ML22332A455
| ML22332A455 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 11/10/2022 |
| From: | Electric Power Research Institute |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML22332A448 | List: |
| References | |
| RS-22-091, BWRVIP 2022-079 BWRVIP-135, Rev 4 | |
| Download: ML22332A455 (1) | |
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ATTACHMENT 7 BWRVIP-135, Revision 4: BWR Vessel Internals Project Integrated Surveillance Program (ISP) Data Source Book and Plant Evaluations (Non-Proprietary Version)
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2021 TECHNICAL REPORT BWRVIP-135, Revision 4: BWR Vessel and Internals Project Integrated Surveillance Program (ISP) Data Source Book and Plant Evaluations BWRVIP 2022-079, Attachment 1
Plant-Specific Evaluations 2-36 LaSalle 1 Representative Surveillance Materials The ISP Representative Surveillance Materials for the LaSalle 1 vessel target weld and plates are shown in the following table.
Table 2-52 Target Vessel Materials and ISP Representative Materials for LaSalle 1 Target Vessel Materials ISP Representative Materials Weld 1P3571 1P3571 Plate C5978-2 C6345-1 Summary of Available Surveillance Data: Plate The representative plate material C6345-1 is contained in the following ISP capsules:
LaSalle 1 Capsules Specific surveillance data related to plate heat C6345-1 are summarized in Appendix A-7. Two capsules containing this plate heat have been tested. The Charpy V-notch surveillance results are as follows:
Table 2-53 T30 Shift Results for Plate Heat C6345-1 Capsule Cu (wt%)
Ni (wt%)
Fluence (1017 n/cm2, E > 1 MeV)
T30 (°F)
LaSalle 1 300° 0.14 0.54 1.14 28.2 LaSalle 1 120° 3.66 32.7 The results given in Appendix A-7 show a fitted chemistry factor (CF) of (( (E))), as compared to a value of 97.3°F from the chemistry tables in Reg. Guide 1.99, Rev. 2. The maximum scatter in the fitted data is within the 1-sigma value of 17°F for plates as given in Reg. Guide 1.99, Rev. 2.
Conclusions and Recommendations Because the representative plate material is not the same heat number as the target plate in the LaSalle 1 vessel, the utility should use the chemistry factor from the Reg. Guide 1.99, Rev. 2 tables (Regulatory Position 1.1) to determine the projected ART value for the target vessel plate.
However, surveillance plate heat C6345-1 is a plate heat in the LaSalle 1 vessel beltline; therefore, the surveillance data reported in Appendix A-7 should be considered in the evaluation of that vessel plate. Because there are two irradiated data sets for this plate that fall within the 1-
Plant-Specific Evaluations 2-37 sigma scatter band, the ISP surveillance data should be used to revise the projected ART value for vessel plate heat C6345-1, with a reduced margin term (Regulatory Position 2.1).
Recommended guidelines for evaluation of ISP surveillance data are provided in Section 3 of this Data Source Book.
Summary of Available Surveillance Data: Weld The representative weld material 1P3571 is contained in the following ISP capsules:
LaSalle 1 Capsules Specific surveillance data related to weld heat 1P3571 are presented in Appendix B-8, and the results are summarized below. Two capsules containing weld heat 1P3571 have been tested. The Charpy V-notch surveillance results are as follows:
Table 2-54 T30 Shift Results for Weld Heat 1P3571 Capsule Cu (wt%)
Ni (wt%)
Fluence (1017 n/cm2, E > 1 MeV)
T30 (°F)
LaSalle 1 300° 0.21 0.75 1.14 36.6 LaSalle 1 120° 3.66 100.5 The results given in Appendix B-8 show a fitted chemistry factor (CF) of (( (E))),
compared to a value of 188.75°F from the chemistry tables in Reg. Guide 1.99, Rev. 2. The maximum scatter in the fitted data is well within the 1-sigma value of 28°F for welds as given in Reg. Guide 1.99, Rev. 2.
Conclusions and Recommendations Because the representative weld material is the same heat number as the target weld in the LaSalle 1 vessel, and because there are two valid irradiated data sets for this weld, the ISP surveillance data in Appendix B-8 should be used to revise the projected ART value for the target vessel weld. Recommended guidelines for use of ISP surveillance data are provided in Section 3 of this Data Source Book.
Plant-Specific Evaluations 2-38 LaSalle 2 Representative Surveillance Materials The ISP Representative Surveillance Materials for the LaSalle 2 vessel target weld and plates are shown in the following table.
Table 2-55 Target Vessel Materials and ISP Representative Materials for LaSalle 2 Target Vessel Materials ISP Representative Materials Weld 3P4966 402K9171, 411L3071 Plate C9404-2 C3054-2 Summary of Available Surveillance Data: Plate The representative plate material C3054-2 is contained in the following ISP capsules:
River Bend Capsules Specific surveillance data related to plate heat C3054-2 are summarized in Appendix A-11. One capsule containing this plate heat has been tested. The Charpy V-notch surveillance results are as follows:
Table 2-56 T30 Shift Results for Plate Heat C3054-2 Capsule Cu (wt%)
Ni (wt%)
Fluence (1017 n/cm2, E > 1 MeV)
T30 (°F)
River Bend 183° 0.08 0.67 11.6 44.0 No surveillance-based chemistry factor will be available until a second capsule is tested (see reference [1] for capsule test schedule).
