ML18038A738

Upper Shelf Energy Uncertainty Analysis for Nine Mile Point Unit 1 Beltline Welds Final Rept

ML18038A738
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Site:	Nine Mile Point
Issue date:	03/17/1993
From:	NIAGARA MOHAWK POWER CORP.
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MPM-USE-393215, NUDOCS 9303260006
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NMPC Project 03-9425 MPM-USE-393215 FINAL REPORT.entitled UPPER SHELF ENERGY UNCERTAINTY ANALYSIS FOR I NINE MILE POINT UNIT I BELTLINE WELDS MPM Research dc Consuming l5 pt,+4 ii]j.r T H1$+4 WTt fh II 8SVNR7~AKK58 mxiuvr mmmm muavxcev March 17, 1993 9303260006 9303i9 PDR ADQCK 05000220 P PDR e'4 k ql I 0 I Table of Contents 1.0 Introduction

.......1.1 Weld Metal Description

..~~~~~~~~~~~~~~~~~~~4 2.0 Yield Strength Model Description.................................

9 2.1 Theoretical Basis.......9 2.2 Review of Earlier Application to NMP-1 Beltline Welds...........

10 3.0 3.2 3.3 3,4 3.5 Uncertainty Estimation........................

3.1 Database

Analysis 3.1.1 Analysis of Outliers 3.1.2 Summary.............,.........

USE Estimation Uncertainty

..............

Yield Strength Model Update..............

Application of Updated Model to NMP-1 Welds Tensile/USE Measurement Uncertainty

......3.5.1 Tensile Uncertainty Analysis...~3.5.2 USE Uncertainty

............'......

3.5.3 Summary.......................

16 16 17 18 19 19 20 20 20 21 22 4.0 Summary and Conclusions

................

44 5.0 References

....................

45 A l'$4,

1.0 Introduction

Nuclear reactor pressure vessel materials must be tested and evaluated to ensure that they are safe in terms of both brittle and ductile fracture under normal operation and during design basis transients.

With regard to ductile fracture protection, Appendix G to 10 CFR 50 prescribes a screening criterion of 50 ft-lbs.If any beltline materials are expected to exhibit Charpy Upper Shelf Energy (USE)(T-L orientation for plates)levels below 50 ft-lbs, then additional analyses must be performed to ensure continued safe operation.

The NMP-1 beltline materials were evaluated to determine whether any materials would fall below the 50 ft-Ib screening criterion.

The results of these evaluations are summarized in Reference[MA93a]and were presented in the response to NRC Generic Letter 92-01.As a result of these evaluations, NMPC concluded that none of the beltline welds would fall below the 50 ft-Ib screening criterion prior to end-of-license (EOL)and that an Appendix X analysis must be performed for beltline plates G-8-1 and G-307-4.The results of the Appendix X analysis for Service Level A and B loadings were reported in Reference[MA93a], and the results of the Service Level C and D loading analysis were reported in Reference[MA93b].Full Charpy curves for the NMP-1 beltline weld materials in the unirradiated condition are not available.

Therefore, the Reference[OD86]yield strength model (as described in Section 2.0)was used to estimate the unirradiated USE levels for the NMP-1 beltline welds.During a presentation to the NRC on September 30, 1992, concerning the low USE issue resolution, the NRC requested that NMPC accurately characterize the uncertainty in.the yield strength model to ensure that the level of conservatism used to calculate the unirradiated USE for the beltline welds is sufficient.

The NRC request was later formalized in the Reference[NRC92]letter.In response to the NRC's request, NMPC has prepared this report which accurately characterizes the yield strength model uncertainty.

Based on this analysis,-NMPC has concluded that the previously estimated USE values for the beltline welds are conservative and that none of the beltline welds will fall below the 50 ft-Ib screening criterion prior to EOL.1.1 Weld Metal Description The chemical composition and mechanical properties of the NMP-1 welds are reported in References

[ST84],[MA91], and[MA92a].Based on the Reference[ABB92]letter, NMPC now believes that only one wire heat/flux lot combination was used in welds 2-564-A/C.

The updated reactor vessel beltline weld information is given in Tables 1-1 through 1-3.Table 1-4 summarizes the surveillance weld Charpy data.

0 Weld Seam TABLE 1-1 REACTOR VESSEL BELTLINE WELD INFORMATION Number Location Weld Wire Type and Heat No.Weld Flux Type and Lot No.Detailed Weld Procedure 2-564 A/C 2-564 D/F 3-564 Surveillance Capsule Weld Lower-Intermediate Shell Longitudinal Lower Shell Longitudinal Seams Lower Intermediate to Lower Shell Girth All Three Capsules RACO 3/86054 E8018/HAD D E8018/JBG D RACO 3/86054 E8018/HAG D E8018/JBG D RACO 3/1248 E8018/DBDE E8018/IOG E RACO 3/W5214 Arcos B-5/4ES F N/A N/A Arcos B-5/4ESF N/A N/A Arcos B-5/4M2F N/A N/A Arcos B-5/SG13F SAA-33-A(3)

MA-33-A(7)

MA-33-A(7)

SAA-33-A(3)

MA-33-A(7)

MA-33-A(7)

SAA-33-A(3)

MA-33-A(7)

MA-33-A(7)

SAA-33-A(3)

References

[CE90]and[ABB92]

0 J Y i TABLE 1-2 NMP-1 Beltline and Surveillance Weld Best Estimate Chemistry IDENTIFICATION CHEMICAL COMPOSITION (WT.%)Weld Seam 2-564 A/C'eld Seam 2-564 D/F'eld Seam 3-564'URVEILLANCE WELD': Cu 0.22 0.22 0.22 0.18 Ni 0.2 0.2 0.2 0,07 0.015 0.020 0.015 0.020 0.015 0.020 0.022 0.013'Average of Battelle/Westinghouse data[MA91]'E recommendation

[CE90]

Table 1-3 NMP-1 Beltline Weld Tensile Data'Te Heat No.Flux Lot No.Yield Strength Ultimate Tensile Stren th si Elon ation%Reduction A RACO3 86054 RAC 03-1248 Surveillance Capsule Weld Unirradiated W5214 Surveillance Capsule Weld Irradiated'5214 4ESF 4M2F 5613F 5G13F-75/00 63,000 65,000 73,680 90,000 80,000 84,000 90,240 27.5 27.5 27.5 23.24 69.9 64.3 67.0 68.1'ata taken from[LE64],[ST84], and[CE90].The unirradiated material test records do not indicate the test temperature.

Therefore, RT is assumed.'00-degree capsule fluence=4.78 x 10" n/cm';RT properties

'n 2 inches"in 1inch

Table 1-4 Summary of Charpy Impact Properties for Irradiated Weld Metal.from the NMP-1 300-Degree Surveillance Capsule'aterial W5212/5613F E>1.0 MeV Fluence, n/cm'.78 x 10" 30 ft-lb Transition Temperature,'F 50 ft-lb Transition Temperature,'F 35-Mil Lateral Expansion Temperature,'F-22 Upper Shelf Energy, ft-lb 110'ata taken from[ST84]and[MA90]

0 t$I yf C<<S (l

2.0 YIeld

Strength Model Description

~~2.1 Theoretical Basis Odette et,al.[OD86]have reported empirical relationships between irradiation strengthening and embrittlement.

In particular, these researchers have observed a correlation between 30 ft-Ib indexed Charpy shift (ET,Q)and elevation in yield strength (do)(Figure 2-1), and between the fractional decrease in USE (f)and do(Figure 2-2), As discussed by Odette et.al., establishing correlations between Charpy parameters and microstructure-sensitive properties (such as yield strength)is of interest in gaining deeper understanding of radiation damage impacts on mechanical behavior.The correlations proposed in Reference[OD86]assume continuous hardening (haincreases continuously), which is consistent with microstructural data reported in the literature.

With regard to USE decreases, Odette et.al.state,"Details of the influence of irradiation on these processes (ductile fracture)are complex and not well understood...

we believe that the overall effect of irradiation on C(Charpy V-notch)upper shelf ductile fracture may be related primarily to reduced strain hardening and flow localization leading to lower ductility and to increased triaxial stress state in C-sized specimens due to strength increases." Recent work by Manahan[MA92b]on irradiation effects on upper shelf fracture trends and mechanisms produced results which are consistent with the Reference[OD86]observations, and this work points out that non-hardening mechanisms, such as element transport to grain boundaries and possibly to particle interfaces, may play a role in the ductile fracture process, If such mechanisms are indeed active, then it is not possible to entirely characterize the shelf drop using hardening models.Nevertheless, the strong empirical correlation between t and Ao reported by Odette et.ai.can be used to estimate the unirradiated USE provided t e uncertainty is adequately characterized.

Reference[OD86]proposed the following empirical correlation for plates and welds based on analysis of the LWR database: f=6.2 x 10'o, for 0<ho<5.8 ksi f 6 2 x 10 BGy+0 02 (6 895 6Gy%0)'ol Gy>5.8 ksi where, ho=increase in yield strength (ksi)(2-1)(2-2)Therefore, using this expression for f, it is possible to calculate the unirradiated USE provided irradiated USE and hodata are available.

0 I, 0[

2.2 Review

of Earlier Application to NMP-1 Beltllne Welds Full Charpy curves for the NMP-1 beltline welds were not measured at the time when the vessel was fabricated.

However, Charpy data at 10'F were measured by Combustion Engineering and these data are summarized in References

[MA90]and[MA91].An innovative methodology

[MA85a]was developed to determine the initial RT>>for cases where the data required by the ASME Code are not available.

