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{{#Wiki_filter:BRUCE H HAMILTON Vice President Energy, McGuire Nuclear Station Duke Energy Corporation MGOO VP / 12700 Hagers Ferry Road Huntersville, NC 28078 704-875-5333 704-875-4809 fax bhhamilton@duke-energy.
{{#Wiki_filter:BRUCE H HAMILTON Vice President Energy,                                                                 McGuire Nuclear Station Duke Energy Corporation MGOOVP / 12700 Hagers Ferry Road Huntersville, NC 28078 704-875-5333 704-875-4809 fax bhhamilton@duke-energy.com September 9, 2008 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001
com September 9, 2008 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001


==SUBJECT:==
==SUBJECT:==
Duke Energy Carolinas, LLC (Duke)McGuire Nuclear Station Unit 1 Docket Number 50-369 Relief Request 08-MN-003 Pursuant to 10 CFR 50.55a(a)(3)(i), Duke hereby submits Relief Request 08-MN-003 for the use of an alternative to the examination requirements of ASME Code, Section XI. This request supports the examination of reactor vessel hot leg nozzle to safe-end and safe-end to pipe welds performed from the inside surface during the upcoming McGuire Unit 1 fall 2008 refueling outage. The proposed alternative provides for an acceptable level of quality and safety, consistent with 10 CFR 50.55a(a)(3)(i).
Duke Energy Carolinas, LLC (Duke)
Attachment 1 contains this relief request. Duke requests approval of this relief request by October 9, 2008 to support the inspection of these welds.If you have any questions or require additional information, please contact P. T. Vu at (704) 875-4302.Sincerely, Bruce H. Hamilton Attachment 1 40C4_7 www. duke-energy.
McGuire Nuclear Station Unit 1 Docket Number 50-369 Relief Request 08-MN-003 Pursuant to 10 CFR 50.55a(a)(3)(i), Duke hereby submits Relief Request 08-MN-003 for the use of an alternative to the examination requirements of ASME Code, Section XI. This request supports the examination of reactor vessel hot leg nozzle to safe-end and safe-end to pipe welds performed from the inside surface during the upcoming McGuire Unit 1 fall 2008 refueling outage. The proposed alternative provides for an acceptable level of quality and safety, consistent with 10 CFR 50.55a(a)(3)(i).
corn U. S. Nuclear regulatory Commission September 9, 2008 Page 2 xc: L. A. Reyes, Region II Administrator U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center, 23 T85 61 Forsyth St., SW Atlanta, GA 30303-8931 J. F. Stang, Jr., Senior Project Manager U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 H 4A Rockville, MD 20852-2738 J. B. Brady NRC Senior Resident Inspector McGuire Nuclear Station Attachment 1 McGuire Unit 1 Relief Request for Alternate Depth Sizing Criteria 20440-12 (3/30/2006)
Attachment 1 contains this relief request. Duke requests approval of this relief request by October 9, 2008 to support the inspection of these welds.
ENGINEERING INFORMATION RECORD AR EVA Document Identifier 51 -9090152 -000 Title McGuire, Unit i Relief Request for Alternate Depth Sizing Criteria PREPARED BY: REVIEWED BY: Name M. G. Hacker Name M. W. Key Signature Date 8/29/08 Signature tel 8/29/08 Technical Manager Statement:
If you have any questions or require additional information, please contact P. T. Vu at (704) 875-4302.
Initials Reviewer is Independent.
Sincerely, Bruce H. Hamilton Attachment 1 40C4_7 www. duke-energy. corn
Remarks: This document contains a relief request drafted to address the use of an alternate depth, sizing criteria for sizing cracks, This document was prepared for Duke Energy and is applicable to the ultrasonic examination of the McGuire, Unit 1 hot leg RPV nozzle to safe-end and safe-end to pipe welds during the. September 2008 outage.AREVA NP Inc,, an AREVA and Siemens company Page I of 6 ALTERNATIVE DEPTH SIZING CRITERIA Duke Energy McGuire Unit 1 51-9090152-000 Page 2 of 6 ALTERNATIVE DEPTH SIZING CRITERIA Proposed Alternative In Accordance with 10 CFR 50.55a(a)(3)(i)-Alternative Provides Acceptable Level of Quality and Safety -Background Duke Energy is submitting a request for the use of an alternative to the examination requirements of ASME Code, Section Xl, at McGuire Nuclear Station (MNS) Unit 1.This request supports the examination of reactor vessel outlet nozzle to safe-end (dissimilar metal) and safe-end to pipe (similar metal) welds performed from the inside surface during the next scheduled outage. Duke Energy has determined the proposed alternative provides for an acceptable level of quality and safety; consistent with 10 CFR 50.55a(a)(3)(i).
 
