ML14325A752

Grand Gulf, Unit 1 - License Amendment Request Application to Revise Current Fluence Methodology

ML14325A752
Person / Time
Site:	Grand Gulf
Issue date:	11/21/2014
From:	Mulligan K J Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML14325A758	List: ML14325A752
References
GNRO-2014/00080
Download: ML14325A752 (16)

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Q EntergyOperations, Inc.P.O.Box756PortGibson,MS39150KevinMulliganSiteVicePresidentAh2&3C.0.GrandGulfNuclearStationttacmentsontainPRPRIETARYInformation Tel.(601)437-7500GNRO-2014/00080 Nov21,2014u.s.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, DC20555-0001

REFERENCES:

LicenseAmendment RequestApplication toReviseGrandGulfNuclearStationUnit1'sCurrentFluenceMethodology from0Effective FullPowerYears(EFPY)ThroughtheEndofExtendedOperations toaSingleFluenceMethodGrandGulfNuclearStation,Unit1DocketNo.50-416LicenseNo.291.SeverityLevelIVnon-cited violation of10CFR50.59,"Changes, Tests,andExperiments involving thelicensee's failuretoobtainalicenseamendment pursuantto10CFR50.90priortoimplementing anewmethodofevaluation fordetermining reactorvesselneutronfluence;GrandGulfNuclearStation-NRCIntegrated Inspection Report05000416/2013004, datedNovember27,20132.U.S.NuclearRegulatory Commission Letter,"Requests forAdditional Information fortheReviewoftheGrandGulfNuclearStation,LicenseRenewalApplication,"

datedAugust28,2013(Accession No.ML13227A394)3.GrandGulfNuclearStationLetter,"Response toRequestsforAdditional Information (RAI)set47,"datedSeptember 23,2013(Accession No.ML13266A368) 4.U.S.NuclearRegulatory Commission Regulatory Guide,Regulatory Guide1.190,datedMarch2001(Accession No.ML010890301)

DearSirorMadam:

Inaccordance withtheprovisions ofSection50.90ofTitle10CodeofFederalRegulations (10CFR),EntergyOperations, Inc.(Entergy) issubmitting arequestforanamendment toreviseourexistinglicensebasisforGrandGulfNuclearStation(GGNS),Unit1.Theproposedamendment istoreviseGrandGulfNuclearStation,Unit1'slicensebasistoadoptasinglefluencemethod.Thischangeisneededtoaddressalegacyissueinwhichthe GNRO-2014/000BO Page2of3currentmethodwasdetermined tobeutHizedwithoutreceiving priorNuclearRegulatory Commission (NRC)approval.

Attachment 1providesadescription oftheproposedchange.Attachment 2providesthetopicalreportfromMPMachinery andTesting,LLC.Attachment 3providesthereportdocumenting theapplication ofthesinglefluencemethodatGGNS.ThisreportalsoappliestotheMaximumExtendedLoadLineLimitPlus(MELLLA+)

LicenseAmendment Request(LAR)inletter2013/00012 (Accession No.ML13269A140).

Althoughthisrequestisneitherexigentnoremergency, yourpromptreviewisrequested.

Onceapproved, theamendment shallbeimplemented within60days.MPMachinery andTesting,LLC(MPM)considers theinformation providedinAttachments 2and3tobeproprietary andtherefore exemptfrompublicdisclosure pursuantto10CFR2.390.Theproprietary information wasprovidedtoEntergyinanMPMtransmittal.

Therefore, onbehalfofMPM,EntergyrequeststowithholdAttachments 2and3frompublicdisclosure inaccordance with10CFR2.390(b)(1).

Thislettercontainsnonewcommitments.

Ifyouhaveanyquestions orrequireadditional information, pleasecontactMr.JamesNadeauat(601)437-2103.

