ML20205C697

Forwards Addl Info Re SER Open Item 15 Concerning Arbitrary Intermediate Pipe Breaks.Viewgraphs of Presentation from 860604 Meeting W/Nrc & Results of Weak Link Analysis for Welded Attachments Encl

ML20205C697
Person / Time
Site:	Vogtle
Issue date:	08/04/1986
From:	Bailey J GEORGIA POWER CO.
To:	Youngblood B Office of Nuclear Reactor Regulation
References
GN-1022, NUDOCS 8608120445
Download: ML20205C697 (37)

Text

4

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Georgia Power Company Post Offica Box 282 Waynesboro, Georgi 2 30830 Telephone 404 554 9961 404 724 8114 Southern Company Services, Inc.

Post Office Box 2625 Birmingham, Alabama 35202 reiennone 205 8me "

Vogtle Project August 4, 1986 Director of Nuclear Reactor Regulation File: X7BC35 Attention: Mr. B. J. Youngblood Log: GN-1022 PWR Project Directorate #4 Division of PWR Licensing A U. S. Nuclear Regulatory Commission Washington, D.C. 20555 REF: LETTER FROM NRC, DATED JULY 2, 1986, TO GEORGIA POWER COMPANY ON AB0VE SUBJECT NRC DOCKET NUMBERS 50-424 AND 50-425 CONSTRUCTION PERMIT NUMBERS CPPR-108 AND CPPR-109 V0GTLE ELECTRIC GENERATING PIANT - UNITS 1 AND 2 SER OPEN ITEM 15: ARBITRARY INTERMEDIATE PIPE BREAKS

Dear Mr. Denton:

Attached is the additional information requested by the NRC related to the arbitrary intermediate pipe breaks (AIPB) issues on VEGP (see referenced letter).

The information provided is as follows:

Attachment 1 - Summary of presentation made by GPC during the meeting held with NRC Staff on June 4, 1986. j l

Attachment 2 - Results of weak link analysis for welded attachments within 5 pipe diameters (SD) of AIPB location on main steam and main feedwater systems for VEGP Unit 1. .

l Attachment 3 - Proposed future criteria for evaluating the effects of welded attachments within SD of AIPB locations for high energy ASME Class 2 & 3 and B31.1 piping systems.

Attachment 4 - Responses to NRC Staff questions (see referenced-letter). l I

Attachment 5 - Method of analysis / treatment of welded attachments on VEGP design. This is provided to outline how ASME Code requirements are met at VEGP for welded attachments.

\

8608120445 860804 4 DO 3 DR ADOCK 0500

Director of Nuclear Reactor Regulation File: X7BC35 August 4, 1986 Log: GN-1022 Page 2 The enclosed information reflects the current status as of this date. The final reconcilation is expected by December of this year. GPC respectfully requests an expeditious review of the information provided.

Should you have any additional questions, please inquire.

Sincerely,

.[.

J. A. Bailey Project Licensing Manager JAB /sm Attachments xc: R. E. Conway R. A. Thomas J. E. Joiner, Esquire B. W. Churchill, Esquire M. A. Miller (2) l B. Jones, Esquire G. Bockhold, Jr.

NRC Regional Administrator NRC Resident Inspector D. C. Teper W. C. Ramsey L. T. Gucwa Vogtle Project File 0634V I

l 1

i l

Attachment 1 i

SUMMARY

OF PRESENTATION TO NRC STAFF ON JUNE 4, 1986 <

i l

A meeting was held on June 4, 1986.between NRC staff and Georgia I Power Company (GPC) to discuss Vogtle Electric Generating Plant (VEGP) arbitrary intermediate pipe break (AIPB) issue. The pur-pose of the meeting was to present the current technical and as-

built information with respect to welded attachments within 5 pipe diameters (5D) of a postulated AIPB. The material presented updated the information submitted by GPC to NRC in letter dated May 9, 1986 (Log GN-902) and provided the additional information delineated in the same letter.

The material presented consists of the following:

i

a. Typical types of welded attachments used at VEGP (see j enclosure to this attachment).

1

b. Discussion of the number of welded attachments within 5D of I current high stress points. The NRC was informed that during

, May 1986, an additional review was performed using as-built 1 information and field walkdown measurements. This resulted j in fourteen (14) welded attachments within 5D of a current I high stress point. Four (4) of these attachments were voided and one (1) from stress standpoint was enveloped by an adjacent welded attachment. Consequently, detailed stress I information was provided for nine (9) welded attachments.

