Entergy - Waterford 3 Meetingwith NRC on Steam Generator

Batwing IssueSeptember 6, 2007

1

Introduction

* Nuclear Safety Priority- Conservative Operational Assessment- Defense in depth mitigation strategy- Conservative monitoring and action limits- Heightened awareness (ODMI)- Conservatively performing a mid-cycle

* Meeting Objectives- Inspection scope- Expected findings- Contingency criteria and planning

2

Agenda

Discussion Topic

Overview of BatwingMitigation Strategy

Presenter Time

Keith Nichols 5

Steam Generator MonitoringUpdate

Mid-Cycle Planned Activities

Mid-Cycle Contingencies andCriteria

Mid-Cycle CommunicationPlan

Keith Nichols 5

Rex Putnam

Rex Putnam

30

40

Bob Murillo 5

Summary and Q&A Joe Kowalewski 10

3

Overview of BatwingMitigation Strategy

Keith Nichols

4

SG 32 - Status

* 22 broken batwings in stay cavity region* Wrap Around Bar welds in the stay cavity region

have been inspected and reinforced except BW atColumn 84/85 (cold leg)

* Column 84/85 (cold leg) batwing slid into the tubebundle- held in place by tube friction- Adjacent tubes were plugged, sentinel plugged, or

plugged and stabilized

5

Waterford ý3 Steam Generator 32 Batwing Inspectionfrom Lower Handhole

Approximate Position ofHL Batwing with BrokenWeld (Columns 1081109)

Slotted Bar..

Approximate OriginalLocation of CL Batwingwith Broken Weld(Columns 84/85 Cold Leg)

44 '4 ~44~'.

44 44 44~ 44'~~4~444"444 4''.444444444

4444

Batwing Tube SupportBroken at Notch >i

Hot Leg

4 "<".44

j '44444 >44

44 ~444> ~'.

4' 4.4 '.. 444. 444

.'4444.

Approximate LocationRF13 Batwing Failures(Columns 82/83/84)

Cold Leg

~444 4 44 4

4444

K

~4~44

44 '"' ' 444>4

4444 r

4 4

Loose Batwing Bar

2 Batwings Brokenat Weld

.. 4•

44 9'. ".9~44~

~44 4

'44 44 4

444 44

Abrasive WearOn Top Support Plate

6

Refuel-14 Repairs

Defense-in-depth mitigation strategy- Analysis of potential loose parts

- Analysis and validation of tube wear rates

- Analysis of forces on welds for batwing to wrap around bar- Batwing welds to wrap around bar in SG 2 enhanced for batwings

that traverse through stay cavity- Inner row of tubes around stay cavity and loose batwing are plugged

and stabilized- Sentinel plugs added in on wrap around bar perimeter, around stay

cavity and around loose batwing

7

SG - 32 TUBE REPAIR HISTORYRF 13 AND RF14 - E,," 4Wate fford RF0.1 z ,,%T, 3 -. 1 C

L I - --* L C' N G S T A E. 1 - 1-1 -: :- R # 7 STAY PCSIT:ON

772P , c~ci 1 *c

:i3

'4l

•44

is.

Li

i

ilH

7-4

-777:7. 1: 7 .7-7,0 7- --. 7

.0 .. . .0 4 . . .. .0 . .

00070 704 -

4.4 77. .. ..

1,:ýH 1 1 L.-

22

.22

22

443

'I

.~1

'.2

A

4.2

2'.

22

~2

A

PA. fa I E S '.4s I ; I Vi l+'Q M Ile 1W. 100 ý I Sý Ai A S . -V r I

Preventive Plugging also in SG#1

Steam Generator MonitoringUpdate

Keith Nichols

9

SG Monitoring Update Summary

" Dedicated loose parts monitor installed to monitor SG- No metallic impacts identified

" Operational Decision Making Issue for primary tosecondary leak rate- 0.5 gpd steady and consistent with previous cycle- 2 gpd and 5 gpd triggers increased monitoring and evaluation- 5 gpd with a rate of 7.5 gpd/hr administrative shutdown- 15 gpd administrative shutdown

