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WCAP-18309-NP, Revision 0, Technical Justification for Eliminating Safety Injection Line Rupture as the Structural Design Basis for D.C. Cook, Units 1 and 2, Using Leak-Before-Break Methodology.
	ML18334A270
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Site:	Cook
Issue date:	01/31/2018
From:	Johnson E D; Westinghouse
To:	; Office of Nuclear Reactor Regulation
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ML18334A291	List: AEP-NRC-2018-66, Request for License Amendment to Technical Specification 3.4.15, RCS Leakage Detection Instrumentation, and Application of Leak-Before-Break Methodology; ML18334A268; ML18334A269; ML18334A270;
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{{#Wiki_filter:Enclosure 11 to AEP-NRC-2018-66 VVCAP-18309-NP, Revision O Technical Justification for Eliminating Safety Injection Line Rupture as the Structural Design Basis for D.C. Cook Units 1 and 2, Using Leak-Before-Break Methodology" (Non-Proprietary) WCAP-18309-NP Revision 0 WESTINGHOUSE NON-PROPRIETARY CLASS 3 Technical Ju.stification for Eliniinating*Safety Injection Line Rupture as the Structural Design January 2018 Basis *for D.C. Cook Units 1 and 2, Uslng Leak-Before-Break Methodology @~westinghouse

- - This record was final-approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 WCAP-18309.,NP Revision 0 Technical Justification for Eliminating Safety Injection Line Rupture as the Structural Design Basis for D.C. Cook Units 1 and 2,

Using Leak-Before-Break Methodology January 2018 Author: Eric D. Johnson* Structural Design and Analysis -II Reviewer:

Momo Wiratmo* Structural Design and Analysis -II Approved: Benjamin A. Leber, Manager* Structural Design and Analysis -II *Electronically approved records are authenticated in the electronic document management system. Westinghouse Electric Company LLC 1000 Westinghouse Drive Cranberry Township, PA 16066, USA © 2018 Westinghouse Electric Company LLC All Rights Reserved *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3, lll TABLE OF CONTENTS 1.0 Introduction ..................................... _ ................................................................................................... 1-1 1.1 Purpose ................................................................................................................................. 1-1 1.2 Scope and Objectives ............................................................................................................ 1-1 1.3 References ......................................................................

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1-2 2.0 Operation and Stability of the Reactor Coolant System ............. , ...................................................... 2-1 2.1 Stress Corrosion Cracking .................................................................................................... 2-1 2.2 Water Hammer ...................................................................................................................... 2-2 2.3 Low Cycle and High Cycle Fatigue ...................................................................................... 2-2 2.4 Other Possible Degradation During Service of the SI lines .................................................. 2-3 2.5 References ............................................................................................................................. 2-3 3.0 Pipe Geometry and Loading .............................................................................................................. 3-1 3.1 Calculations of Loads and Stresses ....................................................................................... 3-l 3.2 Loads for Leak Rate Evaluation ........................................................................................... 3-1 3.3 Load Combination for Crack Stability Analyses .................................................................. 3-2 3.4 References ............................................................................................................................. 3-3 4.0 Material Characterization .............................................................................................

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4-1 4.1 SI line Pipe Material and Weld Process ............................................................................... .4-l 4.2 Tensile Properties .................................................................................................................. 4-1 4.3 Reference .............................................................................................................................. 4-1 I 5'.0 Critical Locations ............................................................................................................................... 5-1 5.1 Critical Locations ....................................... , .......................................................................... 5-l 6.0 Leak Rate Predictions ...................................................................................................

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6-1 6.1 Introduction ..................................................

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6-1 6.2 _ General Considerations ....................................... , .. _. .............

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6-1 6.3-Calculation Method .......................................................................................................... -..... 6-1 6.4 Leak Rate Calculations ..............................................................................................

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6-2 6.5 References ............................................................................................................................. 6-3 7 .0 Fracture Mechanics Evaluation .......................................................................................................... 7-1 7.1 Global Failure Mechanism .................................................................................................... 7-1 7.2 Local Failure Mechanism .................................... ................................................................ 7-2 7.3 Results of Crack Stability Evaluation ................................................................................... 7-2 7.4 References ..............................................................................

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7-2 8.0 Assessment of Fatigue Crack Growth ................................................................................................ 8-1 8.1 References ..................................................................................................

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8-1 9.0 Assessment of Margins ....................................................................................................................... 9-1 10.0 Conclusions ...................................................................................................... -................................. 10-1 Appendix A: Limit Moment. ................................. .-....................................................................................... A-1 WCAP 0 l8309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47AM.

( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 iv LIST OF TABLES Table 3-1 Summary ofD.C. Cook Units 1 Piping Geometry and Normal Operating Condition for the Hot Leg and Cold Leg Safety Injection Lines ........................................................... 3-4 Table 3-2 Summary ofD.C. Cook Units 2 Piping Geometry and Normal Operating Condition for the Hot Leg and Cold Leg Safety Injection Lines .......................................................... .3-5 Table 3-3 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 1 Cold Leg ............................................................................................................................... 3-6 Table 3-4 Summary of D.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 2 Cold Leg ............................................................................................................................... 3-6 Table 3-5 Summary of D.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 3 Cold-:beg ..... : .....................................

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'. ................................. 3-7 Table 3-6 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 4 Cold Leg ............................................................................................................................... 3-7 Table 3-7 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 1 HotLeg ................................................................................................................................. 3-8

Table 3-8 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 2 HotLeg .................................................................................................................................

3-9 Table 3-9 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 3 Hot Leg ................................................................................................................... , ........... 3-10 Table 3-10 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 4 Hot Leg ............................................................................................................................... 3-1 l Table 3-11 Summary of D.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 1 Cold Leg ........................................................................... , ................................................. 3-12 Table 3-12 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 2 Cold Leg ............................................................................................................................. 3-12 Table 3-13 Summary of b.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 3 Cold Leg ............................................................................................................................. 3-13 Table 3-14 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 4 Cold Leg ....................................................................

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3-13 Table 3-15 Summary of D.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 1 Hot Leg ......................................................................................

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3-14 Table 3-16 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 2 HotLeg *************************************************************************************.:*****************************************3-15 Table 3-17 Summary of D.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 3 HotLeg ............................................................................................................................... 3-16

WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIBTARY CLASS 3 V Table 3-18 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 4 HotLeg ............................................................................................................................... 3-17 Table 3-19 Summary of D.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 1 Cold Leg ............................................................................................................................. 3-18 Table 3-20 Summary of D.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 2 Cold Leg ............................................................................................................................. 3-18 Table 3-21 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 3 Cold Leg ............................................................................................................................. 3-19 Table 3-22 Summary of D.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 4 Cold Leg ............................................................................................................................. 19 Table 3-23 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 1 Hot Leg ............................................................................................................................... 3-20 Table 3-24 Summary of D.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 2 HotLeg ............................................................................................................................... 3-21 Table 3-25 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 3 Hot Leg ............................................................................................................................... 3-22 Table 3-26 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 4 Hot Leg ............................................................................................................................... 3-23 Table 3-27 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 1 Cold L.eg ............................................................................................................................. 3-24 Table 3-28 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 2 Cold Leg ............................................................................................................................. 3-24 Table 3-29 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 3 Cold Leg ............................................................................................................................. 3-25 Table 3-30 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 4 Cold Leg ............................................................................................................................. 3-25 Table 3-31 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 1 Hot Leg ................................................ ,. ..................

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3-26 Table 3-32 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 2 Hot Leg ..... : ......................................................................................................................... 3-27 Table 3-33 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 3

Hot Leg ...................................................................................................................

-............ 3-28 Table 3-34 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 4 Hot Leg ............................................................................................................................... 3-29 Table 4-1 Material Properties for Operating Temperature Conditions on D.C. Cook Units 1 and 2 SI Lines ....................................................................................................................... 4-2 WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the P~IME system upon its validation) WESTINGHOUSE NON-PROPRJETARY CLASS 3 vi Table 5-1 Critical Analysis Location for Leak-Before-Break ofD.C. Cook Units 1 and 2 SI Lines ................................................................................................................................. 5-2 Table 6-1 Flaw Sizes Yielding a Leak Rate of 8 gpm for the D.C. Cook Units 1 and 2 SI lines .......... 6-4 Table 7-1 Flaw Stability Results for the D.C. Cook Units 1 and 2 SI Lil).es Based on Limit Load and EPFM .................................................................................................................... 7-3 Table 9-1 Leakage Flaw Sizes, Critical Flaw Sizes, and Margin for the D.C. Cook Units 1 and 2 SI Lines ....................................................................................................................... 9-2 WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) Figure 3-1 Figure 3-2 Figure 3-3 Figure 3-4 Figure 3-5 Figure 3-6 Figure 3-7 Figure 5-1 Figure 5-2 Figure 5-3 Figure 5-4 Figure 6-1 Figure 6-2 Figure 6-3 Figure 7-1 FigureA-1

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Vll LIST OF FIGURES D.C. Cook Units 1 and 2 Typical Piping Layout for SI lines ..............................................