Ideclareunderpenaltyofperjurythattheforegoing istrueandcorrect.ExecutedonNovember21,2014.Sincerely, KJM/rasAttachments:

1.AnalysisofProposedSingleFluenceMethodology 2.TopicalReportfromMPMachinery andTesting,LLC:MPM-614993, "Benchmarking ofMPMMethodsforBWRNeutronTransport Calculations,"

November, 2014.3.SingleFluenceMethodAppliedtoGGNS:MPM-B14779 Revision1,"NeutronTransport AnalysisforGrandGulfNuclearStation,"

November, 2014.cc:Seenextpage GNRO-2014/00080 Page3of3cc:withAttachment andEnclosures U.S.NuclearRegulatory Commission ATTN:Mr.JohnDaily,NRRlDLRMailStopOWFN/11F111555Rockville PikeRockville, MD20852-2378 cc:withoutAttachment andEnclosures U.S.NuclearRegulatory Commission ATTN:Mr.MarkDapas,(w/2)RegionalAdministrator, RegionIV1600EastLamarBoulevard Arlington, TX76011-4511 NRCSeniorResidentInspector GrandGulfNuclearStationPortGibson,MS39150U.S.NuclearRegulatory Commission ATTN:Mr.AlanWang,NRRlDORL(w/2)MailStopOWFN8B1Washington, DC20555-0001 Dr.MaryCurrier,M.D.,M.P.HStateHealthOfficerMississippi Department ofHealthP.O.Box1700Jackson,MS39215-1700 Attachment 1GNRO-2014/00080 AnalysisofProposedSingleFluenceMethodology Attachment 1toGNRO-2014/000BO Page1of121.0DESCRIPTION Theproposedamendment revisestheGrandGulfNuclearStation,Unit1(GGNS)licensebasestoadoptasinglefluencemethodology from0Effective FullPowerYears(EFPY)throughtheendofextendedoperations.

Thischangeisneededtoaddressalegacyissueinwhichthecurrentmethodwasdetermined tohaverequiredNuclearRegulatory Commission (NRC)approvalpriortobeingutilized, andalsoappliestotheMaximumExtendedLoadLineLimitPlusAnalysisPlus(MELLLA+)

LicenseAmendment Request(LAR)(Accession No.ML13269A140).

Thenewfluencemethodology isreferredtobelowasthe"singlefluencemethod"toindicatethatallcalculations areperformed inaconsistent manner.Themethodology isdescribed indetailinReferences 1and2whichgivetheresultsofthemethodology benchmarking analysisandtheapplication ofthemethodology totheGGNSfluenceanalysiscoveringoperation forthefirst21fuelcycles.2.0BACKGROUND DuringtheGGNSLicenseRenewalprocess,itwasdetermined thatthecurrentfluencemethodology shouldhavereceivedNRCapprovalpriortobeingutilized.

ThisresultedinaSeverityLevelIVNon-Cited Violation (NCV)of10CFR50.59,"Changes, Tests,andExperiments" involving failuretoobtainalicenseamendment pursuantto10CFR50.90priortoimplementing anewmethodofevaluation fordetermining reactorvesselneutronfluence,asdocumented intheGrandGulfNuclearStation-NRCIntegrated Inspection Report05000416/2013004, datedNovember27,2013.LicenseRenewalApplication (LRA)LicenseAmendment RequestResponsetoRequestforAdditional Information (RAI),set47,question5response, stated,inpart:GGNSRAI4.2.1-2c Response5)Asupplemental responsetothisRAIisbeingdeveloped andwillbeprovidedtotheNRC.Thesupplemental responsewillprovidetheanswerstothefollowing questions:

a)Pleaseprovide fluencevaluesthathavebeendetermined fromBeginning OfLifetoEndofLifeExtendedinaccordance withasinglemethod.i)IfthemethodisNRC-approved insofarasitappliestovesselfluencecalculations, providethereference tothestaff-accepted methodology.

ii)IfthemethodisnotNRC-approved, providetheplant-specific calculations anddocumentation, andincludesufficient information, toenabletheNRCstafftodetermine whetherthecalculation adherestoNRCRegulatory Guide(RG)1.190,"Calculational andDosimetry MethodsforDetermining PressureVesselNeutronFluence,"

orotherjustification asrequiredtoestablish thatthefluencecalculation isacceptable.

iii)RefertoRegulatory Position3,"Reporting,"

forthespecificdocumentation requiredtoestablish adherence toNRCRG1.190.

Attachment 1toGNRO-2014/00080 Page2of123.0TECHNICAL ANALYSIS3.1Applicability EntergyhasreviewedtheU.S.NuclearRegulatory Commission Regulatory Guide,RG1.190(Reference 3).Thisguidedescribes theapplication andqualification ofamethodology acceptable totheNRCstafffordeterminingthe best-estimate neutronfluenceexperienced bymaterials inthebeltlineregionoflightwaterreactor(LWR)pressurevessels,aswellasfordetermining theoveralluncertainty associated withthosebest-estimate values.Entergyhasconcluded thattheproposedfluencemethodology complieswiththeguidanceofRG1.190,andtherefore isappropriate tobeutilizedatGGNS.3.2Determination ofcompliance withRG1.1903.2.1Regulatory Position(RP)Compliance Discussion.

