RC-12-0170, LTR-PAFM-12-137-NP, Rev. 1, Technical Basis for Westinghouse Embedded Flaw Repair for V. C. Summer, Unit 1, Reactor Vessel Head Penetration Nozzles.
| ML12319A256 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 11/05/2012 |
| From: | Ching Ng Westinghouse |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| CR-12-04775, RC-12-0170 LTR-PAFM-12-137-NP, Rev 1 | |
| Download: ML12319A256 (17) | |
Text
Document Control Desk CR-12-04775 RC-12-0170 Page 1 of 17 VIRGIL C. SUMMER NUCLEAR STATION (VCSNS)
DOCKET NO. 50-395 OPERATING LICENSE NO. NPF-12 Attachment 3 LTR-PAFM-12-137-NP, Revision 1
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-12-0170 Page 2 of 17 LTR-PAFM-12-137-NP Revision 1 Technical Basis for Westinghouse Embedded Flaw Repair for V. C. Summer Unit 1 Reactor Vessel Head Penetration Nozzles November 2012 Author: C. K.Ng*
Piping Analysis and Fracture Mechanics Verifier: A. Udyawar*
Piping Analysis and Fracture Mechanics Approved: S. A. Swamy*
Manager, Piping Analysis and Fracture Mechanics
- Electronically approved records are authenticated in the Electronic Document Management System
©2012 Westinghouse Electric Company LLC All Rights Reserved O Westinghouse
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-1 2-0170 Page 3 of 17 Record of Revisions Revision Date Description of Changes 0 October 2012 Original Issue 1 November 2012 Incorporate NRC comments and information from the latest NDE data sheet Note :
Changes made in the latest revision are indicated by a single line in the right hand margin as shown here.
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Document Control Desk Attachment 3 CR-I12-04775 RC-12-0170 Westinghouse Non-Proprietary Class 3 Page 4 of 17 1 INTRODUCTION As a part of the inspection and contingence repair efforts associated with the reactor vessel closure head inspection program at V. C. Summer Unit 1, engineering evaluations were performed to support plant specific use of the Westinghouse embedded flaw repair process to repair unacceptable flaws detected in the head penetration nozzles during the Fall 2012 outage.
The embedded flaw repair process involves depositing a weld material, which is Primary Water Stress Corrosion Cracking (PWSCC) resistant, over the detected flaw on the outside surface of the penetration nozzle of interest as well as over the wetted surface of the attachment J-groove weld. As a result, the surface flaw becomes a sub-surface flaw and is no longer exposed to the primary water environment. The methodology used is based on extensive analytical work completed by the Westinghouse Owners Group, currently the Pressurized Water Reactor Owners Group (PWROG), and a large collection of test data obtained under the sponsorship of Westinghouse, Babcock & Wilcox (B&W) and the former Combustion Engineering Owners groups (CEOG), as well as the Electric Power Research Institute (EPRI). The technical basis of the embedded flaw repair process is documented in WCAP-1 5987-P Revision 2-P-A [1] and has been reviewed and accepted by the Nuclear Regulatory Commission (NRC) in the United States. In the NRC Safety Evaluation Report that was incorporated in WCAP-1 5987-P Revision 2-P-A, the NRC staff concluded that, subject to the specified conditions and limitations, the embedded flaw repair process described in WCAP-15987-P provides an acceptable level of quality and safety. The staff also concluded that WCAP-1 5987-P is acceptable for referencing in licensing applications.
In this report, the technical basis and the flaw evaluation results to support the use of the Westinghouse embedded flaw repair process for head penetration nozzle number 19, 31, 37 and 52 with unacceptable outside surface flaws in the vicinity of the J-groove weld toes are provided. Engineering evaluations were performed to determine the maximum acceptable initial flaw sizes that can be left behind in a repaired penetration nozzle which would satisfy the ASME Section Xl requirements [2]. The purpose of this report is to provide plant-specific technical basis for.the use of the embedded flaw repair process and to confirm that V. C. Summer Unit 1 meets the criteria for application of the embedded flaw repair process stated in Appendix C of WCAP-1 5987-P [1].
