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~
-2-5-1M_ _ _ __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 -1 -,.
+ 4
+ 4.
t 1-
4. 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 CI .- - -*-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-vawuc 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& /72
_ __ _
&/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_ _ _ _ Avftt4 VIt~ Ieer~~ qb|9Z -
-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/*&- N64z¢ /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~
cEda4n .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
~-- -
UBWR Steam DryerStructural 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* Transient and Accident Load Definitions* Primary Stress Structural Analysis
DyrStrit W- AagW4ehaooY~ee~~72 ~ rd ~~
A -Ar"to.Et 4 3Imagination at work
1
Meeting Goals
* Update NRC technical staff on BWR steam dryerstructural analysis methodology
- Load definition- Structural analysis
* Provide generic basis and background informationsupporting EPU dryer analyses
* Provide information supporting VY dryer analysisreview
Significant improvements in methodology havebeen 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 beformally 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* Transient and Accident
Load Definitions* Primary Stress Structural
Analysts
Dan PapponeRichard Wu
Alex PinskerHenry HwangHenry HwangDan Pappone
Henry Hwang
FDTY .-' ~wta 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
;isvodgMtn7
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 |
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 Modifiede650 psi Dryer
FHlt Hood Without StrutsCarved Hood With flates
)20ri4- '>." .S *r
Overall Dryer Screening120
100
t20
m~~m5 . .~ .ie' ., . . .
etc
is --fi
imagination at work e
5
BWR/3 Dryer Failure History (QC2)
lower cover plate atQC2
High cycde fatiguedue to highfrequency fluctuatingpressure (120-230Hz) thin cover plate,small welds, potentialresonance
Replaced coverplate with Wplate
Developed dryer cornponenlstructural analysis
Used more robust attachmentwelds.
May 2003 Cracks In outer High cycle fatigue Removed diagonal braces Modifed dryer structuralhood, broken due to low frequency from outer hoods analysis to account forbraces and struts In tluctuating pressure Replaced outer hood pltes fluctuating pressure leadthe outer hood loading Hz) Rethac-dpcuter ooda definition over fuit frequency
teotrho opeationg wi Hz with 11 plate range. for aSl dryer typesdamaged ovwer plate Added external gussetscontributing factor
March Cracks In plate at Local stress Fult height 1 vertical hood Solid submodelsforNigh2004 gusset lps, broken concentrations not plate stress locations used to
tie bar welds modeled In sufficient Futt height external gussets supplement 3D shell FinitedetaEliln model
Full penetration shop welds on Analysis Incldes gusset Uspexternal 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 analysismethodology
* Overall methodology is conservative
* Dryer modifications assure structural integrity atEPU 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 t8
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 againstacceptance 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 eachoperating condition
* Combine stress results for individualcomponents
* Assess overall stress results againstacceptance 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 VYPower 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 loadVY Modified Dryer relative stresses are less thanother 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 PowerUprate 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 failuresaccurately predict high stress locationsConfirmed by actual high stress failurelocations
5
a Etergy..- -. .,,-r~
,; . .,
.n Industry Steam Dryer Experience_i n _ .aafl .i..M . .-
Ma | Nearly 50 Reactor Operating Years of EPU Experience
120
110
0a)
0
Edg 100a)
90
80
X 0A?
'S.b
e" I I
',:§ 5.
&, b
6
- tergy
.77 . . t, . .:4~. .7T-
"'I.'trt Main Steam Line Flow Velocities220.0
200.0
Up14)
9 180.0
04)
l 160.00
S
E4) 140.0
120.0
100.0
~ a. ~' ….CMO0a)
C CD
8m mm m ca E 7
;!:7 Overall Dryer Screening9 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!aD60 mimmmmm mmmmmmmmmm mmM mmmmmmmmmmmmmmmmmmmmmmm 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 dataResults: identified increased stress areas at uprateconditionsDeveloped robust modification - industry experienceincorporatedRe-ran the Model incorporating the modification andvalidated stresses were below Code limits at uprateconditionsSignificantly increased structural margin
9
--En tefgy
VY Steam Dryer Inspection
7 .Internal & external visual inspection of steam dryeraccessible areas
* No outer bank or lower cover plate cracking found
10
a=Enteergy
VY Steam Dryer Inspection7 .Some visual indications were found: consistent with BWR industry
experience• Two 3" cracks in dryer steam dam were repaired & strengthened
. Caused by fabrication residual stressesSeveral intergranular stress corrosion cracks (IGSCC) were found(dryer end bank and drain channel)
. Caused by sensitization and weld residual stresses fromoriginal 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 theQuad 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
IA .
mug
Before| 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 ('8months 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 otherstations* Pressure data taken with high speed recorder at:
• MSL venturis (one on each steamline)
• Vessel instrument reference legs (2)
* Main steam header
. Strain Gauges located on each steam line close to vessel
* Data taken at 80%, 85%, 90%, 92%, 95%, 97% and100% power
18
1 -En te gy.. .
I. ,. .-dVY Steam System Data Collection Map
-.
RPV LevelInstrumentReference Leg
High SpeedPressureSensors -
(10)
I
19
-5 . I.4-V e '!L..
VY Steam Dryer TimelineFeb 2004 Mar2004 , Apr 2004 " May 2004 Jun 2004 Jul 2004 , Aug 2004 X Sep 2004
I I I I I I I IVY Review/
Oversight
Tech ReviewRAI Set iSubmittal
GE AuditRAI Set 2Submittal
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
APiping Vibs Data
MS System Data
Acoustic Ckt
ACM Complete
A
AL20
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• Main Steam and Feedwater FIV Accelerometers• Steam System Pressure Transmitters• Main Steam Line Strain Gauges• Installed Plant Equipment
Inspection in planned refuel outage (8 months of <115% uprateoperation)n Detailed inspection consistent with SIL 644
21
7I. Q&A--r.- . As....-
22