3-30 D.C. Cook Unit 1 Cold Leg SI Line 1:-,ayout Showing Weld Locations with Node Points -Loops 1 through 4 ................................................................................................. 3-31 D.C. Cook Unit 1 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 1 and 4 ........................................................................................................ 3-32 D.C. Cook Unit 1 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 2 and 3 ........................................................................................................ 3-33 D.C. Cook Unit 2 Cold Leg SI Line Layout Showing Weld Locations with Node Points-Loops 1 through_4 ................................................................................................. 3-34 D.C. Cook Unit 2 Hot Leg SI Line Layout Sho"'.ing Weld Locations with Node Points-Loops 1 and 4 ........................................................................................................ 3-35 D.C. Cook Unit 2 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 2 and 3 ........................................................................................................ 3-3 6 D.C. Cook Unit 2 Cold Leg SI Line Critical Weld Locations .............................................. 5-3 D.C. Cook Unit 1 Hot Leg SI Line Loops 1 and 4 Critical Weld Locations ... .,_, .................... 5-4 D.C. Cook Unit 2 Hot Leg SI Line Loop 1 Critical Weld Locations .................................... 5-4 D.C. Cook Unit 2 Hot Leg SI Line Loop 3 Critical Weld Locations .................................... 5-5 Analytical Predictions of Critical Flow Rates of Steam-Water Mixtures ............................. 6-5 ]a,c,e Pressure Ratio as a Function of LID ............................................ 6-6 Idealized Pressure Drop Profile Through a Postulated Crack ............................................... 6-7 ]",c,e Stress Distribution .................................................................................. 7-4 Pipe with a Through-Wall Crack in Bending ................................................. , ..................... A-2 WCAP-18309-NP January 2018 Revision 0 -*This record was final a(:lproved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 1-1

1.0 INTRODUCTION

1.1 PURPOSE

The current structural design basis for the D.C. Cook Units 1 and 2 Safety Injection (SI) lines, including the 6-inch and 8-inch lines directly attached to the hot leg piping of the reactor coolant system (RCS) as well as the 10-inch and 6-inch lines attached to the accumulator line piping for injection into the cold leg of the RCS, require postulating non-mechanistic circumferential and longitudinal pipe breaks. This results in additional plant hardware (e.g., pipe whip restraints and jet shields) which would mitigate the . dynamic consequences of the pipe breaks. It is, therefore, highly desirable to be realistic in the postulation of pipe breaks for the SI lines. Presented in this report are the descriptions of a mechanistic pipe break evaluation method and the analytical results that can be used for establishing that a . .,,,, ... , .. ~-~rcum~erential type of break will . not occur within the SI lines. The evaluations consider that

circumferentially oriented flaws cover longitudinal cases. 1.2 SCOPE AND OBJECTIVES The purpose of this investigation is to demonstrate Leak-Before-Break (LBB) for the D.C. Cook Units 1 and 2 SI lines from the hot leg piping of each loop of the RCS through a check valve and up to an isolation valve, as well as the SI lines from the 10-inch Accumulator lines up to the first check valve. Schematic drawing of the piping systems are shown in Section 3 .0, Figure 3-1. The recommendations and criteria proposed in SRP 3.6.3 (References 1-1 and 1-2) are used in this evaluation.

The criteria and the resulting steps of the evaluation procedure can be briefly summarized as follows: 1. Calculate the applied loads based on as-built configuration. Identify the location(s) at which the highest faulted stress occurs. 2. Identify the materials and the material properties.

3. Postulate a through-wall flaw at the governing location(s).

The size of the flaw should be large enough so that the leakage is assured of detection with margin using the installed leak detection equipment when the pipe is subjected to normal operating loads. Demonstrate that there is a margin of 10 between the calculated leak rate and the leak detection capability.

4. Using maximum faulted loads in the stability analysis, demonstrate that there is a margin of 2 between the leakage size flaw and the critical size flaw. 5. Review the operating history to ascertain that operating experience has indicated no particular susceptibility to failure from the effects of corrosion, water hammer, or low and high cycle fatigue. 6. For the material types used in the plant, provide representative material properties.

7. Demonstrate margin on applied load by combining the faulted loads by absolute summation method. Introduction WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

\ WESTINGHOUSE NON-PROPRIETARY CLASS 3 1-2 This report provides a fracture mechanics demonstration of SI line piping integrity for D.C. Cook Units 1 and 2 consistent with the NRC's position for exemption from consideration of dynamic effects (Reference 1-3). It should be noted that the terms "flaw" and "crack" have the same meaning and are used interchangeably. "Governing location" and "critical location" are also used interchangeably throughout the report.

1.3 REFERENCES

1-1 Standard Review Plan: Public Comments Solicited; 3.6.3 Leak-Before-Break Evaluation Procedures; Federal Register/Vol. 52, No. 167/Friday August 28, 1987/Notices, pp. 32626-32633. 1-2 NUREG-0800 Revision 1, March 2007, Standard Review Plan: 3.6.3 Leak-Before-Break Evaluation Procedures. 1-3 Nuclear Regulato:ry Commission, 10 CFR 50, Modification of General Design Criteria 4 Requirements for Protection Against Dynamic Effects of Postulated Pipe Ruptures, Final Rule, Federal Register/Vol. 52, No. 207/Tuesday, October 27, 1987/Rules and Regulations, pp. 41288-41295. Introduction WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

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WESTINGHOUSE NON-PROPRIETARY CLASS 3 2-1 2.0 OPERATION AND STABILITY OF THE REACTOR COOLANT SYSTEM 2.1 STRESS CORROSION CRACKING The Westinghouse reactor coolant system (RCS) primary loops and connected Class 1 piping have* an operating history that demonstrates the inherent operating stability characteristics of the design. This includes a low susceptibility to cracking failure from the effects of corrosion ( e.g., intergranular stress corrosion cracking (IGSCC)). This operating history totals over 1400 reactor-years, including 16 plants each having over 30 years of operation, 10 other plants each with over 25 years of operation, 11 plants each with over 20 years of operation, and 12 plants each with over 15 years of operation. In.1978, the United States Nuclear Regulatory Commission (USNRC) formed the second Pipe Crack Study Group. (The first Pipe Crack Study Group (PCSG), established in 1975, addressed cracking in boiling water reactors only.) One of the objectives of the second PCSG was to include a review of the potential for stress corrosion cracking in Pressuri_zed Water Reactors (PWRs ). The results of the study performed by the PCSG were presented in NUREG-0531 (Reference 2-1) entitled "Investigation and Evaluation of Stress Corrosion Cracking in Piping of Light Water Reactor Plants." In that report the PCSG stated: "The PCSG has determined that the potential for stress-corrosion cracking in PWR primary system piping is extremely low because the ingredients that produce IGSCC are not all present. The use of hydrazine additives and a hydrogen overpressure limit the oxygen in the coolant to very low levels. Other impurities that might cause stress-corrosion cracking, such as halides or caustic, are also rigidly controlled. Only for brief periods during reactor shutdown when the coolant is exposed to the air and during the subsequent startup are conditions even marginally capable-of producing stress-corrosion cracking in the primary systems of PWRs. Operating experience in PWRs supports this determination. To date, no stress corrosion cracking has been reported in the primary piping or safe ends of any PWR." For stress corrosion cracking (SCC) to occur in piping, the following three conditions must exist simultaneously: high tensile stresses, susceptible material, and a corrosive environment. Since some residual stresses and some degree of material susceptibility exist in any stainless steel piping, the potential for stress corrosion is minimized by properly selecting a material immune to SCC as well as preventing the occurrence of a corrosive environment. The material specifications consider compatibility with the system's* operating envµ-onment (both internal and external) as well as other material in the system, applicable ASME Code rules, :fracture toughness, welding, fabrication, and processing. The elements of a water environment known to increase the susceptibility of austenitic stainless steel to stress corrosion are: oxygen, fluorides, chlorides, hydroxides, hydrogen peroxide, and reduced forms of sulfur (e.g., sulfides, sulfites, and thionates). Strict pipe cleaning standards prior to operation and careful control of water chemistry during plant operation are used to prevent the occurrence of a corrosive environment. Prior to being put into service, the piping is cleaned internally and externally. During flushes and preoperational testing, water ~hemistry is controlled in accordance with written specifications. Operation and Stability of the Reactor Coolant System WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 2-2 Requirements on chlorides, fluorides, conductivity, and pH are included in the acceptance criteria for the piping. During plant operation, the reactor coolant water chemistry is monitored and maintained within very specific limits. Contaminant concentrations are kept below the thresholds known to be conducive to stress corrosion cracking with the major water chemistry control standards being included in the plant operating procedures as a condition for plant operation. For example, during normal power operation, oxygen concentration in the RCS is expected to be in the parts per billion (ppb) range by controlling charging flow chemistry and maintaining hydrogen in the reactor coolant at specified concentrations. Halogen concentrations are also stringently controlled by maintaining concentrations of chlorides and fluorides within the specified limits. Thus during plant operation, the likelihood of stress corrosion cracking is minimized. During 1979, several instances of cracking in PWR feed water piping led to the establishment of the third PC-SG The investigations of the PCSG reported in NUREG-0691 (Reference 2-2) further confirmed that no occurrences ofIGSCC have been reported for PWR primary coolant systems .. Primary Water Stress Corrosion Cracking (PWSCC) occurred in the V. C. Summer reactor vessel hot leg nozzle, Alloy 82/182 weld. It should be noted that this susceptible material is not found at the D.C. Cook Units 1 and 2 SI lines. 2.2 WATER HAMMER Overall, there is a low potential for water hammer in the RCS and connecting SI lines since they are designed and operated to preclude the voiding condition in normally filled lines. The RCS and connecting SI lines including piping and components are designed for normal, upset, emergency, and faulted condition transients. The design requirements are conservative relative to both the number of transients and their severity. Relief valve actuation and the associated hydraulic transients following valve opening are considered in the system design. Other valve and pump actuations are relatively slow transients with no significant effect on the system dynamic loads. To ensure dynamic system stability, reactor coolant parameters are stringently controlled. Temperature during normal operation is maintained within a narrow range by the control rod positions; pressure is also controlled within a narrow range for steady-state conditions by the pressurizer heaters and pressurizer spray. The flow characteristics of the system remain constant during a fuel cycle because the only governing parameters, namely system resistance and the reactor coolant pump characteristics are controlled in the design process. Additionally, Westinghouse has instrumented typical reactor coolant systems to verify the flow and vibration characteristics of the system and the connecting auxiliary lines. Preoperational testing and operating experience has verified the Westinghouse approach. The operating transients of the RCS primary piping and connected SI lines are such that no significant water hammer can occur. 2.3 LOW CYCLE AND HIGH CYCLE FATIGUE The 1967 edition of the B3 l.l Code does not contain an explicit piping low cycle fatigue analysis requirement. The B3 l. l piping complies with a stress range reduction factor to be applied to the allowable stress as a way to address fatigue from full temperature cycles for thermal expansion stress evaluation. The stress range reduction factor is 1.0 (i.e., no reduction) for equivalent full temperature Operation and Stability of the Reactor Coolant System WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM._( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 2-3 cycles less than 7000. For D.C. Cook Units 1 and 2, the equivalent full temperature cycles for the applicable design transients are less than 7000, so no reduction is required. Pump vibrations during operation would result in high cycle fatigue loads in the piping system. During operation, an alarm signals the exceedance of the RC pump shaft vibration limits. Field vibration . measurements have been made on the reactor coolant loop piping in a number of plants during hot functional testing. Stresses in the elbow below the RCP have been found analytically to be very small, between 2 and 3 ksi at the highest. Field measurements on a typical PWR plant indicate vibration stress amplitudes less than 1 ksi. When translated to the connecting SI lines, these stresses would be even lower, well below the fatigue endurance limit for the SI line materials and would result in an applied stress intensity factor below the threshold for fatigue crack growth. 2.4 OTHER POSSIBLE DEGRADATION DURING SERVICE OF THE SI LINES The SI lines and the associated fittings for the D.C. Cook Nuclear Power Plants are forged product forms, which are not susceptible to toughness degradation due to thermal aging. The maximum normal operating temperature of the SI piping is about 618°F. This is well below the temperature that would cause any creep damage in stainless steel piping. Cleavage type failures are not a concern for the operating temperatures and the material used in the stainless steel piping of the SI lines. Wall thinning by erosion and erosion-corrosion effects should not occur in the SI piping due to the low velocity, typically less than 1.0 ft/sec and the stainless steel material, which is highly resistant to these degradation mechanisms. Per NUREG-0691 (Reference 2-2), a study on pipe cracking in PWR piping reported only two incidents of wall thinning in stainless steel pipe and these were not in the SI lines. The cause of wall thinning is related to high water velocity and is therefore clearly not a mechanism that would affect the SI piping. Brittle fracture for stainless steel material occurs when the operating temperature is about -200°F. SI line operating temperature is higher than 120°F and therefore, brittle fracture is not a concern for the SI lines.

