RS-16-041, Proposed Alternative to Utilize Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1

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Proposed Alternative to Utilize Code Case N-513-4, Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1
ML16029A003
Person / Time
Site: Calvert Cliffs, Dresden, Peach Bottom, Nine Mile Point, Oyster Creek, Byron, Braidwood, Limerick, Ginna, Clinton, Quad Cities, LaSalle, Crane
Issue date: 01/28/2016
From: David Gudger
Exelon Generation Co
To:
Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML17157A156 List:
References
RS-16-041
Download: ML16029A003 (8)
v • d • e


Text

201., Exelon W-y Exelon Generation Kennet' Square. PA 19348 www.exe1oni Drp.com 10 CFR 50.55a RS-16-041 January 28, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455 Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-53 and DPR-69 NRC Docket Nos. 50-317 and 50-318 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374 Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353 Nine Mile Point Nuclear Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-63 and NPF-69 NRC Docket Nos. 50-220 and 50-41 O Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219

U.S. Nuclear Regulatory Commission Proposed Alternative to Utilize Code Case N-513-4 January 28, 2016 Page 2

Subject:

Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265 R.E. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 NRC Docket No. 50-244 Three Mile Island Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-50 NRC Docket No. 50-289 Proposed Alternative to Utilize Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1 "

In accordance with 10 CFR 50.55a(z)(2), Exelon Generation Company, LLC (Exelon) is requesting a proposed alternative to the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," on the basis that compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Specifically, Exelon is requesting to apply the evaluation methods of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," to Class 2 and 3 moderate energy piping including elbows, bent pipe, reducers, expanders, and branch tees.

Peach Bottom Atomic Power Station and Quad Cities Nuclear Power Station have an approved relief request (ADAMS Accession Number ML15043A496) to utilize Code Case N-513-3 at a higher operating pressure than allowed by the Code Case. This relief request to utilize Code Case N-513-4 does not supersede or negate the need for the previous approval contained in ML15043A496. This relief request to utilize Code Case N-513-4 will only be applied to systems/components that meet the applicability conditions in Code Case N-513-4.

There are no commitments contained in this submittal.

U.S. Nuclear Regulatory Commission Proposed Alternative to Utilize Code Case N-513-4 January 28, 2016 Page 3 We request your review and approval of this multi-site request by January 28, 2017.

Respectfully,

~c- )1.'.,j_.)r--

David T. Gudger Manager - Licensing and Regulatory Affairs Exelon Generation Company, LLC Attachments: 1) Proposed Alternative to Utilize Code Case N-513-4

2) Marked-up Version of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1"
3) ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1"
4) Technical Basis for Proposed Fourth Revision to ASME Code Case N-513 cc:

Regional Administrator - NRC Region I Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Braidwood Station NRC Senior Resident Inspector - Byron Station NRC Senior Resident Inspector - Clinton Power Station NRC Senior Resident Inspector - Dresden Nuclear Power Station NRC Senior Resident Inspector - LaSalle County Station NRC Senior Resident Inspector - Limerick Generating Station NRC Senior Resident Inspector - Oyster Creek Nuclear Generating Station NRC Senior Resident Inspector - Peach Bottom Atomic Power Station NRC Senior Resident Inspector - Quad Cities Nuclear Power Station NRC Senior Resident Inspector - Three Mile Island Nuclear Station, Unit 1 NRC Senior Resident Inspector - Calvert Cliffs Nuclear Power Plant NRC Senior Resident Inspector - Nine Mile Point Nuclear Station NRC Senior Resident Inspector - R.E. Ginna Nuclear Power Plant NRC Project Manager - Braidwood Station NRC Project Manager - Byron Station NRC Project Manager - Clinton Power Station NRC Project Manager - Dresden Nuclear Power Station NRC Project Manager - LaSalle County Station NRC Project Manager - Limerick Generating Station NRC Project Manager - Oyster Creek Nuclear Generating Station NRC Project Manager - Peach Bottom Atomic Power Station NRC Project Manager - Quad Cities Nuclear Power Station NRC Project Manager - Three Mile Island Nuclear Station, Unit 1 NRC Project Manager - Calvert Cliffs Nuclear Power Plant NRC Project Manager - Nine Mile Point Nuclear Station NRC Project Manager - R.E. Ginna Nuclear Power Plant Proposed Alternative to Utilize Code Case N-513-4 10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 10 CFR 50.55a(z)(2), Revision 0 (Page 1 of 4)

1. ASME Code Component(s) Affected:

All American Society of Mechanical Engineers (ASME),Section XI, Class 2 and 3 components that meet the operational and configuration limitations of Code Case N-513-4, paragraphs 1 (a), 1 (b), 1 (c), and 1 (d).