2 TECHNICAL BASIS FOR APPLICATION OF EMBEDDED FLAW REPAIR PROCESS TO HEAD PENETRATION NOZZLES This section provides a discussion on the technical basis for the use of embedded flaw repair process for head penetration nozzle number 19, 31, 37 and 52 with unacceptable outside surface flaws. Such a repair involves depositing several layers of Alloy 5:2/52M weld material over the flaw on the outside surface of the penetration nozzle of interest below the J-groove weld as well as the wetted surface of the attachment J-groove weld. Since the Alloy 52/52M repair weld material is PWSCC resistant, the detected surface flaw in the head penetration nozzle of interest is then shielded from the primary water environment and is no longer susceptible to primary water stress corrosion cracking.
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Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-12-0170 Page 5 of 17 For the repair of the unacceptable outside surface flaws in head penetration nozzle number 19, 31, 37 and 52, at least three layers of Alloy 52/52M material are deposited (3600 full circumference) covering the entire wetted surface of the attachment J-groove weld. The repair weld extends at least 0.5 inch past the interface between the J-groove weld buttering and stainless steel cladding as well as covering the entire outside surface of the head penetration nozzle with at least two layers of Alloy 52/52M material. A schematic of the! repair configuration for the repaired outside surface flaw is illustrated in Figure 2-1.
Flaw evaluations were performed based on the flaw sizes and shapes remaining in the repaired head penetration nozzles of interest to demonstrate that the left behind flaws are acceptable for continued operation. The as-found flaw parameters for penetration nozzle number 19, 31, 37 and 52 are shown below in Table 2-1. Since all the indications located on the outside surface of the penetration nozzles in the vicinity of the attachment J-groove weld toes are skewed with respect to the axis of the penetration nozzles, both axial and circumferential flaws are assumed.
Table 2-1 As-Found Flaw Parameters in V. C. Summer Unit 1 Head Penetration Nozzles Flaw Flaw Flaw Flaw Indications Orientation Length (in) Depth Location (in)
Penetration No. 19 Circumferential 1.36 Outside Surface/Downhill (Indications #1 ) Axial 0.72 Side Penetration No. 31 Circumferential 0.16 Outside Surface/Downhill 0.122 Side (Indication #1) Axial 0.52 Penetration No. 31 Circumferential 0.16 Outside Surface/Downhill (Indication #2) Axial 0.36 0.177 Side Penetration No. 31 Circumferential 0.26 Outside Surface/Downhill 0.256 Side (Indication #3) Axial 0.61 Penetration No. 37 Circumferential 0.31 Outside Surface/Downhill 0.249 Side (Indication #1) Axial 0.76 Penetration No. 37 Circumferential 0.10 0.214 Outside Surface/Downhill Side (Indication #2) Axial 0.56 Penetration No. 37 Circumferential 0.16 0.294 Outside Surface/Downhill Side (Indication #3) Axial 0.52 Penetration No. 52 Circumferential 0.47 Outside Surface/Downhill (Indication #2) Axial 0.32 0.279 Side Penetration No. 52 Circumferential 0.21 Outside Surface/Downhill 0.132 Side (Indication #3) Axial 0.12 Page 4 of 16
Document Control Desk Attachment 3 CR-I12-04775 RC-12-01470 Westinghouse Non-Proprietary Class 3 Page 6 of 17 Based on the Ultrasonic Testing (UT) and Penetrant Testing (PT) results at the regions of interest for penetration nozzle number 19, 31, 37 and 52, there are no surface connected indications in the J-groove weld and the detected indications are solely in the base metal of the nozzles. Each of the detected UT indications starts in the nozzle below the toe of the weld.
