ML102110459

Response to Request for Additional Information, Application for Technical Specifications Change Risk-Informed Justification for Relocation of Specific Surveillance Frequency Requirements to Licensee Controlled Program

ML102110459
Person / Time
Site:	Three Mile Island
Issue date:	07/29/2010
From:	David Helker Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TMI-10-072
Download: ML102110459 (15)

Text

Exe lonNu clea r 200 ExelonWay Kennett Square.P A 193 48 TMI-10-072July29,2010 w ww.exeloncorp.co m Exelon.Nuclear10CFR50.90 U.S.Nuclear Regulatory Commission A TIN: DocumentControlDesk Washington,D.C.20555-0001ThreeMileIsland NuclearStation,Unit1RenewedFacility OperatingLicenseNo.DPR-50 NRC Docket No.50-289

References:

ResponsetoRequestforAdditionalInformation

,Applicationfor Technical Specificat ions Change Regarding Risk-Informed JustificationfortheRelocationofSpecific Surveillance FrequencyReqUirementstoaLicenseeControlledProgram(Adoptionof TSTF-425 , Rev ision 3)1.LetterfromPamelaB.Cowan

,ExelonGeneration Company , LLC ,toU.S.Nuclear Regulatory Commission,"ApplicationforTechnical SpecificationsChangeRegarding Risk-Informed JustificationfortheRelocationofSpec ific Surveillance Frequency RequirementstoaLicenseeControlledProgram (Adopt ion of TSTF-425,Revision3),"datedMarch24

, 2010.2.LetterfromPeterBamford

,U.S.Nuclear Regulatory Commission

, toMichaelJ.Pac ilio,ExelonNuclear,"ThreeMileIsland NuclearStationRequestforAdditional InformationRegardingLicense Amendment RequesttoAdoptTSTF-425,Relocationof Surveillance FrequenciestoaLicenseeControlledProgram(TACNo.ME3587),"datedJuly2,2010.InReference1

,ExelonGenerationCompany,LLC(Exelon)submittedarequestforan amendmenttothe Technical Specifications (TS),AppendixAofRenewedFacility OperatingLicenseNo.DPR-50forThreeMileIsland Nuclear Station , Un it1(TM IUnit1).The proposed amendmentwouldmodifyTMIUnit1TSbyrelocatingselectedSurveillance Requirement frequenciestoalicensee-controlledprogram.TheNRCreviewedthelicense amendmentrequestandident ifiedtheneedforadditional informationinordertocompletetheir evaluation of the amendmentrequest.OnJune17

, 2010 , draft questionsweresenttoExelontoensurethatthequest ions were understandable

,theregulatorybasisforthe questionswasclear,andto determineifthe informat ion was previouslydocketed.OnJune23,2010

, a teleconference washeldbetweentheNRCandExelontofurtherd iscusstheadditionalinformationrequestedbytheNRC.InReference2

,theNRCformallyissuedtherequestforadditionalinformation

.Attachment1tothisletterprovidesa restatementofthe questionsalongwithExelon

's responses.Inaddition, TSTF-425 ,Revision3,"RelocateSurveillance FrequenciestoLicenseeControl RITSTF[Risk-Informed Technical SpecificationsTaskForce]Initiative5b

,"datedMarch18

,2009,providedanoptionalinserttoexistingTSBasestofacilitateadoptionofthe TSTF traveler.The TSTF-425TSBasesinsertstatesasfollows:

ResponsetoRequestforAddit ional InformationLAR-Adoptionof TSTF-425,Revision3 Docket No.50-289July29 , 2010Page2"The Surveillance Frequencyisbasedon operating experience, equipment reliability

, andplantriskandis controlled under the Surveillance FrequencyControlProgram." Recently several licensees SUbmitting license amendmentrequests(LARs)foradoptionof TSTF-425haveidentifiedaneedtodeviatefromthis statement becauseitonlyappliesto Surveillance Frequenciesthathavebeenchanged i n accordancewiththe Surveillance FrequencyControlProgram(SFCP)anddoesnotapplyto Surveillance FrequenciesthatarerelocatedtotheSFCPbutnotchanged.For Surveillance FrequenciesrelocatedtotheSFCPbutnotchanged

