ML20133D366

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Rev 1 to Evaluation & Disposition of Flaws at Quad-Cities Nuclear Power Plant Unit 2
ML20133D366
Person / Time
Site: Quad Cities 
Issue date: 07/15/1985
From: Buchholz R, Froehlich C, Wenner T
NUTECH ENGINEERS, INC.
To:
Shared Package
ML20133D351 List:
References
0397K, 397K, CEC-20-013, CEC-20-013-R01, CEC-20-13, CEC-20-13-R1, NUDOCS 8510090042
Download: ML20133D366 (53)
v • d • e


Text

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ATTACHbENT 2 EVALUATION AND DISPOSITION OF FLAWS AT QUAD CITIES UNIT 2 0397K B510090042 850722 PDR ADOCK 05000265 G

PDR

C EC-20-013 Revision 1 July 1985 CEC 020.0202 EVALUATION AND DISPOSITION OF FLAWS AT QUAD CITIES NUCLEAR POWER PLANT UNIT 2 i

Prepared for:

Commonwealth Edison Company Prepared by:

NUTECH Engineers San Jose, California a

Prepared by:

Issued by:

d447/. Lag

& z 7/. # m a,-

P C.

H.

Froehlich, P.E.

R.

H. Buchholz Project Engineer Project Manager Approved by:

O 1

7-/7-85 dL Da te:

A-

.)

T. J. We nne r,

P.E.

Engineering Manager nut.eSb u

REVISION CONTROL SHEET TITLE: Evaluation and Disposition DOCUMENT FILE NUMBER: CEC 020.0202 of Flaws at Quad Cities Nuclear Power Plant Unit 2 C. H. Froehlich, P.E./ Staff Engineer CD

. NAME / TITLE INITIALS

/O T. J. Wenner, P.E./ Engineering Manager 44 '. /., C ' F

/ i.-

N AME / TITLE

--INITI A LS M. E. Kleinsmith/ Consultant I

'[f/('7<

N AMEl TITLE INITI A LS H. L. Gus':in, P.E./ Principal Engineer l

NAME/ TITLE INITIALS N AME / TITLE INITIALS AFFECTED 00C PREPARED ACCURACY CRITERIA REMARKS P

PAGE(S)

REV CY 10 ATE CHECK 8Y / OATE CHECK BY / DATE Oj-[~. t o rf f h69 4-/0# ((j

(,-19.gI i-vii 0

6-ei-tr 1.1 -

1.8 2.1 -

2.3 3.1 -

g 3.5 a

4.1 -

4.9 5.1 -

5.17 6.1 F

7,1 _

y.

y 7,

C., c J Qgy(

,./7.g ))/j 6-/9 8f 7.3 V

4-It-1f lii i

cM91li1lss kc-/c 7 -i? a'; g1 J.,7-df Deleted Weld 02BS-512.

1.1 General editorial

1. 2 revisions.

1.5 4.5 5.4 5.5 5.6 If 5.17 V

1P 6.1 if ClM4 1)1ls5 'MC-A IJ-o?

17-/7-6 ii VII Pact 0F cEr 3,s.t.t REV t

CERTIFICATION BY REGISTERED PROFESSIONAL ENGINEER I hereby certify that this document and the calculations con-tained herein were prepared under my direct supervision, or reviewed by me, and to the best of my knowledge are correct and complete.

I further certify that, to the best of my knowledge design margins required by the original Code of Construction have 7'

not been reduced as a result of the repair addressed herein.

I IL am a duly Registered Professional Engineer under the laws of the State of Illinois and am competent to review this document.

i d,

P Ce rtified by:

f i

yt

/

62 39110

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- *f P

$t, ;W ss i

ENGINEER OF H.

L.

Gustin, P.E.

Registered Professional Eng.neer

,g State of Illinois 7-17,8 f Registration No. 062-039110 Red l A 19, I4 W Date:

I C EC-2 0-013 iii Revision 1 gg

TABLE OF CONTENTS Page LIST OF TABLES v

LIST OF FIGURES vii

1.0 INTRODUCTION

1.1 2.0 REPAIR DESCRIPTION 2.1 3.0.

EVALUATION CRITERIA 3.1 3.1 Flawed Pipe Analysis 3.1 3.2 Reinforcement Weld Overlay Repair Design 3.2 i I.

3.3 Residual Stress Improvement Weld 3.4 l'

Overlay Repair Design and Analysis 4.0 APPLIED LOADS AND RESIDUAL STRESSES 4.1 4.1 Mechanica l, Internal Pressure and 4.1 Thermal Expansion Loads y

^

4.2 Weld Overlay Shrinkage Loads 4.2 4.3 Weld Residual Stresses 4.2 5.0 EVALUATION METHODS AND RESULTS 5.1 5.1 Flawed Pipe Analysis 5.1 5.2 Reinforcement Weld. Overlay Repair Design 5.2 5.3 Residual-Stress Improvement Weld Overlay 5.3

~

L*

Repair Design and Analysis 6.0

SUMMARY

AND CONCLUSIONS 6.1

-l*

u

7.0 REFERENCES

7.1 F

CEC-20-013 iv Revision 1 g{

I i

.r

LIST OF TABLES Num be r Title Page 1.0-1 Location and Descri) tion - Flaws Overlay-1.3 Repaired Fall 1983 Outage - Quad Cities

. Unit 2 1.0-2 Comparison and Description - Flaws IHSI -

1.4 Mitigated Fall 198 3/ Overlay-Repaired Spring 1985 - Quad Cities Unit 2 1.0-3 Comparison ar.d Description - Flaws Requiring 1.5 IHSI Mitigation Only - Quad Cities Unit 2 3.2-1 Leakage Barrier Repair Criteria for 3.5 Axial Flaws L

4.1-1

~ Re inforcement Overlay Repair De sign Loads 4.3

'j.

4.1-2 Residual Stress Improvement Overlay Repair 4.4 De sign Loals P

4.1-3 LIHSI-Mitigated Flawed Weld Evaluation Loads 4.5 4.2-1 Weld Overlay Shrinkage Measurements 4.6 5.1-1 Pipe and Flaw Geome tt '.c De tails -

5.4 Circumferentially Flawed IHSI-Mitigated Welds 5.1-2 Applied Stresses - Circumf erentially 5.5 d_

Flawed IHSI-Mitigated Welds 5.1-3 Predicted End-of-Cycle vs. Allowable 5.6

~~

Flaw Depths - Circumferentially Flawed 3

IHSI-Mi tigated Welds 5.2-1 Pipe and Flaw Geome tric De tails -

5.7 Circumferentially Flawed Reinforcement Overlay-Repaired Welds 5.2-2 Applied Stresses - Circumferentially 5.8 Flawed Reinforcement Overlay-Repaired Welds 5.2-3 Applied vs. Allowable Stress Ratios -

5.9 Circumf erentially Flawed Reinforcement Overlay-Repaired Welds C EC-2 0-013 v

Revision 1 0

LIST OF TABLES (Co nclud ed) i Number Title Page

)

5.2-4 Pipe and Flaw Geometric De tails - Axially 5.10 Flawed Reinforcement Overlay-Repaired Walds 5.2-5 Applied vs. Allowable Stress Ra tios - Axially 5.11 Flawed Reinforcement Overlay-Repaired Welds 5.3-1 Pipe and Flaw Geometric De tails -

5.13 Circumferential1y Flawed Residual Stress l

Improvement Overlay-Repaired Welds 5.3-2 Applied Stresses - Circumferentially 5.14 Flawed Residual Stress Improvement Overlay-Repaired Welds 5.3-3 Predicted End-of-Cycle vs. Allowable Flaw 5.15 7

Depths - Circumferentially Flawed Residual Stress Improvement Overlay-Repaired Welds w,

L l

('

\\b r.

