Nos.

MC7347and MC7348),"dated September 13,2005, (ADAMS Accession No. ML052210033).

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 4 of 42 type flaws. The acceptance criteria of NB-5330 of Section III edition and addenda approved in 10 CFR 50.55a apply to all flaws identified within the required volume.

• ASME developed and approved Code Cases that are not yet reviewed and approved by the NRC:

Code Case N-740, (Reference 7.5): This Code Case includes criteria for WOL repairs using austenitic nickel based materials.

• Code Case revisions not yet reviewed and approved by ASME or the NRC:

Code Case N-740-1: Code Case N-740 is being revised to include PWOL applications where PWOL has been defined as a mitigative weld overlay.

Code Case N-740-2: Code Case N-740 is being revised to address austenitic CSS base material.

• ASME Code 1998 Edition,Section XI.

The alternatives in this request have been developed to provide the needed criteria for performance of the weld overlay activities taking into consideration the requirements to address the materials, welding parameters, ALARA concerns, operational constraints, examination techniques, and procedure requirements for conduct of those activities.

Dominion Nuclear Connecticut, Inc. (DNC) has determined that with this comprehensive set of criteria this request can be used at MPS2 to provide an acceptable level of quality and safety in the FSWOLs as either a repair WOL or a mitigative PWOL while at the same time addressing the hardship involved with the UT examination of austenitic CSS base material.

2.0 CODE COMPONENTS FOR WHICH THE ALTERNATIVE IS REQUESTED Code components associated with this request are the high safety significant (HSS)

Class 1 piping DMWs with Alloy 82/182 weld metal that are believed to be susceptible to PWSCC and scheduled for examination in accordance with the Risk-Informed Inservice Inspection (RI-ISI) Program and the Guidelines of MRP-139 (Reference 7.6).

This request has been written to cover FSWOLs for all the MPS2 Alloy 82/182 DMWs 2-inch nominal pipe size and larger with the exception of eight 36-inch outside diameter (00) reactor coolant system (RCS) cold leg DMWs to the reactor coolant pumps (RCPs). Limited UT examination of all eight of the 36-inch cold leg welds is addressed in a separate alternative request RR-89-64.

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 5 of 42 For the upcoming cycle 18 refueling outage (2R18), 6 nozzles with HSS DMWs described in Table 1 below are currently scheduled to have full structural PWOLs applied. These nozzle welds and adjacent stainless steel safe end to elbow or pipe welds are listed in Table 1 along with any additional welds that would be required to have PWOLs or additional UT examinations added if PWSCC is found during the Post WOL UT examination.

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 6 of 42 Table 1: Cycle 18 Welds Affected By This Alternative (1)

Adjacent S Adjacent SS safe end end to elbow or end to elbow or pip d pipe weld 1----------'----

12-inch NPS RCS Hot Leg Surge Line Welds 1----------,-------------I2-inch NPS RCS Hot Leg Drain Line Weld BPS-C-1001 BPS-C-1003 BPD-C-1 001, This Weld Would Be UT Examined. Completed UT In Cycle 16 No 12-inch NPS RCS Hot Leg Shutdown Indications Of PWSCC Cooling Welds BSD-C-2001 BSD-C-2003 12-inch NPS RCS Cold Leg Safety 12-inch NPS RCS Cold Leg Safety Injection (SI) Loop 2A and Loop 1B Line Injection (SI) Loops 1A and 2B Line Welds Welds BSI-C-2001 BSI-C-2003 BSI-C-1001 BSI-C-1003 BSI-C-3000 BSI-C-3002 BSI-C-4000 BSI-C-4002 2-inch NPS RCS Cold Leg Charging Line 2-inch NPS RCS Cold Leg Charging Line Welds Welds BCH-C-1001 BCH-C-1003 BCH-C-2001 BCH-C-2003 3-inch NPS RCS Cold Leg Spray Line 2-inch RCS Cold Leg Drain Line Welds Welds BPY-C-1001 BPY-C-1003 BPD-C-1017 BPD-C-1019 BPD-C-3000 BPD-C-3002 BPD-C-2001, This Weld Would Be UT NOTE: (1) DMWs may be added from Examined.

Table 2 if time and resources become available during the 2R18 refueling 3-inch NPS RCS Cold Leg Spray Line outage to reduce the scheduled scope of Welds FSWOLs in 2R19.

BPY-C-3000 BPY-C-3002 2-inch NPS RCS Cold Leg Letdown Nozzle Weld BPD-C-4000, This Weld Would Be UT Examined. Completed UT In Cycle 16 No Indications Of PWSCC

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 7 of 42 For the cycle 19 refueling outage (2R19), the remaining 9 nozzles with HSS DMWs, described in Table 2 below, are currently scheduled to have full structural PWOLs applied. These nozzle welds and adjacent stainless steel safe end to elbow or pipe welds are listed in Table 2. No additional welds would be required to be UT examined or have PWOLs addressed if PWSCC was found during the Post WOL UT examination.

Table 2: Cycle 19 Welds Affected By This Alternative Additional Adjacent 55 safe Nozzle to safe en end end to elbow or welds pipe weld 12-inch NPS RCS Cold Leg Safety Injection (51) Loop 1A and Loop 2B Line Welds None BSI-C-1001 BSI-C-1003 BSI-C-4000 BSI-C-4002 2-inch NPS RCS Hot Leg Drain Line Welds None BPD-C-1001 BPD-C-1003 2-inch NPS RCS Cold Leg Letdown Line Welds None BPD-C-4000 BPD-C-4002 2-inch NPS RCS Cold Leg Charging Line Welds None BCH-C-2001 BCH-C-2003 3-inch NPS RCS Cold Leg Spray Line Welds None BPY-C-3000 BPY-C-3002 2-inch NPS RCS Cold Leg Drain Line Welds BPD-C-1017 BPD-C-1019 None BPD-C-3000 BPD-C-3002 BPD-C-2001 BPD-C-2003

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 8 of 42 Twelve of the fifteen MPS2 piping DMWs will not support an ASME Code Section XI, Appendix VIII, Supplement 10 (Reference 7.7), weld UT examination without extensive machining.

The performance of extensive machining to prepare these DMWs for UT examination and performing the examination will be greatly reduced with the application of a full structural PWOL. A full structural PWOL can be applied in a manner that will allow these welds to be examined following the application of the PWOL. This examination can be accomplished using the Performance Demonstration Initiative (POI) and the alternatives to ASME Code Section XI, Appendix VIII, Supplement 11 (Reference 7.8) that are described in Enclosure 2, Table 1 of this request and supplemented by the alternative requirements in Enclosure 1 that address PWOL design and examination alternatives when CSS base material is present.

2.1 Category and System Details Code Class: All listed welds are ASME Code Class 1 welds.

System Welds: Components are located in the Reactor Coolant System (RCS) pressure boundary.

Code Category: Examination Category R-A, "Risk-Informed Piping Examinations" Code Item No.: R1.15, "Elements subject to PWSCC" 2.2 Component Descriptions and Materials The materials and configuration descriptions for the 15 nozzles with DMWs that are scheduled for full structural PWOLs in the cycle 18 and 19 refueling outages are described in Table 3 below.

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 9 of 42 Table 3: Materials And Configurations For All Welds Affected By This Alternative Nozzle t Materials 12-inch NPS RCS Hot Leg Surge Line Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) Cast SS, A 351 GR II, Weld and GR CF8M, Weld is BPS-C-1001 Butter are Alloy BPS-C-1003 SS, and Elbow is 82/182, Safe End is (P-No. 8) Cast SS, (P-No. 8) Cast SS, A 351 GR CF8M A 351 GR CF8M 12-inch NPS RCS Hot Leg Shutdown Cooling Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) Cast SS, A 351 GR II, Weld and GR CF8M, Weld is BSD-C-2001 Butter are Alloy BSD-C-2003 SS, and Pipe is (P-82/182, Safe End is No.8) SS A-376 (P-No. 8) Cast SS, 316 A 351 GR CF8M 12-inch NPS RCS Cold Leg Safety Injection (SI) Loop 1A, 1B, 2A, and Loop 2B Line Welds Safe End is (P-No.

