SBK-L-13173, Relief Request RA-13-001, Revision 1, Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(ii)

Relief Request RA-13-001, Revision 1, Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(ii)

ML13252A230
Person / Time
Site:	Seabrook
Issue date:	09/04/2013
From:	Ossing M NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-13173
Download: ML13252A230 (42)

Text

NEXTera ENERGYARO September 4, 2013 10 CFR 50.55a Docket No. 5 0-443 SBK-L-13173 U.S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20582 Seabrook Station Relief Request RA-13-001, Revision 1 Proposed Alternative in Accordance with 10 CFR 50.55a (a)(3)(ii)

References:

1. NextEra Energy Seabrook conference call with NRC requesting relief to perform a temporary, non-ASME Code repair to Seabrook Unit 1 Service Water System, August 30, 2013.

2. NextEra Energy Seabrook conference call with NRC providing responses to NRC questions regarding a temporary, non-ASME Code repair to Seabrook Unit 1 Service Water System, August 30, 2013.

3. NRC conference call with NextEra Energy Seabrook granting relief to perform a temporary, non-ASME Code repair to Seabrook Unit 1 Service Water System, August 31, 2013.

Pursuant to 10 CFR 50.55a(a)(3)(ii) NextEra Energy Seabrook, LLC (NextEra Energy Seabrook) requested relief to perform a temporary, non-ASME code repair to the Seabrook Station Unit 1 Service Water (SW) system. The circumstances regarding this request were discussed with the NRC staff in conference calls on August 30, 2013 (References 1 and 2). The NRC granted relief to perform the requested repair in a conference call on August 31, 2013 (Reference 3). Justification for the temporary repair of the Seabrook Unit 1 SW piping is provided in the attachment to this letter, and also includes the responses to the NRC questions regarding the issue.

NextEra Energy Seabrook, LLC, P.O. Box 300, Lafayette Road, Seabrook, NH 03874

United States Nuclear Regulatory Commission SBK-L-13 173/Page 2 Seabrook Station is in the third 10-year inservice inspection interval which ends August 18, 2020.

This request is similar to the relief granted to Southern Nuclear Operating Company, Inc.,

for the Edwin I. Hatch Nuclear Plant, Unit 1 (ML12058A413) and Shearon Harris Nuclear Power Plant, Unit 1 (ML110601120).

There are no commitments being made in this submittal.

If you have any questions regarding this submittal, please contact Mr. Michael Ossing, Licensing Manager, at (603) 773-7512.

Sincerely, NextEra Energy Seabrook, LLC Lensing Manyer

Attachment:

Request RA-13-001, Revision 1, Proposed Alternative in accordance with 10 CFR 50.55a (a)(3)(ii) cc:

W. M. Dean, NRC Region I Administrator J. G. Lamb, NRC Project Manager P. C. Cataldo, NRC Senior Resident Inspector

Attachment to SBK-L-13173 Request RA-13-001, Revision I Proposed Alternative in accordance with 10 CFR 50.55a (a)(3)(ii)

SEABROOK STATION UNIT 1 10 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)

1. ASME Code Components Affected The affected piping is the "B" Train 24-inch diameter service water supply pipe, line number SW-I1802-004-153-24", which supplies cooling water to the Primary Component Cooling Water (PCCW) Heat Exchanger CC-E-17-B for the purpose of removing heat from systems and components during normal plant operations and emergency plant evolutions. The Code component associated with this request is a Class 3 piping component in the Service Water (SW) system in which a flaw has been detected. There is one area affected by a localized flaw.

1.1 System Details:

ASME Code Class:

Class 3 System:

Service Water System Category:

Moderate Energy Piping 1.2 Component Descriptions:

The component in question is 24-inch Nominal Pipe Size (NPS) carbon steel piping with a nominal wall thickness of 0.375-inch. The application of this alternative is to perform a temporary, non-Code repair to the SW piping. This non-Code repair will consist of the addition of a 6-inch nominal diameter weldolet, weld-neck flange, and blind flange over the identified localized flawed area. The general configuration for the repair is shown in Figure 1.

2. Applicable Code Edition and Addenda

Seabrook Station is currently in the third 10-year Inservice Inspection (ISI) interval.

The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (Code) of record for the current 10-year ISI interval isSection XI, 2004 Edition, with no Addenda (Reference 1) for the Repair/Replacement Program.

3. Applicable Code Requirement

The applicable Code Sections for which the relief is requested from is ASME Code Section XI, 2004 Edition, with no Addenda, Section IWA-4412.

IWA-4412 states: "Defect removal shall be accomplished in accordance with the requirements of IWA-4420."

The identified defect will not be removed during operation of the "B" Train of Service Water because doing so would result in a significant leak rate through a larger area resulting from the removal of degraded pipe wall. Therefore relief is being requested to perform a temporary non-Code repair.

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SEABROOK STATION UNIT 110 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)

4. Reason for the Request On August 7, 2013, with Seabrook Station in operation at 100% power, a through-wall leak was identified in a section of SW system piping. NextEra Energy Seabrook performed Ultrasonic Test examination to characterize the affected area and prepared an evaluation documented in Reference 2. The examination and evaluations concluded that the leakage is a result of wall-thinning due to localized corrosion on the inside of the pipe. On August 28, 2013, the leakage increased as a result of changing the operating line-up to perform a surveillance procedure. A housekeeping patch was installed to stop the leakage. Additional ultrasonic examinations show that the wall thinning area has remained constant, however, due to increased pressure as a result of the alternate piping line-up, the leakage increased.

The remaining wall thickness currently provides sufficient structural integrity to maintain operability of the SW system.

5. Hardship of Repair Section XI of the ASME Code specifies Code-acceptable repair methods for flaws that exceed Code acceptance limits for piping that is in service. A Code repair is required to restore the structural integrity of flawed ASME Code piping, independent of the operational mode of the plant when the flaw is detected. Repairs not in compliance with Section XI of the ASME Code are non-Code repairs. Seabrook Station Technical Specifications (TS) 3/4.7.4 requires that the Service Water System be operable with two trains of service water. Performing an ASME Code repair at the flaw location during power operation would require that the "B" Train of Service Water be taken out of service. While the Technical Specifications provide 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for repair, doing so would result in the loss of one train of cooling water during the repair timeframe. The isolation and draining of the "B" train of Service Water during power operation is complex and would expend a significant portion of the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed. Shutting down the plant to perform a Code repair versus using the proposed temporary non-Code repair is considered by Seabrook Station to be a hardship.

6. Burden Caused by Compliance

It is impractical to complete a Code-acceptable repair to the identified SW leak at Seabrook Station without shutting the plant down. Shutting the plant down in mid-cycle creates undue and unnecessary stress on plant systems, structures, and components.

7. Proposed Alternative and Basis for Use

Compliance with the specified requirements of the ASME Section XI Code would result in hardship without a compensating increase in the level of quality and safety.

NextEra Energy proposes a temporary, non-Code repair consisting of the encapsulation of the identified pipe wall flaw by the addition of a 6-inch NPS weldolet, weld neck flange, and blind flange as depicted on Figure 1.

