BVY 04-113, Vermont Yankee Nuclear Power Station - Proposed Technical Specification Change No. 263 - Supplement No. 20 Extended Power Uprate - Meeting on Steam Dryer Analysis Meeting Presentation Slides

Vermont Yankee Nuclear Power Station - Proposed Technical Specification Change No. 263 - Supplement No. 20 Extended Power Uprate - Meeting on Steam Dryer Analysis Meeting Presentation Slides

ML042890417
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	09/29/2004
From:	Entergy Nuclear Northeast
To:	Office of Nuclear Reactor Regulation
References
BVY 04-113
Download: ML042890417 (100)

Text

{{#Wiki_filter:BVY 04-113 Docket No. 50-271 l-V Z A1~ Attachment 2 Vermont Yankee Nuclear Power Station Proposed Technical Specification Change No. 263 - Supplement No. 20 Extended Power Uprate - Meeting on Steam Dryer Analysis Meeting Presentation Slides NON-PRORIETARY Total number of pages in Attachment 2 (excluding this cover sheet) is 99.

~Etergy Entergy V U

Power Uprate Project Steam Dryer Updated Analysis Presentation September 29, 2004 Entergy, GE, SIA, CDI, Fluent 1

--%w-%,-Entezr,, Brief Synopsis - Vermont - U Yankee Power Uprate

     *December 2001 . Start Project
     *September 2003, - Submittal
     *Extensive Ana lyses! Review
     *Extensive Plant Modifications
     )Operate Safely and Efficiently Now and in the Future 2

-En teqrgy Key Principles

• Reasonable assurance that VY shall operate safely and efficiently at uprated conditions
• VY Steam Dryer shall perform well at EPU and shall NOT challenge system functions important to safety 3

--=Etergy Industry Operating Experience

• Multiple failures at Quad Cities

   * 'Conventional Wisdom' significantly challenged
   *Critical differences exist between plants
    >Major evolution of GE methodology
    >Plant-specificapproach needed 4

-Entergy Methodologies

• GE Methodology

  *Generic Load Definition
  *Response Spectrum Analysis
  *Finite Element Model
*Plant-specific Approach
  *Plant Specific Data
   *Acoustic Circuit Model
   *Vortex Shedding CFD Model 5

A% Entggyr Key Safety and Reliability -4 Principles Requirements

• Plant-specific approach to Steam Dryer Issue

      *Deliberate, controlled, rigorous power ascension with plateaus
      *Rigorous inspection plan: "8 months of EPU Operation
      *Closely follow industry initiatives 6

-=Entergy Presentation Overview

• Open session

   *VY dryer analysis changes summary:
      - Plant-specific load definition

• Updated VY dryer analysis results

   *Vortex Shedding investigation
   *Results and comparisons
   *Power-Ascension/ Dryer monitoring plan summary 7

-Entergy Presentation Overview (cont.)

• Closed session
• Detailed presentations:

      + VY acoustic loads analysis

• VY plant specific load definition
• Comparison VY FIV measurements
• Dryer power ascension monitoring plan 8

      - Etergy IUrn1 --    Dryer Analysis Changes Summary mVY plant-specifi C load definition

• Acoustic Model Developed (CDI)
• Plant Specific Main Steam Instrument Data Obtained
• Data converted to Main Steam Pressures
• Dryer Load Definition created
• GE Response Spectrum Developed
• GE Finite Element Model Run
• Results 9

1116-,-

              -EntcygT '"--L Dryer Analysis Changes Summary                                                  (cont)

VY plant specific load definition I-VY CDI aTP -VYN SCD EU GE RS~EvebpeVYNPSERJ I U) I..

