ML14231A067

Meeting Slide for Watts Bar Nuclear Plant, Unit 1 Tpbar Loading Increase LAR Pre-Submittal Meeting

ML14231A067
Person / Time
Site:	Watts Bar
Issue date:	08/11/2014
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
Lingam S
Shared Package
ML14231A129	List: ML14231A067 ML14231A072
References
Download: ML14231A067 (11)

Text

8/11/2014 1

August14,2014 Nuclear WattsBarTPBARLoadingIncreaseLAR PreSubmittalMeeting Introduction 2

Nuclear

• PurposeofMeeting

- UpdateNRCManagementonTVAsPlantoSubmita LicenseAmendmentRequest(LAR)inJanuary2015 toIncreaseAllowableTPBARLoadingforWattsBar Unit1

8/11/2014 2

Agenda 3

Nuclear

• Introduction JimLemons

• Background MarkBurzynski

• DOETPBARLoadingPlans CarlaBorrelli

• TritiumPermeationExperience CherylThornhill

• ProjectedPathwayExposures MarkBurzynski

• PlantModifications CarlaBorrelli

• PostLOCAShutdownMarginAnalysis MarkBurzynski

• LicensingPlanandSchedule MarkBurzynski

• ClosingComments JimLemons

Background

4 Nuclear

• Background

- LicenseAmendment40IssuedonSeptember23,2002 AuthorizedLoadingUpto2304TPBARs

• AllowedLoadingSubsequentlyReducedtoAddressPost LOCAShutdownMarginIssues

- TVALetterDatedMarch22,2005NotifiedNRCofInterim CumulativeTPBARTritiumReleaseLimits

• WhileHigherthanProjectedPermeationRateswere Investigated

- LicenseAmendment77IssuedonMay4,2009Authorized LoadingUpto704TPBARs

8/11/2014 3

DOETPBARLoadingPlans 5

Nuclear

• DOETPBARLoadingPlansforWattsBarUnit1:

Cycle Date TPBARLoading TechSpecLimit C12 October 2012 544 704 C13 April2014 704 704 C14 October2015 704 704 C15 March2017 1104 1792*

C16 October2018 1504 1792*

C17 April2020 1792 1792*

• Proposed TritiumPermeation Experience(1/2) 6 Nuclear TVAandPNNLPerformedSurveillanceOfEstimatedTritium PermeationOverLast7CyclesofTPBARIrradiationfortheTritium ReadinessProgram.

- PermeationWasHigherthanOriginalDesignGoal,ButNoDesignorProduction FlawsHaveBeenIdentified.

Uncertaintybars represent90%

confidenceinterval

8/11/2014 4

TritiumPermeation Experience(2/2) 7 Nuclear OriginalFunctionalRequirementforTPBARTritiumPermeationinCycle6wasan Averageof1Ci/TPBAR/Year.

RadionuclideReleasestoEnvironmentatWBN1willbeManagedtoMeetNRC Requirementsin10CFRPart20and10CFRPart50AppendixI.

- ProposedManagementStrategyAssumesTPBARTritiumPermeationwillbe5.0 Ci/TPBAR/year.

ProjectedPathwayExposure(1/2) 8 Nuclear

• FSARChapter11RadiologicalConsequence AnalysesWillBeBasedon:

- ReleaseSourceTermBasedonNRCNUREG0017 MethodologytoCalculateanAverageMaximumHypothetical Release

- TPBARLoadingof1792TPBARs

- TPBARTritiumPermeationRateof5Curies/TPBAR/Year (BasedonConservativeUpperBoundofPlantData)

- UseofTVAQAComputerCodesGELCandQWATAto CalculateDosetoMaximumExposedOffsiteIndividual

8/11/2014 5

ProjectedPathwayExposure(2/2) 9 Nuclear

• ProjectedPathwayExposurestoMaximum HypotheticalIndividualRemainBelowNRCRegulatory LimitsforAllCases.

• ApplicableNRCRequirements(10CFRPart20and10 CFRPart50AppendixI)andTechnicalSpecifications WillBeMetforAllCases.