1.0 Applicable Code Edition and Addenda MNS 1 is currently in the third 10-year ISI interval that began onl2/01/2001 and is scheduled to end on 11/30/2011.
U. S. Nuclear regulatory Commission September 9, 2008 Page 2 xc:
The ASME Boiler and Pressure Vessel Code (ASME Code) of record for the current period of the third 10-year ISI interval is the 1998 Edition of Section XI of the ASME Code, 2000 addendum.
L. A. Reyes, Region II Administrator U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center, 23 T85 61 Forsyth St., SW Atlanta, GA 30303-8931 J. F. Stang, Jr., Senior Project Manager U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 H 4A Rockville, MD 20852-2738 J. B. Brady NRC Senior Resident Inspector McGuire Nuclear Station
Section XI Code Case N-695 (Qualification Requirements for Dissimilar Metal Piping Welds)and Code Case N-696 (Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface) are referenced in the ISI program. These Code Cases are listed in Reg. Guide 1.147, Rev. 15, Table 1-"Acceptable Section XI Code Cases".2.0 Applicable Code Requirement ASME Section XI, Table IWB-2500-1, Category B-F, Item B5.10, Reactor Vessel Nozzle to Safe-end Butt Welds, specifies volumetric examination for the dissimilar metal welds. The safe-end to pipe welds are part of the Risk-Informed program and will also be volumetrically examined due to the close proximity to the dissimilar metal weld. The volumetric examinations are to be conducted in accordance with ASME Section XI, Appendix VIIl, Supplements 2 and 10, 1998 Edition with 2000 Addenda. Code Cases N-695 and N-696 are acceptable alternatives to Appendix VIII, Supplements 2 and 10.The specific Code Case requirements for which relief is requested pertains to the depth sizing qualification requirements for performance demonstration of ultrasonic examination systems for dissimilar and similar metal piping welds as listed below. These same requirements exist in ASME Section XI, 1995 Edition with 1996 Addenda and later editions.51-9090152-000 Page 3 of 6 0 3 PERFORMANCE DEMONSTRATION, o Code Case N-695 3.3 Depth-Sizing test: "(c) Examination procedures, equipment, and personnel are qualified for depth-sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in. (3 mm)." o Code Case N-696* 3.3 Depth-Sizing test: "(d) Supplement 2 or Supplement 3 examination procedures, equipment, and personnel are qualified for depth-sizing when the flaw depths estimated by ultrasonics, as compared to the true depths, do not exceed 0.125 in. (3 mm) RMS when they are combined with a successful Supplement 10 qualification.
 