Some of the measured indication lengths extend slightly above the toe of the weld, but the measurement technique overestimates the lengths due to the large beam spread inherent with tip diffraction probes. The thinnest portion of the weld is the ground contour that blends the weld to the nozzle, so any propagation from the nozzle base metal into the weld metal would be expected to start at that point. In order to determine if the indications grew into the weld metal at this contoured section of the weld, a PT was performed on the J-groovw weld and adjacent nozzle. Since none of the PT indications continued into the J-groove weld, it was concluded that the indications only involve the base metal of the nozzle. The technical basis for the embedded flaw repair provided is therefore focused on the indications in the base metal of the penetration nozzles of interest.
2.1 EVALUATION PROCEDURE AND ACCEPTANCE CRITERIA Rapid, non-ductile failure is possible for ferritic materials at low temperatures, but is not applicable to the nickel-base alloy head penetration nozzle material such as Alloy 600. Nickel-base alloy material is a high toughness material and plastic collapse would be the dominant mode of failure. Therefore the evaluation procedures and acceptance criteria for indications in austenitic piping contained in paragraph IWB-3640 of ASME Section Xl Code [2] are applicable for evaluation of flaws in the head penetration nozzles. The evaluation procedure used is consistent with those in Appendix C of WCAP-1 5987-P [1] and summarized below:
2.1.1 Acceptance Criteria for Axial Flaws For axial flaws, the allowable flaw depth for a given flaw length can be determined from the following expression:
1-at.
oh Cf h SF m _(a)/ M where 1.61
/),2]1 2
M22=1 +t4Rrnt _
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Document Control Desk Attachment 3
~CR-i12-04775 RC-12-0170 Westinghouse Non-Proprietary Class 3 Page 7 of 17 and
=f Flow stress = 2 (Average of Ultimate and Yield Strengths)
'h = PRm/t t = Total Flaw Length a = Flaw Depth Rm = Mean Radius of Penetration Nozzle t = Wall Thickness of Penetration Nozzle P = Internal Pressure SFm = Safety Factor for membrane stress:
2.7 for Level A Service Loading 2.4 for Level B Service Loading 1.8 for Level C Service Loading 1.3 for Level D Service Loading The limits of applicability of this equation are a/t < 0.75 and t < ft alow, where 05 1] 0.5 tallow = 1.58(Rrmt) [(Cf /Oh) 2-This limit is chosen such that surface flaws would remain below the critical size based on the plastic collapse condition if they should grow through the wall.
2.1.1 Acceptance Criteria for Circumferential Flaws For circumferential flaws, the following relationship between the applied loads and flaw depth at incipient collapse given by equations in ASME Section XI Article C-5000 [2] is used:
Y =- 2--f[2sinp _a sine]
13* Tr-t o',.)"
where:
b = Bending stress at incipient plastic collapse 0 = One-half of the final flaw angle 13 = Angle to neutral axis of penetration nozzle a/t = Flaw depth to wall thickness ratio Su + S C*f = Flow stress = U2+' (Average of Ultimate and Yield Strengths) am = Applied membrane stress Page 6 of 16
Document Control Desk Attachment 3 CR-i12-04775 RC-12-0170 Westinghouse Non-Proprietary Class 3 Page 8 of 17 The allowable bending stress, Sc, is as follows, which is used to calculate the maximum allowable end-of-evaluation period flaw sizes and the limit of applicability of this equation is a/t <
0.75.
S Fb
-mm[1m.
where Sc = Allowable bending stress for penetration nozzle CYm = Applied membrane stress SFm = Safety factor for membrane stress
= 2.7, 2.4, 1.8 and 1.3 for Service Level A, B, C, and D respectively SFb = Safety factor for bending stress
= 2.3, 2.0, 1.6, and 1.4 for Service Level A, B, C, and D respectively 2.2 Methodology The flaw evaluation considered that the embedded flaw repair process is used to seal the unacceptable flaws from further exposure to the primary water environment. The evaluation began with the determination of the maximum allowable end-of-evaluation period flaw sizes based on the acceptance criteria described in Section 2.1 for the repaired penetration nozzles.