These nine cases are provided in the enclosure to this attachment. Since the NRC meeting, a tenth case has been added. This case was discussed in the May 6, 1986 letter and concerns break location 1064C which was eliminated due to the fact that the high stress point was located at the middle of the elbow and is outside the SD guideline. However, since break locations must be considered at both elbow-to-pipe l connections, the break location (not the high stress point) moves within SD of the welded attachment. Based on this, it is included as Case 10 in the enclosure to this attachment.

! c. Discussion of stress dissipation along the pipe axis-and GPC's proposed alternate criteria for evaluating effects of

welded attachments within close proximity to AIPB locations.

The view graphs used during the meeting are provided as enclosure to this attachment. More detailed discussion is provided in Attachment 3.

4 d.

Discussion of the further information requested by NRC. This is documented by NRC letter dated July"2, 1986 by Melanie A.

Miller (see Reference 1) l I 1/1

l s

I. OPENING REMARKS .

o DEFINITION OF WELDED ATTACHMENTS o HISTORICAL

SUMMARY

II. DISCUSSION OF WELDED ATTACHMENTS WITH]N 5D OF CURRENT HIGH STRESS POINTS o DESCRIPTION OF WELDED ATTACHMENTS WITHIN 5D o LOCAL STRESS DISSIPATION ALONG PIPING AXIS o W/A LOCAL STRESS CONTRIBUTION AT CURRENT HIGH STRESS LOCATION l

III . FUTURE PROJECT CRITERI A i

o LOCAL STRESS VS HIGH ENERGY PIPE BREAK POSTULATION

TYPICA_ WELDED ATTACHMENTS

1. LUGS

2. PIPE STANCHION (DUMMY STUB)

3. PIPE STANCHION WITH l REINFORCING PAD

4. ANCHOR STRAP .

5. BEARING PAD  :

i

TYP::CA_ WELDED ATTACHMEh S -

i '

1.. LUGS LUG STEEL

\ I li

_______________4 il I PIPE ,_,_,_,_,_,_,_,_ . . . _

g_______________

I

2. PIPE STANCHION (DUMMY STUB)

I I I I SNUBBER

/

f l lT] l.Il 1

-.1:.

wlmaal l i I i l l1 l

i I *Il I , l

_ _ _ _ _ . ,1,l. ______9 l

_a . . PIPE ,_,___,4,___,_,

• l L_______J_______

l I i

1 - .

l

- _ _ _ _ . . ___l

. 1

3. PIPE STANCHION WITH REINFORCING PAD ,

h

'i' per- + \ SNUBBER i.I ljl t l .l l l lI

_ W_ _ ____g 1

l

_{ r . q_P I. P_E. ._._._._3_._._._.

. _______J_______

l l

4. ANCHOR STRAP

___. ____3 p P LPE_ . , _ _ . . , _ . _ _ . . _ , _ ,. _ . .

I V

[ __

l i

5. BEARING PAD

__ _ _ _ _ _ _ ___ _ _ _ _ _ _ g

_ .IN _ . ._._. . _. _. ._.

1 i r_____ _____

STEEL # STEEL ' '

ARBITRARY INTERMEDIATE BREAKS ~

HISTORICAL

SUMMARY

o GN-281 NOVEMBER 11, 1983 GPC TO NRC INITIAL REQUEST FOR ELIMINATION OF ARBITRARY INTERMEDIATE BREAKS IDENTIFIED 182 BREAK LOCATIONS AND 110 PIPE WHIP RESTRAINTS TO BE ELIMINATED o GN-352 APRIL 26, 1984 GPC TO NRC ..

STATED THAT WELDED ATTACHMENTS WERE NOT LOCATED WITHIN FIVE PIPE DIAMETERS OF ORIGINAL SET OF BREAKS TO BE ELIMINATED o NRC LETTER JUNE 28, 1984 NRC TO GPC SAFETY EVALUATION REPORT ON ARBITRARY BREAKS ,

(NRC APPROVAL)

REQUIRED WELDED ATTACHMENTS TO BE ADDRESSED AS STATED IN ASME CODE NC/ND 3645 DID NOT ADDRESS 5D AS A CRITERION i

[

.- J l

WELDED ATTACHMENT LOCATIONS e A REVIEW WAS MADE IN MARCH 1984 182 BREAK LOCATIONS REVIEWED NO WELDED ATTACHMENTS IDENTIFIED WITHIN 5 PIPE DIAMETERS RESULTS OF REVIEW TRANSMITTED TO NRC (4/84) GN-352 o REVIEW PERFORMED IN JULY 1984 PRIOR TO FSAR SUBMITTAL WELDED ATTACHMENTS WERE IDENTIFIED WITHIN 5 DIAMETERS OF 6 BREAK LOCATIONS DISPOSITION OF THE -

WELDED ATTACHMENTS WAS MADE IN ACCORDANCE WITH THE NRC JUNE 28, 1984 LETTER ft

^ '

..- . . .. . . . ,L -.

