DCL-07-038, ASME Section XI Inservice Inspection Program Relief Request REP-1 U2

ASME Section XI Inservice Inspection Program Relief Request REP-1 U2

ML070990060
Person / Time
Site:	Diablo Canyon
Issue date:	03/28/2007
From:	Becker J Pacific Gas & Electric Co
To:	Document Control Desk, NRC/NRR/ADRO
References
DCL-07-038
Download: ML070990060 (36)

Text

Pacific Gas and Electric Company' James R.Becker Diablo Canyon Power Plant Vice President P.0. Box 56 Diablo Canyon Operations and Avila Beach, CA93424 Station Director 805. 545. 3462 Marc 28,2007Fax: 805.545.4234 PG&E Letter DCL-07-038 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Docket No. 50-323, OL-DPR-82 Diablo Canyon Unit 2 ASME Section XI Inservice Inspection Program Relief Request REP-i U2

Dear Commissioners and Staff:

Pursuant to 10 CFR 50.55a(a)(3)(i), Pacific Gas and Electric Company (PG&E) hereby requests NRC approval for Inservice Inspection Program Relief Request REP-i U2.

This request for relief contains alternative requirements for the ASME Section XI Repair/Replacement Program for schedu *ledpreemptive full structural weld overlays (SWOLs) to mitigate the potential for primary water stress corrosion cracking of susceptible material at Diablo Canyon Power Plant (DCPP) Unit 2.

Currently, this work is planned to be performed during the DCPP Unit 2 Fourteenth Refueling Outage (2R14) currently scheduled to begin February 4, 2008.

The bases for the request for relief are provided in Enclosure 1. Code Case N-740-1, "Dissimilar Metal Weld Overlay for Repair of Class 1, 2, and 3 Items Section Xl, Division 1", February 2007 Draft, is included in Enclosure 2.

The Performance Demonstration Initiative (PDI) Program alternatives and their bases with respect to ASME Code Section XI, Appendix VIII, Supplement 11 requirements are included in Enclosure 3.

PG&E requests approval of this relief request no later than February 1, 2008, to support preparations for the SWOLs during 2R1 4.

This communication contains a new commitment to be implemented following NRC approval of this relief request. The commitment is contained in .

If you have any questions, please contact Mr. Stan Ketelsen at (805) 545-4720.

A member of the STARS (Strategic Teaming and Resource Sharing) 4-O4 Attiance Catlaway

• Comanche Peak . Diablo Canyon . Pato Verde . South Texas Project

• Wotf Creek

Document Control Desk PG&E Letter DCL-07-038 March 28, 2007 Page 2 Sincerely, Jiames '. Beck~err Vice President - Diablo Canyon Operations and Station Director whyl /42 79/A Enclosu res cc: Diablo Distribution cc/enc: Edgar Bailey, DHS Terry W. Jackson, Senior Resident Inspector Bruce S. Mallett, Region IV Alan B. Wang, NRR State of California, Pressure Vessel Unit A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Cattaway - Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project

• Wolf Creek

Enclosure 1 PG&E Letter DCL-07-038 Enclosure I INSERVICE INSPECTION (151) RELIEF REQUEST REP-I U2 In Accordance with 10 CFR 50.55a(a)(3)(i)

USE OF WELD OVERLAYS AS AN ALTERNATIVE REPAIR TECHNIQUE

--Alternative Provides Acceptable Level of Quality and Safety--

1. ASME Code Component Affected Code components associated with this request are high safety significant (HSS) Class 1 dissimilar metal welds (DMWs) with Alloy 82/1 82 weld metal in the pressurizer nozzle-to-pipe connection that are believed to be susceptible to primary water stress corrosion cracking (PWSCC). There are six welds that are scheduled to have preemptive full structural weld overlays (SWOLs) applied. In addition, the SWOLs will extend across the six adjacent stainless steel pipe-to-safe end similar metal welds. These welds are scheduled to have SWOLs applied during the upcoming Diablo Canyon Power Plant (DCPP) Unit 2 Fourteenth Refueling Outage (2R1 4).

1.1 Category and System Details:

Code Class: ASME Class 1 System Welds: Reactor Coolant System Examination Categories: B-F Note: Following weld overlay installation, the subject welds presently included in the DCPP Risk-informed Inservice Inspection Program will be inspected in accordance with the requirements of this relief request.

1.2 Component Descriptions:

The application of this alternative is to apply SWOLs on one potentially PWSCC-susceptible safe end-to-pressurizer surge nozzle DMW, three safe end-to-safety nozzle DMWs, one safe end-to-relief nozzle DMW, and one safe end-to-spray nozzle DMW.

The SWOLs will extend outward across the adjacent stainless steel pipe-to-safe end welds. The applicable weld identification is as follows:

a) Weld No. WIB-439SE Safe End -To-Surge Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-438 (Line Identifier 2-*-l16-14SPL) 1

Enclosure 1 PG&E Letter DCL-07-038 b) Weld No. WIB-369SE Safe End-to-8010OA Safety Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-369 (Line Identifier 2-S6-729-6) c) Weld No. WIB-423SE Safe End-to-8010OB Safety Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-423 (Line Identifier 2-S6-728-6) d) Weld No. WIB-359SE Safe End-to-8010OC Safety Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-359 (Line Identifier 2-S6-727-6) e) Weld No. WIB-380SE Safe End-to-Relief Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-380 (Line Identifier 2-S6-730-6) f) Weld No. WIB-3455E' Safe End-to-Spray Nozzle Weld and adjacent Pipe-to-Safe End Weld No. WIB-345 (Line Identifier 2-S6-1 5-4SPL) 1.3 Component Materials:

a) Nozzles are Low Alloy Steel SA-508 CL2 (P-No. 3 Group No. 3) b) Safe End-to-Nozzle Welds and Buttering are Alloy 82/182 (F-No. 43) c) Safe Ends are Wrought Stainless Steel SA-182 GR F316L (P-No. 8) d) Attached Pipe is Wrought Seamless Stainless Steel SA-376 Type 316 (P-No. 8) and Welds are Stainless Steel (A-No. 8)

2. Applicable Code Edition and Addenda

DCPP Unit 2 is currently in the third 10-year ISI interval. The ASME Boiler and Pressure Vessel Code (Code) of record for the current 10-year ISI interval is Section Xl, 2001 Edition, including Addenda through 2003 for the Repair/Replacement and ISI Program. ASME Code Section Xl, 2001 Edition, no Addenda, Appendix ViII, Supplement 11, (Reference 8.2) as implemented by the Performance Demonstration Initiative (PDI) Program, is used for ultrasonic examination qualification for SWOLs.

3. Applicable Code Requirement

The applicable Code requirement for which relief is requested is ASME Code Section XI, 2001 Edition, including Addenda through 2003 (Reference 8. 1), IWA-441 0 and IWA-461 1, and ASME Code Section Xl, 2001 Edition, no Addenda, Appendix ViII, Supplement 11. (Reference 8.2) 2

Enclosure 1 PG&E Letter DCL-07-038 IWA-441 0 states, in part, the following:

"Welding, brazing, defect removal,...and installation shall be performed in accordance with this Article."

IWA-461 1.1 (a) states, in part, the following:

"Defects shall be removed in accordance with IWA -4422. 1. A defect is considered removed when it has been reduced to an acceptable size."

IWA-461 1.2(a) states, in part, the following:

"After final processing, the affected surfaces, including surfaces of cavities prepared for welding, shall be examined by the magnetic particle or liquid penetrant method to ensure that the indication has been reduced to an acceptable size in accordance with IWB-3500."

Appendix VI II provides requirements for performance demonstration for ultrasonic examination systems. Supplement 11 provides qualification requirements for full structural overlaid wrought austenitic piping welds.

4. Reason for Request

DMWs, primarily consisting of Alloy 82/182 weld metal, are frequently used in pressurized water reactor (PWR) construction to connect stainless steel safe ends to vessel nozzles, which are constructed of carbon or low alloy ferritic steel. These welds have shown a potential for PWSCC degradation, especially in components subjected to high operating temperatures such as the pressurizer. See EPRI MRP-1 69 "Technical Basis for Preemptive Weld Overlays for Alloy 82/182 Butt Welds in PWRs," October 2005 (Reference 8.3).

