ML17241A489

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LER 99-004-00:on 990912,noted That MSSV Surveillance Was Outside of TS Requirements.Caused by Setpoint Drift.Subject MSSVs Are Being Refurbished & Retested Prior to Unit Startup from SL1-16 Refueling Outage.With 991007 Ltr
ML17241A489
Person / Time
Site: Saint Lucie NextEra Energy icon.png
Issue date: 10/07/1999
From: FREHAFER K W, STALL J A
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-99-219, LER-99-004-01, NUDOCS 9910140083
Download: ML17241A489 (10)


Text

MMJ;NVUlCY'~~~~REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9910140083 DOC.DATE:

99/10/07NOTARIZED:

NOFACIL:50-335 St.LuciePlant,Unit1,FloridaPower&LightCo.AUTH.NAME.'AUTHORAFFILIATION FREHAFER,K.W.

FloridaPower&LightCo.STALL,J.A.

,FloridaPower&LightCo.RECIP.NAME RECIPIENT AFFILIATION DOCKET¹05000335

SUBJECT:

LER99-004-00:on 990912,noted thatMSSVsurveillance wasoutsideofTSrequirements.

Causedbysetpointdrift.SubjectMSSVsarebeingrefurbished

&retestedpriortounitstartupfromSLl-16refueling outage.With991007ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR IENCLISIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:'ECIPXENT IDCODE/NAME LPD2-2INTERNAL:

ACRSNRR/DIPM/IOLB NRR/DSSA/SPLB RES/DRY/OERAB COPIESLTTRENCL1111111111RECIPIENT IDCODE/NAME GLEAVES,W NRR/DRXP/REXB RES/DET/ERAB RGN2FILE01'OPIESLTTRENCL1111111111EXTERNAL:

LSTLOBBYWARDNOACPOORE,W.NRCPDR111111LMXTCOMARSHALLNOACQUEENER,DS NUDOCSFULLTXT111111NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTDESK(DCD)ONEXTENSION 415-2083TDOCUMENTCONTRCFULLTEXTCONVERSION REQUIREDTOTAL,NUMBEROFCOPIESREQUIRED:

LTTR16ENCL16 FloridaPowerStLightCompany,6351S.OceanDrive,JensenBeach,FL34957FPLOctober7,1999L-99-21910CFR$50.73U.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Re:St.LucieUnit1DocketNo.50-335Reportable Event:1999-004-00 DateofEvent:September 12,1999MainSteamSafetyValvesSurveillance OutsideTechnical Secification Reuirements TheattachedLicenseeEventReport1999-004isbeingsubmitted pursuanttotherequirements of10CFRf50.73toprovidenotification ofthesubjectevent.Verytrulyyours,J.A.StallVicePresident St.LucieNuclearPlantJAS/EJW/KWF Attachment cc:RegionalAdministrator, USNRC,RegionIISeniorResidentInspector, USNRC,St.LucieNuclearPlant99i0140083 991007PDRADOCK05000335PDRanFPLGroupcompany NRCFORM366I6.1999)U.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/characters foreachblock)APPROVEDBYOMBNO.3160-0104 EXPIRES06/30/2001 Estimated burdenperresponsetocomplywiththismandatory information collection request:50hrs.Reportedlessonsteamedareincorporated intothelicensing processandfedbacktoindustry.

Forwardcommentsregarding burdenestimatetotheRecord.TAanagement Branch{TWF33),U.S.NuclearRegulatory Commission, Washington, Dc205554001, andtothePapenvork Reduction Project(31504104j, OfficeofManagement andBudget,Washington, DC20503.Ifaninformation collection doesnotdisplayacurrently validOMBcontrolnumber,theNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,theInformation collection.

FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335PAGE(3)Page1of5TITLE(4)MainSteamSafetyValvesSurveillance OutsideTechnical Specification'equirements MONTHDAYYEAREVENTDATE(6)LERNUMBER(6)YEARSEQUENTIAL REVISIONNUMBERNUMBERREPORTDATE(7)MONTHDAYFACIUTYNAMEOTHERFACILITIES INVOLVED(8)DOCKETNUMBER091219991999-004-0010071999FACIUTYNAMEDOCKETNUMBEROPERATING MODE(9)POWERLEVEL{10)07020.2201(b)20.2203(a)

{1)20.2203(a)(2)

(i),20.2203(a)(2)(v) 20.2203(a)(3){I)20.2203{a)

(3)(ii)X50.73(a)(2)(i) 50.73(a)(2)(ii)50.73(a)(2)(iii)THISREPORTISSUBMITTEDPURSUANTTOTHEREQUIREMENTS OF10CFR5:(Chockonoormore)(11)50.73{a)(2)(viii) 50.73(a)(2)(x)73.7120.2203{a)

