ML17059B243
| ML17059B243 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 08/09/1996 |
| From: | FORTIN A, GLEASON T E GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML17059B240 | List: |
| References | |
| 25A5585, 25A5585-R04, 25A5585-R4, NUDOCS 9608210140 | |
| Download: ML17059B243 (44) | |
Text
ATTACHMENT8.4STABILIZERINSTALLATIONSPECIFICATIONNO.25A5585REV.496082iOi40960814,!,PDRADOCK05000220,.'.PDR,",
EISIDENT:DOCUMENTTITLEREVISIONSTATUSSIKETSTABILIZERINSTALLATION25A5585SHNO.1REV.4TYPE:INSTALLATIONSPECFMF:NINEMILEPOINT1MPLNO:PRODUCTSUMh96KSEC.7'HISITEMISORCONTAINSASAFETY-RELATEDITEMYESgNOQEQUIPCLASSCODEREVISIONRM41609II/18/94PRELIMINARYISSUE12/28/94V.PENCEGeneralDocumentChangeRM41871RARACHKBY:T.APOLLONIO'NGR:V.PENCE01/26/95V.PENCEENC¹CN02141RACKDBY:A.FORTINENGR:V.PENCEP.E.PANSOYune7,19953CHANGEDPERCN02583CHKBY:P.E.PANSOYENGR:TGLEASONT.E.GLEASONgga09SRAECNNO.CN04208CHK.BY:A.FORTINENGR:T.GLEASONPRINTSTOMADEBYV.W.PENCE11/18/94APPROVALST.E.GLEASON11/18/94GENERALELECTRICCOMPANY175CURTNERAVENUESANOSECALIFORNIA95125CHEDBY:T.E.GLEASON11/18/94MSWORD(08/08/963:37PM)ISSUEDR..AHMANN11/18/94CONTONSHEET2
Qy25A5585SHNO.2REV.41.SCOPE1.1Purugse.ThisspecificationprovidestheengineeringrequirementsforinstallingstabilizersandH8weldbracketswhichreplacetheHlthroughH8horizontalshroudweldsatNineMilePointl.1.2Ifanyconflictexistsbetweenthisdocumentandanyotherdocumentreferencedherein,thisdocumentshallgovern.1.3Thisdocument,alongwiththereactormodificationandinstallationdrawing,definesalltheengineeringrequirementsforinstallationoftheshroudstabilizers.1.4Asusedherein,theterm"Installer"referstothecompanyorpersonnelcontractedbythePlantOwnertoinstalltheshroudstabilizers.2.APPLICABLEDOCUMENTS2.1eneralEletricDumen.Thefollowingdocumentsformapartofthisspecificationtotheextentspecifiedherein.2.1.1SuonDcumentsC.25A5585,ShroudRepairHardwareDesignSpec.25A5586,ShroudRepairCodeDesignSpec.107E5679,ReactorModificationd.21A2040,CleaningandCleanlinessControle.D50YP5,Nickel-GraphiteThreadLubricantf.112D6570,LowerWedgeg.112D6546,TieRodSpringAssemblyh.112D6565,UpperWedge112D6575,UpperSupportAssemblyj.112D6577,UpperContactk.112D6576,LowerSupportAssembly112D6574,UpperSpringAssemblym.112D6566,MidSupportn.112D6575,MidSupportAssemblyo.112D6588,TopSupport
025A5585SHNO.3REV.4p.178B3732,PlateBracketAssembly178B3735,UpperToggleBoltr.112D6618,Clamp/Spacer262B1285,Spacer148C6912,BottomSpringSpacer2.1.2SulementalDocumentsa.NEDC-31735PGEBWROperator'sManual-MaterialsandProcesses2.2odesandStandards.Thefollowingcodesandstandardsofthelatestissue(orspecifiedissue)formapartofthisspecificationtotheextentspecifiedherein.2.2.1ericanSoifehanicalEnneersASBilerandPrsureVessldeSectionXI,RulesforInserviceInspection,1983EditionwithAddendathroughSummer1983..3.DESCRIPTION3.1ThepurposeofthestabilizerinstallationistostructurallyreplacehorizontalgirthweldsHlthroughH7intheshroudandshroudsupportcylinder.Welddesignationsandthedesignrequirementsforthestabilizersaredefinedinthe2.l.l.adesignspecification.Theinstallationoftheshroudstabilizersinvolveselectricdischargemachining(EDM)ofsomeslotsandholesintheexistingstructure,assemblingthestabilizerhardwareinthereactor,andpreloadingthethreadedfasteners.Nostructuralweldingordefectremovalbymachiningisinvolved.4.RESPONSIBILITIES4.1TheInstallershallacceptfullresponsibilityforhiswork.TheInstallershallcomplywiththerequirementsofthisdocumentandthesupportingdocumentslistedherein.4.2TheInstallershalltaketheresponsibilityforcoordinationofhisworkwiththeworkofothersincludingthecoordinationofworkplanningandradiationmonitoringwiththePlantOwner.4.3TheInstallershallberesponsibleforprovidingallspecializedhandling,alignment,andinstallationequipment,asmaybenecessarytoperformthiswork,exceptasotherwiseagreedtobythePlantOwner.4.4TheInstaller,exceptasotherwiseagreedtobythePlantOwner,shallberesponsibleformachiningasspecifiedandlimitedbytheapplicablemodificationdrawing.