Page 2 of 6

SEABROOK STATION UNIT 1 10 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii) 7.1 Flaw Sizing and Characterization On August 7, 2013 an Ultrasonic Test (UT) examination was performed at an identified through wall leak on line SW-1802-004-153-24". The area was identified by discovery of a slow (several drops per minute) leak. The examination revealed that the through wall leak at this location was the result of a single isolated flaw that appears to be related to corrosion. Encoded UT data was collected at this location and was used to evaluate the through wall leakage area. A 3-inch by 6-inch area surrounding the flaw was selected for the encoded examination. This encoded area encompassed the entire flawed area. Normal intermittent responses could not be received in an area specifically bounded by where the inside surface response was initially lost. This resulted in a conservative bounded flaw area of 2.327-inches circumferentially by 1.500-inches axially.

Wall thickness readings could not be obtained within this region. However, it was identified that there is an abrupt increase in thickness to nominal wall (0.375 inch) and above outside this region.

During the angle beam exam, the flaw could be seen in all four directions which is not typical for planar flaws. For structural evaluation purposes the flaw was considered non-planar. At the time of the August 7, 2013 examination no visible through wall hole was identified. On August 20, 2013 an increase in through wall flow was identified. A subsequent UT examination was performed. It concluded that the bounding area of 2.327-inches by 1.500-inches remained the same with no reportable thickness recorded in this area. However, a visible through wall hole estimated to be 0.250-inches in diameter was identified. In accordance with ASME Code Case N-513-3, the entire circumference of the piping at the through wall leak location was also examined with no other defects identified.

7.2 Degradation Mechanism As discussed in Section 7.1 above, based upon the Non-Destructive Examination (NDE), the localized flaw appears to be seawater corrosion related. See further discussion on this in Section 7.4.

7.3 Flaw Evaluation A flaw evaluation, in accordance with ASME Code Case N-513-3, was performed with the through wall flaw size assumed to be the bounding area of 2.327-inches by 1.500-inches. The evaluation concluded that structural integrity is maintained. This evaluation is provided in Reference 2, a copy of which is attached. In accordance with Code Case N-513-3, augmented inspections were scheduled to be performed to determine the extent of condition.

7.4 Flaw Growth Rate As previously stated in Section 7.2, the cause of the degradation is from localized corrosion. The typical corrosion rate used in Seabrook Station Service Water piping evaluations is 30 mils per year (mpy). However, the current identified wall defect resides in piping which was recently replaced during Refueling Outage 14 during April 2011, concluding that an accelerated Page 3 of 6

SEABROOK STATION UNIT 1 10 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)

(presently unknown) mechanism exists within the bounding area. The NDE identified nominal (and above) pipe wall thickness around the bounding area. Based upon this, it is assumed that while further degradation will occur within the bounding area, the surrounding area wall loss will be such that the ASME Code required minimum pipe wall thickness, calculated to be 0.105-inch in Reference 2, will not be violated during the duration of the proposed temporary non-Code repair. To provide further assurance, a 6-inch weldolet has been selected for use.

The sizing of the weldolet (6 inch nominal) was based upon the identified wall thickness of the piping and its installation position with respect to the bounded flaw size (2.327 by 1.5 inch). The weldolet will be welded to pipe wall thickness verified to be of a thickness of 0.375 inch or better. The typical corrosion rate used by Seabrook is 30 mils per year. To proactively address the corrosion potential within the bounded area, a factor of 4 is applied resulting in a rate of 120 mils per year. Although the installation duration is less than a year (next refueling outage is Spring 2014) 120 mils is used. The resulting pipe wall under the weldolet and weldment will therefore be reduced from to 0.375 -

0.120 = 0.255 inch. The ASME Section III Code requirement for minimum pipe wall is 0.105 inch, calculated in calculation C-S-1-45893. As the pipe wall with future metal loss, calculated to be 0.255 inch, exceeds the Code minimum of 0.105 inch, structural integrity of the repair will be maintained. The 6.6875 inch inside diameter of the weldolet in relationship with the major axis dimension of the bounded flaw (2.327 inch) provides sufficient metal such that further corrosion will not affect the integrity of the repair.

7.5 Repair Components The design pressure and temperature of the Service Water piping system is 150 psi and 200 degrees F. Normal operating pressure is 75 psi and Normal operating temperature is 65 degrees F maximum and 35 degrees F minimum. The repair components, weldolet, weld neck flange and blind flange design conforms to these temperature and pressure requirements. The weldolet is constructed from ASME SA material and meets the ASME Section III ND requirement for branch connections. The welding will be performed using a qualified procedure that meets the ASME Section IX requirements for an open root, full penetration weld. The branch connection will meet the ASME Section III ND requirements for fabrication. The pre-installation NDE requirements for the weldolet consists of the verification of ASME material, the verification of proper weld joint fit-up and a final Visual and Penetrant Testing exam of the final weld. The post installation NDE requirements consist of a VT-2 for leakage in accordance Section XI, IWA-5000. The acceptance criteria are in accordance with the original construction code, ASME Section III ND, requirements. The NDE examination methods performed will meet the ASME Section XI, IWA-4500 requirements.

7.6 Piping System Impact The weight of the repair components is determined as follows: 14.20 lbs (weldolet) + 27 lbs (weld neck flange with bolting) + 26 lbs (blind flange) + 10 lbs (water content) = 77.2 lbs.

The pipe supports adjacent to the defective area are:

1802-SG Vertical support (+/-) approximately three feet downstream of the defect area (providing strainer anchorage)

Page 4 of 6

SEABROOK STATION UNIT 1 10 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii) 1802-RG Lateral support (+/-) approximately 1.5 feet downstream of the defect area on the strainer bypass piping 1802-SG Vertical support (+) approximately 9.0 feet downstream of the defect area on the strainer bypass piping.

1802-SG Vertical and lateral support (+/-) approximately 19 feet upstream of the defect area.

A review of the pipe support design documentation has concluded that the existing pipe support scheme can accommodate the weight addition of 77.2 lbs.

8. Duration of Proposed Alternative

The temporary non-Code repair to the Seabrook Station SW system will remain in place until the next Refueling Outage (OR16) scheduled for Spring 2014.

9. Post Repair Monitoring As discussed in Section 7.1, nominal pipe wall exists around the bounding area of 2.327-inches by 1.500-inches. The proposed temporary non-Code repair will be installed on this nominal pipe wall. Periodic UT inspections of no more than 30 day intervals around the installed weldolet will be performed to identify wall loss propagating outside the encompassed area.

10. Precedents

1) NRC letter from N. Salgado to M. J. Ajluni of Southern Nuclear Operating Company, Inc., "Edwin I. Hatch Nuclear Plant, Unit 1, Safety Evaluation of Relief Request HNP-ISI-ALT-14, Version 2, for the Fourth 10-Year Inservice Inspection Interval, Temporary Non-Code Repair of Service Water Piping" (TAC No. ME7366)( (ML12058A413)

2) NRC letter from D. A. Broaddus to C. Burton of Shearon Harris, "Shearon Harris Nuclear Power Plant, Unit 1 - Relief Request 13R-08, Temporary Non-Code Repair of Service Water Supply System Piping" (TAC No. ME4750) (ML110601120)

11. References

1) American Society of Mechanical Engineers (ASME) Boiler & Pressure Vessel Code,Section XI, 2004 Edition, no Addenda.

2) Seabrook Station Calculation C-S-1-45893-CALC Rev. 000 "Code Case N-513-3 Pipe Wall Flaw Evaluation for: SW-1802-004-153-24" (attached).