3.0 Alternative Duke Energy proposes to use the Supplement 10 demonstrated value of 0.224.in. for dissimilar metal welds or the Supplement 2 demonstrated value of 0.222 in. for similar metal welds, as applicable, instead of the 0.125 in. value specified for depth sizing. In the event an indication is detected that requires depth sizing, the difference between the required RMSE and the demonstrated RMSE (0.099 in. or the 0.097 in., as applicable) will be added to the measured through-wall extent for comparison with applicable acceptance criteria.
Attachment 1 McGuire Unit 1 Relief Request for Alternate Depth Sizing Criteria
If the examination vendor demonstrates an improved depth sizing RMSE prior to the examination, the excess of that improved RMSE over the 0.125 in. RMSE requirement, if any, will be added to the measured value for comparison with applicable acceptance criteria.Consequently, Duke Energy proposes to use an alternative through-wall depth sizing criteria for similar and dissimilar metal welds that are examined from the inside surface. Examinations of these components will be performed during the next scheduled refueling outage at MNS 1 scheduled for September, 2008.4.0 Basis for Relief To date, although qualified for detection and length sizing on these welds, the examination vendors have not met the established root mean square error (RMSE) requirement for depth sizing (0.125 in.) when examining from the ID.Duke Energy's examination vendor has demonstrated ability to meet the depth sizing qualification requirement with an RMSE of 0.224 in. (dissimilar metal weld)and 0.222 in. (similar metal weld) instead of the required 0.125 in.. EPRI has published under their Policy/Procedure Directives the criteria of error in the RMS which has utility approval.Duke Energy has determined that the alternative in this request will result in an acceptable level of quality and safety, pursuant to the provisions of 10 CFR 50.55a(a)(3)(i).
 
The proposed alternative assures that the subject welds will be 51-9090152-000 Page 4 of 6 fully examined by procedures, personnel and equipment qualified by demonstration in all aspects except depth sizing. For depth sizing, the proposed addition of the difference between the qualified and demonstrated sizing tolerance to any flaw that is required to be sized compensates for the potential variation and likewise assures an acceptable level of quality and safety.5.0 ASME Code ComDonents Affected Category and System Details: Code Class: Class 1 System Welds: Reactor Coolant System Examination Categories:
20440-12 (3/30/2006)
Category B-F for dissimilar metal welds to reactor vessel nozzle Category R-A* for stainless steel safe end to pipe welds Code Item Numbers: B 5.10 for dissimilar metal welds to reactor vessel nozzle R 1.11* for stainless steel safe end to pipe welds*Welds are included in the Risk Informed Inservice Inspection Program I Hot leg safe-end to RV Nozzle-A Loop Nominal 21 with 2 5/8" wall 1RPV3-445E-SE 1NC1Fl-1 LAS nozzle/Alloy 82-182 weld/SS safe end/SS weld Nominal 29"I0 leg safe-end to i 2" 1 RPV3- LAS nozzle/Alloy-82-182 t egsae-ndtowith 2 5/8" ' 1NC1F2-1 Nozzle-B.
ENGINEERING INFORMATION RECORD AR EVA Document Identifier 51 - 9090152 - 000 Title   McGuire, Unit i Relief Request for Alternate Depth Sizing Criteria PREPARED BY:                                       REVIEWED BY:
Loop wall 445F-SE weld/SS safe end/SS weld t leg safe-end to Nominal 29"ID 1RPV3- NCF31 LAS nozzle/Alloy 82-182 Nozzle-C Loop with 2 5/8" 445G-SE weld/SS safe end/SS weld wall__ _ _ _ _ _ _ _ _ _ _ _Nominal 29"ID LAS nozzle/Alloy 82-182 t leg safe-end to 1 RPV3--" 1NC1F4-1LA ozeloy218 withI25/8" 4N5F4- weld/SS safe endiSS weld Nozzle-D Loop wall 445H-SE Component Materials:
Name   M. G. Hacker                               Name   M. W. Key Signature                         Date 8/29/08     Signature                         tel 8/29/08 Technical Manager Statement: Initials Reviewer is Independent.
: 1. LAS nozzles are SA-508 Class 2 Low Alloy Steel (P-3).2. SS safe ends are SA-182 Type 316 austenitic stainless steel (P-8).3. Welds are Alloy 82/182 (F-43).6.0 Duration of Proposed Alternative The proposed alternative to the ASME Code is applicable for the remainder of the third 10-year inservice inspection (ISI) interval at MNS 1.51-9090152-000 Page 5 of 6 7.0 Precedents A similar alternative request has been approved for use at the V.C. Summer Station in an NRC letter, dated February 3, 2004 (ADAMS Accession No.ML040340450) and for use at Diablo Canyon, Units 1 and 2 in an NRC letter dated October 26, 2005 (ADAMS Accession No. ML052660331) 8.0 References (1) 1998 Edition, ASME Code, Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2000 Addenda.(2) 1995 Edition, ASME Code, Section XI, with the 1996 Addenda, Appendix VIII, Supplements 2 and 10.(3) Code Case N-695, Qualification Requirements for Dissimilar Metal Piping Welds, Section XI, Division 1.(4) Code Case N-696, Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface, Section XI, Division 1.(5) EPRI Policy/Procedure Directives 51-9090152-000 Page 6 of 6}}
Remarks:
This document contains a relief request drafted to address the use of an alternate depth, sizing criteria for sizing cracks, This document was prepared for Duke Energy and is applicable to the ultrasonic examination of the McGuire, Unit 1 hot leg RPV nozzle to safe-end and safe-end to pipe welds during the. September 2008 outage.
AREVA NP Inc,, an AREVA and Siemens company                                             Page I of 6
 