FLUENCECALCULATION METHODSRP1.3FluenceDetermination.

Absolutefluencecalculations, ratherthanextrapolated fluencemeasurements, mustbeusedforthefluencedetermination.

GGNSResponse:

Allcalculations performed usingtheGGNSproposedmethodology useabsolutefluencecalculations.

Thismeetstherequirement ofRP1.3.

Attachment 1toGNRO-2014/00080 Page3of12RP1.1.1ModelingData.Thecalculation modeling(geometry, materials, etc.)shouldbebasedondocumented andverifiedplant-specific data.GGNSResponse:

TheGGNSproposedmethodology isbasedondocumented andverifiedplant-specific data.Further,thecalculations useas-builtdataforplantstructures andmaterialcompositions wheneverthesedataareavailable.

Thefueldataisspecificforeachfuelcycleandincludesresultsforpowerdistributions andwaterdensities takenfromthefueldepletion analysis.

Thismeetstherequirement ofRP1.1.1.RP1.1.2NuclearData.ThelatestversionoftheEvaluated NuclearDataFile(ENDF/B)shouldbeusedfordetermining nuclearcross-sections.

Cross-section setsbasedonearlierorequivalent nuclear-data setsthathavebeenthoroughly benchmarked arealsoacceptable.

Whentherecommended cross-section datachange,theeffectofthesechangesonthelicensee-specific methodology mustbeevaluated andthefluenceestimates updatedwhentheeffectsaresignificant.

GGNSResponse:

Thecalculations usetheBUGLE-96crosssectionsetwhichisbasedonthelatestversion(VI)oftheEvaluated NuclearDataFile(ENDF/B).

Thismeetstherequirement ofRP1.1.2.RP1.1.2Cross-Section AngularRepresentation.

Indiscreteordinates transport calculations, aP3angulardecomposition ofthescattering cross-sections (ataminimum)mustbeemployed.

GGNSResponse:

Allcalculations useaP3angulardecomposition inaccordance withregulatory guide.Thismeetstherequirement ofRP1.1.2.RP1.1.2Cross-Section GroupCollapsing.

Theadequacyofthecollapsed joblibrarymustbedemonstrated bycomparingcalculations forarepresentative configuration performed withboththemasterlibraryandthejoblibrary.GGNSResponse:

Allcalculations areperformed withtheBUGLE-96librarywhichiscollapsed to47neutrongroups.Thislibraryhasbeenthoroughly benchmarked.

Thismeetstherequirement ofRP1.1.2.RP1.2NeutronSource.Thecoreneutronsourceshouldaccountforlocalfuelisotopics and,whereappropriate, theeffectsofmoderator density.Theneutronsourcenormalization andenergydependence mustaccountforthefuelexposuredependence ofthefissionspectra,thenumberofneutronsproducedperfission,andtheenergyreleasedperfission.GGNSResponse:

Theneutronsourceiscalculated takingintoaccountchangesinneutronsperfission,energyperfission,andtheaveragefissionspectrumwhichdevelopsastheUranium-235 isburnedandother Attachment 1toGNRO-2014/00080 Page4of12isotopes, suchasPu239,increaseinfissionfraction.

Thismeetstherequirement ofRP1.2.RP1.2End-of-Life Predictions.

Predictions ofthevesselend-of-life fluenceshouldbemadewithabest-estimate orconservative genericpowerdistribution.

Ifabestestimateisused,thepowerdistribution mustbeupdatedifchangesincoreloadings, surveillance measurements, orotherinformation indicateasignificant changeinprojected f1uencevalues.GGNSResponse:

GGNShascalculated thefluenceforeverycycleuptothepresent.Thisgivesthemostaccuratevalueofthepresentfluence.Extrapolations tofuturetimesaremadeusingbestestimatevaluesoffuturefueldesignsinacycle21bestestimateprojection cycle.Aschangesinfuelcoreloadingsaremade,updatedextrapolations willbemade.Further,thefluxvaluesfromthecycle21transport calculation weremultiplied withafactorof1.1appliedforprojection toexposures aftercycle21.This10%)conservatism wasappliedbyEntergytoensurethatfluenceestimates remainconservative.