2. Applicable Code Edition and Addenda

rurrr INTERVAL EDITION START END Braidwood Station, Third 2001 Edition, through July 29, 2008 July 28, 2018 Units 1 and 2 2003 Addenda October 17, 2008 October 16, 2018 Third 2001 Edition, through January 16, 2006 July 15, 2016 Byron Station, 2003 Addenda Units 1 and 2 2007 Edition, through Fourth 2008 Addenda July 16, 2016 July 15, 2025 Calvert Cliffs Nuclear Power Fourth 2004 Edition October 10, 2009 June 30, 2019 Plant, Units 1 and 2 Clinton Power Station, Unit 1 Third 2004 Edition July 1, 2010 June 30, 2020 Dresden Nuclear Power Fifth 2007 Edition, through January 20, 2013 January 19, 2023 Station, Units 2 and 3 2008 Addenda R. E. Ginna Nuclear Power Fifth 2004 Edition January 1, 201 O December 31, 2019 Plant LaSalle County Stations, Third 2001 Edition, through October 1, 2007 September 30, 2017 Units 1 and 2 2003 Addenda Third 2001 Edition, through February 1, 2007 January 31, 2017 Limerick Generating Station, 2003 Addenda Units 1 and 2 2007 Edition, through Fourth 2008 Addenda February 1, 2017 January 31, 2027 Nine Mile Point Nuclear Fourth 2004 Edition August 23, 2009 August 22, 2019 Station, Unit 1 Nine Mile Point Nuclear Third 2004 Edition April 5, 2008 April 4, 2018 Station, Unit 2 Oyster Creek Nuclear Fifth 2007 Edition, through January 15, 2013 January 14, 2023 Generating Station 2008 Addenda Peach Bottom Atomic Power Fourth 2001 Edition, through November 5, 2008 November 4, 2018 Station, Units 2 and 3 2003 Addenda 10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision O (Page 2 of 4)

PLANT INTERVAL EDITION START Quad Cities Nuclear Power Fifth 2007 Edition, through April 2, 2013 Station, Units 1 and 2 2008 Addenda Three Mile Island Nuclear Fourth 2004 Edition April 20, 2011 Station, Unit 1

3. Applicable Code Requirement

END April 1, 2023 April 19, 2022 ASME Code,Section XI, IWC-3120 and IWC-3130 require that flaws exceeding the defined acceptance criteria be corrected by repair/replacement activities or evaluated and accepted by analytical evaluation. ASME Code,Section XI, IWD-3120(b) requires that components exceeding the acceptance standards of IWD-3400 be subject to supplemental examination, or to a repair/replacement activity.

4. Reason for Request

In accordance with 1 O CFR 50.55a(z)(2), Exelon Generation Company, LLC (Exelon) is requesting a proposed alternative from the requirement to perform repair/replacement activities for degraded Class 2 and 3 piping whose maximum operating temperature does not exceed 200°F and whose maximum operating pressure does not exceed 275 psig 1*

Moderately degraded piping could require a plant shutdown within the required action statement timeframes to repair observed degradation. Plant shutdown activities result in additional dose and plant risk that would be inappropriate when a degraded condition is demonstrated to retain adequate margin to complete the component's function. The use of an acceptable alternative analysis method in lieu of immediate action for a degraded condition will allow Exelon to perform additional extent of condition examinations on the affected systems while allowing time for safe and orderly long term repair actions if necessary. Actions to remove degraded piping from service could have a detrimental overall risk impact by requiring a plant shutdown, thus requiring use of a system that is in standby during normal operation. Accordingly, compliance with the current code requirements results in a hardship without a compensating increase in the level of quality and safety.

ASME Code Case N-513-3 does not allow evaluation of flaws located away from attaching circumferential piping welds that are in elbows, bent pipe, reducers, expanders, and branch tees. ASME Code Case N-513-3 also does not allow evaluation of flaws located in heat exchanger external tubing or piping. ASME Code Case N-513-4 provides guidance for evaluation of flaws in these locations.

