ML18040A167

NMP Nine Mile Point Unit 1 Nuclear Power Station Rept of RPV FW & CRD Return Line Nozzle Exams Performed for NUREG-0619...at Culmination of Refueling Outage 13 Which Ended on 950404.

ML18040A167
Person / Time
Site:	Nine Mile Point
Issue date:	09/29/1995
From:	NIAGARA MOHAWK POWER CORP.
To:
Shared Package
ML18040A166	List: ML18040A165 ML18040A167
References
RTR-NUREG-0619, RTR-NUREG-619 NUDOCS 9510100318
Download: ML18040A167 (42)

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NIAGARAMOHAWKPOWERCORPORATION NINEMILEPOINTUNIT1NUCLEARPOWERSTATIONREPORTOFREACTORPRESSUREVESSELFEEDWATERANDCONTROLRODDMVERETURNLINENOZZLEEXAMINATIONS performed forNUREG0619BWRFEEDWATER NOZZLEANDCONTROLRODDRIVERETURNLINENOZZLECRACKINGattheculmination ofREFUELING OUTAGENO.13whichendedonApril4,1995Thisdocumentcompleted SEPTEMBER 29,19959510100318 951003PDRADOCK05000220,,P...,PDR,,

l~Q NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)TABLEFCNTENTSINTRODUCTION

...................................

1ACKGROUND

....................................1 BRESULTSOFEXAMINATIONS

.........................

2MODIFICATIONS ANDSYSTEMCHANGES................

2STARTUP/SHUTDOWN CYCLES........................

3LEAKAGEMONITORING

.............................

3VlaARYe~~~~~~~~~~~~~~~~~'o~~~~~~~~~~~~~~~~~~~~3SEFERENCES e~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~o~~~~~5RAPPENDICES A.FEEDWATER ANDCONTROLRODDRIVERETURN.....7LINENOZZLEINSPECTION RESULTSB.MODIFICATIONS ORSYSTEMCHANGESTHAT.......15AFFECTFEEDWATER FLOWORTEMPERATUI&

C.ULTRASONIC EXAMINATION TECHNIQUES

..........

16

~'NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)I.INTRODUCTION Thisreportprovidestheinformation requiredbyNUREG-0619, "BWRFeedwater NozzleandControlRodDriveReturnLineNozzleCracking" (November 1980).Thereportincludes:

Asummaryofmethodsused,theresultsoftheinservice inspections ofthefeedwater andcontrolroddrivereturnline(CRDRL)nozzlesandfeedwater spargerflowholesandweldsinspargerarmsandtees,theeffectsofmodifications orsystemchangesonfeedwater flowortemperature, thenumberofstartup/shutdown cycles,andadiscussion ofthermalsleeveleakagemonitoring.

Theinspections wereperformed bytheGeneralElectricNuclearEnergyCorporation (GE-NE)ofSanJose,California.

H.BACKGROUND NineMilePointUnit1isa620MweBoilingWaterReactor(BWR)whichbeganoperation inNovember1969andhasbeeninserviceforapproximately 26years.Duringthe1977Refueling Outage,NiagaraMohawk(NMPC)removedtheoriginally-installed loose-fit feedwater spargersandreplacedthemwithanimproveddesign(single-piston ring/flow baffleseal).Thefourfeedwater nozzleswereultrasonically (UT)examinedfromthereactorvesselexteriorusingprocedures andtechniques developed byGeneralElectric(GE).ThisUTexamination established abaselineforsubsequent nozzleexaminations.

AsrequiredbyNUREG-0312, "InterimTechnical ReportonBWRFeedwater NozzleandControlRodDriveReturnLineNozzleCracking,"

aninservice UTanddyepenetrant (PT)examination ofthefourfeedwater nozzleswasperformed byGEduringthe1979refueling outage.Nosignificant changesfromthebaselineexaminations wereobserved.

Inaddition, theReactorWaterCleanup(RWCU)returnlinewasreroutedtothefeedwater lines.InNiagaraMohawk'sresponsetoNUREG-0619, datedDecember29,1980,wecommitted toaprogramofperiodicinspections ofthefeedwater andcontrolroddrivereturnlinenozzles.Thefeedwater nozzleUTinspection wastobeperformed everyotherrefueling outageandthevisualinspection (VT)ofthefeedwater spargerswastobeperformed everyfourthrefueling outage,commencing withthe1981outage.ThePTinspection ofthefeedwater andcontrolroddrivereturnlinenozzleswastobeperformed everysixthrefueling outageorevery90startup/shutdown cycles,whichever occurredfirst.ThePTInspection intervals commenced withthe1979refueling outage,duringwhichthebaselinefeedwater nozzlePTinspections weremade.

I NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXA1VHNATIONS 1995REFUELING OUTAGE(RFO-13)H.BACKROUNDCont'dDuringthe1988Refueling Outage(RFO-11),

theNMPCNuclearQualityAssurance Department generated Corrective ActionRequest88.2039-01 todocumentandresolvediscrepancies inpreviousoutages'eedwater nozzleexamination data.Alsogenerated duringthe1988outagewastheRestartActionPlan(RAP).OneoftheRAPspecificissuesaddressed thelackoffullvolumecoverageonfeedwater nozzlesasrequiredbyNUREG-0619.

Allofthecorrective actionsforbothoftheseissueswereidentified andimplemented duringthe1988outage.The1988UTexaminations ofthefeedwater nozzlesperformed bytheNuclearEnergyServicesCo.(NES)revealedindications thatwouldrequiremonitoring duringthefollowing refueling outage.TheUTexaminations conducted duringRFO-12in1993offeedwater nozzle"A"wereperformed byGeneralElectricNuclearEnergy(GE-NE).Theresultsoftheseexaminations werepresented inNMPC'ssubmittal ofAugust25,1993(NMP1L0777)whichindicated norecordable indications andresolvedthoseindications identified in1988duringRFO-11asrequiring additional monitoring.

Visualexaminations (VT)ofthefeedwater spargerflowholesandweldsinspargerarmsandteeswereperformed byGE-NEduringRFO-11in1988andagainduringRFO-12in1993,Theseexaminations indicated noreportable indications.

III.RULTSOFEXAMINATI NTheinspections conducted duringRFO-13in1995wereperformed withtheUltrasonic Test(UT)methodbyGE-NEwhichindicated noreportable indications.

TheseUTexaminations utilizedtheGERIS2000automated systemandmanualUTpickupsoftheRPVnozzlesonfour(4)feedwater andthecontrolroddrivereturnlinenozzles.Theresultsoftheseexaminations andasummaryofallpreviousexaminations arepresented inAppendixAofthisreport.IV.MODIFICATIONS NUREG-0619 requireslicensees toreportallmodifications orsystemchangesthataffectfeedwater flowortemperature andtoconsiderthesechangesinpredicting futurecrackingtendencies.

Sinceour1988outageNUREG-0019 report,therehavebeennomodifications orsystemchangesthataffectfeedwater flowortemperature.

AppendixBtothisreportsummarizes allapplicable physicalandprocedural modifications implemented atNineMilePointUnit1since1977whichaffectfeedwater flowortemperature.

NMPIRPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)V.TARTUP/HUTDWNCYCLThefeedwater andcontrolroddrivereturnlinenozzleshaveexperienced 171startup/shutdown cyclessinceinitialplantoperation.

Thecontrolroddrivereturnlinenozzlehasexperienced only63startup/shutdown cyclessincethePTexamination in1979.Table1providesfurtherdataonthenumberofstartup/shutdown cyclesfromoutagetooutagesince1977.VI.LEAKAGEMNITRINGNiagaraMohawkhasnotinstalled anon-linebypassleakagemonitoring systematNineMilePointUnit1(NMP1).Thethermalsleevedesignincludesflowbafflesthatpreventmixingofthehotreactorwaterandthecolderfeedwater inthenozzleannulus.NUREG-0619, Section4.3.2.4specifically exemptsNMP1fromthisrequirement.

VII.8UMMARYThenondestructive examinations performed duringthe1995Refueling Outage,tu'0-13,identified noreportable indications thatwillrequiremonitoring inaccordance withNUREG-0619.

NMPCanticipates tocontinueutilizing anautomated inspection methodsuchastheGEGERIS2000automated systemforfutureoutagesasdescribed inNMPC'ssubmittal ofJune23,1994(NMP1L0829).

I NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)TABLEINUMBEROFSTARTUPHUTDWNCYCLATNINEMILEINTT1PERIODNUMBEROFCYCLESDURINGPERIODCUMULATIVE 1969InitialStartup-1977Refueling Outage1977Refueling Outage-1979Refueling Outage1979Refueling Outage-1981Refueling Outage1981Refueling Outage-1983Safe-EndOutage1983Safe-EndOutage-1986Refueling Outage1986Refueling Outage-1987Feedwater Transient Outage(1988Refueling Outage)1988Refueling OutageRFO-111993Refueling OutageRFO-121993Refueling OutageRFO-121995Refueling OutageRFO-13951317141795108125127141149166171

VIII.R~RPERRNC NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)2.BWRFeedwater NozzleandControlRodDriveReturnLineNozzleCracking, NUREG-0619, U.S.NuclearRegulatory Commission, November1980.NMPCLetter,D.P.DisctoR.C.Haynes,U.S.NuclearRegulatory Commission, datedJanuary4,1982(

Subject:

Inservice Inspections ofFeedwater NozzlesandSpargersPerformed Duringthe1981Refueling Outage).3.4,5.6.NESLetter,T.J.KochtoT.W.Roman,datedMarch4,1983(

Subject:

February, 1983Feedwater NozzleInnerRadiusExams).NESLetter,W.R.DownstoT.W.Roman,datedJune27,1984(

Subject:

April,1984Feedwater NozzleInnerRadiusExams).NMPCsubmittal totheNRC,datedDecember23,1986,letternumberNMP1L0119(

Subject:

1986RFO-10Feedwater NozzleExamination Results).

NMPCsubmittal totheNRC,datedMarch21,1989,letternumberNMP1L0374(

Subject:

1988RFO-11Feedwater NozzleExamResults/NMPC PlansforFutureExaminations andEvaluation ofIdentified Indications).

7.NRCLetter,datedMay1,1989,(TACNo.72944)(

Subject:

SummaryofApril18,1989MeetingtoDiscussFeedwater Indications atNMP1).8.9.10.12.NMPCsubmittal totheNRC,datedMay5,1989,letternumberNMP1L0394(

Subject:

Feedwater NozzleIndication FractureMechanics Analysis).

NRCSafetyEvaluation ofUltrasonic TestIndications intheFeedwater InletNozzle"A"NearaNozzleSafeEnd(TAC72944),dated9/26/89.NMPCsubmittal totheNRC,datedJanuary11,1991,letternumberNMP1L0560(

Subject:

1988RFO-11Feedwater NozzleExamination Results).

NMPCInternalCorrespondence toUnit1Licensing FilefromN,A,Spagnoletti, datedMarch1,1993,FileCode003631GG(

Subject:

NotesofTeleconwithNRCRegarding Feedwater Nozzle"A"UTInspection).

NMPCsubmittal totheNRC,datedAugust25,1993,letternumberNMP1L0777(

Subject:

1993RFO-12Feedwater Nozzle"A"Examination Results).

I NMP1RPVFEEDWATER ANDCRDRLNOZZLEEXAMINATIONS 1995REFUELING OUTAGE(RFO-13)VIH.REFERENCCont'd13.NMPCNuclearEngineering ReportNo.NER-IM-006 "NineMilePointUnit1Feedwater NozzleFatigueEvaluation,"

datedMay1994,(Reference MPR-1484,Revision0).14.NMPCNuclearEngineering ReportNo.NER-IM-007 "NineMilePointUnit1ControlRodDriveReturnNozzleFatigueEvaluation,"

datedMay1994,(Reference MPR-1485, Revision0).15.NMPCsubmittal totheNRC,datedJune23,1994,letternumberNMP1L0829(

Subject:

AmendNUREG0619Commitment fromPTtoAutomated UTInspection).

16.NRCLetter,datedJanuary12,1995,(TACNo.M89792)(

Subject:

AmendNMPC'sNMP1NUREG0619Commitment utilizing theGERIS2000SystemfromAutomated UTInspection).

IX.APPENDICES APPENDIXAFEEDWATER NZZLEINSPECTION RULTAsstatedinNiagaraMohawk'sletterofDecember29,1980,theNineMilePointUnit1Feedwater andcontrolroddrivereturnlinenozzleswillbeperiodically reinspected atthefollowing intervals:

~Feedwater NozzleUT-everyotherrefueling outage,commencing withthe1981outage.~Feedwater NozzleVT-everyfourthrefueling outage,commencing withthe1981outage.~Feedwater andCRDNozzlePT-everysixthrefueling outageorevery90startup/shutdown cycles,commencing withthe1979refueling.