Periodic cycletransport updatesareplannedtoensurethe100/0factoradequately coversfutureas-burned fluxes.Thismeetstherequirement ofRP1.2.RP1.3.1SpatialRepresentation.

Discreteordinates neutrontransport calculations shouldincorporate adetailedradialandazimuthal-spatial meshof-2intervals perinchradially.

Thediscreteordinates calculations mustemploy(ataminimum)anSaquadrature and(atleast)40intervals peroctant.GGNSResponse:

Thepresentmethodology meetsorexceedstheserequirements.

All3Dcalculations wereperformed withanS16quadrature.

TheR-8modelincluded215meshpointsintheradialdirection.

Theradialmeshcoverstherangefromthecenterofthecoretoabout15inchesintothebiological shield.Thelargenumberofmeshpointswasusedtoaccurately calculate theneutronfluxtransport fromthecoreedgetotheoutsideofthevessel.Intheazimuthal direction, 185meshpointswereusedtomodelaquadrantofthereactor.Inspection ofthefuelloadingpatternsindicated thatonlyminordeviations fromquartercoresymmetrywerepresent,andthesewerenotsignificant.

However,therearesomedeviations fromoctantfuelsymmetryandthese,togetherwiththequadrantsymmetryofthejetpumps,ledtotheuseofthequartercoremodel.The185azimuthal pointsprovidedgooddefinition ofthevariation ofthecoreedgewithangleandaccurately definedtheazimuthal fluxvariation intheshroud.Intheaxialdirection, the3DmodelextendspastBAFtoabout18inchesbelowtheH7shroudweld.ThemodeloftheregionabovethetopguideextendsaxiallypastthetopguideweldH1byanaxialextentof18inches.Thisresultedinatotalof246meshpointsintheaxialdirection, with105axialmeshesin Attachment 1toGNRO-2014/00080 Page5of12thecoreregion.Thisresultedinamodelwithover9.7millionmeshesinthe3Dmodel.Thismeets therequirement ofRP1.3.1.RP1.3.1MultipleTransport Calculations.

Ifthecalculation isperformed usingtwoormore"bootstrap" calculations, theadequacyoftheoverlapregionsmustbedemonstrated.

GGNSResponse:

Itwasnotnecessary tousebootstrapping forthesecalculations sothisrequirement doesnotapply.RP1.3.2PointEstimates.

Ifthedimensions ofthetallyregionorthedefinition oftheaverage-flux regionintroduce abiasinthetallyedit,theMonteCarloprediction shouldbeadjustedtoeliminate thecalculational bias.Theaverage-flux regionsurrounding thepointlocationshouldnotincludematerialboundaries orbelocatednearreflecting,

periodic, orwhiteboundaries.

GGNSResponse:

Thisrequirement onlyappliestoMonteCarlocalculations whicharenotusedhere.Variancereduction methodswerenotused.RP1.3.2Statistical Tests.TheMonteCarloestimated meanandrelativeerrorshouldbetestedandsatisfyallstatistical criteria.

GGNSResponse:

Thisrequirement onlyappliestoMonteCarlocalculations whicharenotusedhere.RP1.3.2VarianceReduction.

Allvariancereduction methodsshouldbequalified bycomparison withcalculations performed withoutvariancereduction.

GGNSResponse:

Thisrequirement onlyappliestoMonteCarlocalculations whicharenotusedhere.RP1.3.3CapsuleModeling.

Thecapsulefluenceisextremely sensitive tothegeometrical representation ofthecapsulegeometryandinternalwaterregion,andtheadequacyofthecapsulerepresentation andmeshmustbedemonstrated.

GGNSResponse:

Thecapsulegeometryismodeledusingas-builtdrawings.

Thewaterbetweenthecapsuleandthevesselsurfaceisalsomodeledusingbuiltdrawings.

Themeshisrefinedintheregionofthecapsuleandtheadequacyofthemeshhasbeendemonstrated bytheaccuracyoftheCIMratiosforthecycle1dosimetry analysis.

Thismeetstherequirement ofRP1.3.3.

Attachment 1toGNRO-2014/00080 Page6of12RP1.3.3SpectralEffectsonRTNDT.Inordertoaccountfortheneutronspectrumdependence ofRTNDT,whenitisextrapolated fromtheinsidesurfaceofthepressurevesseltotheT/4and3T/4vessellocations usingtheE>1-MeVfluence,aspectralleadfactormustbeappliedtothefluenceforthecalculation ofaRTNDT.GGNSResponse:

Thisrequirement onlyappliestoextrapolation throughthevesselanddoesnotaffectthebenchmark calculations.