'C OeGENuclear25A5585SHNO.4REV.44.5TheInstallershallsupplyadequatelyqualifiedpersonnelforsupervisionandforperformingthetasksrequiredtocompletethestabilizerinstallation.5REQUIREMENTS5.1General5.1.1Duringinstallation,theInstaller,exceptasotherwiseagreedtobythePlantOwner,shallcompletedatasheetsandqualitycontrolchecksheetsasrequiredbythespecificationsandinstructionslistedinthisdocument.TheInstallershallkeeprecords,etc.,forfuturereference.Videotapesshallbetakenofthecompletedrepair.Tabulardataentriesdesignatedforas-builtmeasurementsonthe.installationdrawingshallberecorded.5.1.2ProceduresandinstallationequipmentshallbedevelopedanddesignedtominimizethepotenualofloosepartswithintheRPV.5.1.9Followingcompletionoftheinstallationofthestabilizers,verification,inspectionandsignoffshallbeperformedtoensurethatallobjectshavebeenremovedfromtheRPV.5.1.4Alluncontaminatedtoolsshallbestoredinanuncontaminatedcontrolledareaandbroughtto~~theworkareaonlyasneededforfit-upandinstallation.5.1.5Referto2.1.2.aformiscellaneousconsumablesapprovedforuseinthereactorvessel.5.1.6AllThreadconnectionsthataretorquedduringtheinstallationprocessshallbecoatedwithD50YP5B,ThreadLubricant.2.2~P.2.1~PCh5.2.1.1AllworkshallbedonewiththeconcurrenceofandpertheinstructionsoftheauthorizedsiteHealthPhysicsPersonnel.Atnotimeshalltheirrequirementsfordosimetermonitors,protectiveclothingordevices,timelimits,exposurelimits,etc.,beviolated.5.2.1.2Machiningoncontaminatedsurfaces,asrequired,shallbedoneinaccordancewithHealthPhysicsandSafetyPersonnelrequirements.5.2.1.3Radiationcontrolpracticesshallbeusedtoreduceexposuretoworkerstolevelswhichareaslowasreasonablyachievable(ALARA).2.2.2~PHP5.2.2.1Concernforpersonnelsafetyshallgovernallworkoperations.Allpersonnelworkinginhazardouslocationsshallbeunderconstantsurveillancebyotherpersonnel.Allelectricequipmentshallbegroundedordoubleinsulated.Weldingcablesandleadsshallb'eingoodcondition.
(
OO25A5585SHNO.5REV.45.2.2.2Allworkareasshallbekeptneatandorderly.Protectivemeasuresanddevicesshallbeusedtokeepalltools,equipment,andmaterialsfrominadvertentlydroppingintotheRPV.5.2.2.3Careshallbeexercisedtokeepcontaminationofarticleswhichmustenterandleavecontaminationzonestoaminimum.Inallcases,siteradiationcontrolrequirementsshallbemet.SHBLUGscRiBE.UNEO00V)5.3leaninandleanlinessntrol5.3.1Duringthisstabilizerinstallationprogram,cleaningandcleanlinesscontrolshallbeinaccordancewiththedocumentlistedinparagraph2.l.l.d,andNMPCSiteProcedures.Inaddition,nographiteleadpencilsareallowedtocontactstainlesssteelandnickelalloys,andanyexpendableitemsincludingmarkersshallmeettherequirementsofparagraph2.1.2.aandNMPCsiteprocedures.SDATUM2.25I(1.29)I'.4~ii5.4.1DELETED.4.-~S"'.S~if*i*lE*ldll***d,fvicinityofthecoreplatewedges.TopHatFuelSupportCoversshallbeinstalledtoassurethatnothingcanbe.droppedintotheControlRodGuideTubes.5.4.3ReactorTemerature.Thereactorwatertemperatureshallbelessthan100F,howevertheShutdownCoolingflowmustbeoffwhenevertheinstallationactivityinprogressinvolvescriticalremoteunderwaterhandlingintheannulusarea.6.INSTALLATIONREQUIREMENTS6.1Theinstallationsequencedescribedbelowisnotitselfmandatory,solongasallspecifiedinstallationrequirementsareaccomplished.Toassistinevaluatingalternativesequences,theintentofsomerequirements,whicharenotselfevident,aresummarizedinthestepdescription.CAUTION:Severalpiecepartsaretobemachinedbasedonin-reactormeasurementsataspecificreactorazimuth.Thesepartsshallthenbedesignatedbyspecificserialnumber,asrecordedontheas-builtdatatableondrawing107E5679,forthatspecificazimuth.6.2Shroudheadbolt(SHB)lugs,ontheshroud,arespecifiedonthe107E5679ModificationDrawingasdatumsforthestabilizerinstallation,andformachiningslotsintheshroudheadflange.TheseSHBlugsshallbeidentifiedatazimuths90',170'70'nd350',includinganindependentverificationasaprerequisitetoanyphysicalwork.Priortoremoval0theshroudheadlaceascribelineontheshrudandhraaeahstabilirlca'Thescribelineshallbemidwaybetweenthelugsontheshroudascontrolledbythescribetool.Thisscribelinewillbethelocatingreferenceforthe
