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{{#Wiki_filter:}} | {{#Wiki_filter:ATTACEKNTPage1of6TERMINATIONMODULEFINALRESOLUTIONConductorInsulationDamageofT-HODSLocatedInTerminationCabinets.ThePowerGenerationControlComplex(PGCC)isdevelopedandsuppliedbyGeneralElectricundertheH-1NSSScontract.ThePGCCusesterminationcabinetstointerfacebetweenfieldcables.Mostcablesinterfaceonaterminationmodule(T-HOD)whichconsistsofanANconnectorforthecablefromthePGCCfloorsectionandaterminalboardfor.theincomingfieldcable(seeattachedFigs.3-4,3-5,and3-6).NCR3030wasissuedonSeptember28,1978toidentifydamagedconductorinsulationwithintheT-MODconnectinganANconnectorandtheterminalboard.ThedamageswerefirstobservedduringanimplementationofreworkofterminationcabinetITC-621attheSSESsite.Ofthe-total450T-MODunitsforSSESUnit1,127unitswerefoundtoexhibitoneormoreofthefollowingdefects:1)Severeindentationsontheinsulation(noexposedwire).2)Abrasion(scuffing)oftheinsulation(noexposedwire).3)'Nicksanddings'ntheinsulation;i.e.,minor1/32"to1/8"long)lateralandlongitudinalcuts(exposedwire).4)Severelongitudinalgouging.Hirewasexposed(1/8"to1/2"long)andthegougedinsulationindicatedsharpedgecuttinginbothdirections.GeneralElectric'sQAverificationprocedureforthemanufacturingprocesswasinsufficienttodetectthedamageinsulation.CauseItwasdeterminedbyGEthat95%ofthedamagedunitswereHi-DensityTerminationModules(21and48pinassemblieswhichusetwistedshieldedpairandtriplecables-20awgwirewithferruleterminationsontheshields).Duringthereassembly(i.e.,pininsertionandextractionusingthestandardAmphenoltoolingoftheterminationmodules)continualdifficultywasobserved.Theferruleedgeduringextraction,andthesharpinsertiontooledgeduringassembly,impactedonthedenselypackedwiresattheconnectorarea.Furtherdamage(3abrasionsoutof900con-ductors)wasobservedduringthereassemblyoperation.Theassembledunitswerethenre-inspectedandthethxeeaddeddefectswerenoted. | ||
ATTACEBKHTPage2of6ItwascausedItwasofonemoduledamageother.alsonotedthatthesharpedgesoftheterminationmoduleframesindentationsonthewire.insulationofimproperlystackedunits.seenthatthiswascausedbythesharpedgeofthesteelframemodulelaidagainsttheunprotectedwirebundlesofanadjacentHandlingprecautionsarerequiredtopreventthistypeofsinceitcanpotentiallyoccuranytimetwomodulescontacteachInsummary,thepossiblecauseofinsulationdamagecanbeattributedto:1)2)3)ImproperAssembly-PinInsertion/ExtractionHandlingandStorageProducibility-Hi-Densitymodules-Conductorfreelength-FerruleconceptAnalsisoftheSafetImlicationsThesystemdesignwasreviewedandthefollowingwasconcludedfortheworstcondition.TheinsulationdamageoftheT-MODsvariesfrombarelyvisibletotheunaidedeyeto1/2"exposedbarewire.Althoughnoinsulationbreakdownwasobservedduringthehi-pottesting(standard2.2KVDC)ofindividualconductorstoconnectorshellandotherpinsofthesameconnector,thefrequencyofoccurrenceissuchthatifthedefectswereleftundetected/uncorrected,shortingofconductorsmustbeassumedpossible.SomeoftheaffectedsystemsareRHR,RCIC,andCorespray.LossofT-MODconductorsmaypreventthecircuitsfromperformingtheirdesignedsafetyrelatedfunctions.Suchaneventualitypresentsanunacceptableconditioneventhroughtheremayberedundantsubsystemsremainingunaffected.InadditionGeneralElectric'sQAprogramhadfailedtodetectanydefectsduringthemanufacturingprocess.ProjectEngineeringhasdeterminedthePGCCT-MODsdeficiencytobereportableunder10CFR50.55(e).CorrectiveActionSAllUnit1defectiveunitshavebeenreturnedtoGESanJoseforrework.Toprecludere-occurrenceonthereworkofUnit1T-NODS,thefollowingactionshavebeentakenbyGE:l.ImproperAssemblyThemethods,planningprocess,andoperatortraininghavebeenupgradedsincetheSusquehannaIT-MODSwerebuiltinthefirstquarterof1976.This,withtheproducibilitychanges,willminimizedifficultiesobservedduringthereassemblyoperationsforT-Mods.GeneralElectric'squalityprogramappliedtotheUnitIterminationmoduleswasdefectiveinonemajorarea.Thein-processinspectionsystemdidnotincludethephysicalinspectionofthepininsertionprocess.(Theassumptionthatcontinuityandinsulationtestingwoulddetectallfunctionallysignificantinsulationdamagehasnotbeenconfirmed).Addedin-processinspectionpointsandareviseddetailed.inspection.-planhavebeenaddedtotheassemblyoperationoftheT-Mods. | |||
ATTACE4EIQ'Page30I62.HandlingandStorageOperatortraininginthehandlingofT-Modswithproperphysicalseparationand,stackingwillreduceobservedproblemsinthisarea.Inaddition,theT-Mods,whencomplete,willbestyrofoamwrappedandtapedtoprecludestorageandshippingdamage.(Thispracticewasimplementedinearly1977.)3~ProducibilityOntheUnitIreworkoftheT-Nods,severalproducibilitychangeswhichhavebeenimplementedonsubsequentprojectswillbeapplied:a.Tensolitewirewhichislesssusceptible,toabrasionand'dinging'illbeappliedtoreworkedT-Mods.b.AnalternatemethodofshieldingwhichdoesnotrequiretheferruleconceptwillbeappliedtoreworkedT-mods.c.LongerfreeconductorlengthforeaseofassemblywillbeappliedtoreworkedT-Nods.ConclusionTherepair/reworkandre-testoftheT-NODSforSSESUnit1hasbeenaccomplishedperGEproceduresandcriteria.Thedeficiencyhasnowbeencorrectedandthepotentialsafetyhazardhasbeeneliminated.TheSSESUnit1reworkedT-Nodsh'avebeenshippedandinstalledatthejobsite.AportionoftheUnit2T-NodsweremanufacturedinthesametimeperiodastheUnit1T-Mods.InspectionwillbeperformedatSSESperaGEdocumentFDIMDBC.DefectiveunitswillbereturnedtoGEforrepairbeforefuelload.GEfabricationpersonneltraining,.inspectionandrevisedfabricationtechniqueshasprecludedreoccurrenceofsimilarproblemsontheremainingUnit2T-Nods.TheinspectionstobeconductedinaccordancewithFDIMDBCincludea100$visualinspectionofterminalstripsforcracked.,brokenormissingbarriersandconductorinsulationfornicks,abrasionandcuts.Theexistenceofanyoftheseconditionsiscauseforrefection.SK:po2873 QAYAREDO50455OASISbAXPdtGAY0L%th'3.08420ATTACKZNTPage4of6l,r)~taTKNWOVLKGAYCtarviaDAf5nERBAYDtIihR~i'>~lJOARRCRCONIECTOR~TE$TATlONARYQAttltlERSFUXRFlATKt4PPCltTFCSTAgee04,AssembledTarnationCo%~(Doomremovodlotch~-~~reels~iai~p~'pie~eI~~O~iii'".S~~a'~iver~.a:'S''r | |||
'sA"208420ATTACHMEHTPage5ofI~~~~y~y~~CCNNECTO'asmuoM~~817 HED0.10468'TTACHi~ITPage6of6v~~vIrv'(IPrvfILLSCASLC0000~~o~i'000~~~~~~1~~~o'~~~~~~~~~~V~~~~~~~~~~0lPt>.~~~I~~~~~~~4VNCTlOMSOX | |||
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Revision as of 09:41, 20 April 2018
ML18031A343 | |
Person / Time | |