Conclusions and Recommendations Because the representative plate material is not the same heat number as the target plate in the LaSalle 2 vessel, the utility should use the chemistry factor from the Reg. Guide 1.99, Rev. 2 tables (Regulatory Position 1.1) to determine the projected ART value for the target vessel plate.
Recommended guidelines for evaluation of ISP surveillance data are provided in Section 3 of this Data Source Book.
Plant-Specific Evaluations 2-39 Summary of Available Surveillance Data: Weld The representative weld material 402K9171, 411L3071 is contained in the following ISP capsules:
Susquehanna 1 Capsules Specific surveillance data related to weld heat 402K9171, 411L3071 are presented in Appendix B-14, and the results are summarized below. Two capsules containing weld heat 402K9171, 411L3071 have been tested. The Charpy V-notch surveillance results are as follows:
Table 2-57 T30 Shift Results for Weld Heat 402K9171, 411L3071 Capsule Cu (wt%)
Ni (wt%)
Fluence (1017 n/cm2, E > 1 MeV)
T30 (°F)
Susquehanna 1 30° 0.02 0.95 1.64 20.4 Susquehanna 1 120° 5.75 42.9 The results given in Appendix B-14 show a fitted chemistry factor (CF) of (( (E))), as compared to a value of 27.0°F from the chemistry tables in Reg. Guide 1.99, Rev. 2. The maximum scatter in the fitted data is (( (E))), which is well within the 1-sigma value of 28°F for welds as given in Reg. Guide 1.99, Rev. 2.
Conclusions and Recommendations Because the representative weld material is not the same heat number as the target weld in the LaSalle 2 vessel, the utility should use the chemistry factor from the Reg. Guide 1.99, Rev. 2 tables to determine the projected ART value for the target vessel weld. Recommended guidelines for evaluation of ISP surveillance data are provided in Section 3 of this Data Source Book.
ISP Plate Heat Evaluations A-107 A-7 Plate Heat: C6345-1 Summary of Available Charpy V-Notch Test Data The available Charpy V-notch test data sets for plate heat C6345-1 are listed in Table A-7-1. The source documents for the data are provided, and the capsule designations and fluence values are also provided for irradiated data sets.
Table A-7-1 ISP Capsules Containing Plate Heat C6345-1 Capsule Fluence (E> 1 MeV, 1017 n/cm2)
Reference Unirradiated Baseline Data Reference A-7-1 and A-7-2 LaSalle 1 300° 1.14 Reference A-7-9 LaSalle 1 120° 3.66 Reference A-7-9 The CVN test data for each set taken from the references noted above are presented in Tables A-7-7 through A-7-9. The BWRVIP ISP uses the hyperbolic tangent (tanh) function as a statistical curve-fit tool to model the transition temperature toughness data. Tanh curve plots for each Charpy energy data set have been generated using CVGRAPH, Version 5 [A-7-3] and the plots are provided in Figures A-7-1 through A-7-3.
Best Estimate Chemistry Table A-7-2 details the best estimate average chemistry values for plate heat C6345-1 surveillance material. Chemical compositions are presented in weight percent. If there are multiple measurements on a single specimen, those are first averaged to yield a single value for that specimen, and then the different specimens are averaged to determine the best estimate.
ISP Plate Heat Evaluations A-108 Table A-7-2 Best Estimate Chemistry of Available Data Sets for Plate Heat C6345-1 Cu (wt%)
Ni (wt%)
P (wt%)
S (wt%)
Si (wt%)
Specimen ID Source 0.14 0.56 0.015 B-417 Reference A-7-2 0.14 0.47 B-417 Reference A-7-1 0.14 0.515 0.015 Average B-417 0.12 0.49 0.015 B-433 Reference A-7-2 0.14 0.57 B-433 Reference A-7-1 0.13 0.53 0.015 Average B-433 0.11 0.50 0.016 B-435 Reference A-7-2 0.18 0.60 B-435 Reference A-7-1 0.145 0.55 0.016 Average B-435 0.15 0.56 B-411 Reference A-7-2 0.13 0.51 B-4J1 Reference A-7-2 0.15 0.57 B-436 Reference A-7-2 0.15 0.57 B-437 Reference A-7-2 0.13 0.50 B-4J5 Reference A-7-2 0.13 0.50 B-4JC Reference A-7-2 0.14 0.54 B-4JC Reference A-7-1 0.135 0.52 Average B-4JC 0.15 0.58 B-4J6 Reference A-7-2 0.15 0.56 B-4J6 Reference A-7-1 0.15 0.57 Average B-4J6 0.14 0.56 B-43B Reference A-7-2 0.13 0.51 B-413 Reference A-7-2 0.14 0.55 0.011 CE Reference A-7-2 0.14 0.54 0.014 Best Estimate Average Calculation of Chemistry Factor (CF):
The Chemistry Factor (CF) associated with the best estimate chemistry, as determined from U.S.
NRC Regulatory Guide 1.99, Revision 2 [A-7-4], Table 2 (base metal), is:
CF(C6345-1) = 97.3°F
ISP Plate Heat Evaluations A-109 Effects of Irradiation The radiation induced transition temperature shifts for heat C6345-1 are shown in Table A-7-3.
