Information Notice 2001-06, Centrifugal Charging Pump Thrust Bearing Damage Not Detected Due to Inadequate Assessment of Oil Analysis Results and Selection of Pump Surveillance Points: Difference between revisions
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{{#Wiki_filter:UNITEDSTATESNUCLEARREGULATORYCOMMISSIONOFFICEOFNUCLEARREACTORREGULATIONWASHINGTON,D.C.20555-0001May11,2001NRCINFORMATIONNOTICE2001-06:CENTRIFUGALCHARGINGPUMPTHRUSTBEARINGDAMAGENOTDETECTEDDUETO INADEQUATEASSESSMENTOFOILANALYSIS RESULTSANDSELECTIONOFPUMP SURVEILLANCEPOINTS | {{#Wiki_filter:UNITEDSTATESNUCLEARREGULATORYCOMMISSIONOFFICEOFNUCLEARREACTORREGULATIONWASHINGTON,D.C.20555-0001May11,2001NRCINFORMATIONNOTICE2001-06:CENTRIFUGALCHARGINGPUMPTHRUSTBEARINGDAMAGENOTDETECTEDDUETO | ||
===INADEQUATEASSESSMENTOFOILANALYSIS=== | |||
RESULTSANDSELECTIONOFPUMP | |||
===SURVEILLANCEPOINTS=== | |||
==Addressees== | ==Addressees== | ||
Allholdersofoperatinglicensesfornuclearpowerreactors,exceptthosewhohavepermanentlyceasedoperationsandhavecertifiedthatfuelhasbeenpermanentlyremoved fromthereactor. | Allholdersofoperatinglicensesfornuclearpowerreactors,exceptthosewhohavepermanentlyceasedoperationsandhavecertifiedthatfuelhasbeenpermanentlyremoved | ||
fromthereactor. | |||
==Purpose== | ==Purpose== | ||
TheU.S.NuclearRegulatoryCommission(NRC)isissuingthisinformationnoticetoalertaddresseesthatinadequateassessmentofpumpoilanalysisresults,combinedwith surveillancetestingwhichdoesnotmonitorallrelevantpumpoperatingconditions,mayallow severepumpdegradationtogoundetected.Itisexpectedthatrecipientswillreviewthe informationforapplicabilitytotheirfacilitiesandconsideractions,asappropriate,toavoid problems.However,thesuggestionscontainedinthisinformationnoticearenotNRC requirements;therefore,nospecificactionorwrittenresponseisrequired.DescriptionofCircumstancesOnJune19,2000,whiledisassemblingtheCcharging/safetyinjectionpump(CSIP)toreplaceamechanicalseal,ShearonHarrisNuclearPlant(SHNP)personneldiscoveredsignificant damagetotheoutboardthrustbearing.Furtherexaminationrevealedthatthebabbittmaterial onthebearingshoesofthismulti-padthrustbearinghadmeltedandre-solidifiedwithinthe thrustbearingcagearea.Onboththeshoesandthesleeveofthethrustbearing,radialwearin thedirectionofnormalpumprotationwasindicativeofmetal-to-metalcontactbetweenthetwo surfaces.Theinboardradialbearingandshaftalsohadminorwear.SHNPstatedina licenseeeventreport(Reference1)thatthemostprobablecauseofthedamagewasa momentarylossoflubricationflowtotheoutboardthrustbearing.Aninadequatefill-and-ventof thepump,whichmayhavecausedamomentaryincreaseintheaxialthrustontheoutboard thrustbearing,wasalsogivenasapotentialrootcause.ElementalanalysisofaroutinepumpbearingoilsampletakenonSeptember19,1999,usingadirectcurrentplasma(DCP)spectrometer,revealeda40-foldincreaseintheparticlecountin therangeof5to10micronsovertheprevioussampletakenonMay11,1999.(Theparticle countincreasedfrom15,800to660,000countsper100millilitersample.)AllothertestedML011070643 IN2001-06Page2of5parameterswerenormal.SHNPreviewedtheElectricPowerResearchInstitute(EPRI)LubricationGuide(Reference2)andconcludedthatthesizerangeofthesewearparticleswas consistentwithbenignwear.ThebearingoilintheCSIPwasreplacedonDecember21,1999, andSHNPcontinuedsamplingat6-monthintervals.Thenextoilsample,takenon February23,2000,alsoshowedahighparticlecountinthe5to10micronrange.Trace amountsofironandtinwerealsodetectedforthefirsttime.Theanalysisofanotheroilsample takenonJune18,2000,foundthatthelevelsofallparametersweresimilartothelevelsinthe February23,2000,sample.EachCSIPatSHNPisaPacificModel21/2RLIJ,11-stage,centrifugalpumpmanufacturedbyFlowserveCorporation,formerlyIngersoll-DresserPumpCompany.TheCCSIPisthestandby pump.Duringtheperiodinwhichhighparticlecountsinthethreeoilsamplesweredetected, theCpumpwasintermittentlyinservicetosupportplantoperations.Surveillancetesting,as requiredbytheSHNPinservicetestingprogramandtheSHNPTechnicalSpecifications,was performedontheCpumpduringthisperiod.Inservicetests,includingvibrationmeasurement, wereconductedduringplantoperationonNovember13,1999,andJanuary3,2000,withthe pumpoperatingatthenormalchargingflowrateofapproximately90gallonsperminute(gpm). | TheU.S.NuclearRegulatoryCommission(NRC)isissuingthisinformationnoticetoalertaddresseesthatinadequateassessmentofpumpoilanalysisresults,combinedwith | ||