ALTERNATIVE DEPTH SIZING CRITERIA Duke Energy McGuire Unit 1 51-9090152-000                                   Page 2 of 6
 
ALTERNATIVE DEPTH SIZING CRITERIA ProposedAlternative In Accordance with 10 CFR 50.55a(a)(3)(i)
              -Alternative ProvidesAcceptable Level of Quality and Safety -
 
===Background===
Duke Energy is submitting a request for the use of an alternative to the examination requirements of ASME Code, Section Xl, at McGuire Nuclear Station (MNS) Unit 1.
This request supports the examination of reactor vessel outlet nozzle to safe-end (dissimilar metal) and safe-end to pipe (similar metal) welds performed from the inside surface during the next scheduled outage. Duke Energy has determined the proposed alternative provides for an acceptable level of quality and safety; consistent with 10 CFR 50.55a(a)(3)(i).
1.0     Applicable Code Edition and Addenda MNS 1 is currently in the third 10-year ISI interval that began onl2/01/2001 and is scheduled to end on 11/30/2011. The ASME Boiler and Pressure Vessel Code (ASME Code) of record for the current period of the third 10-year ISI interval is the 1998 Edition of Section XI of the ASME Code, 2000 addendum. Section XI Code Case N-695 (Qualification Requirements for Dissimilar Metal Piping Welds) and Code Case N-696 (Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface) are referenced in the ISI program. These Code Cases are listed in Reg. Guide 1.147, Rev. 15, Table 1-
            "Acceptable Section XI Code Cases".
2.0     Applicable Code Requirement ASME Section XI, Table IWB-2500-1, Category B-F, Item B5.10, Reactor Vessel Nozzle to Safe-end Butt Welds, specifies volumetric examination for the dissimilar metal welds. The safe-end to pipe welds are part of the Risk-Informed program and will also be volumetrically examined due to the close proximity to the dissimilar metal weld. The volumetric examinations are to be conducted in accordance with ASME Section XI, Appendix VIIl, Supplements 2 and 10, 1998 Edition with 2000 Addenda. Code Cases N-695 and N-696 are acceptable alternatives to Appendix VIII, Supplements 2 and 10.
The specific Code Case requirements for which relief is requested pertains to the depth sizing qualification requirements for performance demonstration of ultrasonic examination systems for dissimilar and similar metal piping welds as listed below. These same requirements exist in ASME Section XI, 1995 Edition with 1996 Addenda and later editions.
51-9090152-000                                                                       Page 3 of 6
 