2.5 REFERENCES

2-1 Investigation and Evaluation of Stress-Corrosion Cracking in Piping of Light Water Reactor Plants, NUREG-0531, U.S. Nuclear Regulatory Commission, February 1979. 2-2 Investigation and Evaluation of Cracking Incidents in Piping in Pressurized Water Reactors, NUREG-0691, U.S. Nuclear Regulatory Commission, September 1980. Operation and Stability of the Reactor Coolant System WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 3.0 PIPE GEOMETRY AND LOADING 3.1 *CALCULATIONS OF LOADS AND STRESSES The stresses due to axial loads and bending moments are calculated by the following equation: where, F M cr =-+ cr F stress, psi axial load, lbs M moment, in-lbs A Z A pipe cross-sectional area, in 2 Z section modulus, in 3 The moments for the desired loading combinations are calculated by the following equation: where, Mx X component of moment, Torsion My Y component of bending moment Mz Z component of bending moment 3-1 (3-1) (3-2) The axial load and moments for leak rate predictions and crack stability analyses are computed by the methods to be explained in Sections 3.2 and 3.3. 3.2 LOADS FOR LEAK RATE EVALUATION The normal operating loads for leak rate predictions are calculated by the following equations: F FDw +Fm+ Fp (3-3) Mx CMx)Dw + CMx)m (3-4) My (MY)Dw + (My)m (3-5) Mz CMz)Dw + (Mz)m (3-6) Pipe Geometry and Loading January 2018 WCAP-18309-NP Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 The subscripts of the above equations represent the following loading cases: DW = TH p deadweight normal thermal expansion load due to internal pressure 3-2 This method of combining loads is often referred to as the algebraic sum method (References 3-1 and 3-2). The LBB evaluations do not include moment effects due to pressure loading since the moment loading is significantly dominated by the thermal loads for normal operation and by the seismic loads for faulted events. The dimensions and normal operating conditions are given in Tables 3-1 and 3-2. The loads based on this method of combination are provided in Tables 3-3 through 3-18 at all the weld locations. 3.3 LOAD COMBINATION FOR CRACK STABILITY ANALYSES In accordance with Standard Review Plan 3.6.3 (References 3-1 and 3-2), the absolute sum of loading components can be applied which results in higher magnitude of combined loads. If crack stability is demonstrated using these loads, the LBB margin on loads can be reduced from ,/2 to 1.0. The absolute summation ofloads is shown in the following equations: F = I Pow I+ IFTH I+ I Fp I+ I FssEINERTIA I+ I FssEAM I Mx = I (Mx)ow I + I (Mx)TH I + I CMx)ssEINERTIAI + I (Mx)ssEAMI My= I (My)ow I+ I (My)TH I+ I (My)ssEINERTIAI + I (My)ssEAMI Mz = I CMz)ow I + I CMz)~ I + I CMz)ssEINERTIAJ + I CMz)ssEAMI (3-7) (3-8) (3-9) (3-10) where subscript SSEINERTIA refers to safe shutdown earthquake inertia, SSEAM is safe shutdown earthquake anchor motion. It is* noted that the D.C. Cook piping analyses consider Design Basis Earthquake (DBE) as the seismic criteria, which is equivalent to Safe Shutdown Earthquake (SSE). The loads so determined are used in the fracture mechanics evaluations (Section 7 .0) to demonstrate the LBB margins at the locations established to be the governing locations. These loads at all the weld locations are given in Tables 3-19 and 3-34. Notes: For the cold leg SI lines, LBB analysis will not be performed at the locations beyond the first check valve. The cold leg SI line check valve, in conjunction with the IO-inch check valve on the Accumulator line, provides protection against break propagation. Any break beyond the second check valve will not have any effect on the primary loop piping system. Similar justification is considered for the hot leg .SI lines, in that LBB analysis will not be performed at the locations beyond the isolation valve. The check valve and isolation valve, in series on the hot leg SI..1j11es, provides protection against break propagation. Any break beyond the isolation valve will not have any effect on the primary loop piping Pipe Geometry and Loading

WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 3-3 system. Figure 3-1 illustrates the typical layout of the cold leg and hot leg SI lines, showing segments, for D.C. Cook Units 1 and. 2.

3.4 REFERENCES

3-1 Standard Review Plan: Public Comments Solicited; 3.6.3 Leak-Before-Break Evaluation Procedures; Federal RegisterNol. 52, No. 167/Friday, August 28, 1987/N"otices, pp. 32626-32633. 3-2 NUREG-0800 Revision 1, March 2007, Standard Review Plan: 3.6.3 Leak-Before-Break Evaluation Procedures. Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) I WESTINGHOUSE NON-PROPRIETARY CLASS 3 3-4 Table 3-1 Summary ofD.C. Cook Unit 1 Piping Geometry and Normal Operating Loop . 1 ---* *.* 2 3 4 Condition for the Hot Leg and Cold Leg Safety Injection Lines Outer Minimum Normal Operating Weld Location Wall Segment Diameter Thickness* Temperature Nodes (in) (in) (OF) 403F to 402 10.750 0.896 SI-CL-I 120 398 6.625 0.650 SI-HIA 181 to 174 6.625 0.650 618 . .-... SI-HL-II 170F to 152B 6.625 0.650 120 SI-HL-III 148Xto 132 8.625 0.731 120 400Nto 400F 10.750 0.896 SI-CL-I 120 406 6.625 0.650 SI-HL-I 511 to 500F 6.625 0.650 618 SI-HL-II 500F to 479 6.625 0.650 120 SI-HL-III 96X to 78 8.625 0.731 120 158F to 158N 10.750 0.896 SI-CL-I 120 152 6.625 0.650 SI-HL-I 550 to 536F 6.625 0.650 618 SI-HL-II 536F to 516 6.625 0.650 120 SI-HL-III 96Yto 78 8.625 0.731 120 294X 10.750 0.896 SI-CL-I 120 290 to 284 6.625 0.650 SI-HL-I 221 to 214 6.625 . 0.650 618 SI-HL-II 210F to 190 6.625 0.650 120 SI-HL-III 148Y to 132 8.625 0.731 120 Notes: Figure 3-1 shows the piping layout and segments. Figures 3-2 through 3-7 show the weld locations for each line analyzed. Material type is A376 TP316 or A403 WP316. Pressure (psig) 2,235 2,235 -* .. ~*-** 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 Piping in segment SI-CL-I is IO-inch Schedule 140 and 6-inch Schedule 160. Piping in segment SI-HL-I and SI-HL-II is 6-inch Schedule 160. Piping in segment SI-HL-III is 8-inch Schedule 140. The minimum wall thickness is conservatively based at the weld counterbore and not per ASME Code requirement. Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 3-5 Table 3-2 Summary ofD.C. Cook Unit 2 Piping Geometry and Normal Operating Loop 1 ,-2 3 4 Condition for the Hot Leg and Cold Leg Safety Injection Lines Outer Minimum Normal Operating Weld Location Wall Segment Diameter Thickness Temperature Nodes (in) (in) C°F) 402F to 402N 10.750 0.896 SI-CL-I 120 400 to 388 6.625 0.650 SI-HL-I 181 to 174 6.625 0.650 618 ... ,. SI-HL-11 170F to 150 6.625 0.650 120 SI-HL-111 148X to 132 8.625 0.731 120 400Nto 400F 10.750 0.896 SI-CL-I 120 404 to 412 6.625 0.650 SI-HL-I 511 to 500F 6.625 0.650 618 SI-HL-11 500F to 479 6.625 0.650 120 SI-HL-111 96X to 78 8.625 0.731 120 158F to 158N 10.750 0.896 SI-CL-I 120 156 to 146 6.625 0.650 SI-HL-I 550 to 536F 6:625 0.650 618 SI-HL-11 536F to 516 6.625 0.650 120 SI-HL-111 96Yto 78 8.625 0.731 120 294X . 10.750 0.896 SI-CL-I 120 288F to 284 6.625 0.650 SI-HL-I 221 to 214 6.625 0.650 618 SI-HL-11 210F to 188 6.625 0.650 120 -SI-HL-III 148Yto 132 8.625 0.731 120 Notes: Figure 3-1 shows the piping layout and segments. Figures 3-2 through 3-7 show the. weld locations for each line analyzed. Material type is A376 TP316 or A403 WP316. Pressure (psig) 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 2,235 Piping in segment SI-CL-I is 10-inch Schedule 140 and 6-inch Schedule 160. Piping in segment SI-HL-I and SI-HL-11 is 6-inch Schedule 160. Piping in segment SI-HL-III is 8-inch Schedule 140. The minimum wall thickness is conservatively based at the weld counterbore and not per AS:ME Code requirement. Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-3 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 1 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbt) (in-lbf) (psi) -.. 403F 141,396 52,841 5,937 402 141,558 41,557 5,764 398 49,122 39,885 6,427

Notes: See Figure 3-2 for piping layout. Axial force includes pressure.

