ML042510395

From kanterella
Jump to navigation Jump to search

Attachments 1 Through 4 of 07/21/2004 & 07/22/2004 Summary of Meeting with Entergy Nuclear Operations, Inc., on Steam Dryer Analysis
ML042510395
Person / Time
Site: Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date: 09/02/2004
From: Richard Ennis
NRC/NRR/DLPM/LPD1
To:
References
TAC MC0761
Download: ML042510395 (39)
v • d • e


Text

MEETING ATTENDANCE LIST Licensee:

Enterov Plant:

Subject:

Vermont Yankee Nuclear Power Station General Electric Steam Dryer Analysis Methodology Date: July 21, 2004 Time: 8:00 a.m.

Location: NRC Headquarters, TWFN Room 8A1 Name Title Organization 15"O Ais Mf IC I nq4UVL 0 P"C~

~1 PJr'-Io De-.l 4zg ~n-k c-F4~t~A L~S'e~cE?

GAPL ew~i

/41 ~c Fh ske-e

&V,0104~A-s

!I 5r-r -r'tee AtLC, I/4L4 XMEg-SC-HjAe6-i'f1PA6E12-~

44

-Q CAfm Cty-7~ 5-1M_

__A W_

-7 t

i csht~

67 1,

64~r/

/97/6d*

A l 2.

-7 k

ATTI!C~4mtxr t

2 Name Title Organization reI{A C. L4qr tqozr ^A1v 46/tR/g UL e q2 R

lzo0 vc ecy Aw 6gqec lq ftJo/IAPR D

ARLI&6 twaOwM rDE sf~ A2 E_____

e j

2t-f.

/

-3ecj C /?4-A C7AJE 7%Dz4 CccLo4 1rtt

'1l 6e-ThŽ C4T42 AiR-iR c-iIE

^ EB bi IA -L70tJ Scc~

S7h5

<E,%

gSfNs/S,7$ B cb 5 g c

__36S

___________________,U DJ r$D IE/'

E

.4

/e4@ / 40G G

2),. -c<

'sHO'I AzA7;5w Lo '4 5 4$)u ;71-k~lc(.

t*-

6 'I E ee,6,)

Si^ FoSR( e91e.

6-kI4SC MA-r--S 60j (79-z&

/izri D

C f

4, e /t VY kfi zx a A sor v t r/8ze/ c /aad g"it cr /A<

F

a.

t lSG Do^

_ _co_

_L__t

_ _ls

3 Name Title Organization

~~C, A,

N\\l C tA EAT.

)-

B ~

xc4 Soel24lo C4SC~C

~/e z/t PA4 S/)G l /

A- /CT F_ a__

Ceci w VA>

e&N,.

+

4

+

4.

t 1-

4.
4.

4.

4-4-

I 4

4 4

4 1

4 4

I 4

MEETING ATTENDANCE LIST Licensee:

Entera Plant:

Vermo

Subject:

Steam Date: July 22, 2004 nt Yankee Nuclear Power Station Dryer Analysis Associated with Extended Power Uprate Request Time: 8:00 a.m.

Location:

NIR (

HPWnnlr inrforc rlA;FK Rnnm I ('I C I

  • -ttJ1t 1tS

.' V V *

  • I *
  • tfl*,

.4 S I Name Title Organization R_______

F SZIs, P Ar M I&.-/CalL/eLr' Leslie wd(erpe~

tkex eS

,allu vzi,-r 6*r-va wuc ty RiA 4-MA01-1EA

&gE-A VXIAnpl 46 ZZX Mu -ee 6rH-xJ06xs~

GOhl0Ae emkccfi-Peo,)c-cl O4fE 6q-Frs I~ ht

/w>e t~e

___________________G RA:

S A'NANTRXJ

.\\V\\

xr F/,1 C&

/7 2

&/ci-OSL7C(/C P,%QS'ecI6 /k41 L9Eir

/YY~ec6 t nz'Rs 6c/)

Es k1L' 2c

/Cs-r JU C____

_R__________

G*NuS

~

c. S l

Ce.s C/t JgP° Dv1 Aj 7t1n

-I s

I

'7 ArTP#^CAW

D

2 Name Title Organization S

2

__eC_

A vftt4 VIt~

Ieer~~

qbl9Z

-M APLK

._v-tlv-r4pqk)

VT fo-AvU.c..r i Sv Alt a4e~nyi W-t'l fikants,QhZv3le,

[bJ N ri-g//

36 Thu s

Ii z

/A ieC /

T, 4mvd1

/4<J

~ Se-e~

c A/L2C AJ~c/*&-

N 64z¢ /tX2>A45 s

y

'z'&

6X/ e{~

Q&&fa4 AeI

.IR t Ci&

,LA,A14L

/-JQ -

ct L

X Al rcA.S V.c.