F C EC-2 0-013 vi Revision 1

@k

e LIST OF FIGURES Num be r Title Page 1.0-l' Ouad Cities Unit 2 Reactor Recirculation 1.6 Piping Jet Pump Risers 1.0-2 Quad Cities Unit 2 Reactor Recirculation 1.7 Piping "A" Loop 1.0-3 Quad Cities Unit 2 Reactor Recirculation 1.8-Piping "B"

Loop and Shut Down Cooling 2.0-1 We ld Overlay Re pair Dimensions 2.3 4.3-1 Pre-and Post-IHSI Through-Wall Residual 4.7 St ress Distributions for 12" NPS Pipe 4.3-2 Pre-and Post-IHSI Through-Wall Residual 4.8 Stress Distributions for 20" a nd 2 2" N PS Pipes 4.3-3 Pre-and Post-IHSI Through-Wall Re sidual 4.9 Stress Distributions for 28" NPS Pipe 5.2-1 Source Equations for Allowable End-of-5.12 Evaluation Period Flaw Depth-to-Thickness Ratios for Circumf erential Flaws 5.3-1 Modified Axial Residual Stress Distribution 5.16 for Weld 10S-F5 5.3-2 Modified Axial Residual Stress Distribution 5.17 p

for Weld 02AS-S4 1

.l?

C EC-20-013 vii Revision 1 Q

r--

s

1.0 INTRODUCTION

This report sunmarizes analyses performed by NUTECl! to evaluate flaw indications in the Reactor Recirculation and Shut Dov. Cooling systems at Commonwealth Edison's Quad Cities Nuclear Power Plant Unit 2.

Ultrasonic (UT) examination of welds in these systems identified flaws judged to be intergranular stress corrosion cracking J'

(IGSCC) in the vicinity of a total of twenty-four L

i welds.

Twenty-two flawed welds were identified during l

the Fall 1983 outage.

One of these welds (12S-S2 7) was removed and replaced (spool piece replacement).

Two flawed welds were identified during the Spring 1985 outage.

The locations of these welds are shown in Figures 1.0-1 through 1.0-3.

L In addition to the twenty-two flawed welds identified e,

during the Fall 1983 outage, IGSCC was originally thought to have occurred at two other welds.

At Weld 0 2M-F7, a lack-of-fusion type of flaw was traced back to this weld's original construction.

At Weld 0 2BS-S12, a geometric discontinuity was identified through the use of a core sample.

t Tables 1.0-1 through 1.0-3 present descriptions of the IGSCC flaw indications at Quad Cities Unit 2.

Table 1.0-1 describes flaws in the nine welds which were C E C-20-013 1.1 QQfQCb Revision 1

i overlay tepaired during the Fall 1983 outage.

Ta ble

~1.0-2 d scribes flaws in four welds which were shown to 9

be acceptable with only induction heating stress improvement (IHSI) mitigation during the Fall 1983 outage.

In addition,- Weld 02E-F6A, which showed no reportable indication in 1983, is listed in this table.

All of the welds listed in Table 1.0-2 were overlay repaired during the Spring 1985 outage.

Table 1.0-3

[

describes flaws in nine welds which were shown to be

(-

acceptable with only IHSI mitigation during the Fall 1983 outage.

The design of weld overlay repairs and the

,1 analysis of IHSI-mitigated weld flaws discovered during.

FT-the Fall 1983 outage at Quad Cities Unit 2 are described in NUTECH Report COM-75-002 ( Ref erence 1).

The purpose of this report is to demonstrate that the original design margins of safety for the flawed welds I'

at Quad Cities Unit 2 have not been degraded.

Se ction 1.

2.0 presents a general description of the overlay re-p.

pairs performed at Quad Cities Unit 2 during the Fall 1983 and Spring 1985 outages.

Sections 3.0 and 4.0 present the evaluation criteria and loads used.in the analysis of overlay-repaired and IHSI-mitigated weld flaws.

Section 5.0 presents the evaluation methods and results.

Sections 6.0 and 7.0 present a summary of conclusions and the references used in the evaluation.

C EC-20-013 1.2 Revision 1

-1' 6.& - X

']'

w R

F9

~i?

EM O f3 Ta ble 1.0-1

r. w LOCATION AND DESCRIPTION FLAWS OVERLAY-REPAIRED PALL 198 3 OUT AG E QUAD CITIES UNIT 2 Wold ID Pipe Size Configuration De sc r i pt ion I

02 D-F6 12" P-S 8" x 80% Circ. (P.S.)

0 2 F-F6 12" P-P 360* Int. x 151 Cire. (Upstream)

Y w

02G-S1 12" P-E 2-1/4" x 32% Circ. (P.S.)

02J-F6 12" P-S 15" x 151 Cire. (P.S.)

l 0 2A S-S9 28" E-V 1/2" x 10% Ax ial (E.S.)

1" x 91 Cire. (E.S.)

11" x 23% Circ. (E.S.)

12" x 13% Cire. (E.S.)

02DS-S3 28" P-E 12" Int. x 401 Cire. (E.S.)

0 2B S-P7 28" P-V 360* Int. x 16% Ci re. (P.S.)

0 2 B D-S6 28" P-E 17" x 39% Circ. (E.S.)

1-1/4" x 64% Axial (E.S.)

10S-F1 20" P-T 6" x lin Circ. (P.S.)

$,+

Y' M.V

'3 C

1 4

l l

mn t

O to 4O r

P-a

$. o" Table 1. 0 -2 i

oe

'po i

V' F* u COMPARISON AND DESRIPTION FLAWS Ills I-MITIGATED FALI. 1983/ OVERLAY-REPAIRED SPRING 1985 OUAD CITIES UNIT 2' Fall 1983 Ou tage Spring 1985 Outage Weld ID Pipe Size Configuration Indications Indications l

02E-F6A 12" P-P No reportal>le indications 1" x 181 Ci rc. (Upstream) l w/1/4" x lit Axial F'

1/2" x 141 Ci rc. (Up stream) j w/0.2" x 13% Axial u

02M-S3 12" P-E l-1/2" x 301 Cire. (E.S.)

3-1/2 x 50% Cire. (E.3.)

1" x 13% Circ. (P.S.)

2" x 651 Circ. (P.S.)

7/8" x 701 Axial (P.S.)

02M-F7 12" P-S 4-1/2" lack of fusion 7-1/2" x 1001 Cire. (S.S.)

0 2A S-S4 28" P-E 27" Total x 13% Ci re.

