PNP 2015-076, Relief Request Number RR 4-24 - Proposed Alternative, Use of Alternate ASME Code Case N-770-1 Baseline Examination

Relief Request Number RR 4-24 - Proposed Alternative, Use of Alternate ASME Code Case N-770-1 Baseline Examination

ML15269A035
Person / Time
Site:	Palisades
Issue date:	09/26/2015
From:	Vitale A Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PNP 2015-076, RR 4-24
Download: ML15269A035 (109)

Text

{{#Wiki_filter:* ~Entergy Entergy Nuclear Operations, Inc. Palisades Nuclear Plant 27780 Blue Star Memorial Highway Covert, MI 49043-9530 Tel 269 764 2000 Anthony J. Vitale Site Vice President PNP 2015-076 September 26, 2015 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Relief Request Number RR 4 Proposed Alternative, Use of Alternate ASME Code Case N-770-1 Baseline Examination Palisades Nuclear Plant Docket 50-255 Renewed Facility Operating License No. DPR-20

Dear Sir or Madam:

Pursuant to 10 CFR 50.55a(z)(2), Entergy Nuclear Operations, Inc. (ENO) hereby requests NRC approval of a request for relief for a proposed alternative for the Palisades Nuclear Plant (PNP). The proposed alternative is described in the enclosed relief request number RR 4-24. This relief request is associated with the use of an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Code Case N-770-1, as conditioned by 10 CFR 50.55a(g)(6)(ii)(F)(1) and 10 CFR 50.55a(g)(6)(ii)(F)(3). The proposed duration of this relief request is to the end of the current fourth 10-year interval and through the first refueling outage in the fifth 10-year interval, scheduled for spring 2017. The fourth interval will end on December 12, 2015 and the fifth interval will begin on December 13, 2015. To support the ongoing PNP refueling outage, ENO requests approval of this alternative by September 27, 2015. This submittal contains no proprietary information and no commitments. I declare under penalty of perjury that the foregoing is true and correct. Executed on September 26,2015.

PNP 2015-076 Page 2 of 2 AJV/jse

Enclosure:

Entergy Nuclear Operations, Inc., Palisades Nuclear Plant, Relief Request Number RR 4-24 Proposed Alternative cc: Administrator, Region III, USNRC Project Manager, Palisades, USNRC Resident Inspector, Palisades, USNRC

ENCLOSURE ENTERGY NUCLEAR OPERATIONS, INC. PALISADES NUCLEAR PLANT PROPOSED ALTERNATIVE in Accordance with 10 CFR SO.SSa(z)(2) Hardship Without a Compensating Increase in Quality and Safety

1. ASME Code Component(s) Affected I Applicable Code Edition Components / Numbers: See Table 1 Pressure Retaining Dissimilar Metal Piping Butt Welds Containing Alloy 821182 Code of Record: American Society of Mechanical Engineers (ASME) Section XI, 2001 Edition through 2003 Addenda as amended by 10 CFR 50.55a ASME, Section XI, 2007 Edition with 2008 Addenda as amended by 10 CFR 50.55a ASME Code Case N-770-1 , "Alternative Examination Requirements and Acceptance Standards for Class 1 PWR Piping and Vessel Nozzle Butt Welds Fabricated with UNS N06082 or UNS W86182 Weld Filler Material With or Without Application of Listed Mitigation Activities, Section XI, Division 1" N-770-1 Inspection Item: B

Description:

Class 1 PWR pressure retaining Dissimilar Metal Piping and Vessel Nozzle Butt Welds Containing Alloy 821182 Unit / Inspection Interval: Palisades Nuclear Plant (PNP) / Fourth 10-Year Interval December 13, 2006 through December 12, 2015 and Fifth Interval December 13, 2015 through December 12, 2025

2. Applicable Code Requirements For the fourth interval, the applicable code is the ASME Boiler and Pressure Vessel Code, Rules for Inservice Inspection of Nuclear Power Plant Components, Section XI, 2001 Edition through 2003 Addenda, as amended by 10 CFR 50.55a. For the fifth interval, the applicable code is the ASME Boiler and Pressure Vessel Code, Rules for Inservice Inspection of Nuclear Power Plant Components, Section XI , 2007 Edition with the 2008 Addenda, as amended by 10 CFR 50.55a.

With the issuance of a revised 10 CFR 50.55a in June 2011, the Nuclear Regulatory Commission (NRC) staff incorporated, by reference, Code Case N-770-1. Specific 1

ENCLOSURE implementing requirements are documented in 10 CFR 50.55a(g)(6)(ii)(F) and are listed below: A. 10 CFR 50.55a(g)(6)(ii)(F)(1), effective date August 22, 2011, requires "licensees of existing, operating pressurized water reactors as of July 21, 2011, shall implement the requirements of ASME Code Case N-770-1, subject to the conditions specified in paragraphs (g)(6)(ii)(F)(2) through (g)(6)(ii)(F)(10) of this section, by the first refueling outage after August 22,2011." B. Regulation 10 CFR 50.55a(g)(6)(ii)(F)(3) states that baseline examinations for welds in Code Case N-770-1, Table 1, Inspection Items A-1, A-2, and B, shall be completed by the end of the next refueling outage after January 20, 2012. C. Regulation 10 CFR 50.55a(g)(6)(ii)(F)(4) states that the axial examination coverage requirements of Code Case N-770-1, -2500(c) may not be considered to be satisfied unless essentially 100 percent coverage is achieved. The welds covered by this proposed alternative are classified as Inspection item B (described below) for which visual and essentially 100 percent volumetric examination, as amended by 10 CFR 50.55a(g)(6)(ii)(F)(4), are required, per NRC interpretation. ASME Code Case N-77Q-1 as Amended by 10 CFR SO.SSa(g)(6)(ii)(F)(4) CLASS 1 PWR Pressure Retaining Dissimilar Metal Piping and Vessel Nozzle Butt Welds Containing Alloy 821182 Insp Parts Examined Extent and Frequency of Examination Item Bare metal visual examination once per interval. Unmitigated butt weld Essentially 100% volumetric examination for axial and at Cold Leg operating circumferential flaws in accordance with the applicable temperature (-2410) ~ B requirements of ASM E Section XI, Appendix VIII, every second 525°F (274°C) and < inspection period not to exceed 7 years. Baseline examinations 580°F (304°C) shall be completed by the end of the next refueling outage after January 20, 2012. As defined by ASME Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds, Section XI, Division 1," essentially 100% means greater than 90% of the examination volume of each weld where reduction in coverage is due to interference by another component or part geometry. ASME Section XI, Appendix VIII, Supplement 10, "Qualification Requirements for Dissimilar Metal Piping Welds," is applicable to dissimilar metal (OM) welds without cast materials. 2

ENCLOSURE

3. Reason for Request

The welds listed in Attachment 1, Table 1, of this request did not satisfy the exam coverage required by ASME Code Case N-770-1, as conditioned by 10 CFR 50.55a(g)(6)(ii)(F). The relevant conditions for this request for alternative are ASME Section XI Code Case N-770-1, and 10 CFR 50.55a(g)(6)(ii)(F) items (3) and (4), which address performing the required baseline examination and attaining the required examination coverage. 10 CFR 50.55a(g)(6)(ii)(F)(3) requires that Inspection Item B receives a baseline examination by the end of the first refueling outage after January 20, 2012. 10 CFR 50.55a(g)(6)(ii)(F)(4) provides the following exception to ASME Code Case N-770-1 ,

  "the axial examination coverage requirements of Paragraph-2500(c) may not be considered to be satisfied unless essentially 100 percent coverage is achieved."

Relief is requested from Code Case N-770-1 , -2500, Examination ReqUirements, as conditioned by 10 CFR 50.55a(g)(6)(ii)(F)(3) and 10 CFR 50.55a(g)(6)(ii)(F)(4) that essentially 100% coverage must be achieved of the inspection volume for the baseline and future required volumetric examinations. Hardship In accordance with 10 CFR 50.55a (z)(2), relief is requested for the components listed in Attachment 1, Table 1, on the basis that the required examination coverage of essentially 100 percent is unattainable due to hardship without a compensating increase in quality and safety. During the ongoing refueling outage, Entergy Nuclear Operations, Inc. (ENO) is performing volumetric examinations on one hot leg branch connection weld and eight cold leg branch connection welds using an encoded phased array ultrasonic testing (UT) examination technique qualified under the Performance Demonstration Initiative (POI) qualification program. For the eight cold leg welds, the required examination coverage of essentially 100 percent is not attainable. These cold leg welds are listed in Attachment 1, Table 2. Coverage requirements could not be attained for these welds because the contour of the weld along the periphery of the branch connection nozzles is different than the weld contour in the branch connection nozzle mockup used for qualification of the examination technique in the POI program (see Figure 1 in Attachment 2). The piping fabricator applied additional weld, making a taper transition weld instead of following the contour of the pipe outside diameter. The weld contour of the mockup was based on plant design drawings of the nozzles with no taper. The weld contour of the installed branch connection nozzles is such that the examination technique is not able to achieve any coverage of the circumferential direction to detect axial flaws for all eight cold leg welds. The design drawings for these nozzle configurations specified to weld to the run pipe outside diameter and to blend a 11A inch radius on the nozzle base material down to the OM weld between the Alloy 600 nozzle and the PCS piping. However, for each of these nozzles during original fabrication, rather than remove nozzle base material, the weld was tapered to the nozzle base material, resulting in a tapered weld profile around the periphery of the nozzle. 3

ENCLOSURE There are a couple of options to achieve the required axial flaw scan coverage of the subject welds during this outage. One option would be to manually grind the welds down so that the weld contour is consistent with the weld contour of the mockup used during the qualification of the volumetric examination technique. Due to the location of the welds, and the time duration required to achieve the required weld contour, the personnel dose incurred would be significant. It is estimated, based on dose rate measurements taken in the vicinity of the welds, that personnel radiological exposure would be approximately 41 Rem for the eight welds (see Table 3 in Attachment 1). This is based on an estimated 20 man hours of manual grinding per weld, two hours for surface examination of each weld, walkdowns, and mobilization and demobilization of equipment. In addition, prior to actual start of work in the field, mockups would need to be fabricated for training purposes in order to ensure that personnel are capable of providing the required weld profile, performing the task without violating minimum wall tolerances with the efficiencies needed to minimize dose. A second option for axial flaw scan coverage would be to attempt a requalification of the examination technique for the current weld configuration. This would require modifying the encoded phased array equipment and fabricating more mockups to match the weld contour of the installed branch connection nozzles, potentially change the angle of the probe or a probe redeSign, and then repeating the lengthy examination requalification process. Four cold leg welds have an additional physical obstruction affecting the ability to achieve coverage requirements. There is a concrete pipe whip restraint in close proximity to each of the cold legs that limits placement and travel of the encoded phased array scanner and probe (see Figure 2 in Attachment 2). This obstruction prevents the automated scanner from rotating 360 degrees around the weld. The ultrasonic probe rotates slightly greater than 180 degrees. Along the 50 percent of these four welds that were examined (1800 of the 3600 periphery), 100 percent of the code-required weld volume could be obtained in this direction and no circumferential flaws were identified in the scanned areas. In order to obtain required circumferential scan coverage for the four weld volumes that are obstructed by the concrete pipe whip restraints, an examination technique that can achieve the required coverage despite the concrete pipe whip restraint obstructions would need to be developed and qualified. ENO plans to attempt to develop and qualify the procedures for this configuration over the next fuel cycle and implement during the next refueling outage, 1R25, in 2017. Performing the volumetric examinations, using ASME Code, Section XI, Appendix VIII, Supplement 10 procedures, equipment and personnel, qualified to examine the configuration of the cold leg nozzles with the tapered weld, during the next scheduled refueling outage (1 R25), would avoid the significant radiological dose to personnel that would be incurred by manually grinding the welds.

4. Proposed Alternative and Basis for Use Proposed Alternative

1) Perform periodic system leakage tests in accordance with ASME Section XI Examination Category B-P, Table IWB-2500-1.

4

ENCLOSURE

2) Perform a volumetric examination, using ASME Code, Section XI, Appendix VIII, Supplement 10 qualified procedures, equipment and personnel, on each of the eight subject welds of this alternative during the next scheduled refueling outage (1 R25).

3) Until the next scheduled refueling outage, if unidentified primary coolant system (PCS) leakage increases by 0.15 gpm above the WCAP-16465NP baseline mean, and is sustained for 72 hours, ENO will take action to be in Mode 3 within 6 hours and Mode 5 within 36 hours, and perform bare metal visual examinations of the eight subject welds of this alternative, unless it can be confirmed that the leakage is not from these welds.