Pathways PreliminaryProjected Doses NRCLimit Liquid(Realistic) 0.75mremTotalBody 3mrem Liquid(Design) 0.81mremTotalBody Gaseous(Realistic) 1.29mremTotalBody 10mrem 10.86mremCriticalOrgan 15mrem Gaseous(Design) 1.29mremTotalBody 10mrem 11.34mremCriticalOrgan 15mrem PreliminaryResultsBasedon1700TPBARs PlantModifications(1/2) 10 Nuclear

• Additionof500,000GallonTritiatedWaterTank System

- IncreaseFlexibilitytoManageRCSFeedandBleed UnderContingencyScenariosandTimeEffluent ReleasestoEnvironment

- AllowsChangestoOperatingStrategyforRCSFeed andBleedtoKeepTritiumConcentrationsLowand SimplifyOccupationalExposureControls

- Implementedunder10CFR50.59

8/11/2014 6

PlantModifications(2/2) 11 Nuclear

• ReplaceCheckValvesUsedforThermalReliefon CCSandERCW SupplyLineswithReliefValves

- EliminatesPostLOCAManualOperatorActionsfor Isolation

• PreviouslyApprovedbyNRCinLicenseAmendment IssuedonMarch29,2004

- Eliminates40GPMSourceofUnboratedWater LeakageintoContainment(Assumedfor16Hours)

- Implementedunder10CFR50.59 PostLOCAShutdown MarginAnalysis(1/5) 12 Nuclear

• PostLOCAReactivityAnalysiswillBeConsistent withPreviouslyApprovedbyNRCforLicense Amendment77withtheFollowingKeyChanges:

- EliminationofDilutionofSumpWaterfrom40GPM UnboratedWaterInLeakage

- ReduceRequiredRCSBoronConcentrationbyIncreased IFBALoading

- ModificationofSimplifiedAssumptionsonTPBAR LithiumLeaching

• TimeDependentLeachingRateUsed

• PreliminaryResultsShowSufficientShutdown Marginfor1792TPBARs

8/11/2014 7

PostLOCAShutdown MarginAnalysis(2/5) 13 Nuclear

• XenonFreePostLOCA-RSACItem3.16B

Conclusion:

744ppmcorewith1792 TPBARs canaccommodatecycle variations PreLOCACb (ppm)

PostLOCACb (ppm)

Design Limit (ppm)

Margin (ppm)

HFP EQXECb =744ppm 1792TPBARs 644 1923.0 2135.3 212.3 PreliminaryResults PostLOCAShutdown MarginAnalysis(3/5) 14 Nuclear

• HotLegSwitchover-RSACItem3.16A

Conclusion:

1792TPBARcoreat744ppm withtimedependentleachratemeets requirements PreLOCACb (ppm)

PostLOCACb (ppm)

Design Limit (ppm)

Margin (ppm)

HFPEQXECb =744ppm 1792 TPBARs 644 1607.0 1736.5 129.5 PreliminaryResults

8/11/2014 8

PostLOCAShutdown MarginAnalysis(4/5) 15 Nuclear

• ColdLegRecirculation-RSACItem3.11B

Conclusion:

1792TPBARsat744ppm coremeetsrequirements.

PreLOCACb (ppm)

PostLOCACb (ppm)

Design Limit (ppm)

Margin (ppm)

HFPEQXECb =744ppm 1792TPBARs 644 1817.0 2041.2 224.2 PreliminaryResults PostLOCAShutdown MarginAnalysis(5/5) 16 Nuclear

• RefloodRecriticality-RSACItem3.11C

Conclusion:

1792TPBARcoreat744ppm withtimedependentleachratemeets requirements.

PreLOCACb (ppm)

Intermediate LBLOCA (Keff)

SmallLBLOCA (Keff)

HFPEQXECb =744ppm 1792TPBARs 644 0.976000 0.993956 PreliminaryResults

8/11/2014 9

LicensingActivities 17 Nuclear

• LicenseAmendmentRequesttoSupportTritium ProductionRequirements

- UpdateofPostLOCAReactivityAnalysisPreviously ApprovedbyNRCforLicenseAmendment77

- WouldIncludeDiscussionofExpectedEffluent Releases(UsingRealisticSourceTerm)andRadwaste SystemDesignandStationDose(UsingDesignBasis SourceTerm)for1792TPBARs TechnicalSpecificationChanges 18 Nuclear

• TechnicalSpecification(TS)ChangetoNew TPBARLimit

- ReviseTS4.2.1toReflectNewUpperLimitof1792 onTPBARLoading

- DeleteOutdatedTPBARInformationinSurveillance Requirements4.5.1.4and4.5.4.3

8/11/2014 10 LicensingActivitiesSchedule 19 Nuclear Closing 20 Nuclear

• TVAPlanstoSubmitaLicenseAmendment Requestfor1792TPBARsinJanuary2015

- SupportingAnalyseswillBoundOperating ExperiencewithTritiumPermeation

- SupportingAnalyseswillReflectPlantModifications MadetoIncreaseMargins

- AllRegulatoryRequirementsandPlantTechnical Specificationswillbemetwith1792TPBARCore Design

8/11/2014 11 Questions 21 Nuclear