L-2017-050, Fifth Ten-Year Lnservice Inspection Interval Relief Request No. 5

Fifth Ten-Year Lnservice Inspection Interval Relief Request No. 5

ML17093A457
Person / Time
Site:	Turkey Point
Issue date:	03/22/2017
From:	Guth M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2017-050
Download: ML17093A457 (18)

Text

• l=PL.

March 22, 2017 L-2017-050 10 CFR 50.55a U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001 Re: Turkey Point Unit 4 Docket Nos. 50-251 Renewed Facility Operating Licenses DPR-41 Fifth Ten-Year lnservice Inspection Interval Relief Request No. 5 Pursuant to 10 CFR 50.55a(z)(2), Florida Power & Light Company (FPL) requests Nuclear Regulatory Commission (NRC) for relief from the applicable American Society of Mechanical EngineersSection XI Code (ASME Code) requirements to delay Code repair/replacement activities temporarily and to apply the evaluation methods of ASME Code Case N-513-3, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping Section XI, Division 1,"

to a Class 2 Safety Injection System (Recirculation Test line) with exceptions. The details of the Turkey Point Unit 4 Relief Request No. 5 are enclosed.

Per our discussion on March 21, 2017, due to the unexpected circumstances surrounding this temporary relief request, and the short duration of the proposed alternative, FPL is requesting a verbal authorization for the proposed alternative.

If you have any questions or require additional information, please contact Mitch Guth, Licensing Manager, at (305) 246-6698.

Sincerely, Mitch Guth Licensing Manager Turkey Point Nuclear Plant Enclosure Attachment cc: USNRC Regional Administrator, Region II, USNRC USNRC Senior Resident Inspector, USNRC, Turkey Point Nuclear Plant USNRC Project Manager, Turkey Point Nuclear Plant Florida Power & Light Company 9760 S.W. 344'" Street Homestead, FL 33035

L-2017-050 Enclosure TURKEY POINT UNIT 4 RELIEF REQUEST No. 5

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 Proposed Alternative In Accordance with 10 CFR 50.55a(z)(2)

Hardship or Unusual Difficulty Without Compensating Increase in Level of Quality and Safety To Utilize Code Case N-513-3 at a Higher Maximum Operating Temperature and Pressure and ASME Section XI, Non-Mandatory Appendix C 1.0 ASME Code Component(s) Affected The requested relief pertains to the ASME Class 2, 3/4 inch NPS pipe, line SI-1501R, A312 Type 316, Schedule 80S pipe segment, located on the Turkey Point Unit 4 High Head Safety Injection (HHSI) Pump Recirculation Test Line. This Class 2, 3/4 inch piping segment is located downstream of 4-943G HHSI test line drain valve, and upstream of the 4-874C HHSI recirculation and test return line check valve to refueling water storage tank (RWST).

2.0 Applicable Code Edition The Code of Record for the Turkey Point Unit 4 Fifth 10-year inservice inspection interval is the 2007 Edition through 2008 Addenda of the American Society of Mechanical Engineers (ASME)Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components subject to the limitations and modifications in 10 CFR 50.55a(b).

3.0 Applicable Code Requirements ASME Section XI Code, subsection IWC-3130, Inservice Visual Examinations, paragraph IWC-3132.2, Acceptance by Corrective Measures or Repair Replacement Activity, a component containing relevant conditions is acceptable for continued service if the relevant conditions are corrected by repair/

replacement activity or by corrective measures to the extent necessary to meet the acceptance standards of Table IWC-3410-1.

ASME Section XI, Code Case N-513-3, "Evaluation Criteria for Temporary Acceptance of Flaws in Moderate Energy Class 2 or 3 Piping,Section XI, Division 1," as conditioned in Regulatory Guide (RG) 1.147, Revision 17, "Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1".

Specifically, ASME Code Case N-513-3 states:

The provisions of this Case apply to Class 2 or 3 piping whose maximum operating temperature does not exceed 200°F (93°C) and whose maximum operating pressure does not exceed 275 psig (1.9 MPa).