2) ___ _ _ ___ _ _ _ _ _ _ _ _ _ _ ___ ___ _

L. Fq Frequecy( Hz yH 10 I Preliminary Information I

  -Entergy Dryer Analysis Changes Summa ry                 (cont)

• Analysis stress results:
• All dryer components evaluated in finite element analysis at EPU were less than fatigue stress criteria l Preliminary Information l

  -Entergy

-1 Vortex Shedding Investigation

   *Question on impact/role of vortex shedding
   *CFD Model developed of VY Vessel/Dryer (Fluent)

Industry accepted methodology

• New application Initial results

       *Low Frequency loads Consistent with acoustic model frequencies 12

r-En tergy -I VY FIV Comparison

    *Strain Gauge Data VY vs. QC(OLTP) mPiping Vibration Levels 13

I

             -Entergy

---

7 VY FIV Comparison Et VY vs. QC2 100% OLTP Strain Measurements Sample Rate, sVs* 1024 Spectral Plot Daft: 11'Aug2004 Samaple Rate, sps = 1024 Spectral Plot Dae 3Ar2O Tine Duration, sec 120 VY - 100% PI, Dryweff Sttaf n/Press. Ch 33 Composite prrrsi

• 0.4356 Tinie Duration. see 167 Ouaed Clttes-2Z 4/212004, 800MWe. Ch 34 Composite, ptrmisi 0.80839 I I I Al Notch FilterOn I I I I 0.35 mm m urn .*. =*4 - U - U - U 0.07 1.1 I I I I I 0.06 VY maximum I

I I II I I I I I 0.3 I - I - T- - - I- - - - -I - - I I I I I I 0.25 0.05 -I- I I I I I I E I I I I I I I I I I I I I I I I I I Z0.2 axim um-- Yi-10.04 I I I I I I e won 'a wm I Ima m I w I I I I I ZU I I I I I Us I I I I I I 0.15 0.03 *1 I I - I I I - I I I I I I I I I I I I- - - -I-I I I I I I I I L1..... 0.02 I I 0.01 50 100 1SO 200 250 300 20 40 60 80 100 120 14 100 100 200 Frequency. Hz Frequency, 1ft Vermont Yankee Quad Cities Unit 2 14 I Preliminary Information I

INWRNNNIw tergy VY FIV Comparison -ml EPU Maximum Measured Acceleration EPU Maximum Measured Acceleration 1.400 1.200 1.000 E 0.800 Z 0.600-0.400 0.000 Dresden Unit 3 Quad Cities Unit 1 Brunswick Unit I Plant 15 I Preliminary Information I

Dryer FIV Monitoring Plan Summary . Objective Ensure dryer integrity during gradual power increase

• Approach
• Take plant data at 2.5% power increments

                        ,v

• Hold at 5% incremental power levels for 7 days (minimum)
• Compare data to acceptance criteria
• Moisture carryover monitoring (daily)
• Dryer Inspection
• First Stage of Uprate 115% OLTP Maximum
• Planned Refuel Outage/inspection "'8 months after uprate 16

- Enteng.

.VY Plant-Specific Load Definition [afternoon]

• Presentation of methods and results
• Acoustic circuit analysis
• CFD (methods)
• Strain gauge measurements

    . VY plant-specific dryer load definition 17

-- Enteity _ VY - Acoustic Loads Analysis

Purpose:

determine acoustic load contribution

    . Analytical model using measured plant data
    . Analysis has been independently reviewed 18

A-Etergy VY - Acoustic Loads Analysis (cont.) Plant-specific data collection

• VY pressure data taken at:
• MSL venturis (one on each steamline)

        . Vessel instrument reference legs (2)

• Main steam header (one on each steamline) 19

I%--EnterW N .: vy - Acoustic Loads Analysis (cont.) -U Data collection points High Speed Pressure Sensors ' (10)

- Etergy VY - Acoustic Loads Analysis (cont.) Plant-specific data collection (cant.)

     . VY strain gauge data taken at:
        . MSL, vertical run close to RPV (one on each steamline)

• Repeatability confirmed 21

U 0 0 0 0) ri-n, avo°, 0) I r-- I CJ - ) D n (D mf ' Q oDLD IV FI _.m n _c1* 0 Q~ U) o *0 I_. DN) ENOOI 0x C) H (D00 0 mJ NJ CD 0.