Table 3-4 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 2 Cold Leg Weld Location Axial Force Node (lbf) 400N 140,202 400F 140,013 406 48,909 Notes: See Figure 3-2 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 54,708 5,924 42,332 5,721 40,039 6,419 3-6 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRlETARY CLASS 3 Table 3-5 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 3 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbf) (in-lbf) (psi) 158F 141,219 58,379 6,019 158N 141,329 46,611 5,836 ... 152 50,225 43,494

6,735 Notes: See Figure 3-2 for piping layout. Axial force includes pressure.

Table 3-6 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 4 Cold Leg Weld Location Axial Force Node (lbf) 294X 141,911 290 50,808 288N 49,051 286F 50,410 284 50,922 Notes: See Figure 3-2 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 59,081 6,055 55,526 7,506 46,049 6,792 29,948 5,935 12,978 4,956 3-7 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table3-7 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 1 Hot Leg Weld Location Axial Force Node (lbf) 181 50,846 178 49,473 174 50,106 170F 51,158 170N 49,871 168F 50,007 168N 51,138 164F 51,138 164N 50,487 162F 51,093 162N 48,405 156F 49,749 155 49,319 154N 50,310 152 50,310 148X 90,587 148T. 90,133 146F 90,116 146N 89,976 i44F 89,976 144N 89,867 142F 89,867 142N 89,613 136 91,242 132 89,109 Notes: See Figure 3-3 for piping layout. Axial force includes pressure. (' Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 94,977 9,882 83,849 9,100 51,130 7,184 44,914 6,897 36,695 6,297 52,202 7,241 64,111 8,050 100,358 10,230 94,363 9,816 106,682 10,607 106,295 10,363 6,579 4,475 6,918 4,460 7,588 4,582 16,016 5,089 17,215 5,518 11,489 5,320 12,102 5,337 14,162 5,392 16,083 5,450 16,886 5,468 15,280 5,420 16,092 5,430 18,199 5,584 30,612 5,842 3-8 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-8 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 2 Hot Leg Weld Location Axial Force Node (lbf) 511 50,779 509 49,495 504 50,083 SOOF 51,380 SOON 49,855 498F 50,031 498N 51,386 494F 51,386 494N 50,543 492F 51,113 492N 48,679 490F 48,645 490N 48,168 484F 49,722 484N 50,290 482F 50,290 480F 49,429 480N 49,282 479 50,295 96X 90,572 96T 89,974 94F 89,964 94N 90,187 -H07-299 90,187 88F 89,948 88N-89,777 86F 89,777 86N 90,335 84F 89,908 78 90,000 Notes: See Figure 3-4 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 98,601 10,095 86,161 9,241 51,618 7,212 52,265 7,357 42,744 6,659 63,717 7,935 78,002 8,906 120,520 11,463 112,699 10,923 107,055 10,631 117,568 11,063 127,090 11,633 126,369 11,551 8,962 4,616 6,341 4,505 6,073 4,489 10,833 4,705 17,127 5,071 21,906 5,442 22,310 5,672 19,859 5,564 20,053 5,570 19,593 5,568 17,307 5,499 13,021 5,356 12,367 5,327 11,782 5,309 10,566 5,303 16,337 5,454 18,279 5,518 3-9 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-9 Summary ofD.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 3 Hot Leg Weld Location Axial Force Node (lbf) 550 50,974 546 50,363 540 50,362 536F 51,348 536N 49,829 534F 50,050 534N 51,239 530F 51,239 530N 50,543 528F 48,473 528N 48,721 526F 48,635 526N 51,345 520F 49,660 518F 49,896 518N 50,417 516 50,417 96Y 90,693 96T 89,974 94F 89,964 94N 90,187 H07-299 90,187 88F 89,948 88N 89,777 86F** 89,777 86N 90,335 84F 89,908 78 90,000 Notes: See Figure 3-4 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 75,780 8,738 64,590 8,015 34,384 6,198 49,662 7,198 39,890 6,485 63,896 7,948 76,634 8,811 120,089 11,425 114,398 . 11,026 76,582 8,581 82,989 8,987 121,526 11,298 120,857 11,480 10,642 4,712 9,780 4,680 10,999 4,796 12,374 4,879 12,578 5,384 19,859 5,564 20,053 5,570 19,593 5,568 17,307 5,499 13,021 5,356 12,367 5,327 11,782 5,309 10,566 5,303 16,337 5,454

18,279 5,518 3-10 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-10 Summary of D.C. Cook Unit 1 Normal Loads and Stresses for SI Line to Loop 4 Hot Leg Weld Location Axial Force Node (lbf) 221 50,888 218 49,409 214 49,409 2IOF 51,111 210N 49,869 208F 50,010 208N 51,062 204F 51,062 204N 50,493 202F 51,044 202N 48,794 200F 48,747 200N 51,117 194F 49,616 192F 49,410 191 50,488 190 50,488 148Y 90,764 148T 90,133 146F 90,116 146N 89,976 144F 89,976 144N 89,867 142F 89,867 142N 89,613 136 91,242 132 89,109 Notes: See Figure 3-3 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 83,729 9,209 73,134 8,451 41,948 6,575 43,187 6,789 34,989 6,194 50,262 7,124 61,527 7,888 99,383 10,165 94,367 9,817 83,671 9,218 90,867 9,467 102,708 10,175 99,185 10,158 7,782 4,537 9,608 4,630 11,173 4,812 18,415 5,248 19,399 5,594 11,489 5,320 12,102 5,337 14,162 5,392 16,083 5,450 16,886 5,468 15,280 5,420 16,092 5,430 18,199 5,584 30,612 5,842 3-11 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-11 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 1 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbf) (in-lbf) (psi) 402F 141,460 36,939 5,688 402N 141,520 29,875 5,578 400 50,417 29,028 5,880 398F 49,160 38,047 6,320 396F 49,408 41,113 6,524 396N 50,417 44,269 6,797 392F 50,417 57,042 7,565 392N 49,438 53,217 7,255 390F 50,139 57,111 7,547 388 49,331 61,933 7,770 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Table 3-12 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 2 Cold Leg Weld Location Axial Force Node (lbf) 400N 140,052 400F 139,916 404 48,812 408N 48,813 408F 50,287 410N 49,290 412 50,380 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbt) (psi) 55,872 5,937 46,864 5,789 44,641 6,688

75,277 8,531 70,037 8,336 66,775 8,058 73,888 8,576 3-12 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This st.atement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-13 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 3 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbf) (in-lbf) (psi) 158F 141,301 53,876 5,950 158N 141,375 43,159 5,783 156 50,271 41,688 6,630 150F 49,306 50,062 7,054 150N 49,549 45,600 6,806 148F 50,028 43,022 6,690 146 49,131 46,729 6,840 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Table 3-14 Summary ofD.c.*cook Unit 2 Normal Loads and Stresses for SI Line to Loop 4 Cold Leg Weld Location Axial Force Node .. (lbt) 294X 141,974 288F 50,872 288N 48,564 286F 50,897 284 50,947 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP. Moment Total Stress (in-lbf) (psi) 71,479 6,253 65,276 8,098 53,459 7,198 36,806 6,388 16,019 5,141 3-13 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-15 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 1 Hot Leg Weld Location Axial Force .Node (lbt) 181 51,407 178 50,122 174 50,123 170F 51,130 170N 49,891 168F 49,987 168N 51,100 164F 48,477 164N 50,492 162F 51,098 162N 51,142 156F 49,722 155 49,348 154N 50,285

150 50,285 148X 90,561 148T . ;-_ .. -.--:--"~-
-90,071 146F 90,054 146N 89,936 144F 89,936 144N 89,821 142F 89,821 142N 89,561 138F 8S,013 132 89,077 Notes: See Figure 3-6 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading \VC'AP-18309-NP Moment Total Stress (in-lbf) (psi) 117,539 11,285 103,745 10,350 56,258 7,494 47,551 7,053 39,773 6,484 50,593 7,142 61,397. 7,883 98,095 9,876 92,512

