NUCLEAR FUELPERFORMANCE

Office of Nuclear Regulatory ResearchOffice of Nuclear Reactor Regulation

February 24, 2005

ACRONYM

* ALARA* BWR* CFR* GDC* ISG* LTA* LOCA* PWR* RCS* RIA* SRP* UFSAR

As low as reasonably achievableBoiling-water reactorCode of Federal Regulations10 CFR Part 50, Appendix A General Design CriterionInterim Staff GuidanceLead Test AssemblyLoss-of-Coolant AccidentPressurized-water reactorReactor Coolant SystemReactivity Initiated AccidentStandard Review Plan (NUREG-0800)Updated Final Safety Analysis Report

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00w AGENDA

* Activities on Fuel Behavior, Office ofNuclear Regulatory Research (RES)- Dr. Farouk Eltawila

* Oversight and Guidance, Office of NuclearReactor Regulation (NRR)- Frank Akstulewicz

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ACTIVITIES ON FUELBEHAVIOR

Dr. Farouk EltawilaOffice of Nuclear Regulatory

Research

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FUNCTIONS OF FUEL RODCLADDING

Often considered to be the firstbarrier for retention of fissionproducts

Provides structural integrity toensure coolable core geometry

Gap-* PWR Fuel Pelletswith Dished Ends

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FUEL PELLETS RETAIN MOST FISSIONPRODUCTS AT OPERATING

TEMPERATURES

U02 fuel pellets consist of crystallinegrains with porosity

Fission products can be trapped inthe pores and within the grains.

Only a few percent of the volatilefission products are released fromthe pellets during normal operation.

Temperatures near core melt areneeded to get large releases of fissionproducts trapped in the UO2 pellets.

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420RESEARCH FOCUSED ON

POTENTIALLY RISK-SIGNIFICANT REACTOR EVENTS

Significant fission products occur onlywhen temperature approaches fuelmelting.

Only two ways to melt fuel:

1. Too much power: ReactivityInsertion Accident (RIA)

2. Not enough cooling: Loss ofcoolant accident (LOCA)

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e stREGULATORY CRITERIA FOR1AJ REACTIVITY-INITIATED

ACCIDENTS (RIAs)Test FK-9 Regulatory limit developed in 1974 with data on fresh andTop Ldvlpdwt rs

low-burnup fuel (Reg. Guide 1.77).

Tests in early 1990s (France and Japan) showed largeeffect of burnup from cladding corrosion.

Research Information Letter (No. 0401) provided anU-.

assessment of RIAs in operating reactors based on recentdata for high-burnup fuel.

RES currently assisting NRR with review of industrysubmittal on this subject.

90, 0RBottom Regulatory Guide 1.77 to be revised.

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REGULATORY CRITERIA FORLOSS-OF-COOLANTACCIDENTS (LOCAs)

Regulatory limits (10 CFR 50.46(b)) on cladding temperatureand oxidation developed in 1973 based on data fromunirradiated Zircaloy tubes.

Burnup effects and alloy effects are expected based oncurrent understanding.

Major research effort is underway at Argonne by NRC withindustry cooperation. Laboratories in other countries arealso investigating.

Technical basis for performance-based cladding criteria istargeted for September, 2005.

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*ARG1 ANALYTICAL CAPABILITYAd5 FOR HIGH-BURNUP FUEL

Calculations needed for NRRreviews (fuel temperature, rodpressure, fission gas release, andvendor code audits).

Calculations needed to plan testsand understand results.

NRC's fuel rod computer codes,FRAPCON and FRAPTRAN, areupdated for new cladding alloys,higher burnups, and other newconditions

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OVERSIGHT ANDGUIDANCE

Frank AkstulewiczOffice of Nuclear Reactor Regulation

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REQUIREMENTS FORDESIGN BASIS ACCIDENTS

* Technical Specifications limit coolantactivity- Maintain design basis accident site boundary

dose consequences per 10 CFR 50.67Maintain design basis accident control roomdose. consequences per GDC1 9

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4.