However,whenfluencewithinthevesselisrequired, thedisplacement peratom(dpa)extrapolation methodology isappliedtovesselcalculations asspecified inRG1.99,Revision2.Dataaresuppliedtoenableextrapolation usingdpacalculated extrapolation orusingRG1.99Rev.2extrapolation toaccountforthespectralshift.Thismeetstherequirement ofRP1.3.3.RP1.3.5CavityCalculations.

Indiscreteordinates transport calculations, theadequacyoftheS8angularquadrature usedincavitytransport calculations mustbedemonstrated.

GGNSResponse:

Nocavitydosimetry workhasbeenperformed atGGNS.RP1.4.1,1.4.2,1.4.3MethodsQualification.

Thecalculational methodology mustbequalified byboth(1)comparisons tomeasurement andcalculational benchmarks and(2)ananalyticuncertainty analysis.

Themethodsusedtocalculate thebenchmarks mustbeconsistent (totheextentpossible) withthemethodsusedtocalculate thevesselfluence.Theoverallcalculational biasanduncertainty mustbedetermined byanappropriate combination oftheanalyticuncertainty analysisandtheuncertainty analysisbasedonthecomparisons tothebenchmarks.

GGNSResponse:

Anextensive benchmarking programhasbeencarriedouttoqualifytheMPMneutrontransport methodology.

Alloftherequirements ofRG1.190havebeenmet.Inparticular, allC/Mresultsfallwithinallowable limits(+1-20%),anditwasdetermined thatnobiasneedbeappliedtoMPMfluenceresults.Theuncertainty analysisindicates thatallfluenceresultsinthebeltlineregionhaveuncertainty oflessthan20%.Theresultsofthisanalysisaredocumented inReferences 1and2.Thismeetstherequirement ofRP1.4.1,1.4.2,and1.4.3.RP1.4.3FluenceCalculational Uncertainty andBiasEstimation.

Thevesselfluence(1sigma)calculational uncertainty mustbedemonstrated tobeS200kforRTPTSandRTNDTdetermination.

Intheseapplications, ifthebenchmark comparisons indicatedifferences greaterthan20%,thecalculational modelmustbeadjustedoracorrection mustbeappliedtoreducethedifference betweenthefluenceprediction andtheupper1-sigmalimittowithin200/0.Forotherapplications, theaccuracyshouldbedetermined usingtheapproachdescribed inRegulatory Position1.4,andanuncertainty allowance shouldbeincludedinthefluenceestimateasappropriate inthespecificapplication.

Attachment 1toGNRO-2014/00080 Page7of12GGNSResponse:

Anextensive evaluation ofallcontributors totheuncertainty inthecalculated fluencewasmadefortheBWRplantcalculations performed todate.Thisevaluation indicated thattheuncertainty incalculated fluencesinthereactorbeltlineregionisbelow200kasspecified intheguide.Inaddition, thecomparisons withmeasurements indicateagreement wellwithinthe20%limit.Theagreement ofcalculations withmeasurements towithin+/-200/0uncertainty indicates thattheMPMcalculations canbeappliedforfluencedetermination withnobias.Thismeetstherequirement ofRP1.4.3.FLUENCEMEASUREMENT METHODSRP2.1.1SpectrumCoverage.

Thesetofdosimeters shouldprovideadequatespectrumcoverage.

GGNSResponse:

GGNSdoesnothavedosimetry setsinstalled toprovidespectrumdefinition.

ThisisincommonwithGEBWRswhichhaveonlylimiteddosimetry installed insurveillance capsules.

TheGGNSdosimetry analyzedtodateisfromironwiresattachedtoasurveillance capsuleandremovedafterthefirstcycleofoperation.

Calculated neutronspectraarevalidated usingthedetailedmeasurements fortestreactorsandthecalculational benchmark includedinRG1.190.Resultsaredocumented inReference 1.RP2.1.1Dosimeter NuclearandMaterialProperties.

Useofdosimeter materials shouldaddressmelting,oxidation, materialpurity,totalandisotopicmassassay,perturbations byencapsulations andthermalshields,andaccuratedosimeter positioning.

Dosimeter half-life andphotonyieldandinterference shouldalsobeevaluated.