(E.S.)*

58" x 20% Max. Circ. (E.S.)

4" x 111 Cire. (P.S.)

i 10S-F5 20" P-V 3-1/2" x 18% Ci re. (P.S.)

9" x lit Ci rc. (P.S.)

8" x 12% Circ. (P.S.)

10" x 17% Circ. (P.S.)

3" x 13% Cire. (P.S.)

Portion of length not reported in 1983.

II C:

[.

3 C.. s9 t

'T M

C l

l

-wo Ta ble 1.0-3 r-e M N e-o Og COMPARISON AND DESCRIPTION g, [

FLAWS RE0nIRING IHSI MITICATION ONI.Y C. LAD CITIES UNIT 2 Fall 1983 Ou tage Spring 1985 Outage l

Weld I D.

Pipe Size Configuration De sc r i pt ion Description l

0 2 D-S 3 12" P-E 1/2" x 25% Ci re. (P.S.)

1/2" x 26-28% Circ. (P.S.)

02M-S4 12" P-E 1/2" x 91 Circ. (E.S.)

1/2" x 151 Circ. (E.S.)

02A-S10 22" P-E C 4" x 26% Circ. (EC.S.)

4" x 161 Cire. (EC.S.)

F 020-S9 22" P-EC 17" Total x 151 Max. Circ.

17" Total x 141 Max. Circ.

v' (EC.S.)

(EC.S.)

02AS-S6 28' P-P 7-1/2" x 21% Circ.

8" x 18% Circ. (Upst ream )

(Up st rema) 02AS-S12 28" P-E 8" x 14% Circ. (P.S.)

d" x 15% Circ. ( P.S. )

4" x 111 Cire.

(P.S.)*

6-1/;" x 51 Ci re. (P.S.)

1" x 81 Cire. (E.S.)

2-1/." x 15% Circ. (E.S.)

2" x 91 Ci re. (E.S.)

0 2AS-F14 28" P-E 4 3" x 20% Cire. (P.S.)

43" x 131 Max. Circ. (P.S.)

Spot x 30% Circ. (P.S.)

0 2AD-F12 28" P-P 24" Total x 10% Cire.

1" x 16% Cire. (P.S.)

E (P.S.)

02BS-F14 28" P-E 5-l/4" Total x 18% Circ.

1" x 101 Cire. (P.S.) w/I.D.

(P.S.)

Geometry pMp Not reported in 1983.

h 02G 53 g N28

[.

m 5

35*

M 305" N7C

~__

021F6 5

2 i.o I

  • l 02F F6 ;

- rw

(

N2H I

245" N

~

I 02M.53 N7, 185*

., 020.S3 /

02M-54 w

/'

W j

1

/t See Figure 1, o 1.0-2 FCEC85 03-04 F

Figu re 1.0-1 OUAD CITIES UNIT 2 REACTOR RECIRCULATION PIPING JET PUMP RISERS (Reference 2)

C EC-20-013 1.6 OUf.

Revision 1 w.

o f-hSeeFigure

1. 0-1 N1A 155' 02AS.54 f

l i

02AS56 J

9 9

/

/

H 02AS-59 Y

02 AS-512 d

02AO F12 A

/

j't 02ASFra L)

FCEC85.03-02 i

lt Figure 1.0-2 QUAD CITIES UNIT 2 REACTOR RECIRCULATION PIPING "A"

LOOP (Reference 2) 1.7 C EC-20-013 Revision 1 g{

1 I

1 I

@SeeFigure 1.0-1 N1B

/

105-F5 /

c O

10ST1 i L 0285.F 7 n

=;

M 0280 S6 - -

7 28S-S12 0

b c 3 i.

- j' 02sS Fi4 F CE C85.0341 Fr gu re 1.0-3 QUAD CITIES UNIT 2 REACTOR RECIRCULATION PIPING "B"

LOOP AND SHUT DCWN COOLING (References 2 and 3) s C EC-20-013 1.8 Revision 1 gg 1

iy*w r

-s-g

+,.-+y---

.-g r----w.w-,w--e--r-gcw---.

wa-%--

2.0 REPAIR DESCRIPTION The welds listed in Tables 1.0-1 and 1.0-2 have been repaired by applying additional " cast-in-place" pipe -

wall thickness with weld metal deposited 360' around and

.to either side'of the existing weld as shown in Figure 2.0-1.

A comparison of design and as-built inf orma tion for the overlays is also given in Figure 2.0-1.

The r

weld-deposited band provides additional wall thickness 1

to restore the original design safety margins.

In add i-i

}'

tion, the welding process produces a f avorable compres-as sive residual stress pattern on the inside portion of

e..

the pipe wall, which prevents f urther IGSCC growth and inhibits initiation of new flaws.

The deposited weld metal is Type 308L which is resistant to IGSCC propa-l

{-

gation because of its duplex (austenitic-ferrite) 4 i

s tructure.

Delta f errite measurements of the first layer of each weld overlay were performed to evaluate-7 i>

the effects of base metal dilution of the weld metal.

All delta ferrite measurements taken of the first over-lay layer were greater than 7.5 FN, except for the measurement at one position on weld 10S-FS, where the delta ferrite measurement was reported as SFN.

Th is is

~

judged to be high enough to prevent IGSCC propagation into the overlay metal.

I C EC-20-013 2.1 Revision'l' g

-Nondestructive examinations of each weld overlay consi_sted of:

1.

Delta ferrite content measurement of the first overlay layer.

2.

Enhanced visual examination (amplified acceptance criteria) of the first weld overlay layer for any evidence of previously undetected steam blow-outs.

e, 3.

Surface examination of the completed weld overlay

'~

>J by the liquid penetrant examination technique, in 0

accordance with ASME Section XI ( Reference 4).

i 4.

Ultrasonic examination of the completed weld overlay to demonstrate adequate bonding with the L

base metal, n

4

. l}

i 4

1 4

C EC-20-013 2.2 Rovision 1 g

i

L l

TYPE 308L CVIPlAY s

I

-e 4s ( YP)7 o g g a

\\\\ \\\\\\l/ /

ta I

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8 TYPE 304 TYPE 304 PATENT APPLIED FOR I

l Actual iJ Design Overlay Actual Overlay Design Overlay Overlay Thickness, t Weld ID Lenoth, L Lenoth, L Th ic k n es s, t Upstream / Downstream O

02D-F6 3.75" 3.875"

.25"

.20"

.270"/.313" 02G-S3 4.50" 4.5*

.20"

.314"/.276" 02J-F6 3.75" 3.75"

.20"

.309"/.339" 02AS-59 2.50" 2.80"

.125" NA/.348" 0 2BS-S 3 4.50" 4.62"

.20"

.285"/.362"

,j 02BS-F7 4.50" 5.54"

.20" NA/.287" 02BD-S6 6.50" 6.56"

.350"

.462"/.550" W

105-F1 2.25" 3.625"

.20" NA/.329" d

02E-F6A 4.50" 4.5"

.208*

.22"/.201" 02M-53 4.0" 5.0"

.208"

.253"/.256" ji 0 2tt-F7 3.0" 3.44"

.206"

.242"/.284" 105-F5 2.5" 2.5" Two Layers NA/.156" 0 2AS-S 4 7.0" 8.0" Two Layers

.173"/.181"

  • Readings could not be taken due to geometry.