* High level of site awareness and sensitivity- Seven tube leak simulator training sessions this year with each

operating crew- Operations, Engineering and Chemistry monitoring

10

Steam Generator Primary to Secondary Leak Rate

3.00-

2.50

2.00 4

a.1.0

0

1.00

0.001/1/04 7/19/04 2/4/05 8/23/05 3/11/06 9/27/06 4/15/07 11/1/07

Date

11

Mid-Cycle Planned Activities

Rex Putnam

12

Mid-Cycle Inspection Purpose" Visually inspect the secondary side of the steam generators for the purpose

of:- determining any unforeseen extent of condition- determining any unforeseen change in the critical variables that were the basis for

the repair plan and operational assessment* Secondary inspections will confirm no unforeseen changes

- BW to Wrap Around Bar Interface [Weld, Clip, Deformation]- Examine Stay Cavity (Bottom Up) for Visible Deformation of the Tube Bundle- A BW segment extending beyond the Seventh Eggcrate Support- A BW segment outside of the stay cavity region

° Conservative Operational Assessment- RF14 Operational Assessment predicted margin for all mechanisms- Batwing related tube wear model was validated in RF14- Forces (and thus wear) attenuates as the batwing extends further into the tube

bundle- Open tubes would not be impacted until after the Sentinel plugged tubes- Sentinel plugged tubes remain intact- Active tubes are not expected to have significant wear for 16 years

13

Mid-Cycle InspectionsSecondary visual exam of upper batwings

° verify no upper batwing weld/clip failures in stay cavity area

* verify no gross deformation twisting of wrap around bar

Foreign object search and retrieval* remove accessible foreign objects

° no batwing segment outside of stay cavity

Secondary.visual inspection of stay cavity area* monitor batwing degradation

* verify that batwing at column 84/85 cold leg has not dropped

Secondary diagonal visual inspection of upper stay cavityarea (SG2 only)

* provide additional information in support of repair options inRF15

14

Upper Batwing Visual Inspection" Critical Variable: No additional batwings

have slipped into the tube bundle and nowrap around bar deformation

" Inspection: Visual exam to verify no upperweld failures for batwings in stay cavityarea and no gross deformation twisting ofwrap around bar

" Analysis: Wear growth rates and weardis trib ution.

15

FOSAR Inspection

e Critical Variable: No large mass foreignobjects

* Inspection: Foreign object search andretrieval and visual inspection

* Analysis:analysis j

Ginna tubeinvolved the

rupture eventrepeated impacts ofobject over severala large mass foreign

years.

16

FOSAR Inspection

9 Critical Variable: Effectiveness of stabilizer fencefor containing loose segments and maximumsize of loose batwing segments in stay cavity

0 Inspection: Visual exam of stay cavity region andFOSAR to verify no large batwing segments orsegments outside stay cavity

e Analysis: Broken batwing analyses assumedcontainment of BW segment in stay cavity regionto evaluate acceptability of tube impacts andwear, including normal and accident condition

17

Visual Inspection of Stay Cavity

* Critical Va riable: No extruded batwings0l1 nspection: Visual inspection of stay cavity

area for extruded BW segments9 Analysis: Loose parts analysis for impact

and wear. Note that attenuationanalysisis conservativelybased on a maximumforce determined by BW material plus sailarea.

18

450 Inspection

• Provide additional information for RF15repair options

* Inspection contingencies are developed

19

Expected Batwing Condition

* SG#1- Upper batwing welds should be intact.- Stay cavity damage has not been observed, but is possible. A

mitigation strategy similar to that used in SG2 was applied inSG1 in RF-14.

* SG#2- Upper batwing welds/clips and wrap around bar should be intact- Propagation of batwing damage in the stay cavity is expected- No indications of gross tube deformation is expected- Column 84/85 batwing may move but is not expected to damage

the stabilizer fence or active tubes- Stabilized tubes around the stay cavity may have visible through

wear but tube and stabilizer are expected to remain structurallyintact

- No gross tube damage is expected

20

Secondary InspectionTechniques

21

Wrap Around Bar InspectionTooling

* Access wrap around bar fromsteam drum

* Guide hooks on the wraparound bar

* Video probe inserts into guidetube for inspection

Wrap Around Bar InspectionResults

'C" ~

23

Lower Batwing Visual InspectionTooling

* Installs throughsecondary 4

handhole at • ....., .,...... ..... ... :• .•.}"..•! .. *. ....•

tubesheet/ •:~~~~.... ..•......•:.• .•....._.,.

18x fixed I.....'"-magnification K___________

24

Waterford 3 Steam Generator 32 Batwing Inspectionfrom Lower Handhole

Approximate Position ofHL Batwing with BrokenWeld (Columns 108/109) .,• • ,,•.:•• ...!. .