Duringthe1981refueling outage(RFO-8),aninservice UTexamination ofthefourfeedwater nozzleswasperformed byNESandalsobyGE.Anapparentchangefromthebaselineexamination wasobserved.

Furtherevaluation requiredremovalofthespargerfromthesoutheast nozzle.Basedontheresultsoftheadditional nondestructive examinations, NiagaraMohawkconcluded thattheUTindication wascausedbyageometric reflector andnotbyacrackinthenozzle.Anewfeedwater spargerwasinstalled inthesoutheast nozzle.Thedesignofthenewspargerwasthesameasthereplacement spargersinstalled duringthe1977refueling outage.Duringthe1983safe-endoutage,inservice inspections ofthefeedwater nozzleswerenotrequiredbyNUREG-0619 schedulecommitment.

However,thenozzleswereexaminedbyNESforinformation only.Anincreaseintheamplitude ofthesignalfromthegeometric reflector inthesoutheast nozzlewasnoted.Amorerigorousevaluation ofthisindication wasperformed duringthe1984refueling outageclearlyidentifying anddocumenting thatthisreflector isgeometric andhasexhibited nogrowthorchange.Duringthe1986refueling outage(RFO-10),

inservice UTexaminations ofthefourfeedwater nozzleswereperformed byNES.Nosignificant changesfromthepreviousexaminations wereidentified.

Duringthe1988refueling outage(RFO-11),

inservice UTexaminations ofthefourfeedwater nozzleswereperformed byNES.Theseexaminations identified approximately 25indications inthevicinityofthenozzletosafe-endweldofthenortheast nozzle"A"at45degrees.Althoughtheseindications mighthavebeencausedbyscratchmarksmadeduringspargerinstallation, weconservatively evaluated themascracks.NUREG0619,Section4.3.2.3states,"ifrecordable indications areinterpreted tobecracksinanynozzle,proceedwithspargerremoval,Fl'fthenozzleboreandnozzleblendradius,andrepair."Eighteenofthetwenty-five indications wereobservedat20to25%ofthedistanceamplitude correction e,

APPENDIXAFEEDWATER NZZLEINPETINRULTCnt'dcurve(DAC).However,theapplicable ASMECoderecording criteriais50%DAC.Therefore, theseindications werenot"recordable" anddidnotrequirefurtherevaluation.

Theremaining indications appearedtobetwoseparateflaws,onelocatedinthenozzleandonelocatedinthesafeendweld.Theindications appearedatapproximately 50%DAC.TheflawswereaxiallyorientedandtheirsizewellwithintheASMESectionXIacceptance criteria(a/t-4.7%

and7%versusallowable of11.02%and11.23%).Theexamination wasperformed usinga45degreeshearwavetransducer calibrated onanozzlemock-upwitha5%T-notchreflector.

TheCodepermitscalibration onnotchesupto10%T(Tisthenominalthickness ofthecalibration block).Consequently, theexamination sensitivity exceedstheCoderequiredsensitivity.

Ifa10%Tnotchhadbeenused,theseindications maynothavebeenrecordable perASMESectionXI.Considering thattheexamination wasperformed atahighersensitivity thanrequiredbyCode,thattheindications areatthethreshold oftherecording

criteria, andthattheindications willremainwithinallowable sizeforatleastthenexttwooperating cycles,NiagaraMohawkdetermined thatfurtherevaluation oftheseindications wasnotrequired.

Afracturemechanics evaluation ofthesetwoflawswasperformed.

Theresultsoftheanalysispredicted growthoftheflawsnottoexceed0,001inchesovera40-yearperiod.Therefore, theconclusion wasmadethattheflawswerenotsignificant andshouldnotaffectcontinued plantoperation.

Additionally, NiagaraMohawkcommitted toexaminefeedwater nozzle"A"duringthenextrefueling outage(1993).Duringthe1993refueling outage(RFO-12),

inservice UTexaminations offeedwater nozzle"A"(N4A)Zones1,2,3,and4wereperformed byGeneralElectricNuclearEnergy(GE-NE).Notetheindications identified in1988(RFO-12)werecontained inZone4ofN4A.Thesameultrasonic techniques wereemployedasusedduringthe1988refueling outage(RFO-11)examinations, otherthan,thecalibration standardwasmodifiedtoincludeCodeallowable 10%notchesaswellasthepreviously used5%notches.Theexaminations indicated noreportable indications.

