RS-15-236, Areva Calculation 32-9244434-000, Revision 0, Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis.

Areva Calculation 32-9244434-000, Revision 0, Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis.

ML15259A051
Person / Time
Site:	Byron, Braidwood
Issue date:	07/29/2015
From:	Noronha S, Riordan T AREVA
To:	Exelon Generation Co, Office of Nuclear Reactor Regulation
Shared Package
ML15259A048	List: ML15259A049 ML15259A050 RS-15-236, Areva Calculation 32-9244389-000, Revision 0, Byron/Braidwood RVCH Nozzle Idtb Repair Weld Anomaly. RS-15-236, Areva Calculation 32-9244434-000, Revision 0, Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis. RS-15-236, Braidwood Station, Units 1 and 2 & Byron Station, Units 1 and 2 - Head Penetrations with Nozzles Having Pressure-Retaining Partial-Penetration J-Groove Welds
References
RS-15-236 32-9244434, Rev. 0
Download: ML15259A051 (109)

Text

SATTACHMENT 5 Areva Calculation, "Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis (32-9244434)," Revision 0 NON-PROPRIETARY

Controlled Document 0402-01-F01 (Rev. 019, 6/25/2015)

A CALCULATION

SUMMARY

SHEET (CSS)

ARE VA Document No. 32 -9244434 -000 Safety Related: I~lYes El No Title Byron and Braidwood RVCH Nozzie As-Left J-Groove Analysis - Non Proprietary PURPOSE AND

SUMMARY

OF RESULTS:

PURPOSE:

Due to concerns that Control Rod Drive Mechanism (CRDM), core exit thermocouple (CETC), and reactor vessel level indication system (RVLIS) nozzle penetration degradation may have occurred in the Reactor Vessel Closure Heads (RVCHs) at Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, Exelon Generation Company, LLC (Owner) contracted AREVA to create a modification to repair these nozzles as a contingency. In the event that a repair is necessary, an ID temper bead weld repair procedure has been developed wherein the lower portion of the nozzle is removed by a boring procedure and the remaining portion is welded to the low alloy steel reactor vessel head above the original Alloy 82/1 82 J-groove attachment weld. Per Reference [1], fracture mechanics analysis must be performed to justify the worst-case flaw(s) remaining in the original nozzle-to-RVCH weld (as-left J-groove weld) at the worst-case location(s)

The purpose of this calculation is to perform a fracture mechanics analysis of the worst-case flaws in the as-left J-groove weld at the worst-case penetration location. This analysis considers the worst-case nozzle location and utilizes material properties which bound the properties of all four units.

SUMMARY

OF RESULTS:

A fatigue crack growth and fracture mechanics evaluation of the worst-case flaws in the as-left J-groove weld and buttering at the worst-case penetration location has been performed. Based on a combination of linear elastic and elastic-plastic fracture mechanics the postulated flaws are shown to be acceptable for the remaining life utilizing the safety factors in Table 1-1, and the lower bound J-R Curve from Regulatory Guide 1.161.

Limitation: The minimum metal temperature for performing a Hydrostatic test at any time after an IDTB repair has been made is [ ]

The following table summarizes the total pages contained in this document.

ISection~e Main Body A endix A 1A endix B56Total If the computer software used herein is not the latest version per the EASI list, THE DOCUMENT CONTAINS AP 0402-01 requires that justification be provided. ASSUMPTIONS THAT SHALL BE THE FOLLOWING COMPUTER CODES HAVE BEEN USED INTHIS DOCUMENT: VERIFIED PRIOR TO USE CODENERSION/REV CODENERSION/REV [] Yes ANSYS 14.5.7 []NO Page 1 of 104

Controlled Document 040_2-01-F01 (Rev, 019, 6125/2015)

A AREVA Document No. 32-9244434-0.00 Byron and Braldwood R~VCH Nozzle As-Left J-GrooVs Analysis - Non Proprietary Review Method: i[ tDeign Revieow (PetaUed Che~k)

[]AlAtere.ate 'Calcul~ation Signature BiQck

/A

,.P/R Name eand Title and Pageg/Sections (printed or typ~ed) signatur'e LPILR Date Prepared/ReviewediApproved om. Riordan ,'" -,..- ' P All ......

" .e.e..o~na

?AI 'At.. -. "..

Tim Wig~r..* . ..

• A / '7, AlU Engineering. . * - ,

Notes' P/R/A designates Preparer (p), Reviewer(R), Approver,(A);:

LP/LR desliiates Leaid.Pieparr IL.P), Lead .Reyiewer(LR0 Ini revieWing .*nd .app-roving the Ihittia! rte.!e.* :(Re., .000), the lead revibWe'r/a~ppoV~er sin I deslgnate 'A!!' in:

pageslsectionts reviewed/approved.

• In revie~wing and~ approving *rovisions,. the lead preparer and lead reviewer *shall use 'All' in the pages/sections.

revl*we.d/approved., iA.' mean.* *tht tJ* °ehanges and .the .eft'e~t~tf* the~echanges .on the entire dopument have been Vievtet.d/approed. It does .not lilatn that.the !oad j.eiwer*/approver has reviewed/a~pproved all the .pages of the Project.ManaflerApproval of Customer References (N/A if niot applicabie)

Name Tilie ....

(printed. or typed) (printed or typed) S8ignature Date

.N/A Page 2

Controlled Document A 0402-01 -F01 (Rev. 019, 6/25/2015)

AR EVA Document No. 32-9244434-000 Byron and Braidwood 'RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Signature Block (Continued)

Mentoring Information (not required per 0402-01)

Name Title Mentor to:

(printed or typed) (printed or typed) (PIR) Signature Date N/A 1-h h Page 3

Controlled Document A 0402-01-F01 (Rev. 019, 6/25/2015)

AREEVA .Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Record of Revision Revision PageslSectionslParagraphs No. Changed Brief Description I Change Authorization 000 All Original Release 4 I.

4 I.

+ I.

F +

Page 4

Controlled Document A

A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table of Contents Page SIGNATURE BLOCK............................................................................................... 2 RECORD OF REVISION .......................................................................................... 4 LIST OF TABLES................................................................................................... 7 LIST OF FIGURES................................................................................................. 9 1.0 PURPOSE................................................................................................. 10 2.0 ANALYTICAL METHODOLOGY........................................................................ 12 2.1 Stress Intensity Factor Solution ......................................................................... 12 2.1.1 Plastic Zone Correction........................................................................ 13 2.2 Fatigue Crack Growth.................................................................................... 18 2.3 Linear Elastic Fracture Mechanics ...................................................................... 19 2.4 Elastic-Plastic Fracture Mechanics ..................................................................... 19 2.4.1 Screening Criteria.............................................................................. 19 2.4.2 Flaw Stability and Crack Driving Force ....................................................... 19 2.5 Primary Stress Analysis.................................................................................. 21 3.0 ASSUMPTIONS .......................................................................................... 22 3.1 Unverified Assumptions .................................................................................. 22 3.2 Justified Assumptions .................................................................................... 22 3.3 Modeling Simplifications ................................................................................. 22 4.0 DESIGN INPUTS......................................................................................... 23 4.1 Geometry.................................................................................................. 23 4.2 Materials................................................................................................... 24 4.2.1 Material Specifications......................................................................... 24 4.2.2 Mechanical Material Properties ............................................................... 24 4.2.3 Fracture Material Properties................................................................... 26 4.3 Transients ................................................................................................. 30 4.4 Finite Element Model..................................................................................... 32 4.4.1 Boundary Conditions .......................................................................... 32 4.4.2 Applied Stresses ............................................................................... 32 5.0 COMPUTER FILES ...................................................................................... 35 5.1 Software................................................................................................... 35 5.2 Computer Files ........................................................................................... 35 6.0 CALCULATIONS ......................................................................................... 39 Page 5

Controlled Document A

ARE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table of Contents (continued)

Page 6.1 Stress Intensity Factors .................................................................................. 39 6.2 Fatigue Crack Growth ............................ ....................................................... 39 6.3 LEFM Evaluation ......................................................................................... 40 6.4 EPFM Evaluations........................................................................................ 43 6.5 Primary Stress Evaluation ............................................................................... 46 6.5.1 Limit Load Finite Element Model.............................................................. 46 6.5.2 Calculation of Flaw Area Removed........................................................... 52

7.0 CONCLUSION

S .......................................................................................... 57

8.0 REFERENCES

............................................................................................ 58 APPENDIX A : UPHILL SIDE FLAW EVALUATIONS....................................................... A-I APPENDIX B : DOWNHILL SIDE FLAW EVALUATIONS ................................................. B-I Page 6

Controlled Document A

AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary List of Tables Page Table 1-1: Safety Factors for Flaw Acceptance ............................................................. 11 Table 4-1: Key Dimensions ................................................................................... 23 Table 4-2: Component Materials.............................................................................. 24 Table 4-3: RVCH Material Properties........................................................................ 24 Table 4-4: J-Groove Weld, and Butter Material Properties................................................. 25 Table 4-5: Cladding Material Properties ..................................................................... 25 Table 4-6: Fracture Material Properties...................................................................... 26 Table 4-7: CVN Test Data..................................................................................... 27 Table 4-8: Transients.......................................................................................... 30 Table 4-9: Emergency and Faulted Transients.............................................................. 31 Table 4-10: Stress Result Files............................................................................... 33 Table 5-1: Computer Files .................................................................................... 35 Table 6-1: Uphill Position 17 LEFM Results................................................................. 41 Table 6-2: Downhill Position 17 LEFM Results.............................................................. 4'2 Table 6-3: Uphill Position 17 EPFM Results................................................................. 44 Table 6-4: Downhill Position 17 EPFM Results ............................................................. 45 Table 6-5: Model Areas Removed by the Cutouts to Represent Postulated Flaws ...................... 54 Table 6-6: Flaw Area Comparison ........................................................................... 56 Table A-I: SIFs for Uphill Side -Welding Residual Stress .................................. A-I Table A-2: SIFs for Uphill Side - Design Condition ....................................................... A-2 Table A-3: SIFs for Uphill Side - [ ] ...................................... A-3 Table A-4: SIFs for Uphill Side - [ ]...................................... A-4 Table A-5: SlFs for Uphill Side - [ ] ......................................... A-5 Table A-6: SIFs for Uphill Side - [ ].............................................. A-6 Table A-7: Fatigue Crack Growth for [ ] (Uphill)................................ A-7 Table A-8: Fatigue Crack Growth for [ ] (Uphill)........................ A-8 Table A-9: Fatigue Crack Growth for [ ] (Uphill)......................... A-9 Table A-10: Fatigue Crack Growth for [ ] (Uphill) ................................. A-10 Table A-Il: Fatigue Crack Growth [ ] (Uphill) ....................... A-Il Table A-12: Fatigue Crack Growth for [] (Uphill) ...................................... A-12 Table A-13: Fatigue Crack Growth for [] (Uphill) ....................................... A-13 Table A-14: Fatigue Crack Growth for [] (Uphill) ........................................ A-14 Table A-IS: Fatigue Crack Growth for [] (Uphill) .................................. A-IS Table A-16: Fatigue Crack Growth for [] (Uphill)..................... A-16 Table A-17: Fatigue Crack Growth for [] (Uphill) ............. A-17 Table A-18: Fatigue Crack Growth for [] (Uphill) .................................. A-18 Page 7