Nozzle is (P-No. 3)

8) Cast SS, A 351 Alloy Steel, BSI-C-1001 BSI-C-1 003 to (P) GR CF8M, SS A 182 F1, Weld and BSI-C-3000 BSI-C-3002 to (E) Weld, Pipe (P) is (P-Butter are Alloy BSI-C-2001 BSI-C-2003 to (P) No.8) SS A-376 82/182, Safe End is BSI-C-4000 BSI-C-4002 to (E) 316, and Elbow (E)

(P-No. 8) Cast SS, is (P-No. 8) SS A-A 351 GR CF8M 403 WP 316 2-inch NPS RCS Hot Leg Drain And Cold Leg Letdown Line Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) SS SA 182 GR II, Weld and BPD-C-1001 BPD-C-1003 TYPE 316, SS Butter are Alloy BPD-C-4000 BPD-C-4002 Weld, and Pipe is 82/182, Safe End is (P-No. 8) SS (P-No. 8) SS A-376 SA 182 TYPE 316 316

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 10 of 42 Table 3: Materials And Configurations For All Welds Affected By This Alternative Nozzle to nd Ma Materials we 3-inch NPS RCS Cold Leg Spray Line Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) SS SA 182 GR II, Weld and BPY-C-1001 BPY-C-1003 TYPE 316, SS Weld and Butter are BPY-C-3000 BPY-C-3002 Weld, and Pipe is Alloy 82/182, Safe (P-No. 8) SS A-376 End is (P-No. 8) SS 316 SA 182 TYPE 316 2-inch NPS RCS Cold Leg Drain Line Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) SS SA 182 BPD-C-1017 GR II, Weld and BPD-C-1019 TYPE 316, SS BPD-C-3000 Weld and Butter are BPD-C-3002 Weld, and Pipe is BPD-C-2001 Alloy 82/182, Safe BPD-C-2003 (P-No. 8) SS A-376 End is (P-No. 8) SS 316 SA 182 TYPE 316 2-inch NPS RCS Cold Leg Charging Line Welds Nozzle is (P-No. 1)

Safe End is (P-No.

Carbon Steel, A 105

8) SS SA 182 GR II, Weld and BCH-C-1001 BCH-C-1003 TYPE 316, SS Weld and Butter are BCH-C-2001 BCH-C-2003 Weld, and Pipe is Alloy 82/182, Safe (P-No. 8) SS A-376 End is (P-No. 8) SS 316 SA 182 TYPE 316 3.0 CODE REQUIREMENTS FOR WHICH THE ALTERNATIVE IS REQUESTED The ASME Code requirements for which the alternative is requested are contained in the following:

• ASME Code,Section XI, 1998 Edition, no Addenda, IWA-4000 (Reference 7.1)

• ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11 (Reference 7.8)

MPS2 is in its third 10-year lSI interval, which started on April 1, 1999 and has been

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 11 of 42 extended to end on March 31, 2010.(2) The 1995 Edition of Section XI with the 1996 Addenda, Appendix VIII, Supplement 10 (Reference 7.7) is used for UT examination performance demonstration requirements for dissimilar metal welds including the limitations in 10 CFR 50.55a(b), and these requirements are implemented under the industry POI.

Additionally, the requirements of 10 CFR 50.55a(g)(6)(ii)(C) apply when implementing Appendix VIII of the ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Supplement 11 (Reference 7.8). Appendix VIII of the Code contains ultrasonic examination performance qualification requirements for completed FSWOLs, is used for repair WOLs or PWOLs, and does not address UT examination when the base material is made of austenitic CSS.

4.0 PROPOSED ALTERNATIVES AND SUPPORTING INFORMATION ONC is proposing to use alternative requirements submitted in Enclosure 1 under the provisions of 10 CFR 50.55a(a)(3)(i). These alternative requirements are the result of the industry's operating experience (OE) with WOL repairs for flaws suspected or confirmed to be from PWSCC, and for the PWOLs which are being directly applied to OMWs with both austenitic stainless steel Type 308 or 309 and austenitic nickel based Alloy 52M weld material.

For all the scheduled full structural PWOLs, the potential WOL repairs, and additional PWOLs that may be applied in the case of required additional examinations, the application of this alternative request will include the adjacent stainless steel safe end-to-pipe or safe end-to-elbow welds. The general configuration of a typical WOL is depicted in Figure 1 of this section.

This alternative request will continue to be used to support implementing future phases of the control and remediation plan for the PWSCC susceptible materials at MPS2. The alternative requirements of this request will be applied for the duration of up to and including the last refueling outage of the current third 10-year lSI interval.

4.1 The Structural Weld Overlay Assembly:

The ferritic material of the nozzles is either (P-No. 1) or (P-No. 3). The safe ends and elbows are either wrought SS or CSS (P-No. 8). The pipe is wrought SS (P-No.8) material. The existing weld filler material for the PWSCC susceptible welds is Alloy 82/182 (F-No. 43 equivalent to P-No. 43).

(2) ONC letter to NRC, Millstone Units 2 & 3, Inservice Testing and Inservice Inspection Programs 10-Year Interval Changes," dated: May 3, 2007, (ADAMS Accession No.

ML071350369).

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 12 of 42 The FSWOL replaces all the structural design requirements of the pipe as if the pipe were not there. As shown in Figure 1 of this section, this WOL (weld reinforcement) will completely cover the existing Alloy 82/182 weld metal and will extend onto the ferritic and austenitic SS material on each end of the DMW, 0

including the adjacent SS weld. Although the WOL extends the full 360 around the nozzle, only half is shown in Figure 1 for clarity. In all cases under the alternative requirements of this request, a FSWOL (designed for the worst case flaw) will be applied in accordance with the alternative requirements in Enclosure 1 with a UT examination following the application of any repair WOL or PWOL.

Existing Features Pipe or Elbow (CSS) or (SS) SE/Pipe or SE/Elbow Weld (SS)

Safe End (CSS) or (SS)

Structural Nozzle/SE Weld 1'0------"

Overlay Weld (A82/182)

(A52/152)

Weld Buttering (A82/182)

Figure 1 -Typical Weld Overlay Configuration 4.2 Weld Overlay Design:

The PWOLs will be designed as FSWOLs (assumed worst case flaw) in accordance with section 2.0 of the alternative requirements of Enclosure 1. The details surrounding the design analysis for all the scheduled PWOLs are being developed to support the MPS2 cycle 18 and cycle 19 refueling outages and ONC's vendor has committed to supplying this analysis to ONC by February 28, 2008. The FSWOLs that will be applied to the DMWs at MPS2 without CSS base material will be designed for the remaining plant life. OMWs made with CSS base material will be designed for a minimum design life of 10 years and will require corresponding increased frequencies for inservice UT examination not to exceed every 10 years. As soon as this analysis is available, it will be processed and submitted for NRC review, but no later than prior to entry into Mode 4 in the startup

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 13 of 42 from the cycle 18 refueling outage (2R18).

4.3 Examinations All PWOL and WOL UT examinations will be performed to meet the alternative requirements of Enclosure 1. The UT examination, after a completed PWOL, will be performed in accordance with ASME Code Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11 (Reference 7.8) with the alternatives that are used to comply with the Performance Demonstration Initiative (POI) program, contained in Enclosure 2 and will not include any UT examination of the CSS base material because there are no current requirements for UT qualification or performance demonstration requirements that can be consistently met for this material.

4.4 Hot Cracking OE exists for hot cracking in the first layer of nickel alloy WOL deposits over stainless steel base materials. The major WOL vendors have all decided to alleviate this concern by applying austenitic SS 308 or 309 weld metal over the stainless steel base materials included in the WOL. For MPS2 there is no plan to incorporate this first layer of weld metal into the structural design thickness of the weld overlay. However, Enclosure 1 does provide criteria to allow this first layer to be used as part of the WOL with additional requirements and if this is done MPS2 will meet those requirements.