V;V- (hC4A-\\. '

MecAE. EV~

AW

. i A

~ t

3 Name Title Organization

'V7.~ (11cAZinhA

-L uAS~

p 1

JIeLv I~

cEda 4

n

.4 0!4. 6Ž-J1Z-eeif5))i 6~F-ME

~JeFF~e~,IA tso1 I&

,Q /u/o TL, SA.>

4 4

4 4-4-

4-

+

4-I

~--

U BWR Steam Dryer Structural Analysis Methodology July 21, 2004 "IDye trctra Mars etiodl ogAebg121¶O 42J Agenda

  • Meeting Goals
  • Meeting Structure
  • EPU Operating Experience
  • Fluctuating Load Definition
  • Structural Analysis Techniques
  • Finite Element Model
  • Fatigue Structural Analysis
  • Load Combinations
  • Primary Stress Structural Analysis DyrStrit W-AagW4ehaooY~ee~~72

~

rd

~~

A

-Ar"to.Et 4 3

Imagination at work 1

Meeting Goals

  • Update NRC technical staff on BWR steam dryer structural analysis methodology

- Load definition

- Structural analysis

  • Provide generic basis and background information supporting EPU dryer analyses
  • Provide information supporting VY dryer analysis review Significant improvements in methodology have been made over the last year

~f~DyerStruturl Aalyss Mll dI~i~e~6'7I~i2O4 Meeting Structure

  • Informal question/answer format

- Similar to technical audit

- Not a structured presentation

  • Review

- Detailed analysis results

- Design record files

- Spreadsheets, etc

  • Review of generic methodology

- Vermont Yankee EPU analysis used as example

  • Copies of materials requested by the staff will be formally provided after the review 5

-ID Imagination at work 2

GENE Technical Discussion Leaders

  • Fluctuating Load Definition
  • Structural Analysis Techniques
  • Finite Element Model
  • Fatigue Structural Analysis
  • Load Combinations
  • Primary Stress Structural Analysts Dan Pappone Richard Wu Alex Pinsker Henry Hwang Henry Hwang Dan Pappone Henry Hwang FDTY

~w ta ioDz2*4ye,8

,M66finjj7

°-121/2greeu 4211 Xfp Steam Dryer Design Basis

  • Original Design Requirements

- Not ASME-coded component

- Fatigue from flow-induced vibration not explicitly considered

- Maintain structural integrity for outside steamline break accident

  • No loose parts
  • Deformation acceptable
  • Current Dryer Analyses

- Finite Element Model of dryer

- Fluctuating pressure loads defined

- Fatigue from flow-induced vibration analyzed

- Normal, upset, faulted conditions analyzed

- ASME code criteria used as guidance for modifications

isvodgMtn 7

Imagination at work 3

3

EPU Operating Experience

.el i i I

/

N

/

N 4,

ft/

/

/

I Nearly 50 Reactor Operating Years of EPU Experience l

11 St

-d r?,nal1-I Methodology-I'l Imagination at work(

4

Relative Hood Stresses o14160 psi zvv366 psi Flat Hood With Strut, Sianted Hood With Plates 2294 psi vYNS Modified e650 psi Dryer FHlt Hood Without Struts Carved Hood With flates

)20ri4-S

  • r Overall Dryer Screening 120 100 t20 m~~m5

..~.ie' etc is --

fi imagination at work e

5

BWR/3 Dryer Failure History (QC2) lower cover plate at QC2 High cycde fatigue due to high frequency fluctuating pressure (120-230 Hz) thin cover plate, small welds, potential resonance Replaced coverplate with W plate Developed dryer cornponenl structural analysis Used more robust attachment welds.