, the existingTSBases descriptionprovidesavalid descriptionofthebasesfor the unchanged Surveillance Frequencies

.Therefore , upon implementationofthe proposed change , where appropriate

,theexistingTSBasesinformation describingthebasesforthe Surveillance FrequencieswillberelocatedtotheSFCP.Thiswillensurethatthe information describingthebasesfor unchanged Surveillance Frequenciesismaintained.Also

,relativetotheBasesinsert,Exelonproposestoreplacethe TSTF-425 Bases insert specifiedabovewitharevisedinsertthatreads "The Surveillance Frequenciesarecontrolledunde r the Surveillance FrequencyControlProgram,"asindicatedon revised proposed TS/Basespagesprovidedin Attachment 2.Exelonhas concludedthatthe informationprovidedinthisresponsedoesnotimpactthe conclusions provtdedintheoriginal submittal (Reference 1).Thisresponsetotherequestfor additional information contains no regulatory comm itments.Ifyouhaveany questionsorrequire additionalinformation,please contactGlennStewartat 610-765-5529

.Ideclareunderpenaltyofperjurythattheforegoingistrueandcorrect.Executedonthe29 t hdayofJuly2010.

Respectfully

,DavidP.Helker Manager , Licensing&Regulatory Affairs Exelon GenerationCompany,LLC Attachment1:ResponsetoRequestforAdditionalInformation Attachment2:RevisedProposed Technical Specifications/Bases Pages cc: Regional Administrator-NRCRegionINRCSeniorResident Inspector-TMIUnit1NRCProjectManager,NRR-TMIUnit1 Director ,BureauofRadiationProtection-PA Department of Environmental ResourcesChairman,Boardof County CommissionersofDauphin County Chairman ,Boardof Supervisors of Londonderry Township w/attachments ATTACHMENT 1 License Amendment Request Three Mile Island Nuclear Station, Unit 1 DocketNo.50-289 Application for Technical Specification Change RegardingInformed Justification for the Relocation of Specific Surveillance Frequency Requirements to a Licensee Controlled Program (Adoption of TSTF-425, Revision 3)Response to Request for Additional Information DocketNo.50-289 Attachment 1Page1of9 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION APPLICATION FOR TECHNICAL SPECIFICATION CHANGE REGARDINGINFORMED JUSTIFICATIONFORTHE RELOCATION OF SPECIFIC SURVEILLANCE FREQUENCY REQUIREMENTSTOA LICENSEE CONTROLLED PROGRAM (ADOPTION OF TSTF-425,REVISION3)

In Reference 1 , Exelon GenerationCompany,LLC(Exelon) submittedarequestforan amendmenttotheTechnical Specifications(TS),AppendixAofRenewedFacility OperatingLicenseNo.DPR-50forThreeMileIsland NuclearStation,Unit1(TMIUnit1).The proposed amendmentwouldmodifyTMIUnit1TSbyrelocatingselected Surveillance Requirement frequenciestoa licensee-controlled program.TheNRCreviewedthelicense amendmentrequestandidentifiedtheneedfor additional informationinorderto complete their evaluation of the amendmentrequest.OnJune17,2010,draft questionsweresenttoExelontoensurethat the questions were understandable,theregulatorybasisforthe questionswasclear,andto determineifthe information was previously docketed.OnJune23,2010,a teleconference washeldbetweentheNRCandExelontofurtherdiscusstheadditional informationrequestedbytheNRC.InReference2