TheZone4indications detectedinthe1988outagewereseenbutnotatrecordable levelsbasedoneitherthe5%or10%notchcalibrations.

ElectricPowerResearchInstitute (EPRI)sizingtechniques werethenattempted toseeifanadequatethrough-wall dimension couldbeattainedonthepreviously recordedindications.

Althoughabasesignalcouldbeseen,notipsignalswerenotedwitheithertheRelativeArrivalTimetechnique ortheAbsoluteArrivalTimetechnique.

Sincenotipcouldberesolved, thesourceofthesereflectors wasdetermined tobefromscratches orinsidediameter(ID)surfaceirregularities andnotfromIDcracking.

Theseinservice inspection resultshavebeenreviewedandapprovedbyaNiagaraMohawkLevelIIIexaminer.

APPENDIXAFEEDWATER NOZZLEINPECTINRULTSCont'dByletterdatedJune23,1994(NMP1L0820),NMPCinformedtheCommission, andprovidedtechnical basisfor,utilization oftheGEGERIS2000automated system(UT)forfutureexaminations inlieuofperforming aPT.ThisamendedourpriorNUREG0619commitment.

InaletterdatedJanuary12,1995,theNRCdetermined thatitwasacceptable forNMPCtoproceedwiththedescribed commitment changesandthatNMPCwouldbeadvisedofthefinalresultsoftheNRCreview.Duringthe1995refueling outage(RFO-13),

inservice examinations wereperformed onfour(4)feedwater andthecontrolroddrivereturnlinenozzles.TheUltrasonic Test(UT)examinations wereperformed byGE-NEandindicated noreportable indications wererecorded.

TheseUTexaminations utilizedtheGERIS2000automated systemandmanualUTpickups.Alloftheseexamination resultshavebeenreviewedandapprovedbyaNiagaraMohawkLevelIIIexaminer,

APPENDIXAFEEDWATER NOZZLEINSPECTION RESULTSN4ANOZZLE45DEGREENORTHEAST RESULTS19771NRI1979NRINRI1981GEOMETRIC REFLECTORS WELDREPAIREDCRACKINBRACKETPIN1983*GEOMETRIC REFLECTORS 1984~GEOMETRIC REFLECTORS GEOMETRIC REFLECTORS RESULTSGEOMETRIC

&NON-GEOMETRIC REFLECTORS 1993FO-12NRINRI1995FO-13NRIAMENDEDMETHODPERFORMED UTNOTES:NOTREQUIREDBYNUREG-0619.

PERFORMED FORINFORMATION ONLY.THE1983SAFE-ENDREPLACEMENT OUTAGEISNOTCONSIDERED AREFUELING OUTAGEBYNIAGARAMOHAWK.NRIUTPTVT(I)NOREPORTABLE INDICATION ULTRASONIC TESTINGDYEPENETRANT TESTINGVISUALTESTINGNOREPORTABLE INDICATIONS EITHERBEFOREORAFTERSPARGERREPLACEMENT 10

APPENDIXAFEEDWATER NOZZLEINSPECTION RESULTSN4BNOZZLE135DEGREOUTHEASTRESULTS1977119791981219831984~UTVTNRINRINRI1-1/2"LONGX314"5-1I2"LONGX0.8"DISPOSITIONED GEOMETRIC DEEPGEOMETRIC DEEPAMPLITUDE ASGEOMETRIC REFLECTORS INCREASEOF309o8INDICATIONS DISPOSITIONED ASMINORSURFACEIRREGULARITIES NRIRESULTSVT1988FO-11GEOMETRIC REFLECTORS 1993FO-12NRI1995FO-13NRIAMENDEDMETHODPERFORMED UTOTES:NOTREQUIREDBYNUREG4619.

PERFORMED FORINFORMATION ONLY.THE1983SAFE-ENDREPLACEMENT OUTAGEISNOTCONSIDERED AREFUELING OUTAGEBYNIAGARAMOHAWK.NRIUTPTVT(1)(2)NOREPORTABLE INDICATION ULTRASONIC TESTINGDYEPENETRANT TESTINGVISUALTESTINGNOREPORTABLE INDICATIONS EITHERBEFOREORAFTERSPARGERREPLACEMENT SPARGERPULLEDFOREVALUATION OFINDICATIONS.