Figure 2.0-1 WELD OVERLAY REPAIR DIMENSIONS C E C-20-013 2.3 mt.

h Revision 1

I:

'o L

3.0 EVALUATION CRITERIA j

This section describes the criteria used to evaluate the acceptability of the overlay-repaired and IHSI-mitigated weld flaws at Quad Cities Unit 2.

3.1 Flawed Pipe Analysis NUTECH Report COM-75-002 (Re ference 1) discusses the evaluation approach and criteria used to justify

},

operation of Quad Cities Unit 2 for the fuel cycle i

between the Fall 1983 and Spring 1985 outages with IHSI

~

mitigation of the -flawed welds presented in Tables 1.0-2

.and 1.0-3.

The following criteria were used by NUTECH to justify an additional fuel cycle of operation:

L 1.

The beginning-of-cycle flaw size used in the analysis was the as-measured flaw size determined during the Spring 1985 outage ultrasonic e xami na tion.

2.

The flaw growth evaluation is based upon a con-servative crack growth law derived from NUREG-1061 (Re ference 5) crack growth data, using a combi-nation of dead weight, internal pressure, weld overlay shrinkage, and thermal expansion loads.

l'Si'f; tilitgligl)

I:

3.-

Calculation of IGSCC flaw growth was. initially based upon conservative through-wall mitigated residual stress distributions.

The final I

evaluation took no credit for f avorable residual.

-stress distributions.

4.

The predicted end-of-cycle flaw size was compared to 2/3 of the ASf1E Section XI (Reference 4) Table F

IWB-3641-1 allowable. flaw depth values for a

'l.

combination of dead weight, internal pressure, and

,c.

selsnic loads as required by Generic Letter 84-11 j-(Reference 6).

D 3.2 Reinforcement Weld Overlay Repair De sign NUTECH Report COM-75-002 discusses the evaluation and design criteria used for the flawed welds which were overlay repaired during the Fall 1983 outage.

The following criteria were used by NUTECH to justify an additional fuel cycle of operation:

1.

For nominal pipe sizes less than or equal to 12",

an IGSCC-induced flaw was assened to have a 100%

through-wall-by-as-measured length geometry.

2.

For nominal pipe sizes greater than 12", an IGSCC-induced flaw was assumed to have a depth of twice C EC-2 0-013 3.2 Revision 1 gf

the maximum ultrasonically measured flaw depth over its as-measured length.

t 3.

For flaws assumed to have a 100% through-wall depth, a bounding fatigue-induced flaw growth of 0.0 10" into the overlay material was used based upon the NUTECH design report for recirculation safe end and elbow repairs at Monticello (Re fer-

. r-ence 7).

l 4.

The weld overlay repair strength for a combination J.

of dead weight, internal pressure, and seismic D

loads was compared to the net section collapse criteria of ASME Section XI (Reference 4) Paragraph IWB-3 6 40.

i b;

These criteria were also used to design overlays for c,

L Welds 02E-F6A, 02M-S3 and 0 2M-F7 repaired during the i

Spring 1985 outage.

l.

All welds with axial flaws were overlay repaired during i

the Fall 1983 and Spring 1985 outages.

The following criteria were used to evaluate each repair l

I i

i 1.

An IGSCC-induced axial flaw was assumed to have a i

100% through-wall-by-as-measured length geometry.

1 e

C EC-2 0-013 3.3 Revision 1

@{

2.

The weld overlay repair was compared to the leakage barrier criteria presented in Table 3.2-1 from NUTECH Report COM-76-001 (Re ference 8).

3.3 Residual Stress Improvement Weld Overlay Repair Design a nd An aly sis NUTECH Report CCM-75-002 presents the analytical results r-1' that justify the operation of Quad Cities Unit 2 during its last f uel cycle with flawed Welds 0 2AS-S4 and 10S-FS which were IHSI-mitigated during the Fall 1983 outage.

(*

A comparison of the ultrasonic examination results for these welds from the Fall 1983 and Spring 1985 outages as shown in Table 1.0-2 reveals apparent increases in flaw length and/or depth.

As a result, overlay repairs

,1 were applied to these welds which produce through-wall residual stress distributions that assure compliance with the Section 3.1 flawed pipe analy sis requirements.

C EC 013 3.4

[](jfjgj}f}

Revision 1

Table 3.2-1 LEAKAGE BARRIER REPAIR CRITERIA FOR AXIAL FLAWS (Reference 8)

NONDIMENSIONAL PLAW LENGTH STR ESS 4//TT MAT 10 0.00 0.25 0.50 1.00 2.00 s

3. 0.40 z

,a 0.50 z

0.60 0.70 z

0.80

=

0.90 z

0.95

=

l 1.00

  • LEAK BARRIER ONLY REQUIRED

'E STRESS RATIC = P0 / 2 T Sm I

i P = MAXIMUM PRESSURE FOR NORMAL OPERATING CONDITIONS l

0 = NOMINAL QUT310E DIAMETER OF THE PfPE

[

T = NOMINAL THICKNESS 4 = ENO.CP. EVALUATION PERl00 FLAW LENGTH R = NOMINAL RA01US OF THE PIPE l

1 l

i I

C EC-2 0-013 3.5

4.0 APPLIED LOADS AND RESIDUAL STRESSES The loads considered in the strength evaluation of the overlay-repaired and IHSI-mitigated flawed welds in-cluded dead weight and seismic mechanical loads, and internal pressure.

The loads and stresses considered in the crack growth evaluation of flawed welds included mechanical loads, internal pressure, differential thermal expansion loads, weld overlay shrinkage loads, and welding residual stresses.

This section presents-the loads and stresses used to evaluate the accepta-a bility of the overlay-repaired and IHSI-mitigated weld r-flaws at Quad Cities Unit 2.

4.1 Mechanical, Internal Pressure, and Thermal Expansion Leads J

P9 The internal pressure values used to evaluate the overlay-repaired and IHSI-mitigated weld flaws were obtained f rom NUTECH Report COM-57-003 (Re forence 9).

The dead weight, seismic, and thermal expansion loads were obtained f rom the EDS computer rund for the IE Bulletin 79-14 Reactor Recirculation and Shut Down Cooling system analy ses (Pe forence 10).

Ta bles 4.1-1 through 4.1-3 summarize the mechanical, internal pres-and thermal expansion loads used to evaluate

sure, the Quad Cities Unit 2 flawed welds.

CEC-20-013 4.1 r1 Lit.Ep,s;,t]

4.2 Weld Overlay Shrinkaqe Loads The crack growth evaluation of flawed welds included loads caused by axial pipe shrinkage at overlay repaired welds.

These loads were derived using NUTECH's PISTAR computer program ( Reference 11) for the overlay axial shrinkages presented in Table 4.2-1.

Ta ble 4.1-3 summarizes these loads for the Quad Cities Unit 2 flawed weld evaluation.