The T30 [30 ft-lb Transition Temperature], T50 [50 ft-lb Transition Temperature], and T35mil
[35 mil Lateral Expansion Temperature] index temperatures have been determined for each Charpy data set, and each irradiated set is compared to the baseline (unirradiated) index temperatures. The change in Upper Shelf Energy (USE) is also shown. The unirradiated and irradiated values are taken from the CVGRAPH fits presented at the back of this sub-appendix (only CVN energy fits are presented).
Comparison of Actual vs. Predicted Embrittlement A predicted shift in the 30 ft-lb transition temperature (T30) is calculated for each irradiated data set using the Reg. Guide 1.99, Rev. 2, Regulatory Position 1.1 method. Table A-7-4 compares the predicted shift with the measured T30 (°F) taken from Table A-7-3.
Comparison of Actual vs. Predicted Decrease in USE Table A-7-5 compares the actual percent decrease in upper shelf energy (USE) to the predicted decrease. The predicted decrease is estimated from Reg. Guide 1.99, Rev. 2, Figure 2; the measured percent decrease is calculated from the values presented in Table A-7-3.
ISP Plate Heat Evaluations A-110 Table A-7-3 Effect of Irradiation (E>1.0 MeV) on the Notch Toughness Properties of Plate Heat C6345-1 Material Identity Capsule ID T30, 30 ft-lb Transition Temperature T50, 50 ft-lb Transition Temperature T35mil, 35 mil Lateral Expansion Temperature CVN Upper Shelf Energy (USE)
Unirrad
(°F)
Irrad
(°F)
T30
(°F)
Unirrad
(°F)
Irrad
(°F)
T50
(°F)
Unirrad
(°F)
Irrad
(°F)
T35mil
(°F)
Unirrad (ft-lb)
Irrad (ft-lb)
Change (ft-lb)
LS1 C6345-1 300°
-37.0
-8.8 28.2
-15.7 20.2 35.9
-17.6 4.7 22.3 152.5 140.8
-11.7 120°
-37.0
-4.3 32.7
-15.7 29.6 45.3
-17.6 9.5 27.1 152.5 157.4 4.9 Table A-7-4 Comparison of Actual Versus Predicted Embrittlement for Plate Heat C6345-1 Capsule Identity Material Fluence (x1017 n/cm2)
Measured Shift1
°F RG 1.99 Rev. 2 Predicted Shift2
°F RG 1.99 Rev. 2 Predicted Shift+Margin2, 3
°F LS1 300° Plate Heat C6345-1 in LaSalle 1 1.14 28.2 11.7 23.3 LS1 120° 3.66 32.7 24.0 47.9 Notes:
- 1. See Table A-7-3, T30.
- 2. Predicted shift = CF FF, where CF is a Chemistry Factor taken from tables from Reg. Guide 1.99, Rev. 2, based on each materials Cu/Ni content, and FF is Fluence Factor, f0.28-0.10 log f, where f = fluence (1019 n/cm2, E > 1.0 MeV).
- 3. Margin = 2(i 2 +
2), where i = the standard deviation on initial RTNDT (which is taken to be 0ºF), and is the standard deviation on RTNDT (28ºF for welds and 17ºF for base materials, except that need not exceed 0.50 times the mean value of RTNDT). Thus, margin is defined as 34°F for plate materials and 56°F for weld materials, or margin equals shift (whichever is less), per Reg. Guide 1.99, Rev. 2.
ISP Plate Heat Evaluations A-111 Table A-7-5 Comparison of Actual Versus Predicted Percent Decrease in Upper Shelf Energy (USE) for Plate Heat C6345-1 Capsule Identity Material Fluence (x1017 n/cm2)
Cu Content (wt%)
Measured Decrease in USE1
(%)
RG 1.99 Rev. 2 Predicted Decrease in USE2 (%)
LS1 300° Plate Heat C6345-1 in LaSalle 1 1.14 0.14 7.7 8.0 LS1 120° 3.66
--3 10.5 Notes:
- 1. See Table A-7-3, (Change in USE)/(Unirradiated USE).
- 2. Calculated using equations in Regulatory Guide 1.162 [A-7-5] that accurately model the Charpy upper shelf energy decrease curves in Reg. Guide 1.99, Revision 2.
- 3. Value less than zero.
ISP Plate Heat Evaluations A-112 Credibility of Surveillance Data The credibility of the surveillance data is determined according to the guidance of Reg. Guide 1.99, Rev. 2 and 10 CFR 50.61, as supplemented by the NRC staff [A-7-6].
The following evaluation is based on the available surveillance data for irradiated plate heat C6345-1. The applicability of this evaluation to a particular BWR plant must be confirmed on a plant-by-plant basis to verify there are no plant-specific exceptions to the following evaluation.
Per Reg. Guide 1.99, Rev. 2 and 10 CFR 50.61, there are 5 criteria for the credibility assessment.
Criterion 1: Materials in the capsules should be those judged most likely to be controlling with regard to radiation embrittlement.
In order to satisfy this criterion, the representative surveillance material heat number must match the material in the vessel.
Criterion 2: Scatter in the plots of Charpy energy versus temperature for the irradiated and unirradiated conditions should be small enough to permit the determination of the 30 ft-lb temperature and upper shelf energy unambiguously.
Plots of Charpy energy versus temperature for the unirradiated and irradiated condition are presented in this sub-appendix. Based on engineering judgment, the scatter in these plots is small enough to permit the determination of the 30 ft-lb temperature and the upper shelf energy. Hence, this criterion is met.