0@'5A5585SHNO.6REV.4slotsintheshroudhead.Measureandrecordtheoutsidetooutsidedistance"S".NotethattheSHBlugsarenotstraddled,asinplantswithjetpumps.Thesestabilizersareplacedin-betweensetsofSHBlugs.6.3Go-gagechecksshallbeperformedontheshroudflangeandsteamdamforfit-upwiththeUpperSupport(alsocheckforpossiblepriordamagetothesteamdam).6.4Measureandrecordtheannuluswidthatthetopguidesupportringandthecoresupportringelevationsasshownonthe107E5679,Modification.drawing..ExaminetheRPVandshroudcontactsurfacestoassurethattherearenoabruptdiscontinuities;ifso,EDMspotfacetheseareasflush.Intakingthesemeasurements,atoolsimulatingthepiecepartwillbeusedtoassureproperfootprintcontact.6.5MeasureandrecordthedistancebetweentheCorePlateandtheShroudateachCorePlateSpacerlocation.6.6Basedonthein-reactormeasurements,machineCorePlateSpacer,112D6617,asshownontheModifiicauondrawing,107E5679.Thiswillleaveatotalclearancebetweentheshroud,spacer,andcoreplateof.020to.030in.6.7Basedonthein-reactormeasurements,machinepart112D6570,LowerWedge,and112D6571~~~LowerContact,asshownonthe107E5679Modificationdrawing.AssembletheLowerWedge,andLowerContactasshownontheTieRodSpringAssembly,drawing112D6546,exceptrotatethewedge180'utofpositionforinstallation.6.8Basedonthein-reactormeasurementsattheupperspringlocation,machineparts112D6577,UpperContact,and112D6565,UpperWedge,asshownonthe107E5679Modificationdrawing.AssembletheUpperContactandUpperWedgeasshownontheUpperSpringAssembly,drawing112D6574.6.9Machine(EDM)slotsintheshroudheadflangeasspecifiedonthe107E5679Modificationdrawing.AligntheEDMtoolingtothescribelinetoatoleranceofa.060.6.10Inaccordancewiththe107E5679Modificationdrawing,machine(EDM)two(2)holes,4.075.015in.dia.(holesizeafterhoning),inshroudsupportskirtateachofthefourStabilizerpositions.EDMswarfshallbecapturedtothemaximumextentpractical.6.11HonetheholesintheInconel600shroudsupport,toassuretheremovalofmicrofissuresfromtheEDMholes.Thehoningoperationshallremoveaminimumof0.004inchfromtheinsidesurfaceoftheholewhilemeetingthefinalholesizerequirement.Theminimumrequiredmaterialremovalwillcorrespondwithabrightsurfacefinish.6.12DELETED6.13DELETED6.14DELETED6.15DELETED
OO25A5585SHNO.7REV.46.16DELETED6.17.InstalltheLowerSupportAssembly,112D6576intotheholesintheshroudsupportconeper107E5679,Modificationdrawing,andtorquenutsto40+5ft-lbs,inaprogressivesequenceofapproximately10ft-lbincrements.6.18.Installlockingnut,torqueto30+10ft-lbs,andcrimpsleeveintogroovesontogglebolt.6.19AfterinstallationoftheLowerSupportAssembly,measurethedistancetothe,vesselwallatthemidsupportlocation.Basedonthisin-reactormeasurement,machinethetwocontactsurfacesofthemidsupport,112D6566,inaccordancewiththerequirementsofthe107E5679ModificationDrawing.6.20InstallSpacers,262B1285,undertheTopSupporttoobtainproperclearanceundertheTopGuideSupportFlange.ThedimensionspertheModificationDrawingwillresultinaclearanceof0.50to1.00inch.CAUTION:ManeuveringoftheTieRodSpringAssemblymustbedonewithextremecaretoavoiddamagingreactorhardware.6.21InstalltheTieRodSpringAssembly,112D6546,inaccordancewiththerequirementsofthe107E5679,Modificationdrawing.ManeuvertheclevispinunderthehookontheLowerSupport,and~~~~~~~holdinplace.RotatetheTopSupport,112D6588totheinstalledposition.6.22AdjusttheCenteringStudsontheUpperSupportperthedimensionalrequirementsontheModificationdrawing,107E5679,andcrimpthelockingnutstosecuretheproperspacing.Theresultingclearancewillbe0.015+.003oneachside.6.23PositiontheUpperSupportAssembly,112D6573,overthetierod.HangtheUpperSupportAssemblyoverthesteamdamandcenterbetweenshroudheadboltlugs.6.24Removethetemporarythreadprotectionfromthetierod.Installthetierodnutandtorqueto17515ft-lbs.Forcetheupperendofthetierodradiallyinwardduringtensioning.ChecktheLockingLatchontopofthenutforpropergrooveengagement.6.25DeflecttheLowerSpring,112D6568,awayfromthevesselwall,androtatetheLowerWedge,112D6570,180'ndslideituptheguidepinuntilthelatchengagesintheinstalledposition.Visuallycheckforproperlatchengagement.6.26SpringtheTieRodawayfromthevesselapproximately0.25in.toallowinstallationoftheMidSupport.TheMidSupportwilllatchintoanotchintheringontheTieRod.Visuallycheckforproperlatchengagement.VisuallyconfirmthatcontactexistsbetweenthemidsupportandtheRPVwall.Visuallyconfirmagapgreaterthan0.37inchesandlessthan0.75inchesexistsbetweenthemidsupportandtheshroud.6.27InstallUpperSpringAssembly,112D6574,inaccordancewiththerequirementsofthereactorModificationdrawing.EngagewithUpperSupportAssemblyandconfirmthatLatcheshavelockedoverpins.RotatethejackingboltuntiltheUpperWedgecontactsthevesselwall,approximately28turns(.25in.gap).Preloadtheupperspringanadditional822turns.(.072.02in.)asspecifiedon