Controlled Document A

AREEVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary List of Tables (continued)

Page Table A-19: Fatigue Crack Growth for [ ] (Uphill) ....................... A-19 Table A-20: Fatigue Crack Growth for [ ] (Uphill)................................... A-20 Table A-21: Fatigue Crack Growth for [ 3(Uphill)........................................... A-21 Table A-22: EPFM Evaluation for [ ] (Uphill) ........................................... A-22 Table B-I: SI~s for Downhill Side- Welding Residual Stress ............................................ B-I Table B-2: SIFs for Downhill Side - Design Condition..................................................... B-2 Table B-3: SI~s for Downhill Side - [ ]3................................... B-3 Table B-4: SlFs for Downhill Side - [ ] .................................. B-4 Table B-5: SIFs for Downhill Side - [ 3 ...................................... B-5 Table B-6: SIFs for Downhill Side - [ 3 .......................................... B-6 Table B-7: Fatigue Crack Growth for [ ] (Downhill) ............................ B-7 Table B-8: Fatigue Crack Growth for [ 3(Downhill) ..................... B-8 Table B-9: Fatigue Crack Growth for [ 3(Downhill) ..................... B-9 Tabie B-10: Fatigue Crack Growth for [] (Downhill).............................. B-I0 Table B-Il: Fatigue Crack Growth for [] (Downhill) .................... B-Il Table B-12: Fatigue Crack Growth for [] (Downhill)................................... B-12 Table B-13: Fatigue Crack Growth for [] (Downhill)..................................... B-13 Table B-14: .Fatigue Crack Growth for [] (Downhill)..................................... B-14 Table B-15: Fatigue Crack Growth for [] (Downhill) ............................... B-15 Table B-16: Fatigue Crack Growth for [] (Downhill) .................. B-16 Table B-17: Fatigue Crack Growth for [] (Downhill) .......... B-17 Table B-18: Fatigue Crack Growth for [] (Downhill) ............................... B-18 Table B-19: Fatigue Crack Growth for [] (Downhill).................... B-19 Table B-20: Fatigue Crack Growth for [] (Downhill)................................. B-20 Table B-21: Fatigue Crack Growth for [] (Downhill)........................................ B-21 Table B-22: EPFM Evaluation for [ 3 (Downhill)........................................ B-22 Page 8

Controlled Document A

AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary List of Figures Page Finite Element Model Isometric View........................................................... 14 Figure 2-I:

Figure 2-2: Uphill Crack Fronts............................................................................... 15 Figure 2-3: Downhill Crack Fronts ........................................................................... 16 Figure 2-4: Initial Flaw Sizes.................................................................................. 17 Figure 4-1: J-R Curves as a Function of Temperature ..................................................... 29 Figure 4-2: Weld Residual Stress Mapped to Downhill Crack Front I .................................... 34 Figure 6-I: Limit Load Model Penetration Layout........................................................... 47 Figure 6-2: Limit Load Model Geometry..................................................................... 48 Figure 6-3: Limit Load Model Finite Element Mesh......................................................... 49 Figure 6-4: Equivalent Stresses at the Limit Pressure...................................................... 50 Figure 6-5: Finite Element Mesh for Limit Load Test Case................................................. 51 Figure 6-6: Limit Load Test Case Equivalent Stress at Limit Pressure.................................... 52 Figure 6-7: Area Calculation Diagram........................................................................ 53 Figure 6-8: Outermost Penetration Crack Face Areas...................................................... 55 Figure 6-9: Crack Growth Area Calculation ................................................................. 56 Figure A-I:

J-T Diagram for [ ] (Uphill) ................................................. A-23 Figure B-I: J-T Diagram for [ ] (Downhill).............................................. B-23 Page 9

Controlled Document A

AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 1.0 PURPOSE Due to concerns that Control Rod Drive Mechanism (CRDM), core exit thermocouple (CETC), and reactor vessel level indication system (RVLIS) nozzle penetration degradation may have occurred in the RVCHs at Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, Exelon Generation Company, LLC (Owner) contracted ARE VA to create a modification to repair these nozzles as a contingency. In the event that a repair is necessary, an ID temper bead weld repair procedure has been developed wherein the lower portion of the nozzle is removed by a boring procedure and the remaining portion is welded to the low alloy steel reactor vessel head above the original Alloy 82/182 J-groove attachment weld. Per Reference [1], fracture mechanics analysis must be performed to justify, the worst-case flaw(s) remaining in the original nozzle-to-RVCH- weld (as-left J-groove weld) at the worst-case location(s). Since a potential flaw in the J-groove weld cannot be sized by currently available non-destructive examination techniques, it is considered that the worst-case as-left condition of the remaining J-groove weld includes degraded or cracked weld material extending through the entire J-groove weld and Alloy 82/182 butter material (due to PWSCC). It is further postulated that this flaw could propagate into the low alloy steel head by fatigue.

The purpose of this calculation is to perform a fracture mechanics analysis of the worst-case flaws in the as-left J-groove weld at the worst-case penetration location. This analysis considers the worst-case nozzle location and utilizes material properties which bound the properties of all four units.

Per Reference [1] the applicable code is ASME Section XI, 2001 Edition with Addenda through 2003 (Reference

[2]). If the service life of the component is shown to be limited, an alternate approach of using ASME Section XI Code Case N-749 (Reference [3]) as modified by the Nuclear Regulatory Commission (see attachment to Reference [4]), will be considered in the evaluation. Acceptance of each postulated flaw is determined based on available fracture toughness or ductile tearing resistance using the safety factors outlined in Table 1-1.

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Controlled Document A

AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 1-1: Safety Factors for Flaw Acceptance LEFM*

Operating Condition Evaluation Method Fracture Toughness / Ki Normal/Upset Kia fracture toughness */10 = 3.16 Emergency/Faulted Kic fracture toughness */2 = 1.41 EPFM Based on Limited Ductile Flaw Extension **

Operating Condition Evaluation Method Primary Secondary Normal/Upset Jo.1 limited flaw extension 2.0 1.0 Emergency/Faulted Jo.1 limited flaw extension 1.5 1.0 EPFM Based on Limited Ductile Flaw Extension and Stability***

Operating Condition Evaluation Method Primary Secondary Normal/Upset J/T based flaw stability 2.14 1.0 Normal/Upset Jo.1 limited flaw extension 1.5 1.0 Emergency/Faulted J/T based flaw stability 1.2 1.0 Emergency/Faulted Jo.1 limited flaw extension 1.25 1.0

• LEFM safety factors are from IWB-3612 of ASME Section XI (Reference [2]).

• • EPFM safety factors based on Section 3.1 of Code Case N-749 (Reference [3]).

• • *EPFM safety factors based on Section 3.2 of Code Case N-749 (Reference [3 ]).

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Controlled Document A

A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 2.0 ANALYTICAL METHODOLOGY The basic analytical methodology is outlined below. Details are provided in the following subsections.

1. Postulate radial-axial flaws in the J-groove weld and butter of the worst case nozzle location. Past experience has shown that the nozzle with the largest hillside angle is the worst case location, which for the current configuration is the CETC nozzle. The radial-axial flaws are postulated since the hoop stresses are dominant.

2. Develop explicit three dimensional finite element crack models of the postulated flaws on the uphill and downhill side in order to calculate the stress intensity factors (SIFs). In order to determine SIFs at varying flaw sizes two uphill crack models and two downhill. crack models will be generated with increasing flaw sizes.

3. Develop a mapping procedure to transfer stresses from an uncracked finite element stress model to the crack face of each crack model, enabling stress intensity factors to be calculated for arbitrary stress distributions over the crack face utilizing the principle of superposition. This strategy makes it possible to obtain pressure and thermal stresses from independent thermal/structural analyses and transfer these stresses to the crack model to support flaw evaluation. Mapping is used for the present assignment to apply residual stresses from weld residual stress analysis and operating stresses from Section III fatigue analysis to the three-dimensional crack models discussed above.

4. Obtain stress intensity factors for each loading condition at varying positions along the crack front by using the ANSYS KCALC command.

5. Calculate fatigue crack growth for cyclic loading conditions using operational stresses from pressure and thermal loads and crack growth rates from Article A-4300 of Section XI for ferritic material in a primary water environment. Residual stresses are included in the fatigue crack growth calculations as a mean stress, which affects the fatigue crack growth rates through the R ratio (Kmj/Kmax).

6. Utilize the screening criteria of ASME Code Case N-749 (Reference [3]) as modified by the N-RC (Reference [4]) to determine the appropriate method of analysis (LEFM or EPFM). For LEFM flaw evaluations, compare the stress intensity factors to the available fracture toughness, with appropriate safety factors. When the material is more ductile and EPFM is the appropriate analysis method, evaluate in accordance with ASME Code Case N-749 (Reference [3]). A limit load analysis is performed to demonstrate that Items 3.1(c) or 3.2(a)(3) of Reference [3] are satisfied. Items 3.1(c) or 3.2(a)(3) requires that the primary stress limit of NB-3000 are satisfied, considering a local reduction of the pressure boundary area equal to the area of the flawed material.

2.1 Stress Intensity Factor Solution The SIF solutions for the postulated flaws evaluated by fracture mechanics analysis are calculated using three-dimensional finite element models with crack tip elements. The model includes the Reactor Vessel Closure Head (RVCH) with existing J-groove weld. The nozzle and IDTB weld are conservatively not included since these materials would provide additional constraint, limiting the crack opening. An isometric view of the overall finite element model developed for this analysis is shown in Figure 2-1.