For the upcoming 2R1 4 refueling outage, 6 DMWs located on the pressurizer are currently scheduled to have SWOLs applied.

Repair/replacement activities associated with SWOL repairs are required to address the materials, welding parameters, ALARA concerns, operational constraints, examination techniques and procedure requirements for repairs.

ASME Code Section Xl, 2001 Edition, including Addenda through 2003 (Reference 8. 1), IWA-441 0 and IWA-461 1, do not address all the needed requirements for this type of repair since potential existing defects will not be removed or reduced in size and weld overlay of potential existing flaws in DMWs will be performed. Also, comprehensive and generic NRC approved criteria are not currently available for application of SWOL 3

Enclosure 1 PG&E Letter DCL-07-038 repairs to DMWs constructed of Alloy 82/182 weld material for mitigation of potential PWSCC.

In addition, ASME Code Section XI, 2001 Edition, no Addenda, Appendix ViII, Supplement 11 (Reference 8.2), cannot be implemented as written for ultrasonic examination of a SWOL repair. Enclosure 3 includes a discussion of the PDI Program alternatives and their bases with respect to Appendix ViII Supplement 11 requirements.

The alternative described in Section 5.0 is proposed to permit the implementation of SWOLs at DCPP Unit 2, for the repair/replacement requirements of the ASME Code Section XI, 2001 Edition, including Addenda through 2003 (Reference 8.1), IWA-4410 and IWA-4611 and ASME Code Section Xl, 2001 Edition, no Addenda, Appendix ViIl Supplement 11. (Reference 8.2)

5. Proposed Alternative and Basis for Use The ASME Subcommittee XI has recently approved Section XI Code Case N-740-1, "Dissimilar Metal Weld Overlay for Repair of Class 1, 2, and 3 Items," February 2007 (Draft), which is included in Enclosure 2.

This draft Code Case is the result of the industry's experience with weld overlay repairs for flaws suspected or confirmed to be from PWSCC, and for the first time directly applies to the Alloy 52M weld material that is primarily being used for weld overlay repairs.

This request proposes the use of draft Code Case N-740-1 for implementing the 6 scheduled SWOLs for potentially PWSCC-susceptible safe end-to-nozzle welds of the pressurizer. These SWOLs will include the six adjacent stainless steel pipe-to-safe end welds. This request applies to each of the welds listed in Section 1.2, which are generically depicted in Figure 1. The proposed alternative is scheduled to be performed during the upcoming 2R14 refueling outage in February 2008.

The ultrasonic and surface examinations will be performed on the temper bead portion of the SWOLs no sooner than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after completion of the third temper bead layer, instead of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the weld has returned to ambient temperature, as currently specified in draft Code Case N-740-1 Paragraph 3(a)(2).

The ultrasonic examination of the completed SWOLs will be accomplished with personnel and procedures qualified in accordance with ASME Code Section XI, 2001 Edition, no Addenda, Appendix ViII, Supplement 11 (Reference 8.2), as implemented by the PDI program.

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Enclosure 1 PG&E Letter DCL-07-038 5.1 SWOL Design The SWOLs satisfy all the structural design requirements of the pipe, assuming no strength contributed by the original safe end-to-nozzle welds nor the pipe-to-safe end welds, as if the welds were removed. As shown in Figure 1, the SWOLs will completely cover the existing Alloy 82/182 weld and will extend onto the ferritic nozzle and austenitic stainless steel material on each end of the weld, including the adjacent pipe-to-safe end weld. The SWOLs extend around the entire circumference of the nozzle.

Alloy 52M and 52 filler metals are compatible with all the wrought base materials and the DMWs and similar metal welds that will be covered by the SWOL.

The SWOLs will be designed as full structural overlays (assumed worst case flaw) in accordance with ASME Section Xl Code Case N-740-1, February 2007 Draft (Enclosure 2). Note that the details surrounding the design analysis for the SWOLs are being developed to support the DCPP 2R1 4 refueling outage and our vendor has committed to supplying this analysis to PG&E. The design analyses for the preemptive structural weld overlays will be available at the plant for NRC review at the beginning of the DCPP 2R14 refueling outage.

5.2 Welding The welding will be performed in accordance with draft Code Case N-740-1, using a remote machine gas tungsten-arc welding (GTAW) process and using the ambient temperature temper bead method with ERNiCrFe-7A (Alloy 52M) weld metal. Manual GTAW, using ERNiCrFe-7 (Alloy 52) or Alloy 52M will be used if local repairs of weld defects are necessary or additional weld metal is required locally to form the final SWOL contour in locations at least 3/16 inch away from the low alloy steel nozzles.

5.3 Examination The ultrasonic and surface examinations will be performed on the temper bead portion of the SWOLs no sooner than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after completion of the third temper bead layer instead of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after the weld has returned to ambient temperature, as currently specified in draft Code Case N-740-1, Paragraph 3(a)(2).

The 48-hour delay provides time for delayed hydrogen cracking occurrence. Draft Code Case N-740-1, Appendix 1 requires the machine or automatic GTAW process to be used for temper bead welding thereby eliminating the use of welding processes requiring flux for arc shielding.

The machine GTAW temper bead process is inherently free of hydrogen.

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Enclosure 1 PG&E Letter DCL-07-038 The GTAW process relies on bare welding electrodes and bare wire filler metal with no flux to absorb moisture. An inert gas blanket provides shielding for the weld and surrounding metal, which protects the region during welding from the atmosphere and the moisture it may contain and typically produces porosity-free welds. In accordance with the weld procedure qualification, welding grade argon is used for the inert gas blanket. To further reduce the likelihood of any hydrogen effects, specific controls will be used to ensure the welding electrodes, filler metal and weld region are free of all sources of hydrogen.

In addition, the use of the machine GTAW temper bead process provides precise control of heat input, bead placement, bead size and contour.

The very precise control over these factors afforded by the machine GTAW process provides effective tempering of the nozzle ferritic steel heat affected zone resulting in achievement of lower hardness and tempered martensite. This further reduces susceptibility to hydrogen-induced cracking.

EPRI Report 1013558, "Temperbead Welding Applications, 48-Hour Hold Requirements for Ambient Temperature Temperbead Welding," Technical Update, December 2006 (Reference 8.4), provides justification for allowing the 48-hour hold time on P-No. 3 Group No. 3 ferritic steel base material to start after completion of the third temper bead layer instead of the currently specified hold time in the draft Code Case N-740-1. EPRI Report 1013558 addresses microstructural issues, hydrogen sources, tensile stress and temperature, and diffusivity and solubility of hydrogen in steels.

Furthermore, past industry experience with the use of the machine or automatic GTAW process has resulted in no detection of hydrogen-induced cracking after the 48-hour hold Non Destructive Examination or subsequent ISI.

There is currently an ASME Xl Subcommittee action to incorporate the revised NDE hold requirement into draft Code Case N-740-1. Code Case N-638-3, "Similar and Dissimilar Metal Welding Using Ambient Temperature Machine GTAW Temper Bead Technique Section XI, Division 1," has been revised with Main Committee and Board of Nuclear Codes and Standards approval to specify NDE 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after completion of the third temper bead layer.

All examinations will meet the requirements of the draft Code Case N-740-1, (Enclosure 2), excluding qualification of the ultrasonic examination for the completed SWOLs. The ultrasonic examination qualification will be in accordance with ASME Code Section XI, 2001 Edition, no Addenda, Appendix ViII, Supplement 11 (Reference 8.2), as 6

Enclosure 1 PG&E Letter DCL-07-038 implemented by the PIDI Program. See Enclosure 3 for a comparison of differences between Appendix VIII and the PIDI program.

The PIDI Program allows closer spacing of flaws provided they do not interfere with detection or discrimination. The specimens used today for qualification to the Tni-party (NRC/BWROG/EPRI) agreement have a flaw population density greater than allowed by current ASME Code requirements. These samples have been used successfully for all previous qualifications under the Tni-party agreement program. To facilitate their use and provide continuity from the Tni-party agreement program to Supplement 11, the PIDI Program has merged the Tni-party test specimens into their structural weld overlay program.

