ML20207H794

Rev 0 to WCAP-15180, Commonwealth Edison Co Byron,Unit 2 Surveillance Program Credibility Evaluation

ML20207H794
Person / Time
Site:	Byron
Issue date:	06/30/1999
From:	Christopher Boyd, Laubham T, Trombola D WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
Shared Package
ML20207H753	List: ML20207H750 ML20207H756 ML20207H762 ML20207H767 ML20207H773 ML20207H777 ML20207H785 ML20207H794 ML20207H801 ML20207H807
References
WCAP-15180, WCAP-15180-R, WCAP-15180-R00, NUDOCS 9907210211
Download: ML20207H794 (34)

Text

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Westinghouse Non-Proprietary Class 3 1

WCAP- 15180 Revision 0 )

l Commonwealth Edison

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Company Byron Unit 2 .

Surveillance Program Credibility Evaluation  ;

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. We stingh'ou s e Ele ctr'ic C ompany LLC W

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Westinghouse Non. Proprietary Class 3

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~ Commonwealth Edison Company Byron Unit 2 .

Surveillance Program Credibility Evaluation

. Westinghouse Electr'ic Company LLC i !~

WESTINGHOUSE NON-PROPRIETARY CLASS 3 WCAP-15180 Commonwealth Edison Company Byron Unit 2 Surveillance Program Credibility Evaluation T. J. Laubham June 1999 Approved:

' C. H. Boyd, Manage'f Equipment & Materials Technology Approved: 8M[. [d M D. M. Trombola, Masfager' i

l Mechanical Systems Integration i

Westinghouse Electric Company LLC Energy Systems P.O. Box 355 Pittsburgh, PA 15230-0355 '

C1999 Westinghouse Electric Company LLC All Rights Reserved

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TABLE OF CONTENTS L i

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. LIST OF TABLES...... . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. .. . . . . . . . . . ..v PREFACE ... ... . . ... .... ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. .. .si 1 EXEClJFIVE

SUMMARY

(OR) ABSTRACT... . . .

..I 1 INTRODUCTION ... . ...... . . . ...................... . . . . . . . . .

. . . . . ....2 2 EVALUATION ........................... . . . . . . . . . . . . . ..

1 3 REFERENCES .... ... . . ..... .. . . .. . . . . . ... . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 14 i I

. . . . . . . . A-0 APPENDIX A: NRC CASES 4 & 5 FROM NOVEMBER INDUSTRY MEETING..

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iv LIST OFTABLES Table 1 Surveillance Data - Normalization for Credibility Determmation i (when all Byron data is being used) . . . , . . . . . ..4 Table 2 Credibility Assessment - Byron Unit 2 Surveillance Capsule Data Only.. . . . . .5 1 Table 3 Byron Unit 2 Vessel Weld CF Based on Byron Unit 2 Surveillance Capsule Data . . . . .. 6 Table 4 Slope of the Best Fit Line for Byron Units 1 & 2 Surveillance Capsule Weld Data.. . .7 Table 5 - Best Fit of all Weld Metal Surveillance Data Available... .....................8 Table 6 Surveillance Data - Norn=hntion for Credibility Deternunation (when all Braidwood data is being used)....... . . . . . . . . . . . . . . . . . . . . . . . .9 Table 7 ' Best Fit for Brandwood Units I and 2 Surveillance Capsule Data .. .. '. . .. . . . . . . . . 10 Table 8 Calculation of Chenustry Factor for the Lower Shell Forging using Surveillance Capsule Data . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... ....I1 Table 9 Predicted Versus Best-Estunate ARTwor Values for the Byron Unit 2 Forging Surveillance Data.... .... ... ....... ... . .... . . . . . . . . . . . . . . . . . . . . . . 12 7

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PREFACE This report has been technict.!)y reviewed and verified by: [

Reviewer:

Ed Terek '

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WCAP-15180 '

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SUMMARY

The purpose of this report is to Mi- the results 'of the surveillance program credibility evaluation gifw.4 using the results of the latest capsule testag from Byron Unit 2. Capsule X was the latest capsule removed from the Byron Unit 2 reactor vessel and the results of the testing are documented in WCAP-15176ld. De credibility evaluation herein shows all the Byron Unit 2 surveillance data to be credible. He Braidwood Units 1 aed 2 beltline weld metal (Heat # 442011) surveillance data is applicable to the Byron Unit 2 nozzle to intermedute shell girth weld and shown to be credible.

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1. INTRODUCTION Regulatory Guide 1.99, Revision 2, describes general procedures acceptable to the NRC staff for calculating the effects of neutron radiation embrittlement of the low-alloy steels currently used for light-  ;

water-cooled reactor vessels. Position C.2 of Regulatory Guide 1.99, Revision 2, describes the method for l calculating the adjusted reference temperature and Charpy upper-shelf energy of reactor vessel beltline materials using surveillance capsule data. The methods of Position C.2 can only be applied when two or more credible surveillance data sets become available from the reactor in question. Note: These criteria .

l are also given in 10'CFR 50.61-To date there has been three survedlance capsules removed from the ByTon Unit 2 reactor vessel. To use these surveillance data sets, Gey must be shown to be credible. In accordance with the discussion of RWeary Guide 1.99, Revision 2 (or 10 CFR 50.61), there are five requirements that must be met for the

surveillance data to bejudged credible.