A 4.3 Wold Residual Stresses U

Figures 4.3-1 through 4.3-3 present the through-wall welding residual stress distributions used in the crack growth evaluation for welds that required IHSI miti-gation only.

These figures come from EPRI Document NP-2 662-LD (Pe f orence 12).

C EC-2 0-013 4.2

[](jfjg(( }

Revision 1

'I 6

w L

1 C

I.

< r1 w a u DJ eo oa U [$

Ta ble 4.1-1 eeo REINFORCEMENT OVERLAY REPAIR DESIGN IDADS Internal Dead Weight Thermal Expansion Seismic Pre,ssure F

M F

M F

M Weld ID

_ (psil (lbs.)

(in-lbs.)

(ths.)

(in-lbs.)

(Ibs.)

(in-lbs.)

0 2 D-F6 1,250 6,177 19,793 6,205 135,917 3,381 211,012 02F-F6 1,250 977 12,679 11,627 255,142 4,062 222,594 f.

0 2G-S 3 1,250 24 6,567 460 228,237 500 11,306 02J-F6 1,250 2,520 12,476 1,199 34,029 1,627 218,610 02AS-59 1,150 5,652 147,988 2,457 320,722 3,011 81,929 02ns-S3 1,150 2,927 29,150 9,939 2,908,877 5,882 107,607 0 2B S-F7 1,150 6,728 154,347 9,754 1,487,493 746 256,182 02B D-56 1,250 1,361 6,493 9,754 1,238,698 3,048 349,021 IQS-F1 1,250 455 443,916 6,612 2,553,059 1,981 729,348 02E-F6A 1,250 1,176 14,977 1,955 126,452 6,739 203,037 02M-S3 1,250 524 75,174 289 23,543 366 10,519 02M-F7 1,250 4,749 40,230 2,243 33,235 1,935 199,289 mtes:

g e-1.

F= applied amial force.

og bh 2.

M =

applied resultant sunme n t.

sc>

27 l

7

~'

i 6.

~

l mn o rt

<n v-8 m na no oe ao r.[

Table 4.1-2 RESIDE!AL STRESS IMPRGVEMENT OVERLAY REPAIR DESIGN IDADS Internal Dead Weight Thermal Expansion Seismic Pressure F

M F

M P

M Weld ID (psi)

(Ibs.)

(in-lbs.)

(lbs.)

(in-lbs.)

(ths.)

( i n-l bs. )

0 2AS-S 4 1,150 5.819 63,893 2,457 116,575 5,803 120,775

.s.

105-FS 1,250 398 144,315 37,410 2,698,457 1,061 163,023 raotes:

1.

F = applied axial force.

2.

M=

applied resultant moment.

)

C:

to 17

'u a-a L.

7 6, _.

7

'n n cn

<n ra au ro O a 3[1 Ta ble 4.1-3 ww Ills I-M ITI GATED FI. AWED WELD EVALUATION LOADS Internal Dead Weight Thermal Expansion Overlay Shrinkage Seismic Pressure F

M F

M P

M P

M We lit ID (psil (1bs.)

(in-lbs.)

(1bs.)

(in-lbs.)

(Ibs.)

fin-lbs.)

(1bs.)

(in-lbs.)

0 2 D-5 3 1,250 325 47,013 495 128,910 987 77,761 323 131,212 4

un 02M-54 1,250 6,549 37,871 2,243 15,259 36,662 273,788 2,029 83,395 0 2A-S10 1,250 (1)

(1) 0 0

0 0

(1)

(1) 02D-59 1,250 (1)

(1) 0 0

0 0

(1)

(1) 0 2AS-56 1,150 24,501 109,578 2,457 247,400 170 55,619 5,186 363,720 02AS-512 1.150 536 34,611 261 293,297 249 38,113 5,277 127,384 0 2A S-F14 1,150 536 36,643 261 270,1 35 249 33,553 5,277 125,255 0 2 A D-F12 1,250 442 28,365 571 170,731 179 19,349 5,342 709,495 0 2D S-F14 1,150 1,261 50,587 2,505 658,719 948 99,522 1,683 125,833 Notes:

1.

Negligible sagnitwie.

l

.P4*

2.

F= applied axial force.

d)

D 3.

M =

applie1 resultant m. m nt.

Ta ble 4. 2-1 WELD OVERLAY SHRINKAGE MEASUREMENTS Axial Shrinkage Weld ID (in.)

0 2 D-F6 0.140 0 2 F-F6 0.230 0 2G-S 3 0.230 0 2 J-F6 0.176 0 2A S-S9 0.020 0 2DS-S3 0.041

,j 0 2B S-F7 0.0 19 0280-S6 0.031 10S-F1 0.040 0 2 C-F6A 0.229 0 2M-S 3 0.204 0 2M-F7 0.150 0 2A S-S 4 0.038 ul 10S-F5 0.049 1

I' CEC-20-013 4.6 Rovision 1 nutgg.t!

{

i M

r M Ps W Pe 300 2c )

e00 0

00 0 200 300 300 200 10 0 0

10 0 200 300 TER SunfACE' 06-06-

,, g

\\

(l$2tml N

W(LDihG

/

- w(LD4NG ll-0 S-

+ 6HS1 i.,

~

l M* w=,

- a/

'/

pi!!~-Fs"s.,i"*~

' ' ~

8

- Re$ 37$.a

[p#~

  • I 03-0 3<

N f

02"=0S 03-03 9

6 4

Os-08-4 If#ef R SLMFACE

  • 40 aio 0
  1. 0 40

=40

  • IO O

to 40 i

MS400AL, AMIAL STMSS,les Ml40 VAL CIRCUMf(MNflAL STMSS,666 l'

9 Figure 4.3-1 PRf*- APID POST-!HR T THROUGil-WA!.!,

l PE9fDUAL STRESS DISTR! NUT!Otl8 FOR 12" PIPS PtPr I

(Reference 12) i C EC-20-013 4*7 nutggh aaviaton i

i i

i h(25 4cm)lOm d

'I WCLO k,I M

~ ~ WCLO + 1HSI a

war,,,

OA43mi214cm) i, R4 Omt 20.3cm) yg i

  • 100 200 400 0

00 0 700 100 500.t00

  • 100 0

00 0 200 20__

i y

i e

i e

F

\\

f i

I,.

/

!l'*.

.e

.e l

l

/l

..e

/

Y

...a/

8 0

0

/

/

5, i

4

4

.e

/

d f

,/

r.

1 I

N

,\\

{

..o

.ao o

ao 40 40

.ao o

ao 40 MSNHJAL ANIAL STRESS, bei RESIOUAL CIRCUWFERCNTAL StMSS. het P

i Figure 4.3-2 i

PRE-AND POST-!HS! TilRot.fGil-WALL RE9fDt1AL STRESS DISTR!!)tJTIONS FO R 2 0 AND 22" NPS PIPES (Reference 12)

CEC-20. 013 4.8 QUkg Revision 1

L I

M Pe W Pe 50 0 tm.wm r,

kio too 300 50 0 too soo o

eon too sno ano i

u r

I y

v v

v y

OuiEn SunFACE I

\\

/

h.

l WELO I

3 1

(3S ecal 3

f

_ L )Fi40 d-l

- - WELO + IHs4 V

f

& Y no-l 8 0-I

' -~

-,,. m

~

l n

)

f

/

- n.is owas oami

/

  • t 5

$s/

~

r

/

/

/

l'

/

l I

/

h f on-

[

gon-lI

/

g

}

g I

lI

-s

-i L

w c.

g X

g

! o.