surveillancetestingwhichdoesnotmonitorallrelevantpumpoperatingconditions,mayallow | |||
severepumpdegradationtogoundetected.Itisexpectedthatrecipientswillreviewthe | |||
informationforapplicabilitytotheirfacilitiesandconsideractions,asappropriate,toavoid | |||
problems.However,thesuggestionscontainedinthisinformationnoticearenotNRC | |||
requirements;therefore,nospecificactionorwrittenresponseisrequired.DescriptionofCircumstancesOnJune19,2000,whiledisassemblingtheCcharging/safetyinjectionpump(CSIP)toreplaceamechanicalseal,ShearonHarrisNuclearPlant(SHNP)personneldiscoveredsignificant | |||
damagetotheoutboardthrustbearing.Furtherexaminationrevealedthatthebabbittmaterial | |||
onthebearingshoesofthismulti-padthrustbearinghadmeltedandre-solidifiedwithinthe | |||
thrustbearingcagearea.Onboththeshoesandthesleeveofthethrustbearing,radialwearin | |||
thedirectionofnormalpumprotationwasindicativeofmetal-to-metalcontactbetweenthetwo | |||
surfaces.Theinboardradialbearingandshaftalsohadminorwear.SHNPstatedina | |||
licenseeeventreport(Reference1)thatthemostprobablecauseofthedamagewasa | |||
momentarylossoflubricationflowtotheoutboardthrustbearing.Aninadequatefill-and-ventof | |||
thepump,whichmayhavecausedamomentaryincreaseintheaxialthrustontheoutboard | |||
thrustbearing,wasalsogivenasapotentialrootcause.ElementalanalysisofaroutinepumpbearingoilsampletakenonSeptember19,1999,usingadirectcurrentplasma(DCP)spectrometer,revealeda40-foldincreaseintheparticlecountin | |||
therangeof5to10micronsovertheprevioussampletakenonMay11,1999.(Theparticle | |||
countincreasedfrom15,800to660,000countsper100millilitersample.)AllothertestedML011070643 IN2001-06Page2of5parameterswerenormal.SHNPreviewedtheElectricPowerResearchInstitute(EPRI)LubricationGuide(Reference2)andconcludedthatthesizerangeofthesewearparticleswas | |||
consistentwithbenignwear.ThebearingoilintheCSIPwasreplacedonDecember21,1999, andSHNPcontinuedsamplingat6-monthintervals.Thenextoilsample,takenon | |||
February23,2000,alsoshowedahighparticlecountinthe5to10micronrange.Trace | |||
amountsofironandtinwerealsodetectedforthefirsttime.Theanalysisofanotheroilsample | |||
takenonJune18,2000,foundthatthelevelsofallparametersweresimilartothelevelsinthe | |||
February23,2000,sample.EachCSIPatSHNPisaPacificModel21/2RLIJ,11-stage,centrifugalpumpmanufacturedbyFlowserveCorporation,formerlyIngersoll-DresserPumpCompany.TheCCSIPisthestandby | |||
pump.Duringtheperiodinwhichhighparticlecountsinthethreeoilsamplesweredetected, theCpumpwasintermittentlyinservicetosupportplantoperations.Surveillancetesting,as | |||
requiredbytheSHNPinservicetestingprogramandtheSHNPTechnicalSpecifications,was | |||
performedontheCpumpduringthisperiod.Inservicetests,includingvibrationmeasurement, wereconductedduringplantoperationonNovember13,1999,andJanuary3,2000,withthe | |||
pumpoperatingatthenormalchargingflowrateofapproximately90gallonsperminute(gpm). | |||
PerformancedatafrombothtestsindicatedtheCCSIPmettheestablishedpumphydraulic | |||
andmechanicalacceptancecriteriaintheAmericanSocietyofMechanicalEngineers(ASME) | |||
CodeforOperationandMaintenanceofNuclearPowerPlants(OMCode),andnoadverse | |||
trendswerenoted.OnApril23,2000,arefuelingoutagetesttosatisfytheSHNPtechnical | |||
specificationswasperformedsuccessfully,withthepumpachievingaflowrateof609gpm.Subsequenttothediscoveryoftheseverelydegradedoutboardpumpthrustbearing,discussionswiththepumpmanufacturerrevealedthatatflowratesbetweenapproximately250 | |||
and600gpm,thenetaxialthrustofeachSHNPCSIPpumpisinthedirectionoftheoutboard | |||
