ML063210266

11/16/2006 Meeting Slides with the Palo Verde Nuclear Generating Station Licensee Nuclear Fuel Management Activities

ML063210266
Person / Time
Site:	Palo Verde
Issue date:	11/16/2006
From:	Office of Nuclear Reactor Regulation
To:
Wilkins, L E, NRR/DORL/LPL4, 415-1377
Shared Package
ML063210258	List: ML063210266 ML063230011
References
Download: ML063210266 (40)

Text

P A L O V E R D E 1 Nuclear Fuel Update Palo Verde Nuclear Generating StationNovember 16, 2006Meeting with US NRC P A L O V E R D E 2 Nuclear Fuel ManagementMichael E. Powell, DR Nuclear Fuel ManagementKevin Graham, DLNuclear Fuel ServicesJohn Hazelbaker, MGR NFM ProcurementRobert Bandera, DLNuclear Fuel Analysis Kathleen C. Parrish, TMANuclear Fuel ManagementYovan Lukic, Principal Engr. Nuclear Fuel ManagementBurton A. Grabo, PANuclear Fuel ManagementJeffrey S. Schmidt, SL Nuclear AnalysisCraig A. Hasson, SL Transient AnalysisThomas C. Cannon, SLReload AnalysisVacant SLReactor EngineeringBrian J. Hansen, SL Dry Cask StorageRick L. Huffman, SLFuel Services P A L O V E R D E 3 Review of 2005-2006December 2004 Meeting with NRRSG Replacement & Power UprateDry Cask Storage SuccessesSIMULATE ImplementationAugmented AORsNew Top Grid DesignNew CEAs & LFA Projects P A L O V E R D E 4 Agenda TodayCEA ReplacementDual LFA ProgramFuel PerformanceDry Cask Storage UpdatePlanned License Submittals P A L O V E R D E 5 CEA Replacement P A L O V E R D E 6Review of CEA HistoryFelt Metal Wrapped Pellets in TipsCEA Clad Failures Observed -2001

-Cracks in High Fluence CEA Tips

-Root Cause -IASCC, Inadequate TestingAll Full Length CEAs Replaced

-Replaced with Small Pellet DesignLifetime Software Abandoned P A L O V E R D E 7Determination of New LifetimeInspection versus ReplacementMonitored YGN Inspections

• 5 Cycle Lifetime:

-Vendor Adjusted Software

-Inconel IASCC ThresholdNeed New CEAs for Fall 2008 P A L O V E R D E 8 Design of Future CEAsWant: -Industry Standard AgInCd

-Extended Tip RegionCEDM Weight Restrictions

-AgInCd Tip Region

-Boron Carbide for RemainderLifetime-~20 EFPY Design Lifetime

-~12 EFPY Experience Base (Hot Cell)

-~18 EFPY Experience Base (PIE)

P A L O V E R D E 9 Analysis & Licensing ImpactsAgInCd Tip 75% Worth (vs. 90%) of B4CCEA Misoperation Events BoundedScram Reactivity Curves Have MarginLOF & SS/SR Being ReanalyzedTech Spec 4.2.2 Needs Revision P A L O V E R D E 10 Dual LFA Program P A L O V E R D E 11 Specific Fuel Design GoalsMaterials for Higher Burnup/Duty

-Cladding Oxidation

-Dimensional StabilityPreserving/Increasing Operating Margins

-Minimize CRUD

-Increase Thermal MarginImprove Fuel UtilizationOverall Robust Design for Flawless Fuel P A L O V E R D E 12 Lead Fuel Assembly ProgramFuel Contract TimelineLFAs Needed to Demonstrate New Design

-Observe Performance in Both PV Duty Cycles

-8 Assembly, 3 Fuel Cycle LFA ProgramsAREVA and Westinghouse Designs

-M5 (AREVA) and Optimized Zirlo (WEC)

-"Mixing Vane" Grids and IFMs in Spans 8 & 9

-Gadolinia (AREVA) and IFBA or Gd (WEC) BAs P A L O V E R D E 13 Analysis & Licensing StrategyExplicitly Model LFAs in Core Physics ModelMaintain Within > 5% of Limiting AssemblyRod Burnup Will Remain < 60,000 MWD/TVendors Perform Mechanical, Thermal Hydraulic & LOCA Analyses