Radial-axial flaws are postulated and analyzed separately on the uphill and downhill sides of the nozzle and shown in Figure 2-2 and Figure 2-3. For each postulated flaw two finite element models are generated with a flaw size increment of 0.625" in order to capture the variation of SIF with flaw size. For each postulated flaw, STFs are calculated at a total of 17 positions along the crack front starting with position 1 at the RVCH ID and going to position 17 at the nozzle bore as shown in Figure 2-2 and Figure 2-3. Stress intensity factors are Page 12

Controlled Document A

A RE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary calculated using the ANSYS KCALC command (Reference [23]), which deternines the stress intensity factors based on displacements in the vicinity of the crack tip. For "non-classical" flaw shapes with stress intensity factor calculated by the finite element method it is both difficult and unnecessary to prescribe an initial flaw size. In order to track the flaw size during fatigue crack growth any characteristic dimension may be used as the initial flaw size. For this calculation the initial flaw size, a0, is chosen to be the vertical distance along the penetration bore in the finite element model from the inside surface of the cladding to the butter/head interface (see Figure 2-4).

Stress intensity factors at flaw sizes between the modeled flaw sizes are linearly interpolated. If the flaw size is larger than the largest flaw in the fmnite element model, the stress intensity factor is determined using the following scaling rule K1 (a2 ) = K1 (a1 ) **a2 where Ki(al) is a known STF at flaw size a1 and K1(a2) is the desired SIF at flaw size a2. This approach follows from the fundamental expression for the stress intensity factor, K1 = cWq*-, where for a given applied stress and geometry the stress intensity factor scales with the square root of flaw size.

2.1.1 Plastic Zone Correction The Irwin plastic zone correction is used to account for a moderate amount of yielding. For plane strain conditions the correction is (Reference [5], Eq. 2.63) 1 (K,(a)*

Ty= -ir o\ )l where K1(a) is the stress intensity factor at the actual crack size (a), and CTyis the material's yield strength. The effective crack size, ae, is calculated as ae = a +r The stress intensity factor at the effective flaw size is then calculated using the scaling law derived above as Ki(ae) = K1 (a) a*_

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A A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary ANSYS R14.5 Crack Modiel = uhl Figure 2-1" Finite Element Model Isometric View Page 14

Controlled Document A No. 32-9244434-000 AREVADocument Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 2-2: Uphill Crack Fronts Page 15

Controlled Document A

No. 32-9244434-000 Aft EVADocument Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 2-3: Downhill Crack Fronts Page 16

Controlled Document A

A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle Aa-Left i-Groove Analysis - Non Proprietary Figure 2-4: Initial Flaw Sizes Page 17

Controlled Document A

A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 2.2 Fatigue Crack Growth Fatigue crack growth is calculated using the fatigue crack growth rate model from Article A-4300 of Reference

[2] as da

= Co(AKI)y where AK1 is the stress intensity factor range in ksi~in, and da/dN is the crack growth rate in inches/cycle. The crack growth rates for a surface flaw will be utilized since the postulated flaw(s) would result in the low alloy steel head being exposed to the primary water environment.

The detailed equations for calculating the fatigue crack growth rate are presented below.

AxK 1 KMaX - KMtfl R = KMtn/KMax 0*<R*_<0.25, AK < 17.74 n = 5.95 S= 1.0 Co = 1.02 x 10-' 2 S AK 1 Ž_ 17.74 n =1.95 S = 1.0 C0 1.01 x 10-7S 0.25 < R < 0.65, AK1 < 17.74[(3.75R + 0.06)/(26.9R - 5.725)]0.25 n = 5.95 S = 26.9R - 5.72 5 C0 = 1.02 x 10-2 S AK1 _>17.74[(3.75R + 0.06)/(26.9R - 5.725)]°'2s n = 1.95 S = 3.75R + 0.06 CO = 1.01 X 10- 7 S 0.65 < B < 1.00, AK1 < 12.04 n = 5.95 S = 11.76 Co = 1.02 x 10-12S AK1 > 12.04 n = 1.95 S =2.5 CO = 1.01 x iO-7S Page 18

Controlled Document A

AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 2.3 Linear Elastic Fracture Mechanics After fatigue crack growth is calculated the flaw is evaluated using Linear Elastic Fracture Mechanics (LEFM).

Article IWB-36 12 of Section XI (Reference [2]) requires that the applied stress intensity factor be less than the available fracture toughness at the crack tip temperature, with appropriate safety factor, as outlined below.

Normal/Upset Conditions: K1 '<KIa/'ITO Emergency/Faulted Conditions: K1 < K1 c/W-In the above Kia is the fracture toughness based on crack arrest and K1c is the fracture toughness based on crack initiation. In the evaluation of the above limits, a plastic zone correction is incorporated using the methodology described in Section 2.1.1 2.4 Elastic-Plastic Fracture Mechanics Elastic-plastic fracture mechanics (EPFM) will be used as an alternative acceptance criteria when the flaw related failure mechanism is unstable ductile tearing. LEFM would be used to assess the potential for non-ductile failure, while limit analysis would be used to check for plastic collapse.

2.4.1 Screening Criteria ASME Code Case N-749 states that EPFM acceptance criteria are applicable to ferritic steel components on the upper shelf of the Charpy energy curve when the metal temperature exceeds the upper shelf transition temperature, To. The NRC has proposed a modification to the Code Case definition of To, which is given below (see Reference [4]).

Tc=170.4°F + 0.814 x RTNDT When the metal temperature exceeds Tc, EPFM analysis is applicable, otherwise LEFM analysis is applicable.

2.4.2 Flaw Stability and Crack Driving Force Elastic-plastic fracture mechanics analysis will be performed based on ASME Code Case N-749 (Reference [3])

to evaluate crack driving force and flaw stability (if applicable). Two possible sets of acceptance criteria for EPFM are defined in Code Case N-749:

• Section 3.1 Acceptance Criteria Based Solely on Limited Ductile Crack Extension, or

• Section 3.2 Acceptance Criteria Based on Limited Ductile Crack Extension and Stability.

Section 3.1 states that the flaw is acceptable if the crack driving force, as measured by the applied J-integral (Japp) with appropriate safety factors applied to the loads, is less than the than the J-integral of the material (Jmat) at a ductile crack extension of 0.1 inch (J0.1). If the criteria of Section 3.1 are not met, the flaw may still be acceptable if the criteria of Section 3.2 are met. Section 3.2 allows lower safety factors for the crack driving force check, and additionally requires that flaw stability be evaluated with appropriate safety factors. The flaw stability analysis will be performed using a J-integral/tearing modulus (J-T) diagram to evaluate flaw stability under ductile tearing, where J is either the applied (Japp) or the material (Jrnat) J-integral, and T is the tearing modulus, defined as (E/ay')

(8J/Oa). Flaw stability and crack driving force assessments will utilize the safety factors from Code Case N-749 as outlined in Table 1-1.

The general methodology for performing an EPFM analyses is outlined below.

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Controlled Document A

A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Let E"= E/(1-v7)

Final flaw depth = a Total applied/K, Kiapp K1 due to pressure (primary) =Ki K1 due to residual plus thermal (secondary) =Kis =Kiapp -Kp Safety factor on primary loads = SFp Safety factor on secondary loads = SF5 Total applied K1 with safety factors, 1("= SFp*K!6, + SF*/KIN For small scale yielding at the crack tip, a plastic zone correction (see Section 2.1.1) is used to calculate an effective flaw depth based on ae =a+- 6-which is used to update the total applied stress intensity factor based on K= KI*a The applied I-integral is then calculated using the relationship The applied I-integral is checked against 10.1, demonstrating that the crack driving force falls below the J-R curve at a crack extension of 0.1 inch.

For flaw stability analysis, the final parameter needed to construct the J-T diagram is the tearing modulus. The applied tearing modulus, Tapp, is calculated by numerical differentiation for small increments of crack size (cia) about the crack size (a), according to Tapp = kE (]'app(a + d)-apda -a)2 "

The material J-T curve is determined as described in Section 4.2. Constructing the J-T diagram as shown below, Page 20

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary T

flaw stability is demonstrated at an applied J-integral when the applied tearing modulus is less than the material tearing modulus. Alternately, the applied J-integral is less than the J-integral at the point of instability.

2.5 Primary Stress Analysis Items 3.1 (c) and 3.2(a)(3) of Reference [3] state that the flawed component must meet the primary stress limits of NB-3000, assuming a local area reduction of the pressure retaining membrane that is equal to the area of the flaw.

To evaluate the requirement, article NB-3228.l of Section III of the ASMVE Code [24] is utilized. NB-3228.1 states that the limits on General Membrane Stress Intensity (NB-322 1.1), Local Membrane Stress Intensity (NB-3221.2), and Primary Membrane Plus Primary Bending Stress Intensity (NB-322 1.3) need not be satisfied at a specific location if it can be shown by limit analysis that the specified loadings do not exceed two-thirds of the lower bound collapse load. The yield strength to be used in these calculations is 1.5 Sm. Per NB-3 112.1(a) the Design Pressure shall be used in showing compliance with this limit.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 3,0 ASSUMPTIONS 3,1 Unverified Assumptions No unverified assumptions are used in this calculation.

3.2 Justified Assumptions The following justified assumptions are used in this calculation:

1. For fatigue crack growth calculations cycles are assumed to accumulate at a linear rate, i.e., in each year the number of cycles utilized is the total number of design cycles divided by the plant design life. This assumption is reasonable since experience shows that linear rates generally envelope the accumulation rates observed for transients based on plant operating experience (see Reference [6], TODI-BYR-15-008 cycle counts).

2. A 20 year license extension for each unit is assumed. Based on this and review of current license expiration dates for each unit fatigue crack growth for 33 years is considered.

3. For the limit load analysis (Section 6.5.1), an eighth symmetric model is utilized. The actual symmetry of the CRDM nozzle layout is quarter rotational symmetry. The eighth of the head modeled results in one additional CRDM penetration in each quadrant, which conservatively removes more material (i.e., there is less metal available to carry the applied loadings) and has negligible effect on the applicability of the symmetry boundary condition due to the size of the penetration compared to the size of the head.

3.3 Modeling Simplifications The following modeling simplifications are used in this calculation:

1. The geometry of the J-groove weld and butter is simplified to allow for a high quality mesh in this area and insertion of the crack tip elements needed to calculate stress intensity factors. Simplifications include the "kink" in the crack fronts rather than a smooth radius and neglecting the small fillet weld. These simplifications are typical of these types of analysis and do not impact the results.