Entergy will perform appropriate actions to meet ASME Section XI Code Case N-770-1 baseline examinations for those dissimilar metal welds not meeting the examination coverage requirements during the 2015 refueling outage prior to startup from the planned spring 2017 refueling outage. Basis for Use The POI qualified encoded phased array UT technique was able to achieve the volumetric coverage requirements on the one hot leg weld examination performed during the current refueling outage on September 22, 2015. Examination of the two inch hot leg drain nozzle (weld identification number PCS-42-RCL-1 H-3/2) was completed with 100% coverage with no axial or circumferential flaws identified. The operating temperature of a component is a primary factor influencing the initiation of Primary Water Stress Corrosion Cracking (PWSCC). Research by the Electric Power Research Institute (EPRI) (Reference 10) indicates that the difference in the operating temperature between hot leg locations and cold leg locations is sufficient to significantly influence the time to initiation of PWSCC, with the susceptibility increasing with temperature. The research reports PWSCC is least likely to occur in cold leg temperature penetrations. The hot leg temperature is approximately 583 of whereas the cold leg temperature is approximately 537 of. This means there is a lower probability of crack initiation, and a slower crack growth rate [References 11 and 12], in cold leg locations. The encoded phased array UT technique that was POI qualified for use on each of the eight cold leg welds was applied to the extent practicable while still remaining within its qualification requirements. However, due to the cold leg weld contours and concrete pipe whip restraint obstructions, no coverage was possible for axial flaw scans and only limited examination coverages were possible for circumferential flaw scans. Because the hot leg weld is a higher operating temperature location, it is a more likely location for PWSCC to occur than in one of the cold leg welds. Since no weld flaws were identified in the hot leg weld, it is less likely that a PWSCC-induced flaw is present in the portions of the cold leg welds that could not be examined during this current outage. , Table 1, lists the eight cold leg welds that could not be examined to Code Case N-770-1 examination coverage requirements. Structural Integrity of these Regions Cold Leg Crack Growth Analysis 5

ENCLOSURE Structural Integrity Associates (SI) evaluated postulated flaws in the cold leg nozzles in the following calculations provided in Attachment 4: SI Calculation, File No. 1400669.323, "Crack Growth Analysis of the Cold Leg Bounding Nozzle," Revision 0, dated May 11, 2015. SI Calculation, File No. 1400669.320, "Finite Element Model Development for the Cold Leg Drain, Spray, and Charging Nozzles," Revision 0, dated April 3, 2015. SI Calculation, File No. 1400669.322, "Cold Leg Bounding Nozzle Weld Residual Stress Analysis," Revision 0, dated May 5, 2015. In these calculations, SI used a finite element analysis (FEA) approach to evaluate postulated flaws in the cold leg nozzles. These models were used to perform weld residual stress evaluations and calculations of stress intensity factors in the DM welds. Utilizing these new stress intensity factor distributions for postulated circumferential and axial flaws in the DM welds, crack growth due to PWSCC was evaluated for the cold leg configuration. Crack growth durations were then plotted on charts to show the service life of the cold leg configuration based on crack growth from an assumed initial flaw depth of 0.025 inch. It should be noted that PWSCC was the only crack growth mechanism considered in this evaluation (Le., PWSCC growth of a postulated axial and circumferential flaw in the weld). No credit is taken in the calculations for crack initiation time or crack growth rate reduction post weld heat treatment. Using the FEA approach, the time for an initial 0.025-inch deep flaw to grow to 75% through-wall is 64.5 years for the bounding axial flaw (77 years to go 95% through-wall) and 55.6 years for the circumferential flaw (66.2 years to go 95% through-wall). By the 1R25 refueling outage, PNP will have operated for 28.8 effective full power years (Reference 22). Basis for Assuming No Weld Repair In Calculations The presence of an initial weld repair from plant construction (e.g., extending 50% of the wall thickness from the inside diameter (ID)) is often assumed when modeling Alloy 82/182 piping butt welds. Often for piping butt welds, the residual stress calculated for the ID is a small tensile value, or even compressive, in the absence of an assumed weld repair. In such cases, the possibility of a significant weld repair being present on the weld ID can have a relatively large effect on the calculated stresses, especially on and near the ID surface. However, for the Alloy 82/182 branch connection welds at Palisades Nuclear Plant (PNP), there are two reasons why it is not necessary to include a weld repair assumption in the analysis. First, the design for this weldment specifies a 3600 backweld on the ID surfaces of the pipe that is about 0.25 inch thick. This design feature results in elevated residual stress levels at the ID surface prior to the post weld heat treatment (PWHT) being applied. The residual stress levels at the inside surface due to the presence of the backweld are similar to what would be expected due to the presence of a weld repair on the ID surface. Second, any weld repairs would have been made prior to PWHT being applied, and would be expected to extend over a relatively limited circumferential portion of the original weld . Similar to the situation for the elevated residual stresses due to the presence of the 6

ENCLOSURE backweld, the PWHT would relax the residual stresses in the weld repair area, including the substantial relaxation expected at the surface exposed to primary coolant. Moreover, in the unlikely case that initiation occurred in the area of a weld repair, the weld repair would be an additional source of non-axisymmetric crack loading that would tend to drive crack growth in the through-wall direction over a relatively local circumferential region, ultimately resulting in detection of leakage prior to the possibility of unstable pipe rupture. Basis for Five-Cycle Shakedown Assumption in Residual Stress Calculation Operational cycles are frequently included in welding residual stress calculations as a part of determining the operating stress condition. In particular, the standard modeling practice adopted by the xLPR (Extremely Low Probability of Rupture) welding residual stress team, which includes the NRC, national laboratories, and industry participants, specifies that the welded configuration should be cycled between operating conditions and residual conditions to shake down the nonlinear material hardening behavior. Typically, three to five cycles are used to shake down the material's behavior. Since the primary interest from the residual stress analysis is to provide residual stresses for calculating stress corrosion crack growth under normal operating conditions, it is desirable to determine a stabilized residual stress state that will not change under normal operating cycles. The as-welded residual stresses usually contain localized peak stresses at some nodal locations. Applying a few operating cycles will stabilize the stress peaks and valleys due to the slight stress redistribution at elevated temperatures. It has been determined through experience that the residual stresses will stabilize after three to five cycles. Five cycles were used for conservatism . See Reference 2 for additional information. Weld Repair History The manufacturing/quality plan provided in the specification for the PCS piping provides instructions for performing weld repairs based on the results of NDE testing. Any defects identified in the nozzle welds would have been removed prior to final furnace heat treatment of the assembly. These radiographs represent the condition of the subject welds at the time of installation at the site. A search of PNP records did not identify any repairs performed on the subject welds since installation. Cold Leg Nozzle Geometry Detailed information concerning the cold leg nozzle geometry is provided in Figures 3 through 5 in Attachment 2. This information is taken from original design drawings of the nozzles. PCS Leak Detection Capabilities The leak detection methodology presently used by industry is very sensitive. After a number of recent operating events, the industry imposed an NEI 03-0B requirement, to improve leak detection capability. As a result, virtually all pressurized water reactors (PWRs) in the United States, including PNP, have a leak detection capability of less than or equal to 0.1 gpm (Reference B). All plants, including PNP, also monitor seven day moving averages of reactor coolant system leak rates. 7

ENCLOSURE Operators may also be alerted to a leak from a flaw by containment radiation monitoring instrumentation. This instrumentation, required by the Technical Specifications, is capable of detecting a 100 cm/min leak in 45 minutes, based on 1% failed fuel. The PCS is inspected for leaks as the plant is shut down for refueling outages. After refueling, as the plant is returned to power operations, VT-2 visual examinations are performed to detect leakage from the PCS. Operator walkdowns of containment are periodically performed during power operations at lower levels of containment to detect leakage. In the event of a flaw causing leakage in the PCS, the plant would be shut down and placed in a safe condition in accordance with plant procedures. Action response times following a leak detection vary, based on the action level exceeded and range up to containment entry to identify the source of the leak. Action levels have been standardized for all PWRs, and are based on deviations from:

• The seven day rolling average,
• Specific values, and
• The baseline mean.

Leak rate action levels are identified in Pressurized Water Reactor Owners Group (PWROG) report, WCAP-16465, and are stated below: Each PWR utility is required to implement the following standard action levels for reactor coolant system (RCS) inventory balance in their RCS leakage monitoring program. A. Action levels on the absolute value of unidentified RCS inventory balance (from surveillance data): Level 1 - One seven day rolling average of unidentified RCS inventory balance values greater than 0.1 gpm. Level 2 - Two consecutive unidentified RCS inventory balance values greater than 0.15 gpm. Level 3 - One unidentified RCS inventory balance value greater than 0.3 gpm. Note: Calculation of the absolute RCS inventory balance values must include the rules for the treatment of negative values and missing observations.

1. Action levels on the deviation from the baseline mean:

Level 1 - Nine consecutive unidentified RCS inventory balance values greater than the baseline mean [1-1] value. Level 2 - Two of three consecutive unidentified RCS inventory balance values greater than [1-1 + 20], where 0 is the baseline standard deviation. Level 3 - One unidentified RCS inventory balance value greater than [1-1 +30]. These action levels have been incorporated into PNP operating procedures. 8

ENCLOSURE Therefore, with the periodic system pressure tests, outage system walk downs, leakage monitoring, an acceptable level of quality and safety is provided for identifying degradation from PWSCC prior to a safety significant flaw developing.

5. Duration of Proposed Alternative The duration of the proposed alternative for the welds with limited coverage is until the next PNP refueling outage, planned for the spring of 2017.

6. References

1. 10 CFR SO.SSa revision endorsing the 2008 Addenda of Section'" and Section XI, Federal Register #76FR36232, July 21, 2011.

2. ASME Section XI, "Rules For Inservice Inspection of Nuclear Power Plant Components,"

2001 Edition with Addenda through 2003.

3. ASME Section XI, Division 1, Code Case N-460, "Alternative Examination Coverage for Class 1 and Class 2 Welds, Section XI, Division 1."

4. Material Reliability Program: Primary System Piping Butt Weld Inspection and Evaluation Guideline (MRP-139), Revision 1, EPRI, Palo Alto, CA, 2008 [ML1009700671].

S. Nondestructive Evaluation: Procedure for Manual Phased Array Ultrasonic Examination of Dissimilar Metal Welds, EPRI-DMW-PA-1, Revision 3, 101664S, EPRI Palo Alto, CA, 2008.

6. Material Reliability Program, Alloy 82/182 Pipe Butt Weld Safety Assessment for US PWR [Pressurized Water Reactor] Plant Designs (MRP-109): Westinghouse and CE

[Combustion Engineering] Design Plants, EPRI, Palo Alto, CA, 200S [ML042434006].

7. "Changing the Frequency of Inspections for PWSCC Susceptible Welds at Cold Leg Temperatures", in Proceedings of 2011 ASME Pressure Vessels and Piping Conference, July 17-21, 2011, Baltimore, MD.

8. WCAP-1646S-NP, Rev. 0, "Pressurized Water Reactor Owners Group Standard RCS Leakage Action Levels and Response Guidelines for Pressurized Water Reactors,"

Westinghouse Electric Co., September 2006 [ML070310082].

9. Pressurized Water Reactor (PWR) Owner's Group Letter OG-12-89, Transmittal of

      'Final Relief Request Famework' under Relief Request for Large Diameter Cold Leg Locations with Obstructions (PA-MSC-0934)," March 8, 2012.

10. Electric Power Research Institute: PWSCC of Alloy 600 Materials in PWR Primary System Penetrations, EPRI, Palo Alto, CA, 1994, TR-103696 [ML013110446].

11. Materials Reliability Program Crack Growth Rates for Evaluating Primary Water Stress Corrosion Cracking (PWSCC) of Alloy 82,182, and 132 Welds (MRP-11S), EPRI, Palo Alto, CA, 2004, 1006696 [MLOS11 00204].

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ENCLOSURE

7. Attachments

1. Table 1: Weld Examination History Table 2: Weld Inspection Coverages Table 3: Dose Estimate for Weld Removal

2. Figure 1 - PCS Cold Leg Nozzle Typical Nozzle Weld Configuration Showing Material to be Removed Figure 2 - Typical Configuration of Branch Connection Nozzle with Concrete Pipe Whip Restraint Barrier and Coverage Area Figures 3 through 5 - Design Drawings of Nozzle Configurations

3. Nozzle Photographs Showing Concrete Pipe Whip Restraints

4. Supporting Calculations 10

ENCLOSURE ATTACHMENT 1 Table 1: Weld Examination History No. Description ISIWeldlD Location 1R19 1R20 1R21 1R22 1R23 Examinations Examinations Examinations Examinations Examinations Visual PCS-30-RCL-1 A- Surface 2 inch Cold Leg P-50A (Report# 4046

1. (Report# 1R23-Charging Nozzle 11/2 Discharge Leg Exam number PT-14-025) 06-26)

Visual Surface 2 inch Cold Leg PCS-30-RCL-1A- P-50A Suction (Report# 4047

2. (Report# 1R23-Drain Nozzle 5/2 Leg Exam number PT-14-031) 07-28.1)

Surface 3 inch Cold Leg Visual PCS-30-RCL-1 B- P-50B (Report#

3. Pressurizer Spray (Report# VT-10/3 Discharge Leg 1R22-PT Nozzle 10-069) 039)

Visual Surface 2 inch Cold Leg PCS-30-RCL-1 B- P-50B Suction

4. (Report# VT- (Report #1 R23-Drain Nozzle 5/2 Leg 10-048) PT-14-032)

Visual Surface 2 inch Cold Leg PCS-30-RCL-2A- P-50C

5. (Report# VT- (Report# 1R23-Charging Nozzle 11/2 Discharge Leg 09-083) PT-14-019)

Surface 3 inch Cold Leg Visual PCS-30-RCL-2A- P-50C (Report#

6. Pressurizer Spray (Report# VT-11/3 Discharge Leg 1R22-PT Nozzle 09-035) 032)

Visual 2 inch Cold Leg PCS-30-RCL-2A- P-50C Suction

7. (Report# VT-Drain Nozzle 5/2 Leg 09-038) 2 inch Cold Leg Visual Surface PCS-30-RCL-2B- P-50D Suction

8. Drain and (Report# VT- (Report# 1R23-5/2 Leg Letdown Nozzle 10-071 ) PT-14-020)

ENCLOSURE ATTACHMENT 1 Table 2: Weld Inspection Coverages Component 10 Description! NPS N-nO-1 Volume Coverage (%) Circ Flaw Scan Axial Flaw Scan Exam Method and Limitations I Examination Summary UT Encoded Phased Array 2 inch Hot Leg Drain PCS-42-RCL-1 H-3/2 100% 100% No limitations. Nozzle UT Encoded Phased Array 2 inch Cold Leg Weld contour limitation. PCS-30-RCL-1A-11/2 100% 0% Charging Nozzle UT Encoded Phased Array 2 inch Cold Leg Drain PCS-30-RCL-1 A-5/2 50% (approx.) 0% Weld contour limitation and concrete pipe whip Nozzle restraint obstruction. 3 inch Cold Leg Pressurizer Spray UT Encoded Phased Array PCS-30-RCL-1 8-1 0/3 *

• Nozzle 2 inch Cold Leg Drain UT Encoded Phased Array PCS-30-RCL-18-5/2 Nozzle 50% (approx.) 0% Weld contour limitation and concrete pipe whip restraint obstruction.

2 inch Cold Leg UT Encoded Phased Array PCS-30-RCL-2A-11/2 Charging Nozzle *

• 3 inch Cold Leg Pressurizer Spray PCS-30-RCL-2A-11/3 *
• UT Encoded Phased Array Nozzle 2 inch Cold Leg Drain UT Encoded Phased Array PCS-30-RCL-2A-5/2 Nozzle 50% (approx.) 0% Weld contour limitation and concrete pipe whip restraint obstruction.

2 inch Cold Leg Drain UT Encoded Phased Array PCS-30-RCL-28-5/2 and Letdown Nozzle 50% (approx.) 0% Weld contour limitation and concrete pipe whip restraint obstruction. --

     *Volumetric examination not yet completed.