4.5 Discussion on Acceptable Level of Quality or Safety or Hardship Without A Compensating Increase in the Level of Quality or Safety 4.5.1 The use of the alternatives described in this request for the design of FSWOLs applied as either a repair WOL or a mitigative PWOL will result in an acceptable level of quality and safety for the following reasons:

• a FSWOL design does not take credit for the original DMW or SS weld and replaces all the structural design requirements of the pipe, as if the pipe were not there;

• the material used in the PWOL or the WOL is Alloy 52M filler material, which is resistant to PWSCC;

• the compressive stress created by the WOL in the underlying base material should prevent or minimize the growth of any existing flaws; and,

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 14 of 42 4.5.2 The inherent limitations associated with UT examination of CSS base material and the inability to obtain demonstration qualification of CSS as part of the required UT examination volume for PWOLs or WOL repairs is considered a hardship without a compensating increase in the level of quality or safety for the following reasons:

• OE does not indicate PWSCC would initiate in austenitic CSS material;

• the required weld and base material volume that is susceptible to PWSCC and the WOL material itself will be UT examined. This will be per the alternatives provided in Enclosure 1 with performance demonstrated UT examination in accordance with the provisions of the ASME Code Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11 with the alternatives used to comply with the POI program as shown in Enclosure 2, Table 1 excluding CSS base material.

5.0 DURATION OF THE PROPOSED REQUEST This request will be applied for the remainder of the current MPS2 third 10-year lSI interval, which is scheduled to end on March 31, 2010.

6.0 PRECEDENTS Similar requests have been submitted to address some of the issues that are contained in this request for PWOLs. However, ONC believes that it is the first Combustion Engineering (CE) plant owner to submit an alternative request that will apply over two refueling outages. Enclosures 1 and 2 of this request are similar to Enclosure 1 provided in the Millstone Power Station Unit 3 (IR-2-47, Revision 1) alternative request that was authorized by the NRC for use on May 3, 2007(3), including the POI modifications of ASME Section XI, Appendix VIII, Supplement 11 referenced in the IR 47, Revision 1 submittal. Additionally, a request was submitted by Indiana Michigan Power Company's, O. C. Cook Unit 2 for which NRC verbal approval was provided on March 23, 2006. That request included the application of full structural PWOLs to the pressurizer steam space OMWs. The NRC provided verbal approval on March 23, 2006 for a Southern California Edison, San Onofre Nuclear Generating Station (SONGS) Unit 2 request related to ultrasonic performance examination qualification of cast stainless steel under aWOL.

Additionally, the following requests associated with WOL repairs have been approved by the NRC: AmerGen Energy Company, Three Mile Island Nuclear Station, Unit 1, on (3) NRC Letter, "Safety Evaluation of Request For Approval To Use IR-2-47 For Dissimilar Metal Weld Overlays As An Alternative Repair Technique (TAC NO. MD3379)," dated:

May 3, 2007 (ADAMS Accession No. ML071210024).

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 15 of 42 July 21, 2004;(4) Constellation Energy's Calvert Cliffs Nuclear Power Plant, Unit 2, on July 20, 2005;(5) Millstone Unit 3, on January 20, 2006;(6) and Indiana Michigan Power Company, Donald C. Cook Unit 1, on February 10,2006.(7)

7.0 REFERENCES

7.1 ASME Code,Section XI, 1998 Edition, no Addenda, IWA-4000 7.2 U.S. NRC, Regulatory Guide 1.147, Revision 14, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division1, August 2005 7.3 ASME Code Case N-504-2, Alternative Rules for Repair of Class 1, 2, and 3 Austenitic Stainless Steel Piping Section XI, Division 1, March 12, 1997 7.4 ASME Code Case N-638-1, Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique Section XI, Division 1, February 13, 2003 7.5 ASME Code Case N-740, Dissimilar Metal Weld Overlay for Repair of Class 1,2, and 3 Items,Section XI, Division 1, July 14, 2006 7.6 Material Reliability Program: Primary System Piping Butt Weld Inspection and Evaluation Guideline (MRP 139), EPRI, Palo Alto, CA: 2005. 1010087 7.7 ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 10 7.8 ASME Code,Section XI, 1995 Edition with the 1996 Addenda, Appendix VIII, Supplement 11 (4) NRC letter, "Safety Evaluation of Request For Relief From Flaw Removal, Heat Treatment and Nondestructive Examination (NDE) Requirements For The Third 10-Year Inservice Inspection Interval, Three Mile Island Nuclear Station, Unit 1 (TMI-1), (TAC No. MC1201),

dated: July 21, 2004, (ADAMS Accession No. ML0416?051 0).

(5) NRC Letter, "Safety Evaluation for Calvert Cliffs Nuclear Power Plant, Unit No.2, Relief Request for Use Weld Overlay and Associated Alternative Inspection Techniques (TAC Nos.

MC6219 and MC6220), dated July 20,2005, (ADAMS Accession No. ML051930316).

(6) NRC letter, "Safety Evaluation of Relief Request IR-2-39 Pertaining to the Repair and Inspection of Nozzle to Safe End Weld, Weld No. 03-X-5641-E-T at Millstone Power Station Unit NO.3 (MPS3)," (TAC No. MC8609), dated January 20, 2006, (ADAMS Accession No.

ML053260012).

(7) NRC letter, Safety Evaluation of Alternative Request Regarding Repair of Safe-End-To-Elbow Weld 1-RC-9-01 F at the Donald C. Cook Nuclear Plant Unit 1, (TAC No. MC880?),

dated February 10, 2006, (ADAMS Accession No. ML060240355).

Serial No. 07-0555 Alternative Request RR-89-61 Attachment Page 16 of 42

8.0 CONCLUSION

The NRC has approved similar alternative requests to support application of WOLs and PWOLs to OMWs made with Alloy 82/182 weld material. The alternatives to existing ASME Code requirements that are provided in this request include consideration of available OE derived from a review of other similar requests.

Consistent with the requirements of 10 CFR 50.55a(a)(3)(i), ONC has demonstrated that the use of the alternatives described in this request for the design of FSWOLs applied as either a repair WOL or a mitigative PWOL will result in an acceptable level of quality and safety.

Consistent with the requirements of 10 CFR 50.55a(a)(3)(ii), ONC has demonstrated that the use of the alternatives described in this request in regards to the examination requirements for CSS base material will provide an acceptable alternative from Code requirements which impose undue hardship or difficulty without a compensating increase in the level of quality or safety.

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 17 of 42 ENCLOSURE 1 ALTERNATIVE REQUIREMENTS FOR DISSIMILAR METAL WELD OVERLAYS FOR THE USE OF ALTERNATIVE REQUEST RR-89-61 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 18 of 42 ALTERNATIVE REQUIREMENTS FOR DISSIMILAR METAL WELD OVERLAYS In lieu of the requirements of ASME Code Section XI, IWA-4410 and IWA-4611, a defect in austenitic stainless steel or austenitic nickel alloy piping, components, or associated welds may be reduced to a flaw of acceptable size in accordance with IWB-3640 by addition of a repair weld overlay. The repair weld overlay is in lieu of the requirements of IWA-4410, and a mitigative weld overlay may be applied. All ASME Code references are to the 2004 Edition with the 2006 Addenda. Refer to Table 1 for the use of these alternative requirements with other Editions and Addenda. The weld overlay shall be applied by deposition of weld reinforcement (weld overlay) on the outside surface of the piping, component, or associated weld, including ferritic materials when necessary, provided the following requirements are met:

1 GENERAL REQUIREMENTS Full Structural Weld Overlay - Deposition of weld reinforcement on the outside diameter of the piping, component, or associated weld, such that the weld reinforcement is capable of supporting the design loads, without consideration of the piping, component, or associated weld beneath the weld reinforcement. Full structural weld overlay can either be a mitigative or repair weld overlay as defined below:

Mitigative Weld Overlay - Weld overlay that is applied over material with no inside surface planar defects, prior to the weld overlay being applied.

