ML20236T010

Nonproprietary Point Beach Unit 2 Steam Generator Tube Fatigue Presentation

ML20236T010
Person / Time
Site:	Point Beach
Issue date:	11/30/1987
From:	WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
To:
Shared Package
ML19302D102	List: ML20236S986 ML20236T001 ML20236T010
References
WCAP-11672, NUDOCS 8711300232
Download: ML20236T010 (87)

Text

__

L s.

k.

.. )W ~

.\\

i !\\,

WFM100SE CIA 7S.3 3.,

....,8,#

a t

/f q

'. [ l ../-

' 14 CAP-11672 h

r

(

y i-i

s

-h 4'

f a

j) o e '

pf "4

i t;

,g I

^

4

!{

..s i

POINT PEAN IJNIT E STEAM CENERA3tR 'b',E FATIGUE

,e PRESBfD&IN.

3 j.

NOVEMBER 1987/i

)

n-oh

/

.p 4'

r

/

>4<c

t. 'g

' t.

6 g.

i f

9

./

j

+

}ll,.

p,( L >

s

/

,s '

t' s

HORK PEPfEB1D WDER SEOP CRDER MK7D-7632A

, \\ ', e

~

e t

s il P

y

• ,g WESTIN3H00SE ELL'1RIO CERPORATICH POWER SYSTOS RJSINESS IJNIT P. O.,BOVs.455 1

PITTSREN,PM15230-0355 8711000232 871124 PDR ADOCK 05000301'-

.g 9

PDR:

_ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ -_. _ _ 'j,

.T-j

~, jo p 1:'

4

A meeting was held ori 11'/4/87 between Wisconsin Electric Power Company, Westinghouse and the NRR Staff addressing the potential fbr tube fatigue

> failure'in the Point Beach Unit 2 steam generators. The following agenda

+

items were addressed during the meeting:

l 1.

Review of the North Anna' Unit 1 Fatigue Failure Mechanism and Criter1>

a i

2.

Contributors to Fluidelastic Instability l

It 3

Air Model Tests for Flow Peaking Effects 4.

Point Beach Unit 2 Tube Fatigue Evaluation A copy of the' slides presented by Westinghouse to the NRR staff is

'l

, contained herein.

I

, ' 1 t, f

46 i

t Q

I l

e i

l

s

'i POINT BEACH UNIT 2 TURE FATIGUE EVALUATION NRC MEETING, NOVEMBER 4, 1987 AGENDA INTRODUCTION / PURPOSE FRIELING 9:00 REVIEW OF FAILURE MECHANISM & CRITERIA ROUTMAN 9:15 o

PUILED TUBE EVALUATION

SUMMARY

e DEVELOPMENT OF 10% CRITERIA e

CONSERVATISM OF 10% CRITERIA CONTRIBUTIONS TO FLUIDELASTIC INSTABILITY PITTERLE 10:15, o

TUBE DAMPING e

14 CAL FI4W PEAKING e

IMPLIED STABILITY RATIOS FOR N. ANNA R9C51 AIR MODEL TESTS FOR FLOW PEAKING EFFECTS CONNORS 11:00 LUNCH POINT BEACH li, VALUATION e

CRITERIA FOR EVALUATION PITTERLE 12:30 e

EC DATA AND AVB POSITIONS l

e FI4W PEAXING FACTORS FOR POINT BEACH e

STABILITY RATIOS FOR CRITICAL ROWS HOUTMAN 1:15 e

COMPARISON OF UNSUPPORTED TUBES TO R9C51 e

CURRENT FATIGUE USAGE OF WORST TUBE e

CONCLUSIONS DISCUSSION ALL' 2:00 f

t e

b,;

y

~

n ot nesien

-W a'_

w c

C4 l

1 e'

3 i

Approstaste g'

Septen of Sognda p

of81st1ers Sevndary herringhene of Flat r Pattern aesten g

aestea s

t s

e

- pc' 27C*===

j

,a

'S 4

B3 E!

J 9*

y A

(

1 4

1A8 A-A F.T L

Cesrae Tert W e

and Stapief Beture

+,g, g snatu u s ersstas or tr.rw s.rreis an,.t.u mntas"C' Colf Leg.

of Tote RM ll. S/G e

• l i

4,l s

, 8

• 1.5/1.8. ta.

B

NOTF estar Attest l

8 * !! e ts.

'N 8....,.

9..

~

8.C

- n-V :: =

ry i

i Vl e

.n.

Intemal testtag h

Y 4'

s 2.sn.o. se.

g j

3,3 gt;r, 4,

neartisr,e,vidsed

.s.s.us.,.t..

e, Arrows !adisata ofenc. ten of Freedt hets:

a mtten Schnatic Rapessar.tatten of rutimrt Sturves Swt itR fratte raphic Darinatten of fracters Isrface of f R,9Cll,g&/6 *f.* C418 L89 7

e es e e

s.,

~

Stress Amplitude for brack initiation Is Base' don Measurements Taken from the Examination of the Pulled Tube s, c.

i I

Result:

4 KSI < GA<10KSI

=

l'

]

l 4

i i

~

$ba l

The Allemating Stress Leve1 Contributes to Evaluation of Leakage as the Crack Grows Jo&

O a

e Ah 5

e e

O 9

e e

6

~

i l

l

___-___-__________-__D

9mm 4

N Laak Rates in 0.875* Diameter x 0.050' Wall Tubing g,4 s 1

O 4

m i

3 O

e a'

'E We g

g e

e e.

e a

g s*

s

~

dT I

i O

e O

g 9

O e

L) i i

e e

I.