---|---|
Site: | Susquehanna |
Issue date: | 01/08/1980 |
From: | PENNSYLVANIA POWER & LIGHT CO. |
To: | |
Shared Package | |
ML18031A342 | List: |
References | |
NUDOCS 8001150438 | |
Download: ML18031A343 (7) | |
Text
ATTACEKNTPage1of6TERMINATIONMODULEFINALRESOLUTIONConductorInsulationDamageofT-HODSLocatedInTerminationCabinets.ThePowerGenerationControlComplex(PGCC)isdevelopedandsuppliedbyGeneralElectricundertheH-1NSSScontract.ThePGCCusesterminationcabinetstointerfacebetweenfieldcables.Mostcablesinterfaceonaterminationmodule(T-HOD)whichconsistsofanANconnectorforthecablefromthePGCCfloorsectionandaterminalboardfor.theincomingfieldcable(seeattachedFigs.3-4,3-5,and3-6).NCR3030wasissuedonSeptember28,1978toidentifydamagedconductorinsulationwithintheT-MODconnectinganANconnectorandtheterminalboard.ThedamageswerefirstobservedduringanimplementationofreworkofterminationcabinetITC-621attheSSESsite.Ofthe-total450T-MODunitsforSSESUnit1,127unitswerefoundtoexhibitoneormoreofthefollowingdefects:1)Severeindentationsontheinsulation(noexposedwire).2)Abrasion(scuffing)oftheinsulation(noexposedwire).3)'Nicksanddings'ntheinsulation;i.e.,minor1/32"to1/8"long)lateralandlongitudinalcuts(exposedwire).4)Severelongitudinalgouging.Hirewasexposed(1/8"to1/2"long)andthegougedinsulationindicatedsharpedgecuttinginbothdirections.GeneralElectric'sQAverificationprocedureforthemanufacturingprocesswasinsufficienttodetectthedamageinsulation.CauseItwasdeterminedbyGEthat95%ofthedamagedunitswereHi-DensityTerminationModules(21and48pinassemblieswhichusetwistedshieldedpairandtriplecables-20awgwirewithferruleterminationsontheshields).Duringthereassembly(i.e.,pininsertionandextractionusingthestandardAmphenoltoolingoftheterminationmodules)continualdifficultywasobserved.Theferruleedgeduringextraction,andthesharpinsertiontooledgeduringassembly,impactedonthedenselypackedwiresattheconnectorarea.Furtherdamage(3abrasionsoutof900con-ductors)wasobservedduringthereassemblyoperation.Theassembledunitswerethenre-inspectedandthethxeeaddeddefectswerenoted.
ATTACEBKHTPage2of6ItwascausedItwasofonemoduledamageother.alsonotedthatthesharpedgesoftheterminationmoduleframesindentationsonthewire.insulationofimproperlystackedunits.seenthatthiswascausedbythesharpedgeofthesteelframemodulelaidagainsttheunprotectedwirebundlesofanadjacentHandlingprecautionsarerequiredtopreventthistypeofsinceitcanpotentiallyoccuranytimetwomodulescontacteachInsummary,thepossiblecauseofinsulationdamagecanbeattributedto:1)2)3)ImproperAssembly-PinInsertion/ExtractionHandlingandStorageProducibility-Hi-Densitymodules-Conductorfreelength-FerruleconceptAnalsisoftheSafetImlicationsThesystemdesignwasreviewedandthefollowingwasconcludedfortheworstcondition.TheinsulationdamageoftheT-MODsvariesfrombarelyvisibletotheunaidedeyeto1/2"exposedbarewire.Althoughnoinsulationbreakdownwasobservedduringthehi-pottesting(standard2.2KVDC)ofindividualconductorstoconnectorshellandotherpinsofthesameconnector,thefrequencyofoccurrenceissuchthatifthedefectswereleftundetected/uncorrected,shortingofconductorsmustbeassumedpossible.SomeoftheaffectedsystemsareRHR,RCIC,andCorespray.LossofT-MODconductorsmaypreventthecircuitsfromperformingtheirdesignedsafetyrelatedfunctions.Suchaneventualitypresentsanunacceptableconditioneventhroughtheremayberedundantsubsystemsremainingunaffected.InadditionGeneralElectric'sQAprogramhadfailedtodetectanydefectsduringthemanufacturingprocess.ProjectEngineeringhasdeterminedthePGCCT-MODsdeficiencytobereportableunder10CFR50.55(e).CorrectiveActionSAllUnit1defectiveunitshavebeenreturnedtoGESanJoseforrework.Toprecludere-occurrenceonthereworkofUnit1T-NODS,thefollowingactionshavebeentakenbyGE:l.ImproperAssemblyThemethods,planningprocess,andoperatortraininghavebeenupgradedsincetheSusquehannaIT-MODSwerebuiltinthefirstquarterof1976.This,withtheproducibilitychanges,willminimizedifficultiesobservedduringthereassemblyoperationsforT-Mods.GeneralElectric'squalityprogramappliedtotheUnitIterminationmoduleswasdefectiveinonemajorarea.Thein-processinspectionsystemdidnotincludethephysicalinspectionofthepininsertionprocess.(Theassumptionthatcontinuityandinsulationtestingwoulddetectallfunctionallysignificantinsulationdamagehasnotbeenconfirmed).Addedin-processinspectionpointsandareviseddetailed.inspection.-planhavebeenaddedtotheassemblyoperationoftheT-Mods.
ATTACE4EIQ'Page30I62.HandlingandStorageOperatortraininginthehandlingofT-Modswithproperphysicalseparationand,stackingwillreduceobservedproblemsinthisarea.Inaddition,theT-Mods,whencomplete,willbestyrofoamwrappedandtapedtoprecludestorageandshippingdamage.(Thispracticewasimplementedinearly1977.)3~ProducibilityOntheUnitIreworkoftheT-Nods,severalproducibilitychangeswhichhavebeenimplementedonsubsequentprojectswillbeapplied:a.Tensolitewirewhichislesssusceptible,toabrasionand'dinging'illbeappliedtoreworkedT-Mods.b.AnalternatemethodofshieldingwhichdoesnotrequiretheferruleconceptwillbeappliedtoreworkedT-mods.c.LongerfreeconductorlengthforeaseofassemblywillbeappliedtoreworkedT-Nods.ConclusionTherepair/reworkandre-testoftheT-NODSforSSESUnit1hasbeenaccomplishedperGEproceduresandcriteria.Thedeficiencyhasnowbeencorrectedandthepotentialsafetyhazardhasbeeneliminated.TheSSESUnit1reworkedT-Nodsh'avebeenshippedandinstalledatthejobsite.AportionoftheUnit2T-NodsweremanufacturedinthesametimeperiodastheUnit1T-Mods.InspectionwillbeperformedatSSESperaGEdocumentFDIMDBC.DefectiveunitswillbereturnedtoGEforrepairbeforefuelload.GEfabricationpersonneltraining,.inspectionandrevisedfabricationtechniqueshasprecludedreoccurrenceofsimilarproblemsontheremainingUnit2T-Nods.TheinspectionstobeconductedinaccordancewithFDIMDBCincludea100$visualinspectionofterminalstripsforcracked.,brokenormissingbarriersandconductorinsulationfornicks,abrasionandcuts.Theexistenceofanyoftheseconditionsiscauseforrefection.SK:po2873 QAYAREDO50455OASISbAXPdtGAY0L%th'3.08420ATTACKZNTPage4of6l,r)~taTKNWOVLKGAYCtarviaDAf5nERBAYDtIihR~i'>~lJOARRCRCONIECTOR~TE$TATlONARYQAttltlERSFUXRFlATKt4PPCltTFCSTAgee04,AssembledTarnationCo%~(Doomremovodlotch~-~~reels~iai~p~'pie~eI~~O~iii'".S~~a'~iver~.a:'Sr
'sA"208420ATTACHMEHTPage5ofI~~~~y~y~~CCNNECTO'asmuoM~~817 HED0.10468'TTACHi~ITPage6of6v~~vIrv'(IPrvfILLSCASLC0000~~o~i'000~~~~~~1~~~o'~~~~~~~~~~V~~~~~~~~~~0lPt>.~~~I~~~~~~~4VNCTlOMSOX
'I