Repair Weld Overlay - Weld overlay that is applied over material with a defect, or where a pre-weld overlay exam is not performed.

(a) A full-structural weld overlay shall be applied by deposition of weld reinforcement (weld overlay) on the outside surface of circumferential welds between items, inclusive of the UNS N06082 or W86182 welds that join the two items. The design of the overlay may be extended to include the adjacent stainless steel to stainless steel welds (P-No. 8 to P-No. 8).

(b) This alternative applies to dissimilar metal welds between P-No. 8 or 43 and P-Nos.

1, 3, 12A, 128, or 12C(1) materials. This alternative also applies to dissimilar metal welds between P-No. 8 and P-No. 43 materials joined with austenitic F-No. 43 filler metal, and to welds between P-No. 8 and P-No. 8 materials as described in 1(a).

(c) Weld overlay filler metal shall be austenitic stainless steel meeting the requirements of (e) (1) below or nickel alloy (28% Cr min., ERNiCrFe-7 or ERNiCrFe-7A) meeting the requirements of (e) (2) below applied 360 deg around the circumference of the (1) P-Nos. 12A, 128, and 12C designations refer to specific material classifications originally identified in Section III and subsequently reclassified in a later Edition of Section IX. Welds between P-No. 8 or P-No. 43 materials joined with an austenitic filler material.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 19 of 42 item and deposited using a Welding Procedure Specification (WPS) for groove welding, qualified in accordance with the Construction Code and Owner's Requirements and identified in the Repair/Replacement Plan. As an alternative to the post weld heat treatment (PWHT) requirements of the Construction Code and Owner's requirements, the following provisions may be applied.

(1) For P-No. 1 base materials, the Construction Code PWHT exemptions permitted for circumferential butt welds may be applied to exempt the weld overlay from PWHT with the following clarifications:

(a) The nominal weld thickness is defined as the maximum overlay thickness applied over the ferritic base material.

(b) The base material thickness is defined as the maximum thickness of the ferritic material where the overlay is applied.

(2) Appendix I may be used for ambient-temperature temper bead welding.

(d) Prior to deposition of the weld overlay, the surface to be weld overlaid shall be examined using the liquid penetrant method. Indications with major dimensions greater than V16 in. (1.5 mm) shall be removed, reduced in size, or weld repaired in accordance with the following requirements:

(1) For weld repair, one or more layers of weld metal shall be applied to seal unacceptable indications in the area to be repaired with or without excavation. The thickness of these layers shall not be used in meeting weld reinforcement design thickness requirements. Peening the unacceptable indication prior to welding is permitted.

(2) If weld repair of indications identified in 1(d) is required, the area where the weld overlay is to be deposited, including any local weld repairs or initial weld overlay layer, shall be examined using the liquid penetrant method. The area shall contain no indications with major dimensions greater than V16 in.

(1.5 mm) prior to the application of the structural layers of the weld overlay.

(3) In order to reduce the risk of cracks when applying an austenitic nickel alloy over P-No. 8 base metal it is permissible to apply a layer of austenitic stainless steel filler material over the austenitic base metal. The thickness of these layers shall not be used in meeting weld reinforcement design thickness requirements.

(e) Weld overlay deposits shall meet the following requirements:

(1) The austenitic stainless steel weld reinforcement shall consist of at least two weld layers having as-deposited delta ferrite content of at least 7.5 Ferrite Number (FN). The first layer of weld metal with delta ferrite content of at least 7.5 FN shall constitute the first layer of the weld reinforcement that may be credited toward the required thickness. Alternatively, first layers of at least 5 FN are acceptable, provided the carbon content of the deposited weld metal is determined by chemical analysis to be less than 0.02%.

(2) The austenitic nickel alloy weld overlay shall consist of at least two weld layers deposited using a filler material with a Cr content of at least 28%. The

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 20 of 42 first layer of weld metal deposited may not be credited toward the required thickness. Alternatively, a first diluted layer may be credited toward the required thickness, provided the portion of the layer over the austenitic base material, austenitic filler material weld, and the associated dilution zone from an adjacent ferritic base material contain at least 24% Cr, and the Cr content of the deposited weld metal is determined by chemical analysis of the production weld or of a representative coupon taken from a mockup prepared in accordance with the WPS for the production weld.

(f) This alternative is only for welding in applications predicted not to have exceeded thermal neutron (E < 0.5 eV) fluence of 1 x 1017 neutrons per cm 2 prior to welding.

(g) A new weld overlay shall not be installed over the top of an existing weld overlay that has been in service.

2 CRACK GROWTH AND DESIGN (a) Crack Growth Calculation of Flaws in the Original Weld or Base Metal- The size of all flaws detected or postulated in the original weld or base metal shall be used to define the life of the overlay. In no case shall the inspection interval be longer than the life of the overlay. The inspection interval shall be as specified in 3(c). Crack growth in the original weld or base metal, due to both stress corrosion and fatigue, shall be evaluated. Flaw characterization and evaluation shall be based on the examination results, as described below. If the flaw is at or near the boundary of two different materials, evaluation of flaw growth in both materials is required.

(1) For repair overlays, the initial flaw size for crack growth shall be based on the as-found flaw or postulated flaw, if no pre-overlay examination is performed.

(2) For postulated flaws, the axial flaw length shall be set at 1.5 in. (38 mm) or the combined width of the weld plus buttering, whichever is greater. The circumferential flaw length shall be assumed to be 360 deg.

(3) If an examination is performed prior to application of the overlay, which is qualified in accordance with ASME Code Section XI Appendix VIII, Supplement 10 or Supplement 2 as applicable, and no inside-surface-connected planar flaws are discovered, and surface examination is acceptable, initial flaws originated from the inside surface of the weldment equal to 10% of the original wall thickness shall be assumed in both the axial and circumferential directions, and the overlay shall be considered mitigative.

(4) If an Appendix VIII, Supplement 10 or Supplement 2 as applicable, ultrasonic examination is not performed prior to application of the overlay, initial inside-surface-connected planar flaws equal to at least 75% through the original wall thickness shall be assumed, in both the axial and circumferential directions, consistent with the overlay examination volume in Fig. 2, and the overlay shall be considered a repair. For austenitic cast stainless steel components, initial inside-surface-connected planar flaws equal to 75% of the original wall

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 21 of 42 thickness shall be assumed provided 90% of the examination volume, as defined in Fig. 2, is obtained. If 90% coverage is not obtained, a 100% through wall flaw shall be assumed.

(5) There may be circumstances in which an overlay examination is performed using an ultrasonic examination procedure qualified in accordance with Appendix VIII, Supplement 11 for depths greater than the outer 25% of the original wall thickness (Fig. 2). For such cases, initial flaw depths shall be assumed to be the detected depth consistent with the depth to which the examination procedure is qualified, plus the postulated worst-case flaw in the inner region of the pipe wall thickness that is not UT qualified.

(6) In determining the expected life of the overlay, any planar flaw found by the overlay preservice inspection of 3(b) that exceeds the depth of (3), (4) or (5) above shall be used as part of the initial flaw depth. The initial flaw depth assumed is the detected flaw depth plus the postulated worst-case flaw depth in the UT-unqualified region of the pipe wall thickness. An overlay meeting this condition shall be considered a repair.

(b) Structural Design and Sizing of the Overlay - The design of the weld overlay shall satisfy the following, using the assumptions and flaw characterization restrictions in 2(a). The following design analysis shall be completed in accordance with IWA-4311:

(1) The axial length and end slope of the weld overlay shall cover the weld and heat-affected zones on each side of the weld and provide for load redistribution from the item into the weld overlay and back into the item without violating applicable stress limits of NB-3200 or the Construction Code. Any laminar flaws in the weld overlay shall be evaluated in the analysis to ensure that load redistribution complies with the above. These requirements will usually be satisfied if the weld overlay full-thickness length extends axially beyond the projected flaw by at least 0.75~, where R is the outer radius of the item and t is the nominal wall thickness of the item.