The current configuration of these DMWs does not permit an ASME Code Section Xl, Appendix VI II Supplement 10 ultrasonic examination to obtain greater than 90 percent coverage of the required examination volume.

Therefore, none of these welds will receive a preweld overlay ultrasonic examination.

5.4 Conclusion Similar NRC approved requests have been used to produce acceptable weld overlays when applied to dissimilar metal welds with Alloy 82/182 weld material at other facilities (see Section 6). The proposed alternative uses ASME Section Xl draft Code Case N-740-1, (Enclosure 2) that has been developed to cover the most recent operating experience and NRC-approved criteria that are associated with similar SWOL applications.

Therefore, PG&E considers that this draft Code Case, the modifications described herein, and the previously NRC-approved PIDI Program ultrasonic examination qualification alternative to ASME Section XI, 2001 Edition, no Addenda, Appendix VIII, Supplement 11, provide an acceptable level of quality and safety, consistent with provisions of 10 CFR 50.55a(a)(3)(i).

6. Precedents Similar relief requests have been submitted by other utilities to address the issues that are contained in this request. The following relief requests have been approved by the NRC:

6.1 AmerGen Energy Company, Three Mile Island Nuclear Station, Unit 1, on July 21, 2004, in 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 7

Enclosure 1 PG&E Letter DCL-07-038 Station, Unit 1 (TMI-1)," Docket No. 50-289, (TAC No. MCI 201 ),

dated July 21, 2004, (ADAMS Accession No. ML041670510).

6.2 Constellation Energy's Calvert Cliffs Nuclear Power Plant, Unit 2, on July 20, 2005, in NRC letter, "Safety Evaluation for Calvert Cliffs Nuclear Power Plant, Unit No. 2, Docket No. 550-31 8, Relief Request for Use Weld Overlay and Associated Alternative Inspection Techniques," (TAC Nos. MC6219 and MC6220), dated July 20, 2005, (ADAMS Accession No. ML05I 93031 6).

6.3 Millstone Unit 3, on January 20, 2006, in 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)," Docket No. 50-423, (TAC No. MC8609), dated January 20, 2006, (ADAMS Accession No. ML-05326001 2).

6.4 Indiana Michigan Power Company, Donald C. Cook Unit 1, on February 10, 2006, in NRC letter, "Safety Evaluation of Alternative Regarding Repair of Safe-End-To-Elbow Weld I -RC-9-01 F at the Donald C. Cook Nuclear Plant Unit 1," Docket No. 50-315, (TAC No. MC8807), dated February 10, 2006, (ADAMS Accession No. ML-060240355).

6.5 Indiana Michigan Power Company, Donald C. Cook Unit 2, on March 1, 2007, in NRC letter, "Safety Evaluation of Inservice Inspection Program Relief Request ISIR-20," Docket No. 50-31 6, (TAC No. MC9305), dated March 1, 2007, (ADAMS Accession No. ML-0704601 21).

7. Duration of Proposed Alternative The alternative requirements of this request will be applied for the duration of up to and including the last outage of the current third 10-year ISI interval, which includes inservice examination requirements of draft Code Case N-740-1 (Enclosure 2), for any applied weld overlays. The use of draft Code Case N-740-1 is requested until the NRC approves use of the Code Case in a future revision of Regulatory Guide (RG) 1.147. Future inservice examinations of weld overlays at DOPP Unit 2 beyond this inspection interval will be in accordance with Code Case N-740-1 and any additional requirements imposed by RGI.147.

8

Enclosure 1 PG&E Letter DCL-07-038 8.- References 8.1 ASME Code, Section Xl, 2001 Edition, including Addenda through 2003.

8.2 ASME Code, Section Xl, 2001 Edition, no Addenda, Appendix VIII, Supplement 11.

8.3 EPRI MRP-1 69 "Technical Basis for Preemptive Weld Overlays for Alloy 82/182 Butt Welds in PWRs," October 2005.

8.4 EPRI Report 1013558, "Temperbead Welding Applications, 48 Hour Hold Requirements for Ambient Temperature Temperbead Welding," Technical Update, December 2006.

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Enclosure 1 PG&E Letter DCL-07-038 SS Safe End (SA-lU2 P3164)

\SE/Noxie Vk~MW AM ROc/AIU2 Balance SV40Ltai SbAcrmnn ihcftf Figure 1 -TpclSWOL Colnfiguration 10

Enclosure 2 PG&E Letter DCL-07-038 Enclosure 2 Case N-740-1 Dissimilar Metal Weld Overlay for Repair of Class 1, 2, and 3 Items Section X11, Division I February 2007 Draft

MC6-165 1 2-1.9-07 editig and review Findl

ýCas~e N-740-1 Dissimilar Metal WeldOverlay for Repair of'Class 1,. 2. and, 3IteMs Section Xl, Division t Iquirqy*. As an alentv otepoiions of IWA-44110 and: IWA-46 11 for reducing a defect to an acceptable size in accordance: with.the. provisions: of thleýC~onstruct~ion:Code.

ecio X, s iTpermissible o reduice' a defc to a flwoacpbe sizeb or increasing thd wall thickniess, or to. apply, a:1mitigationa to a pecifried locationi,,by deposition of weld overlay. on: the outside surface of the pipngcomponentorass~ciated-w~eld?

Rel:It is the opno of the Comt 66ethai lieuo the reurmnsoW -44 1 and: IWA-461 1, a'defect in ausgtenitic stainless ,stieel. or austenitic nickel alloy pjirig,

components orassociated welds many,.be reduced to a 'flawof acceptatble. siz 'in accord~antce w6ith IWB-3,6410 by addition of a repair weld overlay. Alterniatively, f mitigation is performed,ý it may.also: be: developed*b treating a.postulated. flaw in accordanic e with IB-3 640 b~yapplicaio ofa mitigative wed oerla.AlStinX referenices are to the 2,004 Edition with the2006.Addenda.; Forithletuse-ofths Case withil other Editions and. Addenda rfer to:Table 1..The wed6overlay shallbeý appliddby depositbon of weld .re~inforcemenidt ,(weld overlay) onfthe~outside .surface. of the piping, component, or associated weld, includin ferrtcm teas we ncsayprovide~d the flowing requieet r e.

1Genera Reuirements

()Afull-stiuct'tal weld'overlay. shlbe appiied'by deposition of wel rifrcement (wyeld -ovely on the- outside sufc of,thelowalloysteel ozzls(-o ) otesf enid(P-N. 8 or 43,icuveoth N06082 or WV86 182wed, Atha on the tw temsi.

dsgn ofteoverlay may be extended to: include the adjacent stails te o Th stinless steel: Welds (M-No. t'to P-o. 8).ý (b): ThisCsi ppistodsimlrm wedldsbetweeP-No..8, or43 andP Po.1,'3, 2A12,o12maerkias Tis.Case al S;o apple to-dissimilIar metal welIds between:P No.8, ad -No.43 materials joine'dwith austeniitic F-No4 fIllrmtl n o d between~ Pý-No. 8 anid P-No. 8:materials as described in paragraph: I (A)1 a6e.

(c). Weld ,overlay.filler, metal shall b~e austenitic nikel alloy (28% Cr min..,

ERNiCrFe- or ER.Niprfe-7) app'lie'd 36.0 d'g ronthcircumference of the item, adsalbdepo'site~d using :a:WeldingPric-edure. Sp~ecification:(WPS) for grovewldngquaifed in acordanc'ewithithhe Co'nsfruction Code.a~nd Owner'so Requiremenfts' andý identified in the Repair/Replacement, Plan. As analternative to:

te post weld hepattreatmaent (PWvFHT) rqieents ofithe'-.Consftwtion Codean QWtiers: requirements' te ollowig provisions may be appid (1).For.P-No.l base materials thie.Co~nst*ruction:Cod~e PWHT exemputions fo cimmeeta bt ed nay'be applied to exempt h permitted~~~~~~~

weld overlay fromn PWHT wit :theh flowing clarificatins

()The nomin:al. weld'thi~c.kness. shall be def ind as-the maimu oiverlay thickness applied. over the ferritic base: materil

'P-is. 12A,. I2B an n 2Cdn$* eintos refer,to specificý: matkerilcasifiicatkios originally id'entified inSection III and subskequetly reclassified in a later Edition of SctdioniX~.

