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{{#Wiki_filter: | {{#Wiki_filter:NIAGARAMOHAWKPOWERCORPORATION NINEMILEPOINTUNIT1NUCLEARPOWERSTATIONREPORTOFREACTORPRESSUREVESSELFEEDWATERANDCONTROLRODDMVERETURNLINENOZZLEEXAMINATIONS performed forNUREG0619BWRFEEDWATER NOZZLEANDCONTROLRODDRIVERETURNLINENOZZLECRACKINGattheculmination ofREFUELING OUTAGENO.13whichendedonApril4,1995Thisdocumentcompleted SEPTEMBER 29,19959510100318 951003PDRADOCK05000220,,P...,PDR,, | ||
l~Q | 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: | ||
I | 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. | |||
I | 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~ | 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:== | ==Subject:== | ||
Inservice Inspections ofFeedwater NozzlesandSpargersPerformed Duringthe1981Refueling Outage).3.4,5.6.NESLetter,T.J.KochtoT.W.Roman,datedMarch4,1983( | |||
==Subject:== | ==Subject:== | ||
February, | : February, 1983Feedwater NozzleInnerRadiusExams).NESLetter,W.R.DownstoT.W.Roman,datedJune27,1984( | ||
==Subject:== | ==Subject:== | ||
April, | |||
April,1984Feedwater NozzleInnerRadiusExams).NMPCsubmittal totheNRC,datedDecember23,1986,letternumberNMP1L0119( | |||
==Subject:== | ==Subject:== | ||
1986RFO- | |||
1986RFO-10Feedwater NozzleExamination Results). | |||
NMPCsubmittal totheNRC,datedMarch21,1989,letternumberNMP1L0374( | |||
==Subject:== | ==Subject:== | ||
1988RFO- | |||
1988RFO-11Feedwater NozzleExamResults/NMPC PlansforFutureExaminations andEvaluation ofIdentified Indications). | |||
7.NRCLetter,datedMay1,1989,(TACNo.72944)( | |||
==Subject:== | ==Subject:== | ||
SummaryofApril18, | |||
SummaryofApril18,1989MeetingtoDiscussFeedwater Indications atNMP1).8.9.10.12.NMPCsubmittal totheNRC,datedMay5,1989,letternumberNMP1L0394( | |||
==Subject:== | ==Subject:== | ||
Feedwater NozzleIndication FractureMechanics Analysis). | |||
NRCSafetyEvaluation ofUltrasonic TestIndications intheFeedwater InletNozzle"A"NearaNozzleSafeEnd(TAC72944),dated9/26/89.NMPCsubmittal totheNRC,datedJanuary11,1991,letternumberNMP1L0560( | |||
==Subject:== | ==Subject:== | ||
1988RFO- | |||
1988RFO-11Feedwater NozzleExamination Results). | |||
NMPCInternalCorrespondence toUnit1Licensing FilefromN,A,Spagnoletti, datedMarch1,1993,FileCode003631GG( | |||
==Subject:== | ==Subject:== | ||
NotesofTeleconwithNRCRegarding Feedwater Nozzle"A"UTInspection). | |||
NMPCsubmittal totheNRC,datedAugust25,1993,letternumberNMP1L0777( | |||
==Subject:== | ==Subject:== | ||
1993RFO- | |||
I | 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:== | ==Subject:== | ||
AmendNUREG0619Commitment fromPTtoAutomated UTInspection). | |||
16.NRCLetter,datedJanuary12,1995,(TACNo.M89792)( | |||
==Subject:== | ==Subject:== | ||
IX. | 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~~ | ~~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. | |||
~N4' | 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}} |
Revision as of 02:27, 29 June 2018
ML18040A167 | |
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Site: | Nine Mile Point ![]() |
Issue date: | 09/29/1995 |
From: | NIAGARA MOHAWK POWER CORP. |
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Text
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