thrustbearing.Therefore,SHNPconcludedthatduringnormalplantoperationandsurveillance | |||
testing,theoutboardthrustbearinghadbeeneithernotloadedoronlylightlyloaded.In | |||
addition,SHNPcouldnotassessthecapabilityoftheCCSIPtoperformitsfunctionduringa | |||
small-break,loss-of-coolantaccident,inwhichthepumpaxialthrustwouldhavefullyloadedthe | |||
outboardthrustbearing.InresponsetoanNRCnoticeofviolation(Reference3),SHNPdescribedcorrectivestepseithercompletedorinprogresstoaddressthisissue.Theseincluded(1)counselingoperators | |||
onconsequencesofimproperpumpfill-and-ventoftheCSIP,(2)establishingoilanalysis | |||
criteriaforincreasedlubricantparticlecounts,(3)reinforcingexpectationsfordispositionof | |||
abnormalindications,(4)samplingCSIPlubricatingoilquarterlyinsteadofsemi-annually, | |||
(5)revisingthemaintenanceproceduretoensurethattheCSIPlubricatingoilsystemwill | |||
functionasexpected,and(6)implementingadesignmodificationtoinstalltemperatureand | |||
vibrationproximityprobesoneachCSIP. | |||
IN2001-06Page3of5NRCRequirementsandIndustryGuidanceandPracticesonPumpConditionMonitoringThecurrentrequirementsforinservicetestingofsafety-relatedpumpsarespecifiedinSection50.55aofTitle10oftheCodeofFederalRegulations(10CFR50.55a),"Codesand | |||
Standards."Forplantswhicharerequiredtoupdatetheirinservicetesting(IST)programsafter | |||
September22,2000,whichisoneyearaftertherecentchangeto10CFR50.55a(Reference | |||
4),Subsection(b)(3)requiresthatsafety-relatedpumpsbetestedtothe1995Editionandthe | |||
1996AddendaoftheASMEOMCode.TheCoderequiresthatsafety-relatedpumpsbetested | |||
bienniallyat+/-20%oftheirdesignflowrate,andeverythreemonthsatspecificreferencepoints. | |||
OverallvibrationmeasurementsofeachpumpbearingaretakenasspecifiedbytheCode.The | |||
SHNPISTprogramisinaccordancewithanearlierversionoftheCode,whichrequirespump | |||
testingtobeconductedeverythreemonthsatreferencepointsofoperationreadilyduplicated | |||
duringsubsequenttests.Pumphydraulicperformanceisassessedbycomparingcurrent | |||
performancewithreferencevaluesestablishedwhenthepumpisknowntobeoperating | |||
acceptably.Pumpmechanicalperformanceisassessedlikehydraulicperformance,unlessthe | |||
specifiedmultipleofthemeasuredoverallvibrationreferencevalueexceedstheabsolute | |||
vibrationacceptancecriterion.NeithertheCodenortheregulationsrequireanyspecificpumpconditionmonitoringactivitiestobeperformedonsafety-relatedpumps.However,theNRChasobservedduringinspection | |||
activitiesthatmanyUScommercialnuclearpowerplantshavesometypeofcondition | |||
monitoringprogramfortheirrotatingmachinery.Theseprogramsusuallyincludebothsafety- relatedandnon-safety-relatedequipment.Becausenoregulationscovertheseprograms,the | |||
testingperformed,theexaminationscompleted,andtheacceptancecriteriausedforeach | |||
conditionmonitoringactivityvarywidely.TheEPRILubricationGuideincludesinformationonthetestingandanalysisoflubricants.Theguideidentifiesparticlesizeandwear-metalcontentaskeypropertiestoanalyze.Theguide | |||
alsoprovides"classic"warninglimitsforcertainmeasuredproperties.Theguidedoesnot | |||
recommendaspecificwarninglimitforparticlecount.However,theguideemphasizestrending | |||
criticalpropertiesofaspecificapplicationandestablishingappropriatewarninglimits.When | |||
theselimitsareexceededandtheresultsareverified,theguiderecommendsoilreplacement | |||
andfurtherstudyifnecessary.TheNRChasauthorizedalternativestotheCodevibrationrequirementsbasedontheperformanceofpumpconditionmonitoringactivities.Forexample,aspartofanalternativeto | |||
theCodevibrationacceptancecriterion,onefacilitycommittedtoimplementaplant-specific | |||
pumpconditionmonitoringprogramforcertainsafety-relatedpumps.TheNRChasdetermined | |||
thatthisproposedalternativedemonstratesanacceptablelevelofqualityandsafety. | |||
IN2001-06Page4of5DiscussionAkeyfactorinthefailuretodiscoverthedamagedbearingbeforedisassemblywasnotactivelypursuingtherootcauseoftheabnormallyhighparticlecountintheSeptember19,1999,oil | |||