                       %0)   C)          U) rl~

U) 0 0r)m (D sN l 0

                             =3 f'

NJ 0 %t.. 0) Qn Ln NJu e 01N

Entergy -u vy - Acoustic Load Definition

    - Acoustic circuit model:

• VY dryer dimensions
• VY main steam system dimensions 23

IEn tegy ill-WY- Acoustic Load Definition (cont.) I , , C

• Acoustic circuit model doman (Figure - Part 1)

N11AS>//' °70 Piping geometry used in the acoustic circuit analysis. SG = strain gage; RV = relief valve; SV = safety valve; pipe with no designation = pipe stub blanked off.

                               \                  ~225° N11B 2880        2520 MSLC D = 18"\                                                     VI L = 34.76'                      I             I   I-    - - - -

SG L = 16.82' 13.01'] 4.50' 10.46'1 L = 21.34'1 SV RV RCIC C MSL D D = 18" VI L = 34.76' I6.02' T

                               'M SG             L = 19.92'                   I5.83'       L =30.31' RV        SV                          DSV24

=--EnterV VY - Acoustic Load Definition (cont)

. Acoustic circuit model domain (Figure - Part 2): vI D = 18 L = 34.76' N11A      ,

25

• -~-Entergy vy - Acoustic Load D nition (cont.)

Acoustic circuit dryer baffle nodal diagram 26

-tEntergy vy - Acoustic Load Definition (cont.)

    . Acoustic circuit model domain details:

N R a/2,- a4 bla-I *- i '4 I

                                       -  b -,

14 a_,

                                                     -I -

b2-,

                                                            - I r   V2p +

a1)2 0, l

                                 -X1                                      i
            *E-I- -Iy                  INC AX             c     .4-     e      l   9 I_-               k                                      I p1
        '.                                      Steam-Water Interface A_-                                     , Fl   t 27

do%- -Enteigy 7---."-.14. ff-L 11 - .. " vy- Acoustic Load Definition (cont.)

• Main Steam Instrument Line Data - Uncorrected:

Uncorrected MS Venturi 30 20 10 nL 0

                                    -10
                                    -20
                                    -30 0   2   4   6     8      10 12 14 16 Time (sec) l Prelminary Information          1                                    28

AsK At=

  -Entergy VY -     Acoustic Load Definition        (cont.)

m Main Steam Instrument Line Data Correction: 29 I Preliminary Information I

i- ~Ente-rg

-    w vy - Acoustic Load Definition                                                      (cont.)

m Main Steam Instrument Line Data (corrected): Vermont Yankee MSL B: 100% Power 6 4 CO! 2 15~ 0 jL C. C Cn Cn a) -2 il lrll!

           ;54
                   -4
                   -6

i. . . .. .

0 2 4 6 8 10 12 14 16 I Time (see)

                 .                                                                                   30 I Preliminary Information     I

        -- d Etergy

.. ,., VY- Acoustic Load Definition (cont.)

IL X Main Steam P-rms Venturi (corrected) CLTP 100% Venturi MS "B" 0.12 - 0.10 - us 0.08 0. n 0.06-E

d. 0.04 -

0.02 0.00 - 0 50 100 150 200 250 300 Frequency (hz) 31 I Preliminary Information I

E)7 tegy , .7 r- _

                      'If -

Acoustic Load nition (cont.) _,- -- -I -. Nodes evaluated to determine maximum vertical plate pressure r

dab A,,-- Enterg VY - Acoustic Load Definition (cont.) CLTP 100% Maximum Vertical Plate Pressure 0.07-0.06 - 0.05 -

a. 0.04 -

0 E 0.03-CL 0.02 - 0.01 - 0.00 - It. huh: 0 50 100 150 200 250 300 Frequency (hz) l Preliminary Information 1 33

gm

          -Entergy 1   - Ur vy - Acoustic Load Definition                            (cont.)

Pressure distribution across dryer vertical plates 0 .7I i I I I I I I i I I I I 0.6 0.5 en "a 0.4 V: 0.3 0.2 0.1 0 0 20 40 60 80 100 120 Closest to Node Number Closest to MSL inlet MSL inlet 34 I Preliminary Information I

Methodology to Determine Unsteady Pressure Loading on Components in Reactor Steam Domes Prepared by:

-I dontiinuum Dynamics, Inc.