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SEABROOK STATION UNIT 110 CFR 50.55a Relief Request RA-13-001 Revision 1.0 Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)

Figure 1: Proposed 6-inch NPS Weldolet, Weld Neck Flange, and Blind Flange 6"BLIND FLANGE 6'WN FLANGE 8"WELDOLET I-SW-1802-004 -153-24'-

24" X 0.375'-\\

FLAW FIGURE 1 Page 6 of 6

Calculation Title Page Total number of sheets 33 (including attachments)

Code Case N-513-3 Pipe Wall Flaw Evaluation for: SW-1802-004-153-24" TITLE C-S-1-45893 0

NA SW CALCULATION #

REV. #

Vendor Calc#

System Executive Summary The through-wall pipe flaw Identified and documented in AR# 01895334 has been evaluated in accordance with NRC CC N-513-3 and found to be stable. Calculated Stress Intensity Factors for all Service conditions are within the Code Case specified allowable with the applicable structural factors applied.

The ASME Code required minimum pipe wall thickness for both Design Pressure as well as mechanical loading is tm = 0.105 inch.

The N-513-3 derived minimum wall for the adjacent non-planar flaw region is 0.120 inch.

Does this calculation:

1.

Support a MJR [DCR], MNR [MMOD], an independent review method Yes EINo 0 for a DCP, or confirm test results for an installed DCP? If yes, indicate the MJR [DCR], MNR [MMOD] number and/or Test Procedure number.

2.

Support independent analysis? If yes, indicate the procedure, work Yes [@No 0 control or other reference it supports.

Supports the response to AR# 01895334

3.

Revise, supersede, or void existing calculations? If yes, indicate the Yes E1No l]

calculation number and revisions.

4.

Involve OQAT related systems, components or structures?

Yes NNo 0l

5.

Impact the licensing basis, including technical specifications, Yes LNo 0 NUHOMS HD System Technical Specifications, technical requirements, UFSAR, NUHOMS HD System Final Safety Analysis Report, procedures or licensing commitments? If yes, identify appropriate change documents.

Approvals (Signature)

Preparer H. W. Menteld2'

-7

/'O_

Date:

13 Independent Verifier S.'Das Date:

I 2 Supervisor/Manager B. E. Brown Date: f;

/--

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NADC FORM 5B Rev. 45 Page 1 of 1

CALCULATION NUMBER Sht. No]

Revision Level Preparer/Date Verifier/Date C-S-1-45893 3

0 HWMe 8/8/13 S. Das 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation CALCULATION FORMAT TOPIC Sheet Number(s)

Calculation Cover Sheet 1

Calculation Revision Control Sheet 2

Calculation Format 3

1.0 PURPOSE 4

2.0

SUMMARY

OF RESULTS 4

3.0 REFERENCES

/ DESIGN INPUTS 5

4.0 ASSUMPTIONS 5

5.0 METHOD OF ANALYSIS

6 Background

6 Method 6

6.0 BODY OF CALCULATION 7

1.0 Scope - Applicability 7

2.0 Scope - Procedure 8

3.0 Flaw Evaluation

8 Background

8 Evaluation 11

1) Determination of Flaw Acceptance Criteria, K, 11

2) Determination of Load Relations Fm, Fb, and F 12

3) Determination of actual flaw stress Intensity factor K, for 15 Circumferential Flaw

4) Determination of actual flaw stress Intensity factor K, for 20 Axial Flaw

5) CONCLUSION - Prepared Input for Operability Determination 23 4.0 ASME Code Required Minimum Wall Thickness per CC-597 24 7.0 REVIEWERS COMMENTS AND 26 RESOLUTION

-.8.0 ATTACHMENTS 26 Total Number of ATTACHMENT Sheets 7

sheets Total Number of Calculation Sheets 33 sheets (including attachment sheets)

CALCULATION NUMBER Sht. No.

C-S-1-45893 4

TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 1.0 PURPOSE A through-wall flaw has been identified in pipe line SW-1802-004-153-24". The identification of this flaw has been entered into the Seabrook Station Corrective Action Program via Action Request (AR) 01895334.

The purpose of this calculation is to perform a wall thickness flaw evaluation in accordance with the ASME Boiler and Pressure Vessel Code Case N-513-3. This evaluation will determine whether or not the identified flaw is stable and provide input into the associated system operability determination.

Furthermore this evaluation will identify recommended actions with regards to repair/replacement activities of the subject component.

The subject piping is classified as ANS Safety Class 3; Seismic Category I.

2.0

SUMMARY

OF RESULTS EXECUTIVE

SUMMARY

The through-wall pipe flaw identified and documented in AR# 01895334 has been evaluated in accordance with NRC CC N-513-3 and found to be stable. Calculated Stress Intensity Factors for all Service conditions are within the Code Case specified allowable with the applicable structural factors applied.

The ASME Code required minimum pipe wall thickness for both Design Pressure as well as mechanical loading is tm = 0.105 inch.

The N-513-3 derived minimum wall for the adjacent non-planar flaw region is 0.120 inch.

CALCULATION NUMBER Sht. No, C-S-1-45893 5

Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Dos 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation

3.0 REFERENCES

I DESIGN INPUTS

1) Action Request # 01895334

2) Code Case N-513-3 "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping,Section XI, Division 1", Cases of ASME Boiler and Pressure Vessel Code, January 26, 2009.

3) ASME Boiler and Pressure Vessel Code,Section III 1983 Edition. (2007 Edition used for material properties).

4) ASME Boiler and Pressure Vessel Code,Section XI, Appendix C, 2004 Edition

5) Regulatory Guide 1.147, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1", Revision 16, Nuclear Regulatory Commission, October 2010.

6) Y. Takahashi, "Evaluation of Leak-Before-Break Assessment of Pipes with a Circumferential Through-Wall Crack. Part 1: Stress Intensity Factor and Limit Load Solutions," International Journal of Pressure Vessels and Piping, 79, 2002.

7) Pipe Fracture Encyclopedia, US Nuclear Regulatory Commission, Volume 1, 1997.

8) Guidelines for Selection of Marine Materials, 2 nd Edition, May, 1971 Copyright © 1966, The international Nickel Company, Inc.

9) FPL Energy Seabrook Structural Engineering Standard Technical Procedure DS36460, Rev. 3, Chg.

00 "Structural Evaluation of Flow Accelerated Corrosion (FAC) in Carbon Steel Piping and Piping Wall Flaws".

10) Code Case N-597-2 ""Requirements for Analytical Evaluation of Pipe Wall Thinning,Section XI, Division 1".

11) Nuclear Fleet Procedure EN-AA-203-1001 Rev. 9, "Operability Determinations / Functionality Assessments".

12) Design Control Manual, NADC Rev. 59

13) Piping Isometric: SW-1802-09 Rev. 7

14) Design Change Isometric SK-EC156603-2001 Rev. 2

15) "Piping Design and Engineering" Fourth Edition, Revised 1973 from ITT Grinnell Corporation.

16) Piping Stress Analysis of Record C-S-1-45718-CALC Rev. 7

17) Calculation 4.4.17.04F-CALC Rev. 6 4.0 ASSUMPTIONS None

CALCULATION NUMBER Sht. No.

C-S-1-45893 6

TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 5.0 METHOD OF ANALYSIS Hand Calculation

Background:

The subject piping is SW-1802-004-153-24", and depicted on isometric SW-1802-09. the latest design change isometric is SK-EC156603-2001.

The current analysis of record for the piping is calculation C-S-1-45718-CALC Rev. 7.