,theNRC formallyissuedtherequestforadditional information (RAI).The questionsarerestatedbelowalongwithExelon'sresponses.TheLARstatesthatthe changes presented are consistent with TSTF-425andalso includes a discussionofthe differencesinthe applicat ionthatresultprimarilyfromthecustomTMI-1TSs as comparedtotheSTSs presentedinTSTF-425 and NUREG-1430.TheLAR, Attachment 4,"TSTF-425 (NUREG-1430) vs.TMIUnit1 Cross-Reference,"isprovidedtoaidinthe determination of consistencyofthe surveillancesproposedforrelocationas comparedto425.Inordertoverifythatthe surveillancesproposedforrelocationare consistentwith425astheLARasserts,theNRCstaffrequeststhatthelicenseeprovide corresponding425cross referencesforthefollowing surveillance frequencies proposedforrelocation:Table 4.1-1,"Instrument Surveillance Requirements," Channel DescriptionNos.11,15,17,1ge,19f,45,and46.RESPONSE The corresponding TSTF-425 cross-referencesforthespecifiedTMITSTable4.1-1 instrument channel descriptionsareprovidedinthetablebelow.TMITS Table 4.1-1 TSTF-425/NUREG-1430 Comments Item Description Equivalent 11"ReactorCoolantPressure

-SR3.3.1.1STSTable3.3.1-1,Item5 Temperature Comparator"SR3.3.1.4SR3.3.1.5 15"HighPressureInjectionAnalogSR3.3.5.1STSTable3.3.5-1,Items1

&2 Channels"SR3.3.5.2SR3.3.5.3 17"LowPressureInjectionAnalogSR3.3.5.1STSTable3.3.5-1,Items1

&2 Channels"SR3.3.5.2SR3.3.5.3 ResponsetoRequestforAdditional InformationLAR-Adoptionof TSTF-425, Revis ion 3DocketNo.50-289 Attachment 1Page2of9TMITSTable4.1-1 TSTF-425/NUREG-1430 Comments Item Description Equivalent tse"ReactorBldg.PurgeLineHighSR3.3.15.1Radiation(AH-V-1A1D)" SR 3.3.15.2SR3.3.15.3 191"Linebreakisolationsignal(ICCWSR3.3.5.1Linebreakisolationisa&NSCCW)"SR3.3.5.2diversemethodforReactor SR 3.3.5.3BuildingIsolation.Thisisa TMI-specific s ignalwhichis redundanttoasignalonReactorBuildinghigh pressureandaccompl ishesthesamefunctionasSTSTable3.3.5-1,Item3 45"Lossof FeedwaterReactorTrip"SR3.3.1.1STSTable3.3.1-1,Item10 SR 3.3.1.4SR3.3.1.546"TurbineTrip/ReactorTrip "SR3.3.1.1STSTable3.3.1-1,Item9 SR 3.3.1.4SR3.3.1.5WithreferencetotheLAR, Attachment2,Table2-1,eachofthefind ingsinthe following tableidentifiedanissueorgapthat, individually,mightnot significantlyimpacttheresultsfroma surveillancetestinterval(STI)riskevaluation performedviatheNEI04-10 methodology

, but,whentaken cumulatively,couldprovesignificant.TheNRCstaff'sconcern associated witheachis highlightedinitalics.Please addresswhether,whentaken cumulatively,theireffectscouldprove significanttotherisk evaluationforanSTITSchangeand,ifnot

,whynot.RESPONSE SubsequenttotheLARsubmittal,severalofthegapsidentifiedinthisRAIwere addressed andresolved.Thefollowinggapshavebeenresolvedas describedinthetablebelow:*IE-A5-01*IE-A7-01*LE-E4-01 Additionally

,responsesforthefollowingthreegapsareprovidedinthetablebelow:*IE-A4a-01*QU-D5-01*SC-C2-01Basedonthe discussionsprovidedinthetable,thesegapsarestill consideredtonotimpacttheresultsofanSTIevaluation.

ResponsetoRequestforAdditional InformationLAR-Adopt ion of TSTF-425 ,Revision3DocketNo.50-289 Attachment 1Page3of9 A sensitivity calculation was performedtoaddressLE-C8a-01.The sensitivityshowsthatthereisno impactonthebasemodelresults

,butadditional sensitivitieswillbe performed,i f necessary,tosupportspecificSTI evaluations.