BC06-1651 2-19-07 -editing and review Final (b)ý The base material thickcne~ss shall be as defined-as thie maximumn thick-ness of the ferritic mnaterial .where the overlay is applied (2) Appni 1 ma eue o mint-tempertr temper bead welding.

Ad Prior to de~position .ofthle.weldovevrlay, the surace to ,be%Weld overlaid. shall be examine*d by-the-liqi pntiant mtho;d. Indictoslagrta 1/16 in. (1.5, nmm), shalilbe removed,. reduced. in size, or corrected in accordance with the following r..eq.,uirementse (1) One or more layers of weld m~etal shall be applied to seal unacceptable inications in the- are'a-to be repaired with-or. without excavation. The

,thickness of thecse layers. shall not be use in meeting wedrifocmn dpsig th.ickniess reqduiriements. Peenin the unacceptaible .indication prior.to

%weldinigis permi .tted.

(2jf repair. ofindications identified -in 1(d) isre~quird, h area ;where the weld :ov'er1*ylay isto be depo!*sited,. Inclding any lcal repair or initial weld oelay'layr shadllbe examinfed by the liquid ptenetrant mto.Teae hallcntain no indicati ons: g~reateri than' 1/16: in..(1 mmn) prior to.the A.p .plicatio.n of the structural layers of the weld overlay.

(e) Weld overlay deposits shall.meet the following requirementsc.

The auste~nitic nickel alloy- weld.overlay: sh ah consist of at least -two.Weld lAyers deposited from afiller mate~rial WitIhACr content of At leastAO28%. The first layer, of weld; metal: deposited may no beý credited. toadthe requre thikness.Alteratvlyk, frPWR applicationsa'diluted firs laye may be credited toward the required thickness, provided the .portion of-the layer over the austeniti'cb'ase ýmaterfiz.al, ut~enitic -filler-materia weld and the 'associated" dilutifon zone frma daetfriicbase matera cotainn.s at: least 24%, Cr And the Cr ceontent. of the .deposited Weld metal. i's determined by: chemical anlyi o teprodJuction weld oofarpentive cuotaefrm,a mockup prepared in: accordance:.w.ith the WPS for the production weld.,

Alternatively, for BWVR.aplctosadiuefislyrmyberdtd toward thereurd thickness prvdd the poto f the la-yer over thie:

austenitic base,material, austenitic filler materi al. weld and th asoiae dilution zonefroin an adjacent fernitic baseimaterial conrtainis at least20%-Cr*

and the Cr contenit of the ýdepositedýweld metal is, determined by chemical aaysis. ofte production w'eld or ofarpesnaie coupon. taken, from a mfocku~p prepared in' accordance with the WPS :for the production weld..

()This Cas onl fo edin in plicain prdictd not to have exceeded Is

'themnial nieutron ,fluence' of'l1x' 1017 (E<ý0.5,,eV.)neutrtons per..cmiprior to' welding.

()A new Weld overlay shall not b~e. installed over the16ý top .of.-an.existing weld overlay that has been. in.:service.

2

BC06-165 1 2- 19-07 editing. and Treview Final-2: Crack Growth and Deig (a): Crack Growth.

The sized of all flaws detected or postulated in the original weidment shall be.

projecitedto; the end of Ithe,expected .* life ofthe overly Crak owt du t both strss corros-ion a.nd fatigue 'shall be evaluated. Flaw characterization and

.evaluation shall be based on -the,ultrasonic examination results.

()For repair, overlays, the initial flaw-*siz~e for crack' grwh sall be based onl the as-found flaw.

(2): For mitigative overlays, the' iniilpostulated flaw-sizefor crack growth shallibe, assumed. consistent wit he examinations pe~rformed, either'pr .eor post overlay. The axial flaw leng~th shall be set at 1.5 inches (38 mm):or-the combined width of the -weld,pls buftteig whichever is'gretrTh circumferentia -flaw len'gth: shall be asued to,be 36 eg.

(a f'anie'xamination is perfonnedý 'or to applicationoofite:ov~erlay,.

which::is qualified in acco~rdac with Appendix' VIII, Supplement 11I

.and nho 'inside surfa-ce~p'conete plnr &lw 6rdiscovered, initial fawsý (originated from the. inside suirface of the weldment) equal to 10%lof the :origial wal thk`kness :shl tbe assumdinbthte xa and circumferential directions..

m(b) if no. examination is perform'ed prior, to application~of the overlay, initial flaws. eqatotles 75% trugh the origina wlthckness shal ble a'ssu,med, n bothi:fA the axfiaadocircumferential directions, conisistent with the -overlay.inservice inspe~ctiio~n vlume.,in Figz. 2.

()T~hderemay be circumstatnces inIwhich anooverla y .e.x.amination is performed using an ultrsonic examinatin ,proceduire.which is qulifiedminaccordance with Appendix VII Splemient 11 for -depths greater than the outer:25%/ ofd te or~iginal wall thckness: (Fig. 2). Forý sluch, cas~es, initial flaw size a be asmd' et the

&ossetwt to tehiceamnatonpro=cedue squalified..

(jAnyinsiide suiface: connected planar. flaw-found by ihe. overlay preservice inmspecition of prgah3'(b) wch exceedte detho (a),,(b): or (c) above, shall be used as the initial flaw depth in determining the 'expeýcted life.of theoverlay. Overlays etn this co .n~ditio.nshall be coinsideiredd a repair.,

() Sitru~ctural De sign andý Sizing 'of'the,Ovela

~ deino

'The~ h ~ edoelysalstsyteflowing;

~ ~ ~~~~j using he;

-a~ssumptions anidflaw charcteriztation: restri~ctions in ý2(a). The following, design analysis shal 'be completed naccordance wi~th IWA -431:1 3

8CO6- 1651.

2-19-07 editing and~review Final (1) The axial length and-end slope of the Weld overlay shall cover the: weld and. the heat affected zones on each side of the weld and: shall provide for load redistribution from the iteminifto the weld overl-ay and .back intothe item, without violating applicable stress limits of N13,3200, or the Construction.Code. Any laminar flaws in the weld overlay shall be evaluated in the analysis to ensuire that.load redistribution complies with the, above. 'These req~uireme-nts will11 usual ly be satisfied if the welld.overlay.

fuI thickness length extendsýaxiaýlly beyond the. poetd'flaw byat least 0.75-1itIwhere:R is the ,outer radius of the item and. tis the nominal

.wall thickness of the item.

(2) Unless specifically analyzed in acc~ordanc ithW2(b) (1), the end trantsitioin slpe.of the 'overlay shall not: exceed. 30 deg.- A slope of not more than 1::3 isý recommended-

.(3) For determining the cbine legtdf cWc6feetllly-oien ted flaw in the u~nderlying.,base material or weld,;multiple flaws shal be treated. as one, flaw of length equ4al;tote1uio"helngh.o'h individa faws chrctrzd in.6accordance' with IWA-3300-.

(4) For circumferentiallyorented flawsin the upnderl~ying bas* aeilo wlthe flaws shl be assumdto be 100% throuigh teborginalwall th~icknessoofh itemi for the entire-,circumnference. ofithe item..

(5). For jaxial. flaw ath underlying bas ma1iowlteflw hl be assumeiid'to b~e100% t~hrough the .origlinalwanlle tikess of the item forth entire: axal length of the flaw or com'bined flaws, aplcble 'I" for the

'entr circ umfeene.