(2) Unless specifically analyzed in accordance with 2(b)(1), the end transition slope of the overlay shall not exceed 30 deg. with the nozzle/pipe axis. A taper of not more than 1:3 is recommended.

(3) For determining the combined length of circumferentially oriented flaws in the underlying base material or weld, multiple flaws shall be treated as one flaw of length equal to the sum of the lengths of the individual flaws characterized in accordance with IWA-3300.

(4) For circumferentially oriented flaws, in the underlying base material or weld, the flaws shall be assumed to be 100% through the original wall thickness for the entire circumference.

(5) For axial flaws in the underlying base material or weld, the flaws shall be assumed to be 100% through the original wall thickness of the item for the entire axial length of the flaw or combined flaws, as applicable, for the entire circumference.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 22 of 42 (6) For mitigative full structural overlays, the assumed flaw in the underlying base material or weld shall be based on the limiting case of (a) or (b) below:

(a) 100% through-wall for the entire circumference (b) 100% through-wall for 1.5 in. (38 mm) or the combined width of the weld plus buttering, whichever is greater, in the axial direction for the entire circumference (7) The overlay design thickness shall be verified using only the weld overlay thickness conforming to the deposit analysis requirements of 1(e). The combined wall thickness at the weld overlay, or any postulated worst-case planar flaws under the laminar flaws in the weld overlay, and the effects of any discontinuities (e.g., another weld overlay or reinforcement for a branch connection) within a distance of 2.5\,!Ri from the toes of the weld overlay, including the flaw size assumptions defined in 2(b)(4), (5), or (6) above, shall be evaluated and meet the requirements of IWB-3640, IWC-3640, or IWD-3640, as applicable. Ultrasonic examination procedures and personnel used to perform ultrasonic examinations prior to weld overlay application shall be qualified in accordance with Appendix VIII, Supplement 10.

(8) The effects of any changes in applied loads, as a result of weld shrinkage from the entire overlay, on other items in the piping system (e.g., support loads and clearances, nozzle loads, and changes in system flexibility and weight due to the weld overlay) shall be evaluated. Existing flaws previously accepted by analytical evaluation shall be evaluated in accordance with IWB-3640, IWC-3640, or IWD-3640, as applicable.

3 EXAMINATION In lieu of all other examination requirements, the examination requirements of this alternative shall be met. Nondestructive examination methods shall be in accordance with IWA-2200, except as specified herein. Nondestructive examination personnel shall be qualified in accordance with IWA-2300. Ultrasonic examination procedures and personnel shall be qualified in accordance with Appendix VIII, Supplement 11.

For cast stainless steel components for which no supplement is available in Appendix VIII, the weld volume shall be examined by Appendix VIII procedures to the maximum extent practicable and the remaining volume may be examined using Appendix III.

(a) Acceptance Examination (1) The weld overlay shall have a surface finish of 250 lJin. (6.3 IJm) RMS or better and contour that permits ultrasonic examination in accordance with procedures qualified in accordance with Appendix VIII. The weld overlay shall be inspected to verify acceptable configuration.

(2) The weld overlay and the adjacent base material for at least 112 in. (13 mm) from each side of the overlay shall be examined using the liquid penetrant

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 23 of 42 method. The weld overlay shall satisfy the surface examination acceptance criteria for welds of the Construction Code or NB-5300. The adjacent base metal shall satisfy the surface examination acceptance criteria for base material of the Construction Code or NB-2500. If ambient-temperature temper bead welding is performed, the liquid penetrant examination of the completed weld overlay shall be conducted at least 48 hrs following completion of the three tempering layers over the ferritic steel.

(3) The acceptance examination volume A-B-C-D in Fig. 1(a) shall be ultrasonically examined to assure adequate fusion (i.e., adequate bond) with the base metal and to detect welding flaws, such as interbead lack of fusion, inclusions, or cracks. The interface C-D shown between the overlay and the weld includes the bond and heat affected zone from the overlay. If ambient-temperature temper bead welding is performed, the ultrasonic examination of the completed weld overlay shall be conducted at least 48 hrs after completion of the three tempering layers over the ferritic steel.

(a) Planar flaws detected in the weld overlay acceptance examination shall meet the preservice examination standards of Table IWB-3514-2. In applying the acceptance standards to planar indications, the thickness t1.

t2. or b defined in Fig. 1(b) shall be used as the nominal wall thickness in Table IWB-3514-2, provided the base metal beneath the flaw (Le., safe end, nozzle, or piping material) is not susceptible to stress corrosion cracking (SCC). For susceptible material, t1 shall be used.

(b) Laminar flaws detected in the weld overlay shall meet the following requirements:

1. The acceptance standards of Table IWB-3514-3 shall be met, with the additional limitations that the total laminar flaw shall not exceed 10%

of the weld surface area, and that no linear dimension of the laminar flaw area exceed the greater of 3 in. (76 mm) or 10 % of the nominal pipe circumference.

2. For examination volume A-B-C-D in Fig. 1(a), the reduction in coverage due to laminar flaws shall be less than 10%. The uninspectable volume is the volume in the weld overlay underneath the laminar flaws for which coverage cannot be achieved using the angle beam examination method.

3. Any uninspectable volume in the weld overlay shall be assumed to contain the largest radial planar flaw that could exist within that volume. This assumed flaw shall meet the preservice examination acceptance standards of Table IWB-3514-2, with nominal wall thickness as defined above for planar flaws. Alternatively, the assumed flaw shall be evaluated and shall meet the requirements of IWB-3640, IWC-3640, or IWD-3640, as applicable. Both axial and circumferential planar flaws shall be assumed.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 24 of 42 (4) After completion of all welding activities, VT-3 visual examination shall be performed on affected restraints, supports, and snubbers, to verify that their operability and functional adequacy have not been adversely affected.

A a Examination Volume A-S-e-O Notes:

(1) b is equivalent to the nominal thickness of nozzle or pipe being overlaid.

(2) x is the distance from the weld fusion line or maximum axial extent of the flaw being overlaid to the nearest location of the overlay flaw being evaluated.

(3) The nominal wall thickness is t1 for flaws in E-F-G-H, t2 for flaws in K-M-N-L or O-J-I-P, or b for flaws in F-K-L-G or J-E-H-1. For x < b, t3 = t 1 + (x / b)(h -

t1).

(4) The weld includes the nozzle or safe end butter, where applied.

FIG. 1 ACCEPTANCE EXAMINATION VOLUME AND THICKNESS DEFINITIONS (b) Preservice Inspection (1) The examination volume in Fig. 2 shall be ultrasonically examined. The angle beam shall be directed perpendicular and parallel to the piping axis, with scanning performed in four directions, to locate and size any planar flaws that

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 25 of 42 might have propagated into the outer 25% of the base material or into the weld overlay. For weld overlays with cast austenitic stainless steel base materials only planar flaws that might have propagated into the weld overlay are required to be located and sized.

(2) The preservice examination acceptance standards of Table IWB-3514-2 shall be met for the weld overlay. In applying the acceptance standards, wall thickness, tw , shall be the thickness of the weld overlay. Planar flaws in the outer 25% of the base metal thickness shall meet the design analysis requirements of 2(b).

(3) The flaw evaluation requirements of IWB-3640, IWC-3640, or IWD-3640 shall not be applied to planar flaws identified during preservice examination that exceed the preservice examination acceptance standards of Table IWB-3514-2.

(UJID) l.tin.. *_ U fMift."

t t

~----....,,-- J Examination Volume A-B-C-D Notes:

(1) For axial or circumferential flaws, the axial extent of the examination volume shall extend at least 'V2 in. (13 mm) beyond the as-found flaw and at least 112 in. (13 mm) beyond the toes of the original weld, including weld end butter, where applied.

(2) The weld includes the nozzle or safe end butter, where applied.