Ewing, New Jersey Prepared for: Entersly Nuclear Northeast ermont Yankee Vernon, VT 35

Flow Induced Vibration in BWR Plants ES .~' . .- General Observations El: 36

Flow Induced Vibration in BWR Plants -' General Observations [[: 37

          --             Flow Induced Vibration Issues

. r . 1, I

                    .,Scaling and Physical Considerations r:S ,.I-
                    . t:

[[ 38

Flow Induced Vibration Issues

_>.

.Scaling and Physical Considerations mi F....

[[. 39

Vorticity Induced Unsteadiness El 1... 40

Figure 2l1 Oscillation in a

- ! l:stagnant branch line rowlv.-  , dO ....

Le . 41

Figure 3.2 Conceptualization .- '77-.

   -    U of source regions 42

.I.-Junctionsinthe Steam Line rt : 43

Loads Transfer Methodology in BWR Plants - Motivation and Approach Overview

                              . .. ,2 EL 44

Loads Transfer Methodology in BWR Plants - Motivation and Approach Overview

                ,. ..                   II 45

Loads Transfer Methodology in BWR Plants r- - .W'.0 ""IL Motivation and Approach Overview It 46

Component Models (continued) I , .. .. IX Figure 4.2

    *t ....
            ...IT 47

I.,

  ...d.. Main Steam Lines II[[

48

Steam Dome/Main Steam Line

  ......-rE
 -_                                  Junction Aer                      ....................................

49

. Branch Line Junction ... el., 50

7 IL-on ro Valves L v ..... 51

 ,       Model Assembly

_- I. 52

-. Model Assembly (continued) el:..... 53

Model Assembly (continued) I II ... [[ 54

I'a I' '.TE and fb for EPU Load

 -::[

Example Information 55

'.'-1-k A L I and Id forEPU Load El: Example Information 56

rl'a and 'rlb for EPU Load -- PSD .. El: 22 IExample Information 1 57

A Comparison of the data on Figure 6.4 with - 17 predictions tabulated below e El: I Example Information l 58

   .- Figure 6.4 EPU pressure time history and a

PSD derived from strain gage data r1-"

    .IT l Example Information l 59

Figure 6.6 EPU strain gage pressure and PSD predictions with the current ".7 7 1-! methodology, for an acoustic speed of

         -S
            -rr 11 ft/sec.

EL IT

]

Example Information 1 60

Figure 6.5 EPU strain gage pressure and PSD predictions with the current methodology, for I - _an acoustic speed of[[ ]]ft/sec. Fir

   . E....
                                                       ]]

Example Information 61

VY Dryer Node Diagram El2 2, 3 Pressure data locations Pressure data locations 132 2 Figure -A.1 Top and side view schematic of pressure node locations on the steam dryer. 62

r. Pressure Time History Dryer Face I Preliminary Information I 63

-- Peak Load Sensitivity 0 .0 0.0005

                    -0.001 0   20 40      60     80 100 120 Node Number l Preliminary Information     l                              64

- -7 .W Nodal Predictions

                               ,1 .;

T T TTArZ llrTl

                        -4

_ p, 2 _-........ 100% Power I......................... 2 d . -- 95% Power W., 1.5 90% Power .-

                                                                     ,  - -        80% Power                                       .

C~ 0 ... . . .. . . . . .. . . ........... .. . . . . . 1 Xv 0.5 DI--- ---------------- .... .. . -- --- --------- 0 0 20 40 60 80 100 I 20 Node Number 0.6 0.5 _ 00%

                                                                                         ,            Power ..............                         .........

iU95%

                        $:12                                .               - -                    Power.
                                              .......... I.....                 ...                Power                     .90%I ,............

0 0.4 s-I Pow er .'80%

                                                                                                                                               .   ............ 7 0.3          _ ........................           ........................................