ENCLOSURE ATTACHMENT 1 Table 3: Dose Estimate for Weld Removal 1R24 DOSE RATES (mrem/hr) Walk down Mob/Demob Contour NDE TOTAL DESCRIPTION Area 151 WELD ID CONTACT 30cm G/ A LDWA HOURS DOSE HOURS DOSE HOURS DOSE HOURS DOSE DOSE 2" Cold Leg 1 P-50A PCS-30-RCL-lA-ll/2 200 50 50 5 0.25 27.5 1 110 20 2100 2 100 2338 Charging Nozzle 2" Cold Leg 2 P-50A PCS-30-RCL-1A-5/2 100 30 28 5 0.25 16.5 1 66 20 1260 2 60 1403 Drain Nozzle 3" Cold Leg 3 P-50B PCS-30-RCL-1B-10/3 500 150 50 30 0.25 40 1 160 20 4600 2 300 5100 PZR Spray Nozzle 2" Cold Leg 4 P-50B PCS-30-RCL-1B-5/2 100 40 20 2 0.25 11 1 44 20 1240 2 80 1375 Drain Nozzle 2" Cold Leg 5 P-50C PCS-30-RCL-2A-ll/2 250 150 120 25 0.25 72.5 1 290 20 5900 2 300 6563 Charging Nozzle 3" Cold Leg 6 P-50C PCS-30-RCL-2A-ll/3 1000 500 140 25 0.25 82.5 1 330 20 13300 2 1000 14713 PZR Spray Nozzle 2" Cold Leg 7 P-50C PCS-30-RCL-2A-5/2 80 40 20 2.5 0.25 11.25 1 45 20 1250 2 80 1386 Drain Nozzle 2" Cold Leg Drain 8 P-50D PCS-30-RCL-2B-5/2 500 150 50 30 0.25 40 1 160 20 4600 2 300 5100

  / Letdown Nozzle                                                                                                                                       I Total   301         1205        34250        2220   37976 Walk down - 1 pipefitter and 1 supervisor in the G/A dose rates for 15 minutes per point.

Mob/Demob - 2 pipefitters and 2 laborers, in the G/A and LDWA Contour - I pipefitter right next to the pipe, 1 pipefitter in the G/A, 1 laborer in the LDWA (firewatch) Superviser Oversite - 1 person at all t imes in G/A to LDWA 1840 RP Technician (4% of prep . and inspection dose). 1370 Grand Total 41186 (all dose stated in mrem)

ENCLOSURE ATTACHMENT 2 Figure 1 pes Cold Leg Nozzle Typical Nozzle Weld Configuration Showing Material to be Removed Material Volume Removal Required

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I I

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ENCLOSURE ATTACHMENT 2 Figure 2: Typical Configuration of Branch Connection Nozzle with Concrete Pipe Whip Restraint Barrier and Coverage Area [Note: This is a typical layout for a 00 to 1800 scan area or a 1800 to 3600 scan area. Scan set up determined by pipe flow direction.] VIEW IS BOTTOM LOOKING UP

                           - ________jl--=\*-..:--,.",C                       7\

Tot ..l L.. ngtk of 'tIBld - 27.3' Tot..l L.. ngtk of Scanned - 34.B5' 14.S5 / 27.3 = .53SS " 111121 = 53..SI>7-lliIQl7. of Cod .. R..qU1.... d Volum .. CbUlln .. d 1n ........ ~c"'nn.. d

ENCLOSURE ATTACHMENT 2 Figure 3 NPS 2 Cold Leg Charging Nozzle Weld Configuration Welds PCS-30-RCL-1A-11/2 and PCS-30-RCL-2A-11/2

                      ~----l_1            l I
                                        ~

I I i ~WfLD .

ENCLOSURE ATTACHMENT 2 Figure 4 NPS 3 Cold Leg Pressurizer Spray Nozzle Weld Configuration Welds PCS-30-RCL-1 8-10/3 and PCS-30-RCL-2A-11/3

                                                ~Q
                                                  ~
                    @SPI2A-Y NOIZl;
                         .st4L£ .. 6#*(2'

ENCLOSURE ATTACHMENT 2 Figure 5 NPS 2 Cold Leg Drain and Letdown Nozzle Weld Configuration and NPS 2 Cold Leg Drain Nozzle Weld Configuration Welds PCS-30-RCL-2B-5/2, PCS-30-RCL-1 A-5/2, PCS-30-RCL-1 B-5/2, and PCS-30-RCL-2A-5/2

~N/)rO~

~ PIP{; ,5RfA/O 1Z:) ~1',.,"'r.R "'SLOINe; ~GUOVG i!JJACKIA/6 IlIN$ t>4CIl. GRoov' n. !i'Jt.lNO M&T.4I. "'*~I.D

ENCLOSURE ATTACHMENT 3 Nozzle Photographs Showing Concrete Pipe Whip Restraints

ENCLOSURE ATTACHMENT 4 Supporting Calculations These Structural Integrity Associates, Inc. (SI) supporting calculations provide an analytical basis for the proposed alternative.

1. SI Calculation, File No. 1400669.323, "Crack Growth Analysis of the Cold Leg Bounding Nozzle," Revision 0, dated May 11, 2015.

2. SI Calculation, File No. 1400669.320, "Finite Element Model Development for the Cold Leg Drain, Spray, and Charging Nozzles," Revision 0, dated April 3, 2015.

3. SI Calculation, File No. 1400669.322, "Cold Leg Bounding Nozzle Weld Residual Stress Analysis," Revision 0, dated May 5, 2015.

87 Pages Follow

~Stmcturallntegrlly Associates. Inc.* File No.: 1400669.320 Project No.: 1400669 CALCULATION PACKAGE Quality Program: ~ Nuclear D Commercial PROJECT NAME: Palisades Flaw Readiness Program for lR24 NDE Inspections CONTRACT NO.: 10426669 CLIENT: PLANT: Entergy Nuclear Operations, Inc. Palisades Nuclear Plant CALCULATION TITLE: Finite Element Model Development for the Cold Leg Drain, Spray, and Charging Nozzles Project Manager Preparer(s) & Document Affected Revision Description Approval Cbecker(s) Revision Pages Signature & Date Signatures & Date o 1 - 20 Initial Issue Preparer: A-I - A-2 Computer Files ;t~~..~_ IJJ~ ~ Norman Eng NE 4/3/15

                                                                                           .  ~

WIlson Wong WW 4/3/15 Checker: Charles Fourcade CJF 4/3/15 Gole Mukhim GSM 4/3/15 Page 1 of20 F0306-01Rl

Table of Contents 1.0 OBJECTIVE .................................................................................................................. 4 2.0 TECHNICAL APPROACH .......................................................................................... 4 3.0 ASSUMPTIONS / DESIGN INPUTS .......................................................................... .4 4.0 FINITE ELEMENT MODEL ........................................................................................ 5 4.1 Element Type and Mesh .................................................................................... 5 4.2 Materials ............................................................................................................ 5 4.2.1 Creep Properties ........... .. ................................................................................... 5 4.3 Loads and Boundary Conditions ....................................................................... 6

5.0 CONCLUSION

S ........................................................................................................... 6

6.0 REFERENCES

.............................................................................................................. 7 APPENDIX A COMPUTER FILES LISTING .................................................................... A-I File No.: 1400669.320                                                                                                                  Page 2 of20 Revision: 0 F0306-01R2

List of Tables Table 1: Component Materials ................................................................................................. 8 Table 2: Elastic Properties for SA-516 Grade 70 (~ 4" Thick) ................................................ 9 Table 3: Stress-Strain Curves for SA-516 Grade 70 (~4" Thick) ......................................... 10 Table 4: Elastic Properties for ER308L .................................................................................. 11 Table 5: Stress-Strain Curves for ER308L ............................................................................. 12 Table 6: Elastic Properties for Alloy 600 ............................................................................... 13 Table 7: Stress-Strain Curves for Alloy 600 ........................................................................... 14 Table 8: Elastic Properties for Alloy 82/182 .......................................................................... 15 Table 9: Stress-Strain Curves for Alloy 82/182 ..................................................................... 16 Table 10: Creep Properties ..................................................................................................... 17 List of Figures Figure 1. Finite Element Model Dimensions .......................................................................... 18 Figure 2. Components Included in the Finite Element ModeL .............................................. 19 Figure 3. Isometric View of the Finite Element ModeL ........................................................ 20 File No.: 1400669.320 Page 3 of20 Revision: 0 F0306-01R2

1.0 OBJECTIVE The objective of this calculation package is to docwnent the development of a bounding finite element model for the reactor cold leg spray, drain, and charging nozzles at the Palisades Nuclear Plant, which will be used to perform residual and operational-based fracture mechanics analyses to support a subsequent fracture mechanics evaluation as part of a flaw readiness program. 2.0 TECHNICAL APPROACH One bounding three-dimensional (3-D) finite element model is developed using the ANSYS finite element analysis software package [1] to represent a group of cold leg nozzles. All three nozzles are of similar size near the forging boss area (within 1116 inch) [2, 3, and 4]. Therefore, the largest inside diameter (I D) and smallest outside diameter (OD) of the three nozzles is chosen for the bounding model. The spray and drain nozzles have identical nozzle and boss OD dimensions of 4-9/16 inch and 6-3/16 inch, respectively, which are slightly smaller than the charging nozzle OD dimensions of 4-5/8 inch and 6-114 inch. For the nozzle ID, the charging nozzle is bored out to 2-5/8 inch in the first 1.5 inch to accommodate a thermal sleeve. For conservatism, it is asswned that the entire nozzle ID is 2-5/8 inch. The area of interest is the nozzle-to-pipe weld. The model uses elastic-plastic material properties intended for weld residual stress analysis, and elastic material properties for linear elastic analyses. 3.0 ASSUMPTIONS / DESIGN INPUTS The dimensions and material types to develop the finite element model are provided in References 2, 3, and 4 and summarized in Figure 1. The material properties are obtained from References 5 and 6. A nwnber of asswnptions were made during development of the finite element model, which are listed as follows :

• Since the area of interest is the nozzle to cold leg weld, dimensional differences between nozzles on the attached piping side are considered insignificant.
• The largest inside diameter (I D) and smallest outside diameter (OD) of the three nozzles will be chosen for the bounding model. This is conservative for pressure and mechanical loads.
• The axial length of the modeled portion of the cold leg piping is arbitrarily set at 36 inches, which is sufficiently long to negate possible end effects in the region of interest.
• The ID patch weld is added after removal of the backing ring according to the weld procedure mentioned in the drawings [2, 3]. The same material of the nozzle-to-pipe weld is used for the ID patch weld.

File No.: 1400669.320 Page 4 of20 Revision: 0 F0306-01R2

4.0 FINITE ELEMENT MODEL The model includes a local portion of the cold leg pipe and cladding, the nozzle, and the nozzle-to-pipe weld, including the ID patch weld, as shown in Figure 2. As shown in the figure, a single 90° quadrant of the nozzle penetration is modeled due to geometric symmetry. The included portion of the cold leg piping measures 36 inches longitudinally and 180 degrees circumferentially. The mesh of the finite element model is shown in Figure 3. 4.1 Element Type and Mesh The 8-node solid element (SOLIDI85) in ANSYS [1] is used for the model. SOLID185 elements support material plasticity which is suitable for residual stress and elastic plastic fracture mechanics (EPFM) analyses. The model contains adequate mesh refinement within the weld region to predict the residual stresses from welding. 4.2 Materials The material designation for the modeled components is listed in Table 1. The temperature dependent nonlinear material property values are provided in a separate calculation package [6], which are based on the 2001 Edition of the ASME Code with Addenda through 2003 [5]. The material properties are listed in Table 2 through Table 9. 4.2.1 Creep Properties Since post weld heat treatment (PWHT) will be considered in the subsequent residual stress calculation, creep properties are required. In general, creep becomes significant at temperatures above 800°F; thus, creep behavior under 800°F will not be considered in this analysis. There are two main categories of creep: primary and secondary. The primary creep addresses the creep characteristics for a short duration at the early stages of the creep regime, while the secondary creep accounts for the creep behavior for a long duration - usually more than 10,000 hours. Based on this definition, the PWHT falls within the primary creep characteristics. However, primary creep rates for materials are difficult to obtain, so the conservative secondary creep rates are used since primary creep rate is typically an order of magnitude higher than that for secondary creep. In general, the primary creep rate for the materials is governed by the equation: dE = Au n dt The creep data for the SA-516 Grade 70 cold leg material is based on carbon steel material [7]. The creep data for the Alloy 82/182 and ER308L weld metals are not available, so the creep properties for their base metals are used instead. The creep data for Type 304 (for ER308L) is provided in the same reference document as the carbon steel [7], while the creep data for the Alloy 600 (for Alloy 821182) is provided in a separate reference document [8]. All the creep strengths, cr, are provided at two creep rates [7, 8] for each temperature point. File No.: 1400669.320 Page 5 of20 Revision: 0 F0306-01R2

When creep strength is provided at two creep rates at the same temperature point, as listed in Table 10, then A and n can be calculated as follows, where subscripts 1 and 2 refer to the creep data sets 1 and 2: d& =&* = Au n dt

           &)  =Au)n;  &2 =A0"2 n 4.3        Loads and Boundary Conditions No loads or boundary conditions of any kind are included in the fmite element model in this calculation.

Specific loads and boundary conditions, appropriate to the specific analyses, will be applied in the subsequent residual and thermal/mechanical stress calculation packages.

5.0 CONCLUSION

S A bounding finite element model for the cold leg spray, drain, and charging nozzles is developed. The model will be used in subsequent weld residual stress analyses and fracture mechanics analyses. The necessary ANSYS input file names are listed in Appendix A. File No.: 1400669.320 Page 6 of20 Revision: 0 F0306-01Rl

6.0 REFERENCES

1. ANSYS Mechanical APDL and PrepPost, Release 14.5 (wi Service Pack 1), ANSYS, Inc.,

September 2012.

2. Combustion Engineering Drawing E232-675-4, "Nozzle Details," SI File No. 1400669.202.

3. Combustion Engineering Drawing E232-676-7, Nozzle Details," SI File No. 1400669.202.

4. Combustion Engineering Drawing E232-673-7, "Piping Assembly & Details," SI File No.

1400669.202.

5. ASME Boiler and Pressure Vessel Code, Section II, Part D - Properties, 2001 Edition with Addenda through 2003 .

6. SI Calculation No. 0800777.307, Rev. 5, "Material Properties for Residual Stress Analyses, Including MISO Properties Up To Material Flow Stress."

7. "Steels for Elevated Temperature Service," United States Steel Co., 1949.

