ML17326A092
| ML17326A092 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 08/17/1999 |
| From: | POWERS R P AMERICAN ELECTRIC POWER CO., INC. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML17326A093 | List: |
| References | |
| C0799-05, NUDOCS 9908250194 | |
| Download: ML17326A092 (30) | |
Text
CATEGORY1REGULARYINFORMATION DISTRIBUTI i4SYSTEM(RIDS)r',ACCESSION NBR:9908250194 DOC.DATE:
99/08/17NOTARIZED:
YES(ACIL:50-315 DonaldC.CookNuclearPowerPlant,Unit1,IndianaMAUTH;MMEAUTHORAFFILIATION POWERS,R.P.
AmericanElectricPowerCo.,Inc.RECIE'.NA;K
'"RECIPIENT AFFILIATION RecordsManagement Branch(Document ControlDesk)DOCKET05000315
SUBJECT:
Application foramendtolicenseDPR-58,to changeTS3/4.4.5&.basesforTS3/4.4.5,3/4.4.6.2
&3/4.4.8toremovevoltage-based repaircriteria,F*
repaircriteriaSsleevingmethodologies fromUnit1TS&clarifybasessections.
DISTRIBUTION CODE:A001DCOPIESRECEIVED:LTR ENCLSIZE:TITLE:ORSubmittal:
GeneralDistribution NOTES:RECIPIENT
.IDCODE/NAME LPD3-1LACOPIESLTTRENCL1111RECIPIENT IDCODE/NAME STANG,JCOPIESLTTRENCL11G0INTERN~CENSENRR/DSSA/SRXB OGC/RP111,110NRR/DSSA/SPLB NUDOCS-ABSTRACT 111.1EXTERNAL:
NOAC11NRCPDRD'ENOTETOALL"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE~'TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083TOTALNUMBEROFCOPIESREQUIRED:
LTTR10ENCL9
~~I(I PmericenElectricP~er'ookNUotearPtanli@it1Steainenerator Re~iotaPrrject OneCookPrxeMl4910661646%72ANERICAN'I ECIICPOWERAugust17,1999C0799-0510CFR50.90DocketNo:50-315U.S.NuclearRegulatory Commission ATTN:DocumentControlDeskMailStop0-P1-17Washington, D.C.20555-0001 DonaldC.CookNuclearPlantUnit1TECHNICAL SPECIFICATION CHANGEREQUESTTECHNICAL SPECIFICATION 3/4.4.5rANDBASES3/4.4.5,3/4.4.6.2, AND3/4.4.8Pursuantto10CFR50.90,IndianaMichiganPowerCompany(I&M),theLicenseeforDonaldC.CookNuclearPlantUnit1,proposestoamendAppendixA,Technical Specifications (T/S),ofFacilityOperating LicenseDPR-58.I&M'proposes toamendUnit1T/S3/4.4.5andthebasesforT/S3/4.4.5,T/S3/4.4.6.2, andT/S3/4.4.8.Thisproposedamendment removesthevoltage-based repaircriteria, F*repaircriteria, andsleevingmethodologies fromtheUnit1T/Sandclarifies thebasessectionsaccordingly.
ThisproposedchangeispartoftheUnit1steamgenerator (SG)replacement effort.Theamendment istobeimplemented uponcompletion oftheSGreplacement.
I&Mwillbereplacing theoriginalUnit1Westinghouse model51SGswithBabcockandWilcox(B&W)SGshavingimprovedmaterials andenhanceddesignfeatures.