1

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 ASME Section XI Non-mandatory Appendix C for flaw evaluation as specified in Code Case N-513-3, Section 3, is restricted to 1 inch and greater NPS in other Code references (i.e. IWC-3641).

4.0 Reason for Request

On March 17, during a Turkey Point Unit 4 Boric Acid Corrosion Control (BACC)

Program walkdown, a through-wall leak was identified on the 3/4 inch pipe, which is the Safety Injection system test return line to the Unit 4 Refueling Water Storage Tank (RWST). The location of the leak in this Class 2, 3/4 inch piping is in a vertical run downstream of the HHSI test line drain valve 4-943G, and upstream of the HHSI minimum recirculation check valve, 4-874C, that is upstream of the Unit 4 RWST. The indication causing the leak is planar in nature (observed as a combination of aligned pitting and cracks). The flaw was sized by surface examination as being 0.75 in. long and circumferentially oriented. No other indications were observed on the pipe. As required by the BACC program, actions are underway to inspect 5 additional pipes where similar conditions exist.

Any additional discrepancies will be addressed under the corrective action program.

This pipe segment is in a test line connected to the normal recirculation line that is normally open to the RWST and can be used by either Unit 3 or Unit 4. The leak is located in the normally stagnant leg of the test line and it is only pressurized for normal plant operations when the HHSI pumps are tested or used to fill/test the Safety Injection (SI) accumulator tanks. During the design basis accident when the Emergency Core Cooling system (ECCS) is recirculating water from the containment sump, the RWST is isolated and the line can be pressurized to the HHSI pump discharge pressure.

The repair/replacement of the pipe requires removal of the 4A and 4B HHSI pumps from service because it is a pressure boundary of the common minimum recirculation line. This activity is allowed to be performed and completed within the 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allotted by Technical Specification (TS) 3.5.2, Action d, with the 3A and 3B HHSI pumps operable and Unit 3 in MODE 1, 2 or 3.

On March 18, 2017, Turkey Point Unit 4 entered TS 3.5.2 Action d, and was preparing to commence the Code repair/replacement activities, when Turkey Point Unit 3 experienced a reactor trip with a loss of the 3A 4kV electrical bus.

Subsequent to the Unit 3 reactor trip, the Unit 4 SI pumps were restored to service and Unit 4 exited TS 3.5.2, Action d. The operability of the pipe with the flaw has been demonstrated by analysis for all plant conditions and design basis loading including seismic loads.

Currently, Unit 4 is in Mode 1, and Unit 3 is in Mode 5 and preparing to commence the Cycle 29 refueling outage activities. Under the current plant 2

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 configuration, TS Limiting Condition for Operation (LCO) 3.5.2, Item a. applies.

Specifically, TS LCO 3.5.2.a requires that four HHSI pumps be operable during Modes 1 through 3, with a TS note that clarifies that if the opposite unit is in Modes 4, 5 or 6, two HHSI pumps, associated with the operating unit, are required to be operable.

At the current plant configuration, performing an immediate Code repair/replacement activity to correct the flaw would result in Unit 4 not meeting the LCO requirements of TS 3.5.2.a., which would require entry into TS LCO 3.0.3 and the commencement of unit shutdown within an hour. As such an immediate Code repair/replacement activity would create a hardship based on the potential risks associated with a unit shutdown and the thermal stress cycling of plant components, and emergent equipment issues incurred during shutdown and startup evolutions, with no compensating increase in the level of quality and safety gained by immediate repair of the flaw.

Pursuant to 10 CFR 50.55a(z)(2), FPL requests relief from the applicable ASME Code requirements to delay the repair/replacement activity until after Turkey Point Unit 3 has exited the Cycle 29 refueling outage, as soon as practicable, but no later than 90 days from the approval of this relief.

Relief is requested from the scope provisions of Code Case N-513-3 as follows:

• Maximum temperature of 200°F. The maximum operating temperature of the system is 205°F which would occur at the discharge of the HHSI pumps during the design basis Loss of Coolant (LOCA) recirculation phase of ECCS operation. Because the pipe is not insulated, the temperature at the flaw location will be considerably less assuring that steam flashing that could cause cyclic stresses will not occur.

