RA-19-0425, License Renewal Surge Line and Safety Injection Nozzle Inspection

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License Renewal Surge Line and Safety Injection Nozzle Inspection
ML20157A077
Person / Time
Site: Mcguire, McGuire  Duke Energy icon.png
Issue date: 05/17/2020
From: Teresa Ray
Duke Energy Carolinas
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
RA-19-0425
Download: ML20157A077 (14)
v • d • e


Text

e.{_--. DUKE Thomas D. Ray, P.E.

Site Vice President

"'e'" ENERGY McGuire Nuclear Station Duke Energy MG01VP I;~ 12700 Hagers Ferry Road Huntersville, NC 28078 o: 980.875.4805

f: 980.875.4809 Torn.Ray@duke-energy.com Serial: RA-19-0425 May 17, 2020 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

SUBJECT:

Duke Energy Carolinas, LLC (Duke Energy)

McGuire Nuclear Station, Units 1 and 2 Facility Operating License Numbers NPF-9 and NPF-17 Docket Numbers 50-369 and 50-370 License Renewal Surge Line and Safety Injection Nozzle:;lnspection

REFERENCES:

1. NRG Letter to Duke Energy, License Renewal Safety ££valuation Report for McGuire, Units 1 and 2, and Catawba, Units 1 and 2, datedI January 6, 2003 (ML030030122)
2. NUREG-1772, Safety Evaluation Report Related to the License Renewal of McGuire Nuclear Station, Units 1 and 2, and Catawba :Nuclear Station, Units 1 and 2 (ML030850251)
  • Per the above references, Duke Energy Corporation (Duke) is committecl to address the effects of environmentally-assisted fatigue (EAF) for several fatigue-sen~itive locations, including the pressurizer surge line and safety injection nozzle, during the period of extended operations. As stated in Reference 2:

The applicant agreed not to use the flaw tolerance/inspection procedure$ specified in Note 1 unless such procedures have been accepted by the NRG.

Duke intends to manage the aging effects of EAF on the pressurizer surge line and safety injection nozzle through flaw tolerance evaluation and inspections. Accordingly, Enclosure 1 provides the description of the flaw tolerance evaluation and proposed inspections for NRC Staff review and approval.

U.S. Nuclear Regulatory Commission Document Control Desk Serial: RA-19-0425 Page2 There are no new regulatory commitments contained in this letter. Questions regarding this submittal should be directed to Jeff Thomas at (980) 875-4499.

  • Sincerely, Thomas D. Ray, P.E.

Site Vice President McGuire Nuclear Station

Enclosure:

1. Description of the Proposed Method to Manage Aging due to Entironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety Injection Nozzie

U.S. Nuclear Regulatory Commission Document Control Desk Serial: RA-19-0425 Page3 cc: w/Enclosure Laura A. Dudes, Regional Administrator U.S. Nuclear Regulatory Commission Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, Georgia 30303-1257 Andy Hutto, Senior Resident Inspector U.S. Nuclear Regulatory Commission McGuire Nuclear Station Michael Mahoney, Project Manager U.S. Nuclear Regulatory Commission 11555 Rockville Pike Mail Stop O-8B1A Rockville, MD 20852

Serial RA-19-0425 Page 1 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Ervironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj~ction Nozzle

1. BACKGROUND The Duke Energy Corporation (Duke) license renewal application for ~cGuire, Units 1 and 2, and Catawba, Units 1 and 2 (Reference 5.1) identified the effects of environmentally-assisted fatigue (EAF) as an issue and stated in Section 4.3.1.2:
  • II However, since NUREGICR-6674 [Reference 4.3- 5) indicated that fatigue reactor coolant environmental effects would result in an increased frequency of pipe leakage, the NRG required that utilities applying for license renewal ad~ress the effects of reactor water environment on fatigue usage in affected components. II Duke proposed the following approach:
1. Choose 6-1 O plant locations for assessment.
2. For an evaluation period, determine the EAF-adjusted Cumulative Usage Factor (CUF)at these locations, using defined transient severities and/or assur1,ed occurrences either bounding or coinciding with realistic expectations.  :
3. Within the evaluation period, continually track the fatigue accu\jnulating at the locations.
4. Compare either the recorded incidences of occurring transient$ with the number used in step 2, or compare the calculated EAF-adjusted CUF with that;;predicted in step 2.
5. Make future projections of either the EAF-adjusted CUF or the;:count of transient occurrences to determine the remaining time to reaching the ailowables.

