ML16172A019

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STP Aluminum Bronze Selective Leaching Public Meeting - June 21, 2016
ML16172A019
Person / Time
Site: South Texas  STP Nuclear Operating Company icon.png
Issue date: 07/25/2016
From:
Division of License Renewal
To:
james l m
References
CAC ME4936, CAC ME4937
Download: ML16172A019 (18)


Text

STPAluminumBronzePublicMeetingStaffQuestionsonAMPJune21,201618 Introduction*Thispresentationsummarizescomments/questionsonAMPB2.1.37,"SelectiveLeachingofAluminumBronze."*Comments/questionsareorganizedinaccordancewiththeStandardReviewPlanforLicenseRenewal,AppendixA.1.2.3,"AgingManagementProgramElements."18 ScopeofProgramProgramstatesthatextrudedteeswithweldrepairswillbereplacedifitisdeterminedthat"therepairsizeissuchthatfailureoftherepairwouldaffectstructuralintegrityofthecomponent."*Duringtheaudit,theapplicantstatedthatweldrepairsizewasnotknownforalloftheaffectedtees.*Staffneedstounderstandhowthestructuraldeterminationwillbemadeintheabsenceofthisdetail.18 PreventiveActions*Documentwhichportionsoftheburiedessentialcoolingwatersystemarecoated.*Citethecoatingasapreventiveaction-orcitesoilasanapplicableenvironment.*Thestatementsonaluminumbronzecastingsandextrudedpipingteesneednotberepeatedinthisprogramelement.18 ParametersMonitoredorInspected*TheAMPshouldconsistentlycitethefollowingparameters:-Lossofmaterial(agingeffect)[sometimesreferredtoasselectiveleachinginAMP]-Cracking(agingeffect)-Phasedistribution(indirectmeasureofthepotentialforcontinuousdealloying)*4thparagraphstatesthatOEhasshownthatcertainweldsare"notsusceptibletocrackingcausedbyselectiveleaching."-OEonlydemonstratesthattherearenothroughwallindications18 DetectionofAgingEffectsBuriedpipeinspectionswhenpipeisexposed:*Whatisthemethodofinspection?*Istheinspectionconductedoninternal,external,orbothsurfaces?18 DetectionofAgingEffectscont.WeldwithNoBackingRings*Staffbelievesthatvolumetricinspectionsshoulddemonstratenocrackingaccompaniedbydealloying.*Volumetricinspections,onetimeinspectionof3%oftheweldswithamaximumof10welds.-AMPXI.M32,"OneTimeInspection,"recommends20%withamaximumof25.PriortoPEO.-QuantityisinconsistentwithGALLReportrecommendations.*Programstatesthat,"[i]frejectableweldflaws,"aredetected,inspectionswillbecomeperiodicinlieuofonetime.-Howmanyweldflawswillittaketotransitiontoperiodicinlieuofonetimeinspections?18 DetectionofAgingEffectscont.WeldwithBackingRings*Staffbelievesthatvolumetricinspectionsshoulddemonstratenocrackingaccompaniedbydealloying.*Periodicinspectionof20%oftheweldswithamaximumof25welds*Programstates,"ifnowelddefectsarefound"thenumberofinspectionswillbereducedto3%withamaximumof10welds.-Howmanyweldflawswillittaketonottransitiontothereducednumberofinspections?18 DetectionofAgingEffectscont.DestructiveExaminations*Staffbelievesthatexaminationsaretodemonstrate:-forweldswithoutbackingrings,nolossofmaterialduetouniformorpluglikedealloying,aphasedistributionthatsupportsthebasisdocument,andnocrackingaccompaniedwithdealloying-forweldswithbackingrings,nolossofmaterialduetouniformorpluglikedealloying,aphasedistributionthatsupportsthebasisdocument,andthefrequencyofoccurrenceofcrackingaccompaniedwithdealloying*Theprogramstatesthattwoweldswithbackingringswillbedestructivelyexamined.-AMPXI.M32recommends20%withamaximumof25.*Staffbelievesthatweldswithbackingringsandweldswithoutbackingringsaretwoseparatepopulations-Backingrings-creviceforselectiveleaching-Withoutbackingrings-lessdilutionandlongercoolingperiodinrootweld18 DetectionofAgingEffectscont.InspectionLocationsProgramstatesthatinspectionlocationswillberandomlyselected.*Staffbelievesthatinspectionlocationscanberandom.