Thereplacement effortisscheduled tooccurduringthecurrentoutage,priortoUnit1restart.Thecurrentvoltage-based andF*repaircriteriaandsleevingmethodologies, intheUnit1T/S,incorporated viapastamendments tospecifically addressvariousSGtubedegradation mechanisms associated withtheWestinghouse Model51SGs,arenotapplicable tothereplacement SGs.Attachment 1providesthebackground andreasonfogthechange,adescription oftheproposedchange,thejustification forthechange,andouranalysisconcerning significant hazardsconsiderations'ttachment 2providesthecurrentT/Spages,marked-up toreflecttheproposedchanges.Attachment 3providestheproposed'evised T/Spages.Attachment 4providesanenvironmental assessment oftheproposedchange.r9908250i94 9908i7PDRADQCK050003l5t, PPDRAEP:America's EnergyPartner" II7WlZ+y~I' U.S.NuclearRegulatory Commission Page2C0799-05Inaccordance withtherequirements of10CFR50.91,copiesofthisletteranditsattachments havebeentransmitted totheMichiganPublicServiceCommission andtheMichiganDepartment ofPublicHealth.Shouldyouhaveanyquestions, pleasecontactMr.GordonP.Arent,ActingDirectorofRegulatory Affairs,at(616)465-5901, extension 1575.Sincerely, R.P.PowersVicePresident SRTOANDSUBSCRIBED BEFOREMEzzsItv1999NotarybicMyCommission ExpiresAttachments
)rZKRCQA.EGOlEGÃQSQ.5i2000/jmcc:A.C.Bakken,XII,w/attachments J.E.Dyer,w/attachments MDEQ-DWSRPDNRCResidentInspector, w/attachments REWhale I+y7HXQ.ClCtKKI~QC3~ZNNQggRoC$587)tCiOMQNO Attachment 1toC0799-05Page1BACKGROUND ANDREASONFORCHANGE;DESCRIPTION OFCHANGE;JUSTIFICATION FORCHANGE;AND10CFR50.92ANALYSISFORCHANGETOUNIT1TECHNICAL SPECIFICATIONS A.BACKGROUND ANDREASONFORCHANGEIndianaMichiganPowerCompany(I&M),theLicenseeforDonaldC.CookNuclearPlant,Units1and2;planstoreplacetheUnit1steamgenerators (SGs)duringthecurrentoutagepriortoUnit1restart.Thecurrentsurveillance requirements forsampleselection, inspection frequency, acceptance
- criteria, repairmethods,andrequiredreportswerespecifically developed forapplication tothedegradedWestinghouse model51SGs(OSGs)installed inUnit1.Theserequirements weredeveloped, inpart,topermittubestoremaininservicethatwereexperiencing varioustubedegradation mechanisms.
Afterreplacement oftheOSGs,thecurrentvoltage-based repaircriteria, F*repaircriteria, andsleevingmethodswillnolongerbeapplicable duetomaterialanddesignchangesincorporated intothereplacement steamgenerators (RSGs).Theanalysesperformed tosupportapplication ofthevoltage-based andF*repaircriteriawerespecifically basedontheOSGs.These.analyses willnolongerapplytotheRSGsfollowing replacement oftheOSGs.Inaddition, thecurrently approvedWestinghouse mechanical, Westinghouse laser-welded, andCombustion Engineering leaktightweldedsleevingprocesses willnolongerbeapplicable toUnit1.Thesesleevingprocesses weredeveloped specifically forWestinghouse SGmaterials anddesignandare,therefore, notapplicable totheBaWRSGs.B.DESCRIPTION OFCHANGEIntroduction ChangesareproposedtoamendTechnical Specification (T/S)3/4.4.5,"SteamGenerators,"
T/SBases3/4.4.5,"SteamGenerators TubeIntegrity,"
T/Sbases3/4.4.6.2, "Operational Leakage,"
andT/Sbases3/4.4.8,"Specific Activity,"
forUnit1tosupportSGreplacement.
Thereplacement effortisscheduled tooccurduringthecurrentoutage,priortoUnit1restart.TheRSGmaterials anddesignfeaturesfortubingandtubesupportsaredifferent fromtheOSGs.Inlightofthedesigndifferences, theanalysesperformed foruseofvoltage-based andF*repaircriteriaandsleevingmethodologies forUnit1tubesdonotapplytotheRSGs.Therefore, reference tothesecriteriaandmethodologies willnolongerbeappropriate intheT/S.
Iy7tg))Ct4I'$1 Attachment 1toC0799-05Page2DescritionandBasisforCurrentReuirements Thesurveillance requirements specified inT/S3/4.4.5forinspection ofSGtubesareintendedtoprovidereasonable assurance thatthestructural andleakageintegrity ofthetubesisacceptable forcontinued serviceandwillwithstand thepeakpressures thatcoulddevelopfollowing apostulated accident.
Themostsevereaccidentforpeakdifferential pressureonthetubesisthemainsteamline break(MSLB)accident.
Priortodevelopment ofspecialized repaircriteria(voltage-based andF*),thepluggingcriteriaforUnit1werebasedonatubeintegrity minimumwallthickness requirement established fortheplantaspartoftheoriginallicensing basis.Thespecialized criteriaforSGtubesandsleevesinthecurrentT/Sarebasedonanalysesperformed torequirements ofregulatory guide(RG)1.121andgenericletter(GL)95-05.Fortubesleftinserviceduetoapplication ofvoltage-based orF*repaircriteria, analyseshavebeenperformed todemonstrate acceptable probability oftubeburst,andtoprovideassurance thatMSLBleakageiswithinsite-specificlimits.Thecurrentrepairmethodsofsleevingprovideaprocesstore-establish theprimarysystempressureboundaryofatubecontaining degradation exceeding therepairlimit.Installation ofthesleeveprovidesaleaktightboundarythatspansthedefective areaandrestoresthestructural integrity ofthetubingtosatisfyRG1.121requirements.
Thecurrentprogramforin-service inspection ofSGtubesisbasedonamodification ofRG1.83,revision1,GL95-05,andF*criteria.