I i

4 e

9 b

Ye-e 9

e G

e 9

OdS *31W Nyr1 e

8 e

e y

6 e

O

+#

9 ye i

i e

S

Evaluation of Tube Rupture Mechanism KeyFractography Analysis Results

• High Cycle Fatigue Failure (*10* cycles)

From inittstion to Separation

• Cuter Surface Crack inillation at 90* to the Plane of the'U-bend and SIlghtly Above the Top of the Top

' Tube Support PInte

• Crackinitiation Stress Amplitudes in the Range of 4 to 10 KSIin the Presence of High Mean Stress

• Crack Propagation Stress Intensity Resches 60 KSI Vinch at About 90'Hs11 Crack Angle from the Infilation Siti e

e

O s

~

Evaluation of Tube Rupture Mechanism i

Steady State and CycIle Stress Evaluations 4

• Crackinitiation-Cumuistive Fatigue Usage orHigh Enough Stress Ampiltudes in the Presence of Significant Mean Stress

• Crack Propagation-Effect ofincreasing Crack Size on Tube Behavior

~

W 2

O o

l

=

4 1

1 1

j l

I Evaluation of Tube Rupture Mechanism Crackinillation Considerations Operating Conditions -

• Assessment of Axisymmetric Denting '

Flow induced Vibration Mechanisms / '""

4 e

G

. 1 1

}

Evaluation of Tube Rupture Mechanism

\\

q Operating Conditions Analysis is based on the Westinghouse Design Specification forNorth Anna Unit 1 j

The total number of normaland upset transient cycles

=

that could have been experiencedin 9 calendar years.

\\

is less than 10,000 cycles Attemsting stress levels from these transients are moderste to-10w with a calculated fatigue ussge of '

'less than 0.009 Number of cycles and fatigue usage are too low..

I 1.

Evaivation of Tube Rupture Mechanism i

i Assessment of Axisymmetric Denting

• An ineinstic' analysis of the R9C51 tube has been performed based on eddy current measumments 1.

with the axisymmetric denting component of 2.5 mits msximum isdinidispincement at the TSP c'enterline 2.

tapering to 0 mils at the top of the tube support pinte

• Axisymmetric Dentingproduces boundarycondillons whlch concentrate axist bending stressjust above the top of the tube supportpiste

• This smallamount of axisymmetric denting can

~

produce a residust mean stress equal to Ifu'habove the

~

top of the tube supportpiste.

Mean stress is significant with a smallmagnitude of denting.

e

.___.____.__._______u

Evaluation of Tube Rupture Mechanism 1

~

Turbulence Induced vibration is verylow 1,e.

Vibration frequencyis which wouldresultin y

t si.

1 In 1yearofoperation at 75%

sys!! ability.

The RMS modal vibration ampfltude for R9C51 is

. >, e.

iandis out of plane to the U bend

^

O g

)

}

1 S

1 1

Evaluation of Tube Rupture Mechanism Muld elastic Instabilities have been oliiserved

~~

l

{

1 Vibration is out-of-plane to the U bendandis at a

- s, e.

-is frequencyo(.

which wouldresultis cycles in 1 year of operation at 75% sys!! ability.

l l

The bending stress ampiltude for R9C51 for ths first mode of vibrationis{

}oh displacement i

A displacement of 100 mils results in a stress of i, s

.a Under off nominsi conditions, Ins tability is possible Number of cycles andlocation of maximum stress are l.

^

consistent with the ruptured tube and the potentialexists for.sufficientlyhigh stresses.

O e

i i

l J

1 4

.j Evaluatioh of Tube Ruptufe Mechanism l

i

.i l

q l

Potentialressons forInstabilityin R9051

}

)

{

i Reduced damping due to fixity of tube from denting at the top TSP l

i Localgeometry effect on the cross flow velocity, l

density or voldfraction l

=

e 9

i i

e e

G 8

e

Evaluation of Tube Rupture Mechanism The Probable Cause of Crackinittstforiis Lim!!ad.

Displacement Fluidelsstic Instability

• Eddy currentinspection confirms that no tube contact occurred with ad] scent tubes in the apex region 9

• Test dsts confirms that displacements for unstable tubes remain limited for a given flow rate G

8

\\

j e

e

o e

4

• srsacmam awr. truss vanses tsar enican 3

a urar

-se,e, essa so, e

.ss,

.s.

I..

s g

.E a

e a.as.

a g

[s a

I.es.

e a

e s8 8'

a4e 34e sk

.4.

ed.

onecarr, name e

l e

g e

e q

e e

O G

pg 6 O e

e 5

e

p i

~

Evaluation of Tube Rupture Mechanism

\\

Stresses Required for Consistency with Fracture i

l

)

l The crackgrowth analysis has producedan estimate'of the stresses Implied by the striation spacing Al crack initiation, a tube stress of 4 KSI to 10 KSI and the corresponding Impiled displacement are

' required At the hsIf crack sngle, G = 90*, a stress intensity AK = 50 KSidlnch and the corresp~onding displacement must be obtained o

e e

e

L 1

Evaluation of Tube Rupture Mechanism l

• Initistion Strese nndimpiledDisplsoeinent The implied nominsIinfilation dispincement ampiltude is obtained from the dynamic first mode response of the.

t, &

U bend with dented,'

conditions at the top tube l.

supportpiste

. a 6-s The unit stressis

~

c1 displacement at a

the apex i

l

. To get a nominal. stress amplitude of 7KSI, the j

necessarydisplacementis pi t

~

' DEL,=j

~

~

=

~

l i

O e

E5aluation of Tube Rupture Mechanism

~

t Effect of Cracking on Tube Response As cracking progresses around the tube circumference...