1 Peach Bottom Atomic Power Station and Quad Cities Nuclear Power Station have an approved relief request (ADAMS Accession Number ML15043A496) to utilize Code Case N-513-3 at a higher operating pressure than allowed by the Code Case. This relief request to utilize Code Case N-513-4 does not supersede or negate the need for the previous approval contained in ML15043A496.

10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision O (Page 3 of 4)

5. Proposed Alternative and Basis for Use

Exelon is requesting approval to apply the evaluation methods of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," to Class 2 and 3 components that meet the operational and configuration limitations of Code Case N-513-4, paragraphs 1 (a), 1 (b), 1 (c), and 1 (d) in order to avoid accruing additional personnel radiation exposure and increased plant risk associated with a plant shutdown to comply with the cited Code requirements.

The NRC issued Generic Letter 90-05 (Reference 1 ), "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping (Generic Letter 90-05)," to address the acceptability of limited degradation in moderate energy piping. The generic letter defines conditions that would be acceptable to utilize temporary non-code repairs with NRC approval. The ASME recognized that relatively small flaws could remain in service without risk to the structural integrity of a piping system and developed Code Case N-513.

NRC approval of Code Case N-513 versions in Regulatory Guide 1.147, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1," allows acceptance of partial through-wall or through-wall leaks for an operating cycle provided all conditions of the Code Case and NRC conditions are met. The Code Case also requires the Owner to demonstrate system operability due to leakage.

The ASME recognized that the limitations in Code Case N-513-3 were preventing needed use in piping components such as elbows, bent pipe, reducers, expanders, and branch tees and external tubing or piping attached to heat exchangers. Code Case N-513-4 was approved by the ASME to expand use on these locations and to revise several other areas of the Code Case. Attachment 2 provides a marked-up N-513-3 version of the Code Case to highlight the changes compared to the NRC approved N-513-3 version. Attachment 3 provides the ASME approved Code Case N-513-4. The following provides a high level overview of the Code Case N-513-4 changes:

1. Revised the maximum allowed time of use from no longer than 26 months to the next scheduled refueling outage.
2. Added applicability to piping elbows, bent pipe, reducers, expanders, and branch tees where the flaw is located more than (R0t) 112 from the centerline of the attaching circumferential piping weld.
3. Expanded use to external tubing or piping attached to heat exchangers.
4. Revised to limit the use to liquid systems.
5. Revised to clarify treatment of Service Level load combinations.
6. Revised to address treatment of flaws in austenitic pipe flux welds.
7. Revised to require minimum wall thickness acceptance criteria to consider longitudinal stress in addition to hoop stress.
8. Other minor editorial changes to improve the clarity of the Code Case.

Detailed discussion of significant changes in Code Case N-513-4 when compared to NRC approved Code Case N-513-3 is provided in Attachment 4.

10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision 0 (Page 4 of 4)

In summary, Exelon will apply ASME Code Case N-513-4 to evaluation of Class 2 and 3 components that are within the scope of the Code Case. Code Case N-513-4 utilizes technical evaluation approaches that are based on principals that are accepted in other Code documents already acceptable to the NRC. The application of this code case will maintain acceptable structural and leakage integrity while minimizing plant risk and personnel exposure by minimizing the number of plant transients that could be incurred if degradation is required to be repaired based on ASME Section XI acceptance criteria only.

6. Duration of Proposed Alternative

The proposed alternative is for use of Code Case N-513-4 for Class 2 and Class 3 components within the scope of the Code Case. A Section XI compliant repair/replacement will be completed prior to exceeding the next refueling outage or allowable flaw size, whichever comes first. This relief request will be applied for the duration of the inservice inspection interval defined in Section 2 of this relief request or such time as the NRC approves Code Case N-513-4 in Regulatory Guide 1.14 7 or other document. If a flaw is evaluated near the end of the interval for one of the plants in Section 2 and the next refueling outage is in the subsequent interval the flaw may remain in service under this relief request until the next refueling outage.

7. Precedent:

None

8.

Reference:

1.