NEWSPARGERINSTALLED.

11

APPENDIXAFEEDWATER NOZZLEINSPECTION RESULTSN4CNOZZLE225DEGREESSOUTHWEST RESULTS19771NRINRI1979NRINRI1981GEOMETRIC REFLECTORS NRI19834GEOMETRIC REFLECTORS 19844ACCEPTABLE INCLUSION 1986FO-10GEOMETRIC REFLECTORS UTGEOMETRIC REFLECTORS

&ACCEPTABLE NON-GEOMETRIC REFLECTORS 1993RFO-12NRI1995FO-13NRIAMENDEDMETHODPERFORMED UTNOTES:NOTREQUIREDBYNUREG-0619.

PERFORMED FORINFORMATION ONLY.THE1983SAFE-ENDREPLACEMENT OUTAGEISNOTCONSIDERED AREFUELING OUTAGEBYNIAGARAMOHAWK.NRIUTPTVT(I)NOREPORTABLE INDICATION ULTRASONIC TESTINGDYEPENETRANT TESTINGVISUALTESTINGNOREPORTABLE INDICATIONS AFTERCOMPLETION OFREPAIRACTIVITIES ANDREPLACEMENT OFSPARGER.12 I

APPENDIXAFEEDWATER NOZZLEINSPECTION RESULTSN4DNOZZLE315DEGREESNORTHWEST

~~RESULTSPT19771NRINRINRI1979NRI1981GEOMETRIC REFLECI'ORSNRI1983*TWOINDICATIONS NOTGEOMETRIC 25%FSH1984+NRI1986FO-10GEOMETRIC REFLECTORS RESULTSUTVT1988RFO-11GEOMETRIC REFLECTORS NRI1993FO-12NRI1995FO-13NRIAMENDEDMETHODPERFORMED UTNOTES:NOTREQUIREDBYNUREG4619.

PERFORMED FORINFORMATION ONLY.THE1983SAFE-ENDREPLACEMENT OUTAGEISNOTCONSIDERED AREFUELING OUTAGEBYNIAGARAMOHAWK.NRIUTPTVT(1)NOREPORTABLE INDICATION ULTRASONIC TESTINGDYEPENETRANT TESTINGVISUALTESTINGNOREPORTABLE INDICATIONS AFTERCOMPLETION OFREPAIRACTIVITIES ANDREPLACEMENT OFSPARGER.13

APPENDIXACONTROLRODDRIVERETURNLINENOZZLEINSPECTION RTN9NOZZLE44.1-WD417/01S-IR RESULTS19771197919811983~19848'986 FO-10NRIRESULTS1988FO-111993RFO-121995FO-13NRIAMENDEDMETHODPERFORMED UTNOTES:NOTREQUIREDBYNUREG-0619.

PERFORMED FORINFORMATION ONLY.THE1983SAFE-ENDREPLACEMENT OUTAGEISNOTCONSIDERED AREFUELING OUTAGEBYNIAGARAMOHAWK.NRIUTPTVT0)NOREPORTABLE INDICATION ULTRASONIC TESTINGDYEPENETRANT TESTINGVISUALTESTINGNOREPORTABLE INDICATIONS EITHERBEFOREORAFTERSPARGERREPLACEMENT 14

~~4APP~~IX3MODIFICATION ORSYSTEMCHANGESAFFECTFEEDATERFLWORTEMPERAE1997.Feedwater nozzlecladdingremovedandspargersreplacedwithimproveddesign.~179ReactorWaterCleanupreturnlinereroutedtothefeedwater lineinaccordance withSection4.2ofNUREG-0619.

1981Replacedsoutheast spargerafterevaluation ofUTindications.

1983Thefeedwater lowflowcontrolvalveswerereplacedwithnewvalvesdesignedtoimprovecontrolatlowflowconditions.

Inaddition, asix-inchrecirculation linewasinstalled toprovideimprovedflowcontrolofthefeedwater system.Thesemodifications werepreviously described inourletterdated9/8/81.19914InresponsetoNUREG0737,ActionItemII.D.1,instrument andcontrolequipment wereinstalled toprovideahighreactorleveltripofthemotor-driven feedwater pumps.Inaddition, theHPCIcontrolsystemwasmodifiedtoaddannunciator alarmsforlossofHPCIfailuresignalinstandbymode.1998iThefollowing changesweremadetoimprovethereliability ofthefeedwater system:1.Modifiedhighleveltripcircuitsealinlogic.2.Modifiedmainflowvalvelockupcircuitstowithstand momentary powerinterruptions.