0   3 PERFORMANCE DEMONSTRATION, o   Code Case N-695 3.3 Depth-Sizing test:
                          "(c) Examination procedures, equipment, and personnel are qualified for depth-sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in. (3 mm)."
o   Code Case N-696
* 3.3 Depth-Sizing test:
                          "(d) Supplement 2 or Supplement 3 examination procedures, equipment, and personnel are qualified for depth-sizing when the flaw depths estimated by ultrasonics, as compared to the true depths, do not exceed 0.125 in. (3 mm) RMS when they are combined with a successful Supplement 10 qualification.
3.0   Alternative Duke Energy proposes to use the Supplement 10 demonstrated value of 0.224
        .in. for dissimilar metal welds or the Supplement 2 demonstrated value of 0.222 in. for similar metal welds, as applicable, instead of the 0.125 in. value specified for depth sizing. In the event an indication is detected that requires depth sizing, the difference between the required RMSE and the demonstrated RMSE (0.099 in. or the 0.097 in., as applicable) will be added to the measured through-wall extent for comparison with applicable acceptance criteria. If the examination vendor demonstrates an improved depth sizing RMSE prior to the examination, the excess of that improved RMSE over the 0.125 in. RMSE requirement, if any, will be added to the measured value for comparison with applicable acceptance criteria.
Consequently, Duke Energy proposes to use an alternative through-wall depth sizing criteria for similar and dissimilar metal welds that are examined from the inside surface. Examinations of these components will be performed during the next scheduled refueling outage at MNS 1 scheduled for September, 2008.
4.0   Basis for Relief To date, although qualified for detection and length sizing on these welds, the examination vendors have not met the established root mean square error (RMSE) requirement for depth sizing (0.125 in.) when examining from the ID.
Duke Energy's examination vendor has demonstrated ability to meet the depth sizing qualification requirement with an RMSE of 0.224 in. (dissimilar metal weld) and 0.222 in. (similar metal weld) instead of the required 0.125 in.. EPRI has published under their Policy/Procedure Directives the criteria of error in the RMS which has utility approval.
Duke Energy has determined that the alternative in this request will result in an acceptable level of quality and safety, pursuant to the provisions of 10 CFR 50.55a(a)(3)(i). The proposed alternative assures that the subject welds will be 51-9090152-000                                                                     Page 4 of 6
 
fully examined by procedures, personnel and equipment qualified by demonstration in all aspects except depth sizing. For depth sizing, the proposed addition of the difference between the qualified and demonstrated sizing tolerance to any flaw that is required to be sized compensates for the potential variation and likewise assures an acceptable level of quality and safety.
5.0 ASME Code ComDonents Affected Category and System Details:
Code Class: Class 1 System Welds: Reactor Coolant System Examination Categories:
Category B-F for dissimilar metal welds to reactor vessel nozzle Category R-A* for stainless steel safe end to pipe welds Code Item Numbers:
B 5.10 for dissimilar metal welds to reactor vessel nozzle R 1.11* for stainless steel safe end to pipe welds
                  *Welds are included in the Risk Informed Inservice Inspection Program I         Hot leg safe-end to Nominal 21       1RPV3-                LAS nozzle/Alloy 82-182 with 2 5/8"                 1NC1Fl-1 RV Nozzle-A Loop                      445E-SE               weld/SS safe end/SS weld wall leg tsafe-end Nominal egsae-ndtowith to 29"I0 i 2 5/8" 2" ' 1RPV3-        1NC1F2-1   LAS nozzle/Alloy-82-182 Nozzle-B. Loop wall              445F-SE               weld/SS safe end/SS weld t leg safe-end to Nominal 29"ID 1RPV3-         NCF31     LAS nozzle/Alloy 82-182 Nozzle-C Loop with 2 5/8"         445G-SE               weld/SS safe end/SS weld wall__                                     _  _ _   _ _ _ _ _ _ _ _
t leg safe-end to Nominal withI25/8"29"ID 4N5F4-1RPV3--"   1NC1F4-1LA LAS  ozeloy218 nozzle/Alloy weld/SS           82-182 safe endiSS   weld Nozzle-D Loop wall               445H-SE Component Materials:
: 1. LAS nozzles are SA-508 Class 2 Low Alloy Steel (P-3).
: 2. SS safe ends are SA-182 Type 316 austenitic stainless steel (P-8).
: 3. Welds are Alloy 82/182 (F-43).
6.0   Duration of Proposed Alternative The proposed alternative to the ASME Code is applicable for the remainder of the third 10-year inservice inspection (ISI) interval at MNS 1.
51-9090152-000                                                                         Page 5 of 6
 