This approach was applied to the NMP-1 beltline materials and the results are described in Reference[MA90]and were reported in Reference[MA92a].The methodology for RT>>, determination includes estimation of the unirradiated USE in cases where full Charpy curves are not available.

This method requires yield strength change and the upper shelf energy for the irradiated metal.For NMP-1, the surveillance weld data are available at a fast fluence of 4.78 x 10" n/cm'.The yield strength model described earlier was used to estimate the surveillance weld unirradiated USE using the irradiated USE as input.In particular, USE'=(t(2-3)where, f=fractional change in USE=AUSE USE'SE'unirradiated USE (ft-Ibs)USE'""=irradiated USE (ft-Ibs)AUSE=USE'-USE'"" (ft-Ibs)As described earlier, for her>5.8 ksi, Equation (2-2)should be used for calculation of"f".The irradiated USE was measured at 7.98 EFPY and found to be 110 ft-lbs.Using the measured yield strength change of 8.68 ksi, the unirradiated USE for the surveillance weld is estimated to be 128 ft-lbs.The irradiated Charpy data for the capsule weld material was analyzed using the SAM McFRAC code[McFRAC], This code is based on a non-linear, least squares, regression analysis using the Weibull statistic.

The Weibull statistic has been shown to be the correct statistic for analysis of fracture data by considering the microstructural mechanisms involved in the fracture of ferritic, pressure vessel steels[MA85b].The confidence bands calculated by McFRAC are measures of'the goodness of fit'nd do not indicate the engineering 95%statistical error spread, This uncertainty must be analyzed using conventional statistical methods.However, the McFRAC confidence intervals are used to measure confidence in the 10 I t'4 I p.('I ,t I fit of a particular data set as well as the inherent scatter due to the fracture process.These error bands must be calculated, particularly for sparse data sets, because in many cases the ability to fit sparse data drives the uncertainty.

The McFRAC analysis for the irradiated capsule weld is shown in Figure 2-3.Using the results of the McFRAC fit, the confidence interval for energy measurement (2a~)at the 50 ft-Ib level was estimated to be 13.5 ft-lbs.This estimate is consistent with the uncertainty in determination of the USE for tests conducted on the upper shelf.The minimum unirradiated USE data for the beltline welds reported in Reference[MA92a]is shown in Table 2-1.These data were determined assuming that the Charpy behavior of the surveillance weld is similar to the response for the beltline welds.Weld W5214/5613F was not made using the same wire heat or flux lot as'he beltline welds.However, the weld materials were manufactured by the same suppliers, the weld wire type and flux type are the same (RACO¹3 wire, Arcos B5 flux), the same procedure was used, and the Cu and Ni content is representative of the beltline welds[CE90, MA91].Therefore, it has been assumed that the capsule weld material is similar to the beltline welds in terms of its mechanical behavior response.At the time the Reference[MA92a]analysis was performed, the results of the uncertainty analysis reported herein were not available.

Therefore, engineering judgement was applied to obtain reasonable yet conservative estimates of the.unirradiated USE levels.To ensure conservatism, the measured irradiated USE was used as an estimate of the unirradiated surveillance weld USE.In estimating the beltline weld USE, this value was decreased to account for uncertainty in the yield strength model estimate.In order to estimate the beltline weld unirradiated metal USE levels, the measured irradiated USE for the surveillance weld (110 ft-Ibs)was reduced by 2a, (13.5 ft-Ibs)plus an additional 6.5 ft-Ib for conservatism.

This lower bound estimate of 90 ft-Ibs was conservatively assumed to represent the unirradiated USE of the beltline welds.11 0'

Table 2-1 Estimated Upper Shelf Energy for NMP-1 Beltline Welds[MA92a]Material wt.%cu Minimum Unirrad.USE (ft-Ib)Irradiation Decrement aUSE (%)12/16/91 Irradiation Decrement AUSE (%)EOL(25 efpy)'redicted USE 12/16/91 (ft-Ib)Predicted USE at EOL(25 efpy)'ft-Ib)

W5214/5G13F 0.18 86054 B/4E5F 0.22 1248/4M2F 0.22-100'0 90 17 20-20 20 23 23 83.0 72.0 72.0 80.0 69.3 69.3'ower bound estimate based on irradiated value measured at a fluence of 4.78 x 10" n/cm'Conservatively estimated using data in[MA90]and[MA91]'ast fluence of 7.26 x 10" n/cm't the peak 1/4T position'ast fluence of 1.44 x 10" n/cm't the peak 1/4T position'ata from Reference[CE90]'urveillance Weld 12 CC('

300 WELD PLATE EST.MEAS.UNCERTAINTY

~EST.MEAS.UN CERTAINTY O CI f~~~~~0~350 0 b~o>(MPa)Wa(MPa)13 Figure 2-1 Plots of Transition Temperature Shifts Indexed at 41 J (Joules)Versus Static Yield Stress Changes for (a)Weld and (b)Plate and Forgings[OD86]

0.7 uf X N A X O I D USE'SED g-Q~WELD o PLATE ou~~&+~0 0 e 0~'0 0~~8o 4 o~0 o<<po he>(MPI)Figure 2-2 Fractional Decreases in CUpper Shelf Energy Versus Yield Stress Changes[OD86]14 h g Ql 125 I I-100 CS V5~50 O 26 CL A 4 4 Oa g4/Qkiki~gg Jk~p~//k 300-TEST TEMPERATURE (F)NINE MILE POINT UNIT WELD 5 2 I 4./5G 1 3F (SURVEILLANCE WELD)-150 IRRADIATED DATA WEIBULL FIT TRANSITION WEIBULL FIT UPPER SHELF HYPERBOLIC TANGENT FIT CONFIDENCE LIMIT (95+)CONFIDENCE LIMIT (96%)CONFIDENCE LIMIT (86%)CONFIDENCE LIMIT (95%)UNIRRADIATED DATA UNIRRADIATED CHARPY CURVE Figure 2-3 Charpy Impact Energy Versus Test Temperature for Irradiated Weld Specimens from the Nine Mile Point Unit 1 300 Degree Capsule 15

'14l()" f.+J ((l, 4

3.0 Uncertainty

Estimation The basic approach to characterizing the uncertainty associated with estimating the unirradiated USE using the yield strength model described in Section 2.0 is to apply the model to LWR data for which the unirradiated USE is known, and then to determine the uncertainty by plotting the calculated USE versus the measured USE and determining the two sigma limits, The following steps were followed:~Extract weld data from the LWR database for which the unirradiated USE (USE'), irradiated USE (USE'""), and change in yield strength (hGy)data are available.

The Reference[PREDB]database was used.~Calculate USE'sing the yield strength model;~Calculate the two sigma limits for USE'calculated) vs.USE'measured)

Details related to the uncertainty evaluation are provided in Sections 3.1 and 3.2 of this report which follow.During the analysis, it was discovered that the functional form of the yield strength model should be updated.The details concerning model update are described in Section 3.3.The updated model was applied to the NMP-1 surveillance weld, and these data are presented in Section 3.4.Comparison of the uncertainty in yield~~~~~~~strength and USE measurements with the uncertainty in the yield strength model is presented in Section 3.5.3.1 Database Analysis The NRC provided the latest version of the Power Reactor Embrittlement DataBase (PR-EDB)[PREDB]for use in the weld USE uncertainty evaluation.

The Charpy shift database (SHFT PR,DBF)and the tensile database (TEN PR.DBF)files were analyzed and reduced, subject to the following criteria, to produce the final combined weld uncertainty analysis data set:~Only weld records were used in the analysis.~Records were eliminated which do not have the minimum data required to calculate the model uncertainty (USE;USE'"", and do).~Records were eliminated in cases where the reported Charpy fluence was not within 40%of the reported tensile fluence.~Records were eliminated if the unirradiated tensile test temperature was greater than 50 degrees above or below the irradiated tensile test temperature.

~Whenever possible, hadata at 550'F were used.If 550'F data were not 16

'vailable, data at the next highest temperature was used.As discussed in Reference[OD86], temperature effects on daare small.~Lower yield strength data were used to calculate do~~Records were eliminated if the capsule and heat identification in the tensile database does not match the capsule and heat identification in the Charpy database for a particular plant.T~Average stress values were used to calculate dowhenever results for more than one tensile test were available at the test temperature, material, and fluence conditions of interest.~All database units were converted to U.S.conventional units (ha=ksi, USE=ft-lbs).~The final data set contains only weld data for commercial BWR and PWR plants irradiated between 520'F and 590'F,~If the Charpy data reported in the PR-EDB indicates an increase in the USE with irradiation, and the increase is larger than 15 ft-Ibs (it was assumed that the USE measurement uncertainty is+15 ft-Ibs at the two sigma level), then these data were not included in the analysis (see discussion on outliers which follows).Otherwise, the d USE was set equal to zero for cases where the USE increased by less than 15 ft-lbs.~If the tensile data reported in the PR-EDB indicates a decrease in yield strength with irradiation, and the decrease is larger than 5 ksi (it was assumed that the yield strength measurement uncertainty is+5 ksi), then these data were not included in the analysis (see discussion on outliers which follows).Otherwise the b,owas set equal to zero for cases where the yield strength decreased by less than 5 ksi.The reduced data set obtained by application of these criteria is shown in Table 3-1.The data set contains 145 weld records, which is significantly larger than the 32 weld records available at the time the yield strength model was originally developed.

3.1.1 Analysis

of Outliers The data records for which the yield strength decreased by more than 5 ksi and/or the USE increased by more than 15 ft-Ibs are summarized in Tables 3-2 and 3-3, respectively.