In-service inspection ofSGtubingisnecessary tomaintainsurveillance oftheconditions ofthetubesintheeventthatthereisevidence'fmechanical damageorprogressive degradation duetodesign,manufacturing errors,orin-service conditions thatcouldleadtocorrosion.
In-service inspection ofSGtubingalsoprovidesameansofcharacterizing thenatureandcauseoftubedegradation sothatcorrective measurescanbetaken.T/Sreporting requirements associated withapplication ofvoltage-basedrepairandF*repaircriteriaprovideassurance thattheNRCisawareofanyabnormalities detectedduringaninspection andprovidenotification astotheextentofapplication ofthecriteria.
T/S4.4.5providesthesurveillance requirements forsampleselection, inspection frequency, acceptance
- criteria, repairmethods,andrequiredreportstotheNRC.Provisions ofT/S4.4.5thatareaffectedbythisproposedT/Samendment aresummarized asfollows:
t~a41 Attachment 1toC0799-05Page3T/Ssurveillance requirement 4.4.5.2providestherequirement forSGtubesampleselection andinspection andprefacethelistofexceptions totherandomselection ofSGtubes.Thissectionalsostatesthattubesrepairedbysleevingdonotconstitute areasofpreviousdefectsorimperfections.
T/Ssurveillance requirement 4.4.5.2.b.l requiresalltubesnotpluggedorrepairedthatpreviously haddetectable wallpenetrations beincludedinthefirstsample.T/Ssurveillance requirement 4.4.5.2.b.4 requiresthat,forallindications leftinserviceasaresultofapplication ofthe-tubesupportplate(TSP)voltage-based repaircriteria, the,indications shallbeinspected bybobbincoilprobeduringfuturerefueling outages.T/Ssurveillance requirement 4.4.5.2.c requiresthattubesthatremaininserviceduetotheapplication oftheF*repaircriteriawillbeinspected intherollexpandedregionduringfutureoutages.T/Ssurveillance requirement 4.4.5.2.e requiresthedetermination ofTSPintersections havingoutsidediameter, stresscorrosion cracking(ODSCC)indications bebasedonarandomsampleinspection ofatleast20%ofthetotalnumberoftubesinspected overtheirfulllength.Implementation oftheSGtube/TSPpluggingcriteriarequiresa100%bobbincoilinspection forhotlegsupportplateintersections andcoldlegintersections downtothelowestcoldlegTSPwithknownODSCCindications.
T/Ssurveillance requirement 4.4.5.2.f requiresthatinspection ofsleevesfollowthecriteriaforfirstsampleselection andsampleexpansion according totable4.4-2.T/Ssurveillance requirement 4.4.5.2alsospecifies thecriteriatoclassifythesampleinspection resultsintothreecategories.
The"note"tothesecriteriastatesthatpreviously degradedtubesorsleevesmustexhibitsignificant
(>10%)furtherwallpenetrations tobeincludedinthepercentage calculation definedintheclassification criteria.
T/Ssurveillance requirement 4.4.5.3.a requiresthefirstin-service inspection tobeperformed withinaspecified intervaloftimefollowing initialcriticality.
Frequencies ofsubsequent in-service inspections arealsoaddressed.
Attachment 1toC0799-05Page4T/Ssurveillance requirement 4.4.5.4.a.1 defines"imperfections" forbothtubesandsleevesasexceptions todimensions, finishorcontourfromthatrequiredbyfabrication drawingsorspecifications.
T/Ssurveillance requirement 4.4.5.4.a.2 defines"degradation" forbothtubesandsleevesasservice-induced
- cracking, wastage,wear,orgeneralcorrosion oneithertheinsideoroutsideofthetubeorsleeve.T/Ssurveillance requirement 4.4.5.4.a.3 defines"degraded tubeorsleeve"ashavinganimperfection ofgreaterthanorequalto20%ofthenominalwallthickness.
T/Ssurveillance requirement 4.4.5.4.a.5 defines"defect"asanimperfection thatexceedsthedefinedrepairlimit.T/Ssurveillance requirement 4.4.5.4.a.6 definesthe"repair/plugging limit"fortubingorsleevedtubesastheimperfection depthequalto40%ofthenominaltubewallthickness.
Theplugginglimitimperfection depthforlaserweldedsleevesisequalto23%ofthenominalsleevewallthickness.
Theplugginglimitimperfection depthfornon-laserweldedsleevesisequalto29%ofthenominalsleevewallthickness.
Thisdefinition doesnotapplytodefectsinthetubesheet thatmeetthecriteriaforanF*tube.T/Ssurveillance requirement 4.4.5.4.a.7 defines"unserviceable" asthecondition fortubesandsleevesthatleakorwouldnotmaintaintheirstructural integrity undertheconditions specified in4.4.5.3.c.