0 C,) 5-4 0.2 .. . _ 0.1

                                                                .........                                   .............                         -'''''''''lf

0 0 20 40 60 80 100 120 Node Number 65 I Preliminary Information I

  '771 Max Pressure vs Power 2.2                                      . . .. ..                      .     .

II

                                                                                                            .      .           . l I

r--4 0 ct 0 r-4 2 I I 0 0

            ;--4

• r--

CD V) 1.8 -0 - - - - - - L - - - - - - 4 Al 1.6 ~L V) 1.4 . .L, .

                                    -- - -- -  - - -  -  -  -  -   - L.

I, I, II I 1.2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - II I I I I 1 . . . . 5 6 7 8 Feed Flow] 66 I Preliminary Information I

Load Exceedance Node 98 160~I II CPz Od1 0 0 80-- - - a s 10

                      -2             -1                           0             1        2
                      - Pre r        -r mo                                                           6 I Pre ssure (pzs id) lPreliminary Information      16

 . -7 t
         .... Time to Exceed                                       -                Node 98 109 0                                                                             -. 9-                        -1i                    Z 0         107                     -       ,                    .                      .        -                                          .

105 0 , .- 0 -, 1 IO _ I / _ I I I I 1000 0 -- - - - - - - -S 10 0.1 I cI 0.5 1 1.5 2 2.5 3 3.5 Peak Pressure (psid) 68 I Preliminary Information I

 -~~En tegy

- a vy - Acoustic Load Analysis (cont.) mAcoustic analysis conclusion:

• VY main'steam system has acoustic sources
• Correlation between analytical expectations for physical plant and measured results
• Measured results do not show high amplitude fluctuating pressure loads at CLTP m Acoustic analysis results application:
• Analysis results used to create VY plant-specific load definition 69

i-Entergy

-               Dryer Structural Analysis GE application of VY load definition to response spectrum (same as analysis of record)

GE application of RS to finite element analysis (ANSYS) (same as analysis of record) GE structural analysis calculates component stresses (same as analysis of record) 70

--=Ent~egy I

I. i. nf m o VY - Response - Spectrum 7 IPreliminary Information l 71

Dryer Structural Analysis (cont.) l Preliminary Information I 72

a=--Enteqsgy , . .E . _VY - Vortex Shedding Evaluation

   -         p

Purpose:

Evaluate vortex shedding

                 . Fluent - Analytical computational fluid dynamics (CFD) model 73

Unsteady Reynolds Averaged Navier Stokes -9 (URANS) Simulation Convnaht 2004 Fluent Inc. All richts reserved. 74

   -Entezgg a-%.-

-;I

   --rLarge Eddy Simulation (LES)   Copyright 2004 Fluent Inc. All rights reserved 75

- Entergy

-    VY - Vortex Shedding Analysis (cont.)

• CFD model development
• CFD solutions
• Unsteady Reynolds Average Navier Stokes (URANS)
• Large Eddy Simulation (LES) 76

Enterjy VY - Vortex Shedding Analysis (cont.)

  . CFD model development:

• Methodology - Fluent
• Boundaries, geometry & mesh

        . URANS domain: RPV Dome, RPV annular region, Dryer internals and Skirt
        . LES: limited domain

• URANS unsteady solution provides LES boundary conditions
• LES solution capable of modeling local vortices at cover plate 77

a=.- Entergy vy - CFD Model Wnt Inc_ '- 1 Copyright 2004 Fluent Inc. All rights reserved. S S S

• S

                       *S'U.*S SO' I S S      S  :ea.:e
                                                                                               . 95'
                                                                                                         .1 78

a--- Entergy

.I
   .~!

VY - CFD Model (cont.) Copyright 2004 Fluent Inc. All rights reserved. 79

Entergy URANS Evaluation Copyright 2004 Fluent Inc. All rights reserved.

