ML20070A012

Responds to Open Issues Re GL-92-01,rev 1, Reactor Vessel Structural Integrity.

ML20070A012
Person / Time
Site:	Farley
Issue date:	06/21/1994
From:	Woodard J SOUTHERN NUCLEAR OPERATING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-92-01, GL-92-1, TAC-M83461, TAC-M83462, NUDOCS 9406280120
Download: ML20070A012 (11)

Text

, , Southern Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201 Telephone (205) 868-5066 L k J. o. Woodard Executive Vice President Southern Nudear Operating Company the southem elecinc System June 21, 1994 10 CFR 50.54(f)

Docket Nos. 50-348 50-364 TAC Nos. 83461 83462 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Joseph M. Farley Nuclear Plant Responses to Open Issues Regarding Generic Letter 92-01, Revision 1 Reactor Vessel Structural Integrity Gentlemen:

On March 6,1992, the NRC issued Generic Letter (GL) 92-01, Revision 1, " Reactor Vessel Structural Integrity." The purpose of the GL was to obtain information needed to assess compliance with requirements and commitments regarding reactor vessel integrity due to events associated with the Yankee Nuclear Power Station. Southern Nuclear Operating Company (SNC) provided a response to GL 92-01, Revision 1, by letter dated July 1,1992. On October 7,1993, the NRC issued SNC a request for additional information (RAI) in order to complete the review of the SNC response to GL 92-01, Revision 1. SNC provided a response to the RAI by letter dated November 23,1993.

The NRC notified SNC, by letter dated May 20,1994, of two open issues regarding GL 92-01 and requested verification of the NRC summary data file information for Farley Nuclear Plant.

Attachment 1 provides SNC's responses to the open items identified by the NRC associated with GL 92-01, Revision 1. Attachment 2 provides the data used to determine a statistical value for the unirradiated upper shelf energy for type B4 weld filler material.

Attachment 3 provides a marked-up copy of the summary data file for the Farley Unit 1 and Unit 2 vessels to reflect changes to the information with references supporting each change.

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U. S. Nuclear Regulatory Commission Page 2 As stated in previous submittals regarding GL 92-01, Revision 1, SNC continues to comply with the requirements of 10 CFR 50.61 and 10 CFR 50, Appendix G.

If there are any questions, please advise.

Respectfully submitted, SOUTHERN NUCLEAR OPERATING COMPANY

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'oodard SWORN TO AND SUBSCRIBED BEFORE ME THIS dek)AY OF b ,1994 ht& LA L0ne-Notary'Public (/

My Commission Expires: 7/dua. /, /997 DRC; cit 920lRAl2. doc Attachments cc: Mr. S. D. Ebneter Mr. B. L Siegel Mr. T. M. Ross i

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ATTACIIMENT 1 SNC RESPONSES TO GL 92-01, REVISION 1, OPEN ISSUES ,

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The first open issue identified for Farley was associated with weld wire heats 33 A277,6329637, and 90099 in Unit 1, and weld wire heats 5P5622 and 83640 for Unit 2. Specifically, the NRC staff stated that the nickel content for these heats was determined as mean values from the Westinghouse Owners Group (WOG) database and requested that SNC provide the WOG data that was used to determine the amount of nickel. Additionally, SNC was requested by the stafTto determine the best-estimate amount of nickel in accordance with the PTS Rule,10 CFR 50.61.

SNC Response to Open Issue (1)

SNC stated in our response to NRC Request for Additional Information (RAI) regarding GL 92-01, Revision 1, dated November 23,1993, that the nickel content for beltline welds was taken from earlier WOG programs. Specifically, the 0.20% value was determined from a 1982 program performed to calculate operating and near term operating limit vessel RTndt values and the 0.21%

value was detennined from a program to develop a materials database aimed at filling in gaps where data was not available. As stated in our response to the RAI, the nickel content of the

• beltline welds is not available from the material certifications and the values listed are based on engineeringjudgement. However, a footnote to Table 2 and Table 8 of the RAI response  ;

identified these nickel values as mean values taken from the WOG materials database.

Subsequent conversations with Westinghouse have verified that the WOG database value for nickel content of the beltline welds is based solely on engineering judgement described below and not actual material certifications.

The rationale used to determine the WOG database nickel value for weld wire heats 33 A277, 6329637, 90099, 5P5622, and 83640 in the vessel beltline welds considered that both the Farley Unit I and Unit 2 vessels were fabricated between 1971 and 1973 by Combustion Engineering (CE)in Chattanooga, Tennessee. The vessels were fabricated using the automatic submerged arc  ;

welding (SAW) process and type B4 weld filler material supplied by the Reid Avery Company.