. The purpose of this evaluation is to apply the credibility requirements of Regulatory Guide 1.99, Resision 2 (or 10 CFR 50.61), to the Byron Unit 2 reactor vessel surveillance data. The Braidwood Units 1 and 2 surveillance weld data are also evaluated for credibility, and applicability to the ByTon Unit 2 vessel weld.

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2 EVALUATION: <

i Criterion 1: Materials in the capsules should be those judged most likely to be controlling with regard to radiation embrittlement.

' The beltline region of the reactor vessel is defmed in Appendix G to 10 CFR Part 50, ." Fracture Toughness Requirements", as follows:

"the reactor vessel (shell material including welds, heat affected zones, and plates or -

forgings) that directly surrounds the effective height of the active core and adjacent regions

. of the reactor vessel that are predicted to experience sufficient neutron radiation damage to be considered in the selection of the most limiting material with regard to radiation damage."

The Byron Unit 2 reactor vessel consists of the followmg beltline region materials:

Inte..sdiate shell forging [49D329/49C297]-1-1 Lower shell forgmg [49D330/49C298]-1-1 Nozzle shell forgmg 4P-6107

'ne intermediate shell forgeg to lower shell forgmg circumferential weld seam WF-447 fabricated with weld wire heat number 442002, Linde 80, Flux Lot 8064.

De nozzle shell forging to intermediate shell forging circumferential weld seam WF-562 fabricated with weld wire heat number 442011, Lmde 80, Flux Lot 8061.

The remammg vessel forgmg and weld materials are predicted to experience less than 10" n/cm2 fluences.

The Byron Unit 2 surveillance program utilizes tan 6ential and axial test specimens from the lower shell I forging [49D330/49C298]-1-1. De surveillance weld metal was fabricated with weld wire heat number 442002., Flux Type Linde 80, I.ot Number 8064.

At the time when the surveillance program material was selected it was believed that copper and phosphorus were the elements irost important to embrittlement of reactor vessel steels and the nozzle shell was not considered a " beltline" material. De intermediate and lower dull forgings had the same initial RTmyr, while the lower shell forging had the lowest initial USE value of all forging materials in the

" beltline" region. In addition, the lower shell forging had slightly higher copper content and approximately the same phosphorous content of the other " beltline" forgmg matenals. Hence, based on one of the highest copper content and the lowest initial USE of all forgmg materials, the lower shell forging was chosen for the surveillance program Weld seam WF-447, on the other hand, was considered the only weld in the beltline region and therefore was' representative of all the beltline welds.

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3 Based on the above discussion and the methodology in use at the time the program was developed, the Byron Unit 2 surveillance material meets this criteria.

Criterion 2: Scatter in the plots of Charpy energy versus temperature for the irradiated and unirradiated conditions should be small enough to permit the deternunation of the 30 ft-lb temperature

- and upper shelf energy unambiguously. )

Plots of Charpy energy versus L.c..eare for the unirradiated and irradiated condition are presented Appendix C ofWCAP-15176 13,-

Based on engmoenngjd . the scatter in the data presented in these plots is small enough to permit the AL don of the 30 A-lb L.r..eare and the upper shelf energy of the Byron Unit 2 surveillance matenals unambiguously. Hence, the Byron Unit 2 surveillance data meets this criterion.

Criterion 3: When there are two or more sets of survedlance data from one reactor, the scatter of ARTurr 4 values about a best-fit line drawn as described in Regulatory Position 2.1 normally should be less than 28'F for welds and 17'F for base metal. Even if the fluence range is large (two or more orders of magmtude), the scatter should not exceed twice those values. Even 3 if the data fail this criterion for use in shift calculations, they may be credible for det...hh.g decrease in upper shelf energy if the upper shelf can be clearly determmed, followmg the de6mtion given in ASTM E185-82.

The fha +=1 form of the least squares method as described in Regulatory Position 2.1 will be utilized to detennine a best-fit line for this data and to AL..-.s if the scatter of these ARTum values about this line 1

' is less than 28'F for welds and less than 17'F for the plate. Followmg is the calculation of the best fit line I as described in RT'l=wy Position 2.1 of Reit=wy Guide 1.99, Revision 2.

Byron Unit 2 has two w..L. tial welds that will be evaluated for credibility. These will be evaluated j in two parts: 1.) Weld WF-447 (I L..A to Lower Shell Circ. Weld) is made from weld wire heat l 442002 and is part of both Byron Unit 1 and Byron Unit 2 surveillance program, 2.) Weld WF-562 {

- (Nozzle Shell to Intermediate Shell Cire. Weld) is made from weld wire heat 442011 and is part of l Braidwood Units I and 2 surveillance programs only. In *he first situation there is data available from

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. Byron Unit, I surveillance program for the Byron Unit 2 surveillance weld metal. In the second situation

. there is data from Braidwood Units I and 2 surveillance programs for the ByTon Unit 2 cire. weld WF-562

-. which is not ir the Byron Unit 2 surveillance program. Since the welds in question utilize data from other surveillance programs, the rew.i ;.er.dsd NRC methods for deternumng credibility will be followed. The NRC methods were presented to industry at a meetmg held by the NRC on November 12,~ 1997. At this meetmg the NRC presented five cases. Of the five cases, Case 4 and 5 most' closely represent the two situation listed above for Byron Unit 2 surveillance and non-surveillance weld materials (Case 4 goes with

- # 1 above and Case 5 with # 2 above). See Appendix A foi a copy of Cases 4 and 5 from the NRC November 1998 meeung. Note, for the forging materials, the straight forward method of Regulatory Guide 1.99, Revision 2t21 will be followed.