T/Ssurveillance requirement 4.4.5.4.a.8 defines"inspection" asthemeansofdetermining thecondition oftheSGtubeorsleevefromthepointofentry(hotlegside)completely aroundtheU-bendtothetopsupportofthecoldleg.ForatubeinwhichtheTSPelevation interimplugginglimithasbeenapplied,the"inspection" willincludeallthehotlegintersections andcoldlegintersections downto,atleast,thelevelofthelastcrackindication.
T/Ssurveillance requirement 4.4.5.4.a.9 definesandpermits"sleeving" oftwotypes.Tubesupportplatesleevesarecenteredaboutthetubesupportplateintersection.
Tubesheet sleevesstartattheprimaryfluidtubesheet interface andextendthroughtheentiretubesheet.
T/Ssurveillance requirement 4.4.5.4.a.10 definesthe"tubesupportplaterepairlimit"usedtodisposition alloy600SGtubesforcontinued servicethatareexperiencing predominately axially-oriented ODSCCconfinedwithinthe Attachment 1toC0799-05Page5thickness ofthetubesupportplates.Attubesupportplateintersections, theplugginglimitisbasedonmaintaining SGtubeserviceability asdetermined byvariousbobbinvoltagecriteria.
Mid-cycle repairlimitsarealsodefined.T/Ssurveillance requirement 4.4.5.4.a.ll definestheF*"distance" asthedistancefromthe'ottom ofthehardrolltransition towardthebottomofthetubesheet thathasbeenconservatively determined tobe1.11inches(notincluding eddycurrentuncertainty).
T/Ssurveillance requirement 4.4.5.4.a.12 definesthe"F*tube"asaSGtubewithdegradation, belowtheF*distance, equaltoorgreaterthan40%,butthathasnoindications ofdegradation (i.e.,noindication ofcracking) withintheF*distance.
T/Ssurveillance requirement 4.4.5.4.a.13 defines"tuberepair"assleevingdescribed byreportslistedinT/Ssurveillance requirement 4.4.5.4.c.
Discussion allowsuseofsleevingaspreventive measuresandforamethodofreturning previously pluggedtubestoservicefollowing appropriate inspections.
T/Ssurveillance requirement 4.4.5.4.b statesthataSGshallbedetermined operableaftercompleting thecorresponding actionsrequiredbytable4.4-2.T/Ssurveillance requirement 4.4.5.4.c identifies thetopicalreportsforsleevingmethodologies approvedforuseonUnitl.T/Ssurveillance requirement 4.4.5.5.a requiresthatthenumberoftubespluggedorsleevedbereportedtotheNRCwithin15daysofthecompletion ofeachin-service inspection oftheSGtubes.T/Ssurveillance requirement 4.4.5.5.b requiresthatthenumberoftubesandsleevesinspected bereportedandtubesthatarepluggedorsleevedbeidentified intheannualoperating report.T/Ssurveillance requirement 4.4.5.5.d requiresnotification totheNRCofimplementation ofvoltage-based repairpriortoreturning theSGstoserviceifanyofthefollowing conditions arise.Theestimated end-of-cycle(EOC)leakagelimitexceedsthatassumedinthelicensing basisoffsitedosecalculation fortheMSLB.
)lg.5'l>>,~l Attachment 1toC0799-05Page6Circumferentialdetectedatintersections.
crack-like thetubeindications aresupportplateIndications areidentified thatextendbeyondtheconfinesofthetubesupportplate.Indications areidentified atthetubesupportplateelevations thatareattributable toprimarywaterstresscorrosion cracking.
Thecalculated conditional burstprobability basedonprojected EOCvoltagedistribution exceeds1x10'.Thisdetermination alsorequiresanassessment ofthesafetysignificance oftheoccurrence.
T/Stable4.4-2providestherequiredsamplesize,resulting
- category, andrequiredactionsforfirst,second,andthirdsampleSGtubeinspections.
T/Sbases3/4.4.5addresses requirements ofT/Ssurveillance 4.4.5.Additionally, T/Sbases3/4.5.6.2 addresses theanticipated primary-to-secondary leakageassociated withtheMSLB,whichisbasedontheSGtubestructural integrity condition requiredbyT/Ssurveillance 4.4.5.T/Sbases3/4.4.8addresses thelimitations ontheprimarycoolantactivitybasedonmaintaining acceptable offsitedosesfollowing asteamgenerator tuberupture(SGTR)event.Thisbasessectionwaspreviously modifiedtoincludeaMSLBcaseforhighprimary-to-secondary leakage(120gpm)ataprimarycoolantactivitylevelcorresponding to1%failedfuel.DescritionofProosedModifications toUnit1Technical Secifications I&MproposestoreviseT/S3/4.4.5,T/Sbases3/4.4.5,T/Sbases3/4.4.6.2, andT/Sbases3/4.4.8.Theserevisions removethemodifications thatweremadetotheUnit1T/StoaddressthevariousSGtubedegradation mechanisms thathaveoccurredontheUnit1OSGs.Incorporation oftheseproposedchangeswillcausetheUnit1T/Stoessentially revertbacktotheoriginallicensing bases(exceptforoperational leakagelimits)thatareconsistent withboththeStandardTechnical Secifications forWestinhousePWRPlants(NUREG-0452) andtheUnit2requirements.