025A5585SHNO.8REV.4the107E5679Modificationdrawing.Checkthatthespringretainershaveproperlylockedtheheadofthejackingboltafterthetoolisremoved.6.28InstalltheCorePlateWedges,112D6618,infourplacesandtorquethejackingboltto7-10ft-lb.Checkthatthespringretainershaveproperlylockedtheheadofthejackingboltafterthetoolisremoved.Ifretainersarenotlocked,thetorquemaybeincreasedtoreachthenextsetofnotches.6.29InstallaBottomSpringSpacer,.148C6912POOl.on.the.stabilizer.lower,springsat90degrees,at166degreesandat350degreesperModificationDrawing107E5679.VisuallychecktoassuretheBottomSpringSpacerclampingsurfacesareagainst(zeroclearance)thelowercontactandthatthestepattheendsofthelegsareengagedunderthelowercontact.7.EXAMINATIONANDTESTING7.1VisualExaminatin.Visuallyexaminetheinstalledstabilizerstoverifycompliancewiththe107E5679ModificationDrawing.8.RECORDSANDSUBMITTALS8.1Priortoimplementationofthisstabilizerinstallationprogram,thefollowingproceduresshallbesubmittedbytheInstallerandapprovedbytheOwner.a.Installationandinspectionproceduresincludingsequencedatasheets,measurementdatasheets,qualitycontrolchecksheets,drawings,sketches,instructions,etc.b.Cleaningandcleanlinesscontrolprocedures.Machiningproceduresasapplicable.8.2Afterimplementationofthisstabilizerinstallationprogram,allrecordeddatarecords,photographs,videotapes,etc.,shallbesubmittedbytheInstallertotheOwnerforfileandinformationwithin30days.The107E5679modificationandinstallationdrawingshallbeupdatedtoincorporatethein-reactoras-builtmeasurements,withcorrespondingserialnumbersofthepartsmachinedaspartoftheinstallationprocess.OnecopyshallbesubmittedtoGENEwithin30days.
GENucfear25A5585SHNO.9REV.4FINAL9.DEVIATIONSANDSUBSTITUTIONS9.1Alldeviations,asaresultofdamagedequipment,nonconformingconditions,oranyproposalbytheInstallerforsubstitutions,modifications,orrelaxationofthespecifiedmaterials,proceduresordesignshallbesubmittedtotheOwnerforconsiderationandapproval.
ENCLOS2SARYOFNMPC10CFR50.59SAFETYEVALUATION
Enclosure210CFR50.59SafetyEvaluationSummary(Criteria,ConformancekReferences)ANALYSISTheapplicablecriteriaandconformanceforthisanalysisisasfollows.ThecriteriaisthesamecriteriathatwasusedfortheoriginalShroudRepairDesignSafetyEvaluation,Reference23.Theconformancesectionsspecificallyaddressthetwoproposedmodifications.DesignLife(Criteria)Thedesignlifeofallrepairhardwarewillbefortwenty-fiveyears(theremaininglifeoftheplant,pluslifeextensionbeyondthecurrentoperatinglicense),toinclude20EffectiveFullPowerYears.ReairDesinLifeConformanceThehardwareforthetwomodificationsisfabricatedtothesamedesignbasis,includingmaterialrequirements,astheoriginalshroudrepairhardware.Allrepairhardwarehasbeendesignedforadesignlifeoftwenty-fiveyears(theremaininglifeoftheplant,pluslifeextensionbeyondthecurrentoperatinglicense),toinclude20EffectiveFullPowerYears.Thisrequirementisdocumentedinreferencel.Assuringanadequatedesignlifeismainlyamaterialselectionandprocesscontroleffort,forthisequipment.Theselectionoflowcarbonstainlesssteelsandhighnickelalloysassuresthebestavailablematerialsforthenuclearreactorenvironment.SolutionannealingandsensitizationtestingareimposedtoguardagainstintergranularstresscorrosioncrackinggGSCC).Processchemicalcontrolsareimposedtoassurethatcontaminationbyheavymetalandchlorineorsulfurcompoundswillnotoccur.Thisisthesamedesignselectionsandcontrolsimposedforastandardfortyyearplantlife.Thereisnothingintheequipmentorinstallationthatputsaspecificlimitonhowlongitcanbeused,suchascreeporradiationdegradation.SafetyDesignBasis(Criteria)Toassurethesafetydesignbasisissatisfiedandthatthesafeshutdownoftheplantandremovalofdecayheatarenotimpaired,therepairhardwareshallassurethatthecoreshroudwillmaintainthefollowingbasicsafetyfunctions:
~TolimitdeflectionsanddeformationtoassurethattheEmergencyCoreCoolingSystems(ECCS)canperformtheirsafetyfunctionsduringanticipatedoperationaloccurrencesandaccidents.~Maintainpartitionsbetweenregionswithinthereactorvesseltoprovidecorrectcoolantdistribution,forallnormalplantoperatingmodes.~Providepositioningandsupportforthefuelassemblies,controlrods,incorefluxmonitors,andothervesselinternalsandtoensurethatnormalcontrolrod-movementisnotimpaired.SafetDesinBasisConformanceThechangesinthelowerspringspacingaffectsthesystemspringcharacteristicsforloadsactingbetweentwocontacts.Additionalseismicanalysis(Reference24)calculatedcoresupportdisplacementsfortheboundingconditions.Thesectionbelowisrevisedtoincludethemaximumdisplacementsbasedonmodifiedlowerspringspacingandincludesthegapbetweentheshroudandthecontactextension.Alldisplacementsremainacceptable.~Thecorespraypipinganalysisperformedtosupporttheshroudrepairincludedashrouddisplacementof0.904in.horizontallyand0.65in.vertically,causedbyafaultcondition.ThisdisplacementwillnotcreateanunacceptableloadingconditionintheECCSpipingandthereforewillperformitsintendedsafetyfunction.Theproposedmodificationsdonotchangethemaximumdisplacementscalculatedfortheoriginalshroudrepairattheuppershroud.Thereforethereisnochangeinloadingofthecorespraypiping.~Theproperdecayheatremovalrequiresthattheshroudtoremainasaflowboundarytoforcewaterthroughthefuelandnotallowalargeleakageintothedowncomerregion.Themaximumpermanenthorizontaloffsetofadjacentshellsections,thatarenotdirectlysupportedbyeithertheupperorlowersprings,islimitedbystructuralstopsto0.75in.Sincethewalloftheshroudis1.5in.thick,theshroudwillstillfunctionproperlyasaflowboundarywithinthereactor.~ThesafeshutdownoftheplantisafunctionoftheSCRAMcapability.Thecoresupportplateandthetopguidemustbekeptalignedwithintestlimitssothatfrictionbetweenthecontrolrodsandfuelbundleswillnotimpairpropermotion.Theworstcaseconditionexistswhenthetopguidemovesonedirectionandthecoresupportmovestheopposite.Thiscreatesthemaximumanglebetweenthefuelbundlesandtheguidetubes.Themaximumtemporarycalculatedhorizontaldisplacementofthetopguideis0.904in.andthemaximumforthecoresupportis0.85in.Thecorrespondingallowabledisplacementare1.87in;and1.49in.'hereisnocalculatedpermanent llI horizontaldisplacementofthetopguideandthemaximumpermanentdisplacementforthecoresupportis0.48inches.Thecorrespondingallowablecoresupportpermanentdisplacementsis0.67inches.FlowPartition(Criteria)Repairstothecoreshroudarenotrequiredtototallypreventleakagefromthecoreregionintothedowncomerannulus.However,thedesignshallensurethatcrackedweldsdonotseparateundernormaloperationsasaminimum.Designwillaccountfor,leakagefromtheregioninsidetheshroudintotheannulusregionduringnormaloperation..Theleakageshouldnotexceedtheminimumsubcoolingrequiredforproperrecirculationpumpoperationandthecorebypassflowleakagerequirementsassumedinthereloadsafetyanalysisshallbemaintained.Thedesignwillalsoverifyacceptableleakagethroughtheflowpartitionresultingfromweldseparationduringaccidentandtransientevents.FlowPartitionConformanceTheoriginalshroudrepairdesignensuredthatcrackedweldswillnotseparateundernormaloperations.Theoriginalshroudrepairdesignaccountedforleakagefromtheregioninside.theshroudintotheannulusregionduringnormaloperation.Theleakagedoesnotexceedtheminimumsubcoolingrequiredforproperrecirculationpumpoperationandthecorebypassflowleakagerequirementsassumedinreloadsafetyanalysesismaintained..Therearenorequirementsforallowableleakageduringtheaccident(LOCAand/orseismic).Aftertheaccident,theleakageislimitedbytheallowabledeflectionssuchthattheshroudsectiondoesnotdisplacesufficientlytoopenanyverticalflowareas.Themaximumpermanenthorizontaldisplacementofashroudcylindricalsectionthatisnotdirectlysupportedbyeithertheupperorlowerspringsislessthan0.75inch,whichisequaltoonehalfofthethicknessoftheshroud.Thus,leakageafteranaccidentwillbelimitedtotheleakagethroughacrack.Sincethepressuredifferenceacrosstheshroudissmall,theleakagewillbesmall.Thetwoproposedmodificationshavenoaffectonthepotentialweldcrackseparationoranypotentialleakagepath.Thetwomodificationsdonotrequireanynewholesorpenetrationsthroughtheshroud/shroudsupport.ThereforetheleakagecalculationsandperformancepredictionsinReference23remainvalid.Theaddedcontactextensionprovidesassurance'themaximumpermanentdisplacementoftheshroudcylinderbetweenweldHSandH6Aremainslessthan0.75inch.FlowInducedVibration(Criteria)Therepairshallbedesignedtoaddressthepotentialforvibration,andtokeepvibrationtoanacceptablelevel.Thenaturalfrequencyoftherepairedshroud,includingtherepair