()Formthi gative full structural overlays, te assumed flaw in, .heunderlyn

,base,material: orý wel d i~s to bebbased on the limiting case of the two below:

(4): 100%.Ithrough wall for the entire circumference, or (b)1600%Othrough. wall f.,or 1.5 in., (38 mhm) or the combinedwidth of the weldpl~us butterinwihvri greater in teaxial; dietonfoth

'entire circun~iference.:

(7) The ovyerlay design thickniess ýshall be' baisedi on the measuredý circumferece, using only the weld overla-y thickness ,conforming to the deposit ana lysis requi remjents of 1(e). Th cobnd"wlthcnss a h weld overlay, lany planar flaws ineedoverlayj, and h effects :of any:

.disconitinuities'(e.-g., ano~th er, weld.overlay-or reinforcemnent frabranch, conction) within a distanc Ieof rm h oso0..htheweld ovrly,including the flaw size assumptionsdefined In *()(4)j (5),. or(6) aboveý, shall be evaluat ed and shallet the: requi~rements of, IWB-3 64, IWC-;3 640' or IWD-3 6,40 as; applicable.

(8)The effects of any changeýs ,i~napp~lied lo-ads, as:.a resu#lt ,ofweld shriniikage froithe entire overlay oother items in the pipn syte 4(.g.sulpport loads and clearance .s$,nozzle loads, changes -in system. flexibility and weig .htdetoithe wed ovray), shI -beeqvaluated. Ekxistingflw 4

BCO6-16'51 2-19-07 editing: and review Final' previously accepted by analytical evaluation shall be evaluated in accordanc with IWB-3640,, IWC-3640, or JWD-3640.as applicale.

3 Examination.

In lieu of all other examination requirements, theý examination r~e~qureme~nts of thi Case.

shall be met . Nondestructive .examination methfods shall be-in accordanice With IWA-

.2200,.exceppt assspcified herein. NondestructiVe ekaminatio~n personnel shllbe.

qualified in' accordance with IWA-2,3 00.. Ultrasonic exami.nation procedu~re~anid personnel; shall be qualified "inaccortdan~e, With Appeni Vin,SSupplment 11.

(a)Acceptance Examination

,(I):T~he weld overlay shall have.: surface fiis of 250% miroin. ý(6.3

'micromtetes.).RMS orbetter. And A, flatness that is, sufficient to. allow folr adquate examination in accordance ,with: p~roreduires qu~alified per Appendix VIEI, The weld~overlay shal be examined to verify acceptable configuration.,

.(2)ý The wel~d overla~y and -the adjacenit base material ýfor, at least !/2 -in..(13s mm)

-from ecach side ,ofthe ,weldýshall b~e examined'using :the liquid .penetrant

,method. The.weld overla shall ýsatisfy the surfae examination acceptance, criteria for welds of the ýConstruction iCode or 7B5300. Th djcntbs metal. shall satisfy the sufc exmnto acepac criteria for bas material of the. Constrution Code or NB -2500. if abient temperature te~mper bead welding is. used,the:,' liquidpenetrant examination shall be c 'dutdat leas 48hor aft erthcompleted overlaylhas returned't ambident. tempeast ous (3). The. acceptance, examination volume, A-B-C-D, in'Fig. 1()sall be ultrasonically examined to -assure.adequate fu~sion.(.i*.e., adequate bond) wit, the base metal and to detect: weldin g 4aws,such assintterbead lack of fuision, inclusions,s.or cracks. The interface C-D. shown between teoverlay and the.

weld includes: the: bond and the heat. affected. zoerm the oIverlay if abettemperature. teme bead Weling-i used te ultrasonic examinationi shall be conducted'at least-48: hours, after the completed o vera has: returned to ambient temp~erature.,,

Plnrfaws detected in the wel overlay. acceptanceb eainationssAll,mee the preervice exanulnations§tandad of Tbe B-3514!-2 In applyingth e, acceptance, stanidajrds to. planar indications within th oume, EFG-,i Fig 1(),thethcknss t 1 shllbe used asthe nominalwall thcknss in

'Table.IWB-3542 Frparinctosoutsideti examination volume, the nomninal. wall thickness shall:be 't2 sshow min Figý.1(c),.for v'olumes A-Lamiin-arflas shall mieet the followimig (a) Laminar flaws shall. meet the acceptance: standards of Table IW.Bý-35-14.-3 wviththe additional limitation: that the toajaminar flaw shall not exceed 10Modflthie weldisufface area.an that no: linear dimension of the laminar 5

BC06-1651 2-19-'07 editing and review Final

'flaw area. exceeds 3.0 in. (76.mmn), or. 1.0% of the-nominal p~ipe circ~umnf erene whichever. is g,reater.,

(b) The reductionin coveragel of thie examination volume, A-BL-C-D.,in Fig.

1(a) due to laminar flaws shall ble' less than I0%. The uininspectable

.volume:is the volume in the weld overlay underneath 'the laminar flaws for, which ýcoverage .cannot be achiev~ed wýitha~ngle ~b~e am examination.

(c)An unnsectbl~ vlue i te wldoverlay%shall be assumed to contain the'.larges tradial planar-flaw.-that could: exist wit~hin that volume. This assumed flaw shall meet' the preser~vice "examination standards of Table IWB-3 51 4-2, with nominal wall thickness as defined above, for planar flaws. Alernately, th Ssuefa shall be04 eautdnd- mee the rquemnso W-ý3 64.,IC-60 or IWD-3640:as. applicable. ot axialand circumferential planar-flaws sall bet assumed.

%(4)After completion, of all welding, acivitis, affected rstrans suprs and snubbers shall betVT-3 visually, examined to verify that design tolerances are

,met.

(b).JPreservicc Inspectionz (1),iThe examinto voum in Fig. 2shallbe: ultasoicallyexamined. The ,angle

'beamshal .b~e di~reeted. perpen~dicul~a~r an6d paallto theppiingý,a.xis,.with scanning: pformed in four directions, to locatezand size ,any cracks thiat might have propagated int the upperý 25%, of the bas'e madterial or' into: the. weld oyerlay..

()Thepreservice~examinatiion,accepta.nce ,standards of Tbl IWB shalla be.met for th~e weld overl'ay. in applying the acpnestandards wall.

'thic.kness, U shall. be. te h:- thckn h ess of the weld overlay. COracks in the outer.

2%of theý base metal. shall meet, the design analysis§eqirements of 2(b)-.

()Tefaw evaluatOn rukes of IWAB-ý3 640, IWC-3640 or; l:IWD-ý3 640 shall not be applied to inldicationis .identied .during-preservice-exanminaion whic~h exceed

.the,presericep examination standards of Table IW.B-3S1:4-2.

(c)Iservice .In.spection

()Theweld overlay examination volume 'in Fig 2 'hall be added, to the inspecio pplan and ultrasonically examined during the first or second reuling. outagefo~llowing appl'ication.

(2)Aleratvely, fo~r mfitig-ative-weldoverlays inwiheaiationls are.

pdrformed in accordance,,with. 2(4)(2)(a), 3(a), and 3(b)an no inside srae

,connected planar flaw s are' di scover:ed,ý te ov'erlay ma epaced directly into ouation to be examined minaccordance with (c)(5 below th (3Mhewl overlay-examination volu4melin Fig..,2 s~hall be ultrasoically-

ýexamine to determine. if any. new o.r.ex.isting cracks' have propagated into the:

upper 25%I/ of the base materialo nto .the,overlay. The angle beam shall be directedperpendicula ad parallel tothe piping aiwthsann pefredin four directionis..

()Theýinservice examinatio iaccptnc stanidards of ThblIqW.B-35514-2 shall "bemef for the w.eld overlay., 'Ifthe adceptajitee criteria o~f Table LWB-ý35:14-2:

cannot: bemet, the acceptance criteria of IWB;-3 6P00, WC-3600, or IW~D-3 600 6

2-19-07.editing and review Final as applicable shall be met for the weld overlay Craks in the outer 25%/of the base metal shall meet the design-anialysis. requirements of Section 2 (b).

(5) Weld overlay examination volumsin Fig. 2 that show noidicaion of crack

.growýfo.th rew crackding~shall be placed into a population to be examined on a samlebass.Twenty-five percent of this population shall be exa~mined once

ýeveryl10years.