1.

the vibration amplitude of the tube w!Ilincrease, 2.

frequency of vibration will decrease, and 3.

the frequency decrease causes a drop in critica!

1 velocly.

4.

A drop in critica.1 velocityincreases tube Instab!!Ity.

9

\\

e

)

Evaluation of Tube Rupture Mechanism

}

l

~~

~

Propagation Stress andimpliedDisplacement The crack growth analysis establishes the tube bending displacement needed to get a stress intensity of 50 KSI Vinch at a crack half angle of 90*

. 4, e.

The displacement requiredIs

,st a crack half '

angle of 90*

e e

~

W l

t e

e Evaluation of Tube Ruptur.e. Mechanism Displacement vs Crack Angle ebb r i l

l

\\

\\

i a e e

e

=

4 w

9

_._..__________._.___-_~.a

-m

~,e t

e.

O 1

4 q

1 1

l

}

O g

e me e 9

99 e

L 3951433&ITT DISFSACENDft 98 8385 MIX $0052 gfhj6

?

. 1

- J f

1 q

O s

e O

e 9

e h

e O

9 e

o e

O O

I e

6 e

e l

O ge O

O e

Evaluation of Tube Rupture Mechanism

~

Conclusions Normaland Upset Conditions are not a significant factor

' Denting provides a source of significant mean stress andreduces damping during tube vibration a

Limited disp.lacement Fluidelssilo excitation provides the necessary displacement and stress smpiltude to produce rupture of the tube at R9051 O

e G

i

~

. Acceptance Criteria 1

i i

GeneralAhproach.

~

~

~

~

~

i With' limited displacement fluid elastic Instability thi probable cause, the generalapproach is to...

1. Reduce the effective velocity to below the criticalvelocity, or

2. Reduce tube displacements sufficiently so i

thatstresses become acceptable

)

s

~

e 4

5 f e. ' A N 'i^ }

,,s s

\\.

t Acceptance Criteria

/

/

Dependence of Displacement.(or Stress) on Stability Ratio T

y Testing indicates that an unstable tubecixperiences a 4

much higher order change in di facement than the a

changesn velocityorstabilityla L;,

• The log-iog slope, s, of dispiacemy,nt versus v ),y lormore.,

stabilityratio ranges from s

(

c:s ki,

M..

)

• Since stress is linearlypropodonal to l

displacement, the ratUo of the new stress &

I aftera change in stability ratio, SR, to the ld stress,%, is...

i

,, e

\\;

v

\\

)

>ll g

~

1 E

j'

, <, )

{ } ',>

e

/,

1

\\

4)

J e

f Y

f,U' Lll'.

'1 7

-i

c r

1 l

e i

l l

I

\\

l l

/

t I

r, l

i f,

{

o, J

g.

, ?.

\\lc.

.. /;

i i

~

j 0

4hb l

WISMft9M 938P WS rrentL37V 38739, heaf 9 96L 51 I

o f

/

l' I'

f

\\

.t g

t

't h

,d j

f k

I i

a o

,\\

f s

\\

\\

/

\\

(,

4

), i,.

,,f o

1 J.

Y e

I

.f#

g g

~

1 s

(

s l

i c*

i ;-

g O

j.

/

n e

E

(

/

(

s

(

8

,+

)

}_',

+

4 Acceptance Criteria Apparent Minimum Fatigue Strength of the Row 9 Column 51 Tube The rninimum. fatigue properties, stress amplitude ' '-

~ '

versus cycles to failure, for alloy 600 tubing at 600*F is...

y y

s o

k 4

1 Ii l

t a

~

e e

Aa=ma-______.__._m___. _ _ _ _ _ _ _ _ _, _ _ _ _ _ _ _ _ _, _ _ _ _ _ _ _ _ _

j l

e i

p S

O e

8 G

• ee W

goe ee comp ** MS 6

rarnaus.stanecrneases in avr unrui er seer d 4-1 e

1 l

l

~

1 l

1 l

L e

o e

e' e

e e

e e

e "O

e e

)

7 Acceptance Criterla Boundthe Problem be bounded by..ge 'ofinitiating stresi amplitud Thepossible.ran

= Thi tota'19 ears of operation, 9 years, which give)s the minimum stress amplitude, 5.6 KSI.

• The maximum initiating stress implied by the a,e fracture analysis - working backward from the l'.

mil displacement for G-90*, the minimum

,^

change in displacement is defined by the frequencyratio with n-1,

• a.

- s, s t

DEL, max "

~

o The maximum stressis I

Q~ max

• 9.5KSI

]

i I

I l

)

j Acceptance Criteria Assessment ofFuture Fatigue Usage-g

(?

j t

Minimuin stress case with a 5% reduction in stability ratio, 6g~ - 3.95KSI U

,0.0207peryear Maximum stress case with a 10% reduction in stabilityratio, G -

3.96KSI l

d~

'o.0209peryear e

g g

e 9

e l

I I

1

,f 4

g'i 4 '

e 1

e o

e

, e ', -

e 9

4 3

l' l

' ' 8-e e

e e

e

\\,,

e L-8 S

e g

resses stamerm.ases an eve esta at seer d 8,61

~

4 G

O g

e 9

a

' 9 s

A

• , e e

E s

e 9

O O

e I

g -

G e

0 y

9 e

9 e

• e Q

e 9

9 e

t S

_____7___v________

a g.