Criterion 3: When there are two or more sets of surveillance data from one reactor, the scatter of RTNDT values about a best-fit line drawn as described in Regulatory Position 2.1 normally should be less than 17°F for plates. Even if the fluence range is large (two or more orders of magnitude), the scatter should not exceed twice that value. Even if the data fail this criterion for use in shift calculations, they may be credible for determining decrease in upper shelf energy if the upper shelf can be clearly determined, following the definition given in ASTM E185-82
[A-7-7].
For plate material C6345-1, there are 2 surveillance capsule data sets currently available.
The functional form of the least squares fit method as described in Regulatory Position 2.1 is utilized to determine a best-fit line for this data and to determine if the scatter of these RTNDT values about this line is less than 17°F for plates. Figure A-7-4 presents the best-fit line as described in Regulatory Position 2.1 utilizing the shift prediction routine from CVGRAPH, Version 5.0.2.
The scatter of RTNDT values about the functional form of the best-fit line drawn as described in Regulatory Position 2.1 is presented in Table A-7-6.
ISP Plate Heat Evaluations A-113 Table A-7-6 Best Fit Evaluation for Surveillance Plate Heat C6345-1 Material Fitted CF
(°F)
Capsule FF Measured RTNDT (30 ft-lb)1
(°F)
Best Fit RTNDT2
(°F)
Scatter of RTNDT3
(°F)
<17°F (Base Metal)
<28°F (Weld metal)
C6345-1
((
(E)))
300 0.120 28.2
((
(E)))
((
(E)))
Yes 120 0.246 32.7
((
(E)))
((
(E)))
Yes 1.
See Table A-7-3, T30.
2.
Best Fit shift = Fitted CF FF, where Fitted CF is taken from Figure A-7-4 and FF is Fluence Factor, f0.28-0.10 log f, where f = fluence (1019 n/cm2, E > 1.0 MeV).
3.
Scatter = Measured RTNDT - Best Fit RTNDT Table A-7-6 shows that the scatter is within acceptable range for credible surveillance data. Therefore, plate heat C6345-1 meets this criterion.
Criterion 4: The irradiation temperature of the Charpy specimens in the capsule should match the vessel wall temperature at the cladding/base metal interface within + / - 25°F.
BWRVIP-78 [A-7-8] established the similarity of BWR plant environments in the BWR fleet. The annulus between the wall and the core shroud in the region of the surveillance capsules contains a mix of water returning from the core and feedwater. Depending on feedwater temperature, this annulus region is between 525°F and 535°F. This location of specimens with respect to the reactor vessel beltline is designed so that the reactor vessel wall and the specimens experience equivalent operating conditions such that the temperature will not differ by more than 25°F. Any plant-specific exceptions to this generic analysis should be evaluated.
Criterion 5: The surveillance data for the correlation monitor material in the capsule should fall within the scatter band of the database for that material.
Few ISP capsules contain correlation monitor material. Generally, this criterion is not applicable.
For plate heat C6345-1, these criteria are satisfied (or not applicable). The surveillance data are nominally credible because the scatter criterion is met. Prior to application of the data, a plant should verify that no plant-specific exceptions to these criteria exist.
ISP Plate Heat Evaluations A-114 Table A-7-7 Unirradiated Charpy V-Notch Results for Surveillance Plate C6345-1 (LT)
Spec ID Temp (°F) CVN (ft-lb)
LE (mils)
%Shear 1
-80 8.0 4.0 0
2
-80 6.0 4.0 0
3
-40 29.0 21.0 5
4
-40 15.0 13.0 0
5
-40 23.0 16.0 1
6 10 109.0 76.0 50 7
10 88.0 58.0 35 8
10 77.0 56.0 35 9
40 103.0 68.0 45 10 40 96.0 65.0 40 11 40 122.0 77.0 60 12 110 147.0 84.0 100 13 110 147.0 82.0 100 14 160 151.0 87.0 100 15 160 165.0 94.0 100 Table A-7-8 Charpy V-Notch Results for C6345-1 (LT) in LS1 300° Capsule Spec ID Temp (°F) CVN (ft-lb)
LE (mils)
%Shear 411 0
17.5 21.5 15 413 40 90.5 75.5 38 417
-40 18.5 13.5 8
433
-20 19.0 15.5 14 435
-80 6.0 8.0 4
436 300 138.5 95.0 100 437 80 98.0 78.0 58 43B 30 69.0 61.0 28 4J1 120 129.5 82.0 81 4J5 10 50.0 42.0 25 4J6 200 140.0 84.0 100 4JC 60 58.0 51.0 35