8. Publication SMC-027, "Inconel Alloy 600," Special Metals Corp., 2004, SI File 0800777.211.

9. Palisades Design Input Record, "Palisades Alloy 600 Flaw Eval DIR 3-4-15 Rev l.pdf," SI File No. 1400669.201.

File No.: 1400669.320 Page 7 of20 Revision: 0 F0306-01R2

Table 1: Component Materials Component Material References Cold Leg Piping SA-516 Grade 70 [9] Pipe Cladding ER308L (1) [4] SB-166 Bounding Nozzle [2,3] (N06600, Alloy 600)<2) Weld Alloy 182 [9] ID Patch Weld Alloy 182 [9] Notes:

1. The material properties are based on equivalent Type 304 base material.

2. Alloy SB-166 is assumed to have the same material properties as Alloy 600.

File No.: 1400669.320 Page 8 of20 Revision: 0 F0306-01R2

e Bltvcllnl ,,,,.,,,,, Assoclatss. Inc.- Table 2: Elastic Properties for SA-516 Grade 70 (~ 4" Thick) Elastic Mean Thermal Thermal Specific Temperature Conductivity(2) Heat(2) Modulus Expansion eF) (xl03 ksi) (xl0-6 in/in/oF) (Btu/min-in-OF) (Btullb-°F) 70 29.5 6.4 0.0488 0.103 500 27.3 7.3 0.0410 0.128 700 25.5 7.6 0.0369 0.138 1100 18.0 8.2 0.0290 0.171 1500 5.0 8.6 0.0218 0.198 2500 0.1 9.5 0.0014 0.204 2500.1 -- 0 -- -- Notes:

1. All values per [6].

2. Density (p) = 0.283 Ib/in3 [6], assumed temperature independent.

3. Poisson's Ratio (v) = 0.3 [6], assumed temperature independent.

File No.: 1400669.320 Page 9 of20 Revision: 0 F0306-01R2

Table 3: Stress-Strain Curves for SA-516 Grade 70 (~ 4" Thick) Temperature Strain Stress CF) (in/in) (ksi) 0.00128814 38.000 0.00187809 42.000 70 0.00257329 46.000 0.00381110 50.000 0.00600383 54.000 0.00113553 31.000 0.00142679 35.875 500 0.00183954 40.750 0.00261139 45.625 0.00415246 50.500 0.00106667 27.200 0.00132412 32.550 700 0.00166876 37.900 0.00228121 43.250 0.00354341 48.600 0.00116667 21.000 0.05116163 22.125 1100 0.05915444 23.250 0.06794123 24.375 0.07755935 25.500 0.00300000 15.000 0.16717493 15.125 1500 0.16992011 15.250 0.17268761 15.375 0.17547742 15.500 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [6].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.320 Page 10 of20 Revision: 0 F0306-01R2

S)Btntc",,., ""."", Assoclatts, Inc.- Table 4: Elastic Properties for ER308L Elastic Mean Thermal Thermal Specific Temperature Conductivity(2) Heat(2) Modulus Expansion (OF) (xl03 ksi) (xl0-6 in/in/oF) (Btulmin-in-OF) (Btullb-OF) 70 28.3 8.5 0.0119 0.116 500 25.8 9.7 0.0151 0.131 700 24.8 10.0 0.0164 0.135 1100 22.1 10.5 0.0189 0.140 1500 18.1 10.8 0.0212 0.145 2500 0.1 11.5 0.0292 0.159 2500.1 -- 0 -- -- Notes:

1. All values per [6].

2. Density (p) = 0.283 Ib/in3 [6], assumed temperature independent.

3. Poisson's Ratio (v) = 0.3 [6], assumed temperature independent.

File No.: 1400669.320 Page 11 of20 Revision: 0 F0306-01R2

S)BInIc:",,., ,,,,.,,,,, Associatls, Inc.- Table 5: Stress-Strain Curves for ER308L Temperature Strain Stress (OF) (in/in) (ksi) 0.00203180 57.500 0.02471351 61.563 70 0.03107296 65.625 0.03861377 69.688 0.04747167 73.750 0.00140089 36.143 0.00714793 40.250 500 0.01065407 44.357 0.01558289 48.464 0.02233857 52.571 0.00132488 32.857 0.00477547 37.125 700 0.00743595 41.393 0.01143777 45.661 0.01727192 49.929 0.00121913 26.943 0.00264833 30.138 1100 0.00404100 33.332 0.00634529 36.527 0.01005286 39.721 0.00117995 21.357 0.05352064 21.563 1500 0.05610492 21.768 0.05878975 21.973 0.06157807 22.179 0.01000000 1.000 0.10961239 1.125 2500 (2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [6].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.320 Page 12 of20 Revision: 0 F0306*01R2

Table 6: Elastic Properties for Alloy 600 Elastic Mean Thermal Thermal Specific Temperature Heat(2) Modulus Expansion Conductivity(2) eF) (xl03 ksi) (xlO-6 in/in/oF) (Btu/lb-OF) (Btu/min-in-OF) 70 31.0 6.8 0.0119 0.108 500 29.0 7.6 0.0147 0.120 700 28.2 7.9 0.0161 0.125 1100 25.9 8.4 0.0192 0.139 1500 23.1 9.0 0.0222 0.148 2500 0.1 10.0 0.0306 0.177 2500.1 -- 0 -- -- Notes:

1. All values per [6].

2. Density (p) = 0.300 Ib/in3 [6], assumed temperature independent.

3. Poisson's Ratio (v) = 0.29 [6], assumed temperature independent.

File No.: 1400669.320 Page 13 of20 Revision: 0 F0306-01R2

S)8Intclrnl ,,,,.,,,,, Assoclatss, Inc.- Table 7: Stress-Strain Curves for Alloy 600 Temperature Strain Stress (OF) (in/in) (ksi) 0.00157419 48.800 0.01658847 55.300 70 0.02343324 61.800 0.03212188 68.300 0.04291703 74.800 0.00152069 44.100 0.01539220 50.338 500 0.02210610 56.575 0.03072476 62.813 0.04153277 69.050 0.00152128 42.900 0.01634485 49.000 700 0.02334760 55.100 0.03227153 61.200 0.04338643 67.300 0.00155985 40.400 0.02275193 44.475 1100 0.03004563 48.550 0.03888203 52.625 0.04943592 56.700 0.00092641 21.400 0.08827666 22.475 1500 0.09785101 23.550 0.10796967 24.625 0.11863796 25.700 0.01000000 1.000 0.10961239 1.125 2500 (2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [6].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.320 Page 14 of20 Revision: 0 F0306-01R2

Table 8: Elastic Properties for Alloy 82/182 Elastic Mean Thermal Thermal Specific Temperature Conductivity (2) Heat (2) Modulus Expansion (OF) (xl03 ksi) (xl0-6 in/in/oF) (Btulmin-in-OF) (Btu/lb-OF) 70 31.0 6.8 0.0119 0.108 500 29.0 7.6 0.0147 0.120 700 28.2 7.9 0.0161 0.125 1100 25.9 8.4 0.0192 0.139 1500 23.1 9.0 0.0222 0.148 2500 0.1 10.0 0.0306 0.177 2500.1 - 0.0 - - Notes:

1. All values per [6].

2. Density (p) = 0.300 Ib/in3 [6], assumed temperature independent.

3. Poisson's Ratio (v) = 0.29 [6], assumed temperature independent.

File No.: 1400669.320 Page 15 of20 Revision: 0 F0306-01R2

Table 9: Stress-Strain Curves for Alloy 82/182 Temperature Strain Stress CF) (in/in) (ksi) 0.00179032 55.500 0.03456710 60.113 70 0.04292837 64.725 0.05257245 69.338 0.06359421 73.950 0.00164483 47.700 0.02976152 52.313 500 0.03809895 56.925 0.04790379 61.538 0.05929946 66.150 0.00159574 45.000 0.02849157 49.538 700 0.03680454 54.075 0.04663682 58.613 0.05812078 63.150 0.00159073 41.200 0.03568855 44.488 1100 0.04402702 47.775 0.05360088 51.063 0.06449835 54.350 0.00106494 24.600 0.11812735 25.325 1500 0.12540227 26.050 0.13290814 26.775 0.14064577 27.500 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [6].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.320 Page 16 of20 Revision: 0 F0306-01R2

e Slntc",,., "."", Associates. Inc.- Table 10: Creep Properties Creep Strength (ksi) Temperature A Material (JI (J2 n (OF) (ksilhr) (0.0001 %/hr) (0.00001 %/hr) SA-516 Gr. 800 19.0 12.4 1.26E-13 5.40 70 900 9.0 6.7 3.59E-14 7.80 (Based on 1000 3.5 2.8 2.43E-12 10.32 carbon steel 1100 1.4 0.8 2.50E-07 4.11 per [7]) ER308L 800 33.4 25.0 7.73E-19 7.95 900 24.0 17.6 5.67E-17 7.42 (Based on Type 304 1000 17.6 11 .5 1.82E-13 5.41 per [7]) 1100 11 .5 7.1 8.62E-12 4.77 Alloy 600 800 40.0 30.0 1.50E-19 8.00 Alloy 82/182 900 28.0 18.0 2.87E-14 5.21 (Based on 1000 12.5 6.1 3.02E-1O 3.21 Alloy 600 1100 6.8 3.4 1.72E-09 3.32 per [8]) File No.: 1400669.320 Page 17 of20 Revision: 0 F0306-01R2

2 5/S" 1.0. 4 9116" 0.0. 36" From Center Line 65/S" Figure 1. Finite Element Model Dimensions Note: Dimensions obtained from [2,3, and 4]. File No.: 1400669.320 Page 18 of20 Revision: 0 F0306-01R2

Cold Leg Pipe Nozzle Forging Nozzle Boss Weld ID Patch Weld Figure 2. Components Included in the Finite Element Model File No.: 1400669.320 Page 19 of20 Revision: 0 F0306-01R2

S;BIntcIu,., ""."", Associates. Inc.- Figure 3. Isometric View of the Finite Element Model (Nozzle detail shown in bottom left comer) File No.: 1400669.320 Page 20 of20 Revision: 0 F0306-01R2

APPENDIX A COMPUTER FILES LISTING File No.: 1400669.320 Page A-I of A-2 Revision: 0 F0306-01R2

FileName Description Palisades CL.INP Input file to create base model geometry MProp_ Miso.INP Elastic plastic material properties inputs Excel spreadsheet containing calculations of elastic-plastic MatProp.xls material properties for residual stress analysis File No.: 1400669.320 Page A-2 of A-2 Revision: 0 F0306-01R2

lJ Slmcturallntegrlty Associates, Inc.* File No.: 1400669.322 Project No.: 1400669 CALCULATION PACKAGE Quality Program: [8J Nuclear 0 Commercial PROJECT NAME: Palisades Flaw Readiness Program for lR24 NDE Inspection CONTRACT NO.: 10426669 CLIENT: PLANT: Entergy Nuclear Operations, Inc. Palisades Nuclear Plant CALCULATION TITLE: Cold Leg Bounding Nozzle Weld Residual Stress Analysis Project Manager Preparer(s) & Document Affected Revision Description Approval Cbecker(s) Revision Pages Si2nature & Date Si2natures & Date o 1 - 38 Initial Issue Preparer: A-I - A-2 Computer Files ~~_ tJJ~W~ Norman Eng Wilson Wong NE 5/5/2015 WW 5/512015 Checkers: Minji Fong MF 5/5/2015 GoleMukhim GSM 5/5/2015 Page 1 of38 F0306-01RI

Table of Contents 1.0 OBJECTIVE .................................................................................................................. 5 2.0 TECHNICAL APPROACH .......................................................................................... 5 2.1 Material Properties ............................................................................................. 5 2.2 Finite Element Model for Weld Residual Stress Analysis ................................ 5 2.3 Welding Simulation ........................................................................................... 6 2.4 Heat Inputs ......................................................................................................... 6 2.5 Creep Properties ................................................................................................. 7 2.6 Mechanical Boundary Conditions ..................................................................... 7 3.0 ASSUMPTIONS ............................................................................................................ 7 4.0 WELD RESIDUAL STRESS ANALYSIS ................................................................... 8 4.1 Cold leg Cladding .............................................................................................. 8 4.2 Boss Weld .......................................................................................................... 8 4.3 ID Patch Weld .................................................................................................... 9 4.4 Post-weld Heat Treatment ................................................................................. 9 4.5 Hydrostatic Test ................................................................................................. 9 4.6 Five Normal Operating Cycles (NOC) ............................................................ 10 5.0 RESULTS OF WELD RESIDUAL STRESS ANAL YSIS ......................................... lO 5.1 Welding Temperature Contours ...................................................................... 10 5.2 PWHT Temperature Results ............................................................................ 10 5.3 Residual Stress Results .................................................................................... 11

6.0 CONCLUSION

S .............. ........................................................................................... 11

7.0 REFERENCES

............................................................................................................ 12 APPENDIX A COMPUTER FILES LISTING .................................................................... A-I File No.: 1400669.322                                                                                                                  Page 2 of38 Revision: 0 F0306-01Rl

List of Tables Table 1: Elastic Properties for SA-516 Grade 70 (~4" Thick) ............................................... 13 Table 2: Elastic Properties for ER308L .................................................................................. 14 Table 3: Elastic Properties for Alloy 600 ............................................................................... 15 Table 4: Elastic Properties for Alloy 82/182 .......................................................................... 16 Table 5: Stress-Strain Curves for SA-516 Grade 70 (~4" Thick) .......................................... 17 Table 6: Stress-Strain Curves for ER308L ............................................................................. 18 Table 7: Stress-Strain Curves for Alloy 600 ........................................................................... 19 Table 8: Stress-Strain Curves for Alloy 82/182 .....................................................................20 Table 9: Creep Properties ....................................................................................................... 21 File No.: 1400669.322 Page 3 of38 Revision: 0 F0306-01Rl

e llnlclrnll"" ' Associates, Inc.- List of Figures Figure 1: Finite Element Model for Residual Stress Analysis ............................................... 22 Figure 2: Applied Mechanical Boundary Conditions ............................................................. 23 Figure 3: Weld Nugget Definitions for the Boss Weld .......................................................... 24 Figure 4: Weld Nugget Definitions for the ID Patch Weld .................................................... 25 Figure 5: Applied Hydrostatic Test Pressure and Corresponding End Cap Pressure Loads .. 26 Figure 6: Predicted Fusion Boundary Plot for Cladding ........................................................ 27 Figure 7: Predicted Fusion Boundary Plot for Boss Weld ..................................................... 28 Figure 8: Predicted Fusion Boundary Plot for ID Patch Weld ............................................... 29 Figure 9: Time vs. Temperature Curve for PWHT................................................................. 30 Figure 10: Predicted von Mises Residual Stress at 70°F after ID Patch Weld ....................... 31 Figure 11: Predicted von Mises Residual Stress at 70°F after PWHT ................................... 32 Figure 12: Paths for Stress Extraction .................................................................................... 33 Figure 13: Residual Stress Comparison at 70°F Before and After PWHT ............................. 34 Figure 14: Measured Through-Wall Residual Stresses for PWHT ........................................ 35 Figure 15: Predicted von Mises Residual Stress at 70°F after Hydrostatic Test.. .................. 36 Figure 16: Predicted Radial Residual Stress + Operating Conditions (5 th NOC Cycle) ........ 37 Figure 17: Predicted Hoop Residual Stress + Operating Conditions (5 th NOC Cycle) .......... 38 File No.: 1400669.322 Page 4 of38 Revision: 0 F0306-01RI

1.0 OBJECTIVE The objective of this calculation package is to document the weld residual stress analysis for the bounding cold leg nozzle at the Palisades Nuclear Plant (Palisades). The bounding nozzle bounds the spray, drain, and charging nozzles discussed in a separate calculation package [1]. The weld residual stress analysis is based on the latest methodology and process developed by Structural Integrity Associates (SI). 2.0 TECHNICAL APPROACH The finite element model is obtained from a previous finite element model (FEM) calculation package [1] and the weld residual stress analysis uses the latest weld residual stress analysis methodology developed by SI, using the ANSYS finite element analysis (FEA) program [3]. The residual stress analysis consists of a thermal pass followed by a stress pass where the temperature distribution time history from the thermal pass is used as temperature input into the stress pass to determine stresses. Stress results from the weld residual stress analysis are obtained and saved for future use to evaluate flaws which will be performed in a separate calculation package. The finite element model includes all components in the post-nozzle installation stage because new elements cannot be added during an ANSYS analysis. Since all the weld elements need to be included in the initial model, the element "birth and death" technique in ANSYS is used to initially deactivate the weld elements, with elements corresponding to the active weld segment reactivated at the melting temperature, thus simulating the weld metal deposition. 2.1 Material Properties The weld residual stress analysis performed in this calculation uses the material properties specifically developed in a separate calculation package for weld residual stress analyses [2]. Per the material designation used in the FEM calculation [1], the following materials are used:

• SA-516 Grade 70: Cold leg base metal
• ER308L: Cold leg cladding (typical weld metal for Type 304)
• Alloy 82/182: Boss weld and ID patch weld
• Alloy 600 (SB-166): Nozzle The material properties are reproduced in Table 1 through Table 8.