O e

j I

e n

O e

g e

a 4

• e e

4 9

8 8

e l'

e e

y e

-e NtlWS SfSDWth*S6H $N M mfd St M

$1 1 e

6 9

4 e

'e O

I M'

O O

m o

e e

e O

e I

e I

e G

e S

e 9

e 8

9 O

p

\\

4 O

y 9 e

9 4

l e

e

.. Acceptance Criteria Lookat Variations to valuate Conservatism s, u

= Maximum stress case with fatigue curve and a 10% reduction in stability ratio U = 0.005peryear s, e.-

• 9 years to failwith[

J fatigue anda 5%

reductionin stabilityratio, Tmin " 7KSI U = 0.0107peryear

• Maximum stress case with lowermean stress ae and.10% reductionin stabiliti l

ratio, Tmax *116KSiand U = 0.0142peryear 9

I 1

l l

)

1

)

l

.- c Acceptance Criteria Cumulative Fatigue Usage for Row 9 Column 51 Stress amplitude was a maximum during the most recent fuel cycle Normalized Stability Attemating

, d,c FuelCycle Ratio Stress Days Cyclesat j

~

a. 6u, Tu 1.0 1.0 170

b. 2,3,4 0.995 0.970 898 c 6,6u (95) 0.961 0.788 204 d 2(95),3(95),4(95) 0.949 0.72 8 25 1

e. 5,6(95),6u(90),7u(90) 0.937 0.678 349 Totalcycles j

A cumulative fatigue usage of 1.0 is obtained for a most recent stress empillude of 6660 ps! and the most cumuistive usage occurred during the second to the fourth fuel cycles.

Allemating FuelCycle Stress N

n/N no &

a.

6660

~

b.

6460 c

5250 d.

4850

~~

e.

4520

.j Total Usage 1.004

J s.

Acceptance Cdtena

~

1 Threshold Stress Amplitude for Continued. Crack Growth Reducing the stress amplitude to 4 KSI or less gives very low future usage peryear, but what if a small crack has been undetected and doesnt leak?

• A 125millength thru-wallcrack willnotgrow with an applied bending stress of 4 KSI.

O e

e e

9

\\

l j

1 Acceptance Criteria Conclusions 1

Tube vibration stress amplitudes can be sufficiently reduced by a 10% reduction in stability ratio l

l Future fatigue usage drops to less than 0.021 peryear j

l with bounding calculations.

I 1

A currently cracked tube with a thru-wall crack up to 125 mils long will not experience crack growth with the nominal bending stress reduced to 4 KSI.

The stress amplitude for the most recent fuel cycle at Row 9 Column 51 is calculated to be 6660 psiand the failure has been shown to have been developing over the operating period since the first fuel cycle when denting occurred.

1 i

' CONTRIBUTIONS To FIDIDEIASTIC INSTABILITY i

PRIOR NORTH ANNA EVAIDATION i

e TNO POSSIBLE PATHS LEADING TO INSTABILITY 1

e. IDN' DAMPING PATH.

TOTAL DAMPING APPROACHES IDWER BOUND MECHANICAL DAMPING VERY IDW FLUID DAMPING e

IOCAL FIDW PEAKING PATH IDCAL FIDN PEAKING AIDNE LEADS TO INSTABILITY CONCURRENT WITN NOMINAL DAMPNNG FOR CIAMPED TUBE l

t :

CURRENT ASSESSMENT i.

l e

IDCAL FIDW PEAKING FACTOP3 ESTABLISHED BY TEST e

CAUSATIVE PATN FOR INSTABILITY IDCAL FIDN PEAKING

, Ar t TUBE DAMPING FCR

1. OR DENTED TUBE WITH

- 25% UNCERTAINTY"

~

l 1'

P

. n, c.

Tube Damping for Support Conditions i

sL Tube Support Conditions Influence of Reduction In MechanicalDamping Reductionin Fluid Damping

- Elimination of Crevice Damping 1

Nomins! Damping Reduction b

si,e l

1 Measured Mechanical Osmping i

for a Row 9 U bend in Air ft 1j 0

i s

o' 1.

5 1

1 1

l t

~

'.=

1 l

r s

Damping vs Shp VoidFracdon 444e' y

Y 9

l e

e 6

e O

M a muun d

'O e

1 di

,4ce 4

f.

l i

I 1

4 i

i l

I i

e m

Figure 1 Test Equipment

e1 e

\\

.i 1

't i

m

,i

{.