• URANS evaluation performed to establish:
• Basic understanding of flow field
• Characterizing turbulence field for estimating LES model cell size
• Define inlet boundary conditions for LES model 80

-Entergy URANS Evaluation (cont.) Copyright 2004 Fluent Inc. AM rghts reserved. URANS model

• 875K cells, hybrid mesh
• Incompressible, isothermal, unsteady 81

A.- -Entecrgy -'I

   . U    7 LES Evaluation            Copyright 2004 Fluent Inc. All rights reserved.
       - I lc~ymlk~ I                                                           * . I,'7m
                                                                                   . . *. *.; -.           II 82

0-ax-,Wnergy LES Evaluation (cont.) Copyright 2004 Fluent Inc. All rights reserved.

• Boundary conditions same as RANS model, when applicable.
• 2 Million mesh mTime invariant profile of u, v, w, k, e from RANS solution imposed at velocity inlet 83

e-Entergy VY Vortex Shedding Evaluation (cont.) CFD evaluation status:

      - Vortex shedding is contributor to dryer loads at low frequencies

• Contribution is visible in plant data

      . Conclusion will be validated 84

VY- Load Definition . VY dryer 120% EPU load definition:

• MS acoustic loads at 120% EPU power conditions
• GE applied MS velocity scaling (RAI EMEB-B-8 response) to EPU condition 85

E A_ WVY FIV Comparison

  . VY FIV measurements comparisons:

• Benchmarking VY measured data against other plants MSL piping measured vibration comparisons 86

A-En tergy

1. VY FIV Comparison (cont.)

      . Strain gauge measurements:

VY vs. QC2 100% OLTP strain gauge measurements

• Similar noise floor " 0.014pe

             *QC has significant strain peaks at 137 Hz and 160 Hz that are not present at VY 87

Entergy

        . . ....                                                                    VY FIV Com parison                                                                                                                                         (cont.)

VY vs. QC2 100% OLTP Strain Measurements Sampb Rate, spae 1024 Spectral Plt Date: 11-Aug-2004 Sampie Rate, ss - 1024 Spectral Plot Date: 03-Apr.2004 TirmeDuration. sec 120 VY - 100% PF. Drywell StralnlPress. Ch 33 Cornposite, perms = 0.4356 Time Durafion, see 167 Quad Clfles-Z 41212004. 800MWe. Ch 34 Comnpcsite, prrr = 0.80839 n r, Ai iNdch Fifter On I ~~ I~ At Ndch Fiftr O f 0.35 0.07 W! _" 4 -____a_"--_* - <- - -

                                                                                                                                                    ----           I--J______-____                                 _______---4-r----l-0.06

• VY naximbum 0.3

                                                                                                                                                ----    I - - - - 4 _ _ _

I I I I I _____l I I 1 I I I I I I I I _ I________l I _ _ _I--I---- F --- 1 0.25 I I I I I I I I I I I I I I 0.05 --- r----I-----r-- - l-- ----- r---- I I I I I I I I I I I II E0 I I I I I I I

                                                                                                                                     . 0.2              I               I            I              I          I             I             I e                  I               I            I              I          I             I             I
                          -- - -    - --    --     - - - - - - -    -- - - - - - - -   - - - - - - - --[ - - - - - - - ]-

0* 0.04 - - - - - - - - - - - - - - 0 0.15 I- - - - - - - - L - - - - I

                                                                                                                                                    ---- ti--                       maim---I-------                       I.-I----                          --

I I1 t I' § I , I ,I I .I  ; 0.02 _ I_ I I 0.1 I I ' I 0.01 0.05 50 -. 10 0 150 2C0 250 300 0 20 40 60 80 100 120 140 150 180 200 0 Frequency. It Frequency. ; Vermont Yankee .Quad Cities Unit 2 88 I Preliminary Information I

mm--wEn tergy l VY FIV Comparison (cont.) VY vs. QC2 100% OLTP Strain Measurements 0-50 Hz VY. 100%. 20040709085303, Strain. Ch 33 OC2 800 MWE. 0402022416.DTA. Strain Ch 34 0.1 I I I I I I I I I 0.09 0.08 __ _ _ _ _ _ _ _ _ _ I I I I _ _ _I _ _ _ I__ 0 0.07 I I I I I E 0.06 a . .d