7.0   Precedents A similar alternative request has been approved for use at the V.C. Summer Station in an NRC letter, dated February 3, 2004 (ADAMS Accession No.
ML040340450) and for use at Diablo Canyon, Units 1 and 2 in an NRC letter dated October 26, 2005 (ADAMS Accession No. ML052660331) 8.0   References (1)   1998 Edition, ASME Code, Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2000 Addenda.
(2)     1995 Edition, ASME Code, Section XI, with the 1996 Addenda, Appendix VIII, Supplements 2 and 10.
(3)   Code Case N-695, Qualification Requirements for Dissimilar Metal Piping Welds, Section XI, Division 1.
(4)   Code Case N-696, Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface, Section XI, Division 1.
(5)   EPRI Policy/Procedure Directives 51-9090152-000                                                                 Page 6 of 6}}

Revision as of 13:54, 14 November 2019

Relief Request 08-MN-003 for Alternate Depth Sizing Criteria
ML082600580
Person / Time
Site: McGuire Duke Energy icon.png
Issue date: 09/09/2008
From: Brandi Hamilton
Duke Energy Carolinas, Duke Energy Corp
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
08-MN-003
Download: ML082600580 (9)
v • d • e


Text

BRUCE H HAMILTON Vice President Energy, McGuire Nuclear Station Duke Energy Corporation MGOOVP / 12700 Hagers Ferry Road Huntersville, NC 28078 704-875-5333 704-875-4809 fax bhhamilton@duke-energy.com September 9, 2008 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Duke Energy Carolinas, LLC (Duke)

McGuire Nuclear Station Unit 1 Docket Number 50-369 Relief Request 08-MN-003 Pursuant to 10 CFR 50.55a(a)(3)(i), Duke hereby submits Relief Request 08-MN-003 for the use of an alternative to the examination requirements of ASME Code,Section XI. This request supports the examination of reactor vessel hot leg nozzle to safe-end and safe-end to pipe welds performed from the inside surface during the upcoming McGuire Unit 1 fall 2008 refueling outage. The proposed alternative provides for an acceptable level of quality and safety, consistent with 10 CFR 50.55a(a)(3)(i).

Attachment 1 contains this relief request. Duke requests approval of this relief request by October 9, 2008 to support the inspection of these welds.

If you have any questions or require additional information, please contact P. T. Vu at (704) 875-4302.

Sincerely, Bruce H. Hamilton Attachment 1 40C4_7 www. duke-energy. corn

U. S. Nuclear regulatory Commission September 9, 2008 Page 2 xc:

L. A. Reyes, Region II Administrator U.S. Nuclear Regulatory Commission Sam Nunn Atlanta Federal Center, 23 T85 61 Forsyth St., SW Atlanta, GA 30303-8931 J. F. Stang, Jr., Senior Project Manager U. S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop 0-8 H 4A Rockville, MD 20852-2738 J. B. Brady NRC Senior Resident Inspector McGuire Nuclear Station

Attachment 1 McGuire Unit 1 Relief Request for Alternate Depth Sizing Criteria

20440-12 (3/30/2006)

ENGINEERING INFORMATION RECORD AR EVA Document Identifier 51 - 9090152 - 000 Title McGuire, Unit i Relief Request for Alternate Depth Sizing Criteria PREPARED BY: REVIEWED BY:

Name M. G. Hacker Name M. W. Key Signature Date 8/29/08 Signature tel 8/29/08 Technical Manager Statement: Initials Reviewer is Independent.

Remarks:

This document contains a relief request drafted to address the use of an alternate depth, sizing criteria for sizing cracks, This document was prepared for Duke Energy and is applicable to the ultrasonic examination of the McGuire, Unit 1 hot leg RPV nozzle to safe-end and safe-end to pipe welds during the. September 2008 outage.