For the Callaway plant, based on the data trends, there appears to be an error in the unirradiated aat 550'F (Table 3-2).Therefore, 17

~k s'f 1 (tl 0 k,'I JC the RT odata was used to calculate doin the uncertainty analysis.For Oconee 3 (Table 3-2), there appears to be an error or anomaly for the daat.550'F for Capsule B.The data trends suggest an error in the irradiated ovalue.Therefore, for this capsule, the RT dewas used in the uncertainty analysis.Similarly, for Vermont Yankee, there appears to be an error in the yield strength for the irradiated specimen tested at 543'F.Therefore, the RT hawas used in the uncertainty analysis.For Dresden 3 (Table 3-3), an interesting USE versus fluence trend was observed.For fluences below about 1 x 10" n/cm', the USE appears to increase by a statistically significant amount, Above the 1 x 10" n/cm'luence, the USE decreases as expected, Therefore, the first data column in Table 3-3 was eliminated from the uncertainty analysis.The Vermont Yankee Capsule 30D, which was irradiated to 4.3 x 10" n/cm', shows a similar behavior to that of the Dresden Capsule 6.Below about 1 x 10" n/cm', the USE appears to increase slightly.Table 3-3 also lists an outlier for the Garigliano plant.In this case, a statistically significant USE increase and a statistically significant increase in yield'strength at a fluence of 7 x 10" n/cm'as reported.This datum is inconsistent with the data trends of the other Garigliano capsules, and therefore, was not included'in the USE uncertainty evaluation, After the PR-EDB was assembled, Oak Ridge National Lab (ORNL), in cooperation with the Electric Power Research Institute (EPRI), performed additional verification of the database.However, not all data could be verified by the reactor vendors, and the PR-EDB contains a list of the reactors, capsules, and files which were not verified.None of the previously discussed outliers were on the PR-EDB unverified list.3.1.2 Summary As with most outlier analyses, there is not sufficient information available to draw firm conclusions regarding the cause of the anomalies.

However, the data in Table 3-2 suggest that the few cases of dodecrease may be due to data error.For the three cases listed in Table 3-3 which show a statistically significant USE increase, two of these (Dresden 3 Capsule 6 and Vermont Yankee)occur at very low fast fluences ((1 x 10" n/cm').The Garigliano datum appears to be a data error since it is inconsistent with the other Garigliano capsule data.Based on the analyses performed, it is concluded that the yield strength increases continuously with neutron irradiation, in agreement with the earlier observations made by Odette et.al.[OD86].With the possible exception of low 18 I S fluence irradiation, the USE decreases with fluence, which is also consistent with the model reported in Reference[OD86].N 3.2 USE Estimation Uncertainty The yield strength model (Section 2.0)was applied to the reduced weld data set described in Section 3.1.The results of the analysis are shown in Table 3-1 and in Figure 3-1.The SYSTAT[SYSTAT]code package was used to perform a linear least squares regression analysis on the measured (USE'~,)versus predicted (USE'~Q unirradiated USE data.The calculated slope (Figure 3-1)of the regression model is 0.988 with a residual squared (R')value of 0.986.The regression analysis identified D.C.Cook Unit 1 Capsule U (Case 23), Garigliano Capsule 114A (Case 49), and McGuire 2 Capsule X (Case 69)as possible outliers.The two sigma scatter band was determined to be 23.99 ft-lbs.This is the best estimate of the uncertainty in the yield strength model and can be used as a conservative adjustment to the estimated USE'.In the case of the NMP-1 surveillance weld, the estimated USE'f 128 ft-Ib (Section 2,2)may be reduced to 104 ft-Ibs to account for the uncertainty in the USE estimation model.This reduced USE'stimate is consistent with the 100 ft-Ib obtained using engineering judgement (See Table 2-1).3.3 Yield Strength Model Update A plot of the Reference[OD86]model along with the current weld data set is shown in Figure 3-2.Although the data set used in the mid-1980s suggested a possible nonlinear dependence of the fractional.

decrease in USE (f)with increase in yield strength (ho), Figure 3-2 shows that a linear dependence is more-appropriate.

As shown in Figure 3-2, the[OD86]model tends to underpredict the USE for low ho(-<8ksi), and tends to overpredict at higher halevels.A linear least squares regression was performed on the current LWR weld data set, The results are shown in Figure 3-3.The linear and non-linear models are compared in Figure 3-4.The regression yielded an R'alue of 0.880.The two sigma scatter band was determined to be 0.182.This two sigma value is lower than the scatter estimate of+0.2 reported in[OD86]for the non-linear model.Therefore, based on the analyses performed, it has been concluded that the fractional decrease in USE depends linearly on hofor LWR weld metals.The proposed linear function is: f 0 015 bay (3-1)19 II 1I lI~',I 1I where, f=fractional decrease in USE ba=increase in yield strength (ksi)3.4 Application of Updated Model to NMP-1 Welds The linear yield strength model was applied to the LWR weld data set to estimate the uncertainty in calculating the unirradiated USE in a similar manner as described in Section 3,2 for the non-linear model.The results are shown in Table 3-4 and Figure 3-5.The calculated slope of the regression line is 0.979, which is close to unity.The R'alue is 0.986 which is identical to the results obtained for'the non-linear model.The regression analysis identified D.C, Cook Capsule U (Case 23)and Gangliano Capsule 114A (Case 49)as possible outliers.The two sigma scatter band was determined to be 23.69 ft-lbs, which is slightly lower than the 23.99 ft-Ibs obtained using the non-linear model.Overall, the uncertainty for the linear and non-linear models is approximately the same.This is because the uncertainty due to mechanical behavior testing is large and dominates the impact of the functional form of the yield strength model.Applying the linear model to the NMP-1 surveillance weld results in an estimated unirradiated USE of 126 ft-lb.This estimate is slightly more.conservative than that obtained earlier using the non-linear model.Subtracting the two sigma estimate of 24 ft-Ibs yields a lower bound unirradiated USE of 102 ft-lbs.As mentioned earlier, this USE level is consistent with earlier estimates based on engineering judgement.

3.5 Tensile/USE Measurement Uncertainty A cursory examination of Figure 3-3 suggests that the scatter in hodata taken from the LWR database is significantly larger than the expected uncertainty in yield strength measurement, For uniaxial testing of steel, an uncertainty on the order of+5 ksi is typical.Therefore, a limited investigation was performed to address this question.The uncertainty for yield strength measurement of nuclear pressure vessel steels was characterized and these data are presented in Section 3.5.1 below.A similar study was performed for USE determination to see if the yield strength model uncertainty is consistent with the mechanical property measurement uncertainty, and these results are presented in Section 3.5.2 below.3.5.1 Tensile Uncertainty Analysis The PR-EDB database file TEN PR.DBF was used to identify plants for which three or more tensile tests had been performed.

The plants, along with 20

,ll J'L t-T mean lower yield strength and two sigma estimates, are shown in'Table 3-5.The average two sigma estimate is 3.2 ksi.Most of the data with 3 or more yield strength measurements are for unirradiated material.Most of the surveillance capsules contain 3 tensile specimens for each capsule material (base, weld, HAZ), and these are usually tested at room temperature (RT), 550'F, and at an intermediate temperature.

Further, not all plants have multiple yield strength data in the unirradiated condition.

For many of the data shown in Figure 3-3, only one unirradiated, odatum and one irradiated adatum were used to calculate dc>.The correlation for daversus fractional decrease in USE is shown in Figure 3-6.The two sigma limit for the LWR weld data is 11.3 ksi.This two sigma limit is significantly larger than the multiple specimen (3 or more measurements) two sigma uncertainty as a result of insufficient number of test specimens required to accurately characterize ho.3.5.2 USE Uncertainty As mentioned in Section 2.2, an uncertainty of 13.5 ft-Ibs was used in the NMP-1 surveillance weld analysis.This estimate was determined based on the surveillance capsule data.In order to obtain an estimate of the USE uncertainty in the LWR database, ten plants were randomly selected from the PR-EDB database.The plants, along with hyperbolic tangent fits to their weld data, are shown in Figures 3-7 through 3-16.As shown in the figures, there is usually'ufficient data available for accurate determination of the unirradiated USE.However, since only 8 to 16 Charpy specimens are available in most surveillance capsules, data for USE characterization on the upper shelf is generally limited, In order to estimate the uncertainty in USE measurement in the unirradiated condition, the data for each of the plants was fit using a linear regression model, The equation used is listed below: USE=A, T+A where Ai regression coefficients T=test temperature.

The fracture appearance data were used to identify upper shelf points.After each model regression was completed, the midpoint of the temperature range over which the USE measurements were made was calculated.

Each set of data were shifted up or down at the midpoint temperature to yield normalized data distributed around a 100 ft-Ib mean.The normalized data were fit using Equation 3-2, and the results are shown in Figure 3-17.The two sigma limit for 21 4'l 5'**If the normalized data was calculated to be 19.8 ft-lbs.3.5.3 Summary The two sigma limit for USE measurement was estimated to be 19.8 ft-Ibs for unirradiated weld metal.Since, for most plants, the unirradiated USE is determined using 9 or more specimens, and the irradiated USE is determined using 3 or more specimens, the uncertainty in calculating the fractional decrease in USE (f)is expected to be on the order of the uncertainty in USE measurement.

As shown in Figure 3-3, this is the case for LWR weld metals since the two sigma limit for"f" was found to be+0.18.The two sigma limit in correlating hc with fractional decrease in USE (Figure 3-6)(-11 ksi)is more than twice tie two sigma limit associated with yield strength measurement

(Ž3-5 ksi).This is believed to be due mainly to the fact that the current industry practice in surveillance testing is to perform only one tensile test at each temperature.

In addition, there are only a few plants which have baseline tensile data determined using multiple specimens.