1 I

l I

1 1

1 l

i f

1 1

l

~

l Fig. 6 Damping Ratio vs Tube Response 9

Row.9 l

O

-m.-________

_-.-_._____m..--.-_____-.___.--___mm.-__.___

IOCAL FIDW PEAKING CONSIDERATIONS FIDW PEAKING FROM NON-UNIFORM AVB INSERTION DEPTHS PEAKING FACTORS OBTAINED FROM AIR MODEL TESTS e PEAKING FACTOR DEFINED AS RATIO OF CRITICAL VEIDCITIES BETWEEN 2 AVB POSITIONS UNIFORM AVB INSERTION USED AS REFERENCE CRITICAL VIIDCITY APPLICATION OF AIR MODEL RESULTS TO STEAM-WATER dg lp C

~

i

-.--._-._.__-.-_--__.x__

d O4 0

e ggu O4 1

l P

y

@4 l

2 su o

@4 3

v i

e rP 0@@4 4

5 0@@4 sno I

0@@4 6

dn e

l

@@4 o

7 b

is e

iV b

@4 8

u to T

n d

@4 p

9 e

B li V

a 0

A F

@@5 e

bu 9@@5 1

T d

@@5 2

e e

t l

c b

e

@5 i

3 s

p i

s V

n i

@4 B

t 5

V o

A N

@5 5

Q@

1 0

9 8

r e

1 1

.~

n l

l ll

,S'-

'Mi g

I

\\

e 1

Ell' I

FIGURE 1 ZDCAI. TEIACITY FEAKING FACTOR IN U BEND OF 30175 ANNA 1 STEAN GENERATORK (TTFE I AND II ATS INSEETION)

}

i;

FIDN PEAKING FOR NORTH' ANNA R9C51 AVB CONFIGURATION TEST RESULT FOR R9C51 AVB CONFIGURATION 4, 6 s TEST PEAKING' FACTOR =

REIATIVE To UNIFORM Rio AVBS

- d, (,

FACTOR =

APPLIED TO STEAM FIDW WITH DAMPING EFFECT

(, G

'e TEST PEAKING FACTOR =

REIATIVE TO UNIFORM R11 AVBS

- 4, c, FACTOR =

APPLIED TO STEAM FIDW WITH DAMPING EFFECT

~

ESTIMATED STABILITY RATIO FOR NORTH ANNA R9C51 e CALCUIATED USING L

"I' 8.R. =

=> e t s

e INCORPORATING PEAKING FACTOR OF

=

., 4, s S. R. ' =

o INCORPORATING DAMPING UNCERTAINTY OF 25%

~

' de d STABILITY RATIO RANGE IMPLIED FROM TUBE FAILURE ANALYSIS s, &

e BASED ON STRESS AMPLITUDE OF IMPLIED FROM FAILURE ANALYSIS e VARIATION OF 8.R. WITH SIDPE OF AMPLITUDE VS. S.R.

-,, e

,O g

e e

q1

)

i

\\liJ

+

u, R

E B

M U

N N.

M UL.

O.

C.

~

S.

V_

2.

R.

S A

N.

N A

H T

R m

O N

~

9b na5 lll-

\\ll'L

s I

I FLUIDELASTIC INSTABILITY CONCLUSIONS 3

-9 INSTABILITY CAUSED BY

.46 1

e REDUCED TUBE DAMPING CAUSED BY DENTED, TUBE CONDITIONS e

14 CAL FI4W PEAKING DUE TO VARIABLE AVB INSERTION DEPTHS PREDICTED STABILITY RATIOS CONSISTENT WITH VALUES IMPLIED FROM FAILURE ANALYSIS

\\

E i

l i

i 1 =

1 l

a 4

ATHOS NODELING UPDATE s.

e-REVISIONS TO MODEL

~

~; e &

r

~

e M

W OATECTIVE 4: 6 buum i

4 4

l

l-

[.

'. e.

C A:e 2

- Afi l; c-Q

=

/

8 4

4 e

9 e

We 1

HpT LM S!w PLM/ Vis& or= Mspet.

wirw 2.rxnxM Nesr1 I

.___-____-__a

'. h'd 3 a,bs t l

l 1

k P.

w i

hot LEf S/JE P44) VtBV of MosEL WirH toxiox31 MESH "

(Wwra A*wA)

,Y '

__.--,..n--

h 4

h f f

1 1

6 1

1 1

I h-I Ii l 1

4 m

'-4 5

i

~

i e

hk n-x e 5*

1 X

1 1

4l l

a i

I

\\

3

\\

l l

1 l

~

E4EVATiod VIEN OF NORTH MA!A MML WM ton /x16 ffEsti u_--------

J

• ~ ~

• g

(

(,OdO O

,g Y

~

Ll

l-s),1

)

\\,

1 j

o 1

1,\\

o

/

}

7 ', l r.

i a

\\.

o.

e:<

(

i t,,

,/ l r

I y

l-

/'

a y

't L

t'

(

j

(

\\-

l a

g

\\

\\,'

' i

. $g

~

40

/

-{

g x

s

\\,.,

I'

.k

/

I

\\

\\

\\

b

,s

,' '(

o, t

s l

r

\\

((-

4 r<

.g c

c EUVApoM VIEW on AdeS ktML Wml ortIx11 MNH CNwnf AMA) 4:

k

1

u..,

m a

4 i ).

(/.

1

,.. 8.. a j

8, 3,

.y c

f h

l

H.

A

~

y.

'\\'.

t.

J 1

7 j[i.

b)

Q-o' y

';f Q'

- o t

f w.

^]

.E ir Y ['

'f g.

y','

1 ib.3

.Q- '

. l.

'f>,

b) z'

.(

K' i,

.g 7

g

-I r

O f.

l-O Z

s

,_J

('

O O

'\\

([)

s,

,.i

/s -

i t.

~',

s X,

\\

(/)

,e

<C Z

J

.i

/

011YW A.trhGY15 i

i l

i

o--

o R,

w,,.

v 1

. o, 4

\\

9'.

n j s p

- It

..)