TheproposedT/Schangesareasfollows.T/Ssurveillance requirement 4.4.5.2,SGtubesampleselection andinspection.
)Ilg Attachment 1toC079p-05Page7T/Ssurveillance requirement 4.4.5.2isrevisedtoremovereference topreviousdefectsorimperfections repairedbysleeving.
T/Ssurveillance requirement 4.4.5.2.b.1 isrevisedtoremovethereference tosleeving.
T/Ssurveillance requirements 4.4.5.2.b.4, 4.4.5.2.c, 4.4.5.2.e, and4.4.5.2.f aredeleted.T/Ssurveillance requirement 4.4.5.2.d isrenumbered.
T/Ssurveillance requirement 4.4.5.2isrevisedtoremovethereference tosleeving.
T/Ssurveillance requirement 4.4.5.3,inspection frequencies.
T/Ssurveillance requirement 4.4.5.3.a isrevisedtoapplytothesameinitialintervalforin-service inspection toRSGsaswasdonefortheoriginalOSGs.T/Ssurveillance requirement 4.4.5.4,acceptance criteria.
T/Ssurveillance requirement 4.4.5.4.a items1,2,3,6,7,and8arerevisedtoremovereferences tosleeving.
T/Ssurveillance requirement 4.4.5.4.a items5and6arerevisedtoremovereferences torepairlimits.T/Ssurveillance requirement 4.4.5.4.a.5 isrevisedtodefineadefectintermsoftheplugginglimit.T/Ssurveillance requirement 4.4.5.4.a.6 isrevisedtoremovethediscussion ofapplicability toF+tubesandsleeves.T/Ssurveillance requirement 4.4.5.4.a.8 isrevisedtoremovethereference tointerimplugginglimit.T/Ssurveillance requirement 4.4.5.4.a items9,10,11,12,and13aredeleted.T/Ssurveillance requirement 4.4.5.4.b isrevisedtoremovereferences tosleevesandrepairlimits.T/Ssurveillance requirement 4.4.5.4.c isdeleted.T/Ssurveillance requirement 4.4.5.5,Reports.T/Ssurveillance requirements 4.4.5.5.a, 4.4.5.5.b.1, and4.4.5.5.b.3 arerevisedtoremovereferences tosleeving.
I)~~ghL1ItIII, Attachment 1toC0799-05Page8T/Ssurveillance requirement 4.4.5.5.d isdeleted.T/STable4.4-2.Table4."4-2isrevisedtoremovereferences tosleeving.
BasesT/S3/4.4.5,SteamGenerator TubeIntegrity.
T/Sbases3/4.4.5arerevisedtoremoveanyreferences torepairofdefective tubes,repairlimits,andsleeving.
Detailsonthevoltage-based repairlimitsareremovedandallreferences toapprovedmethodologies forsleevingareremoved.BasesT/S3/4.4.6.2, Operational Leakage.T/Sbases3/4.4.6.2 arerevisedtoremovethedetailofcrackgrowthandexpectedmaximumprimary-to-secondary leakageduringaMSLB.BasesT/S3/4.4.8,SpecificActivity.
T/Sbases3/4.4.8arerevisedtoremovetheparagraph thatdiscusses MSLBoffsitePosesataprimary-to-secondary leakrateof120gpm.C.JUSTIFICATION FORCHANGEForUnit1operation aftersteamgenerator replacement, thevoltage-based andF*requirements willnolongerbeapplicable.
TheT/Sacceptance limitswillbebasedonthrough-wall criteriathatrequiretubesbepluggedwhenimperfections exceedtheplugginglimitof40%ofthenominaltubewallthickness.
Theproposedprogramforperiodicin-service inspection ofthereplacement SGsmonitorstheintegrity oftheSGtubingtoprovidereasonable assurance thatthereissufficient timetotakeproperandtimelycorrective actionifanytubedegradation ispresent.Theproposedprogramisconsistent withNUREG-0452 andwasthebasisfortheoriginalT/SissuedwiththeUnit1operating license,DPR-58.ThepurposeoftheT/Splugginglimit,inconjunction withsurveillance andmaintenance
- programs, istoprovidereasonable assurance thattheSGtubesacceptedforcontinued servicewillretainadequatestructural andleakageintegrity duringnormal,transient, andpostulated accidentconditions.