sample.TheEPRIguideimpliesthatparticleslessthan10micronsinsizearegeneratedfrom | |||
"benignwear."Theguidedoesnotdiscussthesignificanceofchangesinwearparticle | |||
concentration.However,theguidedoesdiscusstrendingofparameters.SHNPperformed | |||
spectroscopicanalysisofeachsampleandtrendedtheresultsofthesetests.Thelowweight | |||
percentofthewearparticleswasapparentlythereasonwhytheelementalanalysisdidnot | |||
detectthepresenceofbearingmaterial.Ferrographyandelectronmicroscopicscan | |||
examinationwereconductedafterthediscoveryofthebearingdegradationandthereforewere | |||
notafactorindiagnosingtheelevatedparticlecount.SHNPelectedtocontinuewitharoutine | |||
oilsamplingscheduledespitethehighparticlecountandthelackofaplausiblerootcausefor | |||
thiscondition.Amoreaggressiveoilsamplingschedule(e.g.,weekly)wouldlikelyhave | |||
revealedtheseverelydegradedoutboardthrustbearingseveralmonthsbeforethepumpwas | |||
disassembled.Inserviceandtechnicalspecificationsurveillancetestingdidnotindicatethattheoutboardthrustbearingwasseverelydamaged.Thepurposeofpumpinservicetestingistoidentify | |||
degradationbeforethepump'sperformanceofitssafety-relatedfunctionisimpaired.Forthe | |||
chargingpumpsattheSHNP,thepurposeoftechnicalspecificationtestingistoverifythatthe | |||
pumpwilldeliveraspecificflowattherequiredtotaldevelopedhead.Thefailureofbothtests | |||
toindicatebearingdegradationappearstohavebiasedthedecisiontonotinvestigatethe | |||
elevatedparticlecount.Informationprovidedbythevendorrevealedareversalinthedirectionofthepumpaxialforceasafunctionofthepumpflowrate.ThispumpdesigncharacteristicwasunknowntoSHNP | |||
personnelbeforetheydiscoveredtheseverelydegradedbearingandthentalkedwiththe | |||
vendor.TheCodedoesnotrequireSHNPtoaccountforthisdesignconditionthroughtesting. | |||
Thetechnicalspecificationfullflowtestafterthefirstdetectionofthehighparticlecountneither | |||
detectedthisconditionnorcausedacatastrophicfailureofthepump.Thisissueillustratesthat | |||
theassessmentofsafety-relatedpumpperformanceisdependentnotonlyonverifying | |||
successfulsurveillancetesting,butalsoonunderstanding(1)pumpandsystemdesignand | |||
performancecharacteristics,(2)performancetestingresults,and(3)theresultsofcondition | |||
monitoringactivitiesandtheircorrelationwithknownpumpdesigncharacteristicsand | |||
performancetestresults. | |||
IN2001-06Page5of5GenericImplicationsIftrendsofconditionmonitoringdataarenotactivelyinvestigatedwhentheydeviatefromanestablishedbaseline,alicenseemayoverlooksignificantpumpdegradationthatisnotdetected | |||
byperformancetesting.Thisinformationnoticerequiresnospecificactionorwrittenresponse.Ifyouhaveanyquestionsaboutthisnotice,pleasecontactoneofthetechnicalcontactslistedbeloworthe | |||
appropriateOfficeofNuclearReactorRegulation(NRR)projectmanager./RA/LedyardB.Marsh,Chief | |||
EventsAssessment,GenericCommunicationsandNon-PowerReactorsBranchDivisionofRegulatoryImprovementPrograms | |||
OfficeofNuclearReactorRegulationTechnicalcontacts:J.Colaccino,NRRBobHagar,RegionII301-415-2753919-362-0601 E-mail:jxc1@nrc.govE-mail:rch2@nrc.gov:Attachments:1.ListofReferences | |||
2.ListofRecentlyIssuedInformationNotices | |||
IN2001-06Page5of5GenericImplicationsIftrendsofconditionmonitoringdataarenotactivelyinvestigatedwhentheydeviatefromanestablishedbaseline,alicenseemayoverlooksignificantpumpdegradationthatisnotdetected | |||
byperformancetesting.Thisinformationnoticerequiresnospecificactionorwrittenresponse.Ifyouhaveanyquestionsaboutthisnotice,pleasecontactoneofthetechnicalcontactslistedbeloworthe | |||
appropriateOfficeofNuclearReactorRegulation(NRR)projectmanager./RA/LedyardB.Marsh,Chief | |||
EventsAssessment,GenericCommunicationsandNon-PowerReactorsBranchDivisionofRegulatoryImprovementPrograms | |||
OfficeofNuclearReactorRegulationTechnicalcontacts:J.Colaccino,NRRBobHagar,RegionII301-415-2753919-362-0601 E-mail:jxc1@nrc.govE-mail:rch2@nrc.govAttachments:1.ListofReferences | |||