Note 1 to this strategy indicated that if the EAF-adjusted CUF could nc!it II be shown to remain below 1.0 then the alternatives from Draft EPRI Report, Guideli,:,es folf; Addressing Fatigue Environmental Effects in a License Renewal Application, Electric Power Research Institute, (including Flaw Tolerance and Inspection) would be used.

For McGuire Units 1 and 2 (MNS), the critical locations of concern for fatigue cumulative usage factor (CUFen) are the Hot Leg Surge Nozzle and the boron injection n;ozzle (References 5.3 and 5.4). The calculated CUFen values for these locations were determ,ined to exceed the ASME Code allowable usage factor of 1.0 when EAF is considered during th~ Period of Extended Operation (PEO). '!

In the Safety Evaluation Report (Reference 5.2) it states:

The applicant agreed not to use the flaw tolerance/inspection procedures specified in Nate 1 unless such procedures have been accepted by the Nfi,C. In addition, the applicant agreed to revise the procedure specified in LRA Section 4.3.1.2 to set Z equal to 1.0. The staff finds these commitments acceptable.

Duke intends to manage the aging effects associated EAF on the pre~1surizer surge line and the safety injection nozzle with a combination of inspections and flaw toler:ance evaluation.

Accordingly, Sections 2, 3, and 4 provide the flaw tolerance evaluation description, inspection attributes, and implementation plan for NRC Staff review and approval:.

Serial RA-19-0425 Page 2 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to E~vironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj~ction Nozzle

2. FLAW TOLERANCE EVALUATION DESCRIPTION The MNS pressurizer surge line and safety injection nozzle evaluation$ are based on the flaw tolerance approach documented in the ASME Boiler and Pressur,e Ve$sel Code,Section XI -

Rules for lnservice Inspection (ISi) of Nuclear Power Plant Componen;~s, Non-Mandatory Appendix L, Operating Plant Fatigue Assessment. I!

The evaluations were performed in accordance with the requirements hf the 2013 Edition of the ASME Code,Section XI, Appendix L. Effective August 17, 2017, the l~test II ASME Code edition approved by the NRC is the 2013 Edition, which includesSection XI, Appendix L. Code Case N-809, which includes the latest crack growth data, has been approvep by ASME. At this time Code Case N-809 has not been officially endorsed by the NRC. Ho " er, the NRC has reviewed and approved precedent license renewal commitments pert , ning to fatigue for Turkey Point (Submittal: ML12152A156 and Approval: ML13141A595) and St/ Lucie (Submittal:

1 ML15314A160 and Approval: ML16235A138) using Code Case N-809,.

2.1 ASME Section XI Appendix L Analysis of the Pressurizer Surge Li~e ii JI The fatigue flaw tolerance evaluation was performed specifically for MNS to assess the operability of the surge line by using ASME Section XI, Appendix L m~thodology and to determine the successive inspection interval for the surge line with a Rpstulated surface-connected flaw. Based on fatigue usage, the Hot Leg Surge Nozzle and Pressurizer Surge Nozzle were selected as the evaluation locations for the allowable flaJIi size determination. Both fixed and variable flaw aspect ratios were evaluated. The hot leg nozzle weld location was shown to be bounding, reaching the allowable flaw depth in approxim~tely 11 years. The pressurizer nozzle takes at least 33 years to reach the allowable flaw ~epth. The results of the crack growth for the Pressurizer Surge Nozzle welds and Hot Leg Sur4e Nozzle welds are presented in Tables 1 and 2, respectively. "

(References 5.5, 5.6, 5. 7)