Froen WCAP-15124t )), the Byron Unit 1, Byron Unit 2, Braidwood Unit .I and Braidwood Unit 2 have an average inlet temiwiAre of 553*F. Therefore, no temperature adjustment is needed.

First, NRC Case 4 (Byron Situation # 1) will be evaluated for the Byron Unit 2 surveillance weld metal, "Survedlance Data Available from Plant and Other Sources".

TABLE 1

> Surveillance Data - Normalization for Credibility Deternunation (when all B3 Ton data is being used)

Capsule Cu ' Ni Irradiation Fluence Fluence Measured Temperature Ratio +

(%)- (%) Tu. w u re (x 10") _ Factor ARTa Adjusted Temperature (T%) (FF) (553'F)m Adjusted (553'F)

ARTmW U-Byron 11 0.02 0.69 553*F 0.404- 0.748 5.6'F 5.6*F 5.6'F X-Byron 1 0.02 0.69 553*F 1.57 1.124 40.l*F 40. I'F 40. l'F W-Byron 1 0.02 0.69 553'F 2.43 1.239 51.3*F 51.3*F 51.3'F U-Byron 2 0.02 0.71 553*F - 0.405 0.749 8.4*F 8.4'F 8.4'F W-Byron 2 0.02 0.71 553'F 1.27 1.067 28.9 F 28.9'F 28.9'F X-Byron 2_ 0.02 0.71 553'F 2.30 1.229 54.0*F 54.0*F 54.0*F Nors.

(1) .. No temperature adjustment required.

(2) The normahzed chemical composition for this weld heat (442002) is 0.02%Cu and 0.70%Ni. This .

produces a +- - ::Ty factor of 27, which identical to the chemistry factor for both the Byron I and 2 surveillance data. Therefore the surveillance weld metal ARTer values were not adjusted to normahze chemical composition.

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5 Assume the following for Byron Unit 2 the plant being assessed.

Weld heat number 442002 is in the surveillance program and in the vessel. and Tg.m = 553*F Surveillance data for heat 442022 is also available from other sources. The Best Estimate for heat 442002 weld metal.

0.04% Cu, 0.63% Ni > CF uw.v icu,. = 54.0*F Credibility assessment - Byron Unit 2 Data Onlv:

The data most representative for Byron Unit 2 is that from Byron Unit 2 since the irradiation emironment of the surveillance capsules and the vessel are very similar. The data require's the least adjustments.

Byron data should be exammed mdependently to determine credibility. Since all data are taken from one source (Byron Unit 2), plot measured ARTmversus FF and determine best fit line.

Slope of best fit line = 32.3*F TABLE 2 Credibility Assessment - Byron Unit 2 Surveillance Capsule Data Only Capsule Cu Ni Irradi,ation Fluence Fluence ' Measured Predicted (Measured

(%) (%) Temperature (x 109 Factor l ART m ARTm from -

(T%) (FF) Best Fit Line Predicted)

ARTmyr U-Byron 2 0.02 0.71 553*F 0.405 0.749 8.4'F 24.2*F -15.8'F W-Byron 2 0.02 0.71 553'F 1.27 1.067 28.9 F 34.5'F -5.6*F X-Byron 2 0.02 0.71 553'F 2.30 1.225 54C"F 39.6*F 14.4'F Where predicted ARTmyr = (Feopewr ) * (Fluence Factor)

Data is credible since the scatter is less than 28'F for all surveillance specimens.

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Determination of CF - Byron Unit 2 data only l

. No temperature adjustments are necessary since T,w, = Ts.m i e Adjust measure values of ARTm for chemical composition differences (normalize data to best estimate of vessel weld):

Ratio = (CFvw + CFsw)= (54.0 + 27.0) =2.0 Following is the determmation of the best fit line relating adjusted (" ratio and temperature" adjusted)

ARTer to FF. The slope of this best fit line is the CFs, % l TABLE 3 Byron Unit 2 Vessel Weld CF Based on Byron Unit 2 Surveillance Capsule Data Material Capsule Capsule f") FF*) ARTer") FF*ARTer FF 2

U 0.405 0.749 16.8 12.6 0.561 Weld Metal W l.27 1.067 57.8 61.7 1.138 X 2.30 1.225 108.0 132.3 1.50 SUM: 206.6 3.199 2

. CFw.w = I(FF

• RTer) + I( FF ) = (206.6) + (3.199) = 64.6 F Notes, (a) Calculated fluence (x 10 n/cm2 , E > 1.0 MeV).

1 (b) FF = fluence factor = fm2 .o i.% o ,

(c) The surveillance weld metal ARTwar values have been adjusted by a ratio factor of 2.0. l Since no temperature adjustments were required in this case, the ratio adjusted ARTm is the same as me

" ratio and temperature" adjusted ARTwor.