2.ListofRecentlyIssuedInformationNoticesDistribution:INReadingFilePUBLICADAMSACCESSIONNUMBER:ML011070643Template#=NRR-052ÿPubliclyAvailableNon-PubliclyAvailableSensitiveÿNon-SensitiveOFFICETechEditor)REXB:DRIPEMEB:DEEMEB:DENAMEPKleene*RHagar*JColaccino*DTerao*DATE04/09/200104/09/200104/10/200104/18/2001OFFICEEMEB:DEREXB:DRIPD:DEREXB:DRIPNAMEGImbro*JTappert/txkfor*JStrosnider*LDATE04/18/200104/24/200105/03/2001OFFICIALRECORDCOPY | |||
Attachment1Page1of1References1.ShearonHarrisNuclearPowerPlantUnit1,DocketNumber50-400,LicenseeEventReport2000-007-01,"TechnicalSpecificationsViolationDuetoInoperableCharging | |||
SafetyInjectionPump,"datedMarch12,2001.2.NP-4916-R2,ElectricPowerResearchInstitute/NuclearMaintenanceApplicationsCenterLubricationGuide,Revision2,publishedFebruary1995.3.ShearonHarrisNuclearPowerPlantUnit1,DocketNumber05000-400,ReplytoNoticeofViolation(NRCInspectionReportNumbers50-400/00-03,50-400/00-10)dated | |||
March2,2001.4.FederalRegister,Volume64,Number183,"IndustryCodesandStandards;AmendedRequirements,"(10CFRPart50),issuedSeptember22,1999. | |||
______________________________________________________________________________________OL=OperatingLicense | |||
CP=ConstructionPermitAttachment2IN2001-06 Page1of1LISTOFRECENTLYISSUEDNRCINFORMATIONNOTICES_____________________________________________________________________________________InformationDateof | |||
NoticeNo.SubjectIssuanceIssuedto______________________________________________________________________________________2001-05Through-WallCircumferentialCrackingofReactorPressure | |||
===VesselHeadControlRodDrive=== | |||
MechanismPenetration | |||
===NozzlesatOconeeNuclear=== | |||
Station,Unit304/30/01Allholdersofoperatinglicensesforpressurizedwaternuclear | |||
powerreactorsexceptthosewho | |||
haveceasedoperationsandhave | |||
certifiedthatfuelhasbeen | |||
permanentlyremovedfromthe | |||
reactorvessel2001-04NeglectedFireExtinguisherMaintenanceCausesFatality04/11/01Allholdersoflicensesfornuclearpower,research,andtestreactors | |||
andfuelcyclefacilities2001-03IncidentReportingRequirementsforRadiography | |||
Licensees04/06/01Allindustrialradiographylicensees2001-02SummaryofFitness-for-DutyProgramPerformanceReports | |||
forCalendarYears1998and | |||
199903/28/01Allholdersofoperatinglicensesfornuclearpowerreactors,and | |||
licenseesauthorizedtopossess | |||
oruseformulaquantitiesof | |||
strategicspecialnuclearmaterial | |||
(SSNM)ortotransportformula | |||
quantitiesofSSNM2001-01TheImportanceofAccurateInventoryControlstoPrevent | |||
theUnauthorizedPossession | |||
ofRadioactiveMaterial03/26/01Allmateriallicensees2000-17,Supp.2CrackinWeldAreaofReactorCoolantSystemHotLegPiping | |||
atV.C.Summer02/28/01Allholdersofoperatinglicensesfornuclearpowerreactorsexcept | |||
thosewhohasceasedoperations | |||
andhavecertifiedthatfuelhas | |||
permanentlyremovedfrom | |||
reactorvessel2000-22MedicalMisadministrationsCausedbyHumanErrors | |||
===InvolvingGammaStereotactic=== | |||
Radiosurgery(GAMMAKNIFE)12/18/00Allmedicaluselicenseesauthorizedtoconductgamma | |||
stereotacticradiosurgery | |||
treatments | |||
}} | |||
{{Information notice-Nav}} | {{Information notice-Nav}} |
Revision as of 19:39, 6 April 2018
ML011070643 | |
Person / Time | |
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Issue date: | 05/11/2001 |
From: | Marsh L B Operational Experience and Non-Power Reactors Branch |
To: | |
References | |
IN-01-006 | |
Download: ML011070643 (7) | |
UNITEDSTATESNUCLEARREGULATORYCOMMISSIONOFFICEOFNUCLEARREACTORREGULATIONWASHINGTON,D.C.20555-0001May11,2001NRCINFORMATIONNOTICE2001-06:CENTRIFUGALCHARGINGPUMPTHRUSTBEARINGDAMAGENOTDETECTEDDUETO
INADEQUATEASSESSMENTOFOILANALYSIS
RESULTSANDSELECTIONOFPUMP
SURVEILLANCEPOINTS
Addressees
Allholdersofoperatinglicensesfornuclearpowerreactors,exceptthosewhohavepermanentlyceasedoperationsandhavecertifiedthatfuelhasbeenpermanentlyremoved
fromthereactor.