GGNSResponse:

TheGGNSdosimetry wirematerialcharacterization wasperformed byGE(Reference 4).Allnuclearconstants andparameters usedinthedosimetry countingandanalysisfollowASTMstandardprocedures andusevalidated nuclearconstants.

Thismeetstherequirement ofRP2.1.1.RP2.1.2Corrections.

Dosimeter-response measurements shouldaccountforfluenceratevariations, isotopicburnupeffects,detectorperturbations, selfshielding, reactioninterferences, andphotofission.

GGNSResponse:

Thefluenceratevariations forthedosimetry removedaftercycle1wereexplicitly takenintoaccountbydividingthecycleinto9segmentsandcalculating thecapsulefluencerateforeachsegment.Theisotopicburnupeffectsareaccurately accounted foraspreviously discussed.

Attachment 1toGNRO-2014/00080 Page8of12Theothereffectshaveallbeenevaluated tobesmallornotapplicable.

Thismeetstherequirement ofRP2.1.2.RP2.1.3ResponseUncertainty.

Anuncertainty analysismustbeperformed fortheresponseofeachdosimeter.

GGNSResponse:

Uncertainty analysesforeachdosimeter havebeenreportedinallofthesurveillance capsulereportsperformed byMPM.ForGGNS,GEperformed thecycle1dosimetry analysis(Reference 4).Theuncertainty foreachcycle1dosimeter wasreported.

Thismeetstherequirement ofRP2.1.3.RP2.2Validation.

Detector-response calibrations mustbecarriedoutperiodically inastandardneutronfield.GGNSResponse:

Regarding theGGNScycle1dosimetry workdonebyGE,responsecalibrations havebeencarriedoutinthepastusingdocumented procedures.

TheGEradiochemistry laboratory participated inpastinterlaboratory dosimetry measurement calibration programsbothforfastreactorirradiations (Interlaboratory LMFBRReactionRateProgram)(Reference 5)andlightwaterreactorirradiations (LWRSurveillance Dosimetry Improvement Program)(Reference 6).Intheseprograms, dosimeters wereirradiated instandardneutronfieldsandmeasuredbymultiplelaboratories.

Theseprogramsdemonstrated theaccuracyofmeasurements andimproyedthestate-of-the-art.

Regulatory Position2.2isdated.Theaboveprogramsarecompleted andstandardfielddetectorresponseirradiations arenolongerdone.Theseprogramsservedtheirpurposetodemonstrate thevalidityofmeasurement uncertainty estimates.

Althoughthecalibration programsenvisioned continuing useofstandardfieldirradiations, thesearenolongerconsidered necessary andmoderncountingpractices involvetheuseofNISTtraceable mixedgammasourcestoprovideaccurateenergyandefficiency spectrometer calibrations.

RP2.3Fast-Neutron Fluence.TheE>1MeVfast-neutron fluenceforeachmeasurement locationmustbedetermined usingcalculated spectrum-averaged cross-sections andindividual detectormeasurements.

Asanalternative, thedetectorresponses maybeusedtodetermine reactionprobabilities oraveragereactionrates.GGNSResponse:

Measurement-to-Calculation ratiosaredetermined foreachdosimeter measurement usingcalculated detectorresponses (References 1and2).Thismeetstherequirement ofRP2.3.

Attachment 1toGNRO-2014/00080 Page9of12RP2.3Measurement-to-Calculation Ratios.TheMICratios,thestandarddeviation, andbiasbetweencalculation andmeasurement, mustbedetermined.

GGNSResponse:

TheMICratios,standarddeviations, andcomparisons betweencalculation andmeasurement havebeendoneandhavebeenreportedasdiscussed earlier(References 1and2).Thismeetstherequirement ofRP2.3.REPORTING PROVISIONS RP3.1Neutronfluenceanduncertainties detailsoftheabsolutefluencecalculations, associated methodsqualification, andfluenceadjustments (ifany)shouldbereported.

Justification andadescription ofanydeviations fromtheprovisions ofthisguideshouldbeprovided.

GGNSResponse:

ThereportontheGGNScalculations meetsallRG1.190reporting requirements (Reference 2).Thismeetstherequirement ofRP3.1.RP3.2Calculated multigroup neutronfluencesandfluenceratesshouldbereported.