Also ,forQU-F5-01

,thetechnical adequacy associatedwiththisgapis accountedforintheNEI 10process(see discussionintable).ThisleavesonlygapIE-A6-01asnot addressed; however ,thisisnotexpectedtohaveanimpactas describedinthetablebelow.Sincethreeofthegaps identifiedintheRAIareresolved,therearesixopengapsrema ining;fourofthesehavenoimpact,andtwowillbe addressed by sensitivitiesrequiredbytheNEI 10 methodology.Asaresult,thereisno cumulativeimpactoftheseopengaps.

ResponsetoRequestforAdditionalInformationLAR-Adoptionof TSTF-425,Revision3DocketNo.50-289 Attachment 1Page4of9 Finding Issue/Gap Status of Issue/Gap IE-A4a-01"Thepotentialforcommoncausefailures[CCFs]wasThetextofthe commentprovidedforIE-A4a-01intheincludedinexaminationofpotentialinitiatingeventsLARwas misleading.Infact,the examination forresultingfromthe systematicevaluationforpotentialpotentialinitiatingeventsdidinclude common causeinitiatingevents." As recommended per[Regulatoryfailuresfromroutinesystem alignmentsthatcould Guide]RG1.200,Rev.

2, for Supporting Requirementresultfrom preventive or corrective maintenance.(SR)IE-A6 (Capability Category[(CC)]-II),thisTherefore,theitalicizeditemisnotanissueinthe examination should also includeCCFsfromroutine performanceofSTI evaluations.

system alignments that could result from preventive and corrective maintenance.IE-A5-01"No documentationwasfoundof incorporating: (a)SubsequenttotheLARsubmittal,anewreviewwaseventsthathaveoccurredatconditionsotherthanat-performed and documentedforeventsmeetingeitherpoweroperation(Le.,during low-powerorshutdown(a)or(b)inSRIE-A?Thereviewcoveredevents conditions),andforwhichitis determinedthatthe from January1,1990to December 31,2009.Noneweventcouldalsooccurduring at-poweroperation;(b)initiatorswereidentifiedfromthisreview.

Therefore,eventsresultingina controlledshutdownthatthisgapisresolved.includesascrampriortoreaching low-powerconditions,unlessitis determinedthataneventisnot applicable to at-power operation."SRIE-A 7 requiresthat,evenifnot documented,theseeventshavetobe incorporated.

ResponsetoRequestforAdditionalInformationLAR-Adoptionof TSTF-425,Revision3DocketNo.50-289 Attachment 1Page5of9 Finding Issue/Gap Status of Issue/GapIE-A6-01"No documentationwasfoundofinterviewswithplant SubsequenttotheLARsubmittal,anewreviewwas and personnel (e.g., operations

, maintenance, performed and documented for precursor events.The IE-A7-01 engineering,safetyanalysis)todetermineifpotentialreviewcoveredeventsfrom January1,1990toinitiatingeventshavebeen overlooked...No December31,2009.Nonewinitiatorswereidentified documentationofthereviewof plant-specificfromthisreview

.Therefore ,gapIE-A7-01isresolved.operatingexperienceforinitiatingeventprecursorswasfoundinthe

[probabilistic risk assessment]

PRARecentinterviewswithplant personnel (IE-A6-01) are notebooks."Evenif not documented,CC-IIforbothstilloutstanding.Basedon completion and oftheseSRs requiresthatthe interviews(SRIE-AB documentationofthereviewof plant-specific operating[CC-II],withfinding IE-A6-01)and reviews(SRIE-A9experienceforprecursors,previous (undocumented)[CC-II],withfinding IE-A7-01)havebeen conducted.plantpersonnel interviews, and otherinitiatingevent identificationmethodsusedfortheTMIPRA

