ML18023A884

Susquehanna Units 1 and 2 - Letter Regarding an Interim Report of Reportable Deficiency

ML18023A884
Person / Time
Site:	Susquehanna
Issue date:	07/25/1975
From:	Curtis N W Pennsylvania Power & Light Co
To:	O'Reilly J P NRC Region 1
References
IR 1975005, IR 1975006
Download: ML18023A884 (7)

Text

PENNSYLVANIAPOWER&LIGHTCOMPANYDATEOSDOCUMENT7/25/75LTR,MEMO,DATERECEIVED7/28/75REPORTNO50597OTHERTOCCORIG.IXI'E(THORNBURG)CLASSIFPOSTOFFICEREG.NO'CTIONNECESSARYQNOACTIONNECESSARYQFILECODE'.CONCURRENCECOMMENT0DATEANSWERED,0eYIDEscRIpTIDNIMusseeUsscsessisedl50"387-388SUSQUEHANNASTEAMELECTRICSTATIONSINTERIMREPORTOFREPORTABLEDEFICIENCYBOXCOLUMNSUPPORTS+REFERREDTOERTERECEIVED8YDATEIENCLOSURES.COPIESFORPDRLOCALPDRqNSICFANDDTXE"SENTTOREGIONALCOORDINATORFORDISRIBUTIONoa~J/PSREMARKSCOPYSENTTOREGIONICOPYSENTTORoAoHARTFIELDU,SNUCLEARREGULATORYCOMMISSIONFORMtlRCZXSMAILCONTROLFORMI'ITS)

~yPP8LTWONORTHNINTHSTREET,ALLENTOWN,PA.18101PHONE<(215)821.5151July25,1975Mr.J.P.O'ReillyDirector-RegionIU.S.NuclearRegulatoryCommission931ParkAvenueKingofPrussia,Pennsylvania19406SUSQUEHANNASTEAMELECTRICSTATIONINTERIMREPORTOFREPORTABLEDEFICIENCYBOXCOLUMNSUPPORTSDOCKETNOS.:50-387and50-388LICENSENOS.:CPPR-101andCPPR-102ERs100450/100508FILE840<<4PLA-74

DearMr.O'Reilly:

Thisrelatestoan"unusualoccurrence"whichwasreportedtotheassigned.s'egulatoryInspector,Mr.J.Mattia,inthecourseofhisunannouncedinspectionvisitofMay19-23,1975(

Reference:

IE:IReportsNo.387/75-06and388/75-05).Theinspectorwasinformedthatlinearindicationshadbeendiscoveredduringavisualinspectionoftheweldpointsoftwoboxcolumnsupportbases.ItwasalsostatedthatthesignificanceoftheseindicationswasbeingevaluatedtodeterminetheirreportabilityundertheprovisionsdescribedinTitle10,CodeofFederalRegulations,Part50,Section50.55(e).ThisevaluationhasbeencompletedbyPPSLanditsContractor(Bechtel)andithasbeenconcludedthatthestructural-components,whichhavebeenestablishedasbeingdefective,representadeficiencyinconstruction(fabrication)whichwillrequireextensiverepairorredesignandreplace-ment;andwhich,werethedeficienciestohaveremaineduncorrected,could.haveanadverseeffectonthestructureintheperformanceofitsintended.safetyfunction(Ref.50.55,(e),(iii)).PPEcLexpectstosubmitadefinitivereportofthedeficiencyand.safetyimplicationsandtheelectedcourseofcorrectiveactionwithinthe30-dayperiodprescribedbythereferencedregulation.Shouldit,atanytime,bediscoveredthatthisschedulecannotbemet,youwillbepromptlyin-formed.PENNSYLVANIAPOWER8LIGHTCOMPANYOgg'PgL TWONORTHNINTHSTREET,ALLENTOWN,PA.18101PHONEs(215)8215151Mr.J.P.PLA.-74Pae2O'ReillyThefollowingisanaccountofrelevantdetailswhichled.tothediscoveryofthedeficiency,theinvestigationspursued.and.thedatawhichhasbeenestablished,todate:Inthecourseofconductingrandom,impromptumonitoringofinstalledstructuresofSSESUnit1,PP&L,NuclearQualityAssurancenoted,visually,theappearanceofweldsonfour(4)boxcolumnbasesandquestioned,theircompliancewithAWSDl.l.PP&LDeficiencyReportNo.0022wasissuedtodocu-mentthecondition.20Subsequently,closerscrutinyrevealedtheexistenceofavisiblediscontinuityatthetoeofafullpenetrationweldJoiningastiffenermemberotheverticalboxsectionofBoxColumnSupportS-27.5.Theconditionwasnoted.andidentified.onBechtelNCR376asbeingsuspectandrequiringfurtherexaminationbynondestructiveexamination(NDE).Sinceultrasonicshadbeenrequiredinthepurchasedocuments,thistechniquewasrequiredtobeemployedagain.3~Further,thisdiscoveryinstigatedadditionalvisualexamina-tionsoftheremainingseven(7)similaritems.TheadditionalvisualexaminationsrevealedasimilarsuspectconditiononsupportQ-36.NCR377documentedthecondition.Furtherexaminationswerepursuedutilizingultrasonics.4.TheinvestigationofthereferencedsupportswasperformedbyBechtel'sNDEsubcontractor.Ultrasonicsrevealedthat,forsupportS-27.5,adefectwaspresentandvariedindepthfromsurfaceto1-3/8"depthandwasapproximately37"long.ForsupportQ-36,thedefectdepthvariedfromsurfaceto1-3./4"depthandwasapproximately27"long.5~Basedonthesepreliminaryresults,thesteelfabricator,BethlehemSteelCompany,Pottstown'Plant,wasnotifiedand.enlisted.toperformUTreexaminationofalleight(8)oftheBoxColumnSupportswhichhad.beeninsta11edintheirrespectivelocationsforUnits1and2.Thesupplier'sreexaminationproducedevidenceofoneadditionaldefectinthevicinityofthetoeoftheweldJoiningastiffenertotheboxsectionofsupportQ-22.ForsupportQ-22,thedefectvaried.indepthfrom1/2"to1-3/4"by37"longand.terminatedbehindtheweld.intothebasematerialoftheboxsection.NCR401wasissuedtodocumentthecondition.PENNSYLVANIAPOWERELLIGHTCOMPANY