GGNSResponse:

Becauseoftheextensive amountofdata,onlythefluencedistributions forneutronswithenergygreaterthan1MeVarereported, exceptforthevesselwhereneutronswithenergygreaterthan0.1MeVanddpaarealsoreported.

Themultigroup fluenceratesarepermanently storedforfutureaccessifrequired.

Thesearenotseenashavinganyapplication exceptforpossiblefuturedosimetry analysis.

Multigroup fluxvaluesarereadilyavailable foralldosimetry locations.

Thismeetstherequirement ofRP3.2.RP3.2Thevalueandbasisofanybiasormodeladjustment madetoimprovethemeasurement-to-calculation agreement mustbereported.

GGNSResponse:

Nobiasisobservedandnoneisapplied(References 1and2).Thismeetstherequirement ofRP3.2.RP3.3Calculated integralfluencesandf1uenceratesforE>1MeVandtheiruncertainties shouldbereported.

GGNSResponse:

Theseareallreported(Reference 2).Thismeetstherequirement ofRP3.3.RP3.4Measuredandcalculated integralE>1MeVfluencesorreactionratesanduncertainties foreachmeasurement locationshouldbereported.

TheMICratiosandthespectrumaveragedcross-section shouldalsobereported.

Attachment 1toGNRO-2014/000BO Page10of12GGNSResponse:

Thesearereportedforalldosimetry locations (References 1and2).Thismeetstherequirement ofRP3.4.RP3.5Theresultsofthestandardfieldvalidation ofthemeasurement methodshouldbereported.

GGNSResponse:

Notapplicable.

SpecificActivities andAverageReactionRatesRP3.5Thespecificactivities attheendofirradiation andmeasuredaveragereactionrateswithuncertainties shouldbereported.

GGNSResponse:

Thisiscontained inallreportswithmeasureddosimetry data.Thismeetstherequirement ofRP3.5.RP3.5Allcorrections andadjustments tothemeasuredquantities andtheirjustification shouldbereported.

GGNSResponse:

Nocorrections made.Thismeetstherequirement ofRP3.5.CONCLUSIONS Inconclusion, theproposedsinglefluencemethodfrom0EFPYthrough theendofextendedoperations isinfullcompliance withRG1.190,anditsreferenced regulations, andensuresthefluenceinputstotheanalysisareappropriate.

Therefore, theadoptionofthissinglefluencemethodisconsidered acceptable andmaintains applicable safetymargins.4.0REGULATORY SAFETYANALYSISNRCRG1.190describes theapplication andqualification ofamethodology acceptable totheNRCstafffordetermining thebest-estimate neutronfluenceexperienced bymaterials inthebeltlineregionoflightwaterreactor(LWR)pressurevessels,aswellasfordetermining theoveralluncertainty associated withthosebest-estimate values.Thisrequestforlicenseamendment providestheGGNS-specific actionstoresolvethenonconforming condition.

GGNShasdetermined thattheproposedchangesdonotrequireanyexemptions orrelieffromregulatory requirements, anddonotaffectconformance withanydraftGeneralDesignCriteriadifferently thandescribed intheGGNSUFSAR,asdescribed below.4.1Applicable Regulatory Requirements/Criteria Regulatory requirement 10CFRPart50,"Domestic Licensing ofProduction andUtilization Facilities" AppendixG,"Fracture Toughness Requirements,"

and10CFR50.61,"Fracture Attachment 1toGNRO-2014/00080 Page11of12Toughness Requirements forProtection AgainstPressurized ThermalShockEvents",areregulations thatensurethestructural integrity ofthereactorpressurevesselfor cooledpowerreactors.

Chapter15,AccidentAnalysis, oftheStandardReviewPlan(NUREG-0800, StandardReviewPlanfortheReviewofSafetyAnalysisReportsforNuclearPowerPlants)assumesthepressurevesseldoesnotfail.Theproposedsinglefluencemethodfrom0EFPYthrough theendofextendedoperations isinfullcompliance withRG1.190anditsreferenced regulations andensuresthefluenceinputstotheanalysisarecorrect.Inconclusion, basedontheconsiderations discussed above,(1)thereisreasonable assurance thatthehealthandsafetyofthepublicwillnotbeendangered byoperation intheproposedmanner,(2)suchactivities willbeconducted incompliance withtheCommission's regulations, and(3)theissuanceoftheamendment willnotbeinimicaltothecommondefenseandsecurityortothehealthandsafetyofthepublic.4.2NoSignificant HazardsConsideration Determination Entergyrequestsadoptionoftheproposedsinglefluencemethodfrom0EFPYthroughtheendofextendedoperations.