FIG. 2 PRESERVICE AND INSERVICE EXAMINATION VOLUME E-F-G-H (c) Inservice Inspection (1) The weld overlay examination shall be added to the inspection plan. The weld overlay inspection interval shall not be greater than the life of the overlay as determined in 2(a) above. All weld overlays shall be examined prior to the end of their design life.

(2) The weld overlay shall be ultrasonically examined during the first or second refueling outage following application. Alternatively, for mitigative weld overlays,

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 26 of 42 in which pre-overlay examinations are performed in accordance with 2(a)(3),

post-overlay examinations are performed in accordance with 3(a) and 3(b) and no inside-surface-connected planar flaws are discovered, the overlay may be placed immediately into the population to be examined in accordance with 3(c)(5).

(3) The weld overlay examination volume in Fig. 2 shall be ultrasonically examined to determine if any new or eXisting planar flaws have propagated into the outer 25% of the base metal thickness or into the overlay. The angle beam shall be directed perpendicular and parallel to the piping axis, with scanning performed in four directions.

(4) The weld overlay shall meet the inservice examination acceptance standards of Table IWB-3514-2. If the acceptance standards of Table IWB-3514-2 cannot be met, the weld overlay shall meet the acceptance standards of IWB-3600, IWC-3600, or IWD-3600, as applicable. Planar flaws in the outer 25% of the base metal thickness shall meet the design analysis requirements of Paragraph 2(b).

Any stress corrosion cracking in the weld overlay material is unacceptable. Any indication that is characterized as stress corrosion cracking in the weld overlay material is unacceptable.

(5) Weld overlay examination volumes in Fig. 2 that show no indication of planar flaw growth or new planar flaws shall be placed into a population to be examined on a sample basis, except as required by 3(c)(1). Twenty-five percent of this population shall be examined at least once during each inspection interval.

(6) If inservice examinations reveal planar flaw crack growth, or new planar flaws that meet the acceptance standards of IWB-3514, IWB-3600, IWC-3600, or IWD-3600, the weld overlay examination volume shall be reexamined during the first or second refueling outage following discovery of the growth or new flaws.

(7) For weld overlay examination volumes with unacceptable indications in accordance with 3(c)(4), the weld overlay and original defective weld shall be removed. A repair/replacement activity shall be performed in accordance with IWA-4000.

(d) Additional Examinations If inservice examinations reveal a defect, in accordance with 3(c)(4), planar flaw growth into the weld overlay design thickness, or axial flaw growth beyond the specified examination volume, additional weld overlay examination volumes, equal to the number scheduled for the current inspection period, shall be examined prior to return to service. If additional defects are found in the second sample, 50% of the total population of weld overlay examination volumes shall be examined prior to return to service. If additional defects are found, the entire remaining population of weld overlay examination volumes shall be examined prior to return to service.

4 PRESSURE TESTING A system leakage test shall be performed in accordance with IWA-5000.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 27 of 42 5 DOCUMENTATION Use of this alternative shall be documented on Form NIS-2A.

MANDArORY APPENDIX I AMBIENT TEMPERATURE TEMPER BEAD WELDING 1-1 GENIERAL REQUIREMENTS (a) This appendix applies to dissimilar austenitic filler metal welds between P-No. 1, 3, 12A,12B, and 12C materials and their associated welds and welds joining P-No. 8 1

or 43 materials to P-No. 1, 3, 12A, 12B, and 12d ) materials with the following limitation: This Appendix shall not be used to repair SA-302 Grade B material unless the material has been modified to include from 0.4% to 1.0% nickel, quenching and tempering, and application of a fine grain melting practice.

(b) The maximum area of an individual weld overlay based on the finished surface over the ferritic base material shall be 500 sq. in. (325,000 sq. mm).

(c) Repairlreplacement activities on a dissimilar-metal weld in accordance with this Appendix are limited to those along the fusion line of a nonferritic weld to ferritic base material on which 1/8 in. (3 mm), or less of nonferritic weld deposit exists abOVE! the original fusion line.

(d) If a defect penetrates into the ferritic base material, repair of the base material, using a nonferritic weld filler material, may be performed in accordance with this Appendix, provided the depth of repair in the base material does not exceed 3/8 in.

(10mrn).

(e) Prior to welding the area to be welded and a band around the area of at least 1-1/2 times the component thickness or 5 in. (130 mm), whichever is less, shall be at least ~50°F (10°C).

(f) Weldil1g materials shall meet the Owner's Requirements and the Construction Code and Cases or NRC approved alternative requests specified in the Repair/Replacement Plan. Welding materials shall be controlled so that they are identified as acceptable until consumed.

(g) Peening may be used, except on the initial and final layers.

1-2 WELDING QUALIFICATIONS The welding procedures and the welding operators shall be qualified in accordance with Section IX and the requirements of 1-1 and 1-2.

1-2.1 Procedure Qualification (a) The base materials for the welding procedure qualification shall be of the same P-Numher and Group Number as the materials to be welded. The materials shall be

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 28 of 42 postvveld heat treated to at least the time and temperature that was applied to the materials being welded.

(b) The root width and included angle of the cavity in the test assembly shall be no greatE3r than the minimum specified for the repair.

(c) The maximum interpass temperature for the first three layers of the test assembly shall be 150°F (66°C).

(d) The tl~st assembly cavity depth shall be at least 1 in. (25 mm). The test assembly thickness shall be at least twice the test assembly cavity depth. The test assembly shall be large enough to permit removal of the required test specimens. The test assembly dimensions surrounding the cavity shall be at least the test assembly thickness and at least 6 in. (150 mm). The qualification test plate shall be prepared in accordance with Fig. 1-1.

(e) Ferritic base material for the procedure qualification test shall meet the impact test requirements of the Construction Code and Owner's Requirements. If such requirements are not in the Construction Code and Owner's Requirements, the impact properties shall be determined by Charpy V-notch impact tests of the procedure qualification base material at or below the lowest service temperature of the itE~m to be repaired. The location and orientation of the test specimens shall be similar to those required in 1-1 (f) below, but shall be in the base metal.

(f) Charpy V-notch tests of the ferritic heat-affected zone (HAl) shall be performed at the same temperature as the base metal test of 1-1 (e) above. Number, location, and orientation of test specimens shall be as follows:

(1) The specimens shall be removed from a location as near as practical to a depth of one-half the thickness of the deposited weld metal. The coupons for HAl impact specimens shall be taken transverse to the axis of the weld and etched to define the HAl. The notch of the Charpy V-notch specimen shall be cut approximately normal to the material surface in such a manner as to include as much HAl as possible in the resulting fracture. When the material thickness permits, the axis of a specimen shall be inclined to allow the root of the notch to be aligned parallel to the fusion line.

(2) If the test material is in the form of a plate or a forging, the axis of the weld shall be oriented parallel to the principal direction of rolling or forging.

(g) The Charpy V-notch test shall be performed in accordance with SA-370. Specimens shall be in accordance with SA-370, Fig. 11, Type A. The test shall consist of a set of three full-size 10 mm X 10 mm specimens. The lateral expansion, percent shear, absorbed energy, test temperature, orientation and location of all test specimens shall be reported in the Procedure Qualification Record.

(h) The average lateral expansion value of the three HAl Charpy V-notch specimens shall be equal to or greater than the average lateral expansion value of the three unaffeded base metal specimens. However, if the average lateral expansion value of the' HAl Charpy V-notch specimens is less than the average value for the unaffected base metal specimens and the procedure qualification meets all other requin~ments of this appendix, either of the following shall be performed:

(1) The welding procedure shall be requalified.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 29 of 42 (2) An Adjustment Temperature for the procedure qualification shall be determined in accordance with the applicable provisions of NB-4335.2 of Section III, 2001 Edition with the 2002 Addenda. The RT NDT or lowest service temperature of the materials for which the welding procedure will be used shall be increased by a temperature equivalent to that of the Adjustment Temperature.

1-2.2 Pelformance Qualification Welding operators shall be qualified in accordance with Section IX.