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E l 7 Cicdibility Assessment - All Data:

The data from all sources should also be considered Since data are from multiple sources the data must be adjusted for chemical composition and irradiation environment differences and then plot the " ratio and temperature" adjusted ARTa values versus FF and determine the best fit line.

For credibility determmation, data are nonnalized to the mean chemical composition and temperature of the Byron Unit 2 surveillance specimens.

TABLE 4 Slope of the Best Fil Line for Byron Units 1 & 2 Surveillance Capsule Weld Data FFN 2

Material Capsule Capsule f* Ratio FF* ART m FF Temperature Adjusted ARTmW I U (CAE) 0.404 0.748 5.6'F 4.2 0.560 Weld Metal X (CAE) 1.57 1.124 40.l'F 45.1 1.263 W(CAE) 2.43 1.239 51.3*F 63.6 1.535 U (CBE) 0.405 0.749 8.4*F 6.3 0.561 l

W(CBE) 1.27 1.067 28.9 F 30.8 1.138 X (CBE) 2.30 1.225 54.0'F 66.2 1.550 l

SUM: 216.2 6.607 2

CFw.w = I(FF

• rte) + I( FF ) = (216.2) + (6.607) = 32.7'F Notes.

2 (a) Calculated fluence (x 10" n/cm E > 1.0 MeV).

(b) FF = fluence factor = fazi.o rwo ,

(c) The surveillance weld metal ARTm values have not been adjusted (Ratio Procedure: (Ratio = 1.0 for Unit 1 & 2) and irradiation temperature is 553*F (See Table C-1)).

The slope of the best fit line = 32.7'F I

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TABLE 5 Best Fit of all Weld Metal Surveillance Data Available Capsule Cu Ni Irradiation Fluence Fluence Ratio Predicted (Measured

(%) (%) Temperature (x 109 Factor Temperature ARTer -

(T%,) (FF) Adjusted from Best Predicted)

(553*F) Fit Lme ARTer ARTer U-Byron 1 0.02 0.69 553'F 0.404 0.748 5.6'F 24.5 F -18.9 F X-Byron 1 0.02 0.69 553'F 1.57 1.124 40. I'F 36.8'F 3.3 F W-Byron 1 0.02 0.69 553*F 2.43 1.239 51.3'F 40.5'F 10.8 F U-Byron 2 0.02 0.71 553'F 0.405 0.749 8.4'F 24.5'F -16. I'F W-Byron 2 0.02 0.71 553'F 1.27 1.067 28.9 F 36.8 F -7.9'F ,

X- Byron 2 0.02 0.71 553*F 2.30 1.225 54.0 F 40.5 F 13.5*{

Where predicted ARTmr = (Slopewa) * (Fluence Factor) {

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Data is credible since the scatter is less than 28 F for all surveillance specimens.

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. Now, the NRC Case 5 (Byron Situation # 2) will be evaluated for the Byron Unit 2 non surveillance weld meta; (WF-562, Heat 442011), " Surveillance Data NOT Available from Plant but Available from Other

. Sources".

TABLE 6W Surveillance Data - Normalization for Credibility Determmation (when all Braidwood data is being used)

Capsule Cu .. Ni : Irradiation . Fluence Fluence Measured Temperature Ratio

(%) (%) Temperature (x 109 Factor ART m Adjusted Temperature (T%) (FF) (553 F)* Adjusted (553*F)

ARTmW U-Bmid.1 0.03 0.67 553'F 0.3814 0.733 10*F 10*F .10*F X-Braid 1 0.03 0.67 553*F 1.144 1.038 25'F 25'F 25'F U-Braid. 2 0.03 0.71' 553*F 0.3933 0.741 0'F O'F O'F X-Braid. 2 0.03 0.71 553*F 1.126 1.033 20*F 20'F 20*F Notes.

(1) All data was obtamed from WCAP-14824 Rev. 2W.

(2) 'Ihe Braidwood Units I and 2 measured ARTm alues v were not required to be reduced due to operatmg L.cie. ires since the i .pieures are identical (i.e. T = 553'F).

(3) The normalized chemical composition for this weld heat (442011) is 0.03%Cu and 0.69%Ni. This produces a chemistry factor of 41, which identical to the chemistry factor for both the Braidwood I and 2 surveillance datac Therefore the surveillance weld metal ARTm values were not adjusted to normalize chemical composition.-

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' Assume the followmg for Byron Unit 2 the plant being assessed.

i Weld heat number 442011 is Not in the surveillance program and in the vessel, I and Tg. = 553'F l Surveillance data for heat 442011 is ONLY available from other sources. The Best Estimate for heat

'442022 weld metal  !

i 0.03% Cu, 0.67% Ni > CF w ,wew = 41.0*F F ..

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10 Credibility assessment - Braidwood Unit 1 & 2 All Data:

Note: At this point in the NRC Case 5, it is judged that one of two sets of data, from other plants. is closer related to the plant being evaluated, then that data is checked for credibility indisidually. The step after this states "Ifit had been determined that all data were applicable to Plant 'Y', credibility and the CF would have been evaluated as follows:"

Braidwood I and 2 have identical operating temperatures and are the same as the ByTon 2 operatmg temperature, therefore checking one Braidwood individually for credibility is not applicable in this case and both units should be considered simultaneously.