, thelikelihoodofplantpersonnel interviews identifyingadditionalpotential plant-specificinitiatingeventsis low.SC-C2-01 SR SC-C2 requiresthat,even if not documented (orForsuccesscriteriathatwere developedforthePRA, else stillinthe process of being documented), generallyMAAP4isusedinsteadofusingdesign computercode"limitations or potential basis success criteria.Theoverallconclusionfrom conservatisms"havetobe addressed.theEPRIMAAP Thermal-Hydraulic QualificationStudieswasthatMAAPhadawiderangeof applicability;however,afew limitationswereidentified.ThecurrentpositiononMAAPcode limitationscanbefoundontheMAAP4website.Thesign ificantlimitationofMAAPforPWRsisLargeLOCA behaviorpriortoreflood.TheTMIPRAusesdesignbasiscriteriaforLargeLOCAs,sothis limitationofMAAP4hasbeenaddressed.

ResponsetoRequestforAdditional Information LAR-Adoptionof TSTF-425,Revision3 Docket No.50-289 Attachment 1Page6of9 Finding Issue/Gap Status of Issue/Gap QU-D5-01"SomeSSCs[structures,systems,and components]

Significant contributorstoinitiatingeventswerethatare significant contributorstoinitiatingevents,butidentifiedthroughareviewofsupportsysteminitiatingnottomitigation,arenotexplicitlyidentifiedintheeventcutsets,buttheindividual contributors and documentation of significant contributors."CC-IIforcutsetswereomittedfromthe quantification notebook.SRQU-D6, againstwhichthisfinding is cited ,Itshouldbenotedthatinitiatingeventfaulttreesarerequiresthat significant contributorstocoredamage re-quantifiedforanyapplication affecting the frequency, including initiating events, and SSCs and components or configurationsrepresentedbythese operator actions that contribute to initiating eventfaulttrees.frequencies,beidentified.While"not explicitly identified"inthe documentation,werethese significant contributorstoinitiatingevents actually identified but just omittedfromthe documentation?

Iftheywerenotidentified, howweretheyknowntobe significant andtowhat extent?QU-F5-01"[O]therthanthe[largeearlyreleasefrequency]LERFLERF truncationistheonly identifiedlimitationtothetruncationlimitation,noevaluationsof limitationsTMIPRAmodelfor applications.

Additional limitations were presented...,[including]

limitationsofthemodelmayexist(e.g.,STI componentsnotmodeledintheastheymayapplyto applications." As implied by SRPRA),buttheNEI04-10 process(Step8)requiresanQU-F5,these limitations needtohavebeen assessment of whethertheSTIchangecanbe addressed.

adequately characterizedbythePRA.

ResponsetoRequestforAdditionalInformationLAR-AdoptionofTSTF-425,Revision3DocketNo.50-289 Attachment 1Page7of9 Finding Issue/Gap Status of Issue/Gap LE-C8a-01"TheReactorBuildingfancoolersare undersized atInresponsetothisRAI,a sensitivity analysis wasTMIandhavealittletonoimpacton containment performedtodeterminetheimpactonthebase[CNMT]pressureand temperaturewithrespectto(average)PRAmodelassumingtheReactorBuilding early containment failure."SRLE-C9(CC-II)requiresfancoolerswerenotavailablefollowingcoredamage.

justification for any credittakenfor equipmentTherewasnochangetotheLERFresults(Le., survivability under adverse environmental conditionsidenticallargeearlyreleasecutsetsand frequency).