Results from ADLPIPE Output SWONER4.000 dated 07/02/2013 are used.

The ADLPIPE software model node at or adjacent to the through wall leak location is 475.

The following forces and moment loading has been extracted for use in this calculation.

NOTE: Axial Force = Fz; Torsional moment = Mz Resultant moments MR conservatively used Load Forces, (lbs.)

Moments, (ft-lbs.)

Forces, (kips)

Moments, (in-kips)

Fx Fy Fz Mx My Mz MR Deadweight 772

-374

-135 492 362 1218 1363 File 11

-0.135 16.356 OBE Inertia +

16061 5082 10799 15993 20730 11987 28796 File 31 10.799 J _

345.552 SSE Inertia +

20610 7510 16605 22570 29614 18457 41558 File 41 1

16.605 498.696 Hydraulic 382 1074 324 3623 3667 1602 5398 Transient +

0.324 64.776 File 200 Due to the nature of the hydraulic transients (pump starts/re-starts) Hydraulic Transient loads need not be combined with seismic loading Ref: C-S-1-45718-CALC Rev. 7)

Applicable stress intensification factor, i = 1.0 (Straight pipe).

Method:

Utilizing the mechanical loading shown above, the fracture toughness of the remaining pipe wall will be

-.evaluated per the criteria presented in Code Case N-513-3, to determine the likelihood of further flaw propagation due to the subjective loading. Verification of flaw stability does not negate the requirement of addressingthe potential for further degradation due to salt water intrusion.

CALCULATION NUMBER Sht. Nol C-S-1-45893 7

TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. DOS 8/8/13 6.0 BODY OF CALCULATION 1.0 Scope - Applicability:

(a) The Code Case requirements apply to ASME Section III, ANSI B31.1 and ANSI B31.7 piping classified as Class 2 or 3.

The subject piping is classified as: ASME Section III, Subsection ND The subject piping component is : straight pipe downstream to tee Piping Material is: SA 106 Grade B CAUTION NOTE: Code Case is not applicable to the following:

(1) pumps, valves, expansion joints and heat exchangers; (2) socket welds; (3) leakage through a flange joint; (4) threaded connections employing nonstructural seal welds for leakage protection.

(b) The Code Case applies to Class 2 or 3 piping whose maximum operating temperature does not exceed 200°F and whose maximum operating pressure does not exceed 275 psig.

The subject piping maximum operating temperature = 90 < 200°F The subject piping maximum operating pressure = 171 < 275 psig Reference Source for temperature / pressure conditions: Calculation 4.4.17.04F-CALC Rev. 6, Sht. U-3 (c) Flaw Evaluation criteria are permitted for pipe and tube. It cannot be used for adjoining fittings and flanges as calculations are based upon round pipe. However the criteria is applicable to that portion of the fitting where it transitions from pipe up to a distance of (Rot)1/ 2 from the weld centerline.

Is the flaw location adjacent to a fitting / flange weld ?

Yes, but located on the straight pipe; (R.1t) 1/ 2 criteria is not applicable.

CALCULATION NUMBER C-S-1-45893 Sht. No.

8 Revision Level Preparer/Date Verifier/Date 0

HWMe 818113 S. Das 818113 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation 2.0 Scope - Procedure:

(a) The flaw geometry shall be characterized by volumetric inspection methods or by physical measurement. The full pipe circumference at the flaw location shall be inspected to characterize the length and depth of all flaws in the pipe section.

The subject flaw has been characterized by: UT exam ES1807.012 Form A: Ultrasonic Thickness Examination Report attached. See Attachment A (b) Flaw Classification: Planar or Nonplanar Ref: a) See N-513-3 Fig. 1 -Through wall flaw geometry-all through wall flaws are planar b) See N-513-3 Fig. 3 - Nonplanar Flaw due to Wall Thinning Based upon the description in AR# 1895334, AR photographs and the examination data documented in Attachment A, the flaw is classified is classified as non-planar.

(c) Are multiple flaws present? (circle, as applicable)

No If the answer is yes, the interaction and combined area of loss of flaws in a given pipe section shall be accounted for in the flaw evaluation. In accordance with Section IWA-3300 of Section XI, the adjacent flaws shall be bounded by a single rectangular or circumferential planar area.

(d) A flaw evaluation shall be performed to determine the conditions for flaw acceptance.

Section 3.0 provides the accepted methods for conducting the required analysis.

3.0 Flaw Evaluation:

Background

Typically flaw evaluations are prepared for identified through wall flaws in ferritic piping.

Code Case N-513-3 provides criteria for the evaluation of nonplanar flaws (Section 3.2) and planar flaws in austenitic piping (Section 3.1(b)).

What follows is a review of the Code Case N-513-3 sections.

3.1(a) For planar flaws, the flaw shall be bounded by a rectangular or circumferential planar area in accordance with the methods described in ASME Section XI, Appendix C. Note that the flaw to be

.addressed should in most cases be a surface flaw on the interior diameter of the piping. Based upon Article C-2400 the flaw has to be characterized as axial, circumferential or a combination of both. The minimum wall thickness should first be determined as follows: (CC N-513-3 Eq. 4) pD, 2(S+0.4p)

CALCULATION NUMBER Sht. No]

Revision Level Preparer/Date Verifier/Date C-S-1-45893 9

0 HWMe 8/8/13 S. Das 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation P = maximum operating pressure at flaw location = 171 psi Ref. Source = 4.4.17.04F-CALC Rev. 6 Sht. U-3 D0 = Piping outside diameter = 24 inches S = pipe material allowable stress at operating temperature (171)(24) 01195=0.120inch 2(17100+

0.4(171))

=

Utilizing the derived value of tm envelope those area(s) mapped on the E51807.012 Form A: Ultrasonic Thickness Examination Report (Attachment A). Determine the applicable general flaw length dimension, L, in both the axial and circumferential directions.

As discussed in the UT report the flaw size is conservatively bounded by 2.327 inches circumferentially by 1.50 inches axially due to the absence of normal intermittent responses. The area is bounded by-good wall with thickness ranges of 0.592 to 0.896 inch for the tee and 0.388 to 0.420 inch for the pipe.

Within the bounded area the remaining wall cannot be measured and is assumed to be 0.00 inch thick.

The fact that wall does physically exists the flaw is considered to be non-planar NOTE: It is very rare that identified flaws in SW system piping are purely axial or circumferential in nature.

The identified flaw is characterized as: (check off as appropriate)

[

AXIAL L0xi0, = 1.50 inches

[

CIRCUMFERENTIAL Ldrc= 2.327 inches If multiple planar flaws have been identified, discontinuous indications shall be considered as singular flaws if the distance between adjacent flaws is equal to or less than the dimension S, where S is determined in accordance with Section XI Fig. IWA-3330-1.

3.1(b) For planar flaws in austenitic piping.........

Not applicable to this evaluation.

3.1(c) For planar flaws in ferritic piping...... this section is addressed below.

3.2 For nonplanar flaws........

Not applicable to this evaluation, except as may be noted above.

.3.2(c) When there is through-wall penetration along a portion of the thinned wall, as illustrated in N-513-3 Fig. 5, the flaw may be evaluated by the branch reinforcement method. This approach is practical when highly localized pinhole leaks are identified, but not utilized here.