Since it has been detemuned that Braidwood Unit I and 2 data are both applicable to ByTon Unit 2, ,

therefore credibility and the CF will be evaluated as follows: l 1

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l Credibility Determmation - All Data: l Plot " ratio and temperature" adjusted ARTer values (normalized to the mean chemical composition and temperature of the surveillance specimens) versus Fluence Factor for all data (Not just 8.sidwood I or Braidwood 2 individually) and detemune best fit line Slope of best fit line = 16.7'F TABLE 7 Best Fit for Braidwood Units 1 and 2 Surveillance Capsule Data i

Capsule Cu Ni Irradiation Fluence Fluence Ratio Predicted (Ratio +

(%) (%) Temperature (x 10") Factor Temperature ART m Temperature (T%) (FF) Adjusted from Best Adjusted -

(553*F) Fit Line Predicted)

ARTer ART m U-Braid.1 0.03 0.67 553'F- 0.3814 0.733 10'F 12.2*F -2.2 F X-Braid.1 0.03 0.67 553'F 1.144 1.038 25'F 17.3'F 7.7'F U-Braid. 2 0.03 0.71 553*F 0.3933 0.741 0*F 12.4'F -12.4*F X-Braid. 2 0.03 0.71 553'F 1.126 1.033 20'F 17.3'F 2.7'F Where predicted ARTm = (Slopewra) * (Fluence Factor)

Data is credible since the scatter is less than 28'F for all surveillance specimens.

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11 Now that the Weld Metal has been evaluated for credibility, the Forging material must be evaluated. Table 8 calculates the CF from surveillance data for the lower shell forging 49D330/49C298-1-1.

TABLE 8 Calculation of Chemistry Factor for the Lower Shell Forging using Surveillance Capsule Data 1 Material Capsule Capsule (* FF ARTm" FF*ARTm FF' Lower Shell Forging U 0.405 0.749 0.0'd' O 0.561

[49D330/49C298]-1-1 W l.27 1.067 3.65 3.89 1.138 (Tangential) X 2.30 1.225 15.75 19.29 1.500 Lower Shell U 0.405 0.749 19.76 14.80 0.561 Forging [49D330/ W 1.27 1.067 31.88 34.02 1.138  ;

i 49C293]-1-1 X 2.30 1.225 38.91 47.66 1.500 j SUM: 119.66 6.398 CFr , = I(FF

• RTmn) + Z( FF ) 2= (119.66) + (6.398) = 18.7'F Notes.

(a) Byron Unit 2 capsule fluences were updated as a part of the capsule X dosimetry analysis results j (Ref.1), (x 10 n/cm 2, E > 1.0 MeV).

I (b) FF = fluence factor = fa2s.ai w o ,  ;

(c) ARTmn values are the measund 30 ft-lb shiR values taken from Ref.1.

(d) Actual value of ARTmn is -3.8. 'Ihis physically should not occur, therefore for conservatism (i.e. higher chemistry factor) a value of zero will be used.

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12 TABLE 9 Predicted Versus Best-Estimate ARTer Values for the Byron Unit 2 Forging Suneillance Data l

Material Capsule CF FF Best Estimate Measured Change in ARTer )

ARTer ARTer (B.E. - Measured)

Lower Shell Forging U 18.7 F 0.749 14.0'F 0F 14.0

[49D330/49C298]-1-1 W 18.7'F 1.067 20.0 F 3.7 F 16.3  !

(Tangential) X 18.7'F 1.225 22.9 F 15.8 F 7.1 I Lower Shell Forging U 18.7'F 0.749 14.0 F 19.8 F -5.8

[49D330/49C298]-1-1 W 18.7'F 1.067 20.0 F 31.9'F -11.9 l

(Axial) X 18.7'F 1.225 22.9 F 38.9*F -16.0 l

From Table 8 above, the Byron Unit 2 Forging Data has all six data points within the 17*F scatter band.

Therefore, the forging surveillance data is considered credible. '

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13 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.

He capsule specimens are located in the reactor between the core barrel and the vessel wall and are positioned opposite the center of the core. He test capsules are in baskets attached to the neutron pads.

The location of the specimens with respect to the reactor vessel beltline provides assurance that the reactor vessel w ' all and the specimens experience equivalent operating conditions such that the temperatures will not differ by more than 25*F. Hence, this criteria is met.

Criterion 5: De surveillance data for the correlation monitor material in the capsule should fall within the scatter band of the data base for that material.

He Byron Unit 2 surveillance program does not conts correlation monitor material. Herefore, this criterion is not applicable to the Byron Unit 2 surveillance program CONCLUSION: .

Based on the precedmg responses to all five criteria of Regulatory Guide 1.99, Revision 2, Section B and

- 10 CFR 50.61, the Byron Unit 2 survedlance data is credible. In addition, the Braidwood Unit I and 2 i weld data is credible and applicable to the Byron Unit 2 nozzle to intermediate shell circumferential weld l seam WF-562 (Heat # 442011).

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3 (REFERENCES

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l - WCAP-15176, " Analysis of Capsule X from the Commonwealth Edison Co. Byron Unit 2 Reactor

. Vessel Radiation Surveillance Program", T. J. Laubham, et al., March 1999.