NRC Generic Letter 90-05, "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping (Generic Letter 90-05)"

201., Exelon W-y Exelon Generation Kennet' Square. PA 19348 www.exe1oni Drp.com 10 CFR 50.55a RS-16-041 January 28, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455 Calvert Cliffs Nuclear Power Plant, Units 1 and 2 Renewed Facility Operating License Nos. DPR-53 and DPR-69 NRC Docket Nos. 50-317 and 50-318 Clinton Power Station, Unit 1 Facility Operating License No. NPF-62 NRC Docket No. 50-461 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-11 and NPF-18 NRC Docket Nos. 50-373 and 50-374 Limerick Generating Station, Units 1 and 2 Renewed Facility Operating License Nos. NPF-39 and NPF-85 NRC Docket Nos. 50-352 and 50-353 Nine Mile Point Nuclear Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-63 and NPF-69 NRC Docket Nos. 50-220 and 50-41 O Oyster Creek Nuclear Generating Station Renewed Facility Operating License No. DPR-16 NRC Docket No. 50-219

U.S. Nuclear Regulatory Commission Proposed Alternative to Utilize Code Case N-513-4 January 28, 2016 Page 2

Subject:

Peach Bottom Atomic Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-44 and DPR-56 NRC Docket Nos. 50-277 and 50-278 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265 R.E. Ginna Nuclear Power Plant Renewed Facility Operating License No. DPR-18 NRC Docket No. 50-244 Three Mile Island Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-50 NRC Docket No. 50-289 Proposed Alternative to Utilize Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1 "

In accordance with 10 CFR 50.55a(z)(2), Exelon Generation Company, LLC (Exelon) is requesting a proposed alternative to the American Society of Mechanical Engineers (ASME)

Boiler and Pressure Vessel Code,Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components," on the basis that compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Specifically, Exelon is requesting to apply the evaluation methods of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," to Class 2 and 3 moderate energy piping including elbows, bent pipe, reducers, expanders, and branch tees.

Peach Bottom Atomic Power Station and Quad Cities Nuclear Power Station have an approved relief request (ADAMS Accession Number ML15043A496) to utilize Code Case N-513-3 at a higher operating pressure than allowed by the Code Case. This relief request to utilize Code Case N-513-4 does not supersede or negate the need for the previous approval contained in ML15043A496. This relief request to utilize Code Case N-513-4 will only be applied to systems/components that meet the applicability conditions in Code Case N-513-4.

There are no commitments contained in this submittal.

U.S. Nuclear Regulatory Commission Proposed Alternative to Utilize Code Case N-513-4 January 28, 2016 Page 3 We request your review and approval of this multi-site request by January 28, 2017.

Respectfully,

~c- )1.'.,j_.)r--

David T. Gudger Manager - Licensing and Regulatory Affairs Exelon Generation Company, LLC Attachments: 1) Proposed Alternative to Utilize Code Case N-513-4

2) Marked-up Version of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1"
3) ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1"
4) Technical Basis for Proposed Fourth Revision to ASME Code Case N-513 cc:

Regional Administrator - NRC Region I Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Braidwood Station NRC Senior Resident Inspector - Byron Station NRC Senior Resident Inspector - Clinton Power Station NRC Senior Resident Inspector - Dresden Nuclear Power Station NRC Senior Resident Inspector - LaSalle County Station NRC Senior Resident Inspector - Limerick Generating Station NRC Senior Resident Inspector - Oyster Creek Nuclear Generating Station NRC Senior Resident Inspector - Peach Bottom Atomic Power Station NRC Senior Resident Inspector - Quad Cities Nuclear Power Station NRC Senior Resident Inspector - Three Mile Island Nuclear Station, Unit 1 NRC Senior Resident Inspector - Calvert Cliffs Nuclear Power Plant NRC Senior Resident Inspector - Nine Mile Point Nuclear Station NRC Senior Resident Inspector - R.E. Ginna Nuclear Power Plant NRC Project Manager - Braidwood Station NRC Project Manager - Byron Station NRC Project Manager - Clinton Power Station NRC Project Manager - Dresden Nuclear Power Station NRC Project Manager - LaSalle County Station NRC Project Manager - Limerick Generating Station NRC Project Manager - Oyster Creek Nuclear Generating Station NRC Project Manager - Peach Bottom Atomic Power Station NRC Project Manager - Quad Cities Nuclear Power Station NRC Project Manager - Three Mile Island Nuclear Station, Unit 1 NRC Project Manager - Calvert Cliffs Nuclear Power Plant NRC Project Manager - Nine Mile Point Nuclear Station NRC Project Manager - R.E. Ginna Nuclear Power Plant Proposed Alternative to Utilize Code Case N-513-4 10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 10 CFR 50.55a(z)(2), Revision 0 (Page 1 of 4)

1. ASME Code Component(s) Affected:

All American Society of Mechanical Engineers (ASME),Section XI, Class 2 and 3 components that meet the operational and configuration limitations of Code Case N-513-4, paragraphs 1 (a), 1 (b), 1 (c), and 1 (d).