2. For the limit load analysis (Section 6.5.1), the material removed to represent the J-groove weld, butter and crack growth has a simplified geometry to facilitate modeling. This simplification has no impact since acceptable area is removed.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 4.0 DESIGN INPUTS 4.1 Geometry The existing geometry of the RVCH and J-groove weld(s) for each unit are show in References [7], [8], [9], [10],

[11], [12], [13], and [14]. The proposed repair configuration is provided in References [15] and [16]. Key dimensions are listed in Table 4-1.

Table 4-1: Key Dimensions Description Value Reference/Comments Head Inside Radius to Cladding [ ] [16]

Head Thickness [ ] [16]

Cladding Thickness [ ] [16]

Bore Diameter [ ] [16]

Horizontal Radius to Outermost Penetration [ ] [16]

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AR EVA Document No, 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 4.2 Materials 4.2.1 Material Specifications The material designations of each component are listed in Table 4-2.

Table 4-2: Component Materials Component Material Reference/Comments RVCH SA-533 Grade B Class 1 Reference [1]

Cladding Austenitic Stainless Steel (304) Reference [6], Equip.

Spec 676413 Existing J-Groove Weld/Buttering Alloy 182 (ENiCrFe-3) or Alloy 82 (ERNiCr-3) Reference [1]

4.2.2 Mechanical Material Properties The material properties are taken from the original construction code, Reference [17]. The material properties for each component are provided in Table 4-3, Table 4-4, and Table 4-5. The SB-167 Alloy 600 properties are also used for the Alloy 82/182 weld filler metals.

Table 4-3: RVCH Material Properties SA-533 Grade B Class 1 (C-Mn-Mo 0.4-0.7Ni)

Temperature (*F) a (1/*F) E (psi) v (-) av (ksi) u. (ksi) 70 6.07E-06 2.99E+07 0.3 50 80 100 6.13E-06 2.98E+07 0.3 50 80 200 6.38E-06 2.95E+07 0.3 47.1 80 300 6.60E-06 2.90E+07 0.3 45.2 80 400 6.82E-06 2.86E+07 0.3 44.5 80 500 7.02E-06 2.80E+07 0.3 43.2 80 600 7.23E-06 2.74E+07 0.3 42 80 650 7.33E-06 2.70E+07 0.3 41.4 80 700 7.44E-06 2.66E+07 0.3 40.6 80 Reference [17] Location Table I-5.0, Coeff. B Table 1-6.0 Typical Table I-2.1 Table 1-1.1 Page 24

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 4-4: J-Groove Weld, and Butter Material Properties SB-167 Alloy 600 (Ni-Fe-Cr) 0 Temperature ( F) a (1/°F) E (psi) v (-) oy (ksi) au (ksi) 70 7.13E-06 3.17E+07 0.3 35 80 100 7.20E-06 3.15E+07 0.3 35 80 200 7.40E-06 3.09E+07 0.3 32.7 80 300 7.56E-06 3.05E+07 0.3 31 80 400 7.70E-06 3.00E+07 0.3 29.8 80 500 7.80E-06 2.96E+07 0.3 28.8 80 600 7.90E-06 2.92E+07 0.3 27.9 80 650 7.95E-06 2.89E+07 0.3 27.4 80 700 8.00E-06 2.86E+07 0.3 27 80 Reference [17] Location Tablel1-5.0, Coeff. B Table 1-6.0 Typical Tablel1-2.2 Tablel1-1.2 Table 4-5: Cladding Material Properties Austenitic Stainless Steel (304)

Temperature (0F) a (1/°F) E (psi) v (-)

70 9.11E-06 2.83E+07 0.3 100 9.16E-06 2.82E+07 0.3 200 9.34E-06 2.77E+07 0.3 300 9.47E-06 2.71E+07 0.3 400 9.59E-06 2.66E+07 0.3 500 9.70E-06 2.61E+07 0.3 600 9.82E-06 2.54E+07 0.3 650 9.87E-06 2.51E+07 0.3 700 9.93E-06 2.48E+07 0.3 Reference [17] Location Tablel1-5.0, Coeff. B Tablel1-6.0 Typical Page 25

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 4.2.3 Fracture Material Properties Table 4-6 provides the reference temperature for nil-ductility (RTNqDT), and the sulfur content for the closure head center disc for each of the four units (Reference [18]). The analysis performed in this calculation uses the bounding values of all units, which is an RTNDT of [ .]

Table 4-6: Fracture Material Properties Plant Unit Heat No. RTNDT (°F) Sulfur (wt %)

Byron 1 C3486-1 [ ] [ ]

Byron 2 C4375-2 [ ] [ ]

Braidwood 1 D1398-1 [ ] [ ]

Braidwood 2 B9754-1 [ ] [ ]

Reference [ 18] provides an estimate of the Charpy V-notch upper-shelf energy (USE) which is based on the average energy from CV~N tests at RTNDT-+60 0F. Review of the Charpy data provided in the CMTRs attached to Reference [18] indicates that this is a very conservative estimate of USE, as the percent shear fractures range from 50%-60% at this level. Per Reference [20], USE is defined by ASTM El185 (Reference [19]), which provides the following definition of the USE:

Charpy upper-shelfenergy level--the average energy value for all Charpy specimen tests (preferably three or more) whose test temperature is at or above the Charpy upper-shelf onset; specimens tested at temperatures greater than 83°C (150°F) above the Charpy upper-shelf onset shall not be included, unless no data are available between the onset temperature and onset +83 0 C (+1 500 F).

Charpy upp er-shelfonset--the test temperature above which the fr~acture appearance of all Charpy specimens tested is at or above 95% shear.

The CVN test data from the CMThs is provided in Table 4-7. From Table 4-7, a lower bound USE of

[] is selected based on the Braidwood 1 data at [ J where the percent shear fracture is

[ ] Note that the use of data at [ ] shear fracture is still conservative relative to the ASTM definition of 95% shear fracture.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 4-7: CVN Test Data p

Enerev Ift-lbsl Percent Shear Fracture Plant Temperature (F) Test 1 Test 2 Test 3 Average Test1IITest 2 Test 3 Byron 1 212 Byron 1 100 Byron 1. 70 Byron 1 50 Byron 1 40 Byron 1 10 Byron 1 -150 Byron 2 212 Byron 2 100 Byron 2 80 Byron 2 60 Byron 2 20 Byron 2 -50 Byron 2 -100 Braiwood1 21 Braidwood 1 212 Braidwood 1 30 Braidwood 1 30 Braidwood 1 -0 Braidwood 1 -60 Braidwood 1 -100 Braidwood 2 2120 Braidwood 2 702 Braidwood 2 60 Braidwood 2 60 Braidwood 2 -0 Braidwood 2 -20 Braidwood 2 -60 h-I Page 27

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary From Article A-4200 of Reference [2], the lower bound fracture toughness for crack arrest, KIa, is calculated as Kia =26.8 + 12.445exp[0.0145(T - RTNDr)]

where T is the crack tip temperature, Kia is in units of ksi*in, and T and RTNDT are in units of °F. In the present calculations, Kia is limited to a maximum value of 200 ksi*Iin (upper-shelf fracture toughness). The crack arrest Kia upper shelf toughness of 200 ksilin is achieved at T-RTNDT > 182 °F.

A higher measure of fracture toughness is provided by the K~c fracture toughness for crack initiation, approximated in Article A-4200 of Section XI (Reference [2]) by Kc= 33.2 + 20.734exp[0.02(T - RTNDT)]

The crack initiation Kic upper shelf toughness of 200 ksi'*in is achieved at T-RTNDT > 105 °F.

The J-integral resistance (J-R) curve, needed for the EPFM method of analysis, is obtained from the following correlation for reactor pressure vessel plate with less than 0.0 18 weight percent sulfur (Reference [20], Section 3.3.1)

]mat = MF{Ci(Aa)c2 exp(C 3 (Aa)c4) }

where MF is a margin factor, and Aa is the crack extension. C, are constants which depend on the crack tip temperature and the Charpy V-notch upper-shelf energy as defined below C1 exp (-2.44 + 1.13 ln(CVN) - 0.00277T)

C2 = 0.077 + 0.116 In C1 C3 = -0.0812 - 0.0092 InC1 C4 = -0.409 where CVN is the Charpy V-notch upper-shelf energy in ft-lbs, and T is the crack tip temperature in °F. In this analysis the margin factor, MF, is taken as 0.749 for all cases including faulted where it may be taken as one. The resulting material J-R curve is plotted for several temperatures in Figure 4-1.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 4-1: J-R Curves as a Function of Temperature The material tearing modulus is calculated using the following equation Tmat -(E*)

0 mata where E is the Elastic Modulus, of is the flow stress defined as 0.5(oIy + ( 11), an~d the derivative of the J-R curve is

=~aMFtCiC2 (Aa)C2- 1 + CiC3 C4 (Aa)C2+C4- 1 }exp(C3 (Aa)c4) da Page 29

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 4.3 Transients Fatigue crack growth will be calculated for the Normal and Upset transients listed in Table 4-8, based on Table 4-6 of the Section IlI analysis (Reference [22]). Per Reference [6] (TODI-BYR- 15-008) the design cycles specified are applicable for a [ ] life.

Table 4-8: Transients Transient Abbreviation Service Level Cycles Cycles/Year Normal Normal Normal Normal Normal Upset Upset Upset Upset Upset Upset Upset Upset Test Test

.11 Additionally, the Emergency and Faulted transient pressure temperature curves provided in Reference [6] (TODI BYR- 15-009 & TODI BYR- 15-012) were reviewed and the critical transients were selected for analysis based on the discussion below in Table 4-9. Emergency and Faulted transients have a small number of cycles (5 or less) and are therefore not considered for fatigue.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 4-9: Emergency and Faulted Transients Page 31

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 4.4 Finite Element Model The finite element model utilized is a three-dimensional half symmetry model. The model is meshed using ANSYS element types SOLID 186 and SOLID 187. The crack tip elements are SOLID 186 elements collapsed into wedges with the appropriate mid-side nodes moved to the quarter points to simulate the singularity at the crack tip. A base geometry and mesh are generated in the input file "base model.inp", and the explicit crack models are then created by replacing the appropriate brick elements with crack tip elements using the files "gen crack_models.inp" and "CrackFanMesh2.mac".