\\.

I

.so

.oo so o

to ao so

.oo

.so o

so eo nassous ma staess, i.:

useous. cincuwemweis simss.

l' 1

t i

i Figure 4.3-3 l

l PRE-AND POST-!HSI TilROUGil-WALL RESIDUAL STRESS DISTRIBUTIONS FOR 28" NPS PIPE (Rotorenco 12) 9 l

C E C-2 0-013 4'9 OUk%

Revision 1 i

I 5.0 EVALUATION METHODS AND RESULTS This section presents the evaluation methods and results used to assess the acceptability of the overlay-repaired and IHSI-mitigated weld flaws at Quad Cities Unit 2.

5.1 Flawed Pipe Analysis Table 5.1-1 presents the pipe and flaw geometric details 6

needed to calculate applied stresses and predict crack growth in the IHSI-mitigated flawed welds at Quad Cities Unit 2.

NUTECH's NUTCRAK computer program ( Refe r-es ence 13) was used to predict crack growth for the sus-tained stresses shown in Table 5.1-2.

The following conservative crack growth law was used:

~0

  • 1 I f*=3.58x10 K

(Re ference 14) p9 l'

n.

where:

II da = dif ferential crack size (inches) dt a differential time (hours)

K

= applied stress intensity f actor (k si g[in)

Table 5.1-3 presents the predicted end-of-fuel cycle flaw depths compared to the maximum acceptable flaw C E C-2 0-013 5.1 ritit. qts;.I.l.

"*" " t s

depths permitted by ASME Section XI (Re ference 4) Ta ble IWB-3641-1 and Generic Letter 84-11 ( Reference 6).

5.2 Re inforcement Weld Overlav Repair Design Table 5.2-1 presents the pipe and flaw geometric details needed to calculate the applied stress ratios shown in Table 5.2-2 and allowablo stress ratios for the l

circumferential1y flawed overlay-repaired welds at Quad Cities Unit 2.

Table 5.2-3 presents a comparison of l'g stress ratios due to applied loads versus the allowable stress ratios for the circumf erential flaws detailed in 0

Table 5.2-1.

The allowable stress ratios shown were

. calculated using the source equations of ASME Section XI Table IWB-3641-1.

These source equations are presented in Figu re 5.2-1.

g, y

Table 5.2-4 presents the pipe and flaw geometric details needad to determine applied and allowable stress ratios f or the axially flawed overlay-repaired welds at Quad Cities Unit 2.

Table 5.2-5 presents a comparison of stress ratios due to applied loads versus the allowable stress ratios for the axial flaws given in Table 5.2-4.

The allowable stress ratios shown were determined i

using the leakage barrier criteria presented in Table 3.2-1.

C EC-2 0-013 5.2 Revision 1

@{

s e

5.3 Residual St ress Improvement Weld Overlay Repair Design and Analysis Table 5.3-1 presents the pipe and flaw geometric details needed to calculate the through-wall residual stress i

distributions caused by the overlay repairs detailed in Figure 2.0-1 for Welds 0 2AS-S4 and 10S-F5.

Table 5.3-2 presents stress information for these welds.

NUTECH's l.-

WELDS II computer program (Reference 15) was used to h-determine the changes in residual stress distributions

{

I caused by the overlays.

Figures 5.3-1 and 5.3-2 present the axial stress distributions used to perform crack E

growth calculations as described in Section 5.1.

1 Table 5.3-3 presents the predicted end-of-f uel cycle flaw depths compared to the maximum acceptable depths permitted by ASME Section XI Table IWB-3641-1 (Re ference b

4) and Generic Letter 84-11 (Reference 6).

q' l

ta C E C-20-013 5.3 Revision 1 g

Ta ble 5.1-1 PIPE AND FLAW GEOMETRIC DETAILS CIRCUMFERENTIALLY FLAWED IHSI-MITIGATED WELDS Nominal ill a(2)

O.D.

t (3)

Weld ID (in.)

(in.)

(%)

t 02D-S3 12.75 0.585 28 360*

0 2M-S 4 12.75 0.585 15 360*

I 02A-S10 22.0 1.093 16 360*

028-S9 22.0 1.093 14 360*

c-02AS-S6 28.0 1.203 18 360*

3 0 2AS-S12 28.0 1.203 15 360*

0 2AS-F14 28.0 1.203 13 360*

0 2AD-F12 28.0 1.359 16 360' 0 2B S-F14 28.0 1.203 10 360*

No te s:

4 pipe wall thickness.

1.

t =

r,

/o 2.

a = beginning-of-cycle flaw depth.

3.

t = evaluation flaw length.

CEC-20-013 5.4 Revision 1 nutgg.h

Ta ble 5.1-2 APPLIED STRESSES (PSI)

CIRCUMFERENTIALLY FLAWED IHSI-MITIGATED WELDS Dead Thermal Overlay Internal Weld ID We igh t Expansion Sh rink ace Se ismi c Pressure 02D-S3 738 2005 1240 1772 6811 l'

0 2M-S4 289 134 5850 1381 6811 0

0 6290 02A-S10 J

028-S9 0

0 6290 02AS-S6 74 404 87 610 6692 0 2AS-S12 58 453 61 248 6692 0 2A S-F14 62 418 54 245 6692 0 2A D-F12 35 241 28 1028 6439 l-0 2B S-F14 90 1037 162 210 6692

  • Negligible CEC-20-013 5.5 Revision 1 nutggh

Ta ble 5.1-3 PREDICTED END-O F-CYCLE VS. ALLOWABLE FLAW DEPTHS CIRCUMFERENTIALLY FLAWED IHSI-MITIGATED FLAWS Predicted Be g inning-o f-Cyc l End-o f-Cycle Fg Allowable Elg Death Ratio Death Ratio Weld ID Flaw Depth Ratio 0 2D-S 3 0.28 0.28 0.43 0 2M-S4 0.15 0.15 0.45 0 2A-S10 0.16 0.16 0.50 0 2B-S9 0.14 0.14 0.50 0 2A S-S6 0.18 0.18 0.48 02AS-S12 0.15 0.15 0.48 U

0 2A S-F14 0.13 0.13 0.48 0 2A D-F12 0.16 0.16 0.47 1

0 2B S-F14 0.10 0.10 0.48 L

Notes:

i, 1

l.

Flaws assumed to be 360* in circumf erential length.

2.

Predicted end-of-cycle flaw depth based upon combination j'

of dead weight, internal pressure, thermal expansion, overlay shrinkage, and post-IHSI through-wall residual stresses.

3.

Allowable flaw depth based upon combination of dead weight, seismic, and internal pressure stresses divided by S From ASitC Section III (Re ference 16) App. I Tabl$. I-1.2, S, = 16,950 psi at 550*F.

CEC-20-013 5.6 Revision 1 nutggb.