Slotted BarS•

Approximate OriginalLocation of CL Batwingwith Broken Weld(Columns 84/85 Cold Leg)

Batwing Tube SupportBroken at Notch 4.' 4... Approximate Location

RF13 Batwing Failures(Columns 82/83/84)

44.4.4~4.~

,.•. .•;•.•; .•j .... • •'-A'

Cold Leg

Loose Batwing Bar~ ..-4., . 44444'4~ 44.4.

..................44444~.444.".

~ .444~44*

44 ~ 44.44

4 '42 Batwings Broken

at Weld

N Abrasive Wear 25

On Top Support Plate

Area to be

examined whereBatwings enter

tube bundle(heavy line)

Cutaway of central stay cavity

26

First of a Kind Diagonal Inspection

0.66 SIR, 0.5.

0 -090' TYP

OT 1 0.09(r 1yý.......... VET PERODI

-.0 SI] TC

UPPER TUBE BUNDLESLUDGE LANCING(Flowstream Width = 0.48 in.)

27

Waterford Project Overview

* Diagonal Inspection Development MilestonesWestinghouse Letter LTR-NFSM-07-118 "Diagonal Inspection and April 07Mockup Requirements"Brooks Specification FS 55-05 "Diagonal Inspection Specification May 07Requirements"Mockup and Tooling Design June 07Mockup and Tooling Material Procurement June 07Lower and Upper Mockup and Tooling Fabrication July 07Video Probe and Tooling Prototype, Dry Mockup Testing August 07Video Probe and Tooling Prototype, Wet Mockup Testing August 07Video Probe and Tooling Final Design Development August 07Video Probe and Tooling Final Manufacturing and Testing September 07Video Probe and Tooling Qualification Testing September 07

* Mockup Tests were witnessed by Westinghouse andWaterford 3 personnel at Brooks

28

Mock-up of Upper Stay Cavity*Simulates the upper7

stay cavity region ...

* Limited draw backspace (21)

-- Jam

Uio -

29

Mock-up of Upper Stay Cavity450 Inspection

* This is a view ofthe mockup .showing the tubeto batwinginterface

Mockup test isunderwater in darkenvironment .

Guide tube is .40"thick in a .48 gap

Area of interest for 'diagonal inspection

30

Mock-up of Upper Stay Cavity

*Mock-up is in the tankand includes platformto closely representcorrect distance toentry point

17~A

~L4~ ~-~---

y.....................................................................~

I.

., ..

V 31

Mock-up of Upper Stay Cavity450 Inspection

Mockup photo fromvideo probe in wet and "dark environment450 inspection mock-up

testing was successful ,K ,- Able to see tube to

batwing interface- Able to see tube and

batwing degradation- Able to see 1-3 tubes

in bundle

Batwing to tubeinterface

32

Mid-Cycle Planned Activities Summary

* Secondary inspections (Upper, Lower andFOSAR) will verify that the criticalvariables used for the repair plan andoperational assessment are met

* 450 inspection mock-up testing has beensuccessful and will help establish RFI5repair plan

33

Mid-Cycle Contingencies andCriteria

Rex Putnam

34

Contingency Planning

* The potential outcomes of each secondaryinspection activity were evaluated

* Appropriate contingencies planning hasbeen taken

SA .comprehensive decision flow chart hasbeen prepared

* As found conditions will be evaluated andcontingencies implemented as necessary

35

Decision Matrix Purpose* Assures a consistent pre-thought decision for credible

secondary inspection outcomes for conditions thatcannot be accepted

- Reviews assure consistency with technical analyses- Used to establish level of contingency planning and resource

allocation" Assures a thorough communication of specific decisions

and criteria" Facilitates rigorous and timely decision-making during

the outage" Labeled decision blocks and actions have written

guidance explaining criteria and intended actionsColor coded for previously described contingency action

36

Mid-Cycle Outage Contingencies

* Decision chart contingencies are colorcoded for ease of use.- Eddy Current Test

- Install new 6" Access Port

- Batwing Weld Repair

- Batwing Stabilization

37

Wrap Around Bar InspectionContingencies (Chart I)

Weld/clip failures in stay cavity area* Indicated by irregular spacing and detached batwings

with separation to a weld remnant on the wrap aroundbar and comparison with as-left video from RF14.