ISP Plate Heat Evaluations A-115 Table A-7-9 Charpy V-Notch Results for C6345-1 (LT) in LS1 120° Capsule Spec ID Temp (°F) CVN (ft-lb)
LE (mils)
%Shear 43A
-115.6 3.62 6
2.7 43J
-21.6 16.44 14 12.7 43C 2.5 55.55 48.5 28.3 434 27.5 71.86 56 37.6 43M 40.6 20.89 21 32.8 43K 68.5 96.81 80.5 63.2 4JA 85.6 47.8 42 41.6 43T 100 134.09 79.5 76.6 43D 124 128.45 87.5 91.8 415 204.3 152.64 96 100 412 269.4 161.09 95 100 43Y 367.9 158.46 84.5 100
ISP Plate Heat Evaluations A-116 Tanh Curve Fits of CVN Test Data for Plate Heat C6345-1 Figure A-7-1 Charpy Energy Data for Plate C6345-1 (LT) Unirradiated
ISP Plate Heat Evaluations A-117 Figure A-7-1 (continued)
Charpy Energy Data for Plate C6345-1 (LT) Unirradiated
ISP Plate Heat Evaluations A-118 Figure A-7-2 Charpy Energy Data for Plate C6345-1 (LT) in LS1 300° Capsule
ISP Plate Heat Evaluations A-119 Figure A-7-2 (continued)
Charpy Energy Data for Plate C6345-1 (LT) in LS1 300° Capsule
ISP Plate Heat Evaluations A-120 Figure A-7-3 Charpy Energy Data for Plate C6345-1 (LT) in LS1 120° Capsule
ISP Plate Heat Evaluations A-121 Figure A-7-3 (continued)
Charpy Energy Data for Plate C6345-1 (LT) in LS1 120° Capsule
ISP Plate Heat Evaluations A-122
((
(E)))
Figure A-7-4 Fitted Surveillance Results for LaSalle Unit 1 Plate Heat C6345-1
ISP Plate Heat Evaluations A-123 References A-7-1. Letter from Commonwealth Edison Company to USNRC, LaSalle County Nuclear Power Station Units 1 and 2 Response to October 25, 1995 NRC Request for Additional Information on LaSalle Unit 1 RPV Surveillance Material Testing and Analysis, Reactor Vessel Material Surveillance Program - Appendix H, NRC Docket Nos. 50-373 and 50-374, Commonwealth Edison Company, dated December 20, 1995.
A-7-2. LaSalle Unit 1 RPV Surveillance Materials Testing and Analysis, T.A. Caine, R.G.
Carey, and B.J. Branlund, GE Nuclear Energy, GE-NE-523-A166-1294, Revision 1, June 1995.
A-7-3. CVGRAPH, Hyperbolic Tangent Curve Fitting Program, Developed by ATI Consulting, Version 5.0.2, Revision 1, 3/26/02.
A-7-4. Radiation Embrittlement of Reactor Vessel Materials, USNRC Regulatory Guide 1.99, Revision 2, May 1988.
A-7-5. Format and Content of Report for Thermal Annealing of Reactor Pressure Vessels, USNRC Regulatory Guide 1.162, February 1996.
A-7-6. K. Wichman, M. Mitchell, and A. Hiser, USNRC, Generic Letter 92-01 and RPV Integrity Workshop Handouts, NRC/Industry Workshop on RPV Integrity Issues, February 12, 1998.
A-7-7. ASTM E-185, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels, American Society for Testing and Materials, July 1982.
A-7-8. BWR Vessel and Internals Project: BWR Integrated Surveillance Program Plan (BWRVIP-78). EPRI, Palo Alto, CA and BWRVIP: 1999, TR-114228.
A-7-9. BWR Vessel and Internals Project, Testing and Evaluation of the LaSalle Unit 1 120° Surveillance Capsule (BWRVIP-250). EPRI, Palo Alto, CA: 2011. 1022850.
ISP Weld Heat Evaluations B-129 B-8 Weld Heat: 1P3571 Summary of Available Charpy V-Notch Test Data The available Charpy V-notch test data sets for weld heat 1P3571 are listed in Table B-8-1.
The source documents for the data are provided, and the capsule designations and fluence values are also provided for irradiated data sets.
Table B-8-1 ISP Capsules Containing Weld Heat 1P3571 Capsule Fluence (E> 1 MeV, 1017 n/cm2)
Reference Unirradiated Baseline Data Reference B-8-1 and B-8-2 LaSalle 300° 1.14 Reference B-8-9 LaSalle 120° 3.66 Reference B-8-9 The CVN test data for each set taken from the references noted above are presented in Tables B-8-7 through B-8-9. The BWRVIP ISP uses the hyperbolic tangent (tanh) function as a statistical curve-fit tool to model the transition temperature toughness data. Tanh curve plots for each data set have been generated using CVGRAPH, Version 5 [Reference B-8-3] and the plots are provided in Figures B-8-1 through B-8-3.
Best Estimate Chemistry Table B-8-2 details the best estimate average chemistry values for weld heat 1P3571 surveillance material. Chemical compositions are presented in weight percent. If there are multiple measurements on a single specimen, those are first averaged to yield a single value for that specimen, and then the different specimens are averaged to determine the best estimate.