Itsuchthat,even ifthefancoolerswere assumedtobeisexpectedthatthisconclusionwillbethesameforfailed,therewouldbe"littletono impact" on CNMT most applications.However,thereisstillapotential pressure andtemperaturewith respecttoearly CNMTthatthe assumptionfortheReactorBuildingfan failure.coolerssurvivingadverse environmental conditionsmayimpactaspecificSTI evaluation being performed.Toaddressthispotential,the commentforthisgapintheLARstatesthatitwillbeevaluatedviaa sensitivityanalysisperNEt04-10,if applicabletotheSTI.LE-E4-01"Thelevel2resultswiththeflagfileareexpectedto SubsequenttotheLARsubmittal,thisF&O/gapwas be conservative.Whenthecutsetswerereviewed,itresolved.Atestwas performedthatwas similartothat was determinedthatthereappearstobe non-minimaldonebythepeerreviewer.It determinedthatthecutsetsinthelevel2modelas quantifiedwithoutthereasonforthehigherFTREXresultsis becauseoftheflagfile...Some sensitivitieshavebeenperformed,waythatCAFTA calculatesthetotalvalueofcutsetsalthoughaconclusive determinationhasnotbeenusingMinCutUpperBound.TheLERFresultsfrommaderegardingthecurrentmethodfor quantifyingFTREXwithoutusingtheflagfilehavea significantLERF...([T]heTMImodelusesForte3.0casthe numberofevents greaterthanorequalto0.9.Using quantifier)."SRLE-E4requiresthat LERF betheEPRIAcube(beta)software,itwasshownthatthe quantified consistently aswithcoredamagesumofthecutsetvalues calculatedwithouttheflagfilefrequency.Thisimpliesthatthe LERF quantificationwaslessthanwhenusingtheflagfile.Thisistheresult be conclusively determined asconservative,e.g.,byexpected.Therefore,themethodutilizingtheflagfile quantifying LERFusingForte3

.0c at a greater is conservative and acceptable

.truncationvalue just to assess whethertheuseoftheflagfile produces conservative results.

ResponsetoRequestfor Additional Information LAR-Adoptionof TSTF-425,Revision3DocketNo.50-289 Attachment 1Page8of9WithreferencetotheLAR, Attachment2,Table2-2,FindingDA-B2-01states

"Thereisno evidencethattheintentofthisSRwasmet.Althoughthe componentfailureratesare groupedbysystemand componenttype,thatdoesnot guaranteethatoutliersarenotincludedina group."SRDA-B2(CC-II)requiresexclusionofoutliersinthedefinitionof system/componentfailuregroups.Were outliers appropriatelyexcludedfromgroup definitions?Ifnot,will theirexclusionbepartofthe sensitivityanalysisforanSTI evaluation?

RESPONSEAreviewofthe component grouping has subsequently been performed.Thereisno indicationofoutliersduetotestingor operational characteristics (except potentiallyformanualvalves),norduetopoor performanceofcertain componentsorsystems.Operational characteristics (normalpositionand frequency of manipulation)formanualvalveswasnottakeninto account(Le.,forfailureratepurposes,allmanualvalvesweregroupedtogether).However,therisk significanceofmanualvalvesis negligible; therefore ,noimpactontheresultswouldbeexpectedifthey were grouped differently.WithreferencetoLAR, Attachment2,Table2-2,FindingIFEV-A5-01states:"Several requirements in establishingfloodinitiatingevent frequenciesarenotmet." Specifically citedareSRsIFEV-A5throughIFEV-A7,whichrequireinclusionof plant-specific information and consideration of human-inducedfloodsduring maintenance(CC-II).AreanyofthevalvesthatmaybeassignednewSTlspotentialfloodingsources,suchthatincreasingtheSTIcould increase the frequencyofaflooddueto miscalibration,etc.,ofoneofthesevalves?

RESPONSEWhichvalves

,ifany,are assignednewSTlsusingthe NEI-04-10processisunknownatthistime.However,asindicatedintheLARsubmittalforthisitem,the methodology requires sensitivities for assumptionsinthePRAmodelthatmayaffecttheresultsoftheanalysisorofanygapsto Capability CategoryII.Thiswouldleadtotheseissuesbeing appropriately addressedforanyvalves associatedwitha surveillanceintervalchangeanalysis.

REFERENCES:

1.LetterfromPamelaB.Cowan,Exelon GenerationCompany,LLC,toU.S.Nuclear RegUlatory Commission,"Application for Technical Spec ifications Change Regarding Risk-Informed JustificationfortheRelocationofSpecific Surveillance Frequency RequirementstoaLicenseeControlledProgram(Adoptionof TSTF-425,Revision3),"datedMarch24,2010.