2.2 Finite Element Model for Weld Residual Stress Analysis The finite element model for the analysis was developed in a previous FEM calculation [1], which was created using the ANSYS finite element analysis software package [3]. The base finite element model File No.: 1400669.322 Page 5 of38 Revision: 0 F0306-01Rl

for the weld residual stress analysis is meshed with 8-node solid elements (SOLID 185) in ANSYS. This finite element model is shown in Figure 1. 2.3 Welding Simulation The FEA for predicting the weld residual stresses is performed as a continuous analysis so that the load history from the cladding is carried over to the nozzle-to-pipe weld and the ID patch weld. Specifically, the residual stresses and strains at the end of a weld pass are used as initial conditions at the start of the next weld pass. The procedures for this complex multi-step simulation are encoded in ANSYS Parametric Design Language (APDL) macros which utilize elastic-plastic material behavior and elements with large deformation capability to predict the residual stresses due to the various welding processes. 2.4 Heat Inputs The deposition of the weld metal is simulated by imposing a heat generation function on the elements of the FEM representing the active weld, which is applied as a volumetric body heat generation rate. The amount of equivalent heat input energy, Q (in terms ofkJ/inch), is determined from the welding parameters. Since the welding parameters for the welds are not available, a typical heat input of 28 kJ/inch, with an overall heat efficiency of 0.8, is assumed for all the welds. The heat efficiency represents a "composite" value reflecting the concepts of arc efficiency, melting efficiency, etc., and is an optimum value to produce reasonable heat penetration in the analysis. The APDL macros automatically calculate the appropriate time intervals for the thermal pass to ensure that sufficient heat penetration is achieved, the required interpass temperature between weld passes is met, and a reasonable overall temperature distribution within the finite element model is achieved. The resulting temperature time history is then imported into the stress pass in order to calculate the residual stresses due to the thermal cycling of the weld elements using nonlinear, elastic-plastic load/unload stress reversal relations. The following summarizes the welding parameters used in the analysis:

• Interpass temperature = 350°F [4]
• Melting temperature = 2500°F (See Section 3.0)
• Reference temperature = 70°F (See Section 3.0)
• Heat input for all welds 28 kJ/in (See Section 3.0)
• Heat efficiency for all welds = 0.8 (See Section 3.0)
• Inside/Outside heat transfer coefficient = 5 Btu/hr-ft2_oF (See Section 3.0)
• Inside/Outside temperature = 70°F (See Section 3.0)

File No.: 1400669.322 Page 6 of 38 Revision: 0 F0306-01RI

2.5 Creep Properties Strain relaxation due to creep at high temperature is considered in the post-weld heat treatment (PWHT) step of the analysis. In general, creep becomes significant at temperatures above 800°F; thus, creep behavior under 800°F will not be considered in this analysis. The creep properties listed in Table 9 are determined in the previous FEM calculation [1]. 2.6 Mechanical Boundary Conditions The mechanical boundary conditions for the stress analysis are symmetric boundary conditions at the symmetry planes of the model, axial displacement restraint at the end of the nozzle, and axial displacement coupling at the end of the cold leg piping, as shown in Figure 2. 3.0 ASSUMPTIONS The following assumptions are used in the analyses:

• The cold leg cladding material is assumed to be ER308L, which is a typical weld metal for Type 304 stainless steel cladding.
• The metal melting temperature is assumed to be 2500°F, which is the temperature point where the strength of the material is set to near zero [2].
• The analysis is performed with a reference temperature of 70°F.
• The exposed surface of the model is subject to a typical ambient air cooling convection film coefficient of 5 Btulhr-ft2_oF at a bulk temperature of 70°F. The exposed surfaces are defined as the exterior surfaces of the model excluding the symmetry planes and the far ends of the modeled piping and nozzle.
• Since the welding parameters for the welds are not available, a typical heat input of 28 kJ/in, with an overall heat efficiency of 0.8, is assumed for all of the welds.
• The focus of this analysis is the residual stresses in the nozzle boss weld region, while the interaction between the clad buildup and the cold leg base metal has secondary effects on the region of interest. Therefore, the clad is assumed to be fully deposited in a single one-layer pass.
• The boss weld is represented by a 40-bead process, as shown in Figure 3, with each bead represented by a one pass "bead ring" nugget. This approach is a common and acceptable industry practice when information regarding the bead start/stop position and sequencing are unknown.
• Similarly, the ID patch weld is represented by a 6-bead process, as shown in Figure 4, with each bead represented by a one pass "bead ring" nugget.
• For model simplification, the penetration hole is present during the deposition of the clad material. This is acceptable since any localized stress with or without the hole would have negligible impact on the final results.

File No.: 1400669.322 Page 7 of38 Revision: 0 F0306-01Rl

• For convenience, the modeled ID patch weld has the same geometry as the backing ring for the boss weld.
• Additional assumptions on PWHT are discussed in Section 4.4.

4.0 WELD RESIDUAL STRESS ANALYSIS The weld residual stress analysis consists of a thermal analysis to determine the temperature distribution followed by a stress analysis to determine the resulting stresses. The analytical sequence described below is used in the finite element analysis, followed by detailed discussions of the steps in Sections 4.1 through 4.6:

1. Deposit cladding on cold leg pipe inside (lD) surface.

2. Install nozzle, backing ring, and deposit boss weld.

3. Remove backing ring and deposit ID patch weld.

4. Post-weld heat treatment, including creep effects based upon experimental data per Table 9.

5. Subject the configuration to a hydrostatic test.

6. Impose five cycles of "shake down" with normal operating temperature and pressure to stabilize the residual stress fluctuations due to stress redistribution caused by normal operating loads.

4.1 Cold leg Cladding The clad material is typically welded onto the inside surface of the cold leg pipe, and the nominal thickness of the clad is thicker than the typical thickness for a single weld layer used in the process. However, the focus of this analysis is on the as-welded residual stresses, while the interaction between the clad buildup and the base material during the many actual weld passes is not of interest. Therefore, the clad is assumed to be fully deposited in a single pass. At this step, only the cold leg pipe base metal elements and clad material elements are active; all other components are deactivated during the analysis. At the end of the cladding application, the entire model is cooled to 70°F before the application of the boss weld. 4.2 Boss Weld The boss weld connects the nozzle boss to the cold leg piping. As shown in Figure 3, the weld is composed of 40 nuggets deposited in 20 weld layers. In the absence of detailed weld fabrication information, a weld sequence is assumed based on standard welding practice at the time of fabrication. In particular, for every layer, the first nugget is deposited on the cold leg side, the second nugget on the nozzle side. File No.: 1400669.322 Page 8 of38 Revision: 0 F0306-01RI

At this step, the nozzle elements and backing ring elements are reactivated, and the boss weld nuggets are reactivated sequentially to simulate the welding process. The preheat temperature of the boss weld is 250°F [4]. At the end of the boss weld, the entire model is cooled to 70°F before the application of the ID patch weld. 4.3 ID Patch Weld The final weld step is to add the ID patch weld, which replaces the backing ring. As seen in Figure 4, the ID patch weld is composed of 6 nuggets deposited in 2 layers. At this step, the backing ring is first deactivated to allow the residual stresses to redistribute, and the ID patch weld nuggets are reactivated sequentially to simulate the welding process. The preheat temperature of the ID patch weld is 250°F [4]. At the end of the ID patch weld, the entire model is cooled to 70°F before the application of the PWHT. 4.4 Post-weld Heat Treatment PWHT is assumed to be performed as per the following procedure outlined in Article N-532 of the ASME Code, Section III [7] and the welding procedure [4] for welding on material group P-1 :

1. Heat welded piping component to 1150°F at a heating rate of 400°F per hour divided by the maximum metal thickness (133° per hour for 3 inch thick cold leg) [7, Article N-532.3 (2)].

2. Hold at temperature for approximately 3 hours (lhr/in of weld thickness) [7, Table N-532.3] .

3. Allow to cool to 600°F at a cooling rate of 500°F per hour divided by the maximum metal thickness (167° per hour for 3 inch thick cold leg) at temperatures above 600°F [7, Article N-532.3 (5)].

4. Air-cool from 600°F to ambient [7, Article N-532.3 (5)].

5. A steady state load step is imposed at the end of the PWHT process.

During the PWHT, creep behavior is activated for time steps with the maximum temperature above 800°F. At the end of the PWHT, the entire model is cooled 70°F before the application of the hydrostatic test. 4.5 Hydrostatic Test A hydrostatic test pressure of 311 0 psig (3125 psia) and a temperature of 400°F [8, page 9] are applied after the welding. The pressure is applied on the ID surfaces of the cold leg pipe and nozzle. An end-cap load, Pend-cap-cl, is applied at the free end of the cold leg piping. This is calculated based on the following expression: Pend-cap-c1 = - r -P . r imide _ c/ 2

                                  - -:2 : - - - - : : -2 t =

rOlllSlde _ c/ - r illSide _ d File No.: 1400669.322 Page 9 of38 Revision: 0 F0306-01RI

where, P = Hydrostatic test pressure (ksi) Pend-cap-c1 = End cap pressure on cold leg pipe end (ksi) finside31 = Inside radius of cold leg pipe (in) routside_cl = Outside radius of cold leg pipe (in) The applied pressure loads on the model are shown in Figure 5. 4.6 Five Normal Operating Cycles (NOC) After the hydrostatic test, the assembled configuration is put into service and subjected to 5 cycles of shake down to stabilize the as-welded residual stresses. This step involves simultaneously ramping the model from zero-load to steady-state conditions at normal operating temperature and pressure then back to steady-state at 70°F and no pressure five times. The applied operating pressure and temperature is 2085 psig (2100 psia) and 537°F [9]. The temperature is assumed to be uniform throughout the components and operating pressure is applied as an internal pressure on the ID surface, with corresponding end-cap pressure calculated using the equation in the previous section. The term "P" is replaced by the operating pressure in the expression. 5.0 RESULTS OF WELD RESIDUAL STRESS ANALYSIS The ANSYS input files and computer output files for the analyses are listed in Appendix A. 5.1 Welding Temperature Contours The maximum temperature prediction contours for each weld are created using macro MapTemp.mac. This type of contour plot is also called a "fusion boundary" plot because it provides an overview of the maximum temperature on each node throughout the thermal transient for each welding process. The plots are useful in visualizing the melting of weld metal and the extent of heat penetration. The predicted fusion boundary contours for the cladding, boss weld, and ID patch weld are shown in Figure 6, Figure 7, and Figure 8, respectively. The purple color in the plots represents elements at melting temperature (>2500°F); the plots show complete melting of the weld metal for each weld and slight melting of the base metal along the weld interface. 5.2 PWHT Temperature Results Figure 9 plots the inside surface temperature curve for the PWHT process. It shows the linear 133°Flhour heating rate, three hours (180 minutes) hold time at 1150°F, 167°Flhour cooling rate at temperature above 600°F, and the air cooling to room temperature of 70°F. File No. : 1400669.322 Page 10 of38 Revision: 0 F0306-01Rl

5.3 Residual Stress Results Figure 10 plots the von Mises residual stresses after welding is complete, but before PWHT. It shows extensive residual stresses of greater than 66 ksi in the weld material. However, as shown in Figure 11 , after the PWHT the residual stresses in the weld have relaxed significantly, to below 41 ksi, but the residual stresses in the cladding remain essentially unchanged. To further investigate the effects of the PWHT, before and after PWHT residual stresses are extracted along the two through-wall paths shown in Figure 12. The through-wall residual stresses are compared in Figure 13, and it shows that there is little to no stress reduction in the clad material, while there is significant stress reduction in the pipe base metal. The PWHT results from the FEA trend comparably well with the data in EPRI report TR-105697 [10], which contains a comparable through-wall clad residual stress distribution based on experimental measurements, as shown in Figure 14. The experimental measurements were for a low alloy steel vessel with a Type 304 stainless steel clad. The data shows tensile hoop stress through the clad thickness and the base metal near the clad interface, but the hoop stress drops rapidly to compressive values at farther distances from the clad. Figure 15 depicts the predicted von Mises residual stresses after the hydrostatic test. It shows an insignificant reduction in maximum stress when compared to the post-PWHT step: 73 .74 ksi (Figure 15) versus 73.75 ksi (Figure 11), while the overall stress contour remains essentially the same. Figure 16 and Figure 17 depicts the combined weld residual plus operating radial and hoop stresses, respectively, at the fifth stabilization NOC cycle. The stress results at this step are used in the fracture mechanics evaluations.

6.0 CONCLUSION

S Finite element residual stress analysis has been performed on the bounding cold leg nozzle boss weld at Palisades. Stresses at normal operating conditions combined with residual stresses have been obtained and saved for future use. The stress results will be used in a separate calculation to determine crack growth. File No.: 1400669.322 Page 11 of38 Revision: 0 F0306-01Rl

7.0 REFERENCES

1. SI Calculation No. 1400669.320, Rev. 0, "Finite Element Model Development for the Cold Leg Drain, Spray, and Charging Nozzles."

2. SI Calculation No. 0800777.307, Rev. 5, "Material Properties for Residual Stress Analyses, Including MISO Properties Up To Material Flow Stress."

3. ANSYS Mechanical APDL and PrepPost, Release 14.5 (wi Service Pack 1), ANSYS, Inc.,

September 2012.

4. Combustion Engineering Welding Procedure No. MA-41 , Rev.O, SI File No. 1400669.204.

5. "Steels for Elevated Temperature Service," United States Steel Co., 1949.