4.4.1 Boundary Conditions The displacements are constrained normal to the face of the symmetry plane and the additional model cutting planes. The displacements of the nodes on the crack face are not constrained.

4.4.2 Applied Stresses Applied stresses are due to residual stresses and operating stresses. Residual stresses are obtained from the 3-D weld residual stress calculation documented in Reference [21]. Stresses are mapped to the crack face from the residual stress model to the crack finite element model through arrays of nodal locations and hoop stresses documented in Appendix B of Reference [21 ]. Figure 4-2 shows an example of the weld residual stresses mapped onto downhill crack face 1 side by side with contour plot of the stress from Reference [21]. Operating stresses are taken from the corresponding ASME Section III calculation (Reference [22]) and mapped to the crack face using the same methodology as the residual stresses. The operating pressure is also applied to the crack face to account for the additional loading.

The files used for stress results from References [21] and [22] are listed in Table 4-10.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 4-10: Stress Result Files Load IStress File Page 33

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 4-2: Weld Residual Stress Mapped to Downhill Crack Front I Page 34

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ARE EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 5.0 COMPUTER FILES 5.1 Software ANSYS Version 14.5.7 (Reference [23]) was used in this analysis. Error notices were reviewed and none are applicable to the features utilized in this analysis, therefore, the use of this version is acceptable. All modeling and analyses were performed on the following computer:

• DELL Precision M6600, Intel(R) Core(TM) i7-2640M CPU @ 2.80GHz, 8GB of RAM

• Operating System: Windows 7, Service Pack 1, 64 Bit

• Name of person running tests: Tom Riordan

• Date of Tests Before Runs: February 23, 2015

• Date of Tests After Runs: May 1, 2015 The test problem vm143 was run before and after the analysis and the results were found to be acceptable as documented in output files "vm143.out" and "vm143.vrt" (see Table 5-1).

5.2 Computer Files The computer files are listed in Table 5-I. Files are stored in ColdStor at the following path:

\cold\General-Access\32\32-9000000\32-92367 13-000\official Table 5 Computer Files CRC Checksum File Size (bytes) Modified Date Time File Name 21263 1578 Mar 9 2015 20:49:48 Design dhl.Kt 60449 1578 Mar 9 2015 22:18:41 Design dh2.KI 43257 1578 Mar 9 2015 17:40:33 Design uhl.KI 07900 1578 Mar 9 2015 19:10:35 Design uh2.KI 21104 3300 Feb 10 2015 12:36:22 Get_SIF.mac 03319 3386 Feb 23 2015 19:08:04 SIFDriver.mac 14846 326 Feb 23 2015 10:06:44 SIF~calc.inp 03910 82149439 Mar 10 2015 0:04:51 SIF calc.out 43416 6838 Mar 9 2015 20:52:58 TrCDst dhl.KI 31139 6838 Mar 9 2015 22:22:30 TrCD st dh2.KI 24024 6838 Mar 9 2015 17:43:46 TrCDst uhl.KI 33054 6838 Mar 9 2015 19:14:07 TrCD st uh2.KI 26871 9994 Mar 9 2015 20:57:50 Tr_CRDst dhl.KI 49184 9994 Mar 9 2015 22:28:22 TrCRDst dh2.KI 23505 9994 Mar 9 2015 17:48:41 TrCRD st uhl.KI 60584 9994 Mar 9 2015 19:19:32 TrCRD st_uh2.KI 18031 8416 Mar 9 2015 21:01:51 Tr_CREJ_st_dhl.KI 08844 8416 Mar 9 2015 22:33:12 TrCREJ st dh2.KI Page 35

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary CRC Checksum File Size (bytes) Modified Date TimeNamFile Name 52638 8416 Mar 9 2015 17:52:46 Tr_CREJst uhl.KI 40552 8416 Mar 9 2015 19:24:00 Tr_CREJ_st_uh2.KI 01489 7890 Mar 9 2015 21:05:35 Tr_FWC_st_dhl.KI 05454 7890 Mar 9 2015 22:37:41 TrFWC st dh2.KI 5973 780 Mr 9 01517:6:3 TrWC~t~ul.K 41752 7890 Mar 9 2015 19:28:39 TrFWC_st_uh2.KI 39983 5786 Mar 9 2015 21:08:10 TrHUst dhl.KI 44194 5786 Mar 9 2015 22:40:46 TrHU st dh2.KI 00116 5786 Mar 9 2015 17:59:10 TrHUst uhl.KI 24397 5786 Mar 9 2015 19:31:30 TrHU st uh2.KI 22332 1578 Mar 9 2015 21:08:28 Tr_HYDR_st_dhl.KI 58287 1578 Mar 9 2015 22:41:07 Tr_HYDR_st_dh2.KI 33547 1578 Mar 9 2015 17:59:28 Tr_HYDR_st_uhl.KI 34672 1578 Mar 9 2015 19:31:50 TrHYDR st uh2.KI 16128 7890 Mar 9 2015 21:12:12 TrIDPR st dhl.KI 58366 7890 Mar 9 2015 22:45:34 Tr_IDPR_st_dh2.KI 37100 7890 Mar 9 2015 18:03:14 TrIDPR st uhl.KI 05728 7890 Mar 9 2015 19:35:58 Tr IDPR st uh2.KI 12377 14202 Mar 9 2015 21:19:22 Tr_15Ist dhl.KI 60741 14202 Mar 9 2015 22:54:12 TrISIst dh2.KI 50307 14202 Mar 9 2015 18:10:30 TrISIst uhl.KI 45145 14202 Mar 9 2015 19:43:57 Tr_15Ist uh2.KI 16826 7890 Mar 9 2015 21:23:06 TrISTst dhl.KI 204S5 7890 Mar 9 2015 22:58:40 TrISTst dh2.KI 47038 7890 Mar 9 2015 18:14:18 TrIST st uhl.KI 04858 7890 Mar 9 2015 19:48:05 Tr_1STst uh2.KI 53576 2630 Mar 9 2015 21:23:58 Tr_LEAK st dhl.KI 63228 2630 Mar 9 2015 22:59:43 TrLEAKst dh2.KI 18199 2630 Mar 9 2015 18:15:10 TrLEAK st uhl.KI 13851 2630 Mar 9 2015 19:49:03 Tr LEAK st uh2.KI 50913 13150 Mar 9 2015 21:30:34 TrLOF_st dhl.KI 01496 13150 Mar 9 2015 23:07:38 Tr_LOF_st_dh2.KI 11614 13150 Mar 9 2015 18:21:52 Tr_LOFst uhl.KI 48527 13150 Mar 9 2015 19:56:23 Tr_LOF_st_uh2.KI 35510 8942 Mar 9 2015 21:34:53 Tr_LOP st dhl.KI 15662 8942 Mar 9 2015 23:12:49 Tr_LOPst dh2.KI 13722 8942 Mar 9 2015 18:26:14 TrLOPst uhl.KI 56332 8942 Mar 9 2015 20:01:10 Tr_LOPst uh2.KI 54380 9994 Mar 9 2015 21:39:45 TrLSB st dhl.KI 37299 9994 Mar 9 2015 23:18:39 Tr_LSB_st_dh2.KI 22926 9994 Mar 9 2015 18:31:11 TrLSBst uhl.KI 07182 9994 Mar 9 2015 20:06:37 TrL5Bst uh2.KI Page 36

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ARE EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary CRC Checksum File Size (bytes) Modified Date TimeNam File Name 31946 10520 Mar 9 2015 21:44:56 Tr_LSLDst dhl.KI 37662 10520 Mar 9 2015 23:24:52 Tr_LSLD st dh2.KI 28612 10520 Mar 9 2015 18:36:27 Tr_LSLD st uhl.KI 53332 10520 Mar 9 2015 20:12:24 Tr_LSLD_st_uh2.KI 46341 9468 Mar 9 2015 21:49:30 TrPL st dhl.KI 16512 9468 Mar 9 2015 23:30:22 Tr PL st dh2.KI 43281 9468 Mar 9 2015 18:41:07 TrPLst uhl.KI 26618 9468 Mar 9 2015 20:17:29 TrPLst uh2.KI 41536 9994 Mar 9 2015 21:54:23 TrPUst dhl.KI 30086 9994 Mar 9 2015 23:36:14 TrPU st dh2.KI 25843 9994 Mar 9 2015 18:46:03 TrPUst uhl.KI 30445 9994 Mar 9 2015 20:22:56 TrPU st uh2.KI 57260 7364 Mar 9 2015 21:57:49 Tr_RCPB st dhl.KI 45070 7364 Mar 9 2015 23:40:20 TrRCPB st dh2.KI 15759 7364 Mar 9 2015 18:49:33 TrRCPB st uhi.KI 19950 7364 Mar 9 2015 20:26:46 Tr_RCPBst uh2.KI 39199 10520 Mar 9 2015 22:03:00 TrRTst dhl.KI 02804 10520 Mar 9 2015 23:46:34 Tr RT st dh2.KI 42095 10520 Mar 9 2015 18:54:48 TrRT st uhl.KI 17981 10520 Mar 9 2015 20:32:30 TrRTst uh2.KI 00064 8416 Mar 9 2015 22:07:02 TrSLDst dhl.KI 31844 8416 Mar 9 2015 23:51:23 TrSLDst dh2.KI 42805 8416 Mar 9 2015 18:58:53 TrSLD st uhl.KI 26036 8416 Mar 9 2015 20:36:59 Tr SLD st uh2.KI 05984 8942 Mar 9 2015 22:11:21 TrSLIst dhl.KI 11211 8942 Mar 9 2015 23:56:34 TrSLIst dh2.KI 36053 8942 Mar 9 2015 19:03:15 TrSLIst uhl.KI 15136 8942 Mar 9 2015 20:41:48 TrSLIst uh2.KI 29896 7890 Mar 9 2015 22:15:09 TrSSB st dhl.KI 43498 7890 Mar 10 2015 0:01:02 Tr SSB st dh2.KI 11972 7890 Mar 9 2015 19:07:02 TrSSBst uhl.KI 13532 7890 Mar 9 2015 20:45:59 TrSSB_st_uh2.KI 32334 6838 Mar 9 2015 22:18:19 TrTRT st dhl.KI 64867 6838 Mar 10 2015 0:04:50 TrTRT st dh2.KI 16300 6838 Mar _9 2015 19:10:15 TrTRT st uhl.KI 01608 6838 Mar 9 2015 20:49:30 TrTRTst uh2.KI 12170 845 Feb 10 2015 12:36:04 calc_k.mac