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2 Regulatory Guide 1.99, Revision 2, " Radiation Embrittlement of Reactor Vessel Materials", U.S.

Nuclear Regulatory Commission, May,1988.

l 3 WCAP-15124, " Byron Unit 1 Heatup and Cooldown Limit Curves for Normal Operation". T.J.

L Laubham, November 1998 i

4 WCAP-14824, Revision 2, " Byron Unit 1 Heatup and Cooldown Limit Curves for Normal Operation and Surveillance Weld Metal lategration For Byron and Braidwood", T. J. Laubham, et al., November 1997.

5 WCAP-15178, " Byron Unit 2 Heatup and Cooldown Limit Curves for Nonnal Operation", T.J.

Laubham, March 1999. l l

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l APPENDIXA NRC CASES 4 & 5 FROM NOVEMBER INDUSTRY MEETING l

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- Appendix A

RA* A CASE 4 - SURVEILLANCE DATA AVAILABLE FROM PLANT AND OTHER SOURCES Surveillance data Capsule NSSS Cu Ni irradiation Fluence Fluence Measured Temperature Ratso, Designation Vendor Temperature (x10") Factor ART., Adjusted Temperature (Tw) (FF) (550'F) Adjusted ART , (550'F)

ART., . .

Plant a - 1 B&W 0.37 0.70 556.0 0.779 0.930 214.0 220.0 1 96.0 Plant b 1 B&W ~0.3F 0.67 556.0 0.107 0.431 124.0 130.0 126.0 Plant b - 2 B&W 3.31 0.67 556.0 0.864 0.960 203.0 209.0 2025 Plant c - 1 B&W [O 33 0.67 556.0 0.830 0.948 182.0 188.0 182.2 Plant c - 2 B&W l 0.21 0.67 556.0 0.968 0.991 222.0 228.0 2210 Plant x - 1 West. 0.24 0.44 836.0 0.281 0.653 145.0 151.0 1721 Plant x - 2 West. l 0.24 0.661 536.0 1.940 1.181 240.0 226.0 257.5!

Normalization for credibilltv determination (when all data are being used)

Data normalized to mean chemical composition (i.e., copper and nickel) of surveillance specimens -

Cu = 0 31%

Ni = 0.67%  :

l Data normalized to mean temperature of surveillance specimens T = 550*F Appendix A

CASE 4 - SURVEILLANCE DATA AVAILABLE FROM PLANT AND OTHER SOURCES (cont'd)

Assume the following for Plant "x" (the plant whose vessel is being assessed)

Weld heat 299L44 is in the surveillance program and in the vessel  !

k T,, = 536 *F Surveillance data for heat 299L44 is also available from other sources Best estimate for heat i

Wald metal 0.34% Cu, 0.68% Ni - CFy,,,, y,,,,, e,,,,. = 220.6 'F Credibility assessment - Plant "x" data only The data most representative for Plant "x" is that from Plant "x" since the irradiation environment of the surveillance capsules and the vessel are very similar. This data requires the least adjustment (e.g., no temperature correction)

Plant "x" data should be examined independently to determine credibility. .

Since all data are from one source (Plant "x"), plot measured ARTum versus FF and determine best fit line Slope of best fit line = 214.8'F Capsule Cu Ni irradiation Fluence Fluence Measured Predicted (Measured -

Temperature (x10") Factor ARTm ARTm frorn Predicted)

(T w ) (FF) best fit line ART ,

Plant x .1 0.24 0.66 536.0 0.281 0.653 165.0 140.3 24.7 Plant x 2 0.24 0.66 534.0 1.940 1.181 240.0 253.6 -13.6 where predicted ART =(slope ,7(Fluence Factor)

Data are credible since scatter is less than 28'F for all surveillance specimens Appendix A

A-3 CASE 4 - SURVEILLANCE DATA AVAILABLE FROM PLANT AND OTHER SOURCES (cont'd) l Determination of CF - Plant "x" data only No temperature adjustments are necessary since c T ., = T,..

Adjust measured values of ARTuor for chemical composition differences as follows (nonnalize data to best estimate of vessel being assessed):

1 Ratio Adjusted ART,,7 - ( "'****. ~~' c*~ ; . AR T Ts&de. Serv. Chem.

l CFr.u,,m. m = 182.9'F Determine best fit line relating adjusted (" ratio and temperature" adjusted) ARTsarr to FF. The slope of this best fit line is the CF.,,, o, .

Since no temperature adjustments were required in this case the ratio adjusted ARTuor is the same as the " ratio and temperature" adjusted ART,or CFw. m = 259.0*F Appendix A

u CASE 4 - SURVEILLANCE DATA AVAILABLE FROM ,

PLANT AND OTHER SOURCES (cont'd)

Credibility assessment - All data The data from all sources should also be considered Since data are from multiple sources, must adjust data for chemical  !

compositior: and irradiation environment differences and then plot the

" ratio and temperature" adjusted ARTm values versus FF and determine best fit line For credibility determination, data are normalized to the mean chemical composition and temperature of the surveillance specimens Slope of best fit line = 218.4*F Capsule Cu Ni irradiation Fluence Fluence Ratio and Predicted (Adjustee .