* If batwing has migrated into the tube bundle,contingency is to bobbin test the open tubes on bothsides of the displaced batwing to locate it, then performPlus Point testing of tubes with identified wear

* If batwing is retrievable, contingency is to re-weld thebatwing to the diagonal bar using same repair plan usedin RF14

38

Wrap Around Bar InspectionContingencies (Chart I)

Gross deformation twisting of wrap aroundbar* Indicated by visible twisting deformation of the wrap around bar

and multiple nearby adjacent batwing cross-sections with a scuff,gouge or indentation indicating possible shroud impact. Damagewould be confirmed by comparison with as-left video from RF14.

* Contingency is to bobbin test 5 open tubes per column for 5columns on each side of the damage and Plus point identifiedwear. Develop and implement repair plan, such as a supportattached to the wrap around bar.

39

Diagonal Tube Bundle InspectionContingencies (Chart Ill)

Gross tube damage is identified° Indicated by irregular tube spacing, tube dislocation, through-

wall wear greater than one-third of the tube.

* Contingency is to bobbin test 5 open tubes per column closest tothe damage and plus point identified wear. If stabilized tube,evaluate and determine whether needed to deplug and stabilizenext tube in column to reinforce fence.

40

Gross Tube Damage

Gross tube damage that could compromisefence integrity* Tube spacing

* Force attenuation

41

Criteria For Gross Tube Damage (Assumes Failed Batwing)

Location Unacceptable Acceptable Comments

BW Penetration LessCavity Peripheral Tube Severed Than -1/3 of the way Severed Tube is Weakness in

Tube through the tube Defense Line

Penetrated By Batwing BW Penetration Less -1/3 of the way through theCavity Peripheral -1/3 of the way Than -1/3,of the way tube does not result in loss of

through the tube through the tube cable function.

Cavity Peripheral Total Through Tube

Tube-Double Sided section Wear greater Less Than -1/3 Through This value is the summation ofthan -1/3 of way total Tube Wear wear on both sides of the tube

through tube diameter

Interior Tube From Collapsed Or Visibly No visible.distortion Collapsed Tube w/o Cable isCavity Distorted Tube potentially unacceptable

Visible Thru Wall Tube Visible Thru Wall TubeInterior Tube From Wear greater than thatInterior Td Fm Wr aterantt .Wear less than that found Unexpected wear condition

Cavity found in adjacent in adjacent peripheral tubeperipheral tube 42

Criteria For Gross Batwing Induced Tube Prying Action (Assumes Failed Batwing)

Location Unacceptable Acceptable Comments

Tube Spacing 1/3 tube diameter criteria is developed fromgreater than -1/3 Tube Spacing less than 140 mil fluid force load displacement plus

Cavity tube diameter -1/3 tube diameter 116 mil original gap. Adjacent batwingsCaviy tbe dameer -/3 ube iamter must be examined to determine if tube

Peripheral between adjacent between adjacent tube expein ed t prying force

Tubes tube columns columns viewed along experienced significant prying forces or ifthe source of the abnormal spacing is due

viewed along batwing to plastic deformation of a worn adjacentbatwing batwing.

Tube! Unworn Tube/ Unworn batwing This equates to about 140 mil gap plus 116Cavity batwing gapPeripheral greater than -1.5 gap less than -1.5 times mil original gap. Nominal Tube to BatwingPperl gatier thikne -1 . thickness of nominal Clearance is 0.026 inch (0.013 inch on eachTube times thickness of batwing side).nominal batwing

Any Location Tube To Tube(Except Col Contact At See Above This indicates that large tube displacements84/85 in SG Vertical Tube are occurring in the SG.

32) Section

Distorted batwingobserved in This indicates that large tube displacements

Bundle innermost portion Undistorted batwingsLocation p are occurring in the SG.Loainof tube bundle 43

Foreign Object Search andRetrieval Contingencies (Chart IV)

* Large mass foreign objects are present* Indicated by visible large loose batwing segment

* Contingency is to evaluate and if needed remove the part andinstall a new 6" access port to retrieve using special tooling

* Loose part with new visible wear scar onan active tube" Indicated by visual scar on an active tube and comparison with

as-left video and eddy current inspection from RF14.* Contingency is to remove accessible parts and perform Plus

Point test of affected tube and surrounding open tubes todetermine depth of wear scar.