• Maximum pressure of 275 psig. The piping is normally under the pressure of the RWST head and occasionally slightly above that pressure for testing of the HHSI pumps and accumulator fills. In those cases, the pressure is well within the code case scope. In an accident conditions when the system is in the recirculation mode, the maximum operating pressure of the pipe is 1525 psig. The methodology used to determine the structural integrity of the pipe is based on its physical characteristics and flaw characterization. The higher pressure is accounted for in the analysis and results in lower allowable flaw size as expected. Furthermore, the analysis which includes loading from an Operating Basis Earthquake and Safe Shutdown Earthquake shows significant margin between calculated and allowable stresses. Because the leakage rate calculated at the design pressure is very low (75.6 cc/hr), lateral thrust forces resulting from the leak are negligible in comparison to the design pressure and seismic forces.

3

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0

• Application of ASME Section XI Non-mandatory Appendix C for flaw evaluation as specified in Code Case N-513-3, Section 3 but restricted to 1 inch and greater NPS in other Code references (i.e. IWC-3641). Although the 3/4-inch pipe under evaluation is smaller than this limit, the equations in the analytical procedure in Appendix C for this particular analysis are relevant and are directly applicable to the smaller pipe size without modifications. For this situation, use of Appendix C procedure for 3/4-inch piping is justified.

The through wall flaw has been visually characterized as a 3/4 inch long flaw oriented circumferential and perpendicular to the pipe axis. The orientation and length was also confirmed by the application of PT developer. The evidence of Outer Diameter (OD) pitting and previous operational experience at Turkey Point of other OD initiated flaws from the salt laden environment surrounding the station provides reasonable assurance that the flaw is OD initiated. Characteristics of OD initiated flaws have an aspect ratio that the length is longer at the initiation site (the OD) than the Inner diameter (ID). Ultrasonic examination could not be performed because of the small 3/4 inch pipe diameter. The through-wall flaw was classified as planer in nature.

The pipe design, maximum operating, and normal conditions are as follows:

Design pressure: 1750 psi Design temperature: 300°F Max operating pressure: 1525 psi (Post LOCA recirculation)

Max operating temperature: 205°F (at the HHSI Pump discharge)

Normal operating pressure: < 50 psi (this line location is downstream of a restricting orifice from the HHSI pump and is normally vented to the RWST, only seeing head height of the RWST)

Normal operating temperature: ambient (< 100°F)

An ASME Section XI Appendix C flaw evaluation has been performed as required by Code Case N-513-3 for the maximum operating conditions as well as the normal operating conditions and found to be acceptable (Attachment 1).

FPL will implement all other applicable requirements of the ASME Code and Code Case N-513-3 for which relief has not been specifically requested and authorized by the NRC staff. Accordingly, section 2(h) of Code Case N-513-3 requires the repair or replacement to occur no later than when the predicted flaw size exceeds the acceptance criteria, or the next scheduled outage, whichever occurs first.

Regulatory Guide (RG) 1.147, Revision 17, Inservice Inspection Code Case Acceptability, ASME Section XI, Division, also specifies, as a condition for using 4

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 Code Case N-513-3, that repair or replacement activities temporarily deferred under the provisions of this Code Case shall be performed during the next scheduled outage. However, FPL will perform the necessary Unit 4 repairs as soon as practicable after the Unit 3 cycle 29 refueling outage, but no later than 90 days from the approval of this relief.

5.0 Proposed Alternative and Basis for Use The 10 CFR Section 50.55a(g)(4) specifies that ASME Code Class 1, 2, and 3 components must meet the requirements except for the design and access provisions and the pre-service examination requirements, set forth in the ASME Code Section XI to the extent practical with the limitation of design, geometry and materials of construction of the components.