./KIWRS:

21104 3300 Feb 10 2015 12:36:22 Get_SIF.mac 53662 2385 Mar 26 2015 17:38:40 SIF_Driver_WRS.mac 58341 342 Mar 26 2015 17:36:31 SlF~calc.inp Page 37

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary CRC Checksum File Size (bytes) Modified Date Time File Name 40929 342533 Mar 26 2015 17:40:17 SIF calc.out 21270 864600 Mar 26 2015 16:42:36 WRS_JG.out 14702 1578 Mar 26 2015 17:39:55 WRS dhl.KI 19074 1578 Mar 26 2015 17:40:16 WRS_dh2.KI 45110 1578 Mar 26 2015 17:39:17 WRS_uhl.KI 02636 1578 Mar 26 2015 17:39:37 WRS_uh2.KI 12170 845 Feb 10 2015 12:36:04 calc_k.mac

./LimitLoad:

43418 14478341 May 1 2015 7:52:06 BBHead_EighthSymm geom.inp 08136 2497 May 1 2015 7:53:31 BB_Head_LL.inp 14343 388270 May 1 2015 8:28:27 BB_HeadLL.out 24444 1183 May 1 2015 9:03:30 SphereLL~inp 34694 111381 May 1 2015 9:22:43 Sphere_..LL.out 59712 12824244 May 1 2015 8:54:56 Sphere geom.inp 52686 10355 Apr 9 2015 16:38:20 materials_LL.inp

.1MoadelI:

46075 9664611 Feb 9 2015 11:22:02 Base_Model.inp 08317 6653 Dec 16 2013 9:41:18 CrackFanMesh2.mac 50705 8654 Feb 10 2015 12:03:02 gen crack models.inp 55233 669743 Feb 23 2015 16:03:11 gen crack models.out 31314 9917 Dec 11 2013 17:45:05 materials.inp

./Spreadsheets:

21706 144488 May 1 2015 10:02:13 BB_Weld_Removed_Area.xlsx 30682 558077 Apr 8 2015 11:39:32 EPFM-RG1161_dh.xlsm 38937 557641 Apr 8 2015 11:22:11 EPFM-RG1161_uh.xlsm 32149 397032 Apr 8 2015 11:40:41 LEFM_FCG_dh.xlsm 04536 376452 Apr 8 2015 11:22:16 LEFM_FCG_uh.xlsm

./Verification/Post:

34097 14718 Mar 16 2013 18:00:53 vm143.dat 48177 100295 May 1 2015 10:17:48 vm143.out 39033 766 May 1 2015 10:17:48 vm143.vrt

./Verification/Pre:

34097 14718 Mar 16 2013 18:00:53 vm143.dat 41169 100534 Feb 23 2015 9:23:05 vm143.out 39033 766 Feb 23 2015 9:23:05 vm 143.vrt Page 38

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 6.0 CALCULATIONS 6.1 Stress Intensity Factors SI~s are calculated for each postulated crack front using the WRS and Section 1II stress results from the files listed in Table 4-10. The calculations are run by the ANSYS input file "SIP calc.inp". The ANSYS macros "SIPDriver.mac" and "SIP_DriverWRS.mac" set the crack face boundary conditions, read in data from the stress models (WIRS or Section III), and set up data arrays. The file "Get_SIF.mac" is used to perform stress mapping, solve the model with mapped stresses and then calculate the SIP s (using "calc~k.mac"). The SIF calculation results are written to the "*.KI" output flies (see Table 5-1), which contain the SIFs for each step of a transient as well as a summary of the minimum and maximum SIP for the transient.

Upon reviewing the results of the uphill stress intensity factor calculations for the Design Condition it was seen that at positions near the bore (e.g., 16 and 17) the stress intensity factor is lower at crack front 2 than crack front 1; this is a result of the fact that stress results from the Section III model include additional constraint from the IDTB weld which is near the uphill crack front 2. In cases where the hillside angle is less steep the TDTB weld may not be as near to the J-groove weld. Therefore, it was decided that for conservatism the uphill crack front 2 results would not be used in calculations; instead, the stress intensity factors at flaw sizes larger than uphill crack front 1 will be conservatively extrapolated using the scaling rule described in Section 2.1.

The simplified geometry of the postulated flaw shapes discussed in simplification I of Section 3.3 results in low SI~s at some locations along the crack front (see tabulated values in Appendix A and Appendix B) such as at the "kink" at position 9 on the uphill side (Figure 2-2), and near the head ID surface at position 1 on the downhill side (Figure 2-3). The low values in these areas result because crack tip opening at these locations is restrained by other portions of the crack front due to the postulated flaw geometry. This has no impact on the results since these are not the controlling locations.

The boundary conditions utilized (Section 4.4.1) release the nodes on the crack face; in cases where there is compressive stress, the crack face may close (i.e., move across the symmetry plane) producing positive SIFs where there should not be. For example, on uphill crack face 1, closure occurs only in one of the steps of the [ ]

transient. This closure results in small positive values ( [ ] at position 17) that are near the minimum.

The positive value predicted during closure would have a minor impact on the fatigue crack growth due to larger delta K, but with a beneficial effect of smaller R ratio. Very localized closure also occurs near the surface in transients such as a [ J transient where there is a rapid increase in the temperature causing a compressive skin stress; in this case, the majority of the crack face remains open, and therefore would only be minimally affected. The overall effect on the analysis due to the small amount of crack face closure observed is minimal.

6.2 Fatigue Crack Growth Utilizing the SIP solutions described in Section 6.1, fatigue crack growth is calculated. The fatigue crack growth rule in Section 2.2 is integrated numerically using, da Aa

• . C(A~~nor Aa ANCo(AK 1)n The impact of the cycle increment (AN) was investigated, and it was found that utilizing the number of cycles per year was a sufficiently small increment to accurately integrate the crack growth. Therefore, crack growth presented in this report has been calculated on a per year basis.

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Based on review of the results, the stress intensity factors at position 17 at the nozzle bore on both the uphill and downhill side are typically largest. Exceptions to this occur in transients with rapid temperature drops which create high thermal stresses near the ID of the RVCH. The subsequent EPFM analyses will apply lower safety factors to these secondary stresses. Therefore, the nozzle bore locations are considered bounding and chosen for detailed evaluation. Fatigue crack growth calculations for position 17 on the uphill side and position 17 on the downhill side are performed in the spreadsheets "LEFM_FCG_uh.xlsm" and "LEFM_FCG_dh.xlsm" (see Table 5-1), and the detailed results are shown in Appendix A and Appendix B, respectively.

6.3 LEFM Evaluation LEFM evaluations are performed for the final flaw size from the fatigue crack growth evaluation. The applied SIF is evaluated accounting for the plastic zone correction described in Section 2.1.1, and its acceptability is evaluated based on the rules outlined in Section 2.3. The results for uphill position 17 and downhill position 17 are shown in Table 6-1 and Table 6-2, respectively.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 6-1: Uphill Position 17 LEFM Results RTemertureL( FF i UprShef ouhnss20i)~

ze ain)

Loadinglawsi

(

Kntia ServIce Level a TemperatureJ-ain

('F)

=

Preasure (psi)

CracGrowth Sy (ksl)

K,, (ksivin)

K,. (kaiVin)

K(a) (kaivin) a,(ln)

K(a.) (in)

Margin K5JK(a~)

Margin K,./K(a~)

Required Margin Acceptable By LgFM?

MeetaTcCriterionforEPFM?

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 6-2: Downhill Position 17 LEFM Results

-i

-i s)i Upe S hef ouhnsk20 Loading 5 Service Level Sine)

Faw Fina Temperature ('F)

(rwtin)

Pressure (psi)

Crack Sy(ksi)

Kk(kaivin)

K,, (Issivin)

K(a) (ksivin) e,(in)

K(a,) (in)

Margin = KJK(a.)

Margin = Kr./K(a,)

Required Margin Acceptable By LEFM?

MeetsTcCriterionforEPFM?

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Review of the results of Table 6-1 and Table 6-2 indicates that with few exceptions the LEFM acceptance criteria are not met; however, in all cases shown except the Hydrostatic test and the [ ] the temperature exceeds [ ] and may therefore be analyzed based on EPFM. The cases of the Hydrostatic test and the RCPB are addressed below.

For the Hydrostatic test case the LEFM results are not acceptable and the temperature considered of [ ]

does not meet the criteria to be analyzed by EPFM. Since the Hydrostatic test is a controlled event and the test temperature is chosen, a temperature of [ ] will be considered and EPFM analysis will be performed.

The Hydrostatic test case will be considered acceptable subject to meeting the EPFM requirements provided that Hydrostatic tests are performed with metal temperature of [ ] of greater.

The [ ] results listed in Table 6-1 and Table 6-2 also do not meet the LEFM criteria or the Tc criteria to be analyzed by EPFM; however, Table 6-1 and Table 6-2 have conservatively used the fluid temperature used in the Section III analysis and not the metal temperatures. For the uphill side the maximum stress intensity factor occurs at step 11I, which from Table 6-4 of Reference [22] is a time of [ ] (note the downhill side maximum is earlier in the transient). From the detailed output in "TrRT st.out" of Reference [22] at this time point the ID surface temperature is [ ] and the OD temperature is [ ] Linearly interpolating between the ID and OD, the temperature Will with reach T0 at a depth of approximately [ ]

On both the uphill and downhill side crack tip 17 is deeper than [ ] and the metal temperature will exceed To. Therefore the EPFM evaluations will be performed considering a metal temperature equal to T*.

6.4 EPFM Evaluations As noted in the previous section, the largest applied K is at the final flaw size; therefore, the EPFM evaluations will be performed for the final flaw size in accordance with the methodology described in Section 2.4 using the spreadsheets "EPFM-RG1 161_uh.xlsm" and "EPFM-RGl1161_dh.xlsm" (see Table 5-1). As discussed in the previous section all cases may be evaluated using EPFM. Table 6-3 and Table 6-4 provide the results of the EPFM evaluations. Note that when the higher safety factors provided in Section 3.1 of Code Case N-749 (Reference [3]) are used for the applied J-Integral criterion the stability check is not required; however, it is included here for completeness. As shown in Table 6-3 and Table 6-4, all cases meet the EPFM acceptance criteria. In all cases except for the [ ] transient on the downhill side the higher safety factors of Section 3.1 of Reference [3] are used; the safety factors of Section 3.2 of Reference [3] are used for the [ ]

transient on the downhill side. Details of the calculations for the limiting [ ] transient are provided in Appendix A and Appendix B, for the uphill and downhill side, respectively.