With the embedded flaw repair process, the only mechanism for future sub-critical crack growth is fatigue. The maximum initial embedded flaw size that can remain in a repaired penetration nozzle using the embedded flaw repair process can then be determined by subtracting the predicted fatigue crack growth for future plant operation from the maximum allowable end-of-evaluation period flaw size. This maximum initial allowable embedded flaw size is then compared with the left-behind flaw in the repaired head penetration nozzle of interest to demonstrate acceptability. The following provides a discussion of the loading conditions, geometry, thermal transient stress and fatigue crack growth analysis used in the development of the plant specific technical basis for the embedded flaw repair process.
2.2.1 Geometry and Source of Data There are many penetration nozzles in the reactor vessel upper head. The outermost penetration nozzles (46.00 intersection angle) were selected for thermal transient and residual stress analysis because the stresses in the outermost penetration nozzles are more limiting and can be used to conservatively represent those at penetration nozzle number 19, 31 and 37 and 52.
The dimensions of all the V. C. Summer Unit 1 penetration nozzles are identical, with a 4.00 inch nominal outside diameter and a nominal wall thickness of 0.625 inch [3]. The distributions of residual, thermal transient and pressure stresses in the upper head penetration nozzle were obtained from the detailed three-dimensional plant specific elastic-plastic finite element analyses [4]. The through-wall stress distributions from the finite element analyses were used Page 7 of 16
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-1 2-0170 Page 9 of 17 to determine the fatigue crack growth. The resulting crack growth is then used to determine the maximum allowable initial flaw sizes for the left-behind flaws in the repaired penetration nozzles of interest.
2.2.2 Maximum Allowable End-of-Evaluation Period Flaw Size Determination The requirement for evaluating a flaw using the rules of ASME Section XI is that the loading for normal/upset conditions as well as emergency/faulted conditions be considered. This is necessary because, as discussed in Section 2.1, different safety margins are used for the normal/upset and emergency/faulted conditions. A lower safety factor is used to reflect a lower probability of occurrence for the emergency/faulted conditions.
Plastic collapse is the governing mode of failure for the head penetration nozzles because the high fracture toughness of the nickel base alloy (Alloy 600) material would prevent brittle fracture from occurring. Therefore, it is not necessary to consider the effects of secondary stresses resulting from thermal transient stresses and residual stresses. The governing loading for determining the maximum allowable end-of-evaluation period flaw sizes is therefore those due to internal pressure and other applicable external mechanical loads for the normal, upset, emergency and faulted conditions.
2.2.3 Thermal Transients Used in Fatigue Crack Growth Analysis For the fatigue crack growth prediction, the effects of secondary stresses resulting from thermal transient and residual stresses must also be considered. The thermal transients that occur in the upper reactor vessel head region are relatively mild. The normal and upset thermal transients considered in the fatigue crack growth calculation are shown in Table 2-2 [5].
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Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-12-0170 Page 10 of 17 Table 2-2 Reactor Coolant System Transients for V. C. Summer Unit 1 Design Transients Design Cycles Normal Conditions Heat Up/Cooldown 200 Plant Loading/Unloading 18300 Step Load Increase/Decrease 2000 Large Step Load Decrease with Steam Dump 200 Turbine Roll Test 80 Feedwater Heaters Out of Service 40 Steady State Fluctuation (Initial) 150000 Steady State Fluctuation (Random) 3000000 Upset Conditions Loss of Load 200 Loss of Flow 80 Loss of Power 40 Reactor Trip From Full Power 400 Inadvertent Auxiliary Spray 10 Excessive Feedwater Flow 30 Operating Basis Earthquake 400 2.2.4 Crack Tip Stress Intensity Factor One of the key elements in a crack growth analysis is the crack driving force or crack tip stress intensity factor, K1. This is based on the equations available in the public literature. It should be noted that the flaws in the repaired penetration nozzles are conservatively assumed to be surface flaws even though the flaws are embedded after the repair.