Table 1

,I Pressurizer Surge Nozzle Weld Crack Growth Results I

Allowable Successive Aspect Final Flaw Size Allowable Operating Inspection Flaw Type !j Ratio alt Period Schedule

,i a c, inch e, inch t, deg. alt vears years Axial Fixed 0.3212 5.8400 11.6800 -- 0.2284 0.2322:1 33 10 Variable 0.4124 3.7170 7.4340 --- 0.2933 0.2951:: 59 10 Circumferential N/A 0.3785 8.8023 17.6047 180.31 0.2682 0.2698!1 53 10

Serial RA-19-0425 Page 3 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Environmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj~ction Nozzle Table 2 Hot Leg Surge Nozzle Weld Crack Growth Res:ults II

!! Allowable Successive Aspect Final Flaw Size Allowable Operating Inspection Flaw Type Ratio alt II Period Schedule a, inch c, inch e,inch e, deg. alt II years years Axial Fixed 0.3196 5.8109 11.6218 -- 0.2273 0.2328'! 12 10 Variable 0.4019 3.7191 7.4382 .----- 0.2858 0.295Ci: 21 10 Circumferential NIA 0.3847 7.6940 15.3880 157.61 0.2736 0.2949.: 11 10 2.2 ASME Section XI Appendix L Analysis of the MNS Safety lnjectio~j Nozzle II A fatigue flaw tolerance evaluation was performed specifically for MNS, to assess the operability of the safety injection nozzle by using ASME Section XI, Appendix L, rpethodology and to determine the successive inspection interval for the safety injection nozzle with a postulated surface-connected flaw. Both the axial and circumferential flaws were kcceptable for 60 years of operation, with the a/t ratio well below the allowable values. The results of the crack growth for the safety injection nozzle are presented in Table 3. II (References 5.8, 5.9, 5.10)

Table 3 Safety Injection Nozzle Crack Growth Result~

!i Allowable Successive Final Flaw Size Allowable Operating Inspection Flaw Type alt Period Schedule a, inch c, inch e, inch t, deg. alt years years Axial 0.0472 0.1975 0.3950 -- 0.1680 0.75 60 10 Circumferential 0.0427 0.2033 0.4066 34.82 0.1519 0.75 60 10 2.3 Inspection Schedule Per the guidelines of Appendix L, Table L-3420-1, for the allowable opprating periods listed in

  • Tables 1, 2 and 3, the successive inspection schedule for pressurizer $Urge line welds and the safety injection nozzle is determined to be ten years for either an axial 11 or a circumferential postulated flaw. This inspection interval will be used for all pressurizensurge line welds and the safety injection nozzle as noted in Table 4 and Table 5.  :

Serial RA-19-0425 Page 4 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to E~vironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj~ction Nozzle

3. INSPECTION PROGRAM ATTRIBUTES The attributes of the MNS Pressurizer Surge Line and Safety Injection: Nozzle Inspection Program are discussed below: i
1. Scope of the Inspections The pressurizer surge line and safety injection nozzle welds listed in Table 4, MNS Pressurizer Surge Line Welds - Inspection Summary and Tabl,¢ 5, Safety Injection Nozzles - Inspection Summary will be examined in accordan~ ASME Section XI, IWB under the MNS Risk-Informed ISi Program for Class 1 welds (~eferences 5.11 and 5.12). The aging effect managed with these inspections is cra*ing due to environmentally-assisted fatigue. In each 10-year ISi interval d,µring the period of extended operation, the bounding pressurizer surge line locatic?n for each unit will be inspected (RCS Hot Leg Surge Nozzle weld) as well as Pipe tQ Pressurizer Nozzle welds in accordance with the MNS ISi Program. The eight Saf~ty Injection Nozzle welds (four per unit) will also be inspected. .

Based on the flaw tolerance analyses, and per the guidelines qf ASME Code,Section XI, Appendix L, Table L-3420-1, the successive inspection schedy,le is determined to be ten years. This inspection interval will be used for all welds in scop 1

r.