3.2(d) The identified flaw may be evaluated as two independent planar through -wall flaws -one oriented in the axial direction and the other oriented in the circumferential direction. The through-wall lengths for each flaw are the lengths Laxaia and Ldrc where the local wall thickness is equal to tm as projected along the

CALCULATION NUMBER Sht. No C-S-1-45893 10 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Dos 8/8/13 axial and circumferential planes. Conservatively in considering a flaw as both axial and circumferential, the larger determined length can be utilized. Hence the flaw is considered as circular with a diameter equal to L. Note that the flow area of the flaw, or the total of the flow areas of multiple flaws that are combined into a single flaw for the purpose of evaluation, shall not exceed the lesser of the flow area of the pipe or 20 in. 2.

Lrc = 2.327 inches will be used for the circumferential direction Laxiai = 1.5 inches will be used for the axial direction Check the flow area of the mathematical representation of the flaw:

Area = L.x1, Lc*

= (1.5)(2.327)

= 3.491 *! lesser of 20in2 or Pipe flow area 3.3 In performing a flaw growth analysis, the procedures in C-3000 may be used as guidance. Relevant growth rate mechanisms shall be considered. Article C-3000 addresses flaw growth attributed to fatigue due to cyclic loading and SCC growth. For the SW system piping, the primary growth mechanism is the rate of wall loss due to exposure to seawater. Per Reference 8, the typical corrosion rate of carbon steel immersed in quiet seawater is 15 mils per year.

3.4 For non-ferrous materials, flaws may be evaluated............

Not applicable to this evaluation.

3.1(c) For planar flaws in ferritic piping, the evaluation procedure of Appendix C shall be used. Per Article C-1000, Section C-1200(f) the screening procedure described in C-4000 should be used to determine the failure mechanism for the material and temperature for the identified flaw. However per Article C-4000, Section C-4222 the criteria for Classes 2 and 3 ferritic piping are in the course of preparation. The analyst shall establish the failure mode relevant for the flawed pipe under evaluation.

Considering the larger SC (> 1.8) criteria (see Fig. C-4220-1) and the fact that NRC Generic Letter 90-05 recommended a LEFM approach for evaluating through-wall flaws in Class 3 piping, the Article C-7000 LEFM criteria is used. When through-wall flaws are evaluated in accordance with C-7300 or C-7400, the formulas for evaluation given in C-4300 may be used, but with values for Fm, Fb, and F applicable to through-wall flaws. Relations for Fm, Fb, and Fthat take into account flaw shape and pipe geometry (R/t ratio) shall be used. Appendix I to CC N-513-3 provides equations for Fmo, Fb, and Ffor a selected range of Rit. The Fm and Fb equations provided in CC N-513-3 are accurate in the range of R/t of 5 to

20. It is noted that alternative solutions for Fm and Fb may be used when the R/t ratio is greater than

20. The Takahashi relations presented in Reference 6 are applicable in the R/t range of 1.5 to 80.5 and will be used in this calculation.

CALCULATION NUMBER Sht. No C-S-1-45893 11 Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Dos 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Evaluation

1) Determination of Flaw acceptance criteria. The stability of an identified through-wall flaw is considered acceptable provided the derived stress intensity factor, KI, is less than the critical fracture toughness for the material, which is based upon the measure of toughness of the material.

K (J, El 0 0 J" For through-wall flaws, meeting the above criteria ensures the acceptability of the pipe for temporary service. Margin is provided by the use of the structural factors dictated by CC N-513-3.

Article C-8000, Section C-8321 addresses toughness properties for ferritic steel base metals subject to circumferentially and axial oriented flaws, with a minimum upper shelf temperature value given in the absence of specific data.

For this calculation a minimum Jk value for SA-106 Grade B carbon steel base metal is obtained from Reference 7. Table BI in Reference 7 provides a summary of all low temperature fracture testing conducted with SA-106 Grade B material in the database. The lowest value J1, = 293 lbs. / in. has been conservatively selected for use in this CC N-513-3 evaluation.

Per C-1300, E' = E/(1 - v2)

E = Young's Modulus at maximum operating temperature = 29,392 ksi @ 90°F v = Poisson's ratio = 0.3 E' =

29392/(1-0.32)

= 32299 ksi K,

=

(293 (322 99 1000 7.281 ksi.

CALCULATION NUMBER Sht. No]

C-S-1-45893 12j Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation

2) Determination of Load Relations Fm,,

Fb, and F for through-wall flaws. For through-wall flaws, the crack depth (a) will be replaced with the half crack length (c) in the stress intensity factor equations used (per CC N-513-3 Appendix I, section I-1).

Circumferential Flaw Load Relations - From Reference 6 (NOTE: Ft =Fm)

Geometrical factor for axial load:

B,

= [4

+{ CQ9.)1 + DC0

+ E,(0]

B,

-1.040 - 3.183 1(4) - 4.83()Y - 2.369(4ýY C,

16.71 + 23.10(,)+ 50.82(Y)2 + 18.02(ý)

D, = - 25.85 - 12.05(4) - 87.24(ýY - 30.39(Y)3 E, =

24.70 - 54.18(4) +18.09(Y)2 + 6.745(Y)3 l og( R Geometrical factor for bending moment:

Fb= (I+/-

[ Ab ++/-Bb(")D+CbQP-D + DbQ(+/-b"~

Ab

=

0.65133- 0.5774(g)- 0.3427()

2 - 0.0681(4)

Bb

= "1.879 + 4.795(ý) + 2.343(ý4Y - 0.6197(ýY Cb

= - 9.779 - 38.14(g) -6.61 1()2 + 3.972(*)3 Db

= 34.56 + 129.9() + 50.55()2 + 3.374(43 Eb

= -30.82-147.6(ý')--78.38(ý)Y

-15.54('3 l log(*-

CALCULATION NUMBER Sht. No C-S-1-45893 13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 Lc= 2.327 inches c= Lrc,2 = 1.1635inches OD = 24 inches t = 0.375inches (Note: surrounding "good" wall - not nominal) Per the UT report, outside the bounding area the thickness abruptly changes to above nominal wall; therefore nominal wall thickness is used.

R = (OD - t) / 2 = 11.8125 inches Rit = 31.5 NOTE: for R/T ratio > 20, the Equations for Ft and Fb become increasing conservative.

0 = c/R = 1.1635 / 11.8125 = 0.0985 0 / T = 0.0313 l=

oog(t

= log(- 18*-.35

= -1.498 A

B, C,

- 1

= -1.040-3.1831(- 1.498)- 4.83(- 1.498Y -2.369(- 1.498)3

=

= 16.71+23.10(-1.498)+ 50.82(-1.498)2 +18.02(-1.498)2

=

= -25.85 -12.05(- 1.498)-87.24(- 1.498)2 - 30.39(-1.498)2

=

24.70-54.18(-1.498)+18.09(-1.498)2 +6.745(-1.498)3

=

0.853 35.572

-101.41 123.78 F, =

[1+ 0.853(0.0313)+35.572(0.0313)2 -101.41(0.0313)3 +123.78(0.0313)4]

= 1.059 Ab Bb Cb Db Eb 0.65133.- 0.5774(- 1.498) - 0.3427(- 1.498)2 - 0.0681(- 1.498)Y 1.879 + 4.795(-1.498)+ 2.343(-1.498)2 -0.6197(-1.498)2

=

= -9.779-38.14(-1.498)-6.611(-1.498)2

+ 3.972(-1.498)3

=

34.56 + 129.9(-1.498)+ 50.55(-1.498)2 + 3.374(-1.498)2

=

-30.82-147.6(-1.498)- 78.38(-1.498)2 - 15.54(-1.498)2

=

=

0.976 2.037 19.168

- 57.938 66.638 Fb 0+

!.175 )

[0.976+2.037(0.0313)+19.168(0.0313)2-57.938(0.0313)2 +66.638(0.0313)4]

1.074 Fb

1+2(I1.8125)J

CALCULATION NUMBER Sht. No]

Revision Level Preparer/Date Verifier/Date C-S-1-45893 14 0

HWMe 8/8/13 S. Dos 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Axial Flaw Load Relation F

= 1 + 0.0724492A + 0.64856X2 - 0.2327,V + 0.03815424 - 0.0023487 X where c

= half crack length A

= c/(Rt)X Laxat= 1.5 inches c = LaxaIl/2 = 0.750 inches OD = 24 inches t = 0.375inches (Note: surrounding "good" wall - not nominal) Per the UT report, outside the bounding area the thickness abruptly changes to above nominal wall; therefore nominal wall thickness is used.