1-3 WELIDING PROCEDURE REQUIREMENTS The welding procedure shall include the following requirements:

(a) The weld metal shall be deposited by the automatic or machine GTAW process.

(b) Dissimilar metal welds shall be made using A-No.8 weld metal (QW-442) for P-No.

8 to P-No. 1, 3, or 12 (A, B, or C) weld joints or F-No. 43 weld metal (QW-432) for P-No. 8 or 43 to P-No. 1, 3, or 12 (A, B, or C) weld joints.

(c) The aJea to be welded shall be buttered with a deposit of at least three layers to achieve at least 1/8 in. (3mm) overlay thickness with the heat input for each layer controlled to within +/-10% of that used in the procedure qualification test. The heat input of the first three layers shall not exceed 45kJ/in. (1.8 kJ/mm) under any conditions. Particular care shall be taken in the placement of the weld layers of the austenitic overlay filler material at the toe of the overlay to ensure that the HAl and ferritic: base metal are tempered. Subsequent layers shall be deposited with a heat input not exceeding that used for layers beyond the third layer in the procedure qualification.

(d) The maximum interpass temperature for field applications shall be 350°F (180°C) for all weld layers regardless of the interpass temperature used during qualification.

The interpass temperature limitation of QW-406.3 need not be applied.

(e) The interpass temperature shall be determined by:

(1) Temperature measurement (e.g. pyrometers, temperature indicating crayons, thermocouples) during welding. When it is impractical to use interpass temperature measurements described in this paragraph due to situations where the weldment area is not accessible, such as internal bore welding or when there are extenuating radiological concerns, either paragraph 3(e)(2) or paragraph 3(e)(3) may be used.

(2) Heat flow calculations using the variables listed below as a minimum:

(i) welding heat input (ii) initial base material temperature (iii) configuration, thickness, and mass of the item being welded (iv) thermal conductivity and diffusivity of the materials being welded (v) arc time per weld pass and delay time between each pass (Vi) arc time to complete the weld

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 30 of 42 (3) Measurement of the maximum interpass temperature on a test coupon that is equal to or less than the thickness of the item to be welded. The maximum heat input of the welding procedure shall be used in the welding of the test coupon.

(f) Particular care shall be given to ensure that the weld region is free of all potential sources of hydrogen. The surfaces to be welded, filler metal and shielding gas shall be suitably controlled.

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 31 of 42 Discard HA2Charpy V,.Noteh Trlnsverse Sidl Send Weld metal Heat affected tOAe (HM~

GENERAL NOTE: Base metal Charpy impact specimens are not shown.

FIG. 1-1 QUALIFICATION TEST PLATE

Serial No. 07-0555 Docket No. 50-336 Alternative Request RR-89-61 Enclosure 1 to Attachment Page 32 of 42 r-----. ...-

TABLE 1 REFERENCES FOR ALTERNATIVE EDITIONS AND ADDENDA OF SECTION XI ition with ddenda through 1989 Edition with 1990 Addenda IWA-4000 IWA-4000 IWA-4000 IWA-4000 IWA-4000 & IWA-Repair/Replacement 7000 Activities IWA-4311 IWA-4311 IWA-4311 NA NA Configuration Chan es IWA-4410 Welding, IWA-4410 IWA-4410 IWA-4170 IWA-4120 Brazing, Metal Removal, and Installation - General Re uirements IWA-3300 Flaw IWA-3300 IWA-3300 IWA-3300 IWA-3300 Characterization IWA-4611 Defect IWA-4611 IWA-4421 & IWA-4170(b) IWA-4120 Removal IWA-4424 IWB-3514 Standards IWB-3514 IWB-3514 IWB-3514 IWB-3514 for Cate 0 B-F IWB/C/D -3600 IWB/C-3600 IWB/C-3600 IWB/C-3600 IWB/C-3600 Anal tical Evaluation IWB/C/D-3640 IWB/C-3640 or IWB/C-3640 or IWB/C-3640 or IWB/C-3640 Evaluation IWB/C-3650 IWB/C-3650 IWB/C-3650*

Procedures

• Starting with the 1989 Edition with the 1989 Addenda

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 33 of 42 ENCLOSURE 2 TABLE 1- MODIFICATIONS TO ASME CODE, SECTION XI, APPENDIX VIII, SUPPLEMENT 11 FOR THE USE OF ALTERNATIVE REQUEST RR-89-61 DOMINION NUCLEAR CONNECTICUT, INC.

MILLSTONE POWER STATION UNIT 2

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 34 of 42 Appendix VIII of ASME Code Section XI cannot be used directly for NDE of a structural weld overlay repair. Additionally, the qualification requirements including those in Appendix VIII and with the alternatives provided below do not address austenitic CSS materials, but they do cover the other materials included in the design of the MPS2 dissimilar metal welds. Therefore, this alternative is proposed as part of this request to use the POI program implementation of Appendix VIII with the detailed comparison of Appendix VIII and POI requirements summarized below.

The alternative requested allows closer spacing of flaws provided they don't interfere with detection or discrimination. The specimens used to date for qualification to the tri-party (NRC/BWROG/EPRI) agreement have a flaw population density greater than allowed by current Code requirements. These samples have been used successfully for all previous qualifications under the tri-party agreement program. To facilitate their use and provide continuity from the tri-party agreement program to Supplement 11, the POI program has merged the tri-party test specimens into their weld overlay program with the following alternatives.

Table 1 Alternatives to Appendix VIII, Supplement 11 OGRAM:

Alte ive to Req ements 1.0 SPECIMEN REQUIREMENTS 1.1 General. The specimen set shall conform to the following requirements.

(b) The specimen set shall consist of at least Alternative: (b) The specimen set shall three specimens having different nominal pipe include specimens with overlays not thicker diameters and overlay thicknesses. They shall than 0.1 in. more than the minimum thickness, include the minimum and maximum nominal nor thinner than 0.25 in. of the maximum pipe diameters for which the examination nominal overlay thickness for which the procedure is applicable. Pipe diameters within examination procedure is applicable.

a range of 0.9 to 1.5 times a nominal diameter Basis: To avoid confusion, the overlay shall be considered equivalent. If the thickness tolerance contained in the last procedure is applicable to pipe diameters of 24 sentence was reworded and the phrase "and in. or larger, the specimen set must include at the remainder shall be alternative flaws" was least one specimen 24 in. or larger but need added to the next to last sentence in not include the maximum diameter. The paragraph 1. 1(d)(1).

specimen set must include at least one specimen with overlay thickness within -0.1 in.

to +0.25 in. of the maximum nominal overlay thickness for which the procedure is applicable.

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 35 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 PROGRAM:

ternative to equirements (d) Flaw Conditions (1) Base metal flaws. All flaws must be cracks Alternative: (1) ... must be in or... intentional in or near the butt weld heat-affected zone, overlay fabrication flaws shall not interfere with open to the inside surface, and extending at ultrasonic detection or characterization of the least 75% through the base metal wall. Flaws base metal flaws. Specimens containing may extend 100% through the base metal and intergranular stress corrosion cracking shall be into the overlay material; in this case, used when available. At least 70% of the intentional overlay fabrication flaws shall not flaws in the detection and sizing tests shall be interfere with ultrasonic detection or cracks and the remainder shall be alternative characterization of the cracking. Specimens flaws. Alternative flaw mechanisms, if used, containing IGSCC shall be used when shall provide crack-like reflective available. characteristics and shall be limited by the following:

(a) The use of alternative flaws shall be limited to when the 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: This paragraph 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.

To avoid confusion, the overla thickness

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 36 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 AM:

RE rnative to OV equirements tolerance contained in paragraph 1. 1(b) last sentence, was reworded and the phrase "and the remainder shall be alternative flaws" was added to the next to last sentence.

Paragraph 1. 1(d)(1) includes the statement that intentional overlay fabrication flaws shall not interfere with ultrasonic detection or characterization of the base metal flaws.