In the future, for those plants which use the yield strength model to estimate the unirradiated USE, more accurate results can be obtained by allocating more specimens to testing at a given temperature and/or through the use of miniature specimens.

22

'.C V II (f Teble 3-1 LWR Weld Data and Non-Linear Yield Strength Model Estimates Of the Unlrradlated USE~Plan Unirradiated Irradiated USE USE (Measured)(Measured)

USE4~USE ups USE~USE Calculated Measured Fractional Fractional USE USE~Chan e~Chan e Uniiradiated USE (Calculated)

USE'cAi USE'~MS E'cN~flub~4b CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 1 2 3 4 5 6 7 8 9 10 ll 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 3031 32 33 34 35 36~37 38 39 40 41 42 43 44 45 46 47 48 49 50 ANO-1 ANO-1 ANO-1 ANO-2 Angra Beaver Val 1 Beaver Val 1 Beaver Val 1 Big Rock Big Rock Big Rock Big Rock Cal Cliffs 1 Cal Cliffs 2 Callaway 1 Callaway 1 Catawba 1 Crystal Riv3 Crystal Riv3 Crystal Riv3 Crystal Riv3 D.C.'Cook 1 D.C.Cook 1 Davis Besse Davis Besse Davis Besse Davis.Besse Davis Besse Diablo Can 1 Diablo Can 2 Dresden 2 Dresden 3 Dresden 3 Dresden 3 Dresden 3 Dresden'3 Dresden 3 Dresden 3 Duane Arnold Parley 1 Farley 1 Parley 1 Farley 2 Farley 2 Farley 2 Ft.Calhoun Ft.Calhoun Garigliano Garigliano Carigliano 73.000 73.000 73.000 154.000 171.000 112.000 112.000 112.000 95.000 95.000 95.000 95.000 160.000 137 F 000 112.000 112.000 128.000 79.000 79.000 79.000 79.000 110.000 110.000 70.000 70.000 70.000 72.000 72.000 98.000 121.000 71.000 65.000 65.000 65.000 65.000 70.000 70+000 70.000 101.000 149.000 149.000 149.000 144 F 000 144.000 144.000 104.000 104.000 103'00 103:400 103.400 45.000 47.000 58.000 147 F 000 155 F 000 78.000 83.000&8.000 65 F 000 70 000 57 F 000 80+000 119 F 000<05~000 97.000 10lo000 123 F 000 68.000 64.000 70.000 63 F 000 80.000 94 000 57.000 54.000 64 000 62.000 65.000 87.000 85 000 52.000 45.000 41 F 000 42.000 65.000 59 000 64+000 70~000 101~000 108.000 1300000 115.000 144 F 000 144 F 000 132.000 59~000 650000 79'00 67'00 60.000 28.000 26.000 15.000 7.000 16.000 34.000 29 F 000 24.000 30.000 25.000 38.000 15.000 41.000 32.000 15.000 11.000 5.000 11.000 15.000 9.000 16.000 30.000 16.000 13.000 16.000 6.000 10.000 7.000 11.000 36.000 19.000 20.000 24.000 23.000 0.000 11.000 6.000 0.000 0.000 41-000 19.000 34.000 0.000 0.000 12.000 45.000 39.000 23.800 36~100 43.400 12.830 12.830 8.430 3.100 0.000 19.900 16.800 15 800 17'00 15.300 12~100 7.500 12.200 10.900 8.000 0.000 4 300 10.680 10.480 1.880 10.680 19.050 22'50 10.200 10.500 F 500 11~800 5.500 14.700 16.600 17 600 20.370 25.170 16.570 0.400 20.830 13.230 2'30 0 000 6.550 12.250 8.150 1.350 6.450 5.350 21.100 22.100 14.930 36.410 18.490 0.219 0.219 0.137 0.019 0.000 0.321 0.278 0 264 0'94 0.257 0.207 0.115 0'09 0.186 0.128 0.000 0'27 0'82 0~179 0~012 0~182 0'09 0.357 0.173 00179 0.034 0.202 0'34 0'48 0 276 0.290 0'27 0 387 0'75 0 F 002 0'33 0 225 0 013 0.000 0.086 0.209 0 131 0.008 0.082 0'33 0 336 0 349 0'51 0.516 0 302 0 384 0.356 0.205 0.045 0.094 0.304 0.259 0.214 0.316 0.263 0.400 0.158 0.256 0.234 0.134 0 098 0.039 0.139 0 190 0.114 0.203 0.273 0.145 0.186 0.229 0.086 0.139 0.097 0.112 0.298 0.268 0.308 0 369 0.354 0 000 0.157 0.086 0.000 0.000 0.275 0.128 0.228 0.000 0.000 0.083 0.433 0.375 0.230 0.349 0.420 57.607 60 167 67.243 149.847 155+000 114 821 115 025 119.583 92.035 94~187 71.869 90'94 150.357 129.028 111 177 101~000 126+413 83.157 77 918 70.850 77'43 115.836 146.276 68'60 65 773 66 253 77 680 67 288 115.673 117 337 73'99 66+851 66.919 57.944 65'30 88'36 82.606 70.922 101 000 118.173 164.428 132'45 145~161 156.918 136 505 88'02 99 871 106.321 139.191 85.937 15.393 12.833 5.757 4'53 16.000-2.821-3 025-7.583 2.965 0.813 23.131 4.606 9.643 7.972 0.823 11.000 1.587-4.157 1.082 8~150 l.957-5.836-36.276 l.040 4.227 3.747-5.680 4.,712-17.673 3.663-2.199-l.851-1.919 7.056-0.130-18.436-12.606-0'22 0.000 30.827 15~428 16.655-l.161-12.918 7.495 15.098 4 129-2.921-35.791 17.463 23

<<)$tl Table 3-1 LWR Weld Data and Non-Linear Yield Strength Model Estimates of the Unlrradlated USE (Continued)

~Plan Unirradiated Irradiated USE USE (Measured)(Measured)

USE'~USE Mrs USE'~-USE Calculated Fractional USE~Chan a Unirradiated Measured USE Fractional (Calculated)

USE.USE'~USE'~-USE'oAl Cbanlbe~db~lb 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 100 Garigliano Garigliano Garigliano Garigliano Ginna Ginna Ginna Haddan Neck Indian Pt.2 Indian Pt.3 Kewaunee Kewaunee Maine Yankee Maine Yankee Maine Yankee Maine Yankee McGuire 1 McGuire 1 McGuire 2 McGuire 2 Millstone 2 Millstone 2 North Anna 1 North Anna 1 North Anna 2 North Anna 2 Oconee 1 Oconee 1 Oconee 1 Oconee 2 Oconee 2 Oconee 2 Oconee 3 Oconee 3 Oconee 3 Palisades Palisades Prarie Zsl 1 Prarie Isl 1 Prarie Zsl 1 Prarie Isl 2 Prarie Isl 2 Prarie Isl 2 Pt.Beach 1 Pt.Beach 1 Pt.Beach 1 Pt.Beach 2 Pt.Beach 2 Pt.Beach 2 (tuad City 1 103.400 103.400 103.400 103.400 80.000 80.000 80.000 105.000 118 000 120.000 126.000 126.000 105.000 105.000 105.000 105.000 112 F 000 112.000 133.000 133.000 132.000 132.000 95.000 95.000 112.000 115.000 64.000 64.000 64.000 67.000 67.000 68.000 66.000 66>>000 66 F 000 118 F 000 118 000 79.000 79.000 79.000 103.000 103>>000 103 F 000 65.000 65.000 65.000 65.000 65.000 66 000 72.000 51.400 83.900 103.400 73.800 53.000 51.000 50.000 83~000 75.000 68.000.78.000 82.000 57.000 59>>000 66 F 000 50.000 83~000 75 F 000 133.000 133 F 000 98.000 108.000-95.000 92 F 000 112~000 92 F 000 52.000 52.000 55 F 000 44.000 47.000 54.000 49.000 58.000 42 000 52 F 000 64 F 000 79.000 75.000 79 F 000 91.000 100 F 000 92.000 54.000 55.000 51.000 42.000 47.000 44.000 49.000 52~000 19.500 0.000 29.600 27.000 29 F 000 30.000 22.000 43 000 52.000 48.000 44 F 000 48.000 46 F 000 39.000 55.000 29.000 37 000 0.000 0.000 34.000 24 F 000 0>>000 F 000 0.000 23 F 000 12~000 12.000 F 000 23>>000 20.000 14 F 000 17.000 8.000 24 F 000 66.000 54.000 0 000 4.000 0.000 12.000 3.000 11>>000 ll>>000 10.000 14.000 23.000 18.000 22 F 000 23.000 24 890 0.000 0.710 23.750 21.750 22.850 19.650 16.750 25 800 24.800 27 750 23'50 30.670 23.720 24.970 36.170 19.900 13 800 10.950 7.350 6.070 10.270 2 650 10.850 5.450 2.500 19.300 16.700 13.500 18.770 16.420 10>>770 15 700 5.200 19.200 32.660 25.510 8'50 12.650 4.950 17 F 000 8.450 7.850 19.300 20.300 19.800 18.070 19.970 20.570 29.000 0~384 0.000 0 004 0.370 0 345 0.359 0.317 0.278 0~395 0.383 0.418 0 369 0.452 0.370 0.385 0.514'>>321 0.234 0.187 0.111 0.065 0.175 0.016 0.185 0.034 0.016 0~313 0.277 0.229 0.306 0~273 0.184 0.263 0 032 0~311 0.475 0.391 0.129 0.216 0~031 0.281 0.138 0.124 0.313 0.326 0.319 0.296 0.322 0.329 0.433 0.503 0.189 0 000 0.286 0.338 0.363 0~375 0~210 0.364 0.433 0.381 0 349 0.457 0.438 0.371 0.524 0~259 0.330 0 F 000 0.000 0~258 0.182 0.000 0.032 0.000 0.200 0.188 0.188 0>>141 0.343 0 299 0.206 0.258 0.121 0.364 0~559 0.458 0.000 0.051 0 000 0 117 0.029 0.107.0~169 0.154 0.215 0.354 0.277 0.333 0.319 83.428 83.900 103.815 117.119 80.879 79.518 73.246 114.913 123.958 110.176 134.076 129.877 104.056 93.577-107.296 102.851 122 181 97.932 163'15 149'01 104 F 800 130.869 96 545 112~929 115~942 93.496 75.660 71.923 71.381 63.364 64.652 66.168 66.455 59.917 60~991 99.018 105.168 90;670 95.655 81.527 126.607 115.997 105.009 78.570 81.595 74'29 59.666 69.281 65.620 86'05 19'72 19 500-0.415-13~719-0~879 0~482 6:754-9'13-5.958 9.824-8.076-3.877 0.944 11.423-2.296 2.149-10.181 14>>068-30.615-16 601 27.200 1.131-1.545-17.929-3.942 21.504-11 660-7 923-7'81 3.636 2 348 1.832-0.455"6>>083 5.009 18 982 12.832-11.670-16.655-F 527-23.607-12.997-2'09-13.570-16 595-9 929 5.334-4.281 0.380-14.405 24