hardware,shallbedetermined.Thevibratorystressesshallbelessthantheallowablestressesoftherepairmaterials.Forcingfunctionstobeconsideredincludethecoolantflowandthevibratoryforcestransmittedviatheendpointattachmentsfortherepair.Testingmaybeusedasanalternativeortosupplementthevibrationanalysis.FlowInducedVibrationIConformanceTheoriginalshroudrepairwasdesignedtoaddressthepotentialforvibration,andtokeepvibrationtoaminimum.Thenaturalfrequencyoftherepairedshroud,includingtherepairhardware,hasbeendetermined.Theusagefactorduetocyclicstressescausedbyvibrationwillbelessthan1.0forthedesignlifeoftherepairhardware.Forcingfunctionsconsideredincludedthecoolantflowandthevibratoryforcestransmittedviatheendpointattachmentsfortherepair.DetailsoftheoriginalvibrationanalysisareprovidedinReference23.ThetworepairmodificationshavenoafFectonthenaturalfrequencyofthestabilizerassemblyoronthevortexsheddingfrequency.ThereforetheoriginalvibrationevaluationinReference23remainsvalidforthestabilizerassemblies.Thepotentialforvibrationofthenewextensionpieceshasbeenconsidered.Forcingfunctionsconsidered,includedthevibratoryforcestransmittedfromthestabilizerassembliesandcoolantfiow.Thestabilizervibratoryforcesarelow,asdemonstratedintheoriginalvibrationanalysis,thereforevibratoryforcesimposedontheextensionpiecesarelow.Thecoolantfiowwillnotvibratethelowercontactextensionsbecausetheextensionsarecapturedinalldirectionsontheexistinglowerspringassembly.Thelowercontactextensionisa"U"shapedpartwhichfitsaroundtheexistinglowercontact.Stepsattheendsofitslegsextendunderthelowercontacttopreventaxialmovement.Atangtowardsthe'topfitsinthegapbetweenthelowercontactandthelowerspringtopreventhorizontalmovement.Apositivespringforcefromthelegskeeptheparttightandpreventrandomvibrations.LoadingonExistingInternalComponents(Criteria)Increasedstressonexistinginternalcomponents,usedintherepair,isacceptableaslongasthecurrentplantlicensingbasisaremet.Increasesinappliedloadshallbedemonstratedtobeacceptable.~Therepairshallbedesignedsoastoproduceacceptableloadingontheoriginalstructureoftheshroud,consistentwiththecriteriaprovidedherein.~Therepairshouldminimizestressesintroducedintotheshroudconsistentwiththecriteriaprovidedsoastonotaggravatefurthershroudcracking.Therepairshouldminimizetheloadingonthesupportingstructuresoftheshroud,suchastheshroudsupportconeandtheRPVwall,tostaywithintheoriginaldesignallowablestressesofthesestructures.
k
~SupplementalseismicanalysisfortheproposedmodificationsshallconformtothesamemethodologyandcriteriausedintheoriginalshroudrepairseismicanalysisasdocumentedintheFSAR.LoadinonExistinInternalComonentsConformance~Stressesontheoriginalstructureoftheshroud,whicharedirectlyimpactedbytheshroudrepairhardware,havebeendemonstratedtobeacceptable.Theresultsofthisevaluationaredocumentedinreferences4,5andl.l.forall.of.the.postulatedaccidents.~Theoriginalshroudrepairwasdesignedtominimizestressesintroducedintotheshroudconsistentwiththecriteriaprovidedsoastonotaggravatefurthershroudcracking.Theadditionofthecontactextensionsandthemodificationtothe270'ierodhasaninsignificantaffectonthecomponentloadsandstresses.ThereforetheevaluationinReference23remainsvalid.~Theoriginalshroudrepairdesignminimizedtheloadingonthesupportingstructuresoftheshroud,suchastheshroudsupportconeandtheRPVwall,tostaywithintheoriginaldesignallowablestressesofthesestructures.Theresultsofthisevaluationaredocumentedinreferences4,5and11forallofthepostulatedaccidents.Relocatingthe270'owerspringassemblychangesthespacingbetweentheadjacentlowerspringassemblies.Thechangeinspacingaffectsthenetspringcharacteristicsandloaddistributionwhentwospringssharethehorizontalseismicload.Analysisshowtheloadonanyonespringdoesnotexceedtheloadsusedintheoriginalstressevaluation,Reference24.Thestressevaluationremainsvalidforthemodified270'tabilizermodification..SeismicAnalsisConformanceThemodificationaddingthecontactextensionshasnoaffectontheseismicanalysis.Relocatingthelowerspringaffectstheoriginalseismicanalysis.Supplementalseismicanalysiswasmadeusingthesamemethodologyandcriteriaaswasusedintheoriginalseismicanalysis.Thechangesinthespacingbetweenlowerspringsandaffectstheeffectivespringcharacteristicswhentwospringssharethehorizontalseismicloads.Springslessthan90'partincreasetheeffectivespringconstantandspringsgreaterthan90'endtolowerthespringconstant.Equivalentspringconstantsweredeterminedfortheboundingconditionsandadditionalseismiccalculationsweremadetodetermineloadsanddisplacements(Reference24).Theindividualspringloadsdonotexceedtheloadsusedintheoriginalstressevaluation(Reference25)andthecalculateddisplacementsremainacceptable.