For a part-through wall surface flaw, the stress profile is approximated by a fourth order polynomial as follows:
a(x) = A0 + Ajx + A2x2 + A3x 3 + A4x4 where:
x Distance into the wall from the free surface a Stress perpendicular to the plane of the crack Ai Coefficients of the 4t" order polynomial fit, i = 0, 1, 2, 3, 4 For a surface flaw in the penetration nozzle, the stress intensity factor expression from API-579
[6] is used. The stress intensity factor K, (() can be calculated anywhere along the crack front, Page 9 of 16
Document Control Desk Attachment 3 CR-i12-04775 RC-12-0170 Westinghouse Non-Proprietary Class 3 Page 11 of 17 where 4 is the elliptical angle of a point on the crack front being evaluated. The following expression is used in calculating K, (k).
K,= -'Y Gj (a/c, a/t, t/R, ý) A, aj Q -0.j=0 The magnification factors Go, G 1, G 2, G3 and G 4 can be found in [6]. The parameter "a" is the crack depth, "c" is the half crack length, "t" is the wall thickness, "R" is the mean radius, "f" is the parametric angle of the elliptical crack, and "Q" is the shape factor.
2.2.5 Fatigue Crack Growth Analysis The applied loads used in the fatigue crack growth analysis include pressure, thermal transients and residual stresses. The normal and upset thermal transients considered in the fatigue crack growth analysis are shown in Table 2-2. The transient cycles are distributed evenly over the entire plant design life. The crack tip stress intensity factor range, AK, which controls fatigue crack growth, depends on the geometry of the crack, its surrounding structure and the range of applied stresses in the region of the crack. Once AK is calculated, the fatigue crack growth due to a particular stress cycle can be determined using a crack growth rate reference curve applicable to the head penetration nozzle material.
The fatigue crack growth rate (CGR) reference curve used in the fatigue crack growth analysis for the Alloy 600 material in air environment is based on that in NUREG/CR-6721 [7] and is shown below.
da S
-- = CS AK4 1 dN 18 2 21 3 C=4.835x 10- 14 +1.622x 10- 16 T-1.490x 10- T +4.355x10- T 22 SR = [1 - 0.82R-where:
T = Temperature of the Transient (°C)
AK = Stress Intensity Factor Range (MPa i-m)
R = Stress Ratio (Kmin/Kmax) da = Fatigue crack growth rate (meters/cycle) dN Page 10 of 16
Document Control Desk Attachment 3 CR-i12-04775 RC-12-0170 Westinghouse Non-Proprietary Class 3 Page 12 of 17 Once the incremental crack growth corresponding to a specific transient for a given time period is calculated, it is added to the previous crack size, and the analysis continues to the next time period and/or thermal transient assuming the flaw shape remains constant. The procedure is repeated in this manner until all the significant design thermal transients and cycles known to occur in a given period of operation have been analyzed. For conservatism, R=1 is used in the fatigue crack growth analysis.
2.3 Flaw Evaluation Results The maximum allowable end-of-evaluation period axial and circumferential flaw depths for the V.
C. Summer Unit 1 penetration nozzles of interest are provided for various flaw aspect ratios (flaw depth/flaw length) in Table 2-3. The maximum allowable initial axial and circumferential flaw sizes accounting for fatigue crack growth of 40 years after the repair are shown in Figures 2-2 and 2-3 respectively. The maximum allowable initial flaw sizes are obtained by subtracting the fatigue crack growth for 40 years of service life after the repair from the maximum allowable end-of-evaluation period flaw sizes. Figure 2-4 shows the fatigue crack growth for hypothetical axial and circumferential flaws with initial flaw depth and aspect ratios (flaw depth/flaw length) that bound those for the left-behind flaws in repaired penetration nozzle number 19, 31, 37 and
- 52. The fatigue crack growth curves shown in Figure 2-4 would bound the fatigue crack growth curves for each of the indications in the repaired penetration nozzles of interest. The fatigue crack growth results shown in Figure 2-4 shows that it would take more than 40 years to reach the maximum allowable end-of-evaluation period flaws sizes shown in Table 2-3. This is consistent with the results shown in Figures 2-2 and 2-3 where the left-behind flaw sizes in the repaired penetration nozzles of interest are below the maximum allowable initial flaw size curves.