-AREVA to Assure Non-Limiting

-WEC to Assure CompatibilityAPS Performs Standard Reload Safety Analyses P A L O V E R D E 14 Analysis & Licensing Strategy(continued)Safety Limits Preserved by Maintaining LFAs non-LimitingTransient Analyses Explicitly ValidatedCOLSS & CPC Setpoints Explicitly Calculated10CFR50.46 Exemption for M5 Required

-Expect Exemption for Optimized ZirloEvaluating Need for Tech Spec Changes P A L O V E R D E 154.2.1Fuel AssembliesFuel assemblies shall be li mited to those fuel designs that have been analyzed with applicable NRC staff approved codes and methods and shown by tests or analyses to comply with all fuel safety design basesA limited number of lead test assemblies that have not completed representative testing may be

placed in non-limit ing core regionsOther cladding material may be used with an approved exemption.

P A L O V E R D E 16 2.0 SAFETY LIMITS (SLs)2.1.1.1In MODES 1 and 2, Departure from Nucleate Boiling Rati o (DNBR) shall be maintained at > 1.34.2.1.1.2In MODES 1 and 2, the peak fuel centerline temperature shall be maintained <

5080°F (decreasing by 58°F per 10,000 MWD/MTU for burnup and adjusting for burnable poisons per CENPD-382-P-A).

P A L O V E R D E 17 Palo Verde Fuel Performance P A L O V E R D E 18Fuel Clad Performance Clad Performance in Uprate Conditions High Burnup Fuel Performance P A L O V E R D E 19 Clad Performance in Uprate Conditions3% Power and ~4 o F Inlet TemperatureNew Steam GeneratorsIncreased Clad OxidationIncreased Steaming Rates

-Each 1 oF or 1% Power is Worth 10% Steaming Rate

-Higher Source Term from New Steam Generators

-CRUD & AOA Risk P A L O V E R D E 20 Integrated Clad Performance StrategyAdvanced Clad AlloyPrimary ChemistryCRUD and Oxide SoftwareThree Enrichment Lattice DesignsLong Range Fuel Inspection Plan P A L O V E R D E 21 The Two Duty CyclesTypical (U2C13) Core Design Fresh 1x burned 2x burned Reinserts P A L O V E R D E 22 ZIRLO TM CladWestinghouse Low Tin Zirconium Based AlloyProtect High Duty 2 Cycle Assemblies

-First Implementation in Unit 2 Cycle 11Licensing Limitations

-Fuel Duty Index & Maximum Oxide Thickness

-Vendor Oxide Software for Core Design Assessment2R11, 2R12 & 2R13 Inspection Results

-Performance as Expected P A L O V E R D E 23 3 Enrichment Lattice DesignProtect High Duty First Burn Assemblies

-First Implementation in Unit 2 Cycle 12Design Concept -Balance Power & Flow

-In-House Designed Based on APS CRUD Model

-Three Enrichments, Four Pin TypesInspection Results

-2R12 -No CRUD

-2R13 -Threshold CRUD P A L O V E R D E 24 Sample Lattice Comparison4.05 w/o3.75 w/o3.75 w/o ErPrevious -64 ErNew -64 Er4.29 w/o3.79 w/o Er3.79 w/o3.99 w/o P A L O V E R D E 256.952.581.250.5 0 1 2 3 4 5 6 7Average Crud Thickness in Worst Lumped Channel (microns)U2C9U3C9U2C11U2C12Unit and CycleComparison of Average Crud Thickness - PredictedNew Lattice Design, Curren t Source Term P A L O V E R D E 26High Burnup Fuel Performance High Burnup Fuel Failure TrendLoose Top Grid Cells Top Grid Re-Design P A L O V E R D E 27 Flawless FuelNew Agreement with Westinghouse