AnnulusFlowDistribution(Criteria)Thedesignshallnotadverselyaffectthenormalflowofwaterintheannulusregion,orthenormalbalanceofflowinthisregion.Thedesignshallnotadverselyrestricttheflowofwaterintotherecirculationsuctioninlet.AnnulusFlowDistributionConformanceNeitherofthetwomodifications"adverselyaffectthenoimalflowofwaterintheannulusregion,orrestricttheflowinanywaythatwouldadverselyaffectnormalbalanceofflowinthisregion.Thedesigndoesnotadverselyrestricttheflowofwaterintotherecirculationsuctioninlet.EmergencyOperatingProcedure(EOP)Calculations(Criteria)InputstotheEOPcalculations,suchasbulksteelresidualheatcapacityandreductionofreactorwaterinventoryshallbeaddressedbasedonrepairhardwaremassandwaterdisplacement.Emerenc0eratinProcedureOPCalculationsConformanceTheadditionofthespringcontactextensionshaveaninsignificantaffectontheEOPcalculations,suchasbulksteelresidualheatcapacityandreductionofreactorwaterinventorysincethequantityofsteeladdedisnegligibleascomparedtothemassandvolumeoftheexistingshroudrepairhardwareandreactorinternals.RadiationEffectsonRepairDesign(Criteria)Thedesignoftherepairshallaccountfortheaffectsofirradiationrelaxationutilizingend-of-lifefluenceonthematerials.RadiationEffectsonReairDesinConformanceTheoriginaldesignoftherepairaccountsfortheaffectsofirradiationrelaxationutilizingend-of-lifefluence'onthematerials.InaccordancewithReference1,thedesignconsidersanEnd-of-Lifepreloadrelaxationfortheupperandlowersprings.TheradiationlevelislessthanthelimitcontainedintheUFSAR.Thebasisforthisisdocumentedinreference11(designbasisforreference1).Thecontactextensionhasapositivespringloadedclampingforcearoundthelowercontact.Theinitialinstallationclampingforceisnotrequiredtokeepthepartcapturedorfortheparttoremainfunctional.Radiationrelaxationmayreduce,butwillnoteliminatethepositiveclampingload.Apostulatedreductionintheinitialclampingload
duetoradiationrelaxationisnotaconcernbecausetheextensionpiecesarecapturedinalldirectionsasdiscussedpreviouslyandanyamountofpositiveclampingloadwillpreventfreemovementorrandomvibrationsoftheextensionpieces.ThermalCycles(Criteria)Therepairhardwareshallconsidertheeffectsofthermalcyclesfortheremaininglifeoftheplant.AnalysisshalluseoriginalplantRPVthermalcyclediagrams.Thedesignshallassumeanumberofthermalcyclesequaltoorgreaterthanthenumberassumedin,theoriginalRPVdesign.Alternatively,thermalcyclesdefinedbyactualplantoperatingdatamaybeemployediftechnicallyjustified.Usingthisthermalcycleinformationrepaircomponentsandtherepairedshroudshallbeevaluatedforfatigueloadingalongwithanyotherdesignvibratoryloads.ThermalCclesConformanceTheoriginalshroudrepairhardwareconsideredtheeffectsofthermalcyclesfortheremaininglifeoftheplantasdocumentedinReference5.Thestressesresultingfromthethermalcycleshavebeenevaluatedbyafatigueanalysis.Theresultsshowthatitseffectonfatiguelifeoftheplantisnegligible.Thetwomodificationshaveaninsignificanteffectonpreviousfatigueanalysis.Chemistry/Flux(Criteria)ThedesignshallrecognizetheuseofexistingandanticipatedwaterchemistrycontrolmeasuresforBWRsandshallconsidertheaffectsofneutronfluxonanymaterialsusedintherepair.Chemist/FluxConformanceSincethematerialsforthetwomodificationsarethesameaswasusedfortheinstalledshroudrepairhardware,existingandanticipatedwaterchemistrycontrolmeasuresandtheaffectsofneutronfluxonthematerialshavebeenaddressedandwillhavenoeffectontherepairhardware.LoosePartsConsideration(Criteria)Repairhardwaremechanicalcomponentsshallbedesignedtominimizethepotentialforloosepartsinsidethevessel.Thedesignrepairshallusemechanicallockingmethodsforthreadedconnections.Allpartsshallbecapturedandheldinplacebyamethodthatwilllastforthedesignlifeoftherepair.P I'
LoosePartsConsiderationonformanceThemodifiedstabilizerassemblyhasbeendesignedtominimizethepotentialforloosepartsinsidethevessel.Thedesignrepairusesmechanicallockingmethods(suchascrimpedjamnuts)forthreadedconnections.Allpartsarecapturedandheldinplacebyamethodsuchaspinning,staking,springretainers,interferencefits,andcrimpingthatwilllastforthedesignlifeoftherepair.Thelowercontactextensioniscapturedinalldirectionsontheexistinglowerspringassembly..Thelower.contactextension.isa".U"shapedpartwhich.fits.aroundtheexistinglowercontact..Stepsattheendsofitslegsextendunderthelowercontacttopreventaxialmovement.Atangtowardsthetopfitsinthegapbetweenthelowercontactandthelowerspringtopreventhorizontalmovement.Apositivespringforcefromthelegskeeptheparttightandpreventrandomvibrations.Thespringforceisnotrequiredtoensuretheextensionissecuredtotheexistinglowercontact.LoosePartsGeneratedbtheReairProcessSpecialtooling/equipmentisbeingprovidedthatwillbetestedandpersonnelwillbetrainedonfullscalemockupstoassureadequatecontrolsexisttominimizethepotentialforvesselinternalsdamageorlooseparts.ProtectiveshieldshavebeendesignedthatcanbeinstalledasneededtoprotecttheFeedwaterSparger,CoreSprayLineandtheRecirculationnozzles.NMPCandGEinstallationprocedures/travelerswillbeusedtoestablishForeignMaterialExclusion(FME)controls.AlltoolsandequipmentusedintheVesselandSpentFuelPoolwillbeproperlysecured.InspectionAccess(Criteria)Therepairdesignshallbesuchthatinspectionofreactorinternals,reactorvessel,ECCScomponentsandrepairhardwareisfacilitated.Theinstalledrepairhardwareshallnotinterferewithrefuelingoperationsandshallpermitservicingofinternalcomponents.Allpartsshallbedesignedsothattheycanberemovedandreplaced.Thisistoprovidefullaccesstotheannulusareaforotherpossiblefutureinspectionsand/ormaintenance/repairactivitiesthatmayprovenecessaryinthefuture.InsectionAccessConformanceNeithermodificationafFecttheaccessforinspections.Allpartshavebeendesignedsothattheycanberemovedandreplaced.