6. Publication SMC-027, "Inconel Alloy 600," Special Metals Corp., 2004, SI File 0800777.211.

7. ASME Boiler and Pressure Vessel Code, Section III, 1965 Edition with Addenda through Winter 1966.

8. Combustion Engineering Specification No. 0070P-006, Rev. 2, "Engineering Specification for Primary Coolant Pipe and Fittings," SI File No. 1300086.203.

9. Palisades Design Input Record, "Palisades Alloy 600 Flaw Eval DIR 3-4-15 Rev1.pdf," SI File No. 1400669.201.

10. EPRI Report No. TR-105697, "BWR Reactor Pressure Vessel Shell Weld Inspection Recommendations (BWRVIP-05)," September 1995.

File No.: 1400669.322 Page 12 of38 Revision: 0 F0306-01RI

Table I: Elastic Properties for SA-516 Grade 70 (:::4" Thick) Young's Mean Thermal Thermal Temperature Specific Heat (2) Modulus Expansion Conductivity (2) eF) (Btullb-OF) (xlOl ksi) (xI0-6 in/in/OF) (Btulmin-in-OF) 70 29.5 6.4 0.0488 0.103 500 27.3 7.3 0.0410 0.128 700 25.5 7.6 0.0369 0.138 1100 18.0 8.2 0.0290 0.171 1500 5.0 8.6 0.0218 0.198 2500 0.1 9.5 0.0014 0.204 2500.1 - 0.0 - - Notes:

1. All values per [2].

2. Density (p) = 0.283 Ib/in3 [2], assumed temperature independent.

3. Poisson's Ratio (u) = 0.3 [2], assumed temperature independent.

File No.: 1400669.322 Page 13 of38 Revision: 0 F0306-01Rl

Table 2: Elastic Properties for ER308L Young's Mean Thermal Thermal Specific Heat (2) Temperature Modulus Expansion Conductivity (2) (OF) (Btu/lb-OF) (xl03 ksi) (xl0-6 in/in/OF) (Btnlmin-in-OF) 70 28.3 8.5 0.0119 0.116 500 25.8 9.7 0.0151 0.131 700 24.8 10.0 0.0164 0.135 1100 22.1 10.5 0.0189 0.140 1500 18.1 10.8 0.0213 0.145 2500 0.1 11 .5 0.0292 0.159 2500.1 - 0.0 - - Notes:

1. All values per [2].

2. Density (p) = 0.283 Ib/in3 [2], assumed temperature independent.

3. Poisson' s Ratio (u) = 0.3 [2], assumed temperature independent.

File No.: 1400669.322 Page 14 of38 Revision: 0 F0306-01Rl

Table 3: Elastic Properties for Alloy 600 Young's Mean Thermal Thermal Temperature Specific Heat (2) Modulus Expansion Conductivity (2) (OF) (BtuIlb-OF) (xl03 ksi) (dO-6 inlinfOF) (Btulmin-in-OF) 70 31.0 6.8 0.0119 0.108 500 29.0 7.6 0.0147 0.120 700 28.2 7.9 0.0161 0.125 1100 25 .9 8.4 0.0192 0.139 1500 23 .1 9.0 0.0222 0.148 2500 0.1 10.0 0.0306 0.177 2500.1 - 0.0 - - Notes:

1. All values per [2].

2. Density (p) = 0.300 lb/in3 [2], assumed temperature independent.

3. Poisson's Ratio (u) = 0.29 [2], assumed temperature independent.

File No.: 1400669.322 Page 15 of38 Revision: 0 F0306-01Rl

Table 4: Elastic Properties for Alloy 82/182 Young's Mean Thermal Thermal Temperature Specific Heat (2) Modulus Expansion Conductivity (2) eF) (Btullb-OF) (xl03 ksi) (xlO-6 in/in/OF) (Btulmin-in-OF) 70 31.0 6.8 0.0119 0.108 500 29.0 7.6 0.0147 0.120 700 28.2 7.9 0.0161 0.125 1100 25.9 8.4 0.0192 0.139 1500 23.1 9.0 0.0222 0.148 2500 0.1 10.0 0.0306 0.177 2500.1 - 0.0 - - Notes:

1. All values per [2].

2. Density (p) = 0.300 Ib/in3 [2], assumed temperature independent.

3. Poisson' s Ratio (u) = 0.29 [2], assumed temperature independent.

File No.: 1400669.322 Page 16 of38 Revision: 0 F0306-01RI

e Duc:IInI """"" Associates, Inc.- Table 5: Stress-Strain Curves for SA-516 Grade 70 (~4" Thick) Temperature Strain Stress CF) (in/in) (ksi) 0.00128814 38.000 0.00187809 42.000 70 0.00257329 46.000 0.00381110 50.000 0.00600383 54.000 0.00113553 31.000 0.00142679 35.875 500 0.00183954 40.750 0.00261139 45.625 0.00415246 50.500 0.00106667 27.200 0.00132412 32.550 700 0.00166876 37.900 0.00228121 43.250 0.00354341 48.600 0.00116667 21.000 0.05116163 22.125 1100 0.05915444 23.250 0.06794123 24.375 0.07755935 25.500 0.00300000 15.000 0.16717493 15.125 1500 0.16992011 15.250 0.17268761 15.375 0.17547742 15.500 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [2].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.322 Page 17 of38 Revision: 0 F0306-01RI

Table 6: Stress-Strain Curves for ER308L Temperature Strain Stress CF) (in/in) (ksi) 0.00203180 57.500 0.02471351 61.563 70 0.03107296 65.625 0.03861377 69.688 0.04747167 73 .750 0.00140089 36.143 0.00714793 40.250 500 0.01065407 44.357 0.01558289 48.464 0.02233857 52.571 0.00132488 32.857 0.00477547 37.125 700 0.00743595 41.393 O.oI 143777 45.661 0.01727192 49.929 0.00121913 26.943 0.00264833 30.138 1100 0.00404100 33.332 0.00634529 36.527 0.01005286 39.721 0.00117995 21.357 0.05352064 21.563 1500 0.05610492 21.768 0.05878975 21.973 0.06157807 22.179 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [2].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.322 Page 18 of38 Revision: 0 F0306-01RI

Table 7: Stress-Strain Curves for Alloy 600 Temperature Strain Stress CF) (in/in) (ksi) 0.00157419 48.800 0.01658847 55.300 70 0.02343324 61.800 0.03212188 68.300 0.04291703 74.800 0.00152069 44.100 0.01539220 50.338 500 0.02210610 56.575 0.03072476 62.813 0.04153277 69.050 0.00152128 42.900 0.01634485 49.000 700 0.02334760 55.100 0.03227153 61.200 0.04338643 67.300 0.00155985 40.400 0.02275193 44.475 1100 0.03004563 48.550 0.03888203 52.625 0.04943592 56.700 0.00092641 21.400 0.08827666 22.475 1500 0.09785101 23.550 0.10796967 24.625 0.11863796 25.700 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [2].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No.: 1400669.322 Page 19 of38 Revision: 0 F0306-01Rl

Table 8: Stress-Strain Curves for Alloy 82/182 Temperature Strain Stress CF) (in/in) (ksi) 0.00179032 55.500 0.03456710 60.113 70 0.04292837 64.725 0.05257245 69.338 0.06359421 73.950 0.00164483 47.700 0.02976152 52.313 500 0.03809895 56.925 0.04790379 61.538 0.05929946 66.150 0.00159574 45.000 0.02849157 49.538 700 0.03680454 54.075 0.04663682 58.613 0.05812078 63.150 0.00159073 41.200 0.03568855 44.488 1100 0.04402702 47.775 0.05360088 51.063 0.06449835 54.350 0.00106494 24.600 0.11812735 25.325 1500 0.12540227 26.050 0.13290814 26.775 0.14064577 27.500 0.01000000 1.000 0.10961239 1.125 2500(2) 0.12781277 1.250 0.14689940 1.375 0.16683167 1.500 Notes:

1. All values per [2].

2. Values at 2500°F assumed arbitrarily small values for convergence stability.

File No. : 1400669.322 Page 20 of38 Revision: 0 F0306-01Rl

Table 9: Creep Properties Temperature Creep Strength (ksi) A Material n (OF) 0'1 (0.0001 %/hr) 0'2 (0.00001 %/hr) (ksilhr) 800 19.0 12.4 1.26E-13 5.40 SA-516 Gr. 70 900 9.0 6.7 3.59E-14 7.80 (Based on carbon steel) 1000 3.5 2.8 2.43E-12 10.32 Per [5] 1100 1.4 0.8 2.50E-07 4.11 800 33.4 25.0 7.73E-19 7.95 ER308L 900 24.0 17.6 5.67E-17 7.42 (Based on Type 304) 1000 17.6 11.5 1.82E-13 5.41 Per [5] 1100 11.5 7.1 8.62E-12 4.77 Alloy 600 800 40.0 30.0 1.50E-19 8.00 Alloy 82/182 900 28.0 18.0 2.87E-14 5.21 (Based on 1000 12.5 6.1 3.02E-I0 3.21 Alloy 600) Per [6] 1100 6.8 3.4 1.72E-09 3.32 File No.: 1400669.322 Page 21 of38 Revision: 0 F0306-01RI

l)BtntcIInI "".", Associates, Inc.- Figure 1: Finite Element Model for Residual Stress Analysis File No.: 1400669.322 Page 22 of38 Revision: 0 F0306-01RI

                                                            ~ Axial displacement
                                                       ~          restraint Axial displacement couples Symmetry boundary conditions Figure 2: Applied Mechanical Boundary Conditions File No.: 1400669.322                                                          Page 23 of38 Revision: 0 F0306-01Rl

Figure 3: Weld Nugget Definitions for the Boss Weld File No.: 1400669.322 Page 24 of38 Revision: 0 F0306-01Rl

Figure 4: Weld Nugget Definitions for the ID Patch Weld File No.: 1400669.322 Page 25 of38 Revision: 0 F0306-01RI

Cold leg end cap pressure ksi

           -6 . 98787 - 5. 86588 -4 . 7439 - 3. 62191 -2 . 49993 - 1. 37794 - . 255956 . 866029 1. 98801 3. 11 Figure 5: Applied Hydrostatic Test Pressure and Corresponding End Cap Pressure Loads File No.: 1400669.322                                                                                         Page 26 of38 Revision: 0 F0306-01RI

2500 of Figure 6: Predicted Fusion Boundary Plot for Cladding (Note: Purple = Temperature> Melting Temperature of 2500°F) File No.: 1400669.322 Page 27 of38 Revision: 0 F0306*01RI

Figure 7: Predicted Fusion Boundary Plot for Boss Weld (Note: Purple = Temperature> Melting Temperature of2500°F) File No.: 1400669.322 Page 28 of38 Revision: 0 F0306-01Rl

Figure 8: Predicted Fusion Boundary Plot for ID Patch Weld (Note: Purple = Temperature> Melting Temperature of2500°F) File No.: 1400669.322 Page 29 of38 Revision: 0 F0306-01Rl

e l nn:IInI ""."", Associatss, Inc.- 1250 - 1125

                                               -r                                     Cooling to 600 2 F at 1672 F/hr         -1 1000 875-750- -

Tercperatute (F) 625 I 500

                                                                                                         -1 I 375 l

250-125-Heating at 133 2 F/hr

                                                                                                        -j 0

1000 1250 1500 1750 2000 2250 1125 1375 1625 1875 2125 Tirre (min) Figure 9: Time vs. Temperature Curve for PWHT Note:

1. PWHT temperature history is for a typical ID node on the model.

File No.: 1400669.322 Page 30 of38 Revision: 0 F0306-01Rl

e BIrrR:",,., '"",rIIy Assoclatss. Inc.-

    ~roU.l'J'J(N STFJ?-1361 SUB -1 l'lMJi10970 S'fit]ol      (A\,G)

RSYS 0 r.:J.<< .143794

    ~       =, 642893 SMl{   =74 . 657 Figure 10: Predicted von Mises Residual Stress at 70°F after ID Patch Weld File No.: 1400669.322                                                                              Page 31 of38 Revision: 0 F0306-01Rl

I'UlAL rotl.JT!CN STF..P-1402 SUB -1 l'1ME-2CJ8.1 SEt;}l (AVG) RSYS-O [).1){ - . 135409 9-N =. 057248 SMK =73 .75 Figure 11: Predicted von Mises Residual Stress at 70°F after PWHT File No.: 1400669.322 Page 32 of38 Revision: 0 F0306-01RI

Figure 12: Paths for Stress Extraction Notes:

1. In the cold leg coordinates, hoop residual stresses along path PI and axial residual stresses along path P2 are extracted for comparison of before and after PWHT.

2. The before and after PWHT through-wall residual stresses are compared in Figure 13.

File No.: 1400669.322 Page 33 of38 Revision: 0 F0306-01Rl

l)BInIc",m,,,,.,,,,, Associates. Inc.- 80

                                      *: ~                                         + As-Welded (Pl) 70
                                      ** ~ Clad interface                          o PWHT (Pl)
                      ~3
                                    **: x 60 x As-Welded (P2) 50                                                               D. PWHT (P2) 40
                      *                ~!   x
                                **:u
           - 20

• 30 x

           'in
           ~
                      *            **       +

ut ut 10 C1J

                                                 +

V) 0

                                            ~    ~    x 9    1;1  0     0       0     ~     f2SJ    ~
                                                                                                      ~
                 -10                                       ~

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                 -20
                 -30       *                          +                                           .b  *
                           **                                                             +       '"
                 -40      **                               x X
                                                                                    +     x A
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                 -50                                     ..+ ~.            .*   *      **       .*    .*

0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Normalized Thickness (x/t) Figure 13: Residual Stress Comparison at 70°F Before and After PWHT File No.: 1400669.322 Page 34 of38 Revision: 0 F0306-01RI

120 A t::. As*Welded 0 PWHT 100 Clad Interface S 80 t:: (1nlerDce)

                --'en A' (Inlelfllce)
                  .¥ t::.

60 ~ e'"'" en fti

                              ~
                                         ~~

4 0 A A

s * (/nIerface)

2 (

0:: '" Q) 40 "C CIS 0 0 0 .../:i. (lnIedace) 0 20 Data from EPRI TR*101989 o t::.