)

',,' r.n ') \\

.,'y-aw,,c},

)

a l;j,?f l5

b '

~..f

.i;)

~,

"+-

hLOW. DISTRIBUTION COMPARISON

1. 'I' '

1

.jf

- e 4

I

,i.p y

'j)G s

, e.t c, I.\\

1

)

u

\\

i l

1 n.

j i }

,,r-i'

.'.'I, de t

I i

'. )

y

'i f

s o'

,,f i

4 c

1

- r D

0 e

'4 i

e

).

</[

(h

< l~

l

)

WIND TUNNEL TESTS ON CANTILEVER TUBE MODEL OBJECTIVE:

Investigate the effects of tube /AVB fitup on flow-4, f, g, Induced tube vibration.

1 i'

l

~

9 WW8 e

e

1 y :..

J..

+,

-)

. 't -

- I ',)

r.

- V.

.i

.y:

i g.

1 1

l i

1

. Test Stand Photo 6

o G

l'

,,.y--

a m-r, m.

i WIND TlJNNEL TESTS TO DETERMINE THE EFFECTS ON FLUIDELASTIC INSTABILITY OF COLUMNWISE

~

VARIATIONS IN AVB INSERTION DEPTHS OBJECTIVE:

Investigate the effects of variations in the insertion depths of AVBs in the vicinity of an unsupported U-

]

bend tube on the initiation of fluidelastic vibration.

4// 6 l

O I

s I

==

9,/,6

/

' RESULTS:

I

.~

ase n e

t 9

9 3

f

- - -__mm__

l i

't

}

g e

F BV O A Y ET LI BL I

A B IRA AT VS FIN N O

G I

SC S TE TI CESD F A FL L EE A D U EIHUT LP TFE G

C N EN HO INT C

I M

RN EO S E

T B

ES DH U T

R T OPD FEE DT S

R UN O TOP AIRTP A RU P ES PSN N

AI U i;

~

l1 l

.lll(

((l

-r I

I

.e

h. -..%

.g i

Test Stand Photo l

't e.

I l

I I

4

~ - =

-m-a.

.n, m

J i

I g\\

A~

$~

i 4

i i

Test Stand Photo 6

9 9

9 e

N

. _.. :: ::=._

~~ **m w-_________________________

E- -

~

se,

e e

6 4

d e n G

h...qo

~

mz1..... a,en,,e 3 o,

m.

4 e

4 e

9 e

O y

e O

O g!

e t

6 5

9 O

ae e

~ - -

j-

/

4_4 e.

l /

. (

O e

6 9

1 e

4

. ~I 4

~

FICURE 1 LDCAL TEDCITY PEAEING FACTOR IN U-SEND OF NORTE AIDIA 1 STEAM CENERATORS (TYPE I AND II ATS IllSEETION)

{

~

'.+

l-

'Ir f

I TTFE III S.S. 5 (RSC43. RSC54) a l

- & (18C25).

G,b,C

'~

f

/

G 9

(~

4-

unear R,ressi a f,1+a 20% Bok t

g

~ 20% +a ro% Top

{

1

... f.gf fg.,

~

1 Graph of Vibration Amplitude versus Flow Velocity t

l 1

L.

.......=....-..-..:.-

...e 4

e

Lmear krsed ~ 8% b 20"/, 84-T g

~ Bo'/o &O SO% Te9 t

e A hs.&

t

.. - s l

Graph of Vibration Amplitude versus Flow Velocity 5

~

=

e

_a 9L.

e i

q

.t.

m

D V

wwu vwvww __

0 COsWE.NO.. X 4 A.. m Jol.e,

.B.

P.

t

..s.

.s.

..y

_s..

.1

1... _.

. s.

.i

...;.......s..

.t.....

. s..

..s

.. s

......1....

.1..

i...

I

i..

e....

. I J.....

I 3

g.

r I

9

., f _i...

t

.I 1..

..z

... 4, 3,..

. r ;

J -...

f....

g l

9.

..a

,r i

~,

7 q

.4

\\

)

.... I 2

..:..: : l.

g...

.. _. _ 3 s.

s....

9 9

,.I i

a.

Graph of Vibration Amplitude 4

versus Flow Velocity F. _ _. '.

i

• t l

l l

1

_y.

}..

i t-t.s... :..

l k

i.

L...

i.....

i

.s.

.....a.

. ____.i...__..:..

1 i

.t.

...... t L

... t............ -...

...r.

.s....

i..

1 s,

.._ s.....J_

.a,

)

1..

.g i

M

.)

[--

i,;i.

p L

POINT. BEACH UNIT 2 EVALUATION TO ASSESS THE UNSUPPORTED U-BENDS REIATIVE TO THE FAILED TUBE AT NORTH ANNA UNIT 1, R9 C51 I

TO IDENTIFY TUBES THAT DO NOT HAVE STABILITY RATIOS LESS THAN'90% or NORTH ANNA UNIT 1, R9 C51, AS BEING TUBES Jt f RSSK TO EVALUATE THE APPARENT STRUCTURAL MARGIN OF TUBES THAT ARE NOT AT RISK COMPARED TO NORTH ANNA UNIT 1, R9 C51 Ag l

l l

1-e 9

I a.