9,705 104,394 10,469 103,701 10,431 6,027 4,440 7,126 4,475 7,805 4,593 16,340 5,106 16,827 5,505 11,259 5,309 . 11,939 5,329 14,095 5,388 16,188 5,451 16,818 5,464 16,610 5,458 17,940 5,484 15,678
5,330 31,253 5,860 3-14 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRJETARY CLASS 3 Table 3-16 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 2 Hot Leg Weld Location Axial Force Node (lbf) 511 51,173 509 50,116 504 49,458 SOOP 51,388 SOON 49,830 498F 50,049 498N 51,380 494F 51,380 494N 50,555 492F 51,124 492N 50,858 490F 48,660 490N 48,165 484F 49,722 484N 50,276 482F 50,276 480F 49,469 480N 49,296 479 50,281 ) 96X 90,558 96T 89,894 94F 89,885 94N 90,238 90F 90,238 88F 90,144 88N 89,910 86F 89,910 86N 90,180 H06-299 89,852 78 90,205 Notes: See Figure 3-7 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 114,587 11,089 100,647 10,163 53,095 7,249 52,236 7,356 43,232 6,687 64,943 8,010 78,882 8,958 120,987 11,491 113,270 10,959 106,824 10,618 117,484 11,237 127,460 11,657 127,132 11,597 8,637 4,597 6,088 4,489 5,914 4,478 10,444 4,685 16,302 5,023 20,151 5,335 20,439 5,614 19,177 5,539 19,530 5,550 19,017 5,553 18,921 5,551 11,703 5,327 10,609 5,281 10,418 5,275 10,042 5,279 13,396 5,362 14,979 5,429 3-15 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-17 Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 3 Hot Leg Weld Location Axial Force Node ()bf) 550 51,346 546 49,230 ---540 50,346 536F 51,368 536N 49,832 534F 50,047 534N 51,267 530F 51,267 530N 50,545 528F 48,469 528N 48,736 526F 48,650 526N 51,367 520F 49,593 518F 49,627 518N 50,453 516 50,453 96Y 90,730 96T 89,894 94F 89,885 94N ---90,238 90F 90,238 88F 90,144 88N 89,910 86F 89,910 86N 90,180 H06-299 89,852 78 90,205 Notes: See Figure 3-7 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) -88,378 9,526 75,253 8,563 32)59 6,063 48,905 7,154 38,947 6,429 64,236 7,968 77,430 8,861 121,932 11,538 116,043 11,125 -78,623 8,704 85,323 9,129 123,071 11,392 122,526 11,582 10,438 4,695 10,029 4,673 12,290 4,876 14,469 5,008 14,827 5,454 19,177 5,539 19,530 5,550 19,017 5,553 18,921 5,551 11,703 5,327 10,609 5,28-I 10,418 5,275 10,042 5,279 13,396 5,362 14,979 5,429 ' 3-16 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) 1-! ---~---~-------WESTINGHOUSE NON-PROPRIETARY CLASS 3 3-17 Table 3-18 _ Summary ofD.C. Cook Unit 2 Normal Loads and Stresses for SI Line to Loop 4 Hot Leg Weld Location Axial Force Node (lbf) 221 51,356 218 49,415 214 50,163 210F 51,132 2ION 49,855 208F 50,023 208N 51,087 204F 51,087 204N 50,509 202F 51,074 202N -50,762 200F 48,750 200N 51,139 194F 49,973 192F 49,411 192N 50,492 188 50,492 148Y 90,769 148T 90,071 146F ---* 90,054 -146N 89,936 144F 89,936 144N 89,821 142F 89,821 142N 89,561 138F 88,013 132 89,077 Notes: See Figure 3-6 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment (in-lbf) 93,826 80,624 37,535 44,426 35,917 50,461 62,028 101,028 95,889 89,179 96,683 104,373 100,307 7,815 9,623 11,124 19,368 19,842 11,259 11,939 14,095 16,188 16,818 16;610 17,940 15,678 31,253 Total Stress (psi) 9,855 8,902 6,371 6,865 6,249 7,137 7,920 10,266 9,910 9,552 9,978 10,276 10,227 4,568 4,631 4,810 5,305 5,608 5,309 5,329 5,388 5,451 5,464 5,458 5,484 5,330 5,860 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-19 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 1 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbt) (in-lbt) (psi) 403F 141,892 179,151 7,956 402 142,077 164,448 7,730 398 50,921 157,807 13,668 Notes: See Figure 3-2 for piping layout. Axial force includes pressure. Table 3-20 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 2 Cold Leg Weld Location Axial Force Node (lbt) 400N 142,223 400F 142,400 406 51,240 Notes: See Figure 3-2 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 183,518 8,037 168,062 7,799 162,347 13,967 3-18 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-21 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 3 Cold Leg Weld Location Axial Force Node (lbf) 158F 142,168 158N 141,990 152 50,834 Notes: See Figure 3-2 for piping layout_ Axial force includes pressure. Moment Total Stress (in-lbf) (psi) 235,243 8,854 203,960 8,353 190,576 15,632 Table 3-22 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 4 Cold Leg Weld Location Axial Force Node (lbf) *294x 142,497 290 51,391 288N 51,085 286F 50,951 284 51,863 Notes: See Figure 3-2 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 109,287 6,871 106,093 10,596 96,236 9,978 80,705 9,032 67,914 8,338 3-19 January 2018 Revision 0 ***.This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon'its vaHdation) \VESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-23 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 1 Hot Leg

Weld Location Axial Force Node (lbf) 181 51,396 178 50,955 174 50,901 170F 51,911 170N 50,774 168F 50,374 168N 51,636 164F 51,341 164N 50,828 162F 51,471 162N 51,525 156F 51,419 155 51,330 .. 154N 52,302 152 52,292 148X 92,558 148T 93,990 146F 93,965 146N 93,348 144F 93,343 144N 94,240 142F 94,225 142N
92,710 136 93,358 132 92,704 Notes: See Figure 3-3 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP ... Moment Total Stress (in-lbf) (psi) 236,587 18,445 222,790 17,579 172,702 14,562 97,101 10,097 83,873 9,209 92,879 9,717 99,827 10,239 119,428 11,394 116,217 11,158 154,640 13,522 154,330 13,508 41,947 6,740 56,352 7,599 52,526 7,448 75,804 8,848 86,547 7,726 86,014 7,789 88,645 7,867 111,220 8,517 152,278 9,760 172,198 10,413 173,692 10,457 141,507 9,399 106,468 8,374 115,447 8,609 3-20 January 2018 Revision 0 ****This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-24 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 2 Hot Leg Weld Location Axial Force Node (lbf) 511 51,358 509 50,971 504 50,923 SOOP 52,122 SOON \ 50,891 498F 50,514 498N 51,897 494F 51,542 494N 50,899 492F 51,488 492N 51,462 490F 51,499 490N 51,767 484F 50,071 484N 51,033 482F 51,027 480F 50,330 480N 51,000 479 51,000 96X 91,269 96T 92,202 94F 92,191 94N 91,208 H07-299 91,188 88F-92,1-20 88N 91,706 86F 91,639 86N 91,654 84F 92,846 78 90,958 Notes: See Figure 3-4 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 242,447 18,795 231,313 18,093 178,790 14,930 104,804 10,578 89,945 9,583 103,751 10,383 114,808 11)61 138,845 12,578 134,131 12,242 150,114 13,251 159,665 13,824 171,561 14,542 174,832 14,761 16,290 5,086 19,495 5,357 20,548 5,420 21,314 5,409 28,613 5,903 36,092 6,353 36,826 6,150 113,064 8,510 115,326 8,577 102,308 8,129 81,280 7,491 91,964 7,866 88,649 7,743 97,989 8,022 86,656 7,680 46,951 6,543 64,533 6,971 3-21 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) . WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-25 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 3 Hot Leg Weld Location Axial Force Node (lbf) 550 51,593 546 51,229 540 51,171 536F 52,217 536N 50,921 534F 50,543 534N 51,836 : ,:~,,,,_;._

, '53DF 51,504 530N 50,962 528F 51,599 528N 51,309 526F 51,407 526N 51,769 520F 52,118 518F 50,567 518N 51,113 516 51,105 96Y 91,376 96T 92,202 94F 92,191
94N 91,208 H07-299 91,188 88F 92,120 88N 91,706 86F 91,639 86N 91,654 84F 92,846 ' 78 90,958 Notes: See Figure 3-4 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 240,235 18,681 216,269 17,209 171,146 14,491 107,015 10,719 92,504 9,740 111,613 10,858 120,710 11,511 143,183 12,836 141,958 12,718 115,786 11,196 127,870 11,899 177,463 14,890 182,247 15,207 23,588 5,693 19,945 5,346 45,145 6,907 75,601 8,738 81,843 7,519 113,064 8,510 *115,326 8,577 102,308 8,129 81,280 7,491 91,964 7,866 88,649 7,743 97,989 8,022 86,656 7,680 46,951 6,543 64,533 6,971 3-22 January 2018 Revision 0 .*** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-26 Summary ofD.C. Cook Unit 1 Faulted Loads and Stresses for SI Line to Loop 4 Hot Leg Weld Location Axial Force Node (lbf) 221 51,468 218 51,041 214 50,987 210F 51,905 210N 50,801 208F 50,401 208N 51,598 204F 51,292 204N 50,872 202F 51,478 202N 51,288 200F 51,339 200N 51,491 194F 51,721 192F 51,387 191 51,749 190 *. 51,739 148Y 92,006 148T 93,990 146F 93,965 146N 93,348 144F 93,343 144N 94,240 142F 94,225 142N 92,710 136 93,358 132 92,704 Notes: See Figure 3-3 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 234,437 18,322 217,436 17,264 168,947 14,343 98,298 10,169 85,362 9,300 94,785 9,834 101,127 -. 10,314 I 121,062 11,488 119,443 11,356 128,025. 11,922 . 139,402 12,591 152,541 13,385 154,_903 13,540 16,930 5,260 28,263 5,914 41,533 6,742 94,322 9,916 106,550 8,301 86,014 7,789 88,645 7,867 111,220 8,517 152,278 9,760 172,198 10,413 173,692 10,457 141,507 9,399 106,468 8,374 115,447 8,609 3-23 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-27 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 1 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbt) (in-lbf) (psi) 402F 142,272 186,610 8,088 402N 142,122 167,777 7,784 400 50,990 164,003 14,046 398F 50,906 79,898 8,980 396F 51,057 78,610 8,915 396N 50,900 77,904 8,860 392F 50,865 103,989 10,426 392N 50,509 103,782 10,384 390F 50,781 108,618 10,697 388 51,047 114,834 11,093 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Table 3-28 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 2 Cold Leg Weld Location Axial Force Node (lbf) 400N 142,665 400F 142,671 404 51,524 408N 51,372 408F 50,718 410N 50,961 412 51,306 Notes: See Figure 3-5 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 229,125 8,776 201,525 8,339 189,824 15,643 130,827 12,082 129,303 11,937 129,945 11,995 135,107 12,334 3-24 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-29

Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 3 Cold Leg Weld Location Axial Force Moment Total Stress Node (lbf) (in-lbf) (psi) 158F 142,515 276,095 9,514 158N 142,214 243,066 8,980 156 51,090 235,969 18,383 150F 50,972 117,263 11,233 150N 50,679 117,315 11,212 148F 50,575
124,252 11,621 146 51,246 129,438 11,988 Notes: See Figure 3-5 for piping layout. Axial force includes pressure.