AREVA NP Inc,, an AREVA and Siemens company Page I of 6

ALTERNATIVE DEPTH SIZING CRITERIA Duke Energy McGuire Unit 1 51-9090152-000 Page 2 of 6

ALTERNATIVE DEPTH SIZING CRITERIA ProposedAlternative In Accordance with 10 CFR 50.55a(a)(3)(i)

-Alternative ProvidesAcceptable Level of Quality and Safety -

Background

Duke Energy is submitting a request for the use of an alternative to the examination requirements of ASME Code, Section Xl, at McGuire Nuclear Station (MNS) Unit 1.

This request supports the examination of reactor vessel outlet nozzle to safe-end (dissimilar metal) and safe-end to pipe (similar metal) welds performed from the inside surface during the next scheduled outage. Duke Energy has determined the proposed alternative provides for an acceptable level of quality and safety; consistent with 10 CFR 50.55a(a)(3)(i).

1.0 Applicable Code Edition and Addenda MNS 1 is currently in the third 10-year ISI interval that began onl2/01/2001 and is scheduled to end on 11/30/2011. The ASME Boiler and Pressure Vessel Code (ASME Code) of record for the current period of the third 10-year ISI interval is the 1998 Edition of Section XI of the ASME Code, 2000 addendum.Section XI Code Case N-695 (Qualification Requirements for Dissimilar Metal Piping Welds) and Code Case N-696 (Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface) are referenced in the ISI program. These Code Cases are listed in Reg. Guide 1.147, Rev. 15, Table 1-

"Acceptable Section XI Code Cases".

2.0 Applicable Code Requirement ASME Section XI, Table IWB-2500-1, Category B-F, Item B5.10, Reactor Vessel Nozzle to Safe-end Butt Welds, specifies volumetric examination for the dissimilar metal welds. The safe-end to pipe welds are part of the Risk-Informed program and will also be volumetrically examined due to the close proximity to the dissimilar metal weld. The volumetric examinations are to be conducted in accordance with ASME Section XI, Appendix VIIl, Supplements 2 and 10, 1998 Edition with 2000 Addenda. Code Cases N-695 and N-696 are acceptable alternatives to Appendix VIII, Supplements 2 and 10.

The specific Code Case requirements for which relief is requested pertains to the depth sizing qualification requirements for performance demonstration of ultrasonic examination systems for dissimilar and similar metal piping welds as listed below. These same requirements exist in ASME Section XI, 1995 Edition with 1996 Addenda and later editions.

51-9090152-000 Page 3 of 6

0 3 PERFORMANCE DEMONSTRATION, o Code Case N-695 3.3 Depth-Sizing test:

"(c) Examination procedures, equipment, and personnel are qualified for depth-sizing when the RMS error of the flaw depth measurements, as compared to the true flaw depths, do not exceed 0.125 in. (3 mm)."

o Code Case N-696

  • 3.3 Depth-Sizing test:

"(d) Supplement 2 or Supplement 3 examination procedures, equipment, and personnel are qualified for depth-sizing when the flaw depths estimated by ultrasonics, as compared to the true depths, do not exceed 0.125 in. (3 mm) RMS when they are combined with a successful Supplement 10 qualification.

3.0 Alternative Duke Energy proposes to use the Supplement 10 demonstrated value of 0.224

.in. for dissimilar metal welds or the Supplement 2 demonstrated value of 0.222 in. for similar metal welds, as applicable, instead of the 0.125 in. value specified for depth sizing. In the event an indication is detected that requires depth sizing, the difference between the required RMSE and the demonstrated RMSE (0.099 in. or the 0.097 in., as applicable) will be added to the measured through-wall extent for comparison with applicable acceptance criteria. If the examination vendor demonstrates an improved depth sizing RMSE prior to the examination, the excess of that improved RMSE over the 0.125 in. RMSE requirement, if any, will be added to the measured value for comparison with applicable acceptance criteria.

Consequently, Duke Energy proposes to use an alternative through-wall depth sizing criteria for similar and dissimilar metal welds that are examined from the inside surface. Examinations of these components will be performed during the next scheduled refueling outage at MNS 1 scheduled for September, 2008.