May 2003 Cracks In outer High cycle fatigue Removed diagonal braces Modifed dryer structural hood, broken due to low frequency from outer hoods analysis to account for braces and struts In tluctuating pressure Replaced outer hood pltes fluctuating pressure lead the outer hood loading Hz)

Rethac-dpcuter ooda definition over fuit frequency teotrho opeationg wi Hz with 11 plate range. for aSl dryer types damaged ovwer plate Added external gussets contributing factor March Cracks In plate at Local stress Fult height 1 vertical hood Solid submodelsforNigh 2004 gusset lps, broken concentrations not plate stress locations used to tie bar welds modeled In sufficient Futt height external gussets supplement 3D shell Finite detaEliln model Full penetration shop welds on Analysis Incldes gusset Usp external gussets design and weld design 11-90 I

-e-

,

iW f

-,T..- i-

'il 0 x" 54Si a,

-r !IRA t

7ft t"'

.1, Hood Failure Locations

_I Top of Outer Hood Location)

Plat ah 'r g,,_,r:fi$*trsfi42;j~t.Ol~sxQQj~zotlw~shiSb&

¢u;>,4i>,4,~,s(,WKton)8ss=

Imagination at work 6

Review Topics

  • Load Definition
  • Structural Analysis
  • Plant Application Conclusions
  • Significant progress in structural analysis methodology
  • Overall methodology is conservative
  • Dryer modifications assure structural integrity at EPU conditions

- Increased design margin at critical locations

'H,.a+S.et;s~~l.;;~,}

4;.b

t
f

,t-.t-tt-.

i<ntZ..r-y1>t 4-A..,;~

,i, Imagination at work 7

Closed Session Iogy.';ee]ng7/

fi.Dye SiutIa A,~yi M

e U

6 Fluctuating Load Definition

  • Generic load definition Assumptions In-plant test data Scale model test data Reference load definition
  • Plant-specific application Load scaling
  • Load definition confirmation Imagination at work t

8

Structural Analysis Techniques

  • Equivalent static method

- Frequency analysis using reference load

- Load scaling

- Dynamic amplification, stress concentration factors

  • Response spectrum method

- Pressure load to response spectrum transform

  • Acceptance Criteria a

Finite Element Model

  • Model Assumptions
  • Dryer components modeled
  • Shell model
  • Solid submodels 0~

I YD rtrcua nlssIehdlyMetn '2jO

44Sdi8 Imagination at work m

9

Fatigue Structural Analysis

  • Analyze current power, EPU power conditions
  • Benchmark current power results against acceptance criteria
  • Evaluate EPU results against acceptance

.i er c'

Sndua rIiIthi Meng 220 ifflder Load Combinations

  • Operating conditions

- Normal

- Upset

- Faulted

  • Loads considered

- Deadweight

- Static differential pressure

- Seismic

~-Dryer Structural An 17 imagination at work 10

Transient and Accident Load Definitions

  • Differential pressure loads

- Forward flow transients (e.g., SORV)

- Reverse flow transients (e.g., TSV)

- Steamline break accident

  • Seismic loads

-OBE

- SSE Ka*

Primary Stress Structural Analysis

  • Analyze individual load components for each operating condition
  • Combine stress results for individual components
  • Assess overall stress results against acceptance criteria g~~e-;-t.^,~z~.z vf';Al-.s4-2t.

,.ue...~-

ryXi s.>,,9;e99.2 S

o Imagination at work 11

a-%Entergy Entergy VY Power Uprate Project

,;~

'I.:

Steam Dryer RAI Revieew July 22, 2004 1

-EnStmgy Main Steam Dryer p

2

7w What we know

-I.

Significant improvement in methodology Dryer Finite Element Model adequately reflects dryer performance under defined load VY Modified Dryer relative stresses are less than other dryer types under the same load

  • Dryer Loads are adequately defined
  • VY Steam Line velocity at EPU is less than QC/Dresden original steam velocity
  • Reasonable Assurance that Dryer will perform per current design requirements at Extended Power Uprate Conditions at Vermont Yankee 3

Future Activities Obtain and evaluate VY Plant Specific data

  • Comprehensive, deliberate, well monitored power ascension 4

Quad Cities Experience Methodologies developed after QC2 failures accurately predict high stress locations Confirmed by actual high stress failure locations 5

a Etergy

.,,-r~

.n Industry Steam Dryer Experience

_i n

.aafl

.i..M Ma l Nearly 50 Reactor Operating Years of EPU Experience 120 110 0a) 0 Edg 100 a) 90 80 X 0 A?

'S.b e"

I I

',:§ 5.

b 6

tergy 77

.t

..:4~..7T-

"'I.'trt Main Steam Line Flow Velocities 220.0 200.0 Up 14) 9 180.0 04) l 160.0 0

S E

4) 140.0 120.0 100.0

~ a. ~'

.CMO0a)

C CD 8m mm m c a

E 7

!
7 Overall Dryer Screening 9

JST.i

.fra'.

U.