-IdentifyandInvestigate All Failures

-Incentive for Flawless Fuel

-Reconstitute Failed AssembliesSipping in Containment UT in Spent Fuel Pool P A L O V E R D E 28High Burnup Fuel Failure TrendMid 90's, Clean Cor es Cycle After CycleTen Failed First Burn Pins in U2C9One Failed End Cap Weld (U1C9)Nine Indications Starting with U2C9Five of Nine Cycles with 1 or 2 IndicationsThree Identified Grid-Rod Fretting FailuresNo Current Operating Failures P A L O V E R D E 29 Loose Top Grid CellsPV1P Fabrication CampaignRoot Causes

-Bias in Grid Constr uction Tolerances

-Force-Fit of 20 mil O versize Guide Tube

-Rod Pushing Table Mis-Alignment

-Weaknesses in Inspection/QA Process P A L O V E R D E 30 Top Grid Re-DesignZirc-4 to Inconel 625Wavy strip to Straight StripCantilever Spring Cut-outDouble Back-up ArchAccommodation of Expanded Guide TubeGrid to Guide Tube AttachmentChange to "Top Nozzle" (UEF)

P A L O V E R D E 31 Dry Fuel Storage UpdateISFSI in Production 4 Years47 Casks on the PadsDoses Consistently Under 50 mRNeed NAC Amendment #5 12/07 P A L O V E R D E 32 Planned License Submittals P A L O V E R D E 33 Planned License SubmittalsTS 3.1.6 Shutdown CEA Insertion Limits (2006)TS 5.6.5 Core Operating Limits Report (Summer 2007)10CFR50.46 Exemption for M5 (Summer 2007)TS 2.1.1 Fuel Safety Limits (Summer 2007)TS 4.2.2 CEA Design (Fall 2007)Revised Inlet Flow Uncertainties (Fall 2007)Potential CEA Ejection with RAVE Methodology (2008)

P A L O V E R D E 34Shutdown CEA Insertion LimitsCurrent T.S. Allows Insertion to 144.75" WithdrawnSafety Analysis Only Covers Insertion to 147.75"

-Sufficient Additional Shutdown Margin Verified

-Guide Tube Wear Program Controlled to 147.75"Shutdown Margin is Monito red per Core Data Book T.S. 3.1.6 rewritten to 147.75" withdrawnSubmitted to NRC Summer 2006 (Requested 6/07)

P A L O V E R D E 35 Core Operating Limits ReportInconsistent CEA Drop ReferenceCurrently Processing Changes

-Remove CESSAR References

-Add 3990 MW Power Uprate References

-Add Topical Report of 2 ndTier ReferencesExpected Submittal Date: Summer 2007 P A L O V E R D E 36M5 Clad ExemptionFall 2008 Insertion of AREVA LFAsM5 Already in Use M5 Not Listed in 10CFR50.46Expected Submittal Date: Summer 2007 P A L O V E R D E 37TS 2.1.1 Safety LimitsPotential TS Submittal to Allow for LFAs TS 2.1.1.1 DNBR

-Allow for Alternate CHF CorrelationTS 2.1.1.2 Centerline Melt Temperature

-Allow for Alternate Burnable AbsorbersPotential Submittal Date: Summer 2007 P A L O V E R D E 38 TS 4.2.2 CEA DesignTech Spec 4.2.2 states:

"The control section for the full strength CEAs shall be boron carbide with Inconel Alloy 625 cladding"Needs to include AgInCdExpected Submittal Date: Fall 2007 P A L O V E R D E 39 Revised Inlet Flow UncertaintiesPV DNBR Limit Allows Statistical Combination of Inlet Flow Distribution Uncertainties

-Within DNBR Limit or via Deterministic PenaltiesRe-Analysis of Experimental Data

-Reduced Uncertainties

-Reduced DNBR PenaltiesPotential Submittal Date: Fall 2007 P A L O V E R D E 40 CEA Ejection with RAVECurrent CEA Ejection AOR Precludes Fresh Fuel Under Lead BankConsidering RAVE Analysis

-Core Design Flexibility

-Improves Worth for Axial Control

-Margin for New CriteriaPotential Submittal Date: 2008