R = (OD - t) / 2 = 11.8125 inches A = cl (Rt)'1 2 = 0.750 / (11.8125 x 0.375)1/2 = 0.356 F

1+0.072449(0.356)+ 0.64856(0.356)2 -0.2327(0.356)3 + 0.038154(0.356)4 -0.0023487(0.356)'

= 1.098

CALCULATION NUMBER Sht. No.

C-S-1-45893 15 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13

3) Determination of actual flaw stress intensity factor K, for Circumferential Flaws (Ref. C-7300 / C-4311)

K,

= KI, + KA + Kir where K.

= (SFn)(P 2 TrR at)a) (F.,)

K A =

(

, M /

'+ a,( z a) " (F,)

Kir

= K 1 from residual stresses at the flaw location where S F, and S Fb are structural factors from C -2621 - see below a

is flaw depth which for through - wall flaws is equal to c the half crack length P

is the total axial load on pipe including pressure, kips R,,tFr,F, previously defined/derived M

is applied moment on the pipe, in -kips a,

secondary bending stress (unintensified), thermal expansion The Structural Factors for Circumferential Flaws per C-2621 are as follows:

Service Level Membrane Stress, Bending Stress, SF, SFb A

2.7 2.3 B

2.4 2.0 C

1.8 1.6 D

1.3 1.4 General Notes:

1) Unless there is evidence of a base metal repair or other wall repair history and in consideration of low operating temperature, KI, is assumed to be 0.00.

2) Kim and Kib will be calculated for Service Levels A (Normal), B (Upset), C (Emergency) and D (Faulted).

CALCULATION NUMBER Sht. No]

C-S-1-45893 16 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation P and M determination for Service Levels A, B, C & D

~pre

=

(

.p ra,

)AFLONV 1000 where A4FLow=

Pnormal

=

PDW + Pressure P.pset

= PDW + Pp..e.. +

2OF +

p2S

+ p Pemergency DW + Pprsr + PT Pfa-Ited PD W pressure TPR 1D+

1 Mnooa

=

MIDW e=

M

+ MBES

+ M Meme..rgey

=

MDW + MTR Mfilted MDW + MsE + M D + M Normal Loads:

Ppressure

=

(mx.operati g pre..)

AFLOW1000

=

(171)(424.

Pn,,oma

=

Pow +Ppre.ure

(0.135)+(72.607)

72.742, Morai

=

MDw

=

16.356in-kips Upset Loads:

Pset=

PDW+

+Ppressure +

0BF1+

SAD + P1R

=(0.135)+ (72.607)+ +/-(10.799)+ (0)2 + (o)=83.541 kips MUpse, = MDW +,Mg/UEJ, + M02BE,* + MTR

=(16.356)+ 4(345.552) +(0)2 +(0)= 361.908 in-kips Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Dos 8/8/13 (OD - 2(t)J

=24

-20.375))

424.6 000

=

72.607kips kips

CALCULATION NUMBER Sht. No.

Revision Level Preparer/Date Verifier/Date C-S-1-45893 17 0

HWMe 8/8/13 S. Dos 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Emergency Loads:

PeMergency = PDW+Ppressure + PTR

=(0.135)+ (72.607)+ (0.324)= 73.066 kips Memergency = MDW + MTR

=(16.356) +(64.776)=81.132 in-kips Faulted Loads:

Pfaulie

= DW + pp..sw' 1 SEI +~S"SESD +

T

=(0.135)+ (72.607)+ ý(16.605)2 +(oY + (0)= 89.347 kips Mfaulted = MDW +

MM.

+ MSEn

+

=(16.356) + *(498.696)2 +(0)2 +(0)= 515.052 in-kips Determination of actual flaw stress intensity factor K, for Circumferential Flaws K,

=

K1++Kb+KIr where KI.=

(SFn,)(P 2 7.Rmt))(ra)°5 (Fm)

Kib

[(SFb(M tJ+o.,J(Yrayo

)

Kir

=

0.0 The stress intensity attributed to residual stresses (Kir) is 0.0 based upon the fact that the piping at the leak location was replaced in April 2011 under EC# 156603. At the time of the replacement there was no evidence of a base metal repair nor was one applied. Furthermore this piping is subject to low operating temperature.

CALCULATION NUMBER Sht. No]

Rev C-S-1-45893 18 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Normal K, Determination (All equation terms previously derived)

K, = K* + Kib ision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 I K,

=

(m)flna(2J,,))ao(F)+

[(S~(MnormaI,ýj+ o~r"] Taf-5(Fb K,

= (2.7)((72.742)*2*Y(1.8125)(0.

3 7 5 )))(7r(.1635))" (1.059)

+

[(2.3{(1 6.356)/(i.15)

) + (0.0) (; (i. 163 5))0.5(i.074)

K,

= 14.287+0.470=14.757ksi in.

Upset 1K Determination (All equation terms previously derived)

K, = K* + Kib K,

= (SF,(;)(Pse 2zRtKJ(lra) (F)+

[(SFb(M P 2RtR +a.,],(ra)0"(Fb)

K,

=

(2"4)((83".541)(2,-r(1 1.8125)(0.375)))(x(1.1635))0' (1.059)

+

[(2. (361.908)/

+)

(

(.

1635))o (1.074)

=

K,

= 14.585+9.041=23.626ksifin

CALCULATION NUMBER Sht. No Revision Level Preparer/Date C-S-1-45893 19 0

HWMe 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Emergency ýK Determination (All equation terms previously derived)

K,

= KI. + K~b K,

= (S Fm )tje8nY R,)(2)

(F.) +

(S Fb(ýM`9n JaelA a 0 Y(

YP (2;r R. t))

.SI M "

/

t ) + e] (Yra°'+

Verifier/Date S. Dos 8/8/13 K,

= (1.8)((73.06*6

.*)/,/

)(o.37S)))(f(1.1635)f (1.059)

+

[(1.6 (81.132) 1

+l(0. 1(,r(1.1635)o(1.074),

K,

= 9.567+1.621=11.188ksifn.

Faulted t, Determination (All equation terms previously derived)

K,

= K* + Kjb K,

=

(SFJ('pfauf /(2,,m t)Jr)(i,)a

+ [(SFb(ýMfaIedlýJ? ) + aý](;ray' (Fb)

K,

= (1.3)((937 (2 ;r(11. 8125)(0.3 75))) (;r (1.