CRITERIA FOR TUBE FATIGUE EVALUATION NORTH ANNA POINT BEACH L

lot S.R. REDUCTION CRITERIA UTILIIED UTILIIED O

pEFINITION OF AVB SUPPORT

[/

UTILIZATION OF FIDW PEAKING FACTORS i

l JAGNITUDE IDENTIFIED BY ANALYSIS,,, 4,6 N GNITUDE OBTAINED BY TEST 2 4c g,

e a.

POINT BEACH 2 i

EDDY CURRENT DATA No TUBES WITH WALL THINNING INDICATIONS AT AVBS I

e 2004 INSPECTION OF ROWS /TO p s

ov 1

TUBES WITHOUT AVB SUPPORT IN ROWS S TO 12 ARE DENTED

./

DATA OBTAINED To DEFINE AVB POSITIONS es t

~

8

~

l

99909 i

O [~~

~

09900 3

99999 1

00000 G9990 3

OOOOO i

SOOO 99900 5

99999 1

OOOO

-Q9990 99999 1

OOO :

99999 3

09000 1

000 99990 000 OOO eeees 00 GOO 99999 3

09 GOO 00099

@O000 000 e

99990' 09 OOO 3

5 099G0 3

000 1

OO I

99999 000 00 3

g 99999 3

900 1

GOO i

1 99999 1

999

@OO i

g g99990 OOO GOO i

s p

99999 090 5

e6800 1

2 89000 3

900 1

99e60 i

I

-99979 000 1

eseOO I

i 0G999 1

000 1

98900 3

j 99999 3

000 1

99000 5

g 09000 s

OOO 90eOO 99990 s

OSO 99000 i

ll 99000 5

900 5

99900 5

99999 1

---O g

99e00 3

QGOGO O :

990es 99999 i

99eOS I

90000

]?

}

9990G

]

99999 5

99900 OGOOO s

99999 eeees J

00000 1

99990 1

99990 7

i O n 99990 1

@eoOO 3

e 5

f __

i i

f_

i i

i-i

WeeeG i

G 09999 1

_GeeeG E

9000G i

e e e e eII eeeeO E

GGGGG U

e e e S ei s eeeee ese eeeeeli esees i

GGG :

j eeee_0 3 eeeeG E

GOO

)

e t e eB ee9GG 1

eeeGG eeeee n

eeeeG 1

eeeGG eeeee n

eeeeG eeeOO J

eeeeG i

e9990 1

eeeee r

)

eeeee eeeee l

seeee 3

m G e e e el :

etGO@

99999 eeeGe

?

Geese i

y eeeee-h-..e.

M-- -e

)

eeeeeli r

n eeeeS i

e 99999 eeeeG s

g g eeeeel 35 e e e e eli MG9 9 5

eeees i i

I 2

eeeeel GeeOO eeeee e e e e els GeeGe i

Geeee

?

G e e e ec, eeeee l

eeeee i 1

e e e e el t eeeOO g

eeeee i

g eeeeel s

eee9G

=

eeeee a

a eeeee:i eeeGG I

eeeeG i

eeeee n

eeeGG i

eeees i ll eeees i

eeeGO z

eeees

~

l GeeeG 3

eeeec i

eeeee eeGee n

GeGeG 1

eeteG i

1l l Il g

_eeeOO 88G99 Gee 90 3

l Ge@GG eeeee See@@

t OGGGG j eGeee l

seee@

T l

e 9

GeeeG. !

99900 3

900 e

l k

i f__

i

=

i i

=

i i

POINT BEACH 2 FLOW PEAKING FACTORS PEAKING FACTOR *

~

As ho d REFERENCE NORTH ANNA 1 R9C51 S.G. A - PT. SEACH e R12C2, R12C91, R11C2, R11C3, R11C91, R10C3, R10C4 e R11C4 S.G. B - PT.' BEACH e R12C2, R12C91, R11C2, R91C2 e R10C5 e R10C46, R10C47 o

• VAIITES BASED ON PEAKING REIATIVE TO UNIFORM R11 AVB INSERTION.

o J

4 i

l 1

D

RE B

M U-N N

M ULO C

S V

2 R

S 1

S IW Oka haih il

~

R E

B M

U N

L

. O C

SV O

ITAR 1

5 C

9 RAN

/

2 R

S 1

S IW e

0 e h e e,v I

....... ~.....

+

Point Beach 2 Evaluation Stress Ratio Method The stress ratio is used to provide a stress amplitude comparison of Point Beach 2 tubes with the failed tube of North Anns 1, Row 9 Column 51.

i si s t h

i=

0

\\

l

. ~..

Point Beach 2 Evaluation Stress ratio method (Cont'd) 4, p.

e

-___-___m__

)

1 V

E R

S 6

HTA

(

1 5

C 9

YR R

ATE A

I R

N P

~

O R /

P E

S 1

0 S

0HG I

N W l

i5E i

O i

ITAR S

SE RTS s

OFk aw l

l

l Ji i

J POINT MEN 2-fv4LUAT10N OF IRISUPPORTED U-8EOS 1918FRACTIONBEPE8DITI S.I.A 5.5.I IR FP BR*FP STRESS SR FP IReFP STRESS TUIE Mila MTIO RATIO MTIO TWE MTIO MTIO MTIO MTIO

.h $

Ao&

R12C2 1.13 0.40 R12C2 1.13 0.48 R12C91 1.13 0.48 R12C91 1.13 0.48 tilC2 0.83 0.M R11C2 0.83 0.M R!!C3 1.16 0.65 R11C91 0.83 0.M R11C4 1.13 0.76 RlE4 0.94 0.21 Riitti 4.83-0.M R10C5 0.93 0.57 g

RIE3 0.96 0.24 RlR90 0.96 0.24 RIK4 0.94 6.21 R9C3 0.70 0.00 1

RIK5 0.93 0.2 MC90 0.78 0.00 29C3 0.78 0.00 2002 0.77 0.M ROC 2 0.77 0.M MC91 0.77 0.M

~

R8C91 0.77 0.M 6

A STREE3 RATIO OF ( M = TO 1.018 ECEPTABLE g/ \\

.'I

\\ i MTE: RAT 105 ARE IN COMPMISON TO N.A.1 RfC51 9+.