(2)(ii)20.2203(a)

(2)(iii)20.2203(a)

{2)(iv)20.2203(a)

(4)50.36(c){1) 50.36(c)(2)50.73(a){2)(iv)50.73(a)(2)

(v)50.73(a)(2){vii)OTHERSpecifyInAbstractbeloworinNRCForm366ANAMELICENSEECONTACTFORTHISLER{12)TELEPHONE NUMBERunaludaAraaCoda)KennethW.Frehafer, Licensing Engineer(561)467-7748COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT13)CAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE ToEPIXCAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE ToEPIXSUPPLEMENTAL REPORTEXPECTED(14)YES(tfyes,c'omplete EXPECTEDSUBMISSION DATE).XNoEXPECTED,SUBMISSION DATE(16)MONTHDAYABSTRACT/Limitto1400spaces,i.e.,approximately 15singlewpaced typewritten lines/(16)OnSeptember 12,1999,St.LucieUnit1wasinMode1andholdingat.approximately 70percentreactorpowerfortesting'f themainsteamsafetyvalves(MSSVs)inaccordance withproceduze 1-MSP-08.07, "MainSteamSa'fetySetpointSurveillance."

ThreetrainAandonetrainBMSSVsliftedlow,outsideoftherequiredTechnical Specification pressuresetpointrangeof+/-1percent.Priortotesting,thereactortripsetpoints werereducedtoallowcontinued operation withtwoMSSVspertrainoutofservice.ThesetpressureofoneofthetrainAMSSVswasresettoallowcontinued operation.

TheapparentcauseoftheMSSVsurveillance failureswassetpointdrift.PerASMEcodeconsiderations, aformalrootcauseisnotrequired.

Thesafetysignificance ofthelowas-foundMSSVsetpoints wasevaluated andfoundtobeinsignificant.

ThesubjectMSSVsarebeingrefurbished andretestedpriortounitstartupfromtheSL1-16refueling outage.FPLisconsidering whetherachangetotheSt.LucieTechnical Specifications orTSbasesisappropriate toaddressthedifferences betweenNUREG-1432 andtheSt.~LucieTechnical Specifications concerning as-foundandas-leftsafetyreliefsetpoints.

NRCFORM3BBIB.1999)

NRCFORM366A(6-1998)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBER1999-004-00PAGE(3)Page2of5TEXT(Ifmorespaceisreriuired, useadditional copiesofIVRCForm366A)(17)Description oftheEventOnSeptember 12,1999,St.LucieUnit1wasinMode1andholdingatapproximately 70percentreactorpowerfortestingofthemainsteamsafetyvalves(MSSVs)(EIIS)SB)RV) duringthedownpowex fortheSL1-16refueling outage.Thefollowing MSSVsliftedoutsideoftheirTechnical Specifications (TS)requiredpressurerange.Additionally V8213liftedoutsideofthe+/-3%ASMEcodeallowedrangeby0.6psiglow.Thissurveillance testingoftheMSSVs'etpoints wasperformed inaccordance withprocedure 1-HSP-08.07, "HainSteamSafetySetpointSurveillance."

ValveSepointV8201V8202V8211V8213TrainMeasuredLiftPressure(psia)986.9982.91025.51008.7TSLimit1000+/-1%1000+/-1()1040+/-1()1040+/-1'hDeviation FromTSLimit(())1'1-1071-1.45-3013MSSVsV8201,V8211,and,V8213 wereleftinoperable andoutofserviceatthecompletion oftesting.V8202wasrestoredtoOPERABLEstatsbysetpointadjustment withintheactiontimeofTechnical Specification 3.7.1.1.PriortotestingtheMSSVs,thereactortripsetpoints hadbeenreducedtoallowcontinued operation withtwoMSSVspertrainoutofservicepexworkordex(WO)98023939-02.

Nomorethantwovalvespertrainwereoutofserviceandthereactortripsetpoints wereproperlyadjustedinaccordance withTe'chnical Specification 3.7'.1,therefore therewerenooperability concerns.

CauseoftheEventTheas-foundsetpressuredeviations wererelatively minorandsimilartothosefoundinpastcycles.Theapparentcauseissetpointdriftand/ortheuseofthenewtestmethods.Asdescribed below,aformalrootcauseisnotrequiredbyASME/ANSI OM-1987,partl.PerASME/ANSI OM-1'tt1.3.3.1(e)(2) andCodeInterpretation 92-8,aClass1pressurereliefvalvewithanas-foundsetpointoutsidetheacceptance rangeofthesetpointontheminussideisnotconsidered afailure.Asaconsequence, additi.onal testingforvalvesfailingoutsidethenegativeacceptance criteriaisnotrequiredbytheASMECode.FPLqualityinstruction (QI)11-PR/PSL-7, "ControlofCodeSafetyandReliefValves,"containsadditional criteriawithin95.5.3thatgenerally requiresadditional testingforvalvesfailingthenegativetolerance criteria.