2. Applicable Code Edition and Addenda

rurrr INTERVAL EDITION START END Braidwood Station, Third 2001 Edition, through July 29, 2008 July 28, 2018 Units 1 and 2 2003 Addenda October 17, 2008 October 16, 2018 Third 2001 Edition, through January 16, 2006 July 15, 2016 Byron Station, 2003 Addenda Units 1 and 2 2007 Edition, through Fourth 2008 Addenda July 16, 2016 July 15, 2025 Calvert Cliffs Nuclear Power Fourth 2004 Edition October 10, 2009 June 30, 2019 Plant, Units 1 and 2 Clinton Power Station, Unit 1 Third 2004 Edition July 1, 2010 June 30, 2020 Dresden Nuclear Power Fifth 2007 Edition, through January 20, 2013 January 19, 2023 Station, Units 2 and 3 2008 Addenda R. E. Ginna Nuclear Power Fifth 2004 Edition January 1, 201 O December 31, 2019 Plant LaSalle County Stations, Third 2001 Edition, through October 1, 2007 September 30, 2017 Units 1 and 2 2003 Addenda Third 2001 Edition, through February 1, 2007 January 31, 2017 Limerick Generating Station, 2003 Addenda Units 1 and 2 2007 Edition, through Fourth 2008 Addenda February 1, 2017 January 31, 2027 Nine Mile Point Nuclear Fourth 2004 Edition August 23, 2009 August 22, 2019 Station, Unit 1 Nine Mile Point Nuclear Third 2004 Edition April 5, 2008 April 4, 2018 Station, Unit 2 Oyster Creek Nuclear Fifth 2007 Edition, through January 15, 2013 January 14, 2023 Generating Station 2008 Addenda Peach Bottom Atomic Power Fourth 2001 Edition, through November 5, 2008 November 4, 2018 Station, Units 2 and 3 2003 Addenda 10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision O (Page 2 of 4)

PLANT INTERVAL EDITION START Quad Cities Nuclear Power Fifth 2007 Edition, through April 2, 2013 Station, Units 1 and 2 2008 Addenda Three Mile Island Nuclear Fourth 2004 Edition April 20, 2011 Station, Unit 1

3. Applicable Code Requirement

END April 1, 2023 April 19, 2022 ASME Code,Section XI, IWC-3120 and IWC-3130 require that flaws exceeding the defined acceptance criteria be corrected by repair/replacement activities or evaluated and accepted by analytical evaluation. ASME Code,Section XI, IWD-3120(b) requires that components exceeding the acceptance standards of IWD-3400 be subject to supplemental examination, or to a repair/replacement activity.

4. Reason for Request

In accordance with 1 O CFR 50.55a(z)(2), Exelon Generation Company, LLC (Exelon) is requesting a proposed alternative from the requirement to perform repair/replacement activities for degraded Class 2 and 3 piping whose maximum operating temperature does not exceed 200°F and whose maximum operating pressure does not exceed 275 psig 1*

Moderately degraded piping could require a plant shutdown within the required action statement timeframes to repair observed degradation. Plant shutdown activities result in additional dose and plant risk that would be inappropriate when a degraded condition is demonstrated to retain adequate margin to complete the component's function. The use of an acceptable alternative analysis method in lieu of immediate action for a degraded condition will allow Exelon to perform additional extent of condition examinations on the affected systems while allowing time for safe and orderly long term repair actions if necessary. Actions to remove degraded piping from service could have a detrimental overall risk impact by requiring a plant shutdown, thus requiring use of a system that is in standby during normal operation. Accordingly, compliance with the current code requirements results in a hardship without a compensating increase in the level of quality and safety.

ASME Code Case N-513-3 does not allow evaluation of flaws located away from attaching circumferential piping welds that are in elbows, bent pipe, reducers, expanders, and branch tees. ASME Code Case N-513-3 also does not allow evaluation of flaws located in heat exchanger external tubing or piping. ASME Code Case N-513-4 provides guidance for evaluation of flaws in these locations.