Paragraph 50.55a(z) of 10 CFR Part 50 states in part that alternatives to the requirements of 10 CFR 50.55a paragraphs (b) through (h) may be used when authorized by the NRC if the licensee demonstrates (1) the proposed alternatives would provide an acceptable level of quality and safety, or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

FPL is requesting authorization of an alternative to the requirements of the ASME Code Section XI, IWC-3132.2 pursuant to 10 CFR 50.55a(z)(2), since compliance with the specified Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

FPL proposes to temporarily accept the as-found condition (i.e. through-wall flaw) to allow continued Unit 4 operation in Mode 1 until such time as the two Unit 3 SI pumps are operable and Unit 3 is in MODES 1, 2 or 3. It is expected the Unit 4 Code repair/replacement activities will be completed as soon as practicable after the Turkey Point Unit 3 outage, but no later than 90 days from approval of this relief.

Although the scope limitations of Code Case N-513-3, "Evaluation Criteria for Temporary Acceptance of Flaws in Class 2 & 3 Piping, Section Xl, Division I, are not met for the maximum operating conditions for this line, the normal operating temperatures and pressures are within the limitations of the Code Case. However, the guidance of the Code Case is followed since it provides criteria for analytical evaluation, and rules for temporary acceptance of flaws in piping.

The provisions of Code Case N-513-3 Section 2, Procedure, were applied as follows:

5

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 (a) Flaw size characterization is by visual examination and direct measurement:

3/4 inch in length and oriented circumferentially.

(b) Flaw is characterized as a through-wall planar flaw.

(c) The flaw was evaluated as a single flaw.

(d) Flaw evaluation was performed per Non-mandatory Appendix C and is attached (Attachment 1).

(e) FPL will perform a monthly direct visual examination and the application of PT developer to the area with the identified through-wall flaw to validate that the flaw has not grown and is still supported by the flaw evaluation.

(f) FPL will perform a daily visual walkdown of the leak location to confirm the analysis conditions from the visual examinations remains valid, i.e. no new significant leakage.

(g) The flaw evaluation is documented in Attachment 1. It is the basis for considering the pipe section as operable, but degraded/non-conforming with compensatory measures.

The flaw evaluations shows that the maximum allowable flaw size at the maximum operating pressure is ~1.4 inches in length (determined by the intersection of a horizontal line from the red square titled Bending Stress at Flaw Location and allowable bending stress curve in Figure 2, Attachment 1). This represents a factor of safety of 1.87 compared to the maximum allowable flaw size. The flaw evaluation performed did not perform crack growth analysis and hence the leak will be evaluated daily and a PT performed monthly. Negligible flaw growth is expected for the OD stress corrosion (SCC) mechanism, since the pipe normal operating conditions of ambient temperature and low RWST water head pressure are not a significant driver for SCC. In the short duration of this relief request it is not expected to grow significantly. The proposed alternative is to monitor the flaw through frequent periodic inspections of the leak. If the monthly measurement increases from the present by 1/16 inch in either direction (allowing 1/16 inch for measurement uncertainty), then the growth rate will be re-examined to verify the structural analysis conclusions and predicted growth rate.

(h) FPL will repair or replace the degraded portions of the 3/4 inch pipe downstream of 4-943G and upstream of 4-874C after the 3A 4kV electrical bus has returned to service and the Safety Injection System Technical Specifications can be met with the Unit 4 pumps 4A and 4B out of service but no later than 90 days after the relief request is approved. The potential impact to offsite dose has been evaluated for the leakage rate that could be present during the design basis accident. In accordance with UFSAR Chapter 14, Safety Analysis and related 6

TURKEY POINT UNIT 4 FIFTH INSPECTION INTERVAL RELIEF REQUEST NUMBER 5, REVISION 0 documents, leakage identified in the Emergency Core Cooling System must be tracked and managed such that the cumulative rate of all leaks does not exceed 2325 cc/hr. An estimate of the leakage from the pipe determined a potential leakage rate of 75.6 cc/hr for maximum pressure conditions at 1525 psig. This would result in a cumulative leakage rate from the Emergency Core Cooling System of less than 1525.3 cc/hr for Unit 3 and 1518.9 cc/hr for Unit 4. As such, the leakage rate is within the allowable limit.