ResponsetoRequestfor Additional Informat ionLAR-Adoptionof TSTF-425 ,Revision3DocketNo.50-289 Attachment 1Page9of92.LetterfromPeterBamford

, U.S.Nuclear Regulatory Commission,toMichaelJ

.Pacilio,ExelonNuclear,"ThreeMileIsland NuclearStation-RequestforAdditional InformationRegardingLicense AmendmentRequesttoAdopt TSTF-425 ,Relocationof Surveillance FrequenciestoaLicensee ControlledProgram(TACNo

.ME3587),"datedJuly 2,2010.

ATIACHMENT2 License Amendment Request Three Mile Island Nuclear Station, Unit 1 DocketNo.50-289 Application for Technical Specification Change RegardingInformed Justification for the Relocation of Specific Surveillance Frequency Requirementstoa Licensee Controlled Program (Adoption of TSTF-425, Revision 3)Revised Proposed Technical Specifications/Bases Pages 4-2a 4-47 Bases(Cont'd)The600ppmb limitinItem4

, Tab le 4.1-3isusedtomeettherequ irementsofSection5.4

.Underothercircumstancestheminimumacceptableboron concentrationwouldhavebeenzeroppmb

.Calibration Calibrat ionshallbeperformedtoassurethepresentationandacquisitionofaccurateinformation

.Thenuclearflux(powerrange)channelsamp lifiersshallbecheckedIn accordance with the Surveillance Frequency Control Program against a heat balance standardandcalibratedif necessary , every shift againstaheatbalancestandard

.Thefrequencyofheatbalancecheckswillassurethatthedifferencebetweentheout-of-core instrumentationandtheheatbalanceremainslessthan4%

.Channelssubjectonlyto"drift"errorsinducedwithintheinstrumentationitselfcantoleratelongerintervalsbetweencalibrations

.Processsystem instrumentation errors inducedbydriftcanbeexpectedtorema inwithinacceptancetolerancesifrecalibrationisperformedattheintervalsofeach refueling periodspecifiedinthe Surveillance Frequency Control Program.Substantialcalibrationshiftswithinachannel(essent iallyachannelfailure)w illberevealedduringroutine check ingandtestingprocedures

.Thus , min imumcalibrationfrequenciessetforthinthe Surveillance Frequency Control Program areconsideredacceptable

.TestingOn-linetestingofreactorprotectionchannelsisrequ iredsemiannuallyin accordance with the Surveillance Frequency Control Programonarotationalbasis.Therotationscheme isdes igned toreducetheprobabilityofanu ndetected fai lure exist ingwithinthesystemandtom inimize thelikelihoodofthesamesystematictesterrorsbeingintroducedintoeachredundantchannel(Reference 1).Surveillance Frequencies are controlled under the Surveillance Frequency Control Program.Therotationscheduleforthe roastor protestionchannelsisasfollows

a)Deleted b)Semiannuallywithonechannel beingtestedevery 46daysonacontinuoussequentialrotation.Thereactorprotectionsysteminstrumentationtestcycleiscontinued withonechannel'sinstrumentation tosted e'tfory 46days.Thefrequencyof every 46daysonacontinuoussoquont ialrotationisconsistent

'....iththecalculationsofReforence2thatindicatethe RPSretainsa highlevelofreliabilityforthis interval.Upondetectionofafailurethatpreventstripactioninachannel

,theinstrumentationassociatedw ith theprotectionparameterfailurewillbetestedintheremainingchannels

.Ifactuationofasafetychanneloccurs,assurancewillberequiredthatactuationwaswith inthelim itingsafetysystemsett ing.Theprotect ionchannelscoincidencelogic

,thecontrolroddrivetripbreakersandtheregulatingcontrolrodpowerSCRselectronictrips

,aretriptestedin accordance with the Surveillance Frequency Control Programquarterlywithonechannel be ing tested every23daysonacontinuoussequentialrotation