1 Peach Bottom Atomic Power Station and Quad Cities Nuclear Power Station have an approved relief request (ADAMS Accession Number ML15043A496) to utilize Code Case N-513-3 at a higher operating pressure than allowed by the Code Case. This relief request to utilize Code Case N-513-4 does not supersede or negate the need for the previous approval contained in ML15043A496.

10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision O (Page 3 of 4)

5. Proposed Alternative and Basis for Use

Exelon is requesting approval to apply the evaluation methods of ASME Code Case N-513-4, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1," to Class 2 and 3 components that meet the operational and configuration limitations of Code Case N-513-4, paragraphs 1 (a), 1 (b), 1 (c), and 1 (d) in order to avoid accruing additional personnel radiation exposure and increased plant risk associated with a plant shutdown to comply with the cited Code requirements.

The NRC issued Generic Letter 90-05 (Reference 1 ), "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping (Generic Letter 90-05)," to address the acceptability of limited degradation in moderate energy piping. The generic letter defines conditions that would be acceptable to utilize temporary non-code repairs with NRC approval. The ASME recognized that relatively small flaws could remain in service without risk to the structural integrity of a piping system and developed Code Case N-513.

NRC approval of Code Case N-513 versions in Regulatory Guide 1.147, "lnservice Inspection Code Case Acceptability, ASME Section XI, Division 1," allows acceptance of partial through-wall or through-wall leaks for an operating cycle provided all conditions of the Code Case and NRC conditions are met. The Code Case also requires the Owner to demonstrate system operability due to leakage.

The ASME recognized that the limitations in Code Case N-513-3 were preventing needed use in piping components such as elbows, bent pipe, reducers, expanders, and branch tees and external tubing or piping attached to heat exchangers. Code Case N-513-4 was approved by the ASME to expand use on these locations and to revise several other areas of the Code Case. Attachment 2 provides a marked-up N-513-3 version of the Code Case to highlight the changes compared to the NRC approved N-513-3 version. Attachment 3 provides the ASME approved Code Case N-513-4. The following provides a high level overview of the Code Case N-513-4 changes:

1. Revised the maximum allowed time of use from no longer than 26 months to the next scheduled refueling outage.
2. Added applicability to piping elbows, bent pipe, reducers, expanders, and branch tees where the flaw is located more than (R0t) 112 from the centerline of the attaching circumferential piping weld.
3. Expanded use to external tubing or piping attached to heat exchangers.
4. Revised to limit the use to liquid systems.
5. Revised to clarify treatment of Service Level load combinations.
6. Revised to address treatment of flaws in austenitic pipe flux welds.
7. Revised to require minimum wall thickness acceptance criteria to consider longitudinal stress in addition to hoop stress.
8. Other minor editorial changes to improve the clarity of the Code Case.

Detailed discussion of significant changes in Code Case N-513-4 when compared to NRC approved Code Case N-513-3 is provided in Attachment 4.

10 CFR 50.55a RELIEF REQUEST:

Request to Use Code Case N-513-4 in Accordance with 1 O CFR 50.55a(z)(2), Revision 0 (Page 4 of 4)

In summary, Exelon will apply ASME Code Case N-513-4 to evaluation of Class 2 and 3 components that are within the scope of the Code Case. Code Case N-513-4 utilizes technical evaluation approaches that are based on principals that are accepted in other Code documents already acceptable to the NRC. The application of this code case will maintain acceptable structural and leakage integrity while minimizing plant risk and personnel exposure by minimizing the number of plant transients that could be incurred if degradation is required to be repaired based on ASME Section XI acceptance criteria only.

6. Duration of Proposed Alternative

The proposed alternative is for use of Code Case N-513-4 for Class 2 and Class 3 components within the scope of the Code Case. A Section XI compliant repair/replacement will be completed prior to exceeding the next refueling outage or allowable flaw size, whichever comes first. This relief request will be applied for the duration of the inservice inspection interval defined in Section 2 of this relief request or such time as the NRC approves Code Case N-513-4 in Regulatory Guide 1.14 7 or other document. If a flaw is evaluated near the end of the interval for one of the plants in Section 2 and the next refueling outage is in the subsequent interval the flaw may remain in service under this relief request until the next refueling outage.

7. Precedent:

None

8.

Reference:

1.

NRC Generic Letter 90-05, "Guidance for Performing Temporary Non-Code Repair of ASME Code Class 1, 2, and 3 Piping (Generic Letter 90-05)"

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