Ta ble 5. 2-1 PIPE AND FLAW GEOMETRIC DETAILS CIRCUMFERENTIALLY FLAWED REINFORCEMENT OVERLAY-REPAIRED WELDS Nominal Original Repaired II)

III a(2)

,(3) g)

O.D.

t t

Weld ID (in.)

(in.)

(in.)

(%)

t 1

1 0 2 D-F6 12.75 0.585 0.976 80 0.61 8.0" 0 2F-F6 12.75 0.585 0.876 15 0.68 360*

02G-S3 12.75 0.585 0.880 32 0.67 2.25" l

0 2J-F6 12.75 0.585 0.909 15 0.65 15.0" 0 2AS-S9 28.0 1.203 1.551 23 0.36 24.0" II 02BS-S3 28.0 1.203 1.526 40 0.63 12.0" 0 2B S-F7 28.0 1.203 1.490 16 0.26 360' 0 2B D-S6 28.0 1.203 1.709 39 0.55 17.0" 10S-F1 20.0 1.016 1.345 11 0.17 6.0" 0 2E-F5 A 12.75 0.585 0.796 18 0.75 1.5" b

02t!-S3 12.75 0.585 0.840 65 0.71 3.5" 0 2M-F7 12.75 0.585 0.855 100 0.70 7.5" l

I Notes:

1.

Original t = pipe wall thickness.

Repaired t = pipe wall + overlay thickness.

flaw depth as a percentage of original pipe wall 2.

a

=

thickness.

f

= design flaw depth to overlay-repaired pipe wall 3.

thickness ratio.

4.

t

= design flaw length.

CEC-20-013 5.7 Revision 1 nutggh

Ta ble 5.2-2 APPLIED STRESSES (PSI)

  • CIRCUMFERENTIALLY FLAWED REINFORCEMENT OVERLAY-REPAIRED WELDS Dead Internal Weld ID We ich t Th e rma 1 Se ismic Pressure 0 2 D-F6 342 1303 1844 4332 02F-F6 147 2729 2202 4756 02G-S3 62 2140 1279 4737 d

02J-F6 183 339 2009 4606 0 2AS-S9 208 376 114 5319 0 2B S-S3 56 3376 167 5397 0

0 2B S-F7 233 1810 304 5513 0 2B D-S 6 16 1305 370 5305 l'

10S-F1 1132 6561 1875 4800 02E-F6A 205 1469 2475 5188 02M-S3 853 271 1415 5188 0 2!1-F7 558 4'10 2113 4882 Stresses after overlay repair.

CEC-20-013 5.8 Revision 1 nutech

Ta ble 5.2-3 i

APPLIED VS. ALLOWABLE STRESS RATIOS CIRCUMFERENTIALLY FLAWED REINFORCEMENT OVERLAY-REPAIRED WELDS Applied Allowable Stress )

Stresp2)

Ra tio( 1 Ra tio Weld ID 0 2 D-F6 0.38 1.1 02F-F6 0.42 0.5 r.

f,

-02G-S3 0.36 1.3 02J-F6 0.40 0.8 O2AS-S9 0.33 1.2 0 2B S-S3 0.33 1.1 0 2B S-F7 0.36 1.2 0 2BD-S6 0.34 1.2 10S-F1 0.46 1.4 0 2E-F6 A 0.46 1.3 02M-S3 0.44 1.3 02tt-F7 0.45 1.1 m

Note s V

1.

Applied Stress Ra tio = (De ad We ight + Se ismic + Internal From ASME Section pressure)/Sm.

III (Re ference 16) App. I Ta ble I-1.2, S,= 16,950 psi at 550'F.

2.

Allowable stress ratio is calculated using AS!!E Section l

XI (Reference 4) Table IWB-3641-1 source equations

~

(See Figure 5.2-1).

T l

CEC-20-013 5.9 4

Revision 1 l

I nut @,Qh

Ta ble 5.2-4 PIPE AND FLAW GEOMETRIC DETAILS AXIALLY FLAWED REINFORCEMENT OVERLAY-REPAIRED WELDS Nominal Original Repaired III III I2I t

1 O.D.

t We ld ID (in.)

(i n. )

(in.)

(in.)

0 2AS-S9 28.0 1.203 1.551 0.5

' ~

0 2BD-S6 28.0 1.203 1.709 1.25 02E-F6A 12.75 0.585 0.796 0.25 0 21".- S 3 12.75 0.585 0.840 0.88 Notes:

i j#

1.

Original t = pipe wall thickness.

Repaired t = pipe wall + overlay thickness e-i..

2.

t

= evaluation flaw length.

V CEC-20-013

5. 10 Revision 1 nutggh

I Ta ble 5.2-5 APPLIED VS'.

ALLOWABLE STRESS RATIOS AXIALLY FLAWED REINFORCEMENT OVERLAY-REPAIRED WELDS Applied Allowable Weld ID Ra tioIII Stresp2)

Stress Ra tio

'*/

02AS-S9 0.79 0.95 02BD-S6 0.86 0.90 02E-F6A 0.80 0.95 g.

J 02M-S3 0.80 0.90 n.

Notes:

1.

Applied stress ratio is calculated using formula presented in Table 3.2-1 footnotes.

2.

Allowable stress ratio per Table 3.2-1.

I,1 E

CEC-20-013 5.11 Revision 1 nutggh

For 2nr < 0.5 5

a gn -a7 (radians) 8

=

2 2.773 (SR) - 0.5 - f (2 sin s

  • sin a) =0 For 2sr > 0.5 l

-f)(radians) n (

j 3=

2-a 2.773 (SR) - 0.5 - f (2

  1. )

sin s = 0 Where:

1

= flaw length (inches)

'd r

-pipe racius (inches) a = halt-crack length (racians) a = flaw ceptn (inches) p.

t= pipe thickness (inches)

SR = stress ratio = Pm + Pb Pm = primary membrane 5Eress Pb = primary bending stress sm = allowable stress intensity (per ASME Section III Appendices)

{-~

t 3

'?

6.

.it a

1 -

J-

- y T

r t

Figure 5.2-1 SOURCE EQUATIONS FOR ALLOWABLE s

END-OF-EVALUATION PERIOD FLAW DEPTH-TO-THICKNESS RATIOS FOR CIRCUMFERENTIAL FLAWS s

C EC-20-013 5.12 Revision 1

@f g

3 Taile 5.3 -1 PIPE AND FLAW GEOMETRIC DETAILS CIRCUMFERENTIALLY FLAWED RESIDUAL STRESS IMPROVEMENT OVERLAY-REPAIRED WELDS Nominal Original Repaired III a(2)

III t

O.D.

t Weld ID (in.)

(in.)

(%)

(in.)

1 i

l 10S-F5 20.0 0.960 17 1.116 360*

0 2A S-S4 28.0 1.203 20 1.380 360*

Notes:

pipe wall thickness, 1.

Original t

=

Repaired t = pipe wall + overlay thickness.

f

= beginning-of-cycle flaw depth as a percentage of 4h 2.

a original pipe wall thickness.

3.

1

= evaluation flaw length.