Purpose
TheU.S.NuclearRegulatoryCommission(NRC)isissuingthisinformationnoticetoalertaddresseesthatinadequateassessmentofpumpoilanalysisresults,combinedwith
surveillancetestingwhichdoesnotmonitorallrelevantpumpoperatingconditions,mayallow
severepumpdegradationtogoundetected.Itisexpectedthatrecipientswillreviewthe
informationforapplicabilitytotheirfacilitiesandconsideractions,asappropriate,toavoid
problems.However,thesuggestionscontainedinthisinformationnoticearenotNRC
requirements;therefore,nospecificactionorwrittenresponseisrequired.DescriptionofCircumstancesOnJune19,2000,whiledisassemblingtheCcharging/safetyinjectionpump(CSIP)toreplaceamechanicalseal,ShearonHarrisNuclearPlant(SHNP)personneldiscoveredsignificant
damagetotheoutboardthrustbearing.Furtherexaminationrevealedthatthebabbittmaterial
onthebearingshoesofthismulti-padthrustbearinghadmeltedandre-solidifiedwithinthe
thrustbearingcagearea.Onboththeshoesandthesleeveofthethrustbearing,radialwearin
thedirectionofnormalpumprotationwasindicativeofmetal-to-metalcontactbetweenthetwo
surfaces.Theinboardradialbearingandshaftalsohadminorwear.SHNPstatedina
licenseeeventreport(Reference1)thatthemostprobablecauseofthedamagewasa
momentarylossoflubricationflowtotheoutboardthrustbearing.Aninadequatefill-and-ventof
thepump,whichmayhavecausedamomentaryincreaseintheaxialthrustontheoutboard
thrustbearing,wasalsogivenasapotentialrootcause.ElementalanalysisofaroutinepumpbearingoilsampletakenonSeptember19,1999,usingadirectcurrentplasma(DCP)spectrometer,revealeda40-foldincreaseintheparticlecountin
therangeof5to10micronsovertheprevioussampletakenonMay11,1999.(Theparticle
countincreasedfrom15,800to660,000countsper100millilitersample.)AllothertestedML011070643 IN2001-06Page2of5parameterswerenormal.SHNPreviewedtheElectricPowerResearchInstitute(EPRI)LubricationGuide(Reference2)andconcludedthatthesizerangeofthesewearparticleswas
consistentwithbenignwear.ThebearingoilintheCSIPwasreplacedonDecember21,1999, andSHNPcontinuedsamplingat6-monthintervals.Thenextoilsample,takenon
February23,2000,alsoshowedahighparticlecountinthe5to10micronrange.Trace
amountsofironandtinwerealsodetectedforthefirsttime.Theanalysisofanotheroilsample
takenonJune18,2000,foundthatthelevelsofallparametersweresimilartothelevelsinthe
February23,2000,sample.EachCSIPatSHNPisaPacificModel21/2RLIJ,11-stage,centrifugalpumpmanufacturedbyFlowserveCorporation,formerlyIngersoll-DresserPumpCompany.TheCCSIPisthestandby
pump.Duringtheperiodinwhichhighparticlecountsinthethreeoilsamplesweredetected, theCpumpwasintermittentlyinservicetosupportplantoperations.Surveillancetesting,as
requiredbytheSHNPinservicetestingprogramandtheSHNPTechnicalSpecifications,was
performedontheCpumpduringthisperiod.Inservicetests,includingvibrationmeasurement, wereconductedduringplantoperationonNovember13,1999,andJanuary3,2000,withthe
pumpoperatingatthenormalchargingflowrateofapproximately90gallonsperminute(gpm).
PerformancedatafrombothtestsindicatedtheCCSIPmettheestablishedpumphydraulic
andmechanicalacceptancecriteriaintheAmericanSocietyofMechanicalEngineers(ASME)
CodeforOperationandMaintenanceofNuclearPowerPlants(OMCode),andnoadverse
trendswerenoted.OnApril23,2000,arefuelingoutagetesttosatisfytheSHNPtechnical
specificationswasperformedsuccessfully,withthepumpachievingaflowrateof609gpm.Subsequenttothediscoveryoftheseverelydegradedoutboardpumpthrustbearing,discussionswiththepumpmanufacturerrevealedthatatflowratesbetweenapproximately250
and600gpm,thenetaxialthrustofeachSHNPCSIPpumpisinthedirectionoftheoutboard
thrustbearing.Therefore,SHNPconcludedthatduringnormalplantoperationandsurveillance
testing,theoutboardthrustbearinghadbeeneithernotloadedoronlylightlyloaded.In
addition,SHNPcouldnotassessthecapabilityoftheCCSIPtoperformitsfunctionduringa
small-break,loss-of-coolantaccident,inwhichthepumpaxialthrustwouldhavefullyloadedthe
outboardthrustbearing.InresponsetoanNRCnoticeofviolation(Reference3),SHNPdescribedcorrectivestepseithercompletedorinprogresstoaddressthisissue.Theseincluded(1)counselingoperators
onconsequencesofimproperpumpfill-and-ventoftheCSIP,(2)establishingoilanalysis
criteriaforincreasedlubricantparticlecounts,(3)reinforcingexpectationsfordispositionof
abnormalindications,(4)samplingCSIPlubricatingoilquarterlyinsteadofsemi-annually,
(5)revisingthemaintenanceproceduretoensurethattheCSIPlubricatingoilsystemwill
functionasexpected,and(6)implementingadesignmodificationtoinstalltemperatureand
vibrationproximityprobesoneachCSIP.
IN2001-06Page3of5NRCRequirementsandIndustryGuidanceandPracticesonPumpConditionMonitoringThecurrentrequirementsforinservicetestingofsafety-relatedpumpsarespecifiedinSection50.55aofTitle10oftheCodeofFederalRegulations(10CFR50.55a),"Codesand
Standards."Forplantswhicharerequiredtoupdatetheirinservicetesting(IST)programsafter
September22,2000,whichisoneyearaftertherecentchangeto10CFR50.55a(Reference
4),Subsection(b)(3)requiresthatsafety-relatedpumpsbetestedtothe1995Editionandthe
1996AddendaoftheASMEOMCode.TheCoderequiresthatsafety-relatedpumpsbetested
bienniallyat+/-20%oftheirdesignflowrate,andeverythreemonthsatspecificreferencepoints.