\\

\\(O 1

i

._ _______ _________________ a

, y'I' N

.;p,. [ }

j

, '9 l

,r

'3 1

/

,.3 PointBeach 2 Evaluation c

ql n

u

.;s, 3

e

<./y j

e.

Current Fatigue Usage,

i t. '

1

~b j

• Foralltubee meeting t 10% cr{ttKa, the maximumbress is

[

less than 4.0 KSI.

/

\\

The maximum shess ratio for an unsupported tube is 0.76 in

(

Row 11 resulting in a maximum stress ofless than...;

y!

,u 4.0 (0.76) = 3.,04 KSI

{~

..n The cumulative fatigue usege Vov Als worst case is 0.CB1,l>5 y. \\

',[

V taking n!I cycles at the highest struss.,

lv.

b);

p. ' ' '

~jy f

t

. Normalized.

4 Fuel Stability Alternating 4, Cy_cles _,3,5 s

Cycle

. Ratio Stress

(!;,0sys st{ 'J m,L \\

1,(i,:n

> 288 6

13 1.0 1.0

\\

}/l 577 11,12 0.989 0.936 10 0.987 0.924 416 j

v 7,8 0.985

'O.913

$15 O.891

!'c 613 l';

i 5,6 0.981 3,9 0.977 ';,

0.B?) [y 570

. b ',~ a 1,4 0969.

0.828 ; ' '

783 h'a i

c 2

0.966 '

O.813

\\

344 L'

w-X(

,1. s,c \\ '

'l

}-

Tots! Cycles s

,1,

/,

',}

g6 ts.

(

)

i

\\-

i.

).

/

___C.________________.___

.2._

j.

(t

'd-POINT BEACH UNIT 2 EVALUATION

[w.

SUMMARY

AND CONCLUSIONS.

l s.

EDDY fMP. RENT INSPECTION e NO Fi1L THINNING INDICATIONS A*.' AVBS (1004' INSPECTION ROWS a TO 12) s

-. INDICATES IDW LIKELIEOOD OF.TIMIDELASTICALLY UNSTABLE TURES.

u, i

e TURES IN*A0WS S-12 ARE DENIED.

s DATA 0BTAINED FOR AVB POSITION 3 MINIMAL INTERFERENCE FROM DEPOSITS

=

AVP POSITIONS e R0W 11 SUPPORTED EXCEPT FOR A FEW PERIPHERAL COLUMNS'

'i e MOST ROW 10 !;TJBE3.8UPPORTED e AVB PENETRATION TO ROW 8

'ATECS ANALYSIS TRENDS e' N0 DEL 44 TENDS TOWARD IDWER VEIDCITIES AT INNER R0WS COMPARED To MODEL 51

.- (

e' POINT B1ACH VOID FRACTIONS IDWER TNAN NORTH ANNA

)

[

1 t

s.

u POINT' BEACH 11 NIT S EVA2ATION

SUMMARY

AND CONCLUSIONS a

a TUBE VIBRATION ASSESSMENT 1

e; GENERAL NODEL 44 VS. MODEL S1' COMPARISON MODEL 44 TURE RADIUS, FREQUENCY FOR RON 10 APPROXIMATELY

<=

' SQUIVALENT TO RON 8 FOR MODEL S1 e ROWS & 9 ASSESSMENT ACCEPTABLE WITH LARGE MARGINS DDE TO INCREASED TUBE STIFFNESS e ROW 10 ASSESSMENT IAWER VELOCITIES AND VOID FRACTIONS THAN NORTH ANNA R9C51 ACCEPTABLE WITHOUT AVB SUPPORT e

GEPTRALLY ACCEPTABLE EVEN WITH IDCAL FIDW PEARING AS HIGH I

AS' NORTH ANNA R9C51 ROWS 11 AND 12 ANSESSMENT 3

e TOTAL OP 5 UNSUPPORTED TURES IN ROW 11 AND 4 IN ROW 12 SUMMED OVER DOTH STEAM GENERATORS

' ONLY PERIPMERAL TOBES WITH NEGLIGIBLE POTENTIAL FOR IDEAL FIDW PEAKING e

CVERALL ASSESSMENT r

MAXIMUM S.R. REIATIVE TO N. ANNA R9CSI = 0.88 NAXIMUM STRESS RATIO REIATIVE TO N. ANNA R9C51 AT 0.8

• 8.R. = 0.78 MAXIMUM STRESS AMPLITUDE OF < 4 RSI WOULD NOT LEAD TO

=

t FATIGUE FAILURE IN 40 YEAR PLANT LIFE CONCESSIONS v

e POINT BEACE UNIT S ACCEPTABLE RELATIVE TO TUBE FATIGUE AT TOP TSP e NO MODIFICATION OR PREVENTATIVE TURE P2 0GING IS REQUIRED s

'T