$1 fy I I 4$/

Table 3-1 LWR Weld Data and Non-Linear Yield Strength Model Estimates of the Unlrradlated USE (Continued)

~Plan Unirradiated Irradiated USE USE (Measured)(Measured)

USE'M~USE~USE'M~-USE Calculated Fractional USE~Chan a Unirradiated Measured USE Fractional (Calculated)

USE USE'oM USE'Mrhs-USE'oM

~Chan e~ltdb~Zb CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASECASE CASE CASE CASE CASE 101 102 103 104 105 106 107 108 109 110 ill 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 Quad City 1 Quad City 1 Quad City 1 Quad City 2 Quad City 2 Quad City 2 Quad City 2 Quad City 2 Rancho Seco Rancho Seco Rancho Seco Robinson 2 SONGS 2 Salen 1 Salen 2 Salen 2 Sequoyah 1 Sequoyah 1 Seguoyah 2 Sequoyah 2 Shearon Har St.Lucio 1 St.Lucie 1 Surry 1 Surry 1 Surry 2 Surry 2 THZ 1 THI 1 Trojan Trojan Trojan Turkey Pt.3 Turkey Pt.3 Turkey Pt.4 V.C.Sunner V.C.Sunner Vernont Yank Wolf Creek Zion 1 Zion 1 Zion 1 Zion 1 Zion 2 Zion 2 looeooo 100.000 looeooo 87.000 90.000~125.000 125 F 000 125.000 68.000 68.000 68.000 112.000 99.000 104.000 ill.000 111.000 111.000 111.000 112~000 112~000 94.000 144.000 144 F 000 70.000 70.000 90.000 90.000 Sle 000 eleooo 83.000 83~000 83 000 65.000 65.000 66 F 000 91.000 91eooo 107.000 looeooo 64.000 64 F 000 68.000 68.000 69 000 69eooo 85.000 95.000 75 000 41.000 51.000 107.000 89.000 80.000 51.000 48.000 53.000 70 000 80 000 75.000 79 F 000 74.000 82 000 78.000 109 000 110.000 82.000 108.000 100.000 53~000 50 000 60.000 70 F 000 50eooo 64 000 81.000 62.000 83.000 48eooo 59eooo 44.000 87 000 85.000 107.000 92eooo 44 F 000 52.000 56.000 49 F 000 50.000 51.000 15.000 5.000 25.000 46.000 39.000 18.000 36.000 45.000 17 F 000 20.000 15.000 42.000 19.000 29.000 32.000 37 000 29.000 33 000 3 000 2.000 12.000 36.000 44.000 17.000 20.000 30.000 20.000 31.000 17.000 2 000 21.000 0~000 17.000 6.000 22.000 4.000 6 000 0.000 8.000 20.000 12.000 12eooo 19.000 19.000 18.000 14~600 3.200 18.200" 29.700 18.600 0.400 8 100 14.700 14.000 11.000 25.050 23.150 16.100 21.000 18.700 20e700 10 100 11.800 5.550 6.050 6.000 6'30 9.330 19.750 24'50 18.500 10.300 14'70 11.750 3'00 6 300 6 300 20.850 18~550 21.040 0-800 5.000 4.800 0.900 18.200 16.000 13 400 16.000 18~500 24 500 0 246 0.020 0.298 0.441 0.303 0.002 0.130 0 248 0.237 0.188 0.386 0.362 0.268 0.335 0.305 0'31 0.172 0'02 Oe034 0.064 0~061 0.099 0.157 0.319 Oe377 0.302 0~175 0'50 0~201 0'22 0.076 0.076 0~333 0~303 0'36 Oe005 Oe 031 0 030 0.006 0~298 0 F 267 0.228 0.267 Oe302 0.379 0.150 0.050 0.250 0.529 0.433 0.144 0.288 0.360 0.250 0.294 0.221 0.375 0.192 0.279 0.288 0.333 0.261 0.297 0.027 0.018 0~128 0.250 0.306 0'43 0.286 0.333 0.222 0.383 0.210 0.024 0.253 0.000 0.262 0.092 0.333 0.044 0.066 Oeooo 0.080 0.313 0 188 0.176 0~279 0.275 0~261 112.789 96.939 106.816 73.350 73.202 107 214 102.286 106 366 66.863 59.113 86.299 109.786 109.356 112.791 113.613 110.640 98.981 97.726 112.836 117.488 87.294 119.840 118.561 77 792 80.293 85.953 84'80 66.705 80.100 82'22 67 113 89.844 71.976 84.603 66.222 87.437 87.719 110.309 92.555 62.666 70 942 72.531 66'49 71.628 82.142-12.789 3.061-6.816 13.650 16.798 17.786 22.714 18 634 1.137 8.887-18.299 2.214-10.356-8.791-2.613 0.360 12~019 13.274-Oe836-5.488 6.706 24.160 25.439-7.792-10.293 4.047 5.120 14.295 0.900 0.178 15.887-6.844-6.976-19.603-0.222 3.563 3.281-3.309 7.445 1~334-6.942-4.531 l.151-2.628-13.142 0 I I 0 Table 3-2 Analysis of Tensile Data Outliers'ensile Data (ksi)Callaway Callaway Oconee 3 Oconee 3 Oconee 3 Vermont Yankee T t C Chti~CI U~CI Y'~CI A~CI~~CI 0.~CI 30~a-unirradiated 72.5-72.5 74.9 74.9 74.9 68.0-low temperature (70'F)(70'F)(71'F)(71'F)(71'F)cr-unirradiated 67.5-intermed.temp.(300'F)67.5 (300'F)o-unirradiated

-high temp.o-irradiated

-low temp.80.0 (550'F)71.3 (73'F)80.0 (550'F)80.5 (70'F)67.4 (580'F)79.3 67.4 (580'F)90.6 67.4 (580'F)98.0 67.6 (543'F)72.8 a-irradiated 68.2-intermed.temp.(150'F)78.4 (125'F)o-irradiated

-high temp.ha-low temp.65.7 (550'F)-1.2 64.2 (550'F)8.0 72.6 (580'F)4.4 57.8 (585'F)15.7 86.6 (580'F)23.1 57.5 (543'F)4.8 d a-intermed.

temp.0.7 10.9 ho-high temp.-14.3-15.8 5.2-9.6 19.2-10.1'he data in this table exhibit yield strength decreases greater than 5 ksi.The data from left to right are in the order of increasing fluence for each plant.26

Table 3-3 Analysis of Charpy Data Outliers Charpy Data'ft-Ibs)Dres.3 Ores.3 Dres.3 Dres.3 Test CondiTion~Ca.6'Ca.6'Ca.0'~Ca.14 Dres.3~Ca.14 Dres.3 Dres.3 Dres.3 Garigliano

~Ca.4~Ca.4~Ca.12~Ca.113D VT Yankee'Ca.30D Unirradiated USE'0 65 70 65 70 70 65 65 103.4 Irradiated USEIRR USE'-USE'30 5 0.4 2.03 106 71 75 45 20 20.4 13.2 59 41 42 123.7 11 24 23-20.3 20.8 25.2 16.6 21.48-15 See Table 2-4'he data for Dresden 3 are listed from left to right in the order of increasing fluence.All fast fluences, except those noted, are above 1.0 x 10" n/cm'Data for fast fluence=4.3 x 10" n/cm'Data for fast fluence=2.75 x 10" n/cm'Data for fast fluence=0.95 x 10" n/cm'.27 yt C Table 3A LWR Weld Data and LInear Yield Strength Model Estimates of the Unlrradlated USE~Plan Unirradiated Irradiated USE USE (Measured)(Measured)

USE'hf~USE ups USE M~USE Lfaas her Unlrradiated Calculated Measured USE'ractional Fractional (Calculated)