4.0 Basis for Relief To date, although qualified for detection and length sizing on these welds, the examination vendors have not met the established root mean square error (RMSE) requirement for depth sizing (0.125 in.) when examining from the ID.

Duke Energy's examination vendor has demonstrated ability to meet the depth sizing qualification requirement with an RMSE of 0.224 in. (dissimilar metal weld) and 0.222 in. (similar metal weld) instead of the required 0.125 in.. EPRI has published under their Policy/Procedure Directives the criteria of error in the RMS which has utility approval.

Duke Energy has determined that the alternative in this request will result in an acceptable level of quality and safety, pursuant to the provisions of 10 CFR 50.55a(a)(3)(i). The proposed alternative assures that the subject welds will be 51-9090152-000 Page 4 of 6

fully examined by procedures, personnel and equipment qualified by demonstration in all aspects except depth sizing. For depth sizing, the proposed addition of the difference between the qualified and demonstrated sizing tolerance to any flaw that is required to be sized compensates for the potential variation and likewise assures an acceptable level of quality and safety.

5.0 ASME Code ComDonents Affected Category and System Details:

Code Class: Class 1 System Welds: Reactor Coolant System Examination Categories:

Category B-F for dissimilar metal welds to reactor vessel nozzle Category R-A* for stainless steel safe end to pipe welds Code Item Numbers:

B 5.10 for dissimilar metal welds to reactor vessel nozzle R 1.11* for stainless steel safe end to pipe welds

  • Welds are included in the Risk Informed Inservice Inspection Program I Hot leg safe-end to Nominal 21 1RPV3- LAS nozzle/Alloy 82-182 with 2 5/8" 1NC1Fl-1 RV Nozzle-A Loop 445E-SE weld/SS safe end/SS weld wall leg tsafe-end Nominal egsae-ndtowith to 29"I0 i 2 5/8" 2" ' 1RPV3- 1NC1F2-1 LAS nozzle/Alloy-82-182 Nozzle-B. Loop wall 445F-SE weld/SS safe end/SS weld t leg safe-end to Nominal 29"ID 1RPV3- NCF31 LAS nozzle/Alloy 82-182 Nozzle-C Loop with 2 5/8" 445G-SE weld/SS safe end/SS weld wall__ _ _ _ _ _ _ _ _ _ _ _

t leg safe-end to Nominal withI25/8"29"ID 4N5F4-1RPV3--" 1NC1F4-1LA LAS ozeloy218 nozzle/Alloy weld/SS82-182 safe endiSS weld Nozzle-D Loop wall 445H-SE Component Materials:

1. LAS nozzles are SA-508 Class 2 Low Alloy Steel (P-3).
2. SS safe ends are SA-182 Type 316 austenitic stainless steel (P-8).
3. Welds are Alloy 82/182 (F-43).

6.0 Duration of Proposed Alternative The proposed alternative to the ASME Code is applicable for the remainder of the third 10-year inservice inspection (ISI) interval at MNS 1.

51-9090152-000 Page 5 of 6

7.0 Precedents A similar alternative request has been approved for use at the V.C. Summer Station in an NRC letter, dated February 3, 2004 (ADAMS Accession No.

ML040340450) and for use at Diablo Canyon, Units 1 and 2 in an NRC letter dated October 26, 2005 (ADAMS Accession No. ML052660331) 8.0 References (1) 1998 Edition, ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components," 2000 Addenda.

(2) 1995 Edition, ASME Code,Section XI, with the 1996 Addenda, Appendix VIII, Supplements 2 and 10.

(3) Code Case N-695, Qualification Requirements for Dissimilar Metal Piping Welds,Section XI, Division 1.

(4) Code Case N-696, Qualification Requirements for Appendix VIII Piping Examinations Conducted From the Inside Surface,Section XI, Division 1.

(5) EPRI Policy/Procedure Directives 51-9090152-000 Page 6 of 6

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