Crevices(Criteria)Therepairdesignshallbereviewedforcrevicestoassurethatcriteriaforcrevicesimmunetostresscorrosioncrackingaccelerationaresatisfied.CrevicesConformanceTheselectionofthematerialsforthemodificationhardwareisthesameastheoriginalhardwareandassuresthatcriteriaforcrevicesshowntobeimmunetostresscorrosioncrackingaccelerationaresatisfied.Materials(Criteria)AllmaterialsusedshallbeinconformancewiththeBWRVIPrequirements.v'aterialsConformanceMaterialsforthetwomodificationshavethesamerequirementsastheoriginalshroudrepairhardwareandareinconformancewith'theBWRVIPrequirements.Maintenance/Inspection(Criteria)Thedesignedrepairshallminimizetheneedforfutureinspectionsandmaintenanceoftherepaircomponents.Thedesignedrepairshallminimizetherequirementforfutureinspectionsoftheaffectedshroudjoints.Maintenance/Inspection(Conformance)NeithermodificationhasanaffectonconformancetotheMaintenance/Inspectioncriteria.InstallationIssues(Criteria)Tooling/equipmentusedforinstallationofrepaircomponentsshallbeevaluatedinaccordancewithReference9andshallconsiderthefollowing:~Heavyloads~ShutdownSystemStatus(N+1)~Rigging~HoleCuttingMethod
InstallationIssuesConformanceThemodifiedstabilizerassemblyhasthesameinstallationrequirementsastheoriginalstabilizerassembly.Noholecuttingisrequiredforeithermodification.Theinstallationactivitiesassociatedwiththeproposedmodificationswillbeevaluatedinaseparatesafetyevaluation'(Ref.26).ExistingReactorInternals(Criteria)Thedesignshallnotrelyonexistingreactorinternalsorcomponentstocarryloadsthathaveexperiencedcrackingintheindustry(e.g.shroudheadboltlugs,stubtubes).ExistingReactorInternals(Conformance)Neithermodificationreliesonexistingreactorinternalsorcomponentstocarryloadsthathaveexperiencedcrackingintheindustry(e.g.shroudheadboltlugs,stubtubes).REFERENCES1.GE-NESpecification:25A5583,Rev.2,"ShroudRepairHardware,DesignSpecification"2.GE-NESpecification:25A5586,Rev.1,"ShroudRepairCode,DesignSpecification"3.UFSAR,Rev.12,NineMilePoint14.GE-NEDocument:24A6426,Rev.1,"ReactorPressureVesselStressReport"5.GE-NE-B13-01739-04,Rev.0,"ShroudRepairHardwareStressAnalysis"6.GE-NE-B13-01739-03,Rev.0,"SeismicDesignReportofShroudRepairforNineMilePoint1NuclearPowerPlant"7.NRCGenericLetter94-03,July25,1994,"IntergranularStressCorrosionCrackingofCoreShroudsinBoilingWaterReactors"8.NiagaraMohawkProcedure:Nl-MMP-GEN-914,"LiftingofMiscellaneousHeavyLoads"9.GE-NESpecification:386HA852,"ReactorServicingTools"10.GE-NEDocument:NEDO-10909,Rev.7,"SAPG07,StaticandDynamicAnalysisofMechanicalandPipingComponentsbyFiniteElementMethod"
11.GE-NEDocument:DRFB13-01739,"NineMilePoint1ShroudStabilization"12.GE-NEProcedure:NM-SM-TP&P-04,"EDMActuators"13.NiagaraMohawkProcedure:N1-ODG-11,"OutageSafetyAssessment"14.NiagaraMohawkProcedure:NIP-OUT-01,"ShutdownSafety"15.GE-NE,"PostInspectionPlan"16.GE-NESpecification:21A1104,Rev.0;"SpecificatioiiforReactorPressure'Vessel"17.BWROGVIPCoreShroudRepairDesignCriteria,Rev.1,September12,199418.GE-NESpecification:25A5584,Rev.1,"FabricationofShroudRepairComponents"19.GE-NEDrawing:237E434,Rev.5,"ReactorVesselLoadings"GEDrawing20.GE-NESpecification:383HA718,ThermalCycles,ReactorVesselandNozzle,DescriptionBasisandAssumptions21.GE-NE-A0003981-1-13,Rev..l,"PerformanceImpactofShroudRepairLeakageforNMP1",12/15/9422.NiagaraMohawkDocument:SO-EOP-M018,23.GE-NE-B13-01739-05,Rev.1,SAFETYEVALUATION,GECoreShroudRepairDesign,24.Supplement1,GENE-B13-01739-03,Rev.0,NineMilePoint1,SeismicAnalysis,CoreShroudRepairModification25.Supplement4,GENE-B13-01739-04,NineMilePoint1,ShroudRepairHardwareStressAnalysis26.NMPCSafetyEvaluationNo.95-007Rev.1,NineMilePoint1,CoreShroudRepairInstallation.