,RREGAL RE G ULATO RY

X REQUIREMENTS FORt*< PLANT OPERATION

Radiation Protection Programs have beendeveloped to achieve occupational and publicdoses as low as reasonable achievable (ALARA)- Licensees comply with occupational and public

exposure limits per 10 CFR Part 20- Licensees perform offsite dose projections and

control gaseous and liquid effluent systems to satisfyALARA design objectives per 1 0 CFR Part 50Appendix I

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CURRENT FUELRELIABILITY STATISTICS

Current Statistics PWR BWR

Number of Plants 68 35

Number of Fuel Rods with Defects 22 9Number of Plants with Fuel Defects 14 8

% of Plants with Fuel Rod Failures 21 % 23%

Estimated fuel rod defect rate 6.7 4.3(failed rods per million)

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<oe~~oNRR OVERSIGHT ANDGUIDANCE

* Meet periodically with fuel vendors* Review and approve fuel design changes.

- Establish limits on fuel duty, oxidation, andburnupEncourage Lead Test Assemblies (LTAs)Require mechanical and thermal/hydraulictesting

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q CONCLUSIONS

* Radioactive control programs ensureoccupational and public exposure ismaintained ALARA.

* Staff continues to monitor fuelperformance

* Staff reviews fuel design changes* Staff and industry oversight continue to

maintain high fuel reliability* Important role of defense-in-depth

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4 I . I

NUCLEAR FUELPERFORMANCE

INTRODUCTION I OVERVIEW

Joe SheppardPresident & CEO, STPNOC

Chairman, FRP Executive Committee

OUTLINE

* Materials Initiative Overview

* Fuel Reliability Program

* Fuel Performance Trends

* Industry Focus Areas

* Overall Impact and Assessment

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ACRONYMSAOA -APSR-CNO -EPRI -FMEA-FRED -

FRP -GWe -MRP -NDE -NEI -PCI -SGMP-

Axial offset anomalyAxial Power Shaping RodsChief Nuclear OfficerElectric Power Research InstituteFailure Modes and Effects AnalysisFuel Reliability Data BaseFuel Reliability ProgramGigawatt electricPWR Materials Reliability ProgramNondestructive ExaminationNuclear Energy InstitutePellet-Clad InteractionSteam Generator Management Program

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MATERIALS INITIATIVEOVERVIEW

* In 2003, industry recognized need forunited effort on materials issues

° CNOs endorsed NEI 03-08

* > $59.5M industry-sponsored R&D$1 OM for EPRI FRP

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INITIATIVE (cont'd)

* Purpose is to provide

Consistent management process

-Materials issues prioritization

- Proactive, integrated, coordinatedapproaches-Implementation oversight

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INITIATIVE (cont'd)

X NEI 03-08 committed licensees to- Fund materials programs

Supply talent-Act in united manner

* Management structure created

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NEI 03-08 STRUCTURE

Nuclear Strategic Issues Advisory Committee(All CNOs)

| Materials Executive Oversight Groupl(Selected CNOs)

I IMaterials Technical Advisory Group

(Issue Program Chairs, etc.)

Issue Programs (MRP, SGMP, etc.), Owners Groups,Fuel Reliability Program

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ISSUE PROGRAMS

* BWR Vessel & Internals Program

* PWR Materials Reliability Program

* Steam Generator ManagementProgram

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PROGRAMS (cont'd)

* Fuel Reliability Program

* NSSS Owners Groups (materialsprograms)

* Chemistry, Corrosion, NDE

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FUEL RELIABILITY PROGRAM

* 1998 - Robust Fuel Program focused onfuel design and performance

* 2003 - Fuel Reliability Programrefocused on fuel reliability to supportMaterials Initiative

* Ob ective is highly reliable fuel withzero defects

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FRP (cont'd)

* Four specific focus areas- Root cause investigations of

failures-BWR crud and water chemistryPWR crud and water chemistryRegulatory interface

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FUEL PERFORMANCE TRENDS

* Several US plants still experiencingfuel defects

* Number of assemblies with fueldefects declined in 2004

* Objective is highly reliable fuel withzero defects

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Fuel ReliabilityPercentage of Units Reporting Zero Defects

10090

8070

8583 83 84

76 77 787471

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1989 1991 1993 1995 1997 1999 2000 2001 2002 2003 2004

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2004 FAILURE MECHANISMS

BWR - PCI/suspect 7- Debris

- Unknown/not inspected35

PWR - Fretting 22- Unknown/not inspected 13

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* FRED now contains complete fuelperformance and failure trends