(6)Ifinsrvce xainations reveal crac or new cracking, whch me ffowt, the acceptancez crifteriIa-of.IVWB-'3*514, 1WB-3600, IWC_-3600,. or IWD-360.0 the weld 'overlayexam'inatio.n vol~ume shafllbe reexami~ned durin~gthe firsttor Second refueling outage..following discovery-of the growth or new' racking.

(7 or weld overlay, exmnAo oue itunacceptablemidcations according to 3(6)(4), the weld:,overlay'shall be removed,,including the original.

defective weld, and the, item saOllbe coq rrected by- a repair/replacemenit activity in accordac writh IA00

,(d) Additional Examiniations. If inservice examinations.: reveal an, unacceptable indication according to 3.(c)(4)), craick grwth into thewldorayesg thcnss, or -axial1crack growthi beyond ithe specified eaiton vlume additional weld overlay examination vol umes, eqal to: .0he nmerscheduledfor th.ecurre'nt fins~pection.period, .shall be exained prior to retr to service. If additional unacceptable indications are found in the second samnp le, a tota .f.'50%

o of the total population of weld overlay examintion volume~s'shall be exiamined prior to operation. If additional unacceptable indicationis are found,. the entire remaining population of weld. overlay eNamnihation volu m'es-.shall be examinhed prior to return to service..

4.0 Pressure 'Testing A systemleakage testshall be peforedin aodac with IWA- 000.

5.0O Documentation.

Use of this Case shall be do-ciumented on' Form;NIS-2.

7

BCO6-165 2-19-07 editing and review Final

.,07 c

a. Atccptance Exanilnutiovi Volume A-B3-CmO 112In.

(I ,Nple 1 4

x i*..

• 1

,w- G *i#

z

b. Thickness (ti),WotTmbab.WS-4614,-2 C.ThcIns (t) toTablei:WB.36144 Fig. 1IAcceptance Exaniiniation Volume anid Thic~kne~ss Deffinitions Notes:

'(!)'.For axial or circumt*ferenltial fl'aws,. the aixiall ektent of the .examtinationi volume sall extend at least./24xi(n(llnn)lbeyond the toes of the-originawed (2) :The weld includes: the' Ied ehd buitter, where -applied..

8

.BICO6-1 651 2-19-07 editing and review-Fina Exeamlnaticit~Voiwins A-B1-Cý-D

ý(1)ý For,,axial or circumIferenial flaws, the axia extn of th6eexaination volumehaill extend atleas~t 1/4 ,iný. (1i3mmý) b~ey.ond, the as-found flaw and at leat 12ini. (13mm beyondý the toe of teoiainl weld.

(2 The weld .ineludes~weld edp butr,Wk weeApplid Fig.12 Preservice and. inservice"E.xamrinationýVolume 9.

.BC06-1651 2- 19-07 editing and review Finial Mandatory Appen~dix I Ambien Tmeatuire.Temper Bead Welding I GENERAL REQUIREMENTS (a) This6 appendix applies to dissimilar a~usteniitic.filler metal welds between P-No. 1,3, 12A,, 1213, and' 1201 materials. and their associated welds.,and 'welds joining Pý-No. 8.or 43 materials to P-No. 1 3, 12A, 12b. and.120' materials With the following limitatio'n:

This Appendix shall not bez used to repair SA7302 Grade: B maiteriall unless the material has beenr: odified to include from 0.4% to611:0%, nickel, quenching and'te.mpering, and application of a fine grain practice.,

()The maxim~u m area.of an individual weld Overlay based on the finished surface over the ferritic base material shall be .500: so. in,(3125;0.00'sq.' mm).

()Repair/replacement acitivie' tn a'di'ssimilar-mfetal weld ,inaccord~ance~with' this Appe~ndix are limnited to those:6along-the fusion 'line' of a nIonrferritic weldto ferritic base matlenal on which: 1/8 in.(3 n~im), 'or le'ss of nonftrritic weld ~deposit exists above the original fusion.

line.

(d) Ifadefect pienetrates into the .feruthicbase material, repair of Ithe base material,. using a noriferrtic Weld filler material ýmaybei performed inaccordlance with. this,Appendb,,provided th§edethofrepair.intheý base material doesý not exce 3/8 in.(10mm).;

(e) Priorto welding the areai to be welded .and a band around the area'of at least1-112 times:

the .component thick'nessq ,r (130 ..mm), wIhichever isý less, shall .be,at east 5OF (10 C).

in.,0

()Welding materials shall.meet the Own~ers RqientadteCnsrction Cede and.

Cases specified inth'e Repaie/Replacemen P~lan. Welding materials shall be controlled so th-at they.are idenitified as::acPtablie:until consumed.,

(gPennga be usIe'd, :excep~ton theInlitial. and 'fina layers.

2. WELDIN *GQIJALIF-I'C-ATlNSý The welding, pro~cedures jand the weldyiing oprts sa~llbe qualified in-aicibcrance with Sectioný IX anid'the. requirements of 2.1 and 2.2.,

271 Procedure Qualification

(a) T~he base.materialsfor thieýw-el~din~g p'roced~ure qualification shall be of the same:P-Number and Group. Num ber, as thie materials, to be w.declded The: materials shall be:

p6te18ettrae to: at least the tim and temperature'ithat Was applied to the mapterials being weldd (b) The oo width ad inclded angle of theb'avit in the test assembly shall be no greater than the minimum specified foir the repair.

(M) The MaximIumnI interIpa.ss temperature for the first three: layers of the .fe~st~assePm~bly shall1 be'1 50F (660)ý.

(d)The .test.assembly cavity depth shaill. be at~least 1 in.(25 mm). The. test assemblyý ttkhicnesshall be at leastrtwice th e'test assembly cavity depth. The testaassemby

-shall be large' enough'to permit removal of the required test specimens., The.test, asIsem Ibly dimnensionýs surroundinig' thecavity shall be atleast thie ts ssml thickness and ~at least 6,in.(150 mhm). The qlualification test plate shall be lprepared in

.accordance with Fig. 1-'1.

()Ferritic base matra frte Iroedure qualificatin test shall meet the impact test requ.irements of the Con'structi~on Code anrd Ownears Requireme~nts..If .such requirements are not in the 'Consttrudton Code and O1wn.6es 'Re-quirem~ents, the impac3t,

.Properties shall be determined by Charpy V-notcht impact tests of the procedure qualification base: material at or: below the lowest service: temperature of the item .to be repaired. Thelocation and ~orient Iation of1t.he testI spec.imens s,8hall be s,iMilar to those required in 2.1(f):beloWi but shall: be inthe base mhetal..

10

BC06- 1651 2-1.9-07 editing and review Final (f) Charpy.V-notch tests of the ferritic heat-affected~zonie (HAZ)ý shall be performed at the same tem~perature as the base 'metal test of 2.1'(e)-above. Num ber, location,. and:

oIrienItation of. test spiecimens s§hall b.e asý foillows:'

(1), The. spec-imens shall be removed froma location as neoar as: practical to a depth. of..

of the deposited 'weldrmetal. The coupons for HAZ impact on :e- ,half. th.e thickne ssI specimensýshal be taken'tra,nsverse to theaxis of the weld an thdto define

-the,.HAZ. The notch of the Cbharpy:V-notch specime~n shall be cut appro~ximatel .y normal to. he material su'rface6 in such a.manne.ras to,include as much. HAZ as, possiblei in the resulting fractture.. When' the hmateriM~ 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)' I.ftthe teJst material is in.the formý,of a plate or aforgitig, the axis of the weld. shall be orie~nteod parallelt~o. the principal dhectioin of -11lingo forgng (f) The Charpy V-notch test shall :be perfor~m:ed in accordance wit SA:.370. Specimens shall be.:ini: accor`dance with SýA-37'0 Fig 11, Typ A. The test shall consist of a set of 'three~

1 m X10mmspcmens. The lateralN expansion,. percenit shear,:absorbed' energy, ful-iz teprature, oientato ad loc~tion of all testt specim'ens' s~hall be reported in the t estn Procedure Qualification Record.