Entergyhasevaluated whetherornotasignificant hazardsconsideration isinvolvedwiththeproposedamendment(s) byfocusingonthethreestandards setforthinTitle10CodeofFederalRegulations (10CFR)50.92,"Issuance ofAmendment,"

asdiscussed below:1.Doestheproposedchangeinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated?

Response

No.Theproposedchangeadoptsasinglefluxmethodology.

WhileChapter15,AccidentAnalysis, oftheStandardReviewPlan(NUREG-0800, StandardReviewPlanfortheReviewofSafetyAnalysisReportsforNuclearPowerPlants)assumesthepressurevesseldoesnotfail,thefluxmethodology isnotaninitiator toanyaccidentpreviously evaluated.

Accordingly, theproposedchangetotheadoptionofthefluxmethodology hasnoeffectontheprobability ofanyaccidentpreviously evaluated.

Therefore, theproposedchangedoesnotinvolveasignificant increaseintheprobability orconsequences ofanaccidentpreviously evaluated.

2.Doestheproposedchangecreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated?

Response

No.Theproposedchangeadoptsafluxmethodology.

Thechangedoesnotinvolveaphysicalalteration oftheplant(i.e.,nonewordifferent typeofequipment willbeinstalled) orachangeinthemethodsgoverning normalplantoperations.

Thechangedoesnotalterassumptions madeinthesafetyanalysisregarding fluence.

Attachment 1toGNRO-2014/00080 Page12of12Therefore, theproposedchangedoesnotcreatethepossibility ofanewordifferent kindofaccidentfromanyaccidentpreviously evaluated.

3.Doestheproposedchangeinvolveasignificant reduction inamarginofsafety?Response:

No.Theproposedchangeadoptsasinglefluencemethodology.

Theproposedchangedoesnotalterthemannerinwhichsafetylimits,limitingsafetysystemsettingsorlimitingconditions foroperation aredetermined.

Theproposedchangeensuresthatthemethodology usedforfluenceisincompliance withRG1.190requirements.

Therefore, theproposedchangedoesnotinvolveasignificant reduction inamarginofsafety.Basedontheabove,Entergyconcludes thattheproposedchangepresentsnosignificant hazardsconsideration underthestandards setforthin10CFR50.92(c),

and,accordingly, afindingof"nosignificant hazardsconsideration" isjustified.

5.0 ENVIRONMENTAL

CONSIDERATION Theproposedchangewouldnotchangearequirement withrespecttoinstallation oruseofafacilitycomponent locatedwithintherestricted area,asdefinedin10CFR20,andwouldnotchangeaninspection orsurveillance requirement.

Theproposedchangedoesnotinvolve(i)asignificant hazardsconsideration, (ii)asignificant changeinthetypesorsignificant increaseintheamountsofanyeffluentthatmaybereleasedoffsite,or(iii)asignificant increaseinindividual orcumulative occupational radiation exposure.

Accordingly, theproposedchangemeetstheeligibility criterion forcategorical exclusion setforthin10CFR51.22(c)(9).Therefore, pursuantto10CFR51.22(b),

noenvironmental impactstatement orenvironmental assessment needbepreparedinconnection withtheproposedchange.

6.0REFERENCES

1.MPM-614993, "Benchmarking ofMPMMethodsforBWRNeutronTransport Calculations,"

November, 2014.2.MPM-814779, "NeutronTransport AnalysisforGrandGulfNuclearStation",

November2014.3.U.S.NuclearRegulatory Commission, Regulatory Guide1.190,datedMarch2001(Accession No.ML010890301)4."FluxWireDosimeter Evaluation forGrandGulfNuclearPowerStation,"

GEReport35-0387,April1987.5.W.N.McElroy,"DataDevelopment andTestingforFastReactorDosimetry

",Nucl.Tech.25,177(1975).6.R.GoldandW.N.McElroy,"TheLightWaterReactorVesselSurveillance Dosimetry Improvement Program(LWR-PV-SDIP):

PastAccomplishments, RecentDevelopments, andFutureDirections,"

ReactorDosimetry:

Methods,Applications, andStandardization, ASTMSTP1001,HarryFarrarandE.P.Lippincott, eds.,AmericanSocietyforTestingandMaterials, Philadelphia, 1989,pp44-61.