* All US nuclear plants will have accessto facilitate mandatory data entry

* International FRP members in Feb 2005

* Access for fuel vendors in 2005 Q1

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INDUSTRY FOCUS AREAS

* Manufacturing techniques, design

* Materials

* Duty

* Water chemistry

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FMEAJ Consequences

AOA GuidelinesUT CleaningBOA Code

Results

PoolsideHot CellCrud ScrapesChemical Analysis

InitiatingConditions

FRP ScopePartial FRP Scope

Operational GuidelinesT/H Models & PWR Dist

Models 10CFR50Vendor ScopeChemistryGuidelines

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OVERALL IMPACTAND ASSESSMENT

* FRP and industry efforts are starting tohave positive effect on overall reliability

Most fuel defects represent a very smallfraction of limits that could affect offsitedoses

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ASSESSMENT (cont'd)

* Licensees and vendors are takingaggressive action to correct issues

* Fuel defects cause operational issuesand'have economic consequences

* Overall objective is highly reliable fuelthat operates defect free

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FUEL RELIABILITY PROGRAM

Rosa YangTechnical Executive - EPRI

INTRODUCTION

* EPRI provides technical expertise,project management for FRP

* EPRI focus is R&D to support FRPobjectives

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FUEL DEFECT INVESTIGATIONS

e Key aspects

Confirm performance margins- Support fuel defect root cause

investigations

* Performed in cooperation with licenseeand fuel vendor

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INVESTIGATIONS (cont'd)

* Focus on poolside inspections and hotcell examinations

X Plant performance results entered inFRED

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HOT CELL INVESTIGATIONS

* Most definitive, but most costly andtime consuming

* Can provide very illuminating results

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BWR PCI FAILURE

Short Axial Crack Metallographic Cross Section atShort Axial Crack

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POOLSIDE EXAMINATIONS

e Faster; less expensive; can beperformed more frequently than hotcell investigations

* EPRI developing better poolsidetechniques; early results arepromising

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CRUD CROSS SECTIONS

Steam chimney onwater side

Crystals containingSi, Zn, Al on fuel

~ side near failure

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SUM MARY

* Only a brief snapshot of some EPRIactivities

* Projects yielding results; performanceimproving

* Close licensee and vendor involvementhas been critical to success

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FUEL VENDOR'S PERSPECTIVE

John MathesonSenior VP, Nuclear Fuel - AREVA

FUEL VENDOR'S PERSPECTIVE

Jack FullerCEO - Global Nuclear Fuels

FUEL VENDOR'S PERSPECTIVE

Mike SaundersSenior VP, Nuclear Fuel - Westinghouse

LICENSEE'S PERSPECTIVE

Jim MaloneVP, Nuclear Fuels -

Exelon Generation Company, LLC

PROBLEM STATEMENT

We experienced an unacceptablenumber of fuel defects in Exelonunits. Although Exelon performanceis consistent with industry trends inthe past three years, our goal is zerodefects.

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Fuel ReliabilityPercentage of Units Reporting Zero Defects

100 -90 -80-70 -

8583 83 84

76 77 A 78'471

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1989 1991 1993 1995 1997 1999 2000 2001 2002 2003 2004

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2004 FUEL FAILURE MODES

Braidwood - flaw assisted PCI

Dresden - foreign material or PCI

LaSalle - foreign material and flawassisted PCI

Limerick - undetermined

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FAILURE MODES (cont'd)

Quad Cities 1 - 2 PCI, 1 undetermined

Quad Cities 2- PCI

Three Mile - likely PCI

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ACTIONS TAKEN

e LaSalle 1 &2 - removed leaking fuel

* Placed previous fuel design in lowduty locations

* Quad Cities 1 - replaced 233 fuelassemblies susceptible to failure

* Instituted ramp rate controls

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ACTIONS (cont'd)

* Performed hot cell investigation ofLaSalle failures

* Employed conservative managementof BWR defects

* Strengthened vendor oversight

* Increased involvement with industry

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FUEL DEFECT IMPACTS

* Dose increases not significant

* No significant changes in radiationlevels

Surveillances continued on schedule- Maintenance conducted per template

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IMPACTS (cont'd)

* Sites met or exceeded onlinecorrective maintenance goals

* Utilized FRP results to support dosereduction efforts-Zinc addition-Ultrasonic fuel cleaning

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SU MMARY

* Fuel defects are unacceptable

* Actively managed defects andvigorously pursued root cause

* Dose increase not significant

* No delays or elimination of anysurveillances or maintenance

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