Et " 20 100 -

80 -

Ea 0o co

.0 (U

.i 60 -

40 -

20 -

0 -......

l OO.OO.OOO O O OO 00 O

2o 1

o 5-5

-_° -

°

°

-00000

°

° 0

° CD (Da a-a: i ii!

! a:a! a:a! a a:CD

!i~

a!

a!aD6 0

mimmmmm mmmmmmmmmm mmM mmmmmmmmmmmmmmmmmmmmmm m

c-N mm m

om (2) 0 (aa 8

-En terg VY Steam Dryer Analysis GE developed Finite Element Model of VY Dryer Loads defined based on similar plant instrumented dryer data Results: identified increased stress areas at uprate conditions Developed robust modification - industry experience incorporated Re-ran the Model incorporating the modification and validated stresses were below Code limits at uprate conditions Significantly increased structural margin 9

--En tefgy VY Steam Dryer Inspection 7.Internal

& external visual inspection of steam dryer accessible areas

  • No outer bank or lower cover plate cracking found 10

a=Enteergy VY Steam Dryer Inspection 7.Some visual indications were found: consistent with BWR industry experience

  • Two 3" cracks in dryer steam dam were repaired & strengthened

. Caused by fabrication residual stresses Several intergranular stress corrosion cracks (IGSCC) were found (dryer end bank and drain channel)

. Caused by sensitization and weld residual stresses from original welding

. Not structurally significant 11

=I e rtfgy Steam Dryer - Strengthening Design Modifications

  • Lower cover plate - Increase from 1/4" to 5/8" Upper vertical and horizontal cover plates in outer hood - Increase from 1/2" to I"
  • Remove internal diagonal shipping braces

. Eliminate stress concentrators which were the crack initiators for the Quad Cities Failures

  • Replace dryer bank tie bars and improve weld attachment
  • Add six, full-length external gussets to hood plates Full penetration versus fillet welds

. Gusset shoe provides enhanced weld strength

  • Employed low carbon stainless steel - IGSCC resistant 12

'-~ Eterg-y

..,.. Z -

MINh*II VY Dryer - Before & After Strengthening t1 s'I I

A mug Beforel After 13

A-- Eergy m AdVY Steam Dryer Strengthening - Tie Bars 14

Af-

~-,-~Entesgy V4

'7=

M.

.y hitEr Y Steam Dryer Strengthening - Hood 15

-- -Entergy VY Steam Dryer Monitoring

  • Measurements consistent with SIL 644
  • Moisture carryover levels
  • System parameters (flow and level)
  • Inspection in planned refuel outage ('8 months of <115% uprate operation) 16

W tergy

~I.-,-W VY Acoustic Circuit Model m Collect VY Main Steam Data

  • Develop Acoustic Circuit Model n Reconcile Test Results with GE Analysis 17

-Entifflgy VY Main Steam System Data Collection Measurement locations more extensive than other stations

  • Pressure data taken with high speed recorder at:
  • MSL venturis (one on each steamline)
  • Vessel instrument reference legs (2)

. Strain Gauges located on each steam line close to vessel

  • Data taken at 80%, 85%, 90%, 92%, 95%, 97% and 100% power 18

1 -En te gy I.,..-d VY Steam System Data Collection Map RPV Level Instrument Reference Leg High Speed Pressure Sensors (10)

I 19

-5.

I

.4-V e

'!L..

VY Steam Dryer Timeline Feb 2004 Mar2004

, Apr 2004

" May 2004 Jun 2004 Jul 2004

, Aug 2004 X Sep 2004 I

I I

I I

I I

I VY Review/

Oversight Tech Review RAI Set i Submittal GE Audit RAI Set 2 Submittal Design Inspection Modification

<;;.t!';;.F.Q:8&,sitActB)a.4-<

4 d1.w s,;o t

-jgfet a r771 A

F;7.,75, 77-1 A

Piping Vibs Data MS System Data Acoustic Ckt ACM Complete A

AL 20

VY Uprate Testing and

.eInspection Plan

  • Two Step Uprate
  • Gradual Power Ascension Test Plan with predefined hold points
  • Pre-uprate testing provides baseline data
  • Measurement program
  • Steam System Pressure Transmitters
  • Installed Plant Equipment Inspection in planned refuel outage (8 months of <115% uprate operation) n Detailed inspection consistent with SIL 644 21

7I.

Q&A

--r.-.

As....-

22

Retrieved from "https://kanterella.com/w/index.php?title=ML042510395&oldid=5395781"