.163 5)YO.5 (1.059)

+

L Q

4{(515.052)/, i 82) o3 5I (0.0) (Ti.1 635))05 (1.074)-

K,

= 8.449+9.007=17.456ksiVin.

Summary of calculated K, values for the identified Circumferential through-wall flaw Nbrmal Upset Emergency Faulted K, ksi Fi.

14.757 23.626 11.188 17.456

CALCULATION NUMBER Sht. No, C-S-1-45893 20 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13

4) Determination of actual flaw stress intensity factor K, for Axial Flaws (Ref. C-7400 / C-4312)"

K,

=

KI

+ Ki, where Kj,=

(SFm)(jpRm/t)(;r a/Q)°* (F)

Kl,.

= K, from residual stresses at the flaw location where F

is the structural factor from C -2622-see below a is flaw depth which for through -wall flaws is equal to c the half crack length p is the maximum operating pressure, ksi SFm,&R,t previously defined/derived Q = I + 4.593 (ally"65 = 1.0 (set to unity per CC N -513 -3 Appendix I for through -wall flaws)

The Structural Factor for Axial Flaws per C-2622 are as follows:

Service Level Membrane Stress, SFm A

2.7 B

2.4 C

1.8 D

1.3 General Notes:

3) Unless there is evidence of a base metal repair or other wall repair history and in consideration of low operating temperature, K1, is assumed to be 0.00.

4) Kim will be calculated for Service Levels A (Normal), B (Upset), C (Emergency) and D (Faulted).

Determination of actual flaw stress intensity factor K, for Axial Flaws

CALCULATION NUMBER Sht. Nol C-S-1-45893 21 Revison0I Level Preparer/Date Verifier/Date HWMe 8/8/13 S. Das 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Determination of actual flaw stress intensity factor K, for Axial Flaws K,

= Ki + K, where K,

= (SFmXpJm/t)( Ta/1.00 5 (F)

Ki, =

0.0 The stress intensity attributed to residual stresses (Kir) is 0.0 based upon the fact that the piping at the leak location was replaced in April 2011 under EC# 156603. At the time of the replacement there was no evidence of a base metal repair nor was one applied. Furthermore this piping is subject to low operating temperature Normal Kj Determination (All equation terms previously derived)

K,

= K*

= (SFm)(pRm/t)(Yra/1.O)Y-(F)

= (2.7)((0.171)(11.8125)/(0.375))(,r (0.750))°5 (1.098)

K,

=

24.512ksi i*.

Upset K Determination (All equation terms previously derived)

K,

= KI.

= (SFm)(pRm/t)(Ava/1.O)°" (F)

= (2.4)((0.171)(11.8125)/(0.375))(7r(O.750))'5 (1.098)

K,

= 21.788ksi in.

.Emergency K, Determination (All equation terms previously derived)

K1

=

K1

= (SFm)(pR1/t)(Yra/1.O)Y5 (F)

= (1.8)((0.171)(11.8125)/(0.375))(7r(0.750))'5 (1.098)

K,

=

16.341 ksi1fi-

F Ii CALCULATION NUMBER Sht. No Revi C-S-1-45893 22 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Faulted K, Determination (All equation terms previously derived)

K,

=

K.

= (SFm)(pR /t)(;ra/1.O)°(F) sion Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Dos 8/8/13

= (1.3) ((0.171)(11.8125)/(0.375))(nr (O.750))'5 (1.098)

K, = 11.802ksifin.

Summary of calculated K1 values for the identified Axial through-wall flaw Normal Upset Emergency Faulted K, ksi i.

24.512 21.788 16.341 11.802

CALCULATION NUMBER Sht. No.

C-S-1-45893 23 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13

5) CONCLUSION - Prepared input for use in the Operability Determination FLAW STABILITY CHECK Flaw Type Service Load Stress Intensity Factor Allowable / Calculated Calculated Allowable Circumferential Normal 14.757 97.281 6.59 Upset 23.626 97.281 4.12 Emergency 11.188 97.281 8.70 Faulted 17.456 97.281 5.57 Axial Normal 24.512 97.281 3.97 Upset 21.788 97.281 4.46 Emergency 16.341 97.281 5.95 Faulted 11.802 97.281 8.24 The calculated Stress Intensity Factors include the required structural factors prescribed by Code Case N-513-3 and ASME Section XI, Division 1 Article C-2620. The acceptable calculated stress intensity factors ensures the acceptability of the pipe for temporary service.

The Structural Factors for Circumferential Flaws per C-2621 are as follows:

'Service Level Membrane Stress, Bending Stress,-

SFm SFb A

2.7 2.3 B

2.4 2.0 C

1.8 1.6 D

1.3 1.4 The Structural Factor for Axial Flaws per C-2622 are as follows:

Service Level Membrane Stress, SFm A

2.7 B

2.4 C

1.8 D

1.3 A review of the Flaw UT data identified an adjacent minimum remaining pipe wall (tp) of 0.388 inch. This is a non-planar flaw and per CC N-513-3 must be greater than the N-513-3 derived minimum wall.

t,

=

(0.388)->tm.

=

(0.120)(calculatedon sht.9)

CALCULATION NUMBER Sht. No, C-S-1-45893 24 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation 4.0 ASME Code Required Minimum Wall Thickness per CC-597 Determine minimum wall required for Design Pressure Revision Level Preparer/Date Verifier/Date 0

HWMe 818113 S. Das 818113

_i PD.

S2(S+yP)

P = Design operating pressure at flaw location = 150 psi Ref. Source = Calculation 4.4.17.04F-CALC Rev. 6, Sht. U-3 D, = Piping outside diameter = 24 inches S = pipe material allowable stress at Design Temperature = 17100 psi @2000F y = 0.4, except where D, < 6 (tmi) (Note: use 0.4 then verify that this value is acceptable)

(150)(24) 0.105 inch 2(17100+

0.4(150))

=

Do

=

24 6(0.105) = 0.630 use of 0.4 is acceptable Determine minimum wall required for mechanical loading Piping Stress Evaluation (Simplified Analysis Approach)

The effect on piping stresses at the reduced wall location must be evaluated with consideration given to changes in the pipe metal area, pipe inside area, section modulus and stress intensification factor.

EQ.8=PDo/4tpred + 0.75i[(Mb+PAo8)/Zmin)V]

1.143S with Mb based upon deadweight loads only.

EQ.9=PD0 /4tpred + 0.75i[(Mb+PAoa)/Zmin)]< 1.143xl.2S=1.372S with Mb based upon deadweight, OBE seismic and transient loads, as applicable.

For the evaluation the derived minimum wall thickness for pressure is used for tpred.

..Ao = total cross-sectional area of pipe based on nominal outside diameter, 7R D 2 / 4 =452.4 in.2 8 = nominal distance between the center of the pipe and the neutral axis of the thinned piping section

=tnom-tpred = 0.375-0.105 =0.270 in.

Zmln=lmin/Rmax where Rmax (Do/2) + 8 = 12.270 in.

where I min 0.0491 [ D,4 - (Do - 2 tpred )4 ] = 562.72 in. 4 Zmin = 45.861 in. 3

CALCULATION NUMBER Sht. No, Revision Level Preparer/Date Verifier/Date C-S-1-45893 25 0

HWMe 8/8/13 S. Dos 8/8/13 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation The moment loading terms were extracted previously and are displayed on Sht. 6 (Note: MR conservatively used)

For Deadweight Mb = (12) 1363

= 16356 in-lbs.