AlthoughD.C.CookisnotaGDCplant,I&Mhasdetermined thattheRSGdesignisconsistent withgeneraldesigncriteria(GDC)14,15,30,31,and32of10CFR50,appendixA.Compatibility withtheseGDCs,as lsaA)I Attachment 1toC0799-05Page9discussed below,supportstheapplication ofT/Sacceptance limitsbasedonthrough-wall criteria.
RSGdesign,surveillance, andmaintenance meettherequirements ofGDC14.TheRSGportionsofthereactorcoolantpressureboundaryaredesigned, fabricated, erected,andtestedtohaveanextremely lowprobability ofabnormalleakage,rapidlypropagating failure,orgrossrupture.TheRSGdesignmeetstheapplicable ASMECoderequirements andcomplieswith10CFR50.55a.RSGdesign,surveillance, andmaintenance meettherequirements ofGDC15.TheRSGportionsofthereactorcoolantsystemaredesignedwithsufficient margintoprovidereasonable assurance thattheapplicable stresslimitsarenotexceededduringanycondition ofnormaloperation oranticipated operational occurrences.
TheRSGtubinghasbeenstructurally evaluated undertheapplicable requirements ofASMESectionIII,1989Edition,forServiceLevelsA,B,C,"andD(normal,upset,emergency, andfaultedconditions, respectively).
RSGdesignmeetstherequirements ofGDC30.TheRSGportionsofthereactorcoolantpressureboundaryaredesigned, fabricated, erected,andtestedtothehighestpractical qualitystandards bymeetingtheASMECodeand10CFR50,appendixB.Detection andidentification ofthelocationofRSGleakageisthroughexistingplantinstrumentation andprocedures.
RSGdesignmeetstherequirements ofGDC31.TheRSGportionsofthereactorcoolantpressureboundaryaredesignedwithsufficient margintoassurethat,whenstressedunderoperating, maintenance, testing,andpostulated accident.
conditions:(1) theboundarybehavesinanon-brittle manner;and(2)theprobability ofrapidlypropagating fractureisminimized.
Thedesignconsiders servicetemperatures andotheroperating maintenance, testing,andpostulated accidentconditions; uncertainties indetermining materialproperties; effectsofradiation onmaterialproperties;
- residual, steadystate,andtransient stresses; andsizeofindications.
RSGdesign,surveillance, andmaintenance meettherequirements ofGDC32.RSGportionsofthereactorcoolantpressureboundaryaredesignedtopermitperiodicinspection andtestingofimportant areasandfeaturestoassessstructural andleak-tight integrity.
TheRSGhastubingfabricated fromthermally treatedSB-163material(Alloy690)whichisexaminedbyeddycurrentmethodstotherequirements ofASMESectionIII,NB-2550.Inaccordance withNUREG-0452 andconsistent withtheoriginallicensing basisforUnit1,thedesignrequiresthatthedepthofanallowable outsidediameterflawshallnotexceed40%ofthenominaltubewallthickness.
Ilh,Itlf~n Attachment 1toC0799-05Page10Uponreplacement oftheSGs,thecurrentsleevingmethodology willnolongerbeapplicable.
Theproposedchangeisrequiredbecausethesleevingmethodologies referenced intheUnit1T/SarespecifictoWestinghouse model51SGsandhavenotbeenanalyzedorapprovedbytheNRCforusewiththeRSGsmanufactured byBSW.ThischangeremovestheinterimSGtubepluggingcriteriafromtheT/Sandreinstates theoriginalT/Scriteriaconsistent withUnit2(whichdoesnothavesignificantly degradedsteamgenerators).
Thesecriteriaareinaccordance withNUREG-0452.
Thecriterion fortubepluggingisbasedonaminimumwallthickness duetowastageasdetermined byASMESectionXI.BecausetheproposedT/Ssurveillance requirements donotallowforcontinued operation withvoltagebasedandF*indications, theprobability ofaSGTRisnotincreased.
Therefore, implementation ofthisproposedT/Samendment requestwillprovidereasonable assurance thattheUnit1SGsmaintainadequatestructural andleakageintegrity consistent withGDC14,15,30,31,and32*of10CFR50,appendixA.Unit1willcontinuetoapplytheT/Smaximumprimary-to-secondary leakagelimitof'150gallonsperday(gpd)throughanyoneSGtominimizethepotential forexcessive leakageduringplantconditions.
TheEPRIrecommended 150gpdlimitprovidesforleakagedetection andplantshutdownintheeventofanunexpected tubeleakandminimizes thepotential forexcessive leakageortubeburstintheeventofMSLBorlossofcoolingaccident(LOCA)conditions.