ISP Weld Heat Evaluations B-130 Table B-8-2 Best Estimate Chemistry of Available Data Sets for Weld Heat 1P3571 Cu (wt%)
Ni (wt%)
P (wt%)
S (wt%)
Si (wt%)
Specimen ID Source 0.2 0.73 44U Reference B-8-2 0.22 0.73 44M Reference B-8-2 0.18 0.64 44M Reference B-8-1 0.20 0.685 Average 44M 0.2 0.74 4LD Reference B-8-2 0.2 0.75 0.017 443 Reference B-8-2 0.19 0.69 443 Reference B-8-1 0.195 0.72 0.017 Average 443 0.22 0.75 444 Reference B-8-2 0.2 0.76 0.016 44A Reference B-8-2 0.18 0.7 44A Reference B-8-1 0.19 0.73 0.016 Average 44A 0.22 0.79 447 Reference B-8-2 0.21 0.8 45K Reference B-8-2 0.21 0.8 45M Reference B-8-2 0.22 0.8 45D Reference B-8-2 0.23 0.82 0.014 45E Reference B-8-2 0.18 0.69 45E Reference B-8-1 0.18 0.64 45E Reference B-8-1 0.197 0.717 0.014 Average 45E 0.22 0.83 44F Reference B-8-2 0.19 0.71 44F Reference B-8-1 0.205 0.77 Average 44F 0.21 0.78 0.015 CE Reference B-8-2 0.21 0.75 0.016 Best Estimate Average Calculation of Chemistry Factor (CF):
The Chemistry Factor (CF) associated with the best estimate chemistry, as determined Reg.
Guide 1.99, Revision 2 [Reference B-8-4], Table 1 (weld metal), is:
CF(1P3571) = 188.75 °F
ISP Weld Heat Evaluations B-131 Effects of Irradiation The radiation induced transition temperature shifts for heat 1P3571 are shown in Table B-8-3.
The T30 [30 ft-lb Transition Temperature], T50 [50 ft-lb Transition Temperature], and T35mil
[35 mil Lateral Expansion Temperature] index temperatures have been determined for each Charpy data set, and each irradiated set is compared to the baseline (unirradiated) index temperatures. The change in Upper Shelf Energy (USE) is also shown. The unirradiated and irradiated values are taken from the CVGRAPH fits presented at the back of this sub-appendix (only CVN energy fits are presented).
Comparison of Actual vs. Predicted Embrittlement A predicted shift in the 30 ft-lb transition temperature (T30) is calculated for each irradiated data set using the Reg. Guide 1.99, Rev. 2, Regulatory Position 1.1 method. Table B-8-4 compares the predicted shift with the measured T30 (°F) taken from Table B-8-3.
Comparison of Actual vs. Predicted Decrease in USE Table B-8-5 compares the actual percent decrease in upper shelf energy (USE) to the predicted decrease. The predicted decrease is estimated from Reg. Guide 1.99, Rev. 2, Figure 2; the measured percent decrease is calculated from the values presented in Table B-8-3.
ISP Weld Heat Evaluations B-132 Table B-8-3 Effect of Irradiation (E>1.0 MeV) on the Notch Toughness Properties of Weld Heat 1P3571 Material Identity Capsule ID T30, 30 ft-lb Transition Temperature T50, 50 ft-lb Transition Temperature T35mil, 35 mil Lateral Expansion Temperature CVN Upper Shelf Energy (USE)
Unirrad
(°F)
Irrad
(°F)
T30
(°F)
Unirrad
(°F)
Irrad
(°F)
T50
(°F)
Unirrad
(°F)
Irrad
(°F)
T35mil
(°F)
Unirrad (ft-lb)
Irrad (ft-lb)
Change (ft-lb)
LS1 1P3571 300°
-50.6
-14.0 36.6
-7.6 31.4 39.0
-37.3 2.5 39.8 114.5 107.7
-6.8 120°
-50.6 49.9 100.5
-7.6 87.3 94.9
-37.3 68.7 106.0 114.5 97.7
-16.8 Table B-8-4 Comparison of Actual Versus Predicted Embrittlement for Weld Heat 1P3571 Capsule Identity Material Fluence (x1017 n/cm2)
Measured Shift 1
°F RG 1.99 Rev. 2 Predicted Shift 2
°F RG 1.99 Rev. 2 Predicted Shift+Margin 2, 3
°F LS1 300° Weld Heat 1P3571 in LaSalle 1 1.14 36.6 22.6 45.2 LS1 120° 3.66 100.5 46.5 93.0 Notes:
1.
See Table B-8-3, T30.
2.
Predicted shift = CF x FF, where CF is a Chemistry Factor taken from tables from Reg. Guide 1.99, Rev. 2, based on each materials Cu/Ni content, and FF is Fluence Factor, f 0.28-0.10 log f, where f = fluence (1019 n/cm2, E > 1.0 MeV).
3.
Margin = 2 (i2 + 2), where i = the standard deviation on initial RTNDT (which is taken to be 0°F), and is the standard deviation on RTNDT (28°F for welds and 17°F for base materials, except that need not exceed 0.50 times the mean value of RTNDT). Thus, margin is defined as 34°F for plate materials and 56°F for weld materials, or margin equals shift (whichever is less), per Reg. Guide 1.99, Rev. 2.
ISP Weld Heat Evaluations B-133 Table B-8-5 Comparison of Actual Versus Predicted Percent Decrease in Upper Shelf Energy (USE) for Weld Heat 1P3571 Capsule Identity Material Fluence (x1017 n/cm2)
Cu Content (wt%)
Measured Decrease in USE 1 (%)
RG 1.99 Rev. 2 Predicted Decrease in USE 2
(%)
LS1 300° Weld Heat 1P3571 in LaSalle 1 1.14 0.21 5.9 12.1 LS1 120° 3.66 14.7 16.0 Notes:
1.
See Table B-8-3, (Change in USE)/(Unirradiated USE).
2.
Calculated using equations in Reg. Guide 1.162 [B-8-5] that accurately model the Charpy upper shelf energy decrease curves in Reg. Guide 1.99, Revision 2.