For Total Mb = Deadweight + SRSS (OBEI & OBEA) + TR = (12) 30159

= 361908 in.-lbs.

Intensification factor = 1.0; Considering the wall thinning, the factor is re-calculated as follows:

Not required due to component being straight pipe.

EQ.8=PDo/4tpred + 0.75 i[(Mb+PAo8)/Zmmn )]< 1.143S EQ. 8 = 8571 + 756 =

9327 < 1.143 ( 17100 ) =19545 psi EQ.9=PDo/4tpred + 0.75 i[(Mb+PAo8)/Zmjn)]< 1.143x1.2S=1.372S EQ.9= 8571+ 8291 =

16862 < 1.372(17100 ) =23461psi

] Simplified stress evaluation is acceptable with calculated stresses within Code allowable. Check for cyclic operation.

-- Simplified stress evaluation is not acceptable. Detailed review performed in calculation Evaluation for Cyclic Operation IS t pred = 0.105 > 0.75 t norm = 0.281 ?

DYES E NO Is N (Equivalent Full Temperature Cycles) at time of next inspection < 150 ? H YES E NO If the response to both questions is YES, piping stress equations that include thermal expansion and anchor movements stresses need not be evaluated. If not, continue below.

The thermal expansion and anchor movement stress at the inspection location from the referenced analysis of record is not applicable (cold system; no anchor movement).

The Stress Range Reduction Factor (f) used in analysis is 1.0 Is N (Equivalent Full Temperature Cycles) < 650 ? E YES DI NO If the response is YES - no further cyclic evaluation is required; component is acceptable.

CALCULATION NUMBER Sht. No C-S-1-45893 26 TITLE: Code Case N-513-3 Pipe Wall Flaw Evaluation Revision Level Preparer/Date Verifier/Date 0

HWMe 8/8/13 S. Das 8/8/13 7.0 REVIEWERS COMMENTS AND RESOLUTIONS Line by line check performed.

Any and all reviewer comments, corrections, and changes have been reviewed by the Cognizant Design Engineer and have, with the mutual consent of the reviewer, been incorporated.

8.0 ATTACHMENTS Check as applicable; identify Attachment letter and number of sheets:

ED Pending Engineering Change Review - Attachment Number of sheets

-- ADLPIPE / CARS output.

Input file Output file Run date Attachment Number of sheets Input files stored on EMAGDK#

I*

Other: (list along with Attachment letter and number of sheets per attachment).

Identified Flaw UT Report Attachment A Number of Sheets: 7 Total number of Attachment sheets: 7.

Form A: Ultrasonic Thickness Examination Report COMPONENT ID: [

DRAW*iNG NO.:

k-ri-L4 WORK DOCUMENT:

SYSTEM:

REV.:

.BLDG.:

CLASS:

JOINT #:

YL sziuL, P'k-&

ROOM:

SLbr ELEV.:

C--- I INSTRUMENT DATA INSTRUMENT:

MFG/MODEL:

'law Detector 0 Thickness Gaug COMP SURFACE TEMP >1250 1P

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0y 0 YES FLS No.:

9/22 CAL. DUE DATE:

THICKNESS: O.*

01 TRANSDUCER CAL BLOCK FLS NO.:

TIME MFG.:

mc-VO.1*

MATLCS_

CAL. DUE:

CHECKED SER #:

t INrrIAL:

S.IZ)E O.1,t

-P s

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MHZ CALIBRATION INTERIM:

COIJPLANT CHECK INTERM MPG.:

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TYPE#:

Oum,ýL FINAL:

6.*bu O,.,

BATCH#:

COMMENTS SKETCH (include obstructions, components, extensions, etc.)

,>6TTACHED COATED SURFACE Maximum Coating Thickness M,.

Minimum Wall Thickness M, NON-COATED SURFACE Maximum Thickness I Minimum Wall Thickness ACCEPTABLE 0] REJECT REO.

EXAMINER: (signature)

EXAMINER: (print)

LVL DATE REVIEWER: (print)

LVL DATE ENGINEERING EVALUATION 0 N/A

'0 ATTACHED 0 SEE BELOW EVALUATION COMMENTS:

0 ACCEPT RESPONSIBLE ENGINEER DATE:

(To be completed if required above)

ARN:

0NS334 ORIGINATOR:

wives DATE:

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ENEF SEABROOK UT Thickness Examination at Through Wall Leak Upstream of SW-V-65 (817113, WO-40260904-02, AR-01 895334)

Discussion On August 7, 2013 a through wall leak was detected on line SW-802-004-153-24" upstream of SW-V-

65. The leak is adjacent to the Tee-to-Pipe weld near SW-V-104. In accordance with WO-40260904-02 the area surrounding the through wall leak was UT examined. Additionally, in accordance with AMSE Code Case N-513 the entire circumference at the through wall leak was also examined. Approximately six inches upstream and downstream of the through wall leak area was examined (see below). The exam was performed to determine magnitude and extent of all flaws the pipe section.

Examination Technique The examination was performed using a 12 element, 5MHz array with a 7.2 mm active aperture. The focal laws generated 61 Longitudinal Wave (L-Wave) examination angles from -30° to 300.

In addition to the L-Wave exam a supplemental Shear Wave (S-Wave) angle beam exam was performed. This exam was performed in order to eliminate the possibility that a non-corrosion type degradation mechanism, specifically planar flaws or cracking, was present. This technique used the same array but generated only 41 angles that ranged from 300 to 700.

Examination Results The examination revealed that the through wall leak at this location is the result of a single isolated flaw that appears to be related to corrosion. The thickness ranges of the examination areas away from the flawed area at the through wall leak are within the nominal with no corrosion present. The thickness ranges outside the leak region were 0.592"-0.896" for the Tee and 0.388"-0.420" on the piping.

WO-40260904-02, UT Report Summary IT

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,ii"O SEABROOK Encoded UT data was collected at this location and was used to evaluate the through wall leakage area. The encoded data provides an image that is useful when trying to determine flaw characteristics.

A 3-inch by 6-inch area surrounding the flaw was selected for the encoded examination (see below).

The encoded area encompassed the entire flawed area. The review of the encoded data illustrates that the flawed area has an abrupt change in thickness from nominal (Attachment C). Additionally, the area is essentially absent the normal intermittent thickness readings that are seen within flawed areas of SW piping.

Without the normal intermittent responses the area needs to be conservatively bounded by where the inside surface response is initially lost. In doing so this results in a flaw that is 2.327-inches circumferentially by 1.50-inches axially with a remaining wall thickness of 0.00-inches (Attachments A, B and C).

During the angle beam exam the flaw could be seen in all four directions which is not typical for planar flaws. For evaluation purposes the flaw should considered non-planar.

Signature Date Design Engineering Review:

Signature Date

/-

WO-40260904-02, UT Report Summary Page 2 of 5

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~ENEHR 1-0 SEABROOK Attachment A (Encoded Exam Screen C lref-measiScan:237i 7i.I apture) kfqi. 1Disfta t.eay.

Data SamIC LhUn Vw.;

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Total Length of Flaw in the Circumferential Direction, 2.367" WO-40260904-02, UT Report Summary Page 3 of 5

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Attachment C (Encoded Exam Screen Capture)

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Typical Abrupt Loss of Inside Surface Response WO-40260904-02, UT Report Summary Page 5 of 5