I\

Examination methods are determined in accordance with the requirements of the Risk Informed lnservice Inspection (RI-ISi) Programs for Class 1 piRing welds. lnservice Inspection of ASME Class 1 and 2 piping welds at McGuire (C1;,1tegories 8-F, B-J, C-F-1 and C-F-2) is being performed in accordance with a Risk Informed lnservice Inspection (RI-ISi) Program per Section XI Code Case N-716 and associ~:fred Relief Request 13-MN-002. The Risk Informed Program does not require a su~ace examination to be performed for these category welds. Examination results are etaluated by qualified individuals in accordance with ASME Section XI acceptance cr,jteria. Components with indications that do not exceed the acceptance criteria are considered acceptable for continued service. *

2. Preventive Actions There are no specific preventive actions under this program to !prevent the effects of aging. *
3. Parameter(s) Monitored or Inspected lnservice examinations for the Pressurizer Surge Line and Saf~ty Injection Nozzle welds will be volumetric examinations as indicated in Table 4 and Table 5.

Serial RA-19-0425 Page 5 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Ervironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety Injection Nozzle

4. Detection of Aging Effects The management of degradation of the surge line and safety i1;1jection nozzle welds is accomplished by volumetric examination in accordance with th b requirements of the 4

MNS ISi Program. The frequency and scope of examinations are demonstrated to be sufficient to ensure that aging effects are detected before the i~tegrity of the surge line or 11 safety injection nozzle would be compromised.

5. Monitoring and Trending The frequency and scope of the examinations are sufficient to ~nsure that the environmentally-assisted fatigue aging effect is detected before, the intended function of these welds would be compromised. Examinations will be perf~rmed in accordance with the inspection intervals based on the results of the postulated f:!aw evaluation performed in accordance to the ASME Code Section XI, Appendix L methodology.

Flaws identified in the pressurizer surge line or safety injection Jjnozzle welds will be evaluated by engineering to assess the effect of EAF and to de,termine impacts on the EAF analysis.

  • Records of the examination procedures, results of activities, e~amination datasheets, and corrective actions taken or recommended will be maintained in accordance with the requirements of MNS ISi Program and ASME Section XI. "
6. Acceptance Criteria Acceptance standards for the ISi examinations are identified in., Subsection IWB for Class 1 components. Table IWB-2500-1 identifies references t~ acceptance standards listed in IWB-3500. Flaws found in the surge line elbow or safety injection nozzle welds that are revealed by the volumetric examination require additional evaluation per the requirements of ASME Section XI.

Flaws that exceed the acceptance criteria will be entered into the Duke Corrective Action Program. Acceptance for continued service of surge line elbowl!or safety injection nozzle welds with flaws that do not meet the acceptance standards ofASME Section XI, IWB-3500, will be corrected either by repair, replacement or analytid~I evaluation.

Repairs or replacements will be performed in accordance with ~SME Section XI, Subsection IWA-4000, as described in administrative procedur~ AD-EG-ALL-1703, ASME Section XI Repair/Replacement Program Administration~

7. Corrective Actions Action Requests are generated in accordance with the Duke C9rrective Action Program for flaws that exceed the acceptance criteria. Items with examination results that do not meet the acceptance criteria are subject to acceptance by analytical evaluation per

Serial RA-19-0425 Page 6 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Environmentally Assisted Fatigue for the Pressurizer Surge Line and Safety Injection Nozzle subsection IWB-3600 and/or acceptance by repair or replacement in accordance with Subsection IWA-4000.

8. Confirmation Process When degradation is identified in the pressurizer surge line or safety injection nozzle welds, an engineering evaluation is performed to determine if they are acceptable for continued service or if repair or replacement is required. The engineering evaluation includes probable cause, the extent of degradation, the nature and frequency of additional examinations, and, whether repair or replacement is required.

Repair and replacement are performed in accordance with the requirements of ASME Section XI, Subsection IWA-4000, and as implemented by MNS administrative procedure AD-EG-ALL-1703, ASME Section XI Repair/Replacement Program Administration.