~^

.. : . : . . . . zi. ;.. .. . . .. . .;.; . -

6 l

l 9 .

I II. DISCUSSION OF WELDED -

ATTACHNENTS WITHIN 5J OF CURRENT HIGH I

STRESS POINTS I

I 4

i l

i WELDED ATTACHMENTS WITHIN 5J OF CURRENT HIGH ,

STRESS POINT 6 LUGS 3 DUMMY STUBS -

1 BEARING PAD 4 VOIDED DUMMY STUBS 14 TOTAL DISPOSITION WAS MADE IN ACCORDANCE WITH THE NRC JUNE 28, 1984 LETTER i

+ - . - - - - - , _ _ _ - _ . _ . , . . . _ , . _ _ _ . , . . . . _ . . . _ _ _ _ . . . . , . _ , , _ _ _ _ . _ . , _ , _ _ . . . , , . . , . . _ , , . _ _ . . , , , ,

e,

. LOCAL STRESS DISSIPATION  !

1 ALONG PIPING AXIS

! ' ' ^ ~ ~ ' '

I Mx X '

= = .

p .

\ U /

R \

k/

/ \

/ A

)\ \

UNIFORM RADIAL PRESSURE OF P LB. PER LINEAR ]N. OF CIRCUMFERENCE OF SECTION REMOTE FROM ENDS P

MAX M = 4 A AT POINT OF LOAD APPLICAION Mx=(Max M)[e-AX (CosAx-SinAX)] WHERE A= 4 3(12)2 rg 2 2 N

Ak 100 -

r

$ 80 ' -s L w -

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E 60 - -~4, ,

3  : ri i l

I 40 - -

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y  : _- \

et ;24 rt ;34rt ;44 et )

z 20 s e i i

u.  : _ \ I# A ! 2/A p/A 5/Aj j O g N I .! l  ! i %

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. I. .!,- l x __ i i - -- - -

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-20 N---~ NORMALIZED SHAPE OF i

. DISCONTINUlTY MOMENT l l

JUSTIFICATION FOR LOCAL STRESS DISSIPATION i

o CODE CASES N-318-2 AND N-392 STATE THAT:

'FOR MULTIPLE ATTACHMENTS LOCATED AT A l DISTANCE LESS THAN l'FT FROM EACH OTHER, 1

THE STRESS EFFECTS FOR EACH INDIVIDUAL ATTACHMENT SHALL BE SUPERIMPOSED.'

o WRC BULLETIN 198 PAGE 6 STATES THAT, ACCORDING TO BIJLAARD, THE MAXIMJM STRESS DUE TO THRUST OR MOMENT LOADING OCCURS AT THE BOUNDARY OF THE ATTACHMENT.

O FORMULAS FOR STRESS AND STRAIN BY R.J.

ROARK, FOURTH EDITION, PAGE 301, TABLE

.XIII, CASE 11.

i di 's *.. .

JA

= - MAXIMUM LOCAL STRESS LOCAL STRESS 25% OF MAXIMUM (pst) LOCAL STRESS A B C DISTANCE FROM EDGE OF W/A

=

N Pt  ; ALONG PIPE AXIS

'3 N e t I

^

A B C HIGH STRESS LOCATION

1

. l I.

COMPARISON OF V rt WITH SD l CASE "55YTIE t r V rt 3Vrt SD IN. IN. IN. IN. IN. IN.

1 3 .216 1.642 .596 1.79 15 2 8 .322 4.152 1.15 6 3.47 40 l 3 3 .437 1.532 .818 2.45 15 4 3 .437 1.532 .818 2.45 15 5 26 1.022 12.489 3.57 10.72 130 i 6 38 1.4 31 18.285 5.12 15.35 190 7 6 .562 3.03 1.31 3.92 30 8 4 .337 2.082 .838 2.52 20 1 9 2 .343 1.016 .590 1.77 10 i

DE' ALLS OF WELDED ATTAC-NENTS AT BRE AK LOCAT\ONS NOTE: THE WELDED ATTACHMENT REVIEW FOR ITEN 5 THE FIFTH PAGE FOLLOWING, HAS BEEN REVISED TO REFLECT A CORRECTED EQUATION 9 + 10 COMBINED STRESS AT DATA POINT 148. THE PREVIOUS VALUE OF STRESS LISTED (10,487 PSI) DID NOT INCLUDE THE CONTRIBUTION DUE TO PRESSURE OF 7,537 PSI. THE COMBINED STRESS THEREFORE INCREASES TO 18,024 PSI. THIS DOES NOT AFFECT THE MAGNITUDE OF THE MAEIMUM INTERACTION STRESS OF 33,541 PSI.

l 1

6155t

_- _ _ _ _ - ._ ._. _ _ __.._.)