.Calculat ions havoshownthatthefrequencyof every23daysmaintainsa h ighle'lelofreliabilityoftheReactorTrip SysteminReference 4.Thetriptestchecksalllogic combinat ionsandistobeperformedonarotationalbas is.Discoveryofafa ilurethatpreventstripactionrequiresthetestingofthe instrumentationassociatedwiththeprotectionparameterfailureintheremainingchannels

.Forpurposesofsurveillance,reactortr iponlossof feedwaterandreactortriponturbinetripareconsideredreactorprotectionsystemchannels

.4-2a Amendment No.78,157 ,181,200,216,255 d.Thebatterywillbesub jectedtoaloadtestonarefueling intePJal 9a&i&in accordancewiththe Surveillance Frequency Control Program.(1)Verifybattery capacityexceedsthatrequiredtomeetdesignloads.(2)Anybatterywhichis demonstratedtohavelessthan85%of manufacturersratingsduringacapacity dischargetestshallbereplacedduringthe subsequentrefuelingoutage

.4.6.3 Pressurizer Heate rsa.Thefo llowingtestsshallbeconductedat leastenseeashrefueling in accordancewiththe Surveillance FrequencyControlProgram:

(1)Pressurizerheatergroups8and9shallbetransferredfromthenormalpowerbustothe emergencypowerbusandenergized.Uponcompletionofthistest,theheatersshallbereturnedtotheirnormalpowerbus.

(2)Demonstratethatthepressur izerheatersbreakeronthe emergencybuscannotbeclosedunt ilthesafeguardssignalisbypassedandcanbeclosedfollowingbypass

.(3)Verifythatfollow inginputoftheEngineeredSafeguardsSignal,thecircuitbreakers

,supplyingpowertothemanuallytransferredloadsfor pressurizerheatergroups8and9,havebeentripped

.BasesThetestsspecifiedaredesignedto demonstratethatonediesel generator w illprovidepowerforoperationof safeguardsequipment.Theyalsoassurethatthe emergency generatorcontrolsystemandthecontro lsystemsforthe safeguards equ ipment wi ll function automaticallyintheeventofalossofnormala-cstationservicepoweroruponthereceiptofanengineered safeguards ActuationSignal.Theintentofthemonthly periodictestsisto demonstratethediese l capab ilitytocarrydesignbasisaccident (LOOP/LOCA)load.Thetestshouldnotexceedthediesel2000-hr.ratingof3000kW.Theautomatictripp ingofmanually transferredloads,onanEngineered SafeguardsActuationSignal

,protectsthediesel generatorsfromapotentialoverloadcondition.Thetestingfrequencyspecifiedisintendedtoidentifyandpermitcorrectionofanymechanicalorelectrical deficiencybeforeitcanresultinasystemfailure.Thefueloilsupply,startingcircuits

, andcontrolsare continuouslymonitoredandanyfau ltsarealarmedandindicated

.Anabnormalconditioninthesesystemswouldbes ignaled w ithouthavingtoplacethe diesel generatorsontest.Prec ipitousfailureofthestationbatteryisextremelyunlikely.The Ssurveillancespesifiedisthat

'Nhishhasbeendemonstratedovertheyearstoprovideanindisationofasellbecoming unsePJiceablelongbeforeit fa#sFrequencies are controlled under the Surveillance Frequency Control Program.ThePORVhasaremotelyoperatedblockvalvetoprovideapositive shutoffcapabilityshouldthereliefvalvebecomeinoperable.Theelectricalpowerforboththereliefvalveandtheblockvalve issuppliedfromanESFpowersourcetoensuretheabilitytosealthispossibleRCSleakagepath

.The requirementthatam inimumof107kwofpressurizerheatersandtheirassociatedcontrolsbecapableofbeingsuppliedelectricalpowerfroman emergencybusprovidesassurancethattheseheaterscanbeenergizedduringalossofoffsitepowercondit iontomaintainnaturalcirculation.

4-47 Amendment No.78,157,167,175

,ECRTM 0700119