*Locationsshouldberepresentativeofrangeandquantityofweldsizes.InspectionTimingProgramisnotclearonwhetheronetimeinspectionsoccurpriortoPEO.*Periodicinspectionof20%oftheweldswithamaximumof25weldsif"rejectableweldflaws-."aredetected.-"Performedevery10yearsthereafter."18 MonitoringandTrending*Thestaffrecognizesthatquantitativeresultswillnotbeobtainedbytheplannedvolumetricanddestructiveinspections/examinations.*Withouttrending,inspectionresultswouldbe"buried"inthecorrectiveactionprogram.*Thestaffneedstounderstandwhytheresultsofthevolumetricanddestructiveinspectionswillnotbecompiled(trended)andthecompiledresultsevaluated.*Thestaffneedstounderstandwhytheresultsofthewalkdownswillnotbetrended.18 AcceptanceCriteriaTheAMPstatesthattheacceptancecriteriaforweldsisnodefects:*A/Cforvolumetricexaminationsis,nodefects.*Parametersmonitoredorinspectedprogramelementstates,"Ifrejectableweldflaws(welddefects)perASMESectionIX-."-Programisunclearinthatitaddressesflawsanddefects.-WhyisSectionIXcited?-CitingSectionIIIcouldleadtononconsequential(fordealloying)defects(e.g.,concavitywithweldsizeslightlyunderthickness(suckback),roundedindications>5/32",inadequatepenetration).-CitingSectionIIIcouldleadtoanalyticalresolutionthatadefectisclassifiedasaflaw.*Describethespecificcriteriafordeclaringthatanindicationinaweldisrejectable.18 AcceptanceCriteriacont.*Thereisnoacceptancecriteriaforthedestructiveexaminations.*Whyistherenoacceptancecriteriaforthedetectionofpluglikeoruniformdealloying?*Whyistherenoacceptancecriteriaforburiedpipecoatings?18 CorrectiveActionsExpansionofExaminations*AMPstatesthateachweldfoundtohavedefectswillresultinfiveadditionalvolumetricexaminationsuntilnoadditionalwelddefectsaredetected.*Willexpansionofinspectionsbeconductedifabovegroundleaksaredetected?-Leaksshouldnotbedetectedoncecastingsarereplaced,regardlessoftheuseofbackingrings.-Whattypeofexpandedinspectionwillbeconductedifleaksaredetected(e.g.,volumetric,destructive).*Whatcorrectiveactionswilloccurifdealloyingisdetectedinweldswithoutbackingrings?*Forweldswithbackingrings,whatcorrectiveactionswilloccurdependingonthefrequencyofoccurrenceofcrackingaccompaniedwithdealloying?18 CorrectiveActionscont.ExpansionofExaminations*AMPstatesthatifburiedpipeleakisdetected,"asectionofeachleakingpipeweldwillberemovedfordestructiveexamination."-Willanexpansionofinspectionsbeconducted?*Willexpansionofdestructiveexaminationsbeconductedifacceptancecriteriafordestructiveexaminationsisnotmet?*Correctiveactionsforthedetectionofpluglikeoruniformdealloying?*Correctiveactionsforburiedpipecoatingdefects?18 BasisDocument*Enclosure1,page54,Table12-Whyisthe30inch,dischargesidetee(withamarginof1.01ofallowablelengthtoleaklength)acceptableforserviceinthePEO?*Enclosure1,page53,Table11-Walkthroughhowthistablewasdeveloped.-Whywastheunintensifiedbendingstressused?*Enclosure1,Table1-ReviewinstancesofOEwhereindicationswere:*"nearandparalleltothebuttweld"page21*"alongalineontheflangenecknearthebuttweld"page22*"nearthebuttweld"page2318 EditorialComments*Theperiodicwalkdownofabovegroundweldlocationsshouldbecitedinthe"parametersmonitoredorinspected"programelement.*Theperiodicwalkdownofyardareastodetectburiedpipeleaksshouldbecitedinthe"parametersmonitoredorinspected"programelement.*Programstatesthattheenvironmentisrawwater;however,soilshouldalsobecited,unlesscoatingscredited.*Firstenhancementstatesthataluminumbronzecastingswillbereplaced;however,itisdoesnotstatethatthereplacementmaterialwillnotbesusceptibletoselectiveleaching.*Correctiveactionsprogramstates,"leakfromaburiedpipeweld."Itshouldbemadeclearthattheweldcouldbe:(a)tononsusceptiblepipe,(b)tosusceptiblecastcomponents,or(c)therepairweldinanextrudedtee.ThisshouldbemadeclearthroughouttheAMP.18 Summary/Wrapup18