Table 3-30 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 4 Cold Leg Weld Location

Axial Force Node (lbf) 294X
142,710 288F 51,609 288N 51,812 286F 51,674 284 52,214 Notes: See Figure 3-5 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 126,196 7,147 118,683 11,371 107,590 10,720 90,266 9,667 67,672 8,352 3-25 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added*by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-31 Summary of D.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 1 Hot Leg Weld Location Axial Force Node (lbt) 181 52,192 178 51,311 174 ... 51,016 170F 51,981 170N 50,749 168F 50,334 168N 51,639 164F 51,274 164N 50,892 162F 51,535 162N 51,559 156F 51,289 155 51,170 154N 51,925 150 51,915 148X 92,182 148T 93,376 146F 93,353 146N 93,009 144F 93,001 144N 93,838 142F 93,820 142N 92,168 .. 138F 93,185 132 92,707 Notes: See Figure 3-6 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 288,856 21,654 268,518 20,359 193,759 15,838 109,528 10,851 95,873 9,928 99,233 10,096 103,828 10,480 123,698 11,645 120,666 11,431 168,720 14,374 168,758 ' 14,379 37,504 6,462 49,694 7,185 46,119 7,032 74,882 8,761 79,741 7,499 68,413 7,222 69,602 7,257 85,005 7,704 121,875 8,820 139,550 9,402 149,270 9,695 123,274 8,817 88,104 7,808 106,504 8,339 3-26 January 2018 Revision 0 *** This.record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) -~I WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-32 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for

SI Line to Loop 2 Hot Leg Weld Location Axial Force Node (lbf) 511 51,890 509 51,237 504 , 51,021 SOOP 52,210 SOON 50,890 498F 50,493 498N 51,934 494F 51,560 494N 50,933 492F 51,525 492N 51,479 490F 51,545 490N 51,808 484F 50,180 484N 51,096 482F 51,078 480F 50,292 480N 51,043 479 51,043 96X 91,315 96T 92,030 94F 92,019 94N 91,273 90F 91,261 88F 93,068 88N 91,869 86F 91,827 86N 92,520 H06-299 92,489 78 -91,008 Notes: See Figure 3-7 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbt) (psi) 280,839 21,148 263,700 20,063 188,612 15,529 110,594 10,934 95,640 9,926 109,017 J0,698 118,607 11,393 142,341 12,790 137,653 12,456 153,238 13,442 166,255 14,222 180,534 15,086 185,315 15,395 15,866 5,069 19,658 5,372 21,432 5,478 22,414 5,472 29,615 5,967 37,398 6,435 38,171 6,193 124,115 8,835 125,845 8,886 111,297 8,405 72,981 7,244 88,978 7,828 88,845 7,758 107,406 8,318 105,222 8,290 52,818 6,701 67,429 7,062 3-27 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) - WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 3-33 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 3 Hot Leg Weld Location Axial Force Node (lbf) 550 52,154 546 51,453 540 51,238 536F 52,250 536N 50,888 534F 50,488 534N 51,878 530F 51,540 530N 50,985 528F 51,647 528N 51,382 526F 51,479 526N 51,806 520F 52,308 518F 50,194 518N 51,068 516 51,063 96Y 91,336 96T 92,030 94F 92,019 94N 91,273 90F 91,261 88F 93,068 88N 91,869 86F 91,827 86N 92,520 H06-299 92,489 78 91,008 Notes: See Figure 3-7 for piping layout. Axial force includes pressure. Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 262,513 20,067 236,528 18,446 171,927 14,543 112,160 11,031 97,253 10,023 116,111 11,124 124,720 11,756 148,615 13,166 146,608 12,999 125,244 11,769 138,602 12,550 188,600 --15,566 194,538 15,950 24,770 5,779 18,533 5,231 45,104 6,901 79,207 8,952 85,935 7,640 124,115 8,835 125,845 8,886 lU,297 8,405 72,981-7,244 88,978 7,828 88,845 7,758 107,406 8,318 105,222 8,290 52,818 6,701 67,429 7,062 3-28 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table3-34 Summary ofD.C. Cook Unit 2 Faulted Loads and Stresses for SI Line to Loop 4 Hot Leg Weld Location Axial Force Node (lbf) 221 52,162 218 51,335 214 51,066 210F 51,969 210N 50,837 208F 50,436 208N 51,657 204F 51,333 204N 50,912 202F 51,529 202N 51,304 200F 51,377 200N 51,542 194F 51,444 192F 51,062 192N 51,531 188 51,520 148Y 91,787 148T 93,376 146F 93,353 146N 93,009 144F 93,001 .* 144N 93,838 142F 93,820 142N 92,168 138F 93,185 132 92,707 Notes: See Figure 3-6 for piping layout. Axial force includes pressure.

Pipe Geometry and Loading WCAP-18309-NP Moment Total Stress (in-lbf) (psi) 258,524 19,828 238,590 18,561 169,236 14,367 103,092 10,463 89,464 9,550 96,334 9,930 102,815 10,420 124,048 11,671 .-,::.;-.,* . ii,539 122,433 138,325 12,546 149,320 13,189 156,054 13,600 157,825 13,720 18,730 5,345 23,137 5,579 33,933 6,267 85,439 9,364 90,431 7,801 68,413 7,222 69,602 7,257 85,005 7,704 121,875 8,820 139,550 9,402 149,270 9,695 123,274 8,817 88,104 7,808 106,504 8,339 3-29 January 2018 Revision 0 . *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) \ WESTINGHOUSE NON-PROPRIETARY CLASS 3 Cold Leg Safetv Injection (through the Accmnulato.r li1le ): .. -+<}--Bot Leg S~fetvinjecfion: t10 a> .-J ...., ... ----t::::._ -r---1<:J-* $1-Hl'...-IIJ Figure 3-1 D.C. Cook Units 1 and 2 Typical Piping Layout for SI lines (Note: division between evaluation segments SI-HL-I and SI-HL-II occurs shortly beyond the check valves, where the temperature transition occurs, as defined in the piping analyses) 3-30 Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3-2 D.C. Cook Unit 1 Cold Leg SI Line Layout Showing Weld Locations with Node Points -Loops 1 through 4 3-31 (Note: gray lines represent the Accumulator lines which are evaluated in a separate report) Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) LOoP _. HOTl.£G WESTINGHOUSE NON-PROPRIETARY CLASS 3 --, .. .... ... LOOP 1 HOT UC Figure 3-3 D.C. Cook Unit 1 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 1 and 4 Pipe Geometry and Loading WCAP-18309-NP 3-32 *** January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3-4 D.C. Cook Unit 1 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 2 and 3 Pipe Geometry and Loading WCAP-18309-NP 3-33 LOOP 2 HOTL£G January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3-5 D.C. Cook Unit 2 Cold Leg SI Line Layout Showing Weld Locations with Node Points -Loops 1 through 4 3-34 (Note: gray lines represent the Accumulator lines which are evaluated in a separate report) Pipe Geometry and Loading WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on .1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 _ ... \_

RC-HOT LEC LOOP~ Figure 3-6 D.C. Cook Unit 2 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 1 and 4 Pipe Geometry and Loading WCAP-18309-NP 3-35 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 3-7 D.C. Cook Unit 2 Hot Leg SI Line Layout Showing Weld Locations with Node Points -Loops 2 and 3 Pipe Geometry and Loading WCAP-18309-NP 3-36 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 4-1 4.0 MATERIAL CHARACTERIZATION 4.1 SI LINE PIPE MATERIAL AND WELD PROCESS The material type of the SI lines for D.C. Cook Units 1 and 2 is either A376 TP316 for seamless pipes or A403 WP 316 for fittings. This is a wrought product of the type used for the piping in several PWR plants. The welding processes used are Shielded Metal Arc Weld (SMAW) and Submerged Arc Weld (SAW). In the following sections the tensile properties of the materials are presented for use in the Leak-Before-Break analyses.

4.2 TENSILE

PROPERTIES Certified Materials Test Reports (CMTRs) with mechanical properties were not readily available for the D.C. Cook Units 1 and 2 SI lines. Therefore, ASME Code mechanical properties were used to establish the tensile properties for the Leak-Before-Break analyses. For the A376 TP316 (seamless pipe) and A403 WP316 (wrought fittings) material types, the representative properties at operating temperatures are established from the tensile properties given by Section II of the 2007 ASME Boiler and Pressure Vessel Code. Code tensile properties at temperatures for the operating conditions considered in this LBB analysis were obtained by linear interpolation of tensile properties provided in the Code. Material modulus of elasticity was also interpolated from ASME Code values for the operating temperatures considered, and Poisson's ratio was taken as 0.3. The yield strengths, ultimate strengths, and elastic moduli for the pipe material at applicable operating temperatures are tabulated in Table 4-1. 4.3 REFERENCE 4-1 ASME Boiler and Pressure Vessel Code Section II, 2007 Edition through 2008 Addenda. Material Characterization WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) . WESTINGHOUSE NON-PROPIUETARY CLASS.3 4-2 Table 4-1 Material Properties for Operating Temperature Conditions on D.C. Cook Units 1 and 2 SI Lines Segment SI-HL-I SI-CL-I SI-HL-II SI-HL-III Material Characterization WCAP-18309-NP Operating Ultimate Temperature Strength (OF) (psi) 618 71,800 120 75,000 Yield Strength (psi) 18,756 28,960 Elastic Modulus (psi) 25,210,000 27,992,308 -January 2018 Revision 0 ***This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added.by the PRIME.system upon its validation)

, WESTINGHOUSE NON-PROPRIETARY CLASS 3 5-1 5.0 CRITICAL LOCATIONS

5.1 CRITICAL

LOCATIONS The Leak-Before-Break (LBB) evaluation margins are to be demonstrated for the critical locations (governing locations). Such locations are established based on the loads (Section 3.3) and the material properties established in Section 4.2. These locations are defined below for the D.C. Cook SI lines. Critical Locations for the SI'lines: All the welds in the SI lines are fabricated using the Shielded Metal Arc Weld (SMAW) or Submerged Arc Weld (SAW) processes. The pipe material type is A3 7 6 TP316 or A 403 WP3 l 6. The governing locations were established on the basis of the pipe geometry, welding process, material type, operating temperature, operating pressure, and the highest faulted stresses at the welds. Table 5-1 shows the highest faulted stress and the corresponding weld location node for each welding process type in each segment of the hot leg and cold leg SI lines, enveloping both D.C. Cook Units 1 and 2. Definition of the piping segments and the corresponding operating pressure and temperature parameters are from Table 3-1, Table 3-2, and Figure 3-l. Figures 5-1 through 5-4 show the locations of the critical welds. The weld naming convention used in this report is as follows: <analysis node number> _U<Unit 1 or 2>L<Loop 1/2/3/4> "L14" indicates the piping where SI lines from Loop 1 and Loop 4 have joined together. Critical Locations WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 5-2 ---Table 5-1 Critical Analysis Location for Leak-Before-Break ofD.C. Cook Units 1 and 2 SI Lines Segment Pipe Size 10-inch -SI-CL-I 6-inch SI-HL-I 6-inch SI-HL-II 6-inch SI-HL-III 8-inch Critical Locations WCAP-18309-NP --I Welding Operating Process Pressure (psig) SAW 2,235 SMAW 2,235 SAW -2,235 SMAW 2,235 SAW 2,235 SMAW 2,235 SAW 2,235 SMAW 2,235 SAW 2,235 Operating Maximum Temperature Faulted Stress (OF) (psi) 120 9,514 120 18,383 120 12,082 618 21,654 618 11,031 --120 15,950 120 15,566 120 9,399 120 10,457 Weld Location Node 158F U2L3 156 U2L3 408N U2L2 181 U2Ll 536F U2L3 526N U2L3 526F U2L3 142N U1Ll4 142F U1L14 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM._(_This statement was added by the PRIME-system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 .Critical Location:

Segment SI-CL-I 10-inch SAW weld Critical Location: Segment SI-CL-I 6-inch SMAW weld Critical Location: Segment SI-CL-I 6-inch SAW weld Figure 5-1 D.C. Cook Unit 2 Cold Leg SI Line Critical Weld Locations Critical Locations WCAP-18309-NP 5-3 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Critical Location: Segment SI-HL-III 8-inch SMAW weld Critical Location: Segment SI-HL-III 8-inch SAW weld 5-4 Figure 5-2 D.C. Cook Unit 1 Hot Leg SI Line Loops 1 and 4 Critical Weld Locations Critical Location: Segment SI-HL-1 6-inch SMAW weld ITO Figure 5-3 D.C. Cook Unit 2 Hot Leg SI Line Loop 1 Critical Weld Locations Critical Locations WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Critical Location: Segment SI-HL-II 6-inch SAW weld Critical Location: Segment SI-HL-II 6-inch SMAW weld 5-5 Figure 5-4 D.C. Cook Unit 2 Hot Leg SI Line Loop 3 Critical Weld Locations Critical Locations WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the.PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 6-1 6.0 LEAK RATE PREDICTIONS

6.1 INTRODUCTION

The purpose of this section is to discuss the method which is used to predict the flow through postulated through-wall cracks and present the leak rate calculation results for through-wall circumferential cracks. 6.2 GENERAL CONSIDERATIONS The flow of hot pressurized water through an opening to a lower back pressure causes flashing which can result in choking. For long channels where the ratio of the channel length, L, to hydraulic diameter, DH, (L/DH) is greater than [ t'c,e 6.3 CALCULATION METHOD The basic method used in the leak rate calculations is the method developed by [ ]a,c,e The flow rate through a crack was calculated in the following manner. Figure 6-1 (from Reference 6-2) was used to estimate the critical pressure, Pc, for the SI line enthalpy condition and an assumed flow. Once Pc was found for a given mass flow, the [ ]a,c,e was found from Figure 6-2 (taken from Reference 6-2). For all cases considered, [ ]a,c,e therefore, this method will yield the two-phase pressure drop due to momentum effects as illustrated in Figure 6-3, where P 0 is the operating pressure. Now using the assumed flow rate, G; the frictional pressure drop can be calculated using where the friction factor f is determined using the [ was obtained from fatigue crack data on stainless steel samples. these calculations was [ rc,e (6-1) rc,e The crack relative roughness, E, The relative roughness value used in The frictional pressure drop using Equation 6-1 is then calculated for the assumed flow rate and added to the [ ]a,c,e to obtain the total pressure drop from the primary syst~in to the atmosphere. Leak Rate Predictions WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM,. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3

6-2 That is, for the SI lines: Absolute Pressure -14.7 = [ J"'c,e (6-2) for a given assumed flow rate G. If the right-hand side of Equation 6-2 does not agree with the pressure difference between the SI line and the atmosphere, then the procedure is repeated until Equation 6-2 is satisfied to within an acceptable tolerance which in tum leads to a flow rate value for a given crack size. For the single phase cases with lower temperature, leakage rate is calculated by the following equation (Reference 6-4) with the crack opening area obtained by the method from Reference 6-3. Q = A (2gAf>/kp

)°-5 ft 3 /sec; (6-3) where, L'.lP = pressure difference between stagnation and back pressure (lb/ff), g = acceleration of gravity (ft/sec2), p = fluid density ~t at~ospheric pressure (lb/ft\ k = friction loss including passage loss, inlet and outlet of the through-wall crack, A= crack opening area (ft2). 6.4 LEAK RATE CALCULATIONS Leak rate calculations were made as a function of crack length at the governing locations previously identified in Section 5.1. The normal operating loads of Table 3~3 through Table 3-10 (for Unit 1), and Table 3-11 through Table 3-18 (for Unit 2), were applied in these calculations. The crack opening areas were estimated using the method of Reference 6-3 and the leak rates were calculated using the formulation desc-{ibed above. The material properties of Section 4.2 (see Table 4-1) were used for these calculations. The flaw sizes to yield a leak rate of 8 gpm were calculated at the governing locations and are given in Table 6-1 for D.C. Cook Units 1 and 2. The flaw sizes, so determined, are called leakage flaw sizes. The D.C. Cook Units 1 and 2 RCS pressure boundary leak detection system meets the intent of Regulatory Guide 1.45 and meets a leak detection capability of 0.8 gpm. Thus, to satisfythe margin of 10 on the leak rate, the flaw sizes (leakage flaw sizes) are determined which yield a leak rate of 8 gpm. Leak Rate Predictions WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 6-3

6.5 REFERENCES

6-1 [ ]a,c,e 6-2 M. M. El-Wakil, "Nuclear Heat Transport, International Textbook Company," New York, N.Y, 1971. 6-3 Tada, H., "The Effects of Shell Corrections on Stress Intensity Factors and the Crack Opening Area of Circumferential and a Longitudinal Through-Crack in a Pipe," Section II-1, NUREG/CR-3464, September 1983. 6-4 Crane, D. P., "Handbook of Hydraulic Resistance Coefficient," Flow of Fluids through Valves, Fittings, and Pipe by the Engineering Division of Crane, 1981, Technical Paper No. 410. Leak Rate Predicti.ons WCAP-18309-NP January 2018 Revision 0 *** This record was final approved 6n 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) Table 6-1 Segment SI-CL-I SI-HL-I SI-HL-11 SI-HL-111 Leak Rate Predictions WCAP-18309-NP WESTINGHOUSE NON-PROPRIETARY CLASS 3 Flaw Sizes Yielding a Leak Rate of 8 gpm for the D.C. Cook Units 1 and 2 Sllines Pipe Size Welding Weld Location Leakage Flaw Size Process Node (in) IO-inch SAW 158F U2L3 5.25 SMAW 156 U2L3 4.14 , 6-inch SAW 408N U2L2 3.66 SMAW 181 U2Ll 2.93 6-inch SAW 536F U2L3 3.96 SMAW 526N U2L3 3.06 6-inch SAW 526F U2L3 3.10 8-1nch SMAW 142N U1L14 5.00 SAW 142F U1L14 5.01 6-4 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 6-5 a,c,e N-,:: -! -*~* -STAGNATION ENTHALPY no2 Btu/lbt Figure 6-1 Analytical Predictions of Critical Flow Rates of Steam-Water Mixtures Leak Rate Predictions WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

Figure 6-2 [ Leak Rate Predictions WCAP-18309-NP WESTINGHOUSE NON-PROPRIETARY CLASS 3 LENGTH/DIAMETER RATIO (L/0) J3*c,e Pressure Ratio as a Function of LID 6-6 a,c,e January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 [ Figure 6-3 Idealized Pressure Drop Profile Through a Postulated Crack Leak Rate Predictions WCAP-18309-NP 6-1 a.c.e January 2018 Revision 0 .... This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 7-1 7.0 FRACTURE MECHANICS EVALUATION 7.l GLOBAL FAILURE MECHANISM Determination of the conditions which lead to failure in stainless steel should be done with plastic fracture methodology because of the large amount of deformation accompanying fracture. One method for predicting the failure of ductile material is the plastic instability method, based on traditional plastic limit load concepts, but accounting for strain hardening and taking into account the presence of a flaw. The flawed pipe is predicted to fail when the remaining net section reaches a stress level at which a plastic

hinge is formed. The stress level at which this occurs is termed as the flow stress. The flow stress is generally taken as the average of the yield and ultimate tensile strength of the material.

at the temperature of interest. This methodology has been shown to be applicable to ductile piping through a large number of experiments and will be used here to predict the critical flaw size in the SI line piping. The failure criterion h~.been obtained by requiring equilibrium of the section containing the flaw (Figure 7-1) when loads are applied. The detailed development is provided in Appendix A for a through-wall circumferential flaw in a pipe with internal pressure, axial force, and imposed bending moments. The limit moment for such a pipe is given by: [ ] a,c,e where: r* The analytical model described above accurately accounts for the piping internal pressure as well as imposed axial force as they affect the limit moment. Good agreement was found between the analytical predictions and the experimental results (Reference 7-1 ). For application of the limit load methodology, the material, including consideration of the configuration, must have a sufficient ductility and ductile tearing resistance to sustain the limit load. Fracture Mechanics Evaluation WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 7-2 7.2 LOCAL FAILURE MECHANISM The local mechanism of failure is primarily dominated by the crack tip behavior in terms of crack-tip blunting, initiation, extension and finally cracks instability. The local stability will be assumed if the crack does not initiate at all. It has been accepted that the initiation toughness measured in terms of Ire from a I-integral resistance curve is a material parameter defining the crack initiation. If, for a given load, the calculated I-integral value is shown to be less than the Ire of the material, then the crack will not initiate. Stability analysis using this approach is performed for a selected location.