Nickel was not added as an alloying element to the B4 weld filler material manufactured by the Reid Avery Company; therefore, CE did not require the Reid Avery Company to perfonn or submit a chemical analysis value for tickel in type B4 weld filler wire. A chemical analysis of the Farley Unit I surveillance weld ma;erial, heat number 33 A277, indicated a nickel content of 0.19 weight percent, consistent with the estimated value of 0.20 weight percent reported in our response to the RAI.

SNC is a charter member of the Combustion Engineering Reactor Vessel Group (CERVG) and joined the group with the expectation of obtaining additional information to augment existing vessel chemistry and toughness data for SNC vessels. Based on reviews performed to date, SNC does not expect the nickel content of weld wire heats 33 A277,6329637, 90099, SP5622, and 83640 to exceed 0.20 weight percent. The CERVG effort is currently targeted for completion by December 1994.

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Open Issue (2)

The second open issue for Farley involved a NRC staff concern that surveillance data was used to determine the unirradiated upper shelf energy (USE) values for weld wire heat numbers 6? 29637, i 90099, SP5622,83640, and HODA. The staffs letter stated that since the surveillance data are  !

from a different heat, a statistical analysis addressing heat variability may be appropriate and that when the unirradiated USE for a particular heat of material has not been determined, the USE can be set equal to the lower tolerance limit calculated for the group of similar materials. The staff stated that the unirradiated USE should be determined such that there exists 95% confidence that ,

at least 95% of the population is greater than the !ower tolerance limit and if the lower tolerance limit results in a projected USE at EOL orless than 50 fl-lb, then SNC must demonstrate, in accordance with Appendix G,10 CFR Part 50, that equivalent lower values of USE will provide margins of safety against fracture equivalent to those required by Appendix G of Section III of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code.

SNC Response to Open Issue (2)

A statistical analysis was performed by Westinghouse, in accordance with the NRC staffs guidance, to determine a generic unirradiated USE applicable to heats 6329637,90099, SP5622, and 83640. Attachment 2 provides 61 values of Charpy V-notch energy at 100% shear where data for full Charpy curves are available for type B4 weld wire. The lower tolerance limit determined from the data in Attachment 2 resulted in a generic unirradiated USE value of 82.5 ft-Ib. For weld wire heat number 90099, Farley will utilize the generic unirradi ated USE value of 82.5 fl-lb determined by the statistical analysis. Use of the generic unirradiated USE value for heat 6329637 would result in a projected EOL USE less than 50 fl-lb. However, for heat 6329637 the Farley specific Charpy value at +10 F is known and can be used as a conservative estimate for the unirradiated USE since the unirradiated USE is known to be higher than the

+10 F Charpy value. The known Farley specific +10 F Charpy values are also being used for heats SP5622 and 83640. Since the statistical analysis is only applicable to type B4 weld wire, the

+10 F Charpy value is also being used for the SMAW filler metal, heat HODA.

Based on the above information, the projected EOL USE for the Farley Unit I and 2 belthne welds exceeds 50 fl-lb, as shown in Attachment 3; therefore, Farley Units 1 and 2 will continue to comply with the requirements of Appendix G of 10 CFR Part 50.

Attachment 1 Page 2 of 2 l

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ATTACIIMENT 2 Charpy V-Notch Energy (fl-lb) Data at 100% Shear for Determination of Generic Unirradiated USE for Welds with Type B4 Weld Filler Wire 138 159 151 152 159 174 156 150 151 162.5 144 154 139 140 149 153 135 140 141 144 154 158 135 144 145 143 143 144 122 122 l 127 125 125 125 125 172 154 162 158 87 90.5 84.5 109 116 108 126 121 99 118 129 123 113 119 86 88 82 90 94 99 100 102 Number of Points = 61 Sample Mean = 130.467 Sample Deviation = 24.4896 Lower Tolerance Bound = 82.5

ATTACHhiENT 3 h1ARKED-UP SUhihiARY DATA FILE FOR FARLEY UNITS 1 & 2 VESSELS The NRC stafTrequested that SNC verify the summary data file information contained in Enclosures 1,2, and 3 of the NRC's hiay 20,1993, letter. Accordingly, SNC provides the following marked-up copics of the summary data file with reference information to support the changes.