, WELDEJ ATTACHMENT REVIEW SYSTEM..................... CHEMICAL & VOLUME CONTROL STRESS CALCULATION........ 7001A ISOMETRIC................. 1K3-1208-066-01 CURRENT HIGH STRESS POINT (CHSP)....... 26A PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1208-066-H006 PIPE SUPPORT DATA POINT... 26A LEVEL A LOCATION................... AUX BLDG STRESS DATA EQUATION 9+10 LOCAL STRESS q 10+ LOCAL STRESS

' " " 0" e DP 26A e DP 26A W.R.C. CODE CASE (CHSP) (W/A) W.R.C. CODE CASE METHOD METHOD METHOD METHOD 8.363 8.363 4.910 6 620 13.273= 14.993=

. 8( 1. 2 Sh + So ) - 32,752 PIPE BREAK THRESHOLD 34rt - 1. 79'

.- 1 6 3/4" X 1/2" X 2' LUG (HXWXL>

(TYP)

[ 26A l

3 E( 19 ), 9' - )

, O.

g, O

2' DIA

)

l PREVIOUS HIGHEST , ,

STRESS LOCATION g (RELOCATED DUE N3 DIA TO FCR)

= THE STRESS VALUES PREVIOUSLY SUBMITTED VERE CONSERVATIVELY CALCULATED.

- l l

THE STRESS VALUES SHOWN REFLECT THE ACTUAL APPLICABLE LOAD COMBINATIONS.

WELDEJ ATTACHMENT REVIEW 2

SYSTEM.....................vASTE EVAPORATOR STEAM STRESS CALCULATION........ 7083A ISOMETRIC................. 1K3-1314-084-03 CURRENT HIGH STRESS POINT ( CHSP ) . . . . . . . 800 PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1314-084-H013 PIPE SUPPORT DATA POINT... 160 LOCATION................... AUX BLOG LEVEL A STRESS DATA EOUATION 9+10 LOCAL STRESS 9+10+ LOCAL STRESS

) N ON S BESS c OP 900 0 DP 160 V. R. C. CODE CASE W.R.C. CODE CASE (CHSP) (W/A) METHOD METHOD METHOD METHOD 21,974 4.187 1,500 1,734 21,974 21,974 32,400 PIPE BREAK THRESHOLD . 8( 1. 2 Sh + So ) -

34rt -3. 47 '

160 800 l' X l' X 3' ~

LUG (HXWXL) \ 7 (TYP) ,,

. /

PREVIOUS HIGHEST 8' DIA ,

STRESS LOCATION (RELOCATED DUE TO FCR) j a

= PER WALKDOWN .

WE_JEJ ATTACHMENT REVIEW 3 SYSTEM..................... CHEMICAL & VOLUME CONTROL STRESS CALCULATION........ 7092 ISDMETRIC................. 1K4-1208-005-02 CURRENT HIGH STRESS PDI NT ( CHSP ) . . . . . . . 88 PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1208-005-H006 PIPE SUPPORT DATA POINT... 90 LOCATION...................CONTMT BLOG LEVEL B STRESS DATA EQUATION 9+10 LOCAL STRESS 9+10 fO LOCAL TRESS c DP 88 e DP 90 W.R.C. CODE CASE (CHSP) (w/A) W.R.C. CODE CASE METHOD METHOD METHOD METHOD 23 301 8.806 2.420 4.840 23,301 23.301

. 8( 1. 2 Sh + Sc ) - 32,126 PIPE BREAK THRESHOLD 34rt 2.45" 90 RED- N 3" X 2" kss .