7.3 RESULTS

OF CRACK STABILITY EVALUATION A stability analysis based on limit load was performed. Shop welds and field welds for the SI lines of D.C. Cook Units 1 and 2 utilize the SMAW or SAW weld processes. The "Z" correction factor (References 7-2 and 7-3) are as follows: Z = 1.15 [1.0 + 0.013 (OD-4)] for SMAW Z = 1.30 [1.0 + 0.010 (OD-4)] for SAW where OD is the outer diameter of the pipe in inches. The Z-factors for the SMAW and SAW were calculated for the critical locations, using the pipe outer diameter (OD) for each respective segment of the SI lines. The applied faulted loads of Table 3-19 through Table 3-26 (for Unit 1) and Table 3-27 through Table 3-34 (for Unit 2) were increased by the Z factor and critical flaw size was calculated by flaw stability under the respective loading conditions for each governing location. Table 7-1 summarizes the results of the stability analyses based on limit load for the governing locations on D.C. Cook Units 1 and 2. The associated leakage flaw sizes (from Table 6-1) are also presented in the same table. Additionally, elastic-plastic fracture mechanics (EPFM) I-integral analysis for through-wall circumferential crack in a cylinder is performed for select locations using the procedure in the EPRI Fracture Mechanics Handbook (Reference 7-4). Table 7-1 shows the results of this analysis.

7.4 REFERENCES

7-1 Kanninen, M. F., et. al., "Mechanical Fracture Predictions for Sensitized Stainless Steel Piping with Circumferential Cracks," EPRI NP-192, September 1976. 7-2 Standard Review Plan; Public Comment Solicited; 3.6.3 Leak-Before-Break Evaluation Procedures; Federal RegisterNol. 52, No. 167/Friday, August 28, 1987/Notices, pp. 32626-32633. 7-3 NUREG-0800 Revision 1, March 2007, Standard Review Plan: 3.6.3 Leak-Before-Break Evaluation Procedures. 7-4 Kumar, V., German, M.D. and Shih, C. P., "An Engineering Approach for Elastic-Plastic Fracture Analysis," EPRI Report NP-1931, Project 1237-1, Electric Power Research Institute, July 1981. ,, Fracture Mechanics Evaluation WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 7-1 Flaw Stability Results for the D.C. Cook Units 1 and 2 SI Lines Based on Limit Load and EPFM Segment Pipe Size Welding Weld Location Process Node 10-inch SAW 158F U2L3 SI-CL-I 6-inch SMAW 156 U2L3 SAW 408N U2L2 SI-HL-I 6-inch SMAW 181 U2Ll. SAW 536F U2L3 SMAW 526N U2L3 SI-HL-II 6-inch SAW 526F U2L3 SMAW 142N U1L14 SI-HL-III 8-inch SAW 142F U1L14 Note: 1 Based on the methodology in Section 7.2 Fracture Mechanics Evaluation WCAP-18309-NP Critical Flaw Size (in) 14.47 8.28(!) 8.46 6.31 8.22 8.03 7.67 12.20 11.36 7-3 Leakage Flaw Size (in) 5.25 4.14 3.66 2.93 3.96 3.06 3.10 5.00 5.01 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) .

WESTINGHOUSE NON-PROPRIETARY CLASS 3 Figure 7-1 [ Fracture Mechanics Evaluation WCAP-18309-NP Neutral Axis ]8,c,* Stress Distribution 7-4 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)

WESTINGHOUSE NON-PROPRIETARY CLASS 3 8-1 8.0 ASSESSMENT OF FATIGUE CRACK GROWTH The fatigue crack growth (FCG) analysis is not a requirement for the LBB analysis (see References 8-1 and 8-2) since the LBB analysis is based on the postulation of a through-wall flaw, whereas the FCG analysis is performed based on the surface flaw. In addition Reference 8-3 has indicated that, "the Commission deleted the fatigue crack growth analysis in the proposed rule. This requirement was found to be unnecessary because it was bounded by the crack stability analysis." Also, since the growth of a flaw which leaks 8 gpm would be expected to be minimal between the time that leakage reaches 8 gpm and the time that the plant would be shutdown; therefore, only a limited number of cycles would be expected to occur.

8.1 REFERENCES

8-1 Standard Review Plan; Public Comment Solicited; 3.6.3 Leak-Before-Break Evaluation Procedures; Federal RegisterNol. 52, No. 167/Friday, August 28, 1987/Notices, pp. 32626-32633. 8-2 NUREG-0800 Revision 1, March 2007, Standard Review Plan: 3.6.3 Leak-Before-Break Evaluation Procedures. 8-3 Nuclear Regulatory Commission, 10 CFR 50, Modification of General Design Criteria 4 Requirements for Protection Against Dynamic Effects of Postulated Pipe Ruptures, Final Rule, Federal . RegisterNol. 52, No. 207/Tuesday, October 27, 1987/Rules and Regulations, pp. 41288-41295. Assessment of Fatigue Crack Growth WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIBTARY CLASS 3 9-1 9.0 ASSESSMENT OF MARGINS The results of the leak rates of Section 6.4 and the corresponding stability evaluations of Section 7.3 are used in performing the assessment of margins. Margins are shown in Table 9-1 for the governing locations on D.C. Cook Units 1 and 2. All the LBB recommended margins are satisfied. In summary, margins at the critical locations are relative to: l. Flaw Size -Using faulted loads obtained by the absolute sum method, a margin of 2 or more exists between the critical flaw and the flaw having a leak rate of 8 gpm (the leakage flaw). 2. Leak Rate -A margin of 10 exists between the calculated leak rate from the leakage flaw and the plant leak detection capability of 0.8 gpm. 3. Loads -At th_e critical locations the leakage flaw was shown to be stable using the faulted loads obtained by the absolute sum method (i.e., a flaw twice the leakage flaw size is shown to be stable; hence the leakage flaw size is stable). A margin of 1 on loads using the absolute summation of faulted load combinations is satisfied. Assessment of Margins WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added _by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Table 9-1 Leakage Flaw Sizes, Critical Flaw Sizes, and Margin for the D.C. Cook Units 1 and 2 SI Lines Welding Weld Location Critical Segment Pipe Size Process Node Flaw Size (in) IO-inch SAW 158F U2L3 14.47 SI-CL-I SMAW 156 U2L3 8.28(!) 6-inch SAW 408N U2L2 8.46 SMAW 181 U2Ll 6.31 SI-HL-I 6-inch SAW 536F U2L3 8.22 SMAW 526N U2L3 8.03 SI-HL-II 6-inch SAW 526F U2L3 7.67 SMAW 142N U1L14 12.20 SI-BL-III 8-inch SAW 142F Ul114 11.36 Note: 1 Margin of2.0 is demonstrated based on the methodology in Section 7.2 Assessment of Margins WCAP-18309-NP Leakage Flaw Size (in) 5.25 4.14 3.66 2.93 3.96 3.06 3.10 5.00 5.01 9-2 Margin 2.8 >2.Q(l) 2.3 2.2 2.1 2.6 2.5 2.4 2.3 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 10-1

10.0 CONCLUSION

S This report justifies the elimination of SI line breaks from the structural design basis for D.C. Cook Units 1 and 2 as follows: a. Stress corrosion cracking is precluded by use of fracture resistant materials in the piping system and controls on reactor coolant chemistry, temperature, pressure, and flow during normal operation. Note: Alloy 82/182 welds do not exist at the D.C. Cook Units 1 and 2 SI lines. b. Water hammer should not occur in the SI line piping because of system design, testing, and operational considerations.

c. The effects of low and high cycle fatigue on the integrity of the SI line piping are negligible.

d. Ample margin exists between the leak rate of small stable flaws and the capability of the D.C. Cook Units 1 and 2 reactor coolant system pressure boundary leakage detection systems. e. Ample margin exists between the small stable flaw sizes of item ( d) and larger stable flaws. f. Ample margin exists in the material properties used to demonstrate end-of-service life (fully aged) stability of the critical flaws. For the critical locations, postulated flaws will be stable because of the ample margins described ind, e, and f above. Based on loading, pipe geometry, welding process, and material properties considerations, enveloping critical (governing) locations were determined at which Leak-Before-Break crack stability evaluations were made. Through-wall flaw sizes were postulated which would cause a leak at a rate often (10) times the leakage detection system capability of the plant. Large margins for such flaw sizes were demonstrated against flaw instability.

Finally, fatigue crack growth assessment was shown not to be an issue for the SI line piping. Therefore, the Leak-Before-Break conditions and margins are satisfied for D.C. Cook Units 1 and 2 SI line piping. It is demonstrated that the dynamic effects of the pipe rupture resulting from postulated breaks in the SI line piping need not be considered in the structural design basis ofD.C. Cook Units 1 and 2. Conclusions WCAP-18309-NP January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) Appendix A: Limit Moment WCAP-18309-NP WESTINGHOUSE NON-PROPRIETARY CLASS 3 APPENDIX A: LIMIT MOMENT ] a,c,e A-1 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WESTINGHOUSE NON-PROPRIETARY CLASS 3 Cl) cS.,-------------------------, cg Figure A-1 Pipe with a Through-Wall Crack in Bending Appendix A: Limit Moment WCAP-18309-NP A-2 January 2018 Revision 0 *** This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation) WCAP-18309-NP Revision 0 Proprietary Class 3 **This page was added to the quality record by the PRIME system upon its validation and shall not be consid.ered in the page numbering of this documenl** Author Approval Johnson Eric D Jan-17-2018 14:48:08 Reviewer Approval Wiratmo Mamo Jan-17-2018 15:32:24 Manager Approval Leber Benjamin A Jan-18-2018 09:38:47 Files approved on Jan-18-2018

- - This record was final approved on 1/18/2018 9:38:47 AM. ( This statement was added by the PRIME system upon its validation)}}

ML18334A270

Contents

Text

1.0 INTRODUCTION

1.1 PURPOSE

1.3 REFERENCES

2.5 REFERENCES

3.4 REFERENCES

4.2 TENSILE

5.1 CRITICAL

6.1 INTRODUCTION

6.5 REFERENCES

7.3 RESULTS

7.4 REFERENCES

8.1 REFERENCES

10.0 CONCLUSION

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ML18334A270

Text

1.0 INTRODUCTION

1.1 PURPOSE

1.3 REFERENCES

2.5 REFERENCES

3.4 REFERENCES

4.2 TENSILE

5.1 CRITICAL

6.1 INTRODUCTION

6.5 REFERENCES

7.3 RESULTS

7.4 REFERENCES

8.1 REFERENCES

10.0 CONCLUSION

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