ISP Weld Heat Evaluations B-134 Credibility of Surveillance Data The credibility of the surveillance data is determined according to the guidance of Reg. Guide 1.99, Rev. 2 and 10 CFR 50.61, as supplemented by the NRC staff [Ref. B-8-6]. The following evaluation is based on the available surveillance data for irradiated weld heat 1P3571. The applicability of this evaluation to a particular BWR plant must be confirmed on a plant-by-plant basis to verify there are no plant-specific exceptions to the following evaluation.
Per Reg. Guide 1.99, Revision 2 and 10 CFR 50.61, there are 5 criteria for the credibility assessment.
Criterion 1: Materials in the capsules should be those judged most likely to be controlling with regard to radiation embrittlement.
In order to satisfy this criterion, the representative surveillance material heat number must match the material in the vessel.
Criterion 2: Scatter in the plots of Charpy energy versus temperature for the irradiated and unirradiated conditions should be small enough to permit the determination of the 30 ft-lb temperature and upper shelf energy unambiguously.
Plots of Charpy energy versus temperature for the unirradiated and irradiated condition are presented in this sub-appendix. Based on engineering judgment, the scatter in these plots is small enough to permit the determination of the 30 ft-lb temperature and the upper shelf energy. Hence, this criterion is met.
Criterion 3: When there are two or more sets of surveillance data from one reactor, the scatter of RTNDT values about a best-fit line drawn as described in Regulatory Position 2.1 normally should be less than 28°F for welds. Even if the fluence range is large (two or more orders of magnitude), the scatter should not exceed twice that value. Even if the data fail this criterion for use in shift calculations, they may be credible for determining decrease in upper shelf energy if the upper shelf can be clearly determined, following the definition given in ASTM E185-82
[B-8-7].
For weld heat 1P3571, there are 2 surveillance capsule data sets currently available. The functional form of the least squares fit method as described in Regulatory Position 2.1 is utilized to determine a best-fit line for this data and to determine if the scatter of these RTNDT values about this line is less than 28°F for welds. Figure B-8-4 presents the best-fit line as described in Regulatory Position 2.1 utilizing the shift prediction routine from CVGRAPH, Version 5.0.2.
The scatter of RTNDT values about the functional form of the best-fit line drawn as described in Regulatory Position 2.1 is presented in Table B-8-6.
ISP Weld Heat Evaluations B-135 Table B-8-6 Best Fit Evaluation for Surveillance Weld Heat 1P3571 Material Fitted CF
(°F)
Capsule FF Measured RTNDT (30 ft-lb)1
(°F)
Best Fit RTNDT2
(°F)
Scatter of RTNDT3
(°F)
<17°F (Base Metal)
<28°F (Weld metal) 1P3571
((
(E)))
300 0.120 36.6
((
(E)))
((
(E)))
Yes 120 0.246 100.5
((
(E)))
((
(E)))
Yes 1.
See Table B-8-3, T30.
2.
Best Fit shift = Fitted CF x FF, where Fitted CF is taken from Figure B-8-4 and FF is Fluence Factor, f
0.28-0.10 log f, where f = fluence (1019 n/cm2, E > 1.0 MeV).
3.
Scatter = Measured RTNDT - Best Fit RTNDT Table B-8-6 shows that the scatter is within acceptable range for credible surveillance data. Therefore, weld heat 1P3571 meets this criterion.
Criterion 4: The irradiation temperature of the Charpy specimens in the capsule should match the vessel wall temperature at the cladding/base metal interface within + / - 25°F.
BWRVIP-78 [B-8-8] established the similarity of BWR plant environments in the BWR fleet. The annulus between the wall and the core shroud in the region of the surveillance capsules contains a mix of water returning from the core and feedwater. Depending on feedwater temperature, this annulus region is between 525°F and 535°F. This location of specimens with respect to the reactor vessel beltline is designed so that the reactor vessel wall and the specimens experience equivalent operating conditions such that the temperature will not differ by more than 25°F. Any plant-specific exceptions to this generic analysis should be evaluated.
Criterion 5: The surveillance data for the correlation monitor material in the capsule should fall within the scatter band of the database for that material.
Few ISP capsules contain correlation monitor material. Generally, this criterion is not applicable.
For weld heat 1P3571, these criteria are satisfied (or not applicable). The surveillance data are nominally credible because the scatter criterion is met. Prior to application of the data, a plant should verify that no plant-specific exceptions to these criteria exist.