TheQIcriteriaarebasedontheadversesystemfunctional issuesresulting fromreliefvalveseatleakageandpremature lift.However,pertheQI,thecriteriaforadditional testingofvalvesfaili.ngthenegativetolerance acceptance criteriamaybewaivedoralteredbasedonanevaluation oftheas-foundtestpressure, valveinspection, systemrequirements andhistori.cal records.Theexpansion oftestingscopeduetothefailureofV8213waswaivedbasedonthesmallamountofdeviation (3.13%vs.3%),theacceptable resultsoftheother'alve testswithrespecttoASMENRCFORM388A18.1898)

NRCFORM366AI6-1888)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBER1999-004-00PAGE(3)Page3of5TEXTllfmorespecsisrequired, useadditionelcopiesofNRCForm366A)(17)CauseoftheEvent(cont'd)criteria, theabsenceofrecentproblemswithMSSVseatleakageandpremature lift,andtheinsignificant effectofasmallnegativesetpressuredeviation inahighbankMSSVreliefvalve.TheMSSVsarebeingrefurbished andretested.

AnalysisoftheEventThiseventisreportable under10CFR50.72(a)(2)(i)(B)as"anyoperation orcondition prohibited theplant'sTechnical Specifications."

TheSt.LucieUnit1Technical Specifications differfromNUREG-1432r "Standard Technical Specification Combustion Engineering Plants,"inthatanas-foundMSSVsetpointtolerance isnotincludedintheSt.LucieTechnical Specifications.

FPLisconsidering whetherachangetotheSt.LucieTechnical Specifications ozTSbasesisappropriate toaddressthisTechnical Specification difference.

AnalysisofSafetySignificance TheMSSVsmustopentoprovideoverpressure protection forthesteamgenerators andreliefcapacitytoremovedecayheat.TheMSSVsareclassified asSafety-Related, QualityGroupBcomponents.

PerTStable3.7-1themaximumallowable powerlevelhightripsetpointwithtwoinoperable steamlinesafetyvalvesoneitheroperating steamgenerator is79.8%EffectonSafetAnalsesValvesV8201,V8202,V8211andV8213liftedoutsidetheTSliftsettingtolerance limitof+/-1percent.However,theseliftsettingfailuresweregreaterthanthe-1percentlimit.ValvesV8205andV8216liftedwithinthetolerance limitspecified intheTS.Itwillbeassumedforthepurposeofthisevaluation*

thatalltheremaining valveswouldhaveliftedwithintheirtolerance limits.TheonlyFSARanalyzedeventsthatcouldpotentially beaffectedbythedeviations intheMSSVsetpoints arethelossofexterhalload(LOEL)andthesmallbreak,LOCA(SBLOCA).

Theloss.ofexternalloadevent,including thecaseofinoperable MSSVs,reliesontheMSSVstoreleasethesystemenergysoastopreventtheprimaryandthesecondary sidepressures fromexceeding theoverpzessurization criteria.

Theanalysisofthiseventassumesconservatively thattheMSSVsbegintoopenattheTSallowedmaximumliftpressurecorresponding toatolerance of+1percent.Openingofthevalvesatapressurelowerthanthatassumedinthesafetyanalysiswouldbebeneficial forthistransient andtheresultswouldremainboundedbytheFSARresults.IntheanalysisofthesmallbreakLOCAevent,itis-assumedthattheMSSVsbegintoopenataliftpressurecorresponding toatolerance of+3percent.Theas-foundsetpressures therefore would,nothaveanyadverse'impactonthesmallbreakLOCAanalysisresults,aspresented intheFSAR.OtherFSAReventsincluding thesteamgenerator tuberupture(SGTR)eventarenotimpactedbythevariations intheMSSVliftpressure.

TheSGTReventanalyzedintheFSARconservatively assumestheopeningoftheatmospheric dumpvalves(ADVs)toNRCFORM3BBA(6-1888)

NRCFORM366AIs-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.I'IUCLEAR REGULATORY COMMISSION FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBER1999-004-00PAGE(3)Page4of5TEXT(Ifmorespeceisrequired, useedditionelcopiesofNRCForm366AJ(17)AnalysisofSafetySignificance (cont'd)releasethesteamfromtherupturedsteamgenerators.