Tempeenture (x10") Factor Temperature ARTc from Predected)

(T ,,,) (FF) (550) best fit line ART ,

Adjusted ART.

Plant a 1 0.37 0.70 556.0 0.779 0.930 195.0 203.1 7.1 Plant b .1 0.33 0.87 558.0 0.107 0.431 126.0 94.1 31.9 Plant b 2 0.33 0.87 554.0 0.884 0.960 202.5 209.6 7.1 Plant c .1 0.33 0.57 558.0 0.830 0.948 182.2 207.0 24.8 Plant c . 2 0.33 0.D 558.0 0.968 0.991 221.0 216.4 4.5 Plant x .1 0.24 0.88 536.0 0.281 0.853 172.1 142.8 29.4 Plant x 2 0.24 0.86 534.0 1.940 1.181 257.6 258.0 -0.4 where predicted ARTe = (slope .y(Fluence Factor)

Data are not credible since scatter is greater than 28'F for several surveillance specimens Appendix A

A-5 CASE 4 - SURVEILLANCE DATA AVAILABLE FROM PLANT AND OTHER SOURCES (cont'd)

Determination of CF - All Data if data were credible, the CF would be determined as follows Must make irradiation temperature and chemical composition adjustments since the irradiation temperature and chemistry differ between the capsules and the plant being assessed For capsules with T% greater than 536*F (i.e., Tm ),

must increase ARTuor, by 1.0*F for each degree difference in irradiation temperature to get the temperature adjusted ARTuoy (i.e., ARTuor,7%)

To obtain the " ratio and temperature" adjusted ARTuor, apply the ratio procedure as follows:

Ratiotremperature Adjusted ART,,7 = ( C F'**" '****' '*** * ) AR T,,7 , ,,,,,,,

Tehk Sm. Chem.

Determine best fit line relating adjusted (" ratio and temperature" adjusted) ARTuor to FF. The slope of this best fit line is the CFw,m. CFm, m = 247.",*F Appropriate CF Data from the plant being assessed were evaluated and the data were credible When all of the data were evaluated, the data were determined to be not credible Since the data from the plant being assessed is the most appropriate and requires the least amount of adjustment, the CF determined from evaluation of the Plant "x" data is the most appropriate.

CF m .= 259.0*F Appendix A

L 1 CASE 4 - SURVEILLANCE DATA AVAILABLE FROM PLANT AND OTHER SOURCES (cont'd)

Effects of data analysis technique (Ratio procedure and using plant-specific data) .

Previous analyses Ratio procedure not applied, temperature correction to data from other sources not made, All data used RTuortu) = -7.0 *F; M = 49.8; CF = 217.0 *F; FF = 0.8745 i RTuor, = -7.0 + 49.8 + (217.0

• 0.8745) = 232.6'F Current analyses Ratio procedure applied, No temperature correction necessary, Only Plant "x" data used RTuor, = -7.0 + 49.8 + (259.0

• 0.8745) = 269.2 *F l

l Appendix A

\_

N/

CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES Surveillance data Capsule NSSS Cu Ni irradiation Fluence Fluence Measured Temperature Ratio, Designation Vendor Temperature (x10") Factor ART. Adjusted Temperature (Tw) (FF) (547'F) Adjusted ART , (547'F)

ART.

Plant a .1 West. 0.23 0.82 442.0 0.502 0.808 110.0 105.0 104.0 Plant a - 2 West. 0.23< -0.42 7542.0 0.829 0.947 165.0 160.0 158.4 Plant a - 3 West. 0.23 0.82 542.0 2.380 1.234 165.0 160.0 158.4 Plant a 4 West. 0.23 0.82 542.0 2.420 1.238 180.0 175.0 173.3 j Plant b .1 B&W 0.22 0.58 556.0 0.510 0.812 148.0 187.0 163.4 l Plant b - 2 B&W- 0.22 0.58 556.0 1.870 1.141 168.0 177.0 184.2 Normalization for credibility determination (when all data are being used)

Data normalized to mean chemical composition (i.e., copper and nickel) of surveillance specimens Cu = 0.23%

Ni = 0.61%

Data normalized to mean temperature of surveillance specimens T% = 54PF Appendix A

A -b CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES (cont'd)

Assume the following for Plant "y" (the plant whose vessel is being assessed)

Westinghouse is NSSS vendor Weld heat 72445 is not in the surveillance program but is in the vessel T% = 536*F Surveillance data for heat 72445 are only avalicble from other sources Best estimate for heat Weld metal 0.22% Cu, 0.58% Ni - CF1 ,u,, vu en,. = 164.0 *F Credibility assessment - Plant "a" data only l if the irradiation environment for Plant "a" is judged to be closer to  !