USE USE USE'~USE'~-USE'ofhL,~Chan a~Chan a~ftdb~fl-Ib CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 ANO-1 ANO-1 ANO-1 ANO-2 Angra Beaver Val 1 Beaver Val 1 Beaver Val 1, Big Rock Big Rock Big Rock Big Rock Cal cliffs 1 Cal Cliffs 2 Callavay 1 Callavay 1 Catawba 1 Crystal Riv3 Crystal Riv3 Crystal Riv3 Crystal Riv3 D.C.Cook 1 D.C.Cook 1 Davis Besse Davis Basso Davis Besse Davis Besse Davis Besse Diablo Can 1 Diablo Can 2 Dresden 2 Dresden 3 Dresden 3 Dresden 3 Dresden 3 Dresden 3 Dresden 3 Dresden 3 Duane Arnold Farley 1 Farley 1 Farley 1 Farley 2 Farley 2 Farley 2 Ft.Calhoun Ft.Calhoun Garigliano Garigliano Garigliano 73nooo 73.000 73.000 154 F 000 171nooo 112.000 112.000 112~000 95.000 95.000 95 F 000 95.000 160 F 000 137.000 112.000 112 F 000 128.000 79 F 000 79.000 79 F 000 79 F 000 110.000 110.000 70.000 70.000 70~000 72.000 72.000 98 F 000 121 F 000 71.000 65.000 65.000 65.000 65.000 70 F 000 70.000 70 F 000 101.000 149;000 149.000 149.000 144.000 144.000 144.000 104 000 104.000 103.400 103.400 103.400 45.000 47 F 000 58~000 147.000 155.000 78.000 83.000 88.000 65.000 70.000 57~000 80.000 119.000 105.000 97 F 000 101.000 123 F 000 68 F 000 64aooo 70.000 63.000 80.000 94.000 57~000 54~000 64.000 62.000 65 000 87.000 85aooo 52~QQQ 45.000 41.000 42.000 65.000 59.000 64.000 70.000 101~000 108.000 130 F 000 115.000 144.000 144.000 132.000 59.000 65.000 79'00 67.30Q 60aooo 28.000 26.000 15.000 F 000 16.000 34aooo 29.000 24.000 30.000 25.000 38.000 15.000 41.000 32.000 15.000 11.000 5.000 11.000 15.000 9.000 16.QQQ 30.000 16.000 13~000 16.000 6.000 10.000 F 000 11.000 36.000 19.000 20.000 24.000 23 F 000 0.000 11.000 6 000 0.000 Onooo 41.000 19.000 34 000 0~000 0 000 12.000 45.000 39.000 23.800 36a100 43.400 12~830 12~830 8.430 3nloo Onooo 19.900 16.800 15.800 17 900 15 a 300 12 F 100 7'00 12 200 10.900 8.000 0.000 4.300 10.680 lon480 1.880 1Q~6&0 19.050 22.750 10'00 10.500 5 F 500 11~800 5.500 14.700 16.600 17.600 20'70 25.170 16.570 0.400 20.830 13.230 2.030 0.000 6'50 12.250 8.150 1.350 6.45o 5.350 21.100 22.100 14.930 36'10 18,490 0.192 0.192 0.126 0.047 0.000 0.299 0~252 0.237 0.269 0.230 0.182 0.113 0 183 0.164 0.120 0~000 0.065 0.160 0.157 0." 028 0.160 0 286 0.341 0.153 0.158 0.083 0.177 0 083 0.221 0.249 0.264 0.306 0.378 0 249 0~006 0.312 0.198 0 030 0.000 0~098 0.184 0.122 0.020 0.097 0.080 0.317 0.332 0.224 0.546 0.277 0 384 0~356 0.205 0.045 0.094 0.304 0.259 0.214 0.316 0.263 0.4QO 0.158 0.256 0.234 0.134 0 098 0 039 0~139 0.190 0.114 0.203 0.273 0.145 0.186 0 229 0.086 0.139 0.097 0.112 0.298 Qa268 0,308 0'69 0~354 Oaooo 0.157 0.086 0~000 0.000 0'75 0'28 0.228 Onooo o.ooo 0.083 0'33 0.375 0 230 0~349 0'20 55 724 58.201 66.396 154.169 155.000 111.190 110.963 115.334 88'59 90 850 69.640 90 141 145 655 125.523 110'27 101.000 131.480 80.972 75.937 72.031 75.018 112.006 142.694 67.296 64.095 69a755 75.334 70.845 111.610 113.182 70.652 64.799 65.869 55'92 65.392 85 812 79.845 72.198 1O1.000 119.767 159.265 131 017 146.976 159.424 143'17 86.320 97.233 102.571 148.287 83.028 17.276 14.799 6.604-0.169 16.000 0 810 1.037-3.334 6.141 4.150 25.360 4 859 14.345 11.477 1.773 11.000-3.480-1.'72 3 063 6.969 3.982-2'06-32.694 2.704 5.905 0.245 3.334 1.155-13.610 7.818 0.348 0 201-0.869 9 108 0.392-15.812 9 845'.198 0.000 29.233-10.265 17.983 2.976-15'24 0 483 17.680 6.767 0 829-44.88'7 20'72 28

Table~LWR Weld Data and Linear Yietd Strength Model Estimates of the Unlrradiated USE (Continued)

Plant Unirradiated Irradiated USE USE (Measured)(Measured)

USE ups USE uzi USE u~USE u~Unirradiated USE (Catculated)

USE'cu USE4~-USE'cu Calculated Fractional USE Measured Fractional USE~Ch>>>>>>~Cha>>>>~hdh~hdh CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 89 90 91 92 CASE CASE CASE CASE CASE 94 CASE 95 96 97 98 99 CASE CASE CASE CASE CASE CASE 100 Garigliano Garigliano Garigliano Garigliano Ginna Ginna Ginna Haddan Neck Indian Pt.2 Indian Pt.3 Kewaunee Kewaunee Maine Yankee Maine Yankee Maine Yankee Maine Yankee McGuire 1 McGuire 1 McGuire 2 McGuire 2 Millstone 2 Millstone 2 North Anna 1 North Anna 1 North Anna 2 North Anna 2 Oconee 1 Oconee 1 Oconee 1 Oconee 2 Oconee 2 Oconee 2 Oconee 3 Oconee 3 Oconee 3 Palisades Palisades Prarie Isl 1 Prarie Isl 1 Prarie Isl 1 Prarie Isl 2 Prarie Isl 2 Prarie Isl 2 Pt.Beach 1 Pt.Beach 1 Pt.Beach 1 Pt.Beach 2 Pt.Beach 2 Pt.Beach 2 Quad City 1 103.400 103.400 103.400 103.400 80.000 80.000 80 000 105.000 118.000 120.000 126 000 126.000 105.000 105.000 105.000 105.000 112.000 112.000 133.000 133.000 132.000 132.000 95.000 95 000 112 F 000 115 000 64 000 64>>000 64.000 67.000 6z.oao 68.000 66.000 66.000 66.000 118~000 118 F 000 79 000 79>>000 79>>000 103,000 103.000 103~000 65.000 65.000 65.000 6s.aao 65.000 66.000 72>>000 51.400 83.900 103.400 73 800 53.000 51.000 50.000 83.000 75.000 68.000 78 000 82.000 57.000 59.000 66.0ao 50.000 83.000 75 000 133>>000 133 000 98.000 108.000 95 000 92.000 112 F 000 92 000 52 000 52.000 55.000 44 000 4?.aao 54.000 49 F 000 58.000 42 F 000 52.000 64.000 79 000 75>>000 79.000 91.000 100.000 92.000 54.000 55 000 51.000 42.000 47.000 44.000 49.000 52.000 19.500 0.000 29.600 27.000 29.000 30.000 22.000 43 000 52.000 48.000 44.000 48.000 46.000 39 000 55.000 29.000 37 000 0.000-0~000 34 000 24.000 0>>000 3.000 0.000 23 000 12~000 12.000 9.000 23.000 20.000 14 F 000 17.000 8.000 24.000 66.000 54 F 000 0.000 4.000 0.000 12 F 000 3.000 11.000 11~000 10.000 14~000 23.000 18.000 22.000 23 000 24.890 0.000 0.710 23.750 21.750 22.850 19.650 le?50 25 800 24'00 27.750 23.650 30 670 23.720 24.970 36.170 19.900 13.800 10~950 7.350 6.070 10.270 2.650 10.&50 5.450 2'00 19.300 16.700 13.500 18.770 16~420 10.770 15.700 5.200 19~200 32'60 25.510 8.050 12.650 4 950 17~000 8.450 7.850 19.300 20.300 19'00 18.070 19.970 20'70 29.000 0.373 0.000 0~011 0 356 0.326 0.343 0.295 0.251 0.387 0.372 0.416 0.355 0.460 0.356 0~375 0.543 0'99 0.207 0.164 0'10 0.091 0.154 0.040 0.163 0.082.0.038 0.290 0~251 0.203 0.282 0 246 0,162 0.236 0.078 0~288 0.490 0.383 0.121 0.190 a.az4 0.255 0.127 0.118 0.290 0'05 0.297 0~271 0 300 0.309 0>>435 0.503 0.189 0.000 0.286 0.338 0.363 0.375 0.210 0.364 0.433 0.381 0.349 0.457 0.438 0.371 0.524 0'59 0.330 0~000 0>>000 0.258 0.182 0.000 0.032 0.000 0.200 0.188 0.188 0.141 0 343 0 299 0.206 0.258 0~121 0.364 0.559 0.458 0.000 0.051 0.000 0.117 0.029 0~107 0~169 0.154 0'15 0 354 0.277 0.333 0.319 82'23 83.900 104.513 114.641 78.664 77.596 70.897 110.851 122.349 108.280 133.619 127.083 105.565 91.586 105.524 109.302 118.31&94.578 159.138 149.480 107.817 127.667 98.933 109.884 121.971 95.584 73.188 69.380 68'66 61.243 62.359 64.405 64.094 62.907 58.989 101.941 103.669 89.849 92.564 85.336 122.148 114~515 104.279 76.003 79 F 080 72'46 57.617 67.100 63.634 86.726 21.37?19.500-1.113-11.241 1.336 2'04 9.103-5.851-4 349 11.720-7 619-1.083-0.565 13>>414-0.524-4'02-6 318 17~422-26.138-16.480 24.183 4.333-3.933-14.884-9.971 19~416-9~188-5'80-4.966 5.757 4'41 3.595 1 906 3>>093?F 011 16>>059 14>>331-10~849-13*564-6>>336-19~148-11.515-1>>279-11.003-14.080 7'46 7'83-2'00 2>>366-14'26 29 4), 4 Table 34 LWR Weld Data and Linear Yield Strength Model Estimates ot the Unirradiated USE (Continued)