ISP Weld Heat Evaluations B-136 Table B-8-7 Unirradiated Charpy V-Notch Results for Surveillance Weld 1P3571 Spec ID Temp (°F)
CVN (ft-lb)
Len (mils)
%Shear 1
-320 2.2 2
0 2
-150 3.4 3
1 3
-100 7.3 8
10 4
-75 14.9 14 10 5
-50 28 30 30 6
-35 32.9 39 30 7
-20 45.5 43 40 8
0 45.2 41 40 9
10 50.4 49 50 10 10 52.6 53 50 11 10 42.7 43 40 12 30 78.9 67 60 13 30 59.2 46 50 14 30 59.8 50 50 15 71 90.3 83 90 16 150 105 90 99 17 250 106.8 88 99 18 350 109.4 92 99 22
-200 3
3 3
23
-200 5.5 6
5 24
-200 7
6 5
25
-150 36 34 34 26
-150 15 16 17 27
-150 32 31 27 28
-100 11.5 13 9
ISP Weld Heat Evaluations B-137 Table B-8-7 (continued)
Unirradiated Charpy V-Notch Results for Surveillance Weld 1P3571 Spec ID Temp (°F)
CVN (ft-lb)
Len (mils)
%Shear 29
-100 13 12 13 30
-100 20 18 14 31
-40 40 37 38 32
-40 41 37 43 33
-40 29.5 29 37 34 10 66 60 55 35 10 67 62 64 36 10 55.5 50 43 37 40 79 71 81 38 40 83 72 81 39 40 45 73 66 40 75 97.5 82 90 41 75 92 77 89 42 75 102.5 87 96 43 210 125 98 100 44 210 126.5 98 100 45 210 126 99 100 19*
10 79 20*
10 68 21*
10 64
- Lateral Expansion and %Shear not available for these data points.
Table B-8-8 Charpy V-Notch Results for 1P3571 in LS1 300° Capsule Spec ID Temp (°F)
CVN (ft-lb)
LE (mils)
%Shear 443
-40 19.5 19.5 20 444 40 35 38 39 447 80 65.5 62 45 44A
-80 5.5 9.5 9
44F 120 89.5 71 93 44M 300 107 84 100 44U 0
41 39 32 45D 200 101 84 100 45E
-10 40 36 31 45K 20 48 37 43 45M 60 74 65 75 4LD 100 86.5 89 83
ISP Weld Heat Evaluations B-138 Table B-8-9 Charpy V-Notch Results for 1P3571 in LS1 120° Capsule Spec ID Temp (°F)
CVN (ft-lb)
LE (mils)
%Shear 44J
-138.6 2.46 0.5 2.5 45B
-50.8 9.17 8
10.7 45A
-14.9 25.3 20 17.9 441 38.8 20.57 18 28.7 45J 53.1 34.13 27.5 29.6 4LJ 68.3 31.28 27 28.6 45L 99.9 56.33 50.5 65.7 44Y 124.2 74.12 72 82.3 45T 148.6 79.58 69 87.8 44D 196.7 94.82 78 98.4 44C 270.3 106.09 75 100 45Y 348.8 92.06 72 100
ISP Weld Heat Evaluations B-139 Tanh Curve Fits of CVN Test Data for Weld Heat 1P3571 Figure B-8-1 Charpy Energy Data for Weld 1P3571 Unirradiated
ISP Weld Heat Evaluations B-140 Figure B-8-1 (continued)
Charpy Energy Data for Weld 1P3571 Unirradiated
ISP Weld Heat Evaluations B-141 Figure B-8-2 Charpy Energy Data for Weld 1P3571 in LS1 300° Capsule
ISP Weld Heat Evaluations B-142 Figure B-8-2 (continued)
Charpy Energy Data for Weld 1P3571 in LS1 300° Capsule
ISP Weld Heat Evaluations B-143 Figure B-8-3 Charpy Energy Data for Weld 1P3571 in LS1 120° Capsule
ISP Weld Heat Evaluations B-144 Figure B-8-3 (continued)
Charpy Energy Data for Weld 1P3571 in LS1 120° Capsule
ISP Weld Heat Evaluations B-145
((
(E)))
Figure B-8-4 Fitted Surveillance Results for LaSalle Unit 1 Weld Heat 1P3571
ISP Weld Heat Evaluations B-146 References B-8-1. Letter from Commonwealth Edison Company to USNRC, LaSalle County Nuclear Power Station Units 1 and 2 Response to October 25, 1995 NRC Request for Additional Information on LaSalle Unit 1 RPV Surveillance Material Testing and Analysis, Reactor Vessel Material Surveillance Program - Appendix H, NRC Docket Nos. 50-373 and 50-374, Commonwealth Edison Company, dated December 20, 1995.
B-8-2. LaSalle Unit 1 RPV Surveillance Materials Testing and Analysis, T.A. Caine, R.G.
Carey, and B.J. Branlund, GE Nuclear Energy, GE-NE-523-A166-1294, Revision 1, June 1995.
B-8-3. CVGRAPH, Hyperbolic Tangent Curve Fitting Program, Developed by ATI Consulting, Version 5.0.2, Revision 1, 3/26/02.
B-8-4. Radiation Embrittlement of Reactor Vessel Materials, USNRC Regulatory Guide 1.99, Revision 2, May 1988.
B-8-5 Format and Content of Report for Thermal Annealing of Reactor Pressure Vessels, USNRC Regulatory Guide 1.162, February 1996.
B-8-6. K. Wichman, M. Mitchell, and A. Hiser, USNRC, Generic Letter 92-01 and RPV Integrity Workshop Handouts, NRC/Industry Workshop on RPV Integrity Issues, February 12, 1998.
B-8-7. ASTM E-185, Standard Practice for Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels, American Society for Testing and Materials, July 1982.
B-8-8. BWR Vessel and Internals Project: BWR Integrated Surveillance Program Plan (BWRVIP-78). EPRI, Palo Alto, CA and BWRVIP: 1999, TR-114228.
B-8-9. BWR Vessel and Internals Project, Testing and Evaluation of the LaSalle Unit 1 120° Surveillance Capsule (BWRVIP-250NP). EPRI, Palo Alto, CA: 2011. 1022850.