Sumary File for Pressurized Thermal Shock P la.itt Betttlne Meet No. 10 Neut. IRT. Method of Chemistry Method of %Cu %Ni kame Ident. Ident. Fluence et Detersin. Factor Determin.

EOL/EFPY 1 R T, CF F2rtey 1 Int. Shett C6294 1 3.75E19 0*F MTEB 5 2 91 febte 0.13 0.60 86903 2 EOL: Int. Shett C6308 2 3.75E19 10'F MTEB 5 2 82.2 Table 0.12 0.56 6/25/2017 86903 3 Lower C6940 1 3.75E19 15'F MTER 5 2 88.831 Calculated 0.14 0.55 j Shett B6919 1 l j

Lower C6897 2 3. 75E19 5'F MTEs 5-2 98.2 Table 0.14 0.56 shelt 86919 2 Int. Shett 33A277 1.24E19 56'F Generic 78.689 Calculated 0.25

• 0.21 Axial Welds Cire. Weld 6329637 3.75E19 56'F Generic -443-Table -4430. W 0.20 '

tower 90099 1.24E19 -56*F Generic 92 Table 0.17 0.20 '

Sheit Axlet Welds REFEREhCES FOR FARLEY 1:

Fluence, IRT and chemistry values f rom hovember 23, 1993, letter from D. Morey (suoC) to UskRC Docet Control Desk, select: Responses to Regaeste for Additionet Information Regarding GL 92-01.

j (0 Tbc vnnr ked- up circ.. weld % Cu ei o.zz5 a 'd cW misby &clor i

ed 114.5 ( n om Table) were de valoc s submitied b y h e_ l l

tlovem be r 23, 1993 \ceer refe r en ce d nbov e. ,

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is an esW M e d value- beed on eg oe er ing

' Chemical composition -from mean ;;lue of L'OC dat. #ddition:1 "forn tier rem. ired. jg ,,,g, g% g, 4e q , ,, , , , ; pa$,,,a is A c>riib e ) in A h ch ,er+ 1.

Summary File for Pressurized Thermal Shock 1

. l Pitnt BettlIne Heat No. 1D Neut. I R T. Method of Chemistry Method of %Cu Emi Name Ident. Ident. Fluence at Detersin. Factor Determin. {

E0L/EFPT IR T. CF '

Farley 2 Int. shett C6309 2 3.8E19 15*7 Plant 100 Table 0.14 0.60 87203 1 Specific EOL: Int. Shett C7466-1 3.8E19 10'F Plant 145.0 Calculated 0.20 0.60 3/31/2021 e7212 1 specific Lower C6888 2 3.8E19 18'F Plant 89.8 Table 0.13 0.56 shett Specific 87210-1 Lower C6293 1 3.8E19 10'F Plant 98.7 fable 0.14 0.57

$helt Specific 87210-2 Cire. Weld 5P5622 3.8E19 -40*F Plant 76 fable 0.13 0.20

• 11-923 specific Lower 83640 1.23E19 -70'F Plant 49 Table 0.05 0.20 '

Shett Specific Axlet Welds 20 923 A/S Int, shett H00A 1.23E19 -56*F Generic 10.01 Cateutated 0.02 0.%

Axial $ MAW Welds 19 923A Int. Shell BOLA 1.23E19 -60'F Plant 10.01 Calculated 0.02 0.93 Axist SMAW Specific Welds 19 9238 REFERENCES FOR FARLET 2:

Fluence, IRT , and chemistry values from Novenber 23, 1993, letter from D. Morey (SNOC) to USNRC Doctament Control Desk, s@ ject: Responses to Requests for Additional Information Regarding 92-01.

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13 an es wah d vale basr A en engineer-in3

, Chemical composition from meanwalue-of-WOG data . Additional

-informa t i c" required-to--confirm v a l u e -

pdcmed.

3 ~n c bd3 for A eng.ncericg y d3cment is Jc w a cJ i,. Att.stbnen+ 1

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Sumary File for Upper Shelf Energy Plant Name Settline Neat No. Material 1/4T USE 1/4T unirred. Method of  !

Ident. Type at Neutron USE Deternin. i EOL/EFPY Fluence at Unfrred. l EOL/EFPY USE Farley 1 Int. SheLL C6294 1 A 5338 1 73 2.34E19 99 65%

B6903 2 EOL: Int. Shell C6308 2 A 5338-1 65 2.34E19 87 651 6/25/2017 B6903-3 Lower C6940 1 A 5338 1 - 2.34E19 86 65%

shall 86919-1 g N Lower C6897 2 A 5338 1 62 2.34E19 86 65%

shott 86919 2 Int. Shett 33A2TT Linde 115 7.73E18 149 surv.