              --     I-r----4-----4                              --  5-4------l---~~~-.--

e 0.05

    .9 Ea C0 Af 0.04                                                                                                                (A I                      '              II            I         M I            I      I        I

• I I I~ I I 0.03

              --    r--r--                 4r----r----

0.02 . . . . 0.01 5 10 15 20 25 30 35 40 45 50 Frequency. Hz Frequency, Hz Vermont Yankee Quad Cities Unit 2 89 I Preliminary Information I

Entergy I%- VY FIV Comparison (cont.) -. -a

• MS Piping Vibration Measurements
• Indicator of acoustic load frequency and amplitude
• Plant EPU vibration comparisons
• Measurements performed 3 times 90

-aEtergy VY FIV Comparison (cont.) MS piping vibration plant data

• Indicator of acoustic load frequency and amplitude
• Plant EPU vibration comparisons (see chart):

        . VY CLTP data extrapolated to EPU

• Piping vibration similar to Brunswick

        . Piping vibration < Quad Cities 91

if%-EntcygT I-,-- m-%-O-w P T- -?"L VY FIV Comparison (cont.)

     -4 rL                                 EPU Maximum Measured Acceleration 1.400 1.200 1.000 0     0.800 C
    .0 ca)

U O 0.600 0.400 0.200

                                                               . 4-                                     projected 0.000 Dresden Unit 3     Quad Cities Unit 1           Quad Cites Unit 2 Brunswick Unit I Vermont Yankee I                               Plant                                           92 I Preliminary Information         I

-Entergy Power Ascension Dryer Monitoring

Purpose:

ensure dryer integrity during gradual power increase Pro-actively identify significant increases in MS and dryer FIV

• Approach

  . Acceptance criteria

• 115% step 1, outage/inspection in 8 months 93

Entergy -_Power Ascension Dryer Monitoring (cont.)

   . Approach

• Ta kE pr~ssurE, strain gaugE and accElEromEtEr data at approximatEly 2.5% powEr tEst incrEmFnts, EvaluatE LEVEl 1 accEptancE
• Hold at 5% incrEmEntal powEr lEvEls for 7 days minimum
• ComparE data to accEptancE critsria
• VY EPU rEsponsE spEctrum

         . Structural analysis ASME fatiguE limit

• Moisturs carryovsr monitoring (daily)
• REpEat monitoring for Stsp 2: 115-120%

94

  -- Ente y
         -Power Ascension Dryer Monitoring                                                                 (cont.)

I - 120% CLTP 115% Step 1 Power Ascension Target: 115% CLTP 1?. -_1;47-_M 3 CLTP I 110% I- -V - CLTP 105% A Collect Monitoring Data CLTP Evaluate Monitoring Data 100% CLTP Day 7 DayO Day 14 Day 21 95 I Preliminary Information I

7F ;Enteigy Power Ascension Dryer Monitoring (cont.)

     . Acceptance criteria

• VY EPU response spectrum
• ASME fatigue limit 96

I%--En&Tg !. .- 4 1W

          .. W JPower Ascension Dryer Monitoring (cont.)
       -S

• Dryer monitoring acceptance process LEvEl 1: comparE collEctEd strain gaugE FouriEr spEctra to EPU load dEfinition accEptancs critsria
• If lEss than critEria, dryEr structural intEgrity is confirmEd at that power lEvEl
• OthErwisE, back down rEactor power to an accEptablE lEvEl and pErform StEp 2 97

a=-Entegy Power Ascension Dryer Monitoring (cont.) U Dryer monitoring acceptance process (cont.) Level 2: compare acoustic analysis response spectrum to EPU load definition acceptance criteria

• If lEss than critEria, dryEr structural intEgrity is confirmEd at that power lEvEl
• OthErwisE, pErform StEp 3 98

@^

   -auPEntergy Power Ascension Dryer Monitoring                      (cont.)

-. JSflfla Et ., N Dryer monitoring acceptance process (cont.) Level 3: run GE structural analysis and compare to stress limit

               + If accEptablE, dryEr structural intEgrity is confirmEd at that power lEvEl 99}}