As shown in Figures 2-2 and 2-3, the respective maximum allowable initial axial and circumferential flaw sizes are larger than the left-behind flaws in the repaired penetration nozzle number 19, 31, 37 and 52. Therefore, all the repaired flaws are acceptable for continued operation for at least 40 years after the repair. It should be noted in Figures 2-2 and 2-3, the aspect ratios (flaw depth/flaw length) for indications in the penetration nozzles are set to a maximum of 0.5 in accordance with the ASME Section Xl Code.
Table 2-3 Maximum Allowable End-of-Evaluation Period Flaw Sizes (Percentage of Nominal Wall Thickness)
Aspect Ratio Circumferential Flaw Axial Flaw (Depth/Length) 0.20 57% 75%
0.33 73% 75%
0.50 75% 75%
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Document Control Desk Attachment 3 CR-I12-04775 RC-1 2-0170 Westinghouse Non-Proprietary Class 3 Page 13 of 17 3.0 Conclusions The unacceptable outside surface circumferential flaws are isolated from the primary water environment using the Westinghouse embedded flaw repair process. Primary water stress corrosion is no longer a credible degradation mechanism and fatigue is the only credible crack growth mechanism. The left behind flaws in the repaired head penetration nozzle number 19, 31, 37 and 52 have been shown to be acceptable for continued operation for at least 40 years after the repair. These upper head penetration nozzles will be inspected every refueling outage following the repair. It is therefore technically justified to use the embedded flaw repair process as the repair technique for the reactor vessel head penetration nozzles with the unacceptable outside surface flaws since the criteria for application of such a process as stated in Appendix C of WCAP-1 5987-P is met.
4.0 References
- 1. Westinghouse WCAP-15987-P, Revision 2-P-A, "Technical Basis for the Embedded Flaw Process for Repair of Reactor Vessel Head Penetrations,"
December 2003. (Westinghouse Proprietary Class 2)
- 2. ASME Section Xl Code:
- a. ASME Boiler & Pressure Vessel Code, 1998 Edition through 2000 Addenda,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components.
- b. ASME Boiler & Pressure Vessel Code, 2007 Edition with 2008 Addenda,Section XI, Rules for Inservice Inspection of Nuclear Power Plant Components.
- 3. Chicago Bridge & Iron Company Drawing No. 40, Contract No. 71-2631, "157" PWR Control Rod Drive Mechanism Housings Details," Revision 6.
- 4. Dominion Engineering, Inc. Report C-8849-00-01 Rev. 0, "V.C. Summer RPV Head CRDM Nozzle Welding Residual Stress plus Transient Analysis". (Dominion Engineering Inc. Proprietary Document)
- 5. Design Specification DS-MRCDA-09-10, Revision 0, Equipment: Reactor Vessel -
Virgil C. Summer Nuclear Station Addendum to Equipment Specification 679105 Rev. 2. (Westinghouse Proprietary Class 2)
"Fitness-For-Service," June 2007.
- 7. NUREG/CR-6721, ANL-01/07, "Effects of Alloy Chemistry, Cold Work, and Water Chemistry on Corrosion Fatigue and Stress Corrosion Cracking of Nickel Alloys and Welds," April 2001.
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Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-1 2-0170 Page 14 of 17 Outside Surface Flaw iI Alloy 52/52M Repair Weld Figure 2-1 A Schematic of the Repair Configuration for the Outside Surface Flaw Note: The outside surface flaw shown in the figure is for repair configuration illustration purposes and does not intend to represent the actual outside surface flaws detected at V. C. Summer Unit 1 Page 13 of 16
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-12-0170 Page 15 of 17 0.8 T
0.7 Maximum Allowable Initial Axial Flaw Size Curve For ..... --------
Repaired Penetration Nozzles with 40 Years of Service Life ---
0.6
... *tain
- ------- ---. . 1d # & -- ! - i -: -=* -?: -:i -Penetration
. .i -
- 37- --Ind. - #3 a 0.294 1 0.52" I 0.5 1=.Penetration rPenetration 19 Ind. #1&2 a0..0.2 4 9...007.256",1 Pntain3 d#
31nd. #3 0.61.