3.Modifiedlogictoclose6-inchrecirculation valveonpumpstartsignalforrunoutprotection.

4.ModifiedlogictocloselowflowcontrolvalvesonHPCIinitiation.

199Noadditional modifications orsystemchangesthataffectfeedwater flowortemperature.

~193Turbinedrivenfeedwater pumpflowcontrolvalveswerereplacedbyasingleflowcontrolvalve;thischangehadnoaffectonfeedwater flowortemperature.

~195Noadditional modifications orsystemchangesthataffectfeedwater flowortemperature.

15

APPENDIXCDESCRIPTION OFTRANIEXAMINATI NPRCEDA.IIXILPPWM~TheNESfeedwater nozzleUTexamination procedure wasfirstusedatNineMilePointUnit1in1981.Thisprocedure dividedthenozzleinnerradiusandboresurfacesintotwozones,NESZone1examinations areperformed fromthereactorvesselshell;NESZone2examinations areperformed fromthenozzlebarrel.NESZone1andZone2examinations overlapattheinsideradiussurfaceofthenozzle.Examinations performed fromthereactorvesselshellareperformed byattaching aspecially designedlucitewedge,whichconformstothereactorvesseloutsideradius,toanultrasonic transducer suchthatthelongitudinal beamangleisfixed.Examinations performed fromthenozzlebarrelareperformed usingcompoundanglebeamshearwavetechniques.

Inthiscase,anumberofspecially designedfixedcompoundanglelucitewedgeswhichconformtotheoutsideradiusofthenozzlebarrelareused.In1988,additional scansandscanningangleswereusedonthesafe-endbore,nozzlebore,andtheinnerradiustoensureoptimalinterrogation oftherequiredvolumes.Recording criteriawasupdatedformoreuniformity whencomparing datafromeachoutage.Anewtemplatewasdesignedandbuilttofacilitate shell-side exams.B.~GEPC.URBTheGEfeedwater nozzleUTexamination procedure wasusedforthe1977baselineandthe1979inservice inspections atNineMilePointUnit1.Thisprocedure dividesthenozzleinnerradiusandboresurfacesintothreezones.TheGEZone1examination isperformed byattaching anultrasonic transducer toaspecially designedlucitewedge,whichconformstothereactorvesseloutsideradius,suchthatthelongitudinal beamangleandthecircumferential beamanglearefixed.TheGEZone2examination isperformed byattaching anultrasonic transducer toaspecially designedlucitewedge,whichconformstotheouterdiameterblendradiusofthenozzle,suchthatthelongitudinal beamangleandthecircumferential beamanglearefixed.TheGEZone3examination isperformed byattaching anultrasonic transducer toaspecially designedlucitewedge,whichconformstotheoutsideradiusofthenozzlebarrel,suchthatthecircumferential beamangleisfixed.16

tAPPENDIXCDESCRIPTION OFULTRANICEXAMINATION PROCEDURC.NMPCPROCEDURE NiagaraMohawkNDEProcedure (No.NDEP-UT-6.07) wasusedtoUTexaminefeedwater nozzle"A"(N4A)Zones1,2,3,and4duringthe1993refueling outage(RFO-12).

Thisprocedure utilizedmanualtechniques andequipment whicharesimilarandequivalent tothoseusedbyNESduringthe1988refueling outage(RFO-11).Theultrasonic techniques employedarethesameasthoseusedfortheRFO-11examinations, otherthan,thecalibration standardwasmodifiedtoincludeCodeallowable 10%notchesaswellasthepreviously used5%notchesforthesafe-endboreexamination.

Theseexaminations wereperformed byGeneralElectricNuclearEnergy(GE-NE)personnel.