Theidentified MSSVs'etpoint pressuredeviations thuswouldnotimpacttheFSARconclusions forthisevent.'heopeningofMSSVsatpressures lowerthantheliftpressurecorzesponding to-1percenttolerance isthusdetermined to'havenoadverseimpactonthesafetyanalysis, including deviations outside-3.percent.

Amuchlowernegativevalve'tolerance limit,althoughacceptable fromsafetyanalysisconsiderations, mayhaveoperational impactasthemargintooperating pressuregetsreduced.TheMSSVs's-found setpressurevalues(specified above)wereoutsidethetolerance limitsspecified intheSt.LucieUnit1Technical Specification 3.7.1.1.Thisdegradedcondition howeverdidnotcompromise plantsafety.Theevaluation performed usingtheas-foundsetpoints concludes that,Cycle15operation hadremainedwithinthedesignbasisoftheplantforallanalyzedFSARevents.Nosafetycriteriawouldhavebeenviolatedduetotheidentified condition oftheMSSVs.SeointDriftConsiderations ThebelowchartshowstheMSSVtestsinthelast3cyclesforunit1.Not'allofthevalvesweretestedduringthesecycles.TheAs-Found()Failurecolumnisshownforthecyclesthatwereevaluated.

Theyrepresent thepercentage fromnameplate setpointthatthevalvewasoutoftolerance.

Thenoneinthecolumnmeans,thatthetestwassatisfactory.

ThepercentDriftbetweenCycles.columnisthepercentage changethatthevalveexperienced overonecycletakenfromthe2"eas-leftsetpointtestandthenextas-foundtestofthevalve.IValveS/NUnit1N55128-00-0001 N55128-00-0002 N55128-00-0003 N55128-00-0004 N55128-00-0005 N55128-00-0006 N55128-00-0007 N55128-00-0008 N55128-00-0009 N55128-00-0010 N55128-00-0011 N55128-00-0011 N55128-00-0012 N55128-00-0013 N55128-00-0014 N55128-00-0015 N55128-00-0016 Date19961996199619961996199619961996-199619961995199919961996199619961996As-Pound%'ailurenonenone1.4none-1.52~1.831.932.54nonenonenone-1.45none1.951.271.17noneDate1999199919971999199719971997199619971999199719971999As-Pound%Pailure-1.71-1.31-1.03none1.62nonenone1.37none-3.13nonenonenone%Driftbetweencles-1.62-1.93-1.12-0.201.52-.50-.191.17-2.13-~68-3.50-1.35.10-0.87 NRCFORM366A(8-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S:NUCLEARREGULATORY COMMISSION FACILITYNAME{1)St.LucieUnit1DOCKETNUMBERI205000335LERNUMBERI6)SEQUENTIAL REVISIONNUMBERNUMBER1999-004-00PAGEI3)Page5of5TEXT(Ifmorespaceisrequired, useadditional copiesofNRCForm3MAJ(17)AnalysisofSafetySignificance (cont'd)ThesedataarefromtheReliefValveDatabase.

Thisevaluation doesnottakeintoaccounttheinstrument inaccuracies orthedifference inreadingsbetween'the 1"and2""testsdonetoacceptthevalves.Thetestmethodology waschangedforUnit1forthe1999testing.Theplantstartedusingcomputeroperatedtestmachinevs.thepreviousmanualtestmethod.Bothtesttechniques usealiftingdevicebutthenewersystem'sramprateandsetpointinterpretation arelesssubjective andoperatordependent whichprovideformoreconsistent andaccuratereadings.

FPLconcluded thatthereliefvalvessetpointdriftismostlyscattered datawithnodominanttrendingsetpointdriftforanyvalveoverthecyclesanalyzed.

Therefore, thereisnoconcernpertaining tothedownwarddriftoftheMSSVsetpoints.

Basedontheabove,thiseventhadnoimpactonthehealthandsafetyofthepublic,Corrective Actions1.ThesubjectMSSVsarebeingrefurbished byWyleLabsviaWO98018487.

2.ThesubjectMSSVswillbereworkedandretestedperWO98018488.

3.FPLisconsidering achangetotheSt.LucieTechnical Specifications toaddressthedifferences betweenNUREG-1432 andtheSt.LucieTechnical Specifications concerning as-foundandas-leftsafetyreliefvalvesetpoints.

Additional Information FailedComonentsIdentified BasedonASMEcodeconsiderations, therewerenoMSSVtestfailures.

SimilarEventsLER50-389/1999-004-00 and50-389/1999-004-01, "AsFoundCycle10Pressurizer SafetyValveSetpoints OutsideTechnical Specification Limits,"wasissuedforUnit2pressurizer codesafetysurveillance failures.

NRCFORM3BBAIB.1898) r~