(g) The average lateral expansion valueo~fthe three HAZ1Charpy V-fiotch specimens

- shall be.e~qual :to or greater thanthe average laterabl expansionvalue ofthe tre unafce bas mea specimens. However, if the'avteirage lIateralexaninvle of,the H~.AZ'Charpy V,-,notch,specimeh *sis le6ss than theV averaevaluel forthe.

unaffected base, Metal seimens and the procdure qlualificatdionmeets- all other requiirements of this-appendix, either of the foll.owing sh~all be peirformed:

(1) The4weldiing procedure shall. be reqUalifled.

()An Adjustment Temperatureý for, te procedure qaicato shl be.deemie

.inacco66rdance with the applicable provisions of NB-4335.2 of.Seition I,20 EIditi Ion.with 2002 Addenida.: The-RTNDT or. ldowet service temprat .ure.of the:

m.aterials'for'whlch the' welding procedure will be Used -shall bhicreased byea temnperalture eqIuivalent to. that of the AdOjustment Temperature,.

2.2 Performance Quali.fication W.el[ding operatorsý shal 1*be qualifi.eld in acco~rdanPe-with Section IX.

OJW1INO3PROCEDURE REQUIREMENTS The'weldiln~g procedure shall include'the followingý requirements:

()Teweld. metal shall be deposited by-the automatic or machine,.GTAW process.

(b) Dissimilar metal welds shall be made'usingA-No. 8 Weld metal (QW-442) for P-No'. 8'

to P- No. 1,3 or 12 (,B,.or:C) weldjo~ints or. FNo., 43ýweld metal (QW-432) for.P-ý No. 8 or 43: to. P-N~o. 1,3,.or 12 (A,B,or C)' weld joints..

(c) The.,area to be welded shall be buttere~d'wi'th-.a dleposit o~f a'tleast three l..ay'ers :to

achieve: at least 1/8 in.(3mmn), overlay th.ickness.wi..tIh the heat input for each [aIyer

ýcontrolled to within +/-10% of that used inthe %procedure.qualification test. The heat input of theý first three layers shall not exceed 45kJ/in (1.8 kJ/mm) under any conditions. Partiular care shall be taken inthe placement of the weld layers of the.

ovrly lle mteralat the toe of the overlay to-en~sure-that the HAZ and

'autenti ferritic base Metal are.tempered. Subsequent layers s~hall be depositediWitha:heat input not excleedling that used for layers beyond the third layri the poedur*e quaicaon

()The maximumn interpass temperature for field applicationfs-shall-be 350F (iSOC) for all Weld layers. regardless of the interpass temperatureused during qualification. The interpasst temperature limitation of QW-V4*06.3 .need not be applied.

()The interpass temperature. shallI be. det-ermined by:

.11

B.C06-1.651.

2-19-07 editing. and revie W Final

()Temperature measurement (egOyrometers,. temperature indicating crayons urig wldig. hen it is impractical'to'use interpass.

themocupls) temperature, measupremients. described in this paragraph due to situations where

'as; internal -bore Weld-Ing or when ther~e the weidmen ,t are .a is In .ot accessible,:such are, exte~nuating radiological concerns, either paragrap-h*3(p)(2):or paragraph 3(e)(3). may be used.

(2). Heat flowcalculati .ons.using.th~evariables listed belowýas a minimum:.

(i) weldinfg heat1 Iput.

(ii) initial base material temnpertture' (iii) conifiguration, thic~kness, and mass of the item being welded (iv) thermal conductivity and diffusivityofteaeiasbngwld (v), arc time per weld pass and delay time. between each pass (vi) ýarc time to: compolete the weld:

(3): Meaisuremento~fthemaxikmum inte~rpasstemprturbtie on ate~stcoupon that is equal to or less: than'the thickne ss of theiteAdm to be welded. -The.maximum heat.

iinputpof the,welding prode ure shaill.be 'used in theiw.elding .of..the test :coupon.

.(f). Particular care shall be given to ensure that thd wld' regio-n isfree-of all potential' sources of-hydrogen. The surfaces-to be weldled,: filler metal and'shielding gas shall be: suitably; ýcontrolle.d..

'12,

BCO6-1 651 2-19-w07'editing: and. review Finial GENERALNOTE:-'. Base meal Charpy ,impact specimens: are: not.:

shown.

Fig. 1 QUALIFICATION TEST PLATE 13

BCO,6-651 2-19ý-07 editmingand review Final 2001 Edition with.2003 1995 'Editioh with 1995 Editionj*wit 1989Edition with. .1986 Edition with Addenda through' 2004 1996 Addenda 1995 Addenda 1991 Addendla 1988 Addendai Edition w~ith: through 2001 throulgh,19.95 through 1989 Edition.

Zfl06Adden .da Edition with,2002ý Edgition, with 199,0 Addenda Addenda __________

IWA-40,00: IWA-4000. IWA-4000 'IWA-4000 IWA-4000, & IWA-

.Repair/Replacempent .700.0 Activities_________

IWA-43 11 Configuration IWA -43.11 IW.A -43.11 NA ýNA Changes TWA441 OWelding, IWA 4410 IWA 44 10 IWA 441'0 IWA 44,10.

Brazing. Metal Remnoval, and. Installation -

GitneraI. Requirements

,IWA'3300 Flaw IWA-3300 IWA-3300 1IWA-,3300. JWA-31.09, Characterization. _______

IWA-4611 Defect IWA-46141 IWA-4421 & IW-4170 (b) WA -4120 Rmoval _______ IWA-4424 _______

IWB-3514 Standards~for JW.B.3514 IWB-3514 IWB-3514. IWB-3514 Category, B-F._______

IB/D-3600: IWIC-/D -3600: IWBIc/D -360, `I.WBCD-30 IWB/C/D -3600'ý Analytcal Evaluation ,

A _______ ______

JWBCI-340IWB/C. 0-364or 'I" -360or 'LIWB/C -3640 o IWB/C -3640:

IEvaluio Procedures IBC35 W/ 35 W/ 35 Table 1 R~eference'for Altteraive Editions and: Addenda-of Se~ton XI

• Applicabiliy 1.986 Edfitio with 1988:Addenda through 2004 Ed ition wt200 Addenda htiig With the 1989 Ed&the. 1989Addenda

Enclosure 3 PG&E Letter DCL-07-038 Performance Demonstration Initiative (P01) Program Alternatives and their Bases with Respect to ASME Code Section Xl, Appendix ViII Supplement 11 Requirements Appendix ViII, Supplement 11 PDI Modification 1.0 SPECIMEN REQUIREMENTS ______________

1.1 General _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

(b) The specimen set shall consist Modification: (b) The specimen set shall of at least three specimens consist of at least three specimens having having different nominal pipe different nominal pipe diameters and diameters and overlay overlay thicknesses. They shall include thicknesses. They shall include the minimum and maximum nominal pipe the minimum and maximum diameters for which the examination nominal pipe diameters for procedure is applicable. Pipe diameters which the examination within a range of 0.9 to 1.5 times a nominal procedure is applicable. Pipe diameter shall be considered equivalent. If diameters within a range of 0.9 the procedure is applicable to pipe to 1.5 times a nominal diameter diameters of 24 inches or larger, the shall be considered equivalent. specimen set must include at least one If the procedure is applicable to specimen 24 inches or larger but need not pipe diameters of 24 inches or include the maximum diameter.

larger, the specimen set must include at least one specimen The specimen set shall include specimens 24 inches or larger but need not with overlays not thicker than 0.1 inches include the maximum diameter. more than the minimum thickness, nor The specimen set must include thinner than 0.25 inches of the maximum at least one specimen with nominal overlay thickness for which the overlay thickness within examination procedure is applicable.

-0.1 inches to +0.25 inches of the maximum nominal overlay Basis: To avoid confusion, the overlay thickness for which the thickness tolerance contained in the last procedure is applicable. sentence was reworded and the phrase itand the remainder shall be alternative flaws" was added to the next to last sentence in paragraph 1.1 (d) (1).