9. Administrative Controls The MNS ISi Program will document the EAF inspection requirements for the MNS pressurizer surge line and safety injection nozzle welds under the ASME Section XI ISi Program. Site Quality Assurance procedures, review and approval processes, and administrative controls are implemented in accordance with the requirements of Appendix B of 10 CFR Part 50 and will continue to be adequate for the PEO.

Procedures utilized include:

( 1) AD-PI-ALL-0100, Corrective Action Program (2) AD-EG-ALL-1702, ASME Section XI lnservice Inspection Program Administration (3) AD-EG-ALL-1703, ASME Section XI Repair/Replacement Program Administration

10. Operating Experience A sample of the surge line welds have been examined ultrasonically during the first four ISi intervals in accordance with the requirements of ASME Section XI, Subsection IWB with no relevant indications reported. The most recent inspections were performed on the Reactor Coolant System (NC) Hot Leg Surge Nozzle weld in 2010 and 2009 for Units 1 and 2, respectively. The Pipe to Pressurizer Nozzle welds were inspected in 2017 and 2018 for Units 1 and 2, respectively.

Since Spring 2014, the safety injection lines have had multiple piping flaws in normally isolated NC branch piping. These Code rejectable flaws were attributed to high cycle thermal fatigue due to reactor coolant system swirl penetration acting in concert with cold water inleakage. A description of these incidences is described below.

LER 370/2014-01 describes a rejectable flaw in the Unit 2 D Loop Safety Injection Nozzle. Actions were taken to repair the piping and to re-inspect other susceptible lines before the unit restarted from its refueling outage. Corrective actions included removal of

Serial RA-19-0425 Page 7 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Environmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj;~ction Nozzle a cold leg isolation valve on both units known to have legacy l~akage issues. The cause was attributed to a legacy issue with leakage through the Unit 2 NC Cold Leg Injection line from a Chemical and Volume Control System (NV) isolatiQ,n valve that created the high frequency thermal cycle condition which initiated the cold::leg nozzle fatigue cracks.

LER 369/2014-02 describes two rejectable flaws on the Unit 1 ,iB and C Loop safety injection lines during the Fall 2014 Outage. Actions were take11 to repair the piping and to inspect other susceptible lines before the unit restarted from1 its refueling outage. As part of planned corrective actions, valves with the potential to <;rause cold water inleakage to these lines were to be monitored for leakage. A legacy issue with leakage through Unit 1 NC Cold Leg Injection from NV isolation valve created the high frequency thermal cycle condition which initiated the cold leg nozzle fatig1,-1e cracks.

LER 370/2017-01 describes that while operating at 100% pow$r in February 2017 operators commenced a Unit 2 shutdown upon discovery of pressure boundary leakage on Unit 2 Safety Injection (NI) pipe upstream of the connection to "D" Reactor Coolant System (NC) Cold Leg. The cause of the NI pipe leak is thermal fatigue damage caused by NC cross-loop flows. The NI piping and B Loop check valve~ were replaced. Leakage testing and thermocouple data confirmed the RCS loop check yalves as the source of leakage resulting in thermal fatigue damage in the Unit 2 D Loop Safety Injection line and was determined to be a contributing cause of this event. These causes represented previously unobserved fatigue cracking operating experience QY the industry and was not addressed by the industry guidance at the time.*

  • Modifications were performed to add a pressure bleed off line to prevent check valve leakage from migrating to the hot RCS nozzles. Industry guida~ce was first updated on an interim basis by MRP 2015-019 to provide new NEI 03-08 N,eeded and Good Practice guidance requirements that supplemented existing thermal fatigue management guidelines for normally isolated Reactor Coolant System branch lines and Residual Heat Removal (RHR) system mixing tees. MRP-146, Revision 2 wai;, released and incorporated the interim guidance requirements. Subsequently'MRP 2019-008 was issued as a result of recent industry operating experience of th~rmal fatigue, particularly regarding cross-flow inleakage which was previously not expeQted to occur during normal operation. This guidance required an update to the examination scope.

All Safety Injection Nozzle welds were inspected in 2017 and 2018 for Units 1 and 2, respectively with no recordable indications. These welds are cqrrently being managed in accordance with MRP-146.