D.DESCRIPTION OFGE-NEGERIS-2000 AUTOMATED VTINSPECTINYTEMF-13TheGERIS-2000 UTImagingSystemisanautomated ultrasonic dataacquisition andimagingsystem.Automated scannersinterfaced totheGERIS-2000, movedUTtransducers radiallyandcircumferentially aroundtheoutsidesurfaceofthenozzleandadjacentsurfacesofthesafe-endandreactorpressurevessel.UTdatawascollected andstoredindigitalformat.ThecompleteRFwaveformwasdigitized andrecordedonopticaldisksforanalysis, TheGERIS-2000 UTsubsystem isamultiplexed logarithmic UTflawdetection instrument.

Foreachchannel,thecompleteRFA-scanwasdigitized andstoredonopticaldisks.ThesystemstorestheRFsignalinlogarithmic formatthathasaninstantaneous dynamicrangethatisgreaterthan85dB.Thelogarithmic UTsystemallowstherecording ofthepeaksoflowandhighamplitude UTsignalsatthesametimewithoutclippingUTsignals,suchaswouldoccurwithlinearsystemsthathaveaninstantaneous dynamicrangegenerally lessthan45dB.TheanalysisoftheGERIS-2000 datautilizedadvancedinteractive colorgraphicstoevaluateandassistincharacterizing indications fromservice,fabrication andgeometric relatedUTreflectors.

Coordinated A-,B-,C-,volumetric side-view-,

volumetric end-view-,

and3D-scansareprovidedonahighresolution (1280by1024pixels)colordisplay.Severalchannelsmaybedisplayed atonetimetocorrelate indications fromdifferent channels.

Thesegraphicdisplayshaveanadjustable colorscalethatprovidesthebestresolution offlawdetection andcharacterization downtothematerialnoise.NMPCsubmittal ofJune23,1994tReference

¹13]includedEnclosure 1,SectionII,"Ultrasonic Inspection Techniques",

whichprovidedadescription oftheGERISUTtechniques, UTinstrumentation andscanningequipment indetail.17

tAPPENDIXCDESCRIPTION OFULTRANICEXAMINATI NPROCEDURES Cont'dD.DCRIPTIONFE-NEGERT-2000AUTMATEDVTINPECTIONSYSTEMCont'dAmplitude-based recording andreporting criteriaisnotusedwiththeGERIS-2000 fornozzleinnerradiusandboreexaminations.

AllUTdataisrecordedandevaluated.

AnyUTdatathathassignal-to-noise ratiosofgreaterthan2-to-l,hasecho-dynamic characteristics ofcrackingandcanbeconfirmed from2directions oraccompanied bytip-diffracted signalsarecalledcracks.TheGERIS-2000 systemiscapableofdetecting andsizingaxialflaws0.250inchesorlessindepthinfeedwater nozzleinnerradiusandboreregions.Thecapability oftheGERIS-2000 systemfordefectdetection andsizingwasdemonstrated andincludedinNMPCsubmittal June23,1994[Reference

¹13]inEnclosure 1,SectionIII,"Ultrasonic Technique Qualification Plan",whichprovidedadetaileddescription oftheEDMnotchesandfatigue-crack implantsthatareusedtodemonstrate thecapability oftheGERIS-2000 system.Whenobstructions limitedautomated scanningcoverage, supplemental manualexaminations wereperformed.

Inbothcases,fullIDcoveragewasobtainedfromatleastonedirection.

Whenautomated scanningcannotbeperformed frombothdirections, manualtechniques utilizing thesametechniques astheautomated examinations wereused.TheentireIDsurfaceofzones1through5(seeFigure1below)wereexaminedforaxialflawsfromatleast1direction witheitherautomated ormanualtechniques.

Areasexaminedwerefullydocumented intheinspection results.ThemethodusedtoensurethattheNMP1feedwater nozzlesareexaminedwithequivalent techniques isthroughtheuseofmodeling.

ThemodelingusedwaswheretheUTbeampathsarepredicted usingraytracingalgorithms withpredetermined beamangleparameters.

Thebeampathsareusedtodetermine theincidentanglesofthebeamontheIDsurfaces.

TheincidentanglesoftheUTbeamontheIDsurfacesusedontheNMP1feedwater nozzlewerecomparable totheGEqualification mockups.Multipleangle-beam transducers designedfrom"asbuilt"andfabrication wereusedtofullyexaminezones1through5.18 r

~N4'APPENDIXCDESCRIPTION OFULTRASNICEXAMINATION PROCEDURES Cont'dVESSELINOZZLE)SAFEEND~BB,/l4B44,4BlFigure1-NouleExamination Zones19 F