Axlet 1092, SAW Weld Welds Cire. Weld 6329637 Linde 2.34E19 # 5;!r. t: +10*F (1) 0091, SAW -44585- '*+)  !=- ^'IY 104 '*I mid value.

Lower 90099 Linde # 7.73E18 # E;!- t: Stati,+l cal Shell 0091, SAW (3)

Axist 58 82. 5(3) h gg sis y

Welds References for Farley i Fluence, heet ruber and (AJ$E vetues f rom November 23, 1993, letter f rom D. Morey (sw0C) to USNRC Docunent Control Desk, subject: Responses to Requests for Additional Information Regarding GL 92 01.

(1) The Mococ e , *'. Co , and onirra dde d USE values are ideMic AI Or lower Shell pides T> 6919 -1 ne d 3 6919 - 2. ; iherefore.,4he co r r e c t value for V4T USE cd E,0L / Er Py for plM e. 3G919 - 1 is G2 .

(7.) The c irc. , w eld unirr adiMed USE and V4 T OSE n+ EoL/ EFPY ar e- ebAn$ed io re flec3 ik e- a ppr oach o$ osia$ ike +10*F C.har py value. a <, w co n se rva b e_.

estimai c d Ak e. onir radi Me d USE i o d e m o n d e d e. Abd YT 4 USE 4 EOL/EFP'/

i5 $ realer ihan 50 if The lnwer shell Adal wcils onirradiaf ed OSE and VT 4 OSE at EoL/EFPY ct e c chan gc cl ao reflec3 an unirradla4c d OSE determined by 3Anlis4ical a n ,,1 y sis . ne vauwd analysis is described in Miachmed 2. .

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' Sur+eillance weld-4s-free-d4-f-f+ rent he:t th:n belt 1 %e > elds,

-add 4ti on a l-i nfo rma t4 on-requ ired-to-con f4 rm44 tense e ' : value-1 1

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Sumary File for Upper Shelf Energy Plant Name Baltiltw Meet No. Material 1/4T U$E 1/4T Unirred. Method of Ident. Type at Woutron USE Determin.

EOL/EFPT Fluence at Leirred.

EOL/EFPY USE Farley 2 Int. SheLL C6309 2 A $338 1 72 2.369E19 100 - Direct 87203-1 EOL: Int. Shell CT466 1 A 5334-1 62 2.369E19 100 Direct 3/31/2021 s7212-1 Lower C6888 2 A 5338 1 76 2.369E19 103 Direct Shell B7210-1 Lower C6293 1 A 5338 1 72 2.369E19 99 0iroct shell 8T'10 2 circ. Weld # + 10

• F bI SP5622 Linde -.nis.f*- 2.369E19 5;F *:

11 923 0091, sAW g (0 ~8'**~~

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Lower 83640 Linde # 7.67E18 # 5 ;'". ': + IO'F (0 Shell 0091, SAW -surv Antal 103(0 116(0 y,44 ,_ tu], Y Welds 20 923A/s Int. Shell NODA SMAW -4M + 7.67E18 -448 +- " - ' " .. +LO*F N Axial r..='

Clnar ry Welds 107 (0 13)(Q yo;4_. ygge 19-923A Int. Shell BOLA SMAW 131 7.67E18 148 sury.

Axial Weld Welds 19-9238 REFERENCES FOR FARLEY 2:

Fluence, heat ruber and LA;$[ values f rom Novenber 23, 1993, letter from D. Morey (SWOC) to USNRC Docunent Control Desk., subject: Responses to ReqJests for Additional Information Regarding GL 92-01.

(t) ~T b c cir c , w eld ( 11 - 9 2.3) , lower Skell adal Weldt ( 20 - 9 2 3 A /3) , ^n d id , sh c Il a x ial weld (19-923 A) unkradiat e j USE and PT 4 USE ai LOL/Er ry are ebe g c cl do r e dec + 4ke approach c4 vsA3 ike +to*F C%necy valoe as a eme r va%e edade of on,rrata;ca use so demonstede ibd VT 4 USE al EOL/ Erry 15 gred er 4kan 50-l

'"S u r v e i ' l ance-weld-4s-frw-a-4tMerent-heat-tha n-be4414ne-we146-

--add 444onal informat4onsequired-40-conf 4rm-14cencee's nlue t

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