(d) Flaw Conditions (1) Base metal flaws. All flaws Modification: (1) Base metal flaws. All must be cracks in or near the flaws must be in or near the butt weld heat-butt weld heat-affected zone, affected zone, open to the inside surface, open to the inside surface, and and extending at least 75% through the extending at least 75% through base metal wall. Intentional overlay the base metal wall. Flaws may fabrication flaws shall not interfere with extend 100% through the base ultrasonic detection or characterization of metal and into the overlay the base metal flaws. Specimens material; in this case, intentional containing IGSCC shall be used when overlay fabrication flaws shall available. At least 70% of the flaws in the 1

Enclosure 3 PG&E Letter DCL-07-038 Appindix ViII, Supplement 11 PDI Modification not interfere with ultrasonic detection and sizing tests shall be cracks detection or characterization of and the remainder shall be alternative the cracking. Specimens flaws. Alternative flaw mechanisms, if containing IGSCC shall be used used, shall provide crack-like reflective when 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 PIDI 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 overlay thickness 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 2

Enclosure 3 PG&E Letter DCL-07-038 A~ppendix ViII, Supplement 11 PDI Modification with ultrasonic detection or characterization of the base metal flaws.

(e) Detection Specimens (1) At least 20% but less than Modification: (1) At least 20% but less 40% of the flaws shall be than 40% of the base metal flaws shall be oriented within +20 degrees of oriented within +/-20 degrees of the pipe the pipe axial direction. The axial direction. The remainder shall be remainder shall be oriented oriented circumnferentially. Flaws shall not circumferentially. Flaws shall be open to any surface to which the not be open to any surface to candidate has physical or visual access.

which the candidate has physical or visual access. The Basis: The requirement for axially rules of IWA-3300 shall be used oriented overlay fabrication flaws was to determine whether closely excluded from the PDI Program as an spaced flaws should be treated improbable scenario. Weld overlays are as single or multiple flaws. 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.

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

(a)(1) A base grading unit shall Modification: (a)(1) A base metal grading include at least 3 inches of the unit includes the overlay material and the length of the overlaid weld. The outer 25% of the original overlaid weld.

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

to-overlay interface. ___________________

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Enclosure 3 PG&E Letter DCL-07-038 Appendix VilI, Supplement 11 P01 Modification Basis: The phrase "and base metal on both sides," was inadvertently included in the description of a base metal grading unit. The PDI 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 inch of the length of the overlaid weld, rather than 3 inches.

i (a)(2) When base metal Modification: (a)(2) When base metal cracking penetrates into the flaws penetrate into the overlay material, overlay material, the base the base metal grading unit shall not be grading unit shall include the used as part of any overlay fabrication overlay metal within 1 inch of the grading unit.

crack location. This portion of the overlay material shall not be used as part of any overlay qradinq unit.

(a)(3) When a base grading unit Modification: (a)(3) Sufficient unflawed is designed to be unflawed, at overlaid weld and base metal shall exist on least 1 inch of unflawed overlaid all sides of the grading unit to preclude weld and base metal shall exist interfering reflections from adjacent flaws.

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

specimen.

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

square inches. The overlay grading unit shall be rectangular, Basis: Modified to require sufficient with minimum dimensions of unflawed overlaid weld and base metal to 2 inches. exist on all sides of the grading unit to preclude interfering reflections from 4

Enclosure 3 PG&E Letter DCL-07-038 Appendix Vill, Supplement 11 PDI Modification adjacent flaws, rather than the 2 inch requirement.

(b)(2) An overlay grading unit Modification: (b)(2) Overlay fabrication designed to be unflawed shall be grading units designed to be unflawed shall surrounded by unflawed overlay be separated by unflawed overlay material material and unflawed base and unflawed base metal1-to-overl ay metal1-to-ove rl ay interface for at interface for at least 1 inch at both ends.

least 1 inch around its entire Sufficient unflawed overlaid weld and base perimeter. The specific area metal shall exist on both sides of the used in one overlay grading unit overlay fabrication grading unit to preclude.

shall not be used in another interfering reflections from adjacent flaws.

overlay grading unit. Overlay The specific area used in one overlay grading units need not be fabrication grading unit shall not be used in spaced uniformly about the another overlay fabrication grading unit.

specimen. 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 metal-to-overlay interface for at least 1 inch at both ends,

__________________________rather than around its entire perimeter.

(b)(3) Detection sets shall be Modification: (b)(3) Detection sets shall selected from Table VI II-S2-1. be selected from Table VIII-S2-1. The The minimum detection sample minimum detection sample set is five set is five flawed base grading flawed base metal grading units, ten units, ten unflawed base grading unflawed base metal grading units, five units, five flawed overlay grading flawed overlay fabrication grading units, units, and ten unflawed overlay and ten unflawed overlay fabrication grading units. For each type of grading units. For each type of grading grading unit, the set shall unit, the set shall contain at least twice as contain at least twice as many many unflawed as flawed grading units.

unflawed as flawed grading For initial procedure qualification, detection units. 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.

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Enclosure 3 PG&E Letter DCL-07-038 Appendix ViII, Supplement 11 PDI Modification (f) Sizing Specimen (1) The minimum number of flaws Modification: (1) The minimum number of shall be ten. At least 30% of the flaws shall be ten. At least 30% of the flaws shall be overlay fabrication flaws shall be overlay fabrication flaws. At flaws. At least 40% of the flaws least 40% of the flaws shall be open to the shall be cracks open to the inside inside surface. Sizing sets shall contain a surface. 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 Modification: (3) Base metal flaws used length sizing demonstrations for length sizing demonstrations shall be shall be oriented oriented circumferentially.

circumferentially.

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

0.1 inch in the through-wall direction.

2.0 CONDUCT OF PERFORMANCE DEMONSTRATION The specimen inside surface and Modification: The specimen inside identification shall be concealed surface and identification shall be from the candidate. All concealed from the candidate. All examinations shall be completed examinations shall be completed prior to prior to grading the results and grading the results and presenting the presenting the results to the results to the candidate. Divulgence of candidate. Divulgence of particular particular specimen results or candidate specimen results or candidate viewing of unmasked specimens after the viewing of unmasked specimens performance demonstration is prohibited.

after the performance demonstration The overlay fabrication flaw test and the is prohibited. base metal flaw test may be performed

_________________________separately.

2.1 Detection Test__________________

Flawed and unflawed grading units Modification: Flawed and unflawed shall be randomly mixed. Although grading units shall be randomly mixed.

the boundaries of specific grading Although the boundaries of specific units shall not be revealed to the grading units shall not be revealed to the candidate, the candidate shall be candidate, the candidate shall be made made aware of the type or types of aware of the type or types of grading units 6

Enclosure 3 PG&E Letter DCL-07-038 Appendix VIIII, Supplement 11 PDI Modification grading units (base or overlay) that (base metal or overlay fabrication) that are are present for each specimen, present for each specimen.

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

2.3 Depth Sizing Test For the depth sizing test, 80% of the Modification:

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

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

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Enclosure 3 PG&E Letter DCL-07-038 Appendix ViII, Supplement 11 PDI Modification 3.0 ACCEPTANCE CRITERIA 3.1 Detection Acceptance Criteria Examination procedures, equipment, Modification: Examination procedures and personnel are qualified for are qualified for detection when:

detection when the results of the (a) All flaws within the scope of the performance demonstration satisfy procedure are detected and the results of the acceptance criteria of Table the performance demonstration satisfy the VIII-S2-1 for both detection and false acceptance criteria of Table VI II-S2-1 for calls. The criteria shall be satisfied false calls.

separately by the demonstration results for base grading units and for (b) At least one successful personnel overlay grading units. 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 VI II-S2-11 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.

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

75% through-base-metal position.

(b) All extensions of base metal Modification: This requirement is omitted.

cracking into the overlay material by at least 0.1 inch are reported Basis: The requirement for reporting all as being intrusions into the extensions of cracking into the overlay is overlay material, omitted from the PDI Program because it is redundant to the RMVS 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.

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Enclosure 4 PG&E Letter DCL-07-038 Enclosure 4 Commitment 1)PG&E will have the design analyses for the preemptive structural weld overlays at the plant for NRC review at the beginning of DCPP 2R1 4 refueling outage.