~Plan Unirradiated Irradiated USE USE (Measured)(Measured)

USE'~USE~USE4~-USE Unirradiated Calculated Measured USE Fractional Fractional (Calculated)

USE USE USE'~USE4~-USE'~

CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE CASE 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 Quad City 1 Quad City 1 Quad City 1 Quad City 2 Quad City 2 Quad City 2 Quad City 2 Quad City 2 Rancho Seco Rancho Seco Rancho Seco Robinson 2 SONGS 2 Salem 1 Salem 2 Salem 2 Sequoyah 1 Sequoyah 1 Sequoyah 2 Sequoyah 2 Shearon Har St.Lucie 1 St.Lucie 1 Surry 1 Surry 1 Surry 2 Surry 2 THZ 1 THZ 1 Tro an Trojan Tro an Turkey Pt.3 Turkey Pt.3 Turkey Pt.4 V.C.Summer V.C.Summer Vermont Yank Wolf Creek Zion 1 Zion 1 Zion 1 Zion 1 Zion 2 Zion 2.100.000 100.000 100.000 87 000 90.000 125.000 125.000 125.000 68.000 68.000 68.000 112.000 99.000 104.000 111.000 111.000 111.000 111.000 112.000 112.000 94.000 144.000 144.000 70.000 70.000 90.000 90 F 000 81.000 81 000 83.000 83.000 83.000-65 F 000 65.000 66.000 91.000 91.000 107.000 100.000 64 000 64.000 68.000 68.000 69.000 69 000 85.000 95.000 75 F 000 41.000 51.000 107.000 89.000 80.000 51.000 48.000 53.000 70.000 80.000 75.000 79 000 74.000 82.000 78.000 109.000 110.000 82.000 108.000 100.000 53.000 50.000 60.000 70.000 50 000 64.000 81.000 62.000 83.000 48.000 59.000 44.000 87.000 85.000 107~000 92 F 000 44 000 52.000 56.000 49 000 50.000 51.000'5.000 5.000 25.000 46.000 39.000 18.000 36.000 45.000 17~000 20.000 15.000 42.000 19.000 29.000 32+000 37 000 29 F 000 33.000 3 000 2.000 12.000 36.000 44.000 17.000 20.000 30.000 20.000 31.000 17~000 2.000 21.000 0.000 17.000 6.000 22.000 4 F 000 6.000 0.000 8.000 20+000 12.000 12 000 19~000 19~000 18 000 14.600 3.200 18'00 29'00 18.600 0.400 8.100 14.700 14.000 11.000 25.050 23.150 16.100 21.000 18~700 20.700 10.100 11.800 5.550 6.050 6.000 6.930 9.330 19.750 24.350 18.500 10.300 14.870 11.750 3.600 6.300 6 300 20.850 18.550 21.040 0.800 5.000 4.800 0.900 18~200 16.000 13.400 16.000 18.500 24 F 500 0'19 0.048 0.273 0.446 0~279 0.006 0.122 0.221 0.210 0.165 0,376 0.347 0'42 0.315 0~281 0.311 0 152 0.177 Oe083 0.091 0.090 0.104 Ool40 0 296 0'65 0'78 0.155 0.223 0 176 0.054 0.095 0.095 0.313 0.278 0~316 0.012 0.075 0.072 0.014 0~273 0~240 0.201 0.240 0 278 0 368 0.150 0.050 0.250 0.529 0'33 0.144 0.288 0 360 0.250 0 294 0.221 0.375 0.192 0.279 0 288 0.333 0.261 0;297 0.027 0.018 0.128 0.250 0 306 0.243 0 286 0 333 0 222 0 383 0.210 0.024 0.253 0.000 0.262 0.092 0.333 0.044 0.066 0~000 0.080 0.313 0 188 0.176 0.279 0.275 0.261 108.835 99.790 103~164 73.940 70.735 107.646 101.309 102.630 64.557 57.485 84.902 107.239 105'71 109.489 109'98 107.324 96.641 94.775 118.898 120.979 90'10 120.529 116.272 75.311 78~771 83'45 82.791 64.354 77.693 85.624 68.470 91.662 69.844 81.746 64.290 88.057 91.892 115.302 93.259 60.523 68.421 70'88 64.474 69 204 80.632-8.835 0.210-3.164 13.060 19.265 17.354 23.691 22.370 3.443 10.515-16.902 4.761-6~471-5.489 1.202 3.676 14.359 16.225-6.898-8'79 3.890 23.471 27.728-5.311-8.771 6.955 7.209 16.646 3.307-2.624 14.530-8.662-4.844-16.746 1~710 2.943-0.892-8.302 6.741 3'77 4.421 2.088 3.526-0.204-11.632 30 S'

Table 3-5 Elevated Temperature Yield Strength Uncertainty Estimation'lant ANO-1 ANO-2 Calvert Cliffs 1 Calvert Cliffs 2.Crystal River 3 Dresden 1 Dresden 1 Dresden 1 Fort Calhoun Humboldt Bay Millstone 2 Maine YankeeOconee 1 Oconee 2 Oconee 3 Palisades Point Beach 2 Rancho Seco 1 St.Lucie 1 St.Lucie 2 TMI-1~Ca cele Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated CORE-6 VANE Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Unirradiated Number of Measurements 3 3 4~3 6 3 4 4 4 3 3 6 3 3 3 6 3'3 3 4 60.4 65.9 66.9 68.8 67.5 75.0 99.1 74.4 64.1 57.5 66.7 61.1 56.4 69.8 67.4 62.1 , 63.1 61.6 65.9 59,2 64,3 Two Sigma Estimate ksi 3.6 1.8 2.1 3.0 3.0 9.5 4.3'3.5 3.0 , 5.3 1.3 4.8 3.5 1.4 1.7 3.8 1,3 0.6 1.6 3.0 4.6.Average 3.7-3.2'ata for weld tensile specimens tested in the 535'F to 650'F range.Individual averages and standard deviations are for tests performed over a 50'F range.31 l l' 200 y=x~<50 100 I-Q 50 Q~~~:~)""~~""~""":~~.ge.".W.g y=0.988x.0 50 100 150 MEASURED USE (Ft-Lbs), 200 Figure 3-1 Non-Linear Yield Strength Model Uncertainty Plot Showing Measured Versus Predicted Unirradiated USE 32

1.0 I 08 Z 0.6 O UJ 0.4 O~<0.2'g.'H-------.~-t.---':----

': 0:~:)0.y~L'"'"'"""""'""""')+:~~~~:~0.0 0 10 20 30 40 INCREASE IN YIELD STRENGTH (ksi)50 Figure 3-2 Comparison of the Reference[OD86]Yield Strength Model (solid line)with Currently Available LWR Weld Data 33 ll f'i l 1.0 m~0.8 Z 0.6 O>0.4 Z 0 Q~<0.2 0.0 0 g~t,j!4~~~~~:+~~~~10 20 30 40 INCREASE IN YIELD STRENGTH (ksi)50 Figure 3-3 Yield Strength Model Based on Linear Correlation Between Fractional Decrease in USE versus ho34

~g k~

1.0 UJ c0 08 Z UJ CO 0.6 CI O D>0.4 Z 0 0~<0.2~: Linear Model Non-Linear Model 0.0 0 10 20 30 40 INCREASE IN YIELD STRENGTH (ksi)50 Figure 3-4 Comparison of the Linear and Non-Linear Model Applied to LWR Weld Data gc 200 y=x l50 CO o 100 0 50 0~10 0~~~..g.O~y~',t y=0.979x 0 0 50 100 150 MEASURED USE (Ft-Lbs)200 Figure 3-5 Linear Yield Strength Model Uncertainty Plot Showing Measured Versus Predicted Unirradiated USE 36

50 40 I-(9~30 CO'CI 20 LLj CO cc 10'O Z~:~N'l~~:.~'""'""~~~"'"'"'""'~..g.....r.