Thedesignbasisdosescalculated forpostulated accidents involving degradation ofSGtubes,suchasSGTRandMSLBaccidents, aspresented inUFSARchapter14accidentanalysishavebeenevaluated.
TheSGTRconsequences continuetobeboundedbythedesignbasisduetotheallowable leakageratespecified bythischange.TheproposedT/Sleakagerateismaintained at150gpdperSG.However,amaximumleakageof500gpdperSGandtotalleakageof1440gpdforallfourgenerators wasusedfordetermination ofoffsitedoseinUFSARchapter14.TheMSLBconsequences aredecreased byinstallation oftheRSGsduetothereduction inprimary-to-secondary leakageduringtheMSLB.Undertheapprovedinterimpluggingcriteria, aleakrateof8.4gpmwasdetermined tobetheupperlimitforprimary-to-secondary leakageinthefaultedsteamgenerator.
Thisleakage,combinedwiththe150gpdleakagefromthenon-faulted SGs,wasdetermined tolimittheoffsitedoseto10%ofthe10CFR100limits.Following replacement oftheSGs,theleakageislimitedduringtheMSLBto150gpdforboththefaultedandunfaulted SGs.Therefore, theUnit1MSLBdosewillbeboundedbythecurrentUnit2doseanalysis, whichislessthan10%of10CFR100limits.
Attachment 1toC0799-05PagellAmendment 166toDPR-58addedadiscussion inthebasessectionsofT/S3/4.4.5andT/S3/4.4.8regarding theMSLBoffsitedose,whichwascalculated usingassumedSGleakageof120gpm.Subsequently, amendment 178toDPR-58imposedamorelimitingcondition basedona12.6gpmSGleakagefortheMSLBtolimitoffsitedosesto10%.ofthe10CFR100limits(thisvaluewaslaterrevisedto8.4gpm).Amendment 178revisedT/Sbases3/4.4.5toremovethereference tothe120gpmMSLBoffsitedoseevaluation, butinadvertently didnotreviseT/Sbases3/4.4.8.Becausethediscussion regaxding the120gpmSGleakratenolongerapplies,itwillberemovedfromT/Sbases3/4.4.8bythischange.D.BASESFORNOSIGNIFICANT HAZARDSDETERMINATION (10CFR50.92ANALYSIS)
IndianaMichiganPowerCompany,theLicenseeforDonaldC.CookNuclearPlantUnit1,proposestoamendTechnical Specification (T/S)3/4.4.5,"SteamGenerators,"
T/SBases3/4.4.5,"SteamGenerators TubeIntegrity,"
T/SBases3/4.4.6.2, "Operational Leakage,"
andT/SBases3/4.4.8,"Specific Activity,"
tosupportsteamgenerator (SG)replacement.
I&Mwillbereplacing theoriginalUni.t1Westinghouse model51SGswithB&WSGs.Thereplacement effortisscheduled tooccurduringthecurrentoutage,priortoUnit1restart.I&Mhasevaluated thisproposedT/Samendment anddetermined thatitdoesnotinvolveasignificant hazard.According to10CFR50.92(c),
aproposedamendment toanoperating licensedoesnotinvolveasignificant hazardifoperation ofthefacilityinaccordance withtheproposedamendment doesnot:involveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated; orcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated; or3.involveasignificant reduction inamarginofsafety.NoSinificantHazardsAnalsisCriterion 1:Theproposedchangedoesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.
Thischangeremovestheinterimsteamgenerator tubepluggingcriteriafromtheT/Sandreinstates theoriginalT/Scriteriaconsistent withUnit2(whichdoesnothavesignificantly degraded IIIeq~dt,C Attachment 1toC0799-05Page12steamgenerators).
ThecurrentT/Sallowforcontinued operation withtubesthatdemonstxate indications perF*andvoltage-based criteria.
ThebasisusedtojustifytheinterimcriteriaisspecifictotheUnit1originalsteamgenerators (OSGs)anddoesnotapplytothereplacement steamgenerators (RSGs).Theproposedchangereturnsthepluggingcriteriaforthesteamgenerator tubestotheoriginallicensing basis.Thecriteriaareinaccordance withNUREG-0452, (old)"Standard Technical Specifications."
Thepluggingcriteriaarebasedonaminimumwallthickness duetowastageasdetermined byASMESectionXI.Theproposedchangeisconservative innaturebecauseitdoesnotallowforcontinued operation withF*andvoltage-based degradedtubes.Becauseofthis,theprobability ofasteamgenerator tuberupture(SGTR)isnotincreased.
Thepotential foraSGTRisalsonotincreased asdemonstrated inthequalification analysisandtestingfortheRSGs.Theprogramforperiodicin-service inspection monitorstheintegrity oftheSGtubingtoprovidereasonable assurance thatthereissufficient timetotakeproperandtimelycorrective actionifanytubedegradation isdetected.