Plant "y" than Plant "b", the Plant "a" data should be used in assessing the integrity of the vessel Magnitude of temperature adjustment is lower for Plant "a" than i

Plant "b", and the data are from the same NSSS vendor I Since all data are from one source, perform credibility analysis similar to Case 1 (i.e., determine best fit line through measured ART uo r values)

Appendix A

1 CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES (cont'd)

Credibility assessment - Plant "a" data only (cont'd) l Slope of best fit line = 145.8 Capsule Cu Ni irradiation Fluence Fluence Measured Predicted (Measured -

Temperature (x10") Factor ART. ART from Predicted)

(T w ) (FF) best fit line ARTov j Plant a - 1 0.23 0.82 542.0 0.502 0.808 110.0 117.8 7.8 Plant a - 2 0.23 0.42 542.0 0.829 0.947 165.0 138.2 26.8 Plant a - 3 0.23 0.82 642.0 2.380 1.234 145.0 179.9 14.1 Piant a -4 0.23 0.s2 s42.0 2.420 1.238 180.0 180.s 0.s where predicted ARTe = (W- .)*(Fluence Factor)

Data are credible since scatter is less than 28'F for all surveillance specimens Determination of CF - Plant "a" data only Must make irradiation temperature and chernical composition adjustments since the irradiation temperature and chemiste differ between the capsules and the plant being asses, sed For capsules with Tw greater than 536*F (i.e., T,..), must increase ART,,,r,,,,,,,,,,,, by 1.0*F for each degree difference in irradiation temperature to get the temperature adjusted ART,,or (i.e., ART,a,r,y%)

To obtain the " ratio and temperature" adjusted ART,,or, apply the ratio procedure as follows:

RatiolTemperature Adjusted bMT,,7 = (

• A R T ,,7, CF'**"* '****'

resu. sm. chem. '****) , ,,,,,,,,

Appendix A

M* AU CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES (cont'd)

Determination of CF - Plant "a" data only (cont'd)

Surveillance data showing irradiation environment and chemical composition adjustments - normalized to best estimate of vessel Capsule Nsss Cu Ni irradiation Fluence Fluence Measured Temperature Ratio, Designation Vendor Temperature (x10") Factor ART. Adjusted Temperature (T Q (FF) (536'F) Adjusted ART. ART.

Plant a - 1 West. 0.23 0.42 542.0 0.602 0.808 110.0 116.0 110.3 Plant a - 2 West. 0.23 0.62 542.0 0.829 0.947 165.0 171.0 162.7 Plant a - 3 West. 0.23 0.82 642.0 2.340 1.234 165.0 171.0 182.7 Piant a -4 West. 0.23 0.62 542.0 2.420 1.238 180.0 186.0 176.9 Determine best fit line relating adjusted (" ratio and temperature" adjusted) ART,.y to FF. The slope of this best fit line is the CF.,,,o.,

CF. m = 144.0*F 4

Appendix A

A-11 CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES (cont'd)

If it had been determined that all data were applicable to Plant "y", credibility l and the CF would have been evaluated as follows:

Credibility Determination - All data Plot " ratio and temperature" adjusted ARTuor values (normalized {

to the mean chemical composition and temperature of the j surveillance specimens) versus FF for all data (noi lust  !

Plant "a") and determine best fit line )

Slope of best fit line = 150.3*F ,

i Capsule Cu Ni irradiation Fluence Fluence Ratio, Predicted (Measured .

Temperature (x10") Factor Temperature ART from Adjusted) ,

(T Q (FF) Adjusted best fit line ART. i ART.

Plant a .1 0.23 0.82 542.0 0.502 0.808 104.0 121.4 -17.4 Plant a - 2 0.23 0 82 542.0 0.829 0.947 188.4 142.4 16.0 Plant a .3 0.23 0.82 542.0 2.380 1.234 158.4 186.4 27.0 Plant a 4 0.23 0.82 542.0 2.420 1.238 173.3 186.1 12.8 )

Plant b .1 0.22 0.58 556.0 0.510 0.812 183.4 122.1 J1.3 Plant b - 2 0.22 0.58 554.0 1.870 1.141 184.2 171.5 12.7 Even though only 5 of the 6 data points are credible (i.e., the scatter is less than 28'F), the data set was considered credible Determination of CF - All data Must normalize data to best estimate chemical composition and temperature of vessel being assessed and determine best fit line through the " ratio and temperature" adjusted ARTuor values as a function of FF 1

CFm, m = 154.4*F Appendix A

AN-l\4 CASE 5 - SURVEILLANCE DATA NOT AVAILABLE FROM PLANT BUT AVAILABLE FROM OTHER SOURCES (cont'd)

Effects of data analyses technique (Ratio procedure, use of similar data, use of alldata)

Previous analyses Ratio procedure not applied, Temperature correction to data from other sources not made, All data evaluated RTam = -5.0*F; M = 48.3; CF = 149.2*F; FF = 1.354 RT ,, = -5.0 + 48.3 + (149.2

• 1.354) = 245.3*F Current analyses - Using only Plant "a" data Ratio procedure applied and temperature correction made RTm, = -5.0 + 48.3 + (144.0

• 1.354) = 238.3*F Current analyses - Using all data Ratio procedure applied and temperature correction made RT , = -5.0 + 48.3 + (154.4

• 1.354) = 252.4*F 1

Conclusion:

CF determined from Plant "a" data is the most appropriate i

Least amount of adjustments to data - same NSSS vendor Environment at Plant "a" is closer to plant being assessed 1 (Plant "y") l Appendix A

Attachment I Byron Station WCAP-15124, Rev. 0, Byron Unit 1 Heatup and Cooldown Limit Curves for Normal Operation" P:WebystreW90095 doc

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