~<<4~g:.V~~~0 0.0 0.2 0.4 0.6 0.8 FRACTIONAL DECREASE IN USE 1.0 Figure 3-6 Increase in Yield Strength versus Fractional Decrease in USE 37 I t'4'I 128 IINQ UIIIY 1-WELD IIATKIclRL 188 288 888 Deg.F 88 68 48 5 r~~S g S 0~Baseline 0 A 1.83E19 ni'ca~~E 7.27E17 n/c~~I 48~58 188 iSB Test Temperature 258 Deg.C Figure 3-7 Hyperbolic Tangent Fit of ANO Unit 1 Weld Metal Data 188 HEAVER VALLEY UNIT I-WELD NAIERIAL-iSB-58 58 158 258 358 458 Deg.F 128 Pn 128 A g ox 88 68 28-158-188-SB 0 ,8 58 188 Test Temperature 88 I 68~Baseline lj 6.54E18 n/'cn>V 2.55E18 n/etc~28 9.49E18 ni'ere~8 158 288 258 Deg.C Figure 3-8 Hyperbolic Tangent Fit of Beaver Valley Unit 1 Weld Metal Data 38

• 4 ClP V g'~I' DRESDEN UHII 2-HELD NAIERIAL{MDRZAZ)8 M 158 258 358 458 558 Deg.F 168 148 128 ox 88 68'Baseline 0 2 1.87E19 nf'cN<'~4 6.48E18 ntcte>~5 4.65E19 n/ce>~~I 128 88 I 68~8 M 188 158 288 258 388 Deg.C Test Temperature Figure 3-9 Hyperbolic Tangent Fit of Dresden Unit 2 Weld Metal Data DRESDEN UHII 3-HELD NAIERIAL (WDR3AZ)-58 58 158 2M 3M 458 De@.F 188~e 88 W>>W 9 68 48 I Baseline 0 12 2.86E19 n/'err<~14 6.15E18 n/co<~4 1.28E19 n/ere~0 6 2.71E16 n/cN~I o 0 68~I 48-188-58 58 188 Test Temperature 158 288 258 De@.C Figure 3-10 Hyperbolic Tangent Fit of Dresden Unit 3 Weld Metal Data 39 fl, 228 188 FARLEY UNIT I-WELD NATERIAL 58 158 258 358~~5 5 458 Deg.F 168 148 168 148 g~128 D~Q 188 88 M'68 I o~V R Baseline 0 U 1.65E19 n/cN~~X 2.88E19 n/ca~5.83E18 n/co~188 88 4c 58 188 158 Test Temperature 288 258 Deg.C Figure 3-11 Hyperbolic Tangent Fit of Farley Unit 1 Weld Metal Data FORT ILHOUN UNIT i-WELD NATERIAL 58 158*258 358 459 Deg.F 148 128 188 88 68 48~Baseline 0 W225 4.29E18 n/cN>~W265 S.BBEiS n/co<188 68 7 4c.28 58 188 158 288 258 Deg.C Test Temperature Figure 3-12 Hyperbolic Tangent Fit of Foit Calhoun Unit 1 Weld Metal Data 40 ih~

288 188 RENAUNEE-NELD NATERIAL 58 158 258 358 458 Deg.F 168 148 e 128~g 198 88 68 R Basel ine 0 P 2.89E19 n/cN~~RR 2.87E19 n/ca~~~U 5.S9E18 nt'cN~a 128 88~68-158-189-59 9 58 198 158 289 258 Deg.C Test Temperature Figure 3-13 Hyperbolic Tangent Fit of Kewaunee Weld Metal Data QUAD CITIES UNIT 2-MELD NATERIAL (NQC282)-58 M 158 2M 358 458 Deg.F 128 198 r-e 88 4l~0 68 48 5 Baseline 0 12 8.97E18 nf'c~~~3 2.43E19 n/'ca~R 68~I 4c 9 M 188 158 288 258 Deg.C Test Temperature Figure-3-14 Hyperbolic Tangent Fit of Quad Cities Unit 2 Weld Metal Data 41 1&A J p L 168 SOHGS UHII i-WKLII HAIERIAL 58 158 258 358 458 Deg.F 148 128 i7)188 88 68 28~0 0 0~Baseline 0 A 1.28E19 nf'cv>r F 5.14E19 n/c~~188 68, 7 4c-188-58 58 188 158 288 258 Deg.C Test Temperature Figure 3-15 Hyperbolic Tangent Fit of SONGS Unit 1 Weld Metal Data 128-58 ZII UHII 2-WELII HAIERIAL 58 158 258 458 Deg.F Pn 88 68 0%48~~~Basel ine 0 T 1.18E19 n/c~~~Ij 2.88E18 n/ca~I 48~58 188 158 288 258 Deg.C Test Temperature Figure 3-16 Hyperbolic Tangent Fit of Zion Unit 2 Weld Metal Data 42

NORMALlZED WELD USE DATA FOR l0 PLANTS I G CC Lu Z UJ I-O CL Q CC Q O LIJ N CC O 200 150 IOO 50 0 0~o Q 100 200 300 TEST TEMPERATURE (F)400 Zion 2 O SONGS 1+Quad City 2 0 Kewaunee cI Fort Calhoun I>Farley 1<3 Dresden 3 v Dresden 2<Beaver Valley 0 ANO-1 t Figure 3-17 Linear Regression Fit to Normalized Upper Shelf Weld Data 43

~5 gV'A J'P~II

4.0 Summary

and Conclusions Based on the analyses reported herein,.it has been concluded that there is a positive linear correlation between fractional decrease in USE (f)and increase in tensile yield strength (ho).The following functional form can be used to accurately predict"f", provided hadata are available:

f=0.015 d awhere f=fractional decrease in USE ho=increase in yield strength (ksi)(4-1)In cases where surveillance capsule data are available, the unirradiated USE can be estimated as follows: USEIRR U$E'-(1-f)(4-2)where USE'unirradiated USE (ft-Ibs)USE'""=irradiated USE (ft-Ibs)The uncertainty in estimating the unirradiated USE using this model was determined by applying the model to 145 LWR welds for which USE;USE'~, and badata are available.

The two sigma limit was determined to be 23.69 ft-lbs.The model was applied to the NMP-1 surveillance weld and the unirradiated USE was calculated to be 126 ff-lb.Subtracting the two sigma of 24 ft-Ib yields a lower bound estimate of 102 ft-lbs.This value is consistent with the 100 ft-Ib value obtained earlier[MA92a]using engineering judgement.

It is NMPC's position that the surveillance weld Charpy behavior is representative of the beltline weld material behavior.The beltline welds and surveillance weld were manufactured by the same suppliers, the weld wire type and flux type are the same, the welding procedure used is the same, and the Cu and Ni content of the surveillance weld is representative of the beltline welds.Therefore, based on the.analyses reported herein, the unirradiated USE for the NMP-1 beltline welds is conservatively estimated to be 102 ft-lbs.This result, which is based on an in-depth statistical analysis, is consistent with earlier estimates of 90 ft-Ibs based on engineering judgement, Therefore, as reported in Reference[MA92a], none of the NMP-1 beltline weld materials will exhibit USE levels below 50 ft-Ibs prior to EOL.44 1 ,1 C

5.0 References

[ABB92]ABB/CE (T.G.Murray)letter to Yang P.Soong, NMPC, dated November 4, 1992, Re: Nine Mile Point Unit 1 Reactor Vessel Materials".

[CE90]"Niagara Mohawk Power Corporation Nine Mile Point Unit 1 Reactor Vessel Weld Materials", Report No.'6390-MCC-001, ABB Combustion Engineering Nuclear Power Combustion Engineering, Inc., Windsor, Connecticut, June, 1990.[LE64][MA85a]Lewis, S.R., Welding Material Qualification to Requirements of NAV Ships 250-1500-1, Metallurgical R&D, Combustion Engineering, Sept.1964-Feb.1965.I Manahan, M.P.,"Procedure for the Determination of Initial RTN>>in Cases Where Limited Baseline Data are Available", November, 1985.[MA85b]Manahan, M.P., Quayle, S.F., Rosenfield, A.R., and Shetty, D.K.,"Statistical Analysis of Cleavage-Fracture Data", Invited paper, Conference" Proceedings of the International Conference and Exhibition on Fatigue, Corrosion Cracking, Fracture Mechanics, and Failure Analysis, Salt Lake City, December 2-6, 1985.[MA901[MA91][MA92a]Manahan, M.P.,"Nine Mile Point Unit 1 RT>>Determination", Final Report from MPM Research&Consulting to NMPC, September 28, 1990.Manahan, M.P.,"Nine Mile Point Unit 1 Surveillance Capsule Program", NMEL-90001, January 4, 1991.4 Manahan, M.P., Soong, Y.,"Response to NRC Generic Letter 92-01 for Nine Mile Point Unit 1", NMPC Project 03-9425, June 12, 1992.[MA92b]Manahan, M.P., Report entitled,"Upper Shelf Energy Drop Trend Curve Modelling", November 30, 1982.[MA93a]Manahan, M.P., Final Report entitled,"Elastic-Plastic Fracture Mechanics Assessment of Nine Mile Point Unit 1 Beltline Plates for Service Level A and B Loadings", February 19, 1993.[MA93b], Manahan, M.P., Final Report to NMPC,entitled,"Elastic-Plastic Fracture Mechanics Assessment of Nine Mile Point Unit 1 Beltline Plates for Service Level C and D Loadings", dated February 22, 1993.45 c>~r<

,[McFRAC]Manahan, M.P., et.al.,"Statistical Analysis Methodology for Mechanics of Fracture", Final report to Battelle's Corporate Technology Development Office, 1984.[NRC92]NRC letter to NMPC dated October 13, 1992, Re: Summary of September 30, 1992, Meeting to Discuss Licensee's Response to Generic Letter 92-01,"Reactor Vessel Structural Integrity", for Nine Mile Point Nuclear Station Unit No.1.[0D86]Odette, G.R., Lombrazo, P.M.,"Relationship Between Irradiation Hardening and Embrittlement of Pressure Vessel Steels", Proceedings of the 12th ASTM Symposium on the Effects of Irradiation on Materials,.ASTM STP 870, pp.840-860, 1986.[PREDB]PR-EDB: Power Reactor Embrittlement Data Base, Version 1, NUREG/CR-4816, Revision 1, dated May, 1991.[ST 84]Stahl, D., Manahan, M.P., Failey, M.P., Landow, M.P., Jung, R.G., and Lowry, L.M.,"Examination, Testing, and Evaluation of Irradiated Pressure Vessel Surveillance Specimens from the Nine Mile Point Nuclear Power Station", Final Report from Battelle-Columbus to NMPC, July 18, 1984.[SYSTAT]l"SYSTAT 5.03: Statistical Code Package", SYSTAT, IncCopyright 1991.46 A"j A