OverallvibrationmeasurementsofeachpumpbearingaretakenasspecifiedbytheCode.The
SHNPISTprogramisinaccordancewithanearlierversionoftheCode,whichrequirespump
testingtobeconductedeverythreemonthsatreferencepointsofoperationreadilyduplicated
duringsubsequenttests.Pumphydraulicperformanceisassessedbycomparingcurrent
performancewithreferencevaluesestablishedwhenthepumpisknowntobeoperating
acceptably.Pumpmechanicalperformanceisassessedlikehydraulicperformance,unlessthe
specifiedmultipleofthemeasuredoverallvibrationreferencevalueexceedstheabsolute
vibrationacceptancecriterion.NeithertheCodenortheregulationsrequireanyspecificpumpconditionmonitoringactivitiestobeperformedonsafety-relatedpumps.However,theNRChasobservedduringinspection
activitiesthatmanyUScommercialnuclearpowerplantshavesometypeofcondition
monitoringprogramfortheirrotatingmachinery.Theseprogramsusuallyincludebothsafety- relatedandnon-safety-relatedequipment.Becausenoregulationscovertheseprograms,the
testingperformed,theexaminationscompleted,andtheacceptancecriteriausedforeach
conditionmonitoringactivityvarywidely.TheEPRILubricationGuideincludesinformationonthetestingandanalysisoflubricants.Theguideidentifiesparticlesizeandwear-metalcontentaskeypropertiestoanalyze.Theguide
alsoprovides"classic"warninglimitsforcertainmeasuredproperties.Theguidedoesnot
recommendaspecificwarninglimitforparticlecount.However,theguideemphasizestrending
criticalpropertiesofaspecificapplicationandestablishingappropriatewarninglimits.When
theselimitsareexceededandtheresultsareverified,theguiderecommendsoilreplacement
andfurtherstudyifnecessary.TheNRChasauthorizedalternativestotheCodevibrationrequirementsbasedontheperformanceofpumpconditionmonitoringactivities.Forexample,aspartofanalternativeto
theCodevibrationacceptancecriterion,onefacilitycommittedtoimplementaplant-specific
pumpconditionmonitoringprogramforcertainsafety-relatedpumps.TheNRChasdetermined
thatthisproposedalternativedemonstratesanacceptablelevelofqualityandsafety.
IN2001-06Page4of5DiscussionAkeyfactorinthefailuretodiscoverthedamagedbearingbeforedisassemblywasnotactivelypursuingtherootcauseoftheabnormallyhighparticlecountintheSeptember19,1999,oil
sample.TheEPRIguideimpliesthatparticleslessthan10micronsinsizearegeneratedfrom
"benignwear."Theguidedoesnotdiscussthesignificanceofchangesinwearparticle
concentration.However,theguidedoesdiscusstrendingofparameters.SHNPperformed
spectroscopicanalysisofeachsampleandtrendedtheresultsofthesetests.Thelowweight
percentofthewearparticleswasapparentlythereasonwhytheelementalanalysisdidnot
detectthepresenceofbearingmaterial.Ferrographyandelectronmicroscopicscan
examinationwereconductedafterthediscoveryofthebearingdegradationandthereforewere
notafactorindiagnosingtheelevatedparticlecount.SHNPelectedtocontinuewitharoutine
oilsamplingscheduledespitethehighparticlecountandthelackofaplausiblerootcausefor
thiscondition.Amoreaggressiveoilsamplingschedule(e.g.,weekly)wouldlikelyhave
revealedtheseverelydegradedoutboardthrustbearingseveralmonthsbeforethepumpwas
disassembled.Inserviceandtechnicalspecificationsurveillancetestingdidnotindicatethattheoutboardthrustbearingwasseverelydamaged.Thepurposeofpumpinservicetestingistoidentify
degradationbeforethepump'sperformanceofitssafety-relatedfunctionisimpaired.Forthe
chargingpumpsattheSHNP,thepurposeoftechnicalspecificationtestingistoverifythatthe
pumpwilldeliveraspecificflowattherequiredtotaldevelopedhead.Thefailureofbothtests
toindicatebearingdegradationappearstohavebiasedthedecisiontonotinvestigatethe
elevatedparticlecount.Informationprovidedbythevendorrevealedareversalinthedirectionofthepumpaxialforceasafunctionofthepumpflowrate.ThispumpdesigncharacteristicwasunknowntoSHNP
personnelbeforetheydiscoveredtheseverelydegradedbearingandthentalkedwiththe
vendor.TheCodedoesnotrequireSHNPtoaccountforthisdesignconditionthroughtesting.
Thetechnicalspecificationfullflowtestafterthefirstdetectionofthehighparticlecountneither
detectedthisconditionnorcausedacatastrophicfailureofthepump.Thisissueillustratesthat
theassessmentofsafety-relatedpumpperformanceisdependentnotonlyonverifying
successfulsurveillancetesting,butalsoonunderstanding(1)pumpandsystemdesignand
performancecharacteristics,(2)performancetestingresults,and(3)theresultsofcondition
monitoringactivitiesandtheircorrelationwithknownpumpdesigncharacteristicsand
performancetestresults.