(e) Detection Specimens (1) At least 20% but less than 40% of the flaws Alternative: (1) At least 20% but less than shall be oriented within .:t.20° of the pipe axial 40% of the base metal flaws shall be oriented direction. The remainder shall be oriented within :t.20° of the pipe axial direction. The circumferentially. Flaws shall not be open to remainder shall be oriented circumferentially.

any surface to which the candidate has Flaws shall not be open to any surface to physical or visual access. The rules of IWA- which the candidate has physical or visual 3300 shall be used to determine whether access.

closely spaced flaws should be treated as Basis: The requirement for axially oriented single or multiple flaws. overlay fabrication flaws was excluded from the POI Program as an improbable scenario.

Weld overlays are typically applied using automated GTAW techniques with the filler metal 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 was excluded, instead indications will be sized based on their individual merits

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 37 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 POI PRO M:

osed AI e ative to t 11 Requirements (2) Specimens shall be divided into base and Alternative: (2) Specimens shall be divided overlay grading units. Each specimen shall into base metal and overlay fabrication 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 Alternative: (a)(1) A base metal grading unit 3 in. of the length of the overlaid weld. The includes the overlay material and the outer base grading unit includes the outer 25% of 25% of the original overlaid weld. The base the overlaid weld and base metal on both metal grading unit shall extend sides. The base grading unit shall not include circumferentially for at least 1 in. and shall the inner 75% of the overlaid weld and base start at the weld centerline and be wide metal overlay material, or base metal-to- enough in the axial direction to encompass overlay interface. one half of the original 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. To avoid confusion several instances of the term "cracks" or "cracking" were changed to the term "flaws" because of the use of alternative flaw mechanisms.

Modified to require that a base metal grading unit include at least 1 in. of the length of the overlaid weld, rather than 3 inches.

(a)(2) When base metal cracking penetrates Alternative: (a)(2) When base metal flaws into the overlay material, the base grading unit penetrate into the overlay material, the base shall include the overlay metal within 1 in. of metal grading unit shall not be used as part of the crack location. This portion of the overlay any overlay fabrication grading unit.

material shall not be used as part of any overlay grading unit.

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 38 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 (a)(3) When a base grading unit is designed to Alternative: (a)(3) Sufficient unflawed be unflawed, at least 1 in. of unflawed overlaid overlaid weld and base metal shall exist on all weld and base metal shall exist on either side sides of the grading unit to preclude interfering of the base grading unit. The segment of weld reflections from adjacent flaws.

length used in one base grading unit shall not Modified to require sufficient unflawed overlaid be used in another base grading unit. Base weld and base metal to exist on all sides of the grading units need not be uniformly spaced grading unit to preclude interfering reflections around the specimen. from adjacent flaws, rather than the 1 inch re uirement.

(b)(I) An overlay grading unit shall include the Alternative: (b)(I) An overlay fabrication overlay material and the base metal-to-overlay grading unit shall include the overlay material interface of at least 6 in 2 . The overlay grading and the base metal-to-overlay interface for a unit shall be rectangular, with minimum length of at least 1 in.

dimensions of 2 in. Modified to define an overlay fabrication grading unit as including the overlay material and the base meta/-to-overlay interface for a length of at least 1 in, rather than the 6 in 2 requirement (b)(2) An overlay grading unit designed to be Alternative: (b)(2) Overlay fabrication unflawed shall be surrounded by unflawed grading units designed to be unflawed shall be overlay material and unflawed base metal-to- separated by unflawed overlay material and overlay interface for at least 1 in. around its unflawed base metal-to-overlay interface for at entire perimeter. The specific area used in least 1 in. at both ends. Sufficient unflawed one overlay grading unit shall not be used in overlaid weld and base metal shall exist on another overlay grading unit. Overlay grading both sides of the overlay fabrication grading units need not be spaced uniformly about the unit to preclude interfering reflections from specimen adjacent flaws. The specific 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: Paragraph 1. 1(e)(2)(b)(2) states that overlay fabrication grading units designed to be unflawed shall be separated by unflawed overlay material and unflawed base meta/-to-overlay interface for at least 1 in. at both ends, rather than around its entire erimeter (b)(3) Detection sets shall be selected from Alternative: (b)(3) ... base metal grading Table VIII-S2-1. The minimum detection units, ten unflawed base metal grading units, sam Ie set is five flawed base radin units, five flawed overla fabrication radin units,

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 39 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 ten unflawed base grading units, five flawed and ten unflawed overlay fabrication grading overlay grading units, and ten unflawed units. For each type of grading unit, the set overlay grading units. For each type of shall contain at least twice as many unflawed grading unit, the set shall contain at least twice as flawed grading units. For initial procedure as many unflawed as flawed grading units. 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.

(f) Sizing Specimen (1) The minimum number of flaws shall be ten. Alternative: (1) The .... least 40% of the At least 30% of the flaws shall be overlay flaws shall be open to the inside surface.

fabrication flaws. At least 40% of the flaws Sizing sets shall contain a distribution of flaw shall be cracks open to the inside surface. 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 Alternative: (3) Base metal flaws used demonstrations shall be oriented circumferentially.

circumferentially.

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

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 40 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 GRAM:

Alternative to Requirements 2.0 CONDUCT OF PERFORMANCE DEMONSTRATION The specimen inside surface and identification Alternative: The specimen ..... prohibited.

shall be concealed from the candidate. All The overlay fabrication flaw test and the base examinations shall be completed prior to metal flaw test may be performed separately.

grading the results and presenting the results to the candidate. Divulgence of particular specimen results or candidate viewing of unmasked specimens after the performance demonstration is prohibited.

2.1 Detection Test Flawed and unflawed grading units shall be Alternative: Flawed (base metal or randomly mixed. Although the boundaries of overlay fabrication) each specimen.

specific grading units shall not be revealed to the candidate, the candidate shall be made aware of the type or types of grading units (base or overlay) that are present for each specimen.

2.2 Length Sizing Test (d) For flaws in base grading units, the Alternative: (d) For ... base metal grading ...

candidate shall estimate the length of that part base metal wall thickness.

of the flaw that is in the outer 25% of the base wall thickness.

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

candidate. For the remaining flaws, the (b) When the depth sizing test is conducted in regions of each specimen containing a flaw to conjunction with the detection test and the be sized shall be identified to the candidate. detected flaws do not satisfy the requirements The candidate shall determine the maximum of 1.1 (f), additional specimens shall be depth of the flaw in each region. provided to the candidate. The 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 re ion.

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 41 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 POI PROGRAM:

d Alter . e to qui nts (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 Alternative: Examination procedures are personnel are qualified for detection when the qualified for detection when:

results of the performance demonstration a. All flaws within the scope of the procedure satisfy the acceptance criteria of Table VIII-S2- are detected and the results of the 1 for both detection and false calls. The performance demonstration satisfy the criteria shall be satisfied separately by the acceptance criteria of Table VIII-S2-1 for false demonstration results for base grading units calls.

and for overlay grading units.

b. At least one successful personnel demonstration has been performed meeting the acceptance criteria defined in (c).

c. 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.

d. The criteria in (b) and (c) shall be satisfied separately by the demonstration results for base metal grading units and for overlay fabrication grading units.

Serial No. 07-0555 Alternative Request RR-89-61 Enclosure 2 to Attachment Page 42 of 42 Table 1 Alternatives to Appendix VIII, Supplement 11 SUP RAM:

REQUI Iternative to OVERL equirements 3.2 Sizing Acceptance Criteria (a) The RMS error of the flaw length Alternative: (a) The ... base metal flaws is ...

measurements, as compared to the true flaw position.

lengths, is less than or equal to 0.75 inch. The length of base metal cracking is measured at the 75% through-base-metal position.

(b) All extensions of base metal cracking into Alternative: (b) This requirement is omitted.

the overlay material by at least 0.1 in. are Basis: The requirement for reporting all reported as being intrusions into the overlay extensions of cracking into the overlay is material. 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.