U l\\

\\

CEC-20-013 5.13 Revision 1 nutgch

Ta ble 5.3-2 APPLIED STRESSES (PSI)

CIRCUMFERENTIALLY FLAWED RESIDUAL STRESS IMPROVEMENT OVERLAY-REPAIRED WELDS' Dead Thermal Internal Weld ID We igh t Expansion Se ismic Pressure 10S-F5-561 10,993 642 6510

.j$

i.

0 2AS-S4 156-203 242 6692 I

n b

1J A

4 CEC-20-013 5.14 Revision 1 1

nutp_q))

s

E Ta ble 5. 3 -3 i

PREDICTED END-O F-CYCLE VS. ALLOWABLE FLAW DEPTHS CIRCUMFERENTIALLY FLAWED RESIDUAL STRESS IMPROVEMENT OVERLAY-REPAIRED WELDS 1

4 Predicted Al lowable Beginning-of-Cycle End-of-Cycle Flaw III I

Deoth Ra tio I Weld ID Flaw De pth Ra tio Flaw Depth Ra tio 4

10S-F5 0.17 0.19 0.47 j

7,-

b 0 2A S-S4 0.20 0.20 0.48 I

' N

-Notes:

1.

Flaws assumed to be 360' in circumf erential length.

2.'

Predicted end-of-cycle flaw depth based upon combination of dead weight, internal pressure, thermal expansion, and modified through-wall residual stresses.

'b 3.

Allowable flaw depth based upon combination of dead weight, seismic, and internal pressure stresses divided by S From ASME Section III (Re ference 16) App. I

-im((

Tabl$.. I-1. 2, S

= 16,950 psi at 550*F.

m

'p l

l i

CEC-20-013 5.15 Revision 1 i

nutsch

~ ~ ~ _, -.

~>

1 s

t-I

)

RE510UAL AX1AL STRESS, kna

-40 4

20 0

20 40 60

. CUTER SURFACE 1

P J

0.8 i

s.

r

-- 0.8 U.

l

- 0.4

[

OISTANCE Fmou PtPE i

INNE4 $URF ACE. acres

-- 0.2 17 1<

l I$

,l' 60 4

20 0

20 40 60 J

RESIOUAL AxlAL STRESS. kne PCEC46 he2 l

l Figure 5.3-1 l

MODIFIED AXIAL RESIDUAL STRESS DISTRIBUTIONS l

FOR WELD 10S-PS s

C EC-20-013 5.16 Revision 1 g{

g

,--.._._y.,

..-__,,~r

_.r._,,

c-,m.,,,,,--_.

,,-,-w,,,,_,__..,,

RESIDUAL AXIAL STRESS, ksi

-30 20 10 0

10 20 30 t

f f

?

f f

OUTER SURFACE

-- 1.0

-- 0.8 i

j 0.6 DISTANCE FROM PIPE P

INNER SURFACE, inches

-- 0.4

-- 0.2 J

[

30 20 10 0

10 20 30 i':

RESIOUAL AXIAL STRESS, ksi FCEC85.04-01 Figure 5.3-2 MODIFIED AXIAL RESIDUAL STRESS DISTRIBUTION FOR WELD O2AS-S4 C EC-20-013 5.17

. Revision 1 QQf

~

s 6.0

SUMMARY

AND CONCLUSIONS Examinations performed during the Fall 1983 and Spring 1985 outages of the Reactor Recirculation and Shut Down Cooling systems at Commonwealth Edison's Quad Cities Nuclear Power Plant Unit 2 identified flaws judged to be IGSCC in the vicinity of twenty-four welds.

Fou rteen welds were overlay repaired, nine welds were shown to be acceptable with only IHSI mitigation, and one weld was I

removed and replaced.

4.

<j The evaluation of the twenty-three overlay-repaired and r

IHSI-mitigated weld flaws presented in this report demonstrates that the applied stress levels are accepta-ble for all design conditions.

The analysis performed in the evaluation demonstrates that the overlay-repaired b

and IHSI-mitigated weld flaws are acceptable for a minimum of one additional f uel cycle.

\\o l'

C EC-20-013 6.1 Revision 1 gg

. __... _. ~

f-l l

7.0 REFERENCES

1.

NUTECH Document No. COM-75-002, " Evaluation and Disposition of IGSCC Flaws at Quad Cities Nuclear i

Power Station Unit 2",

Revision 1, March 1984.

.1 2.

Sargent & Lundy Drawing ISI-ll3, '" Inservice Inspection Class 1 - Nuclear Boiler & Re ac tor Recirculation Piping - Quad Cities Station Unit 2",

f Revision A.

3.

Sa rgent & Lu ndy Drawing ISI-ll5, " Inservice

e.

Inspection Class 1 - RHRS Piping - Quad Cities Station Unit 2",

Revision A.

4.

ASME Boiler and Pressure Vessel Code Section XI, l*

1983 Edition with Addenda through Winter 1983.

S.

U.S.

Nuclear Regulatory Commission Document No.

[+

N UREG-10 61, " Investigation and Evaluation of I

Stress-Corrosion Cracking in Piping of Boiling Water Reactor Plants", Ma rch 1984, Draft attached to SECY-84-301, dated ' July 3 0, 1984.

i 6.

USNRC Ge neric Le tter 8 4-11, Inspections of BWR Stainless Steel Piping", April 19, 1984.

l i

l C E C-20-013 7.1 Revision'l g

L l

1 7.

NUTECH Document No. N SP-81-10 5, "De s ig n Re port for Recirculation Safe End and Elbow Repairs -

Monticello Nuclear Generating Plant", Re vision 2, December 198 2.

8.

NUTECH Docwnent No. COM-76-001, " Weld Overlay Design Criteria for Axial Cracks", Revision 0, March 1984.

9.

NUTECH Document No. COM-57-003, "St ress Co rrosion Cracking Evaluation Program for Quad Cities Station Unit 2",

Revision 0, March 1983.

P 10.

EDS Reactor Recirculation System Analysis (NRC IE Bulletin 79-14), NUTECH File No s. C EC0 20.0 010.0 006 and CE C0 2 0.0010.000 7.

1 11.

NUTECH Computer Program PISTAR, Ve rsion 3.1, User's Manual, Volume 1, T R-7 6-00 2, Revision 1, NUTECH File No. 08.003.0300.

12.

EPRI Documen t No. NP-2662-LD, " Computational Residual St ress Analysis f or Induction Heating of Welded BWR Pipes", December 198 2.

13.

NUTECH Computer Program NUTCRAK, Re vision 2.0.2, December 198 3, NUTECH File 0 8.0 3 9.000 5.

C EC-20-013 7.2 rititgts;t!

14.

NUTECH Communication Record, P.

K.

Nagata (NUTECH) and W.

S.

Hazelton (USNRC), June 22, 1984.

15.

NUTECH Computer Program WELDS II, Ve rs ion 1.0.0, July 198 3, NUTECH File 0 8.05 3.000 2.

16.

ASME Boiler and Pressure Vessel Code Section III, 1983 Edition with Addenda through Winter 198 3.

J n

L e

l' C E C-20-013 ggg[s()

ne:r V i S io n 1 amaan

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