IN2001-06Page5of5GenericImplicationsIftrendsofconditionmonitoringdataarenotactivelyinvestigatedwhentheydeviatefromanestablishedbaseline,alicenseemayoverlooksignificantpumpdegradationthatisnotdetected
byperformancetesting.Thisinformationnoticerequiresnospecificactionorwrittenresponse.Ifyouhaveanyquestionsaboutthisnotice,pleasecontactoneofthetechnicalcontactslistedbeloworthe
appropriateOfficeofNuclearReactorRegulation(NRR)projectmanager./RA/LedyardB.Marsh,Chief
EventsAssessment,GenericCommunicationsandNon-PowerReactorsBranchDivisionofRegulatoryImprovementPrograms
OfficeofNuclearReactorRegulationTechnicalcontacts:J.Colaccino,NRRBobHagar,RegionII301-415-2753919-362-0601 E-mail:jxc1@nrc.govE-mail:rch2@nrc.gov:Attachments:1.ListofReferences
2.ListofRecentlyIssuedInformationNotices
IN2001-06Page5of5GenericImplicationsIftrendsofconditionmonitoringdataarenotactivelyinvestigatedwhentheydeviatefromanestablishedbaseline,alicenseemayoverlooksignificantpumpdegradationthatisnotdetected
byperformancetesting.Thisinformationnoticerequiresnospecificactionorwrittenresponse.Ifyouhaveanyquestionsaboutthisnotice,pleasecontactoneofthetechnicalcontactslistedbeloworthe
appropriateOfficeofNuclearReactorRegulation(NRR)projectmanager./RA/LedyardB.Marsh,Chief
EventsAssessment,GenericCommunicationsandNon-PowerReactorsBranchDivisionofRegulatoryImprovementPrograms
OfficeofNuclearReactorRegulationTechnicalcontacts:J.Colaccino,NRRBobHagar,RegionII301-415-2753919-362-0601 E-mail:jxc1@nrc.govE-mail:rch2@nrc.govAttachments:1.ListofReferences
2.ListofRecentlyIssuedInformationNoticesDistribution:INReadingFilePUBLICADAMSACCESSIONNUMBER:ML011070643Template#=NRR-052ÿPubliclyAvailableNon-PubliclyAvailableSensitiveÿNon-SensitiveOFFICETechEditor)REXB:DRIPEMEB:DEEMEB:DENAMEPKleene*RHagar*JColaccino*DTerao*DATE04/09/200104/09/200104/10/200104/18/2001OFFICEEMEB:DEREXB:DRIPD:DEREXB:DRIPNAMEGImbro*JTappert/txkfor*JStrosnider*LDATE04/18/200104/24/200105/03/2001OFFICIALRECORDCOPY
Attachment1Page1of1References1.ShearonHarrisNuclearPowerPlantUnit1,DocketNumber50-400,LicenseeEventReport2000-007-01,"TechnicalSpecificationsViolationDuetoInoperableCharging
SafetyInjectionPump,"datedMarch12,2001.2.NP-4916-R2,ElectricPowerResearchInstitute/NuclearMaintenanceApplicationsCenterLubricationGuide,Revision2,publishedFebruary1995.3.ShearonHarrisNuclearPowerPlantUnit1,DocketNumber05000-400,ReplytoNoticeofViolation(NRCInspectionReportNumbers50-400/00-03,50-400/00-10)dated
March2,2001.4.FederalRegister,Volume64,Number183,"IndustryCodesandStandards;AmendedRequirements,"(10CFRPart50),issuedSeptember22,1999.
______________________________________________________________________________________OL=OperatingLicense
CP=ConstructionPermitAttachment2IN2001-06 Page1of1LISTOFRECENTLYISSUEDNRCINFORMATIONNOTICES_____________________________________________________________________________________InformationDateof
NoticeNo.SubjectIssuanceIssuedto______________________________________________________________________________________2001-05Through-WallCircumferentialCrackingofReactorPressure
VesselHeadControlRodDrive
MechanismPenetration
NozzlesatOconeeNuclear
Station,Unit304/30/01Allholdersofoperatinglicensesforpressurizedwaternuclear
powerreactorsexceptthosewho
haveceasedoperationsandhave
certifiedthatfuelhasbeen
permanentlyremovedfromthe
reactorvessel2001-04NeglectedFireExtinguisherMaintenanceCausesFatality04/11/01Allholdersoflicensesfornuclearpower,research,andtestreactors
andfuelcyclefacilities2001-03IncidentReportingRequirementsforRadiography
Licensees04/06/01Allindustrialradiographylicensees2001-02SummaryofFitness-for-DutyProgramPerformanceReports
forCalendarYears1998and
199903/28/01Allholdersofoperatinglicensesfornuclearpowerreactors,and
licenseesauthorizedtopossess
oruseformulaquantitiesof
strategicspecialnuclearmaterial
(SSNM)ortotransportformula
quantitiesofSSNM2001-01TheImportanceofAccurateInventoryControlstoPrevent
theUnauthorizedPossession
ofRadioactiveMaterial03/26/01Allmateriallicensees2000-17,Supp.2CrackinWeldAreaofReactorCoolantSystemHotLegPiping
atV.C.Summer02/28/01Allholdersofoperatinglicensesfornuclearpowerreactorsexcept
thosewhohasceasedoperations
andhavecertifiedthatfuelhas
permanentlyremovedfrom
reactorvessel2000-22MedicalMisadministrationsCausedbyHumanErrors
InvolvingGammaStereotactic
Radiosurgery(GAMMAKNIFE)12/18/00Allmedicaluselicenseesauthorizedtoconductgamma
stereotacticradiosurgery
treatments