The programmatic operating experience activities described in :,relevant station procedures ensure the adequate evaluation of operating experience on an ongoing basis to address age-related degradation and aging management for: the pressurizer surge line and safety injection nozzles.

The MNS pressurizer surge line operating experience aligns with industry operating experience for Turkey Point Units 3 and 4 (ML12152A156), St. :Lucie (ML15314A160)

Serial RA-19-0425 Page 8 of 11 Enclosure 1 II II Description of the Proposed Method to Manage Aging due to E~vironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj~ction Nozzle and Arkansas Nuclear One, Unit 2 (ML18144A970) as describ$d in their submittals to manage the effects of aging due to EAF through a combination! of inspections and flaw tolerance evaluations.  :

The proposed inspections to examine the hot leg surge nozzle j~elds and safety injection nozzle welds listed in Table 4 and Table 5, for ISi intervals liste;d in the schedule of inspections in accordance with IWB-2410, provides reasonabl~ assurance that potential environmental effects of fatigue will be managed such that the pressurizer surge line and safety injection nozzles will continue to perform their intended fµnction throughout the period of extended operation. *

4. IMPLEMENTATION PLAN 1

Upon approval of the propo~ed inspection program, related aging man agement program basis and implementing documents and the associated Updated Final Safefy Analysis Report (UFSAR) sections will be updated accordingly.  :

. 1i II

Serial RA-19-0425 Page 9 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Ehvironmentally Assisted Fatigue for the Pressurizer Surge Line and Safety lnj:¢ction Nozzle l

5. REFERENCES 5.1 Letter from M.S. Tuckman (Duke) to USNRC, Application to Rerl,ew the Operating Licenses of McGuire Nuclear Station, Units 1 & 2 and Catawba ~uclear Station, Units 1 & 2, Docket Nos. 50-369, 50-370, 50-413 and 50-414, dated June 13, 2001 5.2 NUREG-1772, Safety Evaluation Report Related to the License F.:enewal of McGuire Nuclear Station, Units 1 and 2, and Catawba Nuclear Station, U~its 1 and 2, March 2003 (ACN: ML030850251) 5.3 MCC-1206.02-45-0019, Environmentally Assisted Fatigue Screening for McGuire (SIA File No. 1600302.301) ,

5.4 MCC-1206.02-45-0020, McGuire EAF Sentinel Location Optimal Dispositions (SIA File No.

1700310.301) 1i

  • 5.5 MCC-1206.02-45-0027, Allowable Flaw Size Determination for t~e Surge Line (SIA File No. 1800357.322)  :

5.6 MCC-1206.02-45-0028, Crack Growth Evaluation of the Pressurjzer Surge Line (SIA File No. 1800357.323) :1 5.7 MCC-1206.02-45-0029, Flaw Tolerance Evaluation of the McGu!,re Pressurizer Surge Line using ASME Code Section XI, Appendix L (SIA File No. 180035?.401) 5.8 MCC-1206.02-45-0031, Allowable Flaw Size Determination fortlf:te 1.5" Boron Injection Nozzle (SIA File No. 1800357.326)  :

1 5.9 MCC-1206.02-45-0032, Crack Growth Evaluation of the 1.5-inch' Cold Leg Boron Injection Line Nozzle (SIA File No. 1800357.327)  :

5.10 MCC-1206.02-45-0033, Flaw Tolerance Evaluation of McGuire Boron Injection Nozzles using ASME Code Section XI, Appendix L (SIA File No. 1800357:.402) 5.11 MISl-1462.10-0040 GEN REQ UNIT, Fourth Interval lnservice ln!spection Plan McGuire Nuclear Station Units 1 and 2  :

5.12 MISl-1462.10-0040AUGISI-U1 &U2, McGuire Nuclear Station - F,purth Interval Augmented lnservice Inspection Plan and Schedule 5.13 Letter from R.T. Repko (Duke) to USN RC, Duke Energy Carolinas, LLC (Duke Energy),