The potential for flooding from the leakage was reviewed. As noted above, the maximum leakage rate has been determined to be 75.6 cc/hr. There is no equipment in the area that would be affected since the spray would be limited and captured within the penetration. The cumulative volume would be small and drain to the sumps in basement of the Auxiliary Building where it would be contained and pumped to the Radwaste System.

6.0 Duration of Proposed Alternative The requested temporary relief will apply until repair/replacement activities are completed as soon as practicable after the Unit 3 Cycle 29 refueling outage, but no later than 90 days from approval of this relief.

7.0 Precedent In March 2015, the NRC granted for Peach Bottom Atomic Power Station, Units 2 and 3, and Quad Cities Nuclear Power Station, Units 1 and 2 a similar request for relief from the ASME CODE. Specifically, relief was approved from the maximum operating pressure applicability requirements of Code Case N-513-3 (ADAMS Accession No. ML15043A496).

8.0 Attachments

1. Intertek Flaw Evaluation of a Through-wall Indication in 3/4-inch Pipe in the Safety Injection-Turkey Point Plant, Revision 2 7

L-2017-050

March 20, 2017 Mr. Juan Pallin Engineering Director Turkey Point Nuclear Power Station 9760 SW 344th Street Homestead, Florida 33035 RE: Flaw Evaluation of a Through-wall Indication in 3/4-inch Pipe in the Safety Injection System - Turkey Point Plant, Revision 2

Dear Mr. Pallin:

The purpose of this letter is to transmit results from an ASME Section XI flaw evaluation performed on a 3/4-inch pipe section in a Class 2 safety injection system. The pipe was found to be leaking from a circumferential indication. Code Case N-513-3 was used in this evaluation.

A discussion of the analysis and findings are given in the attachment to this letter. With this revision, we included checked/verifier signature for quality assurance.

If you have any questions or need any additional information, you can contact me in Intertek AIMs Santa Clara, California office at (408) 636-5322.

Sincerely, Russell C. Cipolla Principal Engineer RCC/web Attachment cc: M. Liu W. Buehler Intertek AIM 3510 Bassett Street Santa Clara California 95054-2704 408.745.7000 Fax 408.734.0445 16100 Cairnway Drive, Suite 310 Houston Texas 77084-3597 832.593.0550 Fax 832.593.0551

Attachment Flaw Evaluation for 3/4-inch Safety Injection Pipe with Through-wall Indication (3-20-2017, Rev. 2)

1.0 INTRODUCTION

A through-wall indication was found in safety injection pipe as evident of visible leakage; weepage in terms of 3 drops per minute (Ref. 1). The location of the leak was on the vertical run of the pipe just below the grouting at a penetration. The indication causing the leak is planar in nature (reported as a combination of aligned pitting and cracks). The flaw was sized by surface examination as being 0.75 in. long and circumferentially oriented. No other indications were observed on the pipe.

The objective of this analysis is to determine the structural integrity of the pipe for temporary acceptance based on Code Case N-513-3 (Ref. 2) until the pipe can be repaired.

2.0 N-513 METHODOLOGY Code Case N-513 provides the procedures and acceptance criteria for temporary acceptance of Class 2 or 3 piping that has degraded in service. The degradation can include conditions when a through-wall leak is present. The scope of N-513 is limited to moderate energy systems where operating pressures do not exceed 275 psig and operating temperatures do not exceed 200oF.

The application of N-513-3 to the safety injection (SI) piping is appropriate under the analysis conditions with the following clarification:

1) The operating pressure for the SI pipe may exceed 275 psi during postulated accident events. The conditions that could lead to the operating pressure exceeding 275 psi were reviewed by FPL where it was determined that pressures will exceed 275 psi under post-LOCA recirculation mode only. All other conditions including test conditions will meet the moderate energy definition for maximum pressure. The pressure in this line will be the static head from the tank (~50 psi). Even for post-LOCA assumptions, the procedures in N-513 are still applicable and can be used as guidance to established structural integrity. This has been an industry practice in support of formal relief requests.

2) The maximum operating temperature for the piping is 205oF which is just above the N-513 limit. However, this temperature represents the fluid temperature at the SI pump.

The 3/4-inch pipe is uninsulated, approximately 50 feet away from the pump, and is stagnant. Under such conditions, the piping will be at ambient conditions (below 200oF) and within the scope of N-513. It should be noted that the intent of the N-513 is to not permit temperatures to exceed the boiling point of water (212oF) in order to eliminate the water flashing to steam in a leak condition. Even at the maximum operating temperature of 205oF, there is no potential for steam flashing to occur.

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-1

3) The flaw was sized by surface examinations to establish the circumferential extent of the leak. The N-513 procedure requires the flaw be characterized by volumetric examination or by physical measurement. The full pipe circumference is subject to this requirement in order to size the length and depth of all flaws in the cross-section. In this case, the apparent cause of the through-wall flaw is pitting or stress corrosion cracking initiating on the outside surface. Given that such a flaw would propagate through the thickness from the OD side, it is likely that the extent of the flaw along the inside surface would not exceed the OD length. This condition of initiation and propagation can be characterized by physical measurement, as permitted by N-513, and would adequately detect and size the through-wall length of all flaws that may be present in the cross-section.

4) Case N-513-3 evaluates planar flaws by reference to the procedures and acceptance criteria of Appendix C of ASME Section XI (Ref. 3). These procedures were intended for piping applications where the pipe size is NPS 1 or greater as defined in IWC-3641.

Although the 3/4-inch pipe under evaluation is smaller than this limit, the equations in the analytical procedure in Appendix C for this particular analysis are relevant and are directly applicable to the smaller pipe size without modifications. For this situation, use of Appendix C procedure for 3/4-inch piping is justified.

Exceptions to N-513 scope any discussed above should be addressed to a relief request to the NRC to permit continued operation until repairs can be performed.

3.0 DESIGN AND OPERATING DATA The pipe under evaluation is 3/4-inch NPS, schedule 80s and was designed to ASME B31.1.

The pipe material is SA-312 Type 316 stainless steel. The design and operating data were obtained from Refs. 4 and 5.

Design pressure 1750 psi Design temperature 300oF Max operating pressure 1 1525 psi Max operating temperature 205oF The piping stresses at the flaw location were determined by FPL by calculation given in Ref. 5 for a pressure of 1525 psi, as summarized below:

Eq. 11 Stress: 2599 psi Eq. 12 (OBE) 4774 psi Eq. 12 (SSE) 8942 psi The resulting membrane stress and bending stress for use in the analysis were determined to be M = 2599 psi, B = 2175 psi (Level B), and B = 6343 psi (Level D). Service levels B and D are assumed for evaluation purposes to ASME Code flaw evaluation procedures in Appendix C of Section XI.

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-2

4.0 ANALYSIS RESULTS The procedures of Appendix C of Section XI for planar flaws in austenitic wrought pipe were applied as specified by N-513-3. The procedures for limit load analysis of C-5300 were used to determine the allowable bending and membrane stresses for the pipe. The acceptance criteria of circumferential flaws include structural factors on primary membrane and bending loads (i.e.,

SFM and SFB) given in C-2621:

Service Level B: SFM = 2.4, SFB = 2.0 Service Level D: SFM = 1.3, SFB = 1.4 Two pressure cases were evaluated, p = 275 psi (N-513 limit) and p = 1525 psi (maximum operating pressure for the piping). The results for p - 275 psi are given in Figure 1 for occasional loading for design limits of 1.2 Sh (OBE) and 2.4 Sh per B31.1 design. These are assumed to be equivalent to Level B and D loading condition in ASME Section XI for comparing with the flaw acceptance criteria. The applied bending stress at the flaw location is less than the allowable bending stress in accordance with C-5311 of Appendix C with margin.

The calculation results for the higher pressure case of p = 1525 psi is given in Figure 2 where the applied bending stress at the flaw location is less than the allowable bending stress with margin. The allowable membrane stress in accordance with C-5312 of Appendix C is shown in Figure 3. The applied membrane stresses for both pressure cases do not exceed the allowable membrane stress limit.

Regarding flaw size, there is approximately a factor of two margin or greater on flaw length at the point when the acceptance criteria is just met. This margin provides additional assurance towards NDE sizing uncertainties that may exist. The allowable through-wall length can be determined from the figures by the intersection of a horizontal line passing through the applied stress (plotted red square) with the allowable bending or membrane stress curve. The minimum allowable through-wall length is approximately 1.4 in. for the higher pressure case under SSE loading (Figure 2b).

5.0 CONCLUSION

S The following conclusions are made:

1) The evaluation of the leaking flaw in the 3/4-inch safety injection pipe meets the flaw acceptance criteria of Appendix C of ASME Section XI as required by N-513-3 for the evaluation and temporary acceptance of a leaking planar flaw.

2) There are inherent margins in excess of the required structural analysis factors. These margins translate to approximately a factor of two on the NDE flaw length used in the evaluation.

3) There are some areas where the flaw evaluation does not explicitly comply with the scope of N-513-3 and supporting references. However, there are valid technical justifications as described in Section 2.0 above that support the use of N-513-3 for temporary acceptance of the detected flaw, subject to request for relief from the NRC.

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-3

REFERENCES

1. FPL Report 17-042, "4-943G Downstream Pipe," Reference AR 02191993, (March 18, 2017).

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, (January 26, 2009).

3. ASME Section XI, "Rules for lnservice Inspection of Nuclear Power Plant Components,"

(2015 Edition).

4. Excerpts from Bechtel Calculation C-499-310, "Walkdown Package No. Sl-4-11-3,"

(July 1987).

5. "Pipe Stress Hand Calculation," FPL POD 02101993, (March 18, 2017).

Originated By: CheckedNerified by:

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Project Engineer Project Verifier d<1 H~bJ17 Date lntertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-4

Flaw Evaluation Occasional Loads - 1.2 Sh (p = 275 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Bending Stress, (ksi) 50 40 30 Critical Bending Stress 20 Allowable Bending Stress TW Flaw Length Bending Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches) a) Occasional Loads (Eq. 12) - OBE Flaw Evaluation Occasional Loads - 2.4 Sh (p = 275 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Bending Stress, (ksi) 50 40 30 Critical Bending Stress 20 Allowable Bending Stress TW Flaw Length Bending Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches) b) Occasional Loads (Eq. 12) - SSE Figure 1 Flaw Analysis Results for Bending Loads (p = 275 psi)

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-5

Flaw Evaluation Occasional Loads - 1.2 Sh (p = 1525 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Bending Stress, (ksi) 50 40 30 Critical Bending Stress Allowable Bending Stress 20 TW Flaw Length Bending Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches) a) Occasional Loads (Eq. 12) - OBE Flaw Evaluation Occasional Loads - 2.4 Sh (p = 1525 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Bending Stress, (ksi) 50 40 30 Critical Bending Stress 20 Allowable Bending Stress TW Flaw Length Bending Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches) b) Occasional Loads (Eq. 12) - SSE Figure 2 Flaw Analysis Results for Bending Loads (p = 1525 psi)

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-6

Flaw Acceptance Membrane Loads - 1.2 Sh (p = 275 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Membrane Stress, (ksi) 50 40 30 Critical Membrane Stress 20 Appendix C Allowable Membrane Stress TW Flaw Length Membrane Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches)

Flaw Acceptance Membrane Loads - 1.2 Sh (p = 1525 psi) 80 3/4-inch NPS 70 D = 1.05" t = 0.154" 60 Membrane Stress, (ksi) 50 40 30 Critical Membrane Stress 20 Appendix C Allowable Membrane Stress TW Flaw Length Membrane Stress at Flaw Location 10 0

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 TW Degradation Length, L (inches)

Figure 3 Flaw Analysis Results for Membrane Loads (p = 275 and 1525 psi)

Intertek AIM Florida Power & Light Company N-513-3 Evaluation, Rev. 2 March 2017 A-7