44

Stay Cavity InspectionContingencies (Chart II)

Gross tube deformation is identified0 Indicated by irregular tube spacing, tube dislocation, through-wall wear greater

than one-third of the tube.* Contingency is to bobbin test 5 open tubes per column closest to the damage

and plus point identified wear. If stabilized tube, evaluate and determine whetherneeded to deplug and stabilize next tube in column to reinforce fence.

* Batwing at column 84/85 cold leg has dropped° Indicated by visual extrusion beyond the 7th eggcrate and comparison with as-

left video from RF14.

* If above the ~6 th eggcrate, contingency is to ECT open adjacent tubes to locatethe displaced batwing and hydraulically expand selected tubes to capture andrestrain the batwing.

If below the "6 th eggcrate, contingency is to install a new 6" access port toretrieve using special tooling.

45

No Batwing MovementNo Action

46

.:Moderate. Batwing Movement.Batwi g Stabi ization

1 ~

F-on Fo.ces -e C~t rotte •Ot--g ony F-ee F-0 PF14 positio..As ce,-el o. grolty ,s bove p.vot pOor. ,•w-9 ShceS 01059 the contoctpoints c,'eoteO by pPtol egg-otes. D-e tore.-,gth toe I oter et', F botlctr-ests 0100 1ne 06 e~gc,orte 47

Large Batwin--Access P.ort to RE

48

,Io pment

* Substantially improved tooling has beendeveloped to facilitate contingency plans

* Batwing cutting tool is different frompreviously discussed- Diamond wire mockup tests were

unsuccessful- Versatile hydraulic tool developed

49

:-.tri e\

.,.ml

Delivery tool willhave -150°range of motion

Multiple endeffectors can beused with thisdelivery tool

*1.~i.

V I

4

:1.1

I

Ii A{

Air Gripper jf

I £j .1;:1 1

...•::...:;••,.,;••

50

Batwing GuttirngT.. ;."•... . A.. . • • :..Solin

.1 i• , ' ..'. .

• • ;.. .• • ,},

StayCav43ty Mbcku2p

S .. 7,

. ...•!:.::.:& .i,.. ..••.•. . ' . :....•i.••• . ,....•: . .. :/• -. ,!

• . . , ..:... I! v ' .;• " " " : " •

,•:: ... ii •:: : ::, " •° !:I : i • ; • .•;

;a i t ...

; .. .. • • • ::L ,•, . .•. wit ..:::• : •

t

K.. I

.... 4,••, 51

Access Hoe Cons~t~raints~

This image is ofthe handholeshowing thetubelane with thecenter tie rods inplace

The center tierods sleeves are1.125" and thetubelane is 4.25",leaving 1.56" oneither side

I

52

0!•:;• k• ,..'. ! L .".. .

/I &-%I 1 -up Lower•: •"i•'• :. ; • ..•. ,/.• •.:, : ..:. •• f• @ i• .

Model showing the center stay area with stay capand blow down

Center tie

rods Stay cap

Blow down

pipe

53

Mid-Cycle Contingencies andCriteria Summary

* Secondary inspections (Upper, Lower andFOSAR) will verify that the criticalvariables used for the repair plan andoperational assessment are met

* The potential outcomes of each secondaryinspection activity have been evaluatedand appropriate contingencies planninghas been taken

* A comprehensive decision flow chart hasbeen prepared 54

Mid-Cycle CommunicationPlan

Bob Murillo

55

SG Mid-Cycle Communication Plan

" Licensing Manager will be focal point forcommunications with NRC

" Pre-established communication plan- NRR and Region IV management points of contact

* NRC Resident Inspector will be briefed dailyTeleconference with NRR/Region IV, as needed- Review of inspection results- Review of contingency decision making- Expansion of inspection scope- Finding of unexpected results

NRC requested photographs or video media will bemade available via Licensing Manager

56

Summary and Q&A

Joe Kowalewski

57

Conclusions* Continued focus on safe operation* Continued conservative approach to evaluation and mitigation of

batwing condition utilizing defense in depth strategy" Continue the operational monitoring, heightened awareness and

conservative action limits° Visual inspections planned for the mid-cycle outage will identify any

unforeseen extent of condition or unforeseen change in the criticalvariables that were the basis for the repair plan and operationalassessment

" Appropriate contingency actions are planned with pre-determineddecision criteria to facilitate decision making for any unexpectedfindings.

* Communication strategy is in place for prompt information exchange

58