Thetubeinspections themselves arenotinitiators ofaSGTR.Therefore, thischangeisnotexpectedtoincreasetheprobability ofaSGTRduringnormaloraccidentconditions.
Unit1willcontinuetoapplytheT/Smaximumprimary-to-secondary leakagelimitof150gallonsperday(gpd)throughanyoneSGtominimizethepotential forexcessive leakage.TheEPRI-recommended 150gpdlimitprovidesforleakagedetection andplantshutdownintheeventofanunexpected tubeleakandminimizes thepotential forexcessive leakageortubeburstintheeventofmainsteamline break(MSLB)orloss-of-coolant accident(LOCA)conditions.
Thislowerlimitismorerestrictive thanthelimit(500gpdperSGandtotalleakageof1440gpd)utilizedfordetermination ofoffsitedoseandalsoprovidesfurtherassurance thattheprobability ofaSGTRisnotincreased.
Thedesignbasisdosescalculated forpostulated accidents involving degradation ofSGtubes,suchasSGTRandMSLBaccidents, aspresented inUFSARchapter14accidentanalysis, havebeenevaluated.
TheSGTRconsequences continuetobeboundedbythedesignbasisanalysesduetotheallowable leakageratespecified bythischange.TheproposedT/Sleakagerateismaintained at150gpdperSG.However,themaximumleakageof500gpdperSGandtotalleakageof1440gpdforallfourgenerators wasusedtodetermine offsitedoseinUFSARchapter14.TheMSLBconsequences aredecreased byinstallation oftheRSGsduetothereduction inprimary-to-secondary leakageduring'theMSLB.Undertheapprovedinterimpluggingcriteria, aleakrateof8.4gpmwasdetermined tobetheupperlimitforallowable primary-to-Ilga' Attachment 1toC0799-05Page13secondary leakageinthefaultedsteamgenerator.
Thisleakage,combinedwiththe150gpdleakagefromthenon-faulted SGs,wasdetermined tolimittheoffsitedoseto10%ofthe10CFR100limits.Following replacement oftheSGs,theleakageislimitedduringtheMSLBto150gpdforboththefaultedandunfaulted SGs.Therefore, theUnit1MSLBdosewillbeboundedbythecurrentUnit2doseanalysis, whichislessthan10%of10CFR100limits.Therefore, theproposedchangedoesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.
Criterion 2:Theproposedchangedoesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.
Removingapplication ofvoltage-based repaircriteria, F*repaircriteria, andsleevingmethodologies uponinstallation oftheRSGswillnotintroduce significant oradversechangestotheplantdesignbasisthatcouldleadtoanewordifferent kindofaccidentbeingcreated.Thischangedoesnotchangetheoverallobjective ofsurveillance activities
-maintaining thestructural integrity ofthisportionofthereactorcoolantsystem.Thesurveillance activities areperformed duringoutages.Theproposedchangeinthesurveillance programreturnstheprogramtotheinitiallicensing basis.Nonewfailuresarecreated.Therefore, theproposedchangedoesnotcreatethepossibility ofanewordifferent kindofaccidentpreviously evaluated.
Criterion 3:Theproposedchangedoesnotinvolveasignificant reduction inamarginofsafety.Removingtheapplication ofvoltage-based andF*repaircriteriaandsleevingmethodologies doesnotinvolveareduction inamarginofsafety.TheRSGtubinghasbeenshowntoretainadequatestructural andleakageintegrity duringnormal,transient, andpostulated accidentconditions consistent withGDC14,15,30,31,and32of10CFR50appendixA.TheRSGtubinghasbeendesignedandevaluated consistent withtheASMESectionIII,1989edition.TheproposedpluggingcriteriaarebasedonASMESection'I anddonotallowforoperation withindications identified byF*andvoltage-based criteria.
Theproposedprogramforperiodicin-service inspection oftheRSGsmonitorstheintegrity oftheSGtubingtoprovidereasonable assurance thatthereissufficient timetotakeproperandtimelycorrective actionifanytubedegradation ispresent.Theproposedprogram
~l'lt' Attachment 1toC0799-05Page14isconsistent withNUREG-0452 andwasthebasisfortheoriginalUnit1T/Ssurveillance program.Theproposedchangemaintains theT/Smaximumprimary-to-secondary leakageat150gpdpergenerator tominimizethepotential forexcessive leakage.Thislimitprovidesforleakagedetection andshutdownintheeventofanunexpected tubeleakandminimizes thepotential forexcessive leakageortubeburstintheeventofaMSLBorLOCA.Becausethislimitismaintained, themarginofsafetyismaintained.
Therefore, itisconcluded thatthischangedoesnotinvolveasignificant reduction inamarginofsafety.