• Thicker Clad Tes1S, Interface at Depth

                                                            ~        ~

Shown 00 0 0 0

                          *20 A

t::. 95132r1 40 o 0.2 0.4 0.6 0.8 1.0 Distance from Clad Surface (inches) Figure 14: Measured Through-Wall Residual Stresses for PWHT Notes:

1. Figure is obtained from EPRI report TR-I05697 [10].

2. Measurements show little to no stress reduction in the cladding after PWHT.

3. Measurements show significant stress reduction in the base metal after PWHT.

File No.: 1400669.322 Page 35 of38 Revision: 0 F0306-01RI

JIl'DAL SJIDTICN S'I'F..P-l404 SUB =3

    '!'lME-2088

'W! (AVG)

RS'iS 0 Il-<< . 1353..16 s.N ~ . 056563

     ~     - 73 . 741 Figure 15: Predicted von Mises Residual Stress at 700 F after Hydrostatic Test File No.: 1400669.322                                                                               Page 36 of38 Revision: 0 F0306-01RI

1IO:lAl, OCJUn'JCN STF.r-1413 SOB -3

     'rIMEi-2106 SX           (AVG)

RSYS !> Il<< . 13462

     ~     - 10 . 5442 SMK -13 . 7349 Figure 16: Predicted Radial Residual Stress + Operating Conditions (5 th NOC Cycle)

Note: I. Radial stresses shown in the nozzle axis radial direction. File No.: 1400669.322 Page 37 of38 Revision: 0 F0306-01RI

mw., s:um:<N S'lW'-1413 SUB -3

    'rlMl:)o2106 SY           (AI,C)

RSYS 5 r;HX . 13462 9-N -10. 4201 SMK -44 . 7962 Figure 17: Predicted Hoop Residual Stress + Operating Conditions (5 th NOC Cycle) Note:

1. Hoop stresses shown in the nozzle axis circumferential direction.

File No.: 1400669.322 Page 38 of38 Revision: 0 F0306-01Rl

e BtnR:1InI ""."", Associatss, Inc.- APPENDIX A COMPUTER FILES LISTING File No.: 1400669.322 Page A-I of A-2 Revision: 0 F0306-01RI

File Name Description Palisades CL.INP Input file to create base geometry model [1] MProp_MISO.INP Elastic-plastic Material properties inputs [1] Autonugsel.mac Macro that groups elements into nuggets BCNUGGET3D.INP Weld pass and model boundary definition file THERMAL3D.INP Input file to perform the thermal pass of welding simulation THM PWHT.INP Input file to perform the thermal pass of PWHT STRESS3D.INP Input file to perform the stress pass of welding simulation CBC.INP Input file to apply mechanical boundary conditions THM_PWHT_mntr.inp Processed thermal pass load steps for PWHT WELD#_ mntr.inp Processed thermal pass load steps for stress pass # = 1-3

     *.mac             WRS analysis macro files required for analysis THERMAL3D.TXT     Parameter input file for thermal pass of welding simulation STRESS3D.TXT      Parameter input file for stress pass GenStress.mac     Macro to extract PWHT stress results GETPATH.TXT       Through-wall stress path definition to extract PWHT stress results File No.: 1400669.322                                                              Page A-2 of A-2 Revision: 0 F0306-01RI

S)Structurallnlegrlty Associates. Inc.* File No.: 1400669.323 Project No.: 1400669 CALCULATION PACKAGE Quality Program Type: ~ Nuclear D Commercial PROJECT NAME: Palisades Flaw Readiness Program for lR24 NDE Inspection CONTRACT NO.: 10426669 CLIENT: PLANT: Entergy Nuclear Operations, Inc. Palisades Nuclear Plant CALCULATION TITLE: Crack Growth Analysis of the Cold Leg Bounding Nozzle Project Manager Preparer(s) & Document Affected Revision Description Approval Checker(s) Revision Pages Signature & Date Signatures & Date o 1 - 23 Initial Issue Preparer: A-I - A-2 Computer Files ;t~--=7- I)J~~~ Norman Eng Wilson Wong NE 5/11115 WW 5/11115 Checkers:

                                                                                    ~~   Minji Fong MF 5/11/15 Gole Mukhim GSM 5/11/15 Page 1 of23 F0306*01R2

Table of Contents 1.0 OBJECTIVE .................................................................................................................. 4 2.0 DESIGN INPUTS .......................................................................................................... 4 2.1 Piping Interface Loads ....................................................................................... 4 2.2 Residual Stresses at Normal Operating Temperature and Pressure ................... 5 2.3 Mechanical Load Boundary Conditions ............................................................ 5 2.4 Crack Growth Rate ............................................................................................ 5 3.0 ASSUMPTIONS ............................................................................................................ 6 4.0 DETERMINATION OF STRESS INTENSITY FACTOR .......................................... 6 4.1 Crack Face Pressure Application ....................................................................... 6 4.2 K Calculation for Circumferential Flaws .......................................................... 7 4.2.1 Finite Element Model with Circumferential Flaws ........................................... 7 4.2.2 Stress Intensity Factor Results........................................................................... 8 4.3 K Calculation for Axial Flaws ........................................................................... 8 4.3.1 Finite Element Model with Axial Flaws ............................................................ 8 4.3.2 Stress Intensity Factor Results........................................................................... 8 5.0 CRACK GROWTH CALCULATION .......................................................................... 9

6.0 CONCLUSION

S ........................................................................................................... 9

7.0 REFERENCES

............................................................................................................ 11 APPENDIX A COMPUTER FILE LISTING ...................................................................... A-I File No.: 1400669.323                                                                                                                  Page 2 of23 Revision: 0 F0306-01R2

List of Tables Table 1: Stress Intensity Factors for Circumferential Flaws .................................................. 12 Table 2: Stress Intensity Factors for Axial Flaws ................................................................... 12 Table 3: Crack Growth Time to 75% Through-WalL ............................................................ 12 Table 4: Crack Growth Time to 95% Through-Wall .............................................................. 12 Table 5: Allowable Detected Flaw Size ................................................................................. 13 List of Figures Figure 1. Base Finite Element Model Mesh ............................................................................ 14 Figure 2. Applied Mechanical Load Boundary Conditions ..................................................... 15 Figure 3. Circumferential Flaw with Crack Tip Elements Inserted ......................................... 16 Figure 4. Transferred Residual Stress + NOC + Pressure Stress for Circumferential Flaws .. 17 Figure 5. Stress Intensity Factors as a Function of Depth for Circumferential Flaws ............. 18 Figure 6. Axial Flaws with Crack Tip Elements Inserted ....................................................... 19 Figure 7. Transferred Residual Stress + NOC + Pressure Stress for Axial Flaws .................. 20 Figure 8. Stress Intensity Factors as a Function of Depth for Axial Flaws ............................. 21 Figure 9. Crack Growth for All Flaw Types with 0.025" Initial Flaw Size ............................ 22 Figure 10. Crack Growth for All Flaw Types with 0.1" Initial Flaw Size .............................. 23 File No.: 1400669.323 Page 3 of23 Revision: 0 F0306-01R2

1.0 OBJECTIVE The objective of this calculation package is to detennine maximum allowable flaw sizes for 18 and 36 months of continued operation based on crack growth analyses for a series of postulated flaws in the cold leg bounding nozzle boss weld in support of a Primary Water Stress Corrosion Cracking (PWSCC) susceptibility study at the Palisades Nuclear Plant (Palisades). The stresses due to the cold leg pipe interface loads which are detennined in this calculation, and residual stresses extracted from a previous analysis [1], are used to calculate the stress intensity factors (K) which are used to perform crack growth analyses. The PWSCC crack growth analyses are performed using the pc-CRACK [2] program for both circumferential and axial flaws. The allowable detected flaw sizes are determined by back-calculating the predicted growth time to a maximum flaw size of75% through wall thickness per ASME Code Section XI, IWB-3643. 2.0 DESIGN INPUTS The finite element model shown in Figure 1 was developed in Reference [3] and is used for the determination of stress intensity factors. 2.1 Piping Interface Loads Reference 4 [PDF file page 88] indicates that, for the cold leg, the bounding thermal transient stress is 7.307 ksi due to case Thermal 009, the deadweight (DW) stress is 0.459 ksi and the friction stress is 0.429 ksi. The cold leg loads are applied as an equivalent bending moment to the axial free end ofthe modeled cold leg. The equivalent bending moment is based on the combined stress which is assumed to occur at the outside surface of the cold leg. The maximum combined bending stress is: DW + Friction + Thermal = 0.459 + 0.429 + 7.307 = 8.195 ksi The moment based on the bending stress is calculated as: M = (j.J = 7r. (17.84375 4 -14.84375 4 ).8.195 =19056 in-ki s OR 4 17.84375 P where, M = moment applied to the free end of the cold leg (J' = stress on the cold leg pipe I = Moment ofInertia - (1t/4)(OR4 -IR4) IR = Inside radius of nozzle (in) = 14.84375" [3] OR = Outside radius of nozzle (in) = 17.84375 [3] File No.: 1400669.323 Page 4 of23 Revision: 0 F0306-01R2

Since half the cold leg pipe is modeled, the equivalent moment applied to the model is 9528 in-kips (= 19056 in-kips /2). The moment is applied to the axial free end of the cold leg run piping by means of a pilot node pair to transfer the loading. The pilot node pair is composed of a target node at the center of the pipe (ANSYS TARGE170 element) and a set of surface contact elements on the axial end of the pipe (ANSYS CONTA174 element). The surface elements are bonded to the pilot node in a slave/master coupling relationship, so that the moment load applied to the pilot node is transferred to the end of the pipe. The cold leg bounding nozzle piping loads are considered to have negligible effects on the resulting K's for the boss weld, and are therefore not considered. 2.2 Residual Stresses at Normal Operating Temperature and Pressure Residual stresses at the fifth operating condition cycle (at time = 21 06 minutes) are taken from Reference [1]. These stresses include the effects of normal operating temperature of 537°F and pressure of 2085 psig [1]. 2.3 Mechanical Load Boundary Conditions The mechanical load boundary conditions for the stress analyses are symmetric boundary conditions at the symmetry planes of the model, axial displacement restraint at the end of the nozzle, and axial displacement restraint on the pilot node, as shown in Figure 2. In the case where axial flaws are modeled on the symmetry planes, the boundary conditions are released at the nodes where the flaw exists. 2.4 Crack Growth Rate The default PWSCC growth rate in pc-CRACK [2] is used. This relation is based on expressions in Reference [5, Section 4.3] and the resulting equation for the crack growth rate is as follows: da [Q( T+460 dt -_ C exp - 1 1 Tref +460 )](K - K)P til for K > Kth For times (t) in hours, temperatures (T and Tref) in OF, crack length (a) in inches and K in ksi--iin, the following reference values are used: Tref= 617°F C = 2.47xlO-7 (constant) p= 1.6 (constant) Q = 28181.8°R (constant) Kth = 0 (threshold stress intensity factor below which there is no crack growth) T = operating temperature at location of crack File No.: 1400669.323 Page 5 of23 Revision: 0 F0306-01R2

3.0 ASSUMPTIONS The following assumptions are used in this analyses:

• The cold leg bounding nozzle piping loads are not considered in calculating stress intensity factors since loads on the nozzle do not produce Mode I crack opening stress intensity factors that contribute to crack growth in the boss weld.
• The maximum combined stress on the cold leg piping is assumed to occur at the outside surface of the cold leg.

4.0 DETERMINATION OF STRESS INTENSITY FACTOR The stresses described in this section are used with a modified version of the finite element model (FEM) developed previously in Reference [3] to determine stress intensity factors. The modification of the FEM consists of adding crack tip elements as addressed in Section 4.2 and 4.3. The stress intensity factors (Ks) are calculated using the KCALC feature in ANSYS [6] which is based on the linear elastic fracture mechanics (LEFM) principles. For the LEFM evaluations, only the elastic properties are used in the FEA. 4.1 Crack Face Pressure Application In order to determine the Ks for the circumferential and axial flaws due to residual stresses, the stresses on the boss weld-to-nozzle interface, at the fifth operating condition (at time = 2106 minutes in the residual stress analysis [1 D, are extracted from the residual stress analysis and reapplied on the crack face as surface pressure loading. This approach is based on the load superposition principle [7], which is utilized to transfer the stresses from the weld residual stress finite element model onto the fracture mechanics finite element model that contains crack tip elements. The superposition technique is based on the principle that, in the linear elastic regime, stress intensity factors of the same mode, which are due to different loads, are additive (similar to stress components in the same direction). The superposition method can be summarized with the following sketches [7, page 66]: (a) File No.: 1400669.323 Page 6 of23 Revision: 0 F0306-01R2

A load p(x) on an uncracked body, Sketch (a), produces a nonnal stress distribution p(x) on Plane A-B. The superposition principle is illustrated by Sketches (b), (c), and (d) of the same body with a crack at Plane A-B. The stress intensity factors resulting from these loading cases are such that: KI(b) = KI(C) + KI(d) Thus, KI(d) = 0 because the crack is closed, and: KI(b) = KI(C) This means that the stress intensity factor obtained from subjecting the cracked body to a nominal load p(x) is equal to the stress intensity factor resulting from loading the crack faces with the same stress distribution p(x) at the same crack location in the uncracked body. 4.2 K Calculation for Circumferential Flaws 4.2.1 Finite Element Model with Circumferential Flaws The stress intensity factors for full circumferential flaws in the nozzle boss weld are determined by finite element analysis using detenninistic linear elastic fracture mechanics (LEFM) principles. As a result, five fracture mechanics finite element models are derived to include "collapsed" crack meshing that represent full (360°) circumferential flaws surrounding the nozzle at various depths within the boss weld. The circumferential flaws align with the interface between the boss weld and the nozzle. The modeled flaw depths are: 0.13", 0.88", 1.45",2.32", and 2.99" as measured at the 0° axial side of the cold leg plpe. The modeling of the flaws, or cracks, involves splitting the crack plane and then inserting "collapsed" mesh around the crack tips followed by concentrated mesh refinements that surround the "collapsed" mesh, and are referred to as "crack tip elements". This step is implemented on a source finite element model without the cracks (the FEM developed in Reference 3) where crack tip elements are inserted by an in-house developed ANSYS macro. For the fracture mechanics models, 20-node quadratic solid elements (ANSYS SOLID95) are used in the crack tip region, while 8-node solid elements (ANSYS SOLID185) are used everywhere else in the model. The mid-side nodes for the SOLID95 elements around the crack tips are shifted to the "quarter point" locations to properly capture the singularities at the crack tips, consistent with ANSYS recommendations. The finite element model for the 2.99" deep circumferential flaw, with the crack tip mesh, is shown in Figure 3 as an example; the crack tip mesh for the other crack depths follows the same pattern. File No.: 1400669.323 Page 70f23 Revision: 0 F0306-01R2