In the EPFM evaluations, the K due to pressure (K1 p) is calculated based on the Design Condition results (Table A-2 and Table B-2). The Design Condition K is interpolated or extrapolated for the desired flaw size (see Section 2.1) and multiplied by the ratio of the transient pressure to the Design Pressure.

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AREEVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 6-3: Uphill Position 17 EPFM Results Page 44

Controlled Documient Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 6-4: Downhill Position 17 EPFM Results I.-

Loading Service Level Temperature (°F)

_____Pressure (psi)

Applied J- Primary Safety Factor Integral Secondary Safety Factor Check J~0

• lkipslin)

Jo,1 (kips/in)

Margin = Jo 5 /J800 Required Margins Applied J-lntegral Check Acceptable?

Stability Check Required?

Stability Primary Safety Factor Check Secondary Safety Factor Margin = Trn~stbppftSr.Op Required Margins Stability Check Acceptable?

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary 6.5 Primary Stress Evaluation 6.5.1 Limit Load Finite Element Model The acceptance criterion of items 3.1(c) and 3.2(a)(3) of Reference [3] require that the primary stress limits of NB-3 000 (Reference [24]) are met assuming a local area reduction of the pressure retaining membrane that is equal to the area of the flaw. As described in Section 2.5, the primary stress limits for design conditions (NB-3221.1, NB-3221.2, and NB-3221.3) need not be satisfied if it can be shown by performing a limit analysis (NB-3228.1) that the applied loadings do not exceed two-thirds of the lower bound collapse load. This condition is equivalent showing that the structure does not collapse at a pressure equal to 150% of the Design Pressure (1.5x

[ ]J). In terms of finite element results plastic collapse of the structure is equivalent to numerical instability.

The boundaries of the one nozzle model utilized for stress intensity factor calculations extend beyond half the distance between adjacent penetrations in some cases. As a result, the model cannot be used directly since it would potentially be taking credit for material that is needed to reinforce other penetrations; therefore, a new model has been developed considering a 450 sector of the head with all penetrations modeled. Since this is an approximation of the symmetry of the head an additional penetration is included to conservatively insure that the modeled configuration bounds all sectors. The model penetration layout is shown with the drawing in Figure 6-1.

Each CRDM penetration is modeled with a diameter of [ ] (Reference [15]) and the vent line penetration is modeled with a diameter of [ ] corresponding to the OD of the [ ] (Reference

[25]).

In order to represent the material removed by the postulated J-groove flaws and the crack growth the following method is used:

• A cut through the head is made at a depth of [ ] (center penetration max J-groove depth from base metal [12]) + [ ] (rounded up crack growth) =[ J fr'om the ID surface. This defines the depth of the metal removed.

• A cylindrical cut is made at each CRDM penetration to slice the material up to the [ ] depth.

This volume of material is removed to represent the area of the flawed J-groove welds. A diameter of

[ ] was selected for this cut. The cross-sectional area of these slices will be compared against the areas of the postulated flaws and projected crack growth later in this calculation to verify' that this removes sufficient area.

The resulting model geometry with material removed is shown in Figure 6-2.

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ARE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzie As-Left J-Groove Analysis - Non Proprietary Figure 6-1: Limit Load Model Penetration Layout Page 47

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 6-2: Limit Load Model Geometry The overall model geometry and mesh are defined in the input file "BB_Head EighthSymm geom.inp" (see Table 5-1). The model is meshed with SOLID 185 elements with ["

] The finite element mesh utilized is shown in Figure 6-3.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 6-3: Limit Load Model Finite Element Mesh The material properties for the analysis are defined in the file "materials_LL.inp". Note that the cladding and weld metal are excluded from the model since structural credit cannot be taken for the cladding and the weld metal is postulated to be flawed. The properties are identical to those used in the explicit crack models with the exception that the material has been changed to be elastic-perfectly plastic. The value of yield strength used is based on Sm (Reference [17]) the Design Temperature of [ J and is given below.

RVCH (SA-533 Grade B Class 1) Sy = 1.5Sin = 1.5(26.7 ksi) = 40.05 ksi Pressure is applied to the ID surface of the head and to the nozzle bores, incrementally increasing in each load step. Displacements normal to the three cut faces in the model are constrained. Additionally, end cap closure loads are accounted for by distributing the total load for each nozzle over the nozzle bore. The end cap loads are calculated using the following equation where P is the current applied pressure and dbom is the bore diameter. When a nozzle falls on a cutting plane an appropriate fraction of the total load is utilized (i.e., half on the symmetry planes and one eighth for the center penetration).

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ARE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzie As-Left J-Groove Analysis - Non Proprietary The analysis is run using the input file "BB_Head_LL.inp" with results output to "BB_Head_LL.out". The output file shows the fmnal converged load step at a pressure of [ ] which is equal to [ ] times the Design Pressure, which exceeds the. requirement of 150% of the Design Pressure. The equivalent stress at the last converged load step is shown in Figure 6-4.

Figure 6-4: Equivalent Stresses at the Limit Pressure 6.5.1.1 Limit Load Methodology Verification In order to verify that the modeling methodology utilized can accurately predict limit loads, a simplified test case of a spherical shell was run, and will be compared with the theoretical solution. The same model geometry was taken prior to cutting holes for penetrations and meshed with SOLID 185 elements using similar mesh density and the same key options as the run described in 6.5.1. The model geometry and mesh are defined in the input file "Sphere geom.inp". The finite element mesh for the test model is shown in Figure 6-5. The analysis is run by the input file "SphereLL.inp" (see Table 5-1).

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A AR EVADocument No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 6-5: Finite Element Mesh for Limit Load Test Case From the output file "SphereLL.out" the final converged solution is at a pressure of [ ] The equivalent stress at the limit pressure is shown in Figure 6-6.

The theoretical limit pressure for an elastic-perfectly plastic sphere loaded by internal pressure is given by (see e.g., Reference [26])

P= 2lyIn (#*)

where P1. is the limit pressure, ay is the yield strength, Ro is the outer radius, and R, is the inner radius. For the test problem using the shell geomretry described in Section 4.1this results in Page 51

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary The finite element model predicted limit load of [ ] psig is equal to 99.5% of the theoretical solution above, which shows that the methodology utilized can accurately predict limit loads.

Figure 6-6: Limit Load Test Case Equivalent Stress at Limit Pressure 6.5.2 Calculation of Flaw Area Removed The cross-sectional areas of the material removed to represent the postulated J-groove flaws plus crack growth (see Figure 2-2 and Figure 2-3) on the uphill side and downhill side are calculated using the following equation (see for Figure 6-7 diagramc -

where x is the horizontal distance from the vessel centerline, R1 is the inside radius of the vessel, and IR2 is the radius to the depth of the metal removed. In Figure 6-7, the area removed to represent the uphill flaw is indicated by area A2 and the downhill flaw by area A3. The integral is evaluated using the following solution from a table of integrals (e.g., Reference [27])

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 6-7: Area Calculation Diagram I

The area removed from the ANSYS model is calculated in the spreadsheet "BB_Weld_Removed_Area.xlsx" (see Table 5-1) for the center penetration (1) and the outermost penetrations (74-78) since these will bound the minimum (center) and maximum (outermost) areas. The resulting areas removed from the ANSYS model are shown in Table 6-5.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table 6-5: Model Areas Removed by the Cutouts to Represent Postulated Flaws i.... ....

........... .. .... . ........ .. ....T.... .. ... .. .. ...... .o...z lesNzz e

______ 74

_______ 75 iGeometry Inputs I

Ri (RVCH inner radius to base metal) inches R2 (Ri + i-groove depth + crack growth) !inches dbore (nozzle bore diameter) inches Cx (x distance from RVCH CL to Nozzle CL) inches Cy (y distance from RVCH CL to Nozzle CL) inches Rh = (Cx^2+Cy^2)^0.5 inches Li (distance from nozzle CL to cut radius) inches xmax = Rh-dbe2

[

L2 (distance from nozzle CL to cut radius)

Calculate Area, A2 (Uphill Weld Area Removed) xmin = Rh-Li boe/2 Calculate Area, A3 (Downhill Weld Area Removed) inches

]inches quar inces jinches_

Tm xmin = Rh+dbore/2 Jinches xmax = Rh+L2 linches A3 Jsquare inches _

iCalculate total weld cross sectional area removed in model IA2 +A3 I

Iscuare inches I " I For the outermost penetration the initial flaw areas are measured from the ANSYS workbench model to be

[ j in2 on the uphill side and [ J on the downhill side (see Figure 6-8). For the center penetration the initial flaw area on both the uphill and downhill side is conservatively estimated by taking rectangle bounding the J-groove and butter (Reference [12]).

[

The area with crack growth is estimated by taking the square root of the area, adding a rounded up crack growth of [ ] (see Table 6-1 and Table 6-2), and squaring the result as illustrated schematically in Figure 6-9. The results of the calculation are shown in Table 6-6.

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure 6-9: Crack Growth Area Calculation Table 6-6: Flaw Area Comparison Nozzle Uphil WeldArea Downhill Weld Area n

i21 II Center Nozzle Outermost Nozzle ffiff f j Max Crack Growth inches ((ij ))f(( 1 Uphill Weld Area with Max Crack Growth in2 [ 1 Downhill Weld Area with Max Crack Growth in2 f i [ A Uphill Area Removed, A2 in2 1 Downhill Area Removed, A3 in2 [j[ [ ]

Uphill Area Removed - Uphill Area with Max CG in2 Jj Downhill Area Removed - Downhill Area with Max CG in2 [. L. [1 ]...

As shown above in Table 6-6 the areas removed from the ANSYS model (A2 and A3) exceeds the area including crack growth in all cases; therefore, sufficient area has been removed in the Limit Load model to account for the area of the flaw and crack growth.

Since sufficient area has been removed and the limit pressure exceeded 150% of the Design Pressure, the primary stress criteria in items 3.1 (c) and 3.2(a)(3) of Code Case N-749 (Reference [3 ]) are satisfied.

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

7.0 CONCLUSION

S A fatigue crack growth and fracture mechanics evaluation of the worst-case flaws in the as-left J-groove weld and buttering at the worst-case penetration location has been performed. Based on a combination of linear elastic and elastic-plastic fracture mechanics the postulated flaws are shown to be acceptable for the remaining life utilizing the safety factors in Table 1-1, and the lower bound J-R Curve from Regulatory Guide 1.161.