McGuire Nuclear Station, Units 1 and 2, Docket Nos. 50-369 antj 50-370, Relief Request Serial # 11-MN-001, Limited Weld Examinations for Refueling O~tages 1EOC20 and 2EOC19, dated September 21, 2011 (ACN: ML11279A035)  ;:

5.14 Letter from USNRC to S.D. Capps (Duke), McGuire Nuclear Sta~ion, Units 1 And 2, .

1 Proposed Relief Request 11-MN-001 (TAC NOS. ME7268, ME7?69, ME7270, ME7271, ME7272, ME7273, AND ME7274), dated September 13, 2012 (~CN: ML12250A401)

Serial RA-19-0425 Page 10 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Environmentally Assisted Fatigue for the Pressurizer Surge Line and Safety Injection Nozzle Table 4 MNS Pressurizer Surge Line Welds - Inspection Summary Allowable Proposed Last Operating Weld Inspections Examination Period per Unit No. or During PEO Performed ASMEApp.

Component Type/

and Results L Analysis Frequency (See Note 1) 1NC1 FW53-NW6 Volumetric Once 2017 Greater than 1 Pipe to Pressurizer per interval not to Satisfactory 10 years Nozzle exceed 10 years 1

1NC1 F3613-3092 2010 Volumetric Once Greater than 2 RCS Hot Leg Surge Satisfactory per interval not to 10 years Nozzle (See Note 2) exceed 1O years 2NC2FW2-NW6 Volumetric Once 2018 Greater than 1 Pipe to Pressurizer per interval not to Satisfactory 10 years Nozzle exceed 10 years 2

2NC2FW2-2 2009 Volumetric Once Greater than 2 RCS Hot Leg Surge Satisfactory per interval not to 10 years Nozzle (See Note 2) exceed 10 years Note 1: The inspection frequency as determined by ASME Code Sectipn XI, Appendix L analysis is more than 10 years. In accordance to the requirements of Appendix L Table L-3420-1, the surge line welds will be examined once per 10 years, at the frequency of the McGuire Nuclear Station lnservice Inspection Interval.

Note 2: This weld was the subject of McGuire Relief Request 11-MN-001 (Reference 5.13) that was approved by Reference 5.14.

Serial RA-19-0425 Page 11 of 11 Enclosure 1 Description of the Proposed Method to Manage Aging due to Environmentally Assisted Fatigue for the Pressurizer Surge Line and Safety Injection Nozzle Table 5 MNS Safety Injection Nozzle Welds - Inspection Summary Allowable Proposed Last Operating Weld Inspections Examination Period per Unit No. or During PEO Performed ASMEApp.

Component Type/

and Results L Analysis Frequency (See Note 1)

Volumetric Once Cold Leg 1A 2017 Greater than 1

Nozzle 1-1 Satisfactory 10 years per interval not to exceed 10 years Volumetric Once Cold Leg 1B 2017 Greater than 2

Nozzle 2-1 Satisfactory 10 years per interval not to exceed 10 years 1

Volumetric Once Cold Leg 1C 2017 Greater than 3

Nozzle 3-1 per interval not to Satisfactory 10 years exceed 10 years Volumetric Once Cold Leg 1D 2017 Greater than 4

Nozzle 4-1 Satisfactory 10 years per interval not to exceed 10 years Volumetric Once Cold Leg 2A 2018 Greater than 1

Nozzle 1-1 Satisfactory 10 years per interval not to exceed 10 years Volumetric Once Cold Leg 2B 2018 Greater than 2

Nozzle 2-1 Satisfactory per interval not to 10 years exceed 1O years 2

Volumetric Once Cold Leg 2C 2018 Greater than 3

Nozzle 3-1 Satisfactory 10 years per interval not to exceed 10 years Volumetric Once Cold Leg 2D 2018 Greater than 4

Nozzle 4-1 Satisfactory 10 years per interval not to exceed 10 years Note 1: The inspection frequency as determined by ASME Code Section XI, Appendix L analysis is more than 10 years. In accordance to the requirements of Appendix L Table L-3420-1, the safety injection nozzle welds will be examined once per 1O years, at the frequency of the McGuire Nuclear Station lnservice Inspection Interval.

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