2' DIA 3" DIA 88 g

<a 'e . 1 3/4' X 1/2' X 2" LUG (HXWXL)

(TYP)

= INACCESSIBLE DUE TO INSULATION. l DIMENSION FROM AS-BUILT USED E

WEL.DED ATTACHMENT REVIEW 7

SYSTEM..................... CHEMICAL & VOLUME CONTROL '

STRESS CALCULATION........ 7092 ISOMETRIC................. 1K4-1208'-005-02 CURRENT HIGH STRESS POINT ( CHSP ) . . . . . . . 156 PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 50 OF CHSP..........V1-1208-255-H001 PIPE SUPPORT DATA POINT... 155 LOCATION...................CONTMT BLOG LEVEL B STRESS DATA

^

EOUATION 9+10 LOCAL STRESS 9+10+ LOCAL STRESS e DP 155 ( WA) MM INTERACTION STRESS e DP 15B C DP 155 W.R.C. CODE CASE (CHSP) (W/A) W.R.C. CODE CASE METHOD METHOD METHOD METHOD 24,297 8,997 2,420 4,840 24,297 24,297 32,126 PIPE BREAK THRESHOLD . 8( 1. 2 Sh + Sa ) -

34r t -2. 45' 3' X 2' RED 155

~

2' DIA 3' DIA f

O  % 1 4'e

• 3/4' X 1/2" X 2'

= INACCESSIBLE DUE TO INSULATION ESTIMATED DIMENSION FROM FIELD (h

WALKDOWN IS SLIGHTLY LARGER DIMENSION FROM AS-BUILT USED e

R e v o s t o n .L WE's DED ATTACHMENT REVIEW 5 SvS1ss.....................sAIn STEAn STRESS CALCULATION........ 7073/74 ISOMETRIC................. 1K5-1301-001-01 CURRENT HIGH STRESS POINT (CHSP)....... 68 l

PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1301-008-H052 PIPE SUPPORT DATA POINT... 148 LOCATION................... AUX BLDG LEVEL 1 STRESS DATA EQUATION 9+10 LOCAL STRESS 9+10+ LOCAL STRESS 14 ) N ON SmESS e DP 68 o DP 148 W.R.C. CODE CASE (CHSP) W/A> V.R.C. CODE CASE METHOD METHOD METHOD METHOD A

33 541 [ / 8,02 'f ) 12,410 13,691 33,541 33,541

.8(1.2 Sh*Sa) - 37,800 PIPE BREAK THRESHOLD 34rt 10. 72' 148 12" DIA SCH 80 DUMMY STUB \g

/

68 1 1/4" THK 38' X 26' RED

~

REINFORCING PAD 33 SAME AS PREVIOUS INACCESSIBLE DUE TO INSULATION PER FIELD HIGHEST STRESS VALKDOWN. DIMENSION FROM AS-BUILT USED. LOATION a

1 l

l 1

WELDED ATTACHMENT REVIEW l 6 S STEM..................... MAIN STEAM STRESS CALCULATION........ 7073/74 ISOMETRIC................. 1K5-1301-001-01 CURRENT HIGH STRESS PDINT (CHSP)....... 15_

PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 50 OF CHSP..........V1-1301-008-H055 PIPE SUPPORT DATA POINT... 147 ,

LOCATION................... AUX BLOG LEVEL 1 STRESS DATA O

EOUATION 9+10 LOCAL STRESS q.1g.gOCAL STRESS DP 147 (W/A) MAX INTERACTION STRESS e DP 75 c DP 147 V. R. C. CODE CASE W.R.C. CODE CASE (CHSP) (W/A) METHOD METHOD NETHOD NETHOD 24,646 14,326 8,850 8,368 24,646 24,646

.8(1.2 Sh+So) - 37,800 PIPE BREAK THRESHOLD 26' DIA 75 O j I 147 i

",'d ,1 hQ 147A ENVELOPED 38' X 26' RED '

, s

= -18' DIA SCH 80 N DUMMY STUB (TYP) 38' DIA PIPE BREAK P-1055C .

SAME AS PREVIOUS INACCESSIBLE DUE TO INSULATION PER FIELD HIGHEST STRESS l WALKDOWN. DIMENSI,0N FROM AS-BUILT USED. LOCATION l i

WELDED ATTACHMENT REVIEW 7 SvSTes.....................sa1s PeeOwATes STRESS CALCULATION........ 7072C ISDMETRIC................. 1K3-1305-154-01 CURRENT HIGH STRESS POINT (CHSP)....... 11A PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1302-107-H001 PIPE SUPPORT DATA POINT... 11A LOCATION................... AUX BLDG LEVEL A STRESS DATA EQUATION 9+10 BEARING STRESS 9+10+ LOCAL STRESS c DP 11A o DP 11A c DP 11A (W/A) MAX INTERACTION STRESS C

23,434 23 434 3.550 26,984

. 8 ( 1