I I
0.4 Penetrationn37 #2 Ind.
S03 a a 0.a70214 0.056 0.3
.. iPenetration31 d.#2 09 00367 ,01771 II 0.2 SPenetration 317------ -
d #1------- - -- ---- - -- - - P enetration 31I5 d. # 3 012 I
017" 0132=0.1 05261 0.1 0
0.2 0.25 0.3 0.35 0.4 0.45 0.5 Flaw Depth to Flaw Length Ratio (a/I)
Figure 2-2 Maximum Allowable Initial Axial Flaw Sizes for Repaired Penetration Nozzles Page 14 of 16
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-1 2-0170 Page 16 of 17 I
0.8 i
I~ _______
7- 71 0.7 Maximum Allowable Initial Circumferential FlawSize Curve For Repaired Penetration Nozzles with 40 Years of Service Ufe
- -i i -i -i - - J i - - i -
L- ---.. -
0.6 Penetration 37 Ind. #3
- --, - -- --- --- - ---- - --- - --- --- a= 0.294" I =0.157"
- - I- - - I- - - - - - T- - - -- - - -- -- --- -- ---
- -T --- --- I I P netration52 nd. #2 S0.5 0 279"1 =0.471" A
--- --- ------- ------------- -- ---- Penetra tion 31 Ind. #3 - I a=0.2256" 1 = 0.262" I
-------------- ----------- T ---
--- ! I !-*- --
0.4 Penetration 19 Ind. #1&2
--- --- Penetration 37 Ind. #1
a= 0.283"l 1.361* ------- I--------
a= 0.249" 1= 0.314" 0
Penetration 37 Ind. #2 0.3 a =0.214" = 0.105" I I I 11
_+/-_
I I- -T Penetration31 Ind. #2 '
- a= 0.177"*1 =0.157" 0.2 I
...............-------- ---------- -------------.... -'-..---- --- - - -. -- Penetration52 1nd.#3In -- _
- -- -- a= 0.132' i = 0.209" -
0.1
-. - - - -- .-- -.. ---.. .--, -- ,- - . ---. --. -. --- --- -- Penetration31 Ind. #1 ---
. .. .. .. .- a = 0.122" 1 = 0.15 7" 0
0.2 0.25 0.3 0.35 OA 0.45 0.5 Flaw Depth to Flaw Length Ratio (a/i)
Figure 2-3 Maximum Allowable Initial Circumferential Flaw Sizes for Repaired Penetration Nozzles Page 15 of 16
Document Control Desk Attachment 3 CR-12-04775 Westinghouse Non-Proprietary Class 3 RC-12-0170 Page 17 of 17 0.80 0.75 0.70 I 0.65 T: - ..... -: I~"! 1 :: : : : : : : : : :- .....
0.60 a'
0.55 [ : I- -I-* + ', ... .... ; ',.. 4 0.4I *JInitiala = .4 aaf0.2 -'0.2 I--
0.50 0
" 0.45
~~~~~~~~-
- 1 --+- ,+ , +r -+ ---+
-.---- p- T+ -r-*- -. - - i . - --- t - t -,---.-* --. -+
- .-- . -+
-- .- ,+ l -+ = --
0.40 +. . . . . +:i + : i . . .. ... . .. . . . . . . . . . . . . . . . . .-- -
+---+
-*- -+- -- :---- :----
0.35 .................. -:::::::::::
4:+,
-+ ,, - +
0.30 0 5 10 15 20 25 30 35 40 45 50 Time (years)
Figure 2-4 Fatigue Crack Growth For Hypothetical Bounding Axial and Circumferential Flaws Page 16 of 16