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~.>><<OeTWONORTHNINTHSTREET,ALLENTOWN,PA.18101PHONEME(215)8215151Mr.J.P.O'ReillyPLA-V4Pae36.DuringUTexaminationoftheeight(8)supports,itwasdeterminedthatadditionalindications(interpretedsubse-quentlyaslamellartearing)existedinthebasematerialintheverticalplatemembersofboxsectionsinfour(4)locations.NCR402wasissuedtodocumenttheexistenceoftheindicationsfoundonBoxColumnSupportsQ-22,Q-36,S-30.5andS-36.7.Bechtelhasinvestigated.thedesignbasesandthroughitsinvestigationconcludesthatthecolumns,evenwiththeidentifieddeficiencies,wouldhavesustainedtheloadsforwhichtheywereoriginallydesigned.However,onthebasisofconservatismandthelackofabsoluteassurancethatthedefectswould.notpropagatefurther,wehavedecidedtoreplacethecolumnbases.Regardingthenatureofthedefects,lamellartearingwhichissuspected.,isaphenomenonwhichhasreceived.attentionintheindustryfairlyrecentlyandtherefore,severalaspectsofthisphenomenonarenotyetfullydefined.andunderstood.EvaluationbymetallurgistsfromBechtel'sMFLQCSDepartmentand.fromBethlehemSteelCorporationindicatethatmostprobablythelamellartearswillnotpropagateanyfurthersincethestress(probablyduetoweldshrinkage)isrelievedduetolamellartearingandsince,duringtheservicecondition,adirecttensileloadwillnotbeappliedtotheaffectedarea.However,itisnotpossibletoprovideanabsoluteassurancethatthelamellartearswillnotpropagateatallduringthelifeoftheplant.Underthecircumstances,wehavetoconcludethatifthedeficiencyhadremaineduncorrected,andifitisassumedthatthelamellartearingwouldhavepropagatedexten-sively,thenthisdeficiencymayadverselyaffectthestructuralintegrityoftheplant.Therefore,wehaveconsideredthisdeficiencytobe"reportable"inaccordancewithparagraph(e)of10CFR50.55.Sincediscoveryofthereporteddeficiencies,allitemshavebeenproperlyidentifiedandtagged.toprecludecontinuationofanyworkwhichwouldhavemadethesupportsinaccessibleforfurtherexamination.DiscussionsareunderwaybetweenPPEcLand,BechteltodispositiontheNonconformanceReportsreferenced.Thesedispositionswillprovidethebasisforcorrectiveactionandwillbeindicatedintheformalreporttothe.CommissioninsatisfactionofthestipulatedrequirementsofPart50.55(e).PENNSYLVANIAPOWER8aLIGHTCOMPANY

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~0a0~TWONORTHNINTHSTREET,ALLENTOWN,PA.18101PHONE>(215)8215151Mr.J.P.O'Reillypm-V4Pse4Becauseoftheindeterminatenatureofthelamellartearingphenomenonandtheinherentrisksinattemptingrepairs,weexpecttoreplaceall8columnsupportbaseswith8newsupportseventhoughtheNDEinspectionhasestablishedthat3ofthe8originalsupportshad.nodiscernabledefects.Wetrustthisinformationadequatelyaddressestheinterimreportingrequirementsof10CFR50.55(e)and,awaityouracknowledgementoradviceofadditionalrequirements.Verytrulyyours,N.W,CurtisVicePresident-EngineeringandConstruction'worntosndsubscribedbeforemethis~R~of~1975.'NotaryPublicMy'commissionexpires:ARS:bcc:Mr.DonaldF.KnuthDirectorOfficeofInspectionandEnforcementU.S.NuclearRegulatoryCommissionWashington,D.C.20555PENNSYLVANIAPOWER5LIGHTCOMPANY