Limitation: The minimum metal temperature for performing a Hydrostatic test at any time after an IDTB repair has been made is [ ]

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

8.0 REFERENCES

1. AREVA Document 08-9232121-000, "Byron Units 1 and 2, and Braidwood Units 1 and 2, RVCH Nozzle Penetration Modification."

2. ASME Boiler and Pressure Vessel Code, Section Xl, "Rules for Inservice Inspection of Nuclear Power Plant Components", 2001 Edition including Addenda through 2003.

3. Cases of the ASME Boiler and Pressure Vessel Code, Case N-749, "Alternative Acceptance Criteria for Flaws in Ferritic Steel Components Operating in the Upper Shelf Temperature Range,"Section XI, Division I.

4. Letter, Balwant K. Singal (NRC) to Randall K. Edington (APS), "Palo Verde Nuclear Generating Station, Unit 3- Request for Additional Information RE: Relief Request 52, Alternative to ASME Code,Section XI Requirements for Flaw Evaluation, Flaw Characterization, and Successive Examinations (TAC NO.

MF4169)," NRC ADAMS Accession Number ML14330A510, December 4, 2014.

5. T.L. Anderson, "Fracture Mechanics - Fundamentals and Applications", CRC Press, 1991.

6. AREVA Document 38-2201373-000, "Byron Units l&2 and Braidwood Units l&2 Proprietary Information."

7. AREVA Drawing 02-185313E-00, "Closure Head Assembly."

8. AREVA Drawing 02-185314E-00, "Closure Head Sub-Assembly Sheet 1."

9. AREVA Drawing 02-185344E-00, "Closure Head Assembly."

10. AREVA Drawing 02-185345E-00, "Closure Head Sub-Assembly Sheet 1."

11. AREVA Drawing 02-184573E-04, "Closure Head Assembly."

12. AREVA Drawing 02-184574E-06, "Closure Head Sub-Assembly Sheet 1."

13. AREVA Drawing 02-185282E-00, "Closure Head Assembly."

14. AREVA Drawing 02-185283E-01, "Closure Head Sub-Assembly Sheet 1."

15. AREVA Drawing 02-9232823E-000, "Byron Units 1 and 2 / Braidwood Units 1 and 2 CRDM, SPARE &

RVLIS Penetration Modification."

16. AREVA Drawing 02-9232824E-000, "Byron Units 1 and 2 / Braidwood Units 1 and 2 Thermocouple Column Penetration Modification."

17. ASME Boiler and Pressure Vessel Code,Section III, "Nuclear Power Plant Components," Division 1, 1971 Edition including Addenda through Summer 1973

18. AREVA Document 51-9234885-000, "Exelon Byron and Braidwood RVCH Original Material and Fabrication Review."

19. ASTM E185-10, "Standard Practice for Design of Surveillance Programs for Light-Water Moderated Nuclear Power Reactor Vessels."

20. Regulatory Guide 1.161, "Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less than 50 ft-lb", June 1995.

21. AREVA Document 32-9233779-000, "Weld Residual Stress Analysis of Byron 1 & 2, and Braidwood 1

& 2 RVCH Nozzle/Penetration Repair"

22. AREVA Document 32-9233803-000, "ASME Section III Analysis of Byron/Braidwood RVCH Nozzle and Penetration Modification"

23. ANSYS Finite Element Computer Code, Version 14.5, ANSYS Inc., Canonsburg, PA.

24. ASME Boiler and Pressure Vessel Code,Section III, "Rules for Construction of Nuclear Facility Components", Division 1,2001 Edition including Addenda through 2003.

25. AREVA Drawing 02-1853 18E-0l, "Closure Head Attachments."

26. Hill, R., "The Mathematical Theory of Plasticity," Oxford University Press, 1950.

27. Avalone, E.A., Baumeister, T., Sadegh, A.M., (Eds.) "Marks' Standard Handbook for Mechanical Engineers," Eleventh Edition, McGraw Hill.

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary APPENDIX A: UPHILL SIDE FLAW EVALUATIONS This appendix presents the fatigue crack growth and flaw evaluations for the uphill side flaw.

Table A-I: SIFs for Uphill Side - Welding Residual Stress Page A-I

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A R EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table A-2: SIFs for Uphill Side - Design Condition __

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

__Table A-7: Fatigue Crack Growth for [ ] (Uphill)

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-Table A-9: Fatigue Crack Growth for [ ] (Uphill)

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-Table A-IO0: Fatigue Crack Growth for [ ] (Uphill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Anelysis - Non Proprietary Table A-Il : Fatigue Crack Growth [ ] (Uphill)

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AREEVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

__Table A-12: Fatigue Crack Growth for [ ] (Uphill)

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-Table A-13: Fatigue Crack Growth for [ ] (Uphill)

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AR EVA Document No. 32-9244434-000 Byron and Braidiwood RVCH Nozzle Aa-Left J-Groove Analysis - Non Proprietary Table A-14: Fatigue Crack Growth for [ ] (Uphill)

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-Table A-16: Fatigue Crack Growth for [ ] (Uphill)

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__Table A6-19: Fatigue Crack Growth for [ 3(Uphill)

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ARE~VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table A-21: Fatigue Crack Growth for [ ] (Uphill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table A-22: EPFM Evaluation for [ ] (Uphill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Figure A-I: J-T Diagram for [

I (Uphill)3 Page A-23

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ARE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary APPENDIX B: DOWNHILL SIDE FLAW EVALUATIONS This appendix presents the fatigue crack growth and flaw evaluations for the downhill side flaw.

Table B-I: SIFs for Downhill Side - Welding Residual Stress Page B-I

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AREEVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table B-2: SIFs for Downhill Side - Design Condition Page B-2

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ARE VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table B-5: SlFs for Downhill Side - [ I Page B-5

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table B-6: SIFs for Downhill Side - [ ]

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AR =VA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table B-7: Fatigue Crack Growth for [] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis- Non Proprietary Table B-8: Fatigue Crack Growth for [ ] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

-Table B-9: Fatigue Crack Growth for [ I (Downhill)

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,AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

-Table B-1O: Fatigue Crack Growth for [ ] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron end Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

__Table B-Il: Fatigue Crack Growth for [ ] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis- Non Proprietary

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

__Table B-14: Fatigue Crack Growth for [ ] (Downhill)

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AR EVADouetN.3-24300 Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary Table B-15: Fatigue Crack Growth for [ ] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

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__Table B-It: Fatigue Crack Growth for E 3 (Downhill)

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AIR EVA Document No. 32-9244434-000 Byron and Bra idwood RVCH Nozzle As-Left J-Groove Analysis- Non Proprietary

__Table B-19: Fatigue Crack Growth for [ ] (Downhill)-

Psge 2-19

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

__Table B-20: Fatigue Crack Growth for [ ] (Downhill)

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AR EVA Document No. 32-9244434-000 Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis - Non Proprietary

-Table B-21: Fatigue Crack Growth for [ ] (Downhill)

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ATTACHMENT 6 Areva Inc, Affidavit for Areva calculation, "IDTB RVCH Repair Weld Anomaly Fracture Mechanics Stress Analysis (32-9237284-000)" and "IDTB RVCH Repair Fracture Mechanics Stress Analysis (32-9236713-000)," July 29, 2015

Controlled Document AFFIDAVIT COMMONWEALTH OF VIRGINIA )

) SS.

CITY OF LYNCHBURG )

1. My name is Gayle Elliott. 1am Manager, Product Licensing, for ARE VA Inc.

(ARE VA) and as such I am authorized to execute this Affidavit.

2. I am familiar with the criteria applied by AREVA to determine whether certain AREVA information is proprietary. I am familiar with the policies established by ARE VA to ensure the proper application of these criteria.

3. I am familiar with the AREVA information contained in Calculation Summary Sheets (CSS) 32-923671 3-00i, entitled, "Byron and Braidwood RVCH Nozzle As-Left J-Groove Analysis," and 32-9237284-001, entitled, "Byron/Braidwood RVCH Nozzle IDTB Repair Weld Anomaly," both dated July 2015 and referred to herein as "Documents." Information contained in these Documents has been classified by ARE VA as proprietary in accordance with the policies established by ARE VA Inc. for the control and protection of proprietary and confidential information.

4. These Documents contain information of a proprietary and confidential nature and is of the type customarily held in confidence by AREVA and not made available to the public. Based on my experience, I am aware that other companies regard information of the kind contained in these Documents as proprietary and confidential.

5. These Documents have been made available to the U.S. Nuclear Regulatory Commission in confidence with the request that the information contained in these Documents be withheld from public disclosure. The request for withholding of proprietary information is made in accordance with 10 CFR 2.390. The information for which withholding from disclosure

Controlled Document is requested qualifies under 10 CFR 2.390(a)(4) "Trade secrets and commercial or financial information."

6. The following criteria are customarily applied by AREVA to determine whether information should be classified as proprietary:

(a) The information reveals details of AREVA's research and development plans and programs or their results.

(b) Use of the information by a competitor would permit the competitor to significantly reduce its expenditures, in time or resources, to design, produce, or market a similar product or service.

(c) The information includes test data or analytical techniques concerning a process, methodology, or component, the application of which results in a competitive advantage for ARE VA.

(d) The information reveals certain, distinguishing aspects of a process, methodology, or component, the exclusive use of which provides a competitive advantage for AREVA in product optimization or marketability.

(e) The information is vital to a competitive advantage held by ARE VA, would be helpful to competitors to AREVA, and would likely cause substantial harm to the competitive position of ARE VA.

The information in these Documents is considered proprietary for the reasons set forth in paragraphs 6(c), 6(d) and 6(e) above.

7. In accordance with AREVA's policies governing the protection and control of information, proprietary information contained in.these Documents has been made available, on a limited basis, to others outside ARE VA only as required and under suitable agreement providing for nondisclosure and limited use of the information.

8. AREVA policy requires that proprietary information be kept in a secured file or area and distributed on a need-to-know basis.

Controlled Document

9. The foregoing statements are true and correct to the best of my knowledge, information, and belief.

41__*

SUBSCRIBED before me this *. 9' day of LJz*z. 2015.

Danita R. Kidd NOTARY PUBLIC, COMMONWEALTH OF VIRGINIA MY COMMISSION EXPIRES: 12/31/16 Reg. # 205569