The quarter point mid-side nodes combined with the extra layers of concentrated elements around the crack tips provide sufficient mesh refmement to determine the stress intensity factors for the fracture mechanics analyses. 4.2.2 Stress Intensity Factor Results The radial stresses (radial to the nozzle axis) on the weld/nozzle interface are transferred to the circumferential flaws as crack face pressure per the superposition principle described in Section 4.1. Figure 4 depicts, as an example, the transferred radial stresses as crack face pressure for the 2.99" circumferential crack depth. During the crack face pressure transfer, the operating pressure of 2085 psi is added to the crack face pressure to account for the internal pressure acting on the crack face due to cracking. A far field in-plane bending moment per Section 2.1 is also applied to the free end of the cold leg run piping to account for the pipe moment in the main loop piping. Each crack model is analyzed as a steady state stress pass at the operating and reference temperature of 537°F [1] in order to use the material properties at the operating temperature, but without inducing additional thermal stresses. At the completion of each analysis, the ANSYS KCALC post-processing is performed to extract the K's at each crack tip node around the nozzle. The maximum K results are summarized in Table 1 for various crack depth ratios "aft". Since the crack tip location is same in the circumferential flaw, the maximum K from all locations at each crack size is conservatively used for the K vs. a profile. The "K vs. aft" trends are then plotted in Figure 5. 4.3 K Calculation for Axial Flaws 4.3.1 Finite Element Model with Axial Flaws The stress intensity factors for axial flaws are determined using the same methodology as the circumferential flaws. However, the mesh of weld nuggets was removed to insert thumbnail shape flaws in the model. Also, the orientation and shape of the flaws allow all crack depths at the 0° and 90° faces of the symmetric cold leg pipe model to be inserted simultaneously. Figure 6 shows the five modeled crack depths (0.25",0.78", 1.37", 2.16", and 2.90") on the 0° face (cold leg axial face) and 90° face with crack tip elements inserted. The modeling of the axial flaws uses the same crack tip elements as described in Section 4.2.1. The crack tip mesh is the same pattern used in the circumferential flaws and is shown in Figure 6 for the axial flaws at the 0° and 90° faces. 4.3.2 Stress Intensity Factor Results Similar to the circumferential flaw analyses, the crack opening residual stresses and additional operating pressure are transferred to the axial flaws as crack face pressure. Figure 7 depicts, as an example, the File No. : 1400669.323 Page 8 of23 Revision: 0 F0306-01R2

transferred hoop stresses as crack face pressure for the axial flaws. In addition, a far field in-plane bending moment per Section 2.1 is also applied to the free end of the cold leg run piping to account for the pipe moment in the main loop piping. The K results at the deepest point of the flaws are summarized in Table 2 for various crack depth ratios "aft" and plotted in Figure 8. Since the deepest point of the postulated axial flaws has the smallest remaining wall thickness, the K at the deepest point is used for the K vs a profile. 5.0 CRACK GROWTH CALCULATION Stress intensity factors (Ks) at four depths for 360 0 inside surface connected, part-through-wall circumferential flaws as well as two axial thwnbnail flaws at the O-and 90-degree azimuthal locations of the nozzle, are calculated using finite element analysis (FEA). For the circwnferential flaw, the maximwn K values around the nozzle circwnference for each flaw depth are extracted and used as input into pc-CRACK to perform the PWSCC crack growth analyses. For the axial flaws, the K at the deep point of the thwnbnail shape is used as input for performing the PWSCC crack growth analyses. Since the K vs. a profile is used as input, the shape of the component is not relevant. For the crack growth analyses, two initial flaw sizes were chosen. These are based on expected engineering flaw sizes that could be present for a crack that would then grow by PWSCC. The final flaw size for these analyses is 75% of the wall thickness. This final depth is chosen as it is the maximum allowable flaw depth per Section XI of the ASME Code for pipe flaw evaluations. Additionally, a final flaw size of 95% of the wall thickness is also considered in this calculation. The following are the additional parameters needed for the crack growth calculations: Two initial crack depths = 0.025" and 0.1" (asswned) Temperature = 537°F (operating temperature [1]) Wall thickness = 3" (Cold Leg thickness [3]) The resulting crack depths for the circumferential and axial flaws, as a function of time, as calculated by pc-CRACK are shown in Figure 9 for the 0.025" initial flaw size and Figure 10 for the 0.1" initial flaw size. The time for a flaw to grow from the initial flaw size to 75% and 95% though-wall is tabulated in Table 3 and Table 4 for both circwnferential and axial flaw types, respectively. Table 5 shows the allowable detected flaw sizes for the postulated flaws if continued operation for 18 and 36 months is considered.

6.0 CONCLUSION

S Stress intensity factors were calculated for the 360 0 circumferential flaws as well as the axial flaws at the 0 0 and 90 0 locations. The stress intensity factors were calculated using residual stress distributions for residual stress plus normal operating conditions. In addition, a far field in-plane bending moment is File No.: 1400669.323 Page 9 of23 Revision: 0 F0306-01R2

applied to the free end of the cold leg run piping to account for piping moments in the main loop piping. This combined loading is used for the determination of the stress intensity factors for both the circumferential and axial flaws. Figure 5 and Figure 8 as well as Table 1 and Table 2, show the calculated stress intensity factors for the circumferential and axial flaws. Crack growth evaluations were performed for circumferential and axial flaw configurations using two different initial flaw sizes. As shown in Figure 9 and Table 3, the shortest time for an initial 0.025" deep flaw to grow to 75% through-wall in all cases is 55.6 years for a circumferential flaw. Figure 10 and Table 3 show that the shortest time for an initial 0.1" deep flaw to grow to 75% through-wall in all cases is 53.5 years for a circumferential flaw. Table 5 shows the maximum allowable detected flaw sizes for 18 and 36 months of continued operation. File No.: 1400669.323 Page 10 of23 Revision: 0 F0306-01R2

l)BInIc",,., ,,,,.,,,,, Associates, Inc.-

7.0 REFERENCES

1. SI Calculation No. 1400669.322, Rev. 0, "Cold Leg Bounding Nozzle Weld Residual Stress Analysis. "

2. pc-CRACK 4.1, Version 4.1 CS, Structural Integrity Associates, December 2013.

3. SI Calculation No. 1400669.320, Rev. 0, "Finite Element Model Development for the Cold Leg Drain, Spray, and Charging Nozzles."

4. Palisades Document, Report No. CENC-1115, "Analytical Report for Consumers Power Piping,"

SI File No. 1300086.204.

5. Materials Reliability Program: Crack Growth Ratesfor Evaluating Primary Water Stress Corrosion cracking (PWSCC) ofAlloy 82, 182 and 132 Welds (MRP-115), EPRI, Palo Alto, CA:

2004, 1006696.

6. ANSYS Mechanical APDL and PrepPost, Release 14.5 (wi Service Pack 1), ANSYS, Inc.,

September 2012.

7. Anderson, T. L., "Fracture Mechanics Fundamentals and Applications," Second Edition, CRC Press, 1995.

File No.: 1400669.323 Page 11 of23 Revision: 0 F0306-01R2

Table 1: Stress Intensity Factors for Circumferential Flaws Depth MaxK alt (in) (ksi-in A O.5) 0.13 0.04 22.07 0.83 0.28 28.50 1.42 0.47 20.84 2.31 0.77 20.97 2.99 1.00 48.27 Table 2: Stress Intensity Factors for Axial Flaws CL Axial Plane 0° CL Circ. Plane 90° Crack Depth K at Deep Pt Crack Depth KatDeepPt alt alt (in) (ksi-in°.s) (in) (ksi-in°.S) 0.25 0.08 21.26 0.24 0.08 18.43 0.78 0.26 20.95 0.83 0.28 19.00 1.37 0.46 19.58 1.43 0.48 20.82 2.16 0.72 22.89 2.19 0.73 25.67 2.90 0.97 28.34 2.85 0.95 30.93 Table 3: Crack Growth Time to 75% Through-Wall Axial Crack Axial Crack Initial Flaw Size Circ. Crack (0° plane) (90° plane) (in) (years) (years) (years) 0.025 64.5 67.2 55.6 0.100 62.2 64.4 53.5 Table 4: Crack Growth Time to 95% Through-Wall Axial Crack Axial Crack Initial Flaw Size Circ. Crack (0° plane) (90° plane) (in) (years) (years) (years) 0.025 77.0 77.9 66.2 0.100 74.6 75.0 64.0 File No.: 1400669.323 Page 12 of23 Revision: 0 F0306-01R2

S)Btntcllnl ,,,,.,,,,, Associates. Inc.- Table 5: Allowable Detected Flaw Size Allowable Detected Flaw Size (aft) Cold Leg Thickness, t = 3.00" Months of Axial Flaw Axial Flaw Circumferential Continued at 0 plane 0 at 900 plane Flaw Operation aft a{inl aft a (in) aft a (in) 18 0.7238 2.1715 0.7202 2.1605 0.7269 2.1807 36 0.6871 2.0613 0.6788 2.0363 0.6273 1.8818 File No.: 1400669.323 Page 13 of23 Revision: 0 F0306-01R2

Figure 1. Base Finite Element Model Mesh File No.: 1400669.323 Page 14 of23 Revision: 0 F0306-01R2

l ruMNl'S MAT mM Axial displacement U restraint Pilot Node and Axial

                     \

Restraint

                       ~

Symmetry boundary conditions Fracture mechanics anal ysi s using 1mported crack face stress Figure 2. Applied Mechanical Load Boundary Conditions File No.: 1400669.323 Page 15 of23 Revision: 0 F0306-01R2

Figure 3. Circumferential Flaw with Crack Tip Elements Inserted (Note: Deepest circumferential flaw shown for example) File No.: 1400669.323 Page 16 of23 Revision: 0 F0306-01R2

Figure 4. Transferred Residual Stress + NOC + Pressure Stress for Circumferential Flaws (Note: Deepest circumferential flaw shown for example) File No.: 1400669.323 Page 17 of23 Revision: 0 F0306-01R2

60 I 50 iii' 40 d

        <C "i
        'iii
        ..:t:

X 30 IV

?! 20 10 0.00 0.20 0.40 0.60 0.80 1.00 Depth (aft)

Figure 5. Stress Intensity Factors as a Function of Depth for Circumferential Flaws File No.: 1400669.323 Page 18 of23 Revision: 0 F0306-01R2

0° plane 90° plane Figure 6. Axial Flaws with Crack Tip Elements Inserted File No.: 1400669.323 Page 19 of23 Revision: 0 F0306-01R2

0° plane 90° plane Figure 7. Transferred Residual Stress + NOC + Pressure Stress for Axial Flaws File No.: 1400669.323 Page 20 of23 Revision: 0 F0306-01R2

35 30 in ci 25

     ~ 20
     'iii
     ~
     ~    15
      )(

IV

     ~

10

                                                                                     ~ Axial_O 5
                                                                                     -   Axial_90 o

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00 Depth (aft) Figure 8. Stress Intensity Factors as a Function of Depth for Axial Flaws File No.: 1400669.323 Page 21 of23 Revision: 0 F0306-01R2

1.0 0.9 0.8 0.7

     -..g.
     .:t:.

IV 0.6

     .c 0.5 c
      ~

IV 0.4

     ~

0.3 0.2 - - Circumferential

                                                                             - - - Axial_O 0.1

_ . - AxiaL90 0.0 a 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Time (yrs) Figure 9. Crack Growth for All Flaw Types with 0.025" Initial Flaw Size File No.: 1400669.323 Page 22 of23 Revision: 0 F0306-01R2

1 0.9 0.8 0.7

     ~0.6
      ...~ 0.5
     ..c 0

IV 0.4 i!: 0.3 0.2 - - Circumferential

                                                                            - - - AxiaLO 0.1
                                                                            -   . - Axial_90 0

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 Time (yrs) Figure 10. Crack Growth for All Flaw Types with 0.1" Initial Flaw Size File No.: 1400669.323 Page 23 of23 Revision: 0 F0306-01R2

e Blntclrnl ,,,,.,,,,, Assoc/atss, Inc,- APPENDIX A COMPUTER FILE LISTING File No.: 1400669.323 Page A-I of A-2 Revision: 0 F0306-01R2

e BltBlrnlI",.,,,,, Associates, Inc.- File Descri~tion Palisades CL.DB Base model geometry for crack tip insertion [3] CL axial.INP Input file to modify base mesh for axial crack tip insertion BCNODES.INP Input file for nodal component definitions FM CL AXL *.INP Geometry input files to create circumferential flaw at specified depth. * = 05, 30, 50, 75, and 95 FM- CL- AXL *- COORD.INP Input files to determine circumferential crack face element centroid coordinates. * = 05, 30, 50, 75, and 95 FM- CL- AXL *- GETSTR.INP Input files to extract circumferential crack face stresses from residual stress analysis. * = 05, 30, 50, 75, and 95 FM- CL- AXL*- IMPORT.INP Input files to transfer stresses into circumferential crack face pressure (plus operating pressure on crack face and applied pipe moment). * = 05, 30, 50, 75, and 95 Axial* Nodes.INP Crack tip definition file for axial cracks FM- PALISADES- CL- C#.INP Geometry input files to create circumferential flaw at specified depth. # = 05, 30, 50, 75, and 95 FM- PALISADES- CL- C#- COORD.INP Input files to determine circumferential crack face element centroid coordinates. # = 05, 30, 50, 75, and 95 FM- PALISADES- CL- C#- GETSTR.INP Input files to extract circumferential crack face stresses from residual stress analysis. # = 05, 30, 50, 75, and 95 FM- PALISADES- CL- C#- IMPORT.INP Input files to transfer stresses into circumferential crack face pressure (plus operating pressure on crack face and applied pipe moment). # = 05, 30, 50, 75, and 95 NodesC#.INP Crack tip definition file for circumferential cracks Extracted circumferential crack face stresses from residual stress STR_FieldOper_STR_C##I.txt analysis. ## = 05, 30, 50, 75 , and 95 Extracted axial crack face stresses from residual stress analysis. STR_FieldOper_Axl**I.txt

                                        ** = 00, and 90 FM CL AXL ** IMPORT K.CSV             Formatted K result outputs for axial crack. ** = 00, and 90 FM- PALISADES- CL- C##- IMPORT- K. Formatted K result outputs for circumferential crack.

CSV ## = 05, 30, 50, 75, and 95 pc-CRACK PWSCC growth input file for circ flaw. CircFlaw_ $$$$.pcf

                                        $$$$ = 0025 and 01 , 0025 = 0.025" and 01 = OJ " initial flaw size pc-CRACK PWSCC growth input file for axial flaw on 0° plane.

AxialFlaw_0_$$$$.pcf

                                        $$$$ = 0025 and 01 pc-CRACK PWSCC growth input file for axial flaw on 90° plane.

AxialFlaw_90_$$$$.pcf

                                        $$$$ = 0025 and 01 pc-CRACK PWSCC growth output file for circ flaw.

CircFlaw_ $$$$.rpt

                                        $$$$ = 0025 and 01 pc-CRACK PWSCC growth output file for axial flaw on 0° plane.

AxialFlaw_0_$$$$.rpt

                                        $$$$ = 0025 and 01 pc-CRACK PWSCC growth output file for axial flaw on 90° plane.

AxialFlaw_90_$$$$.rpt

                                        $$$$ = 0025 and 0 I File No.: 1400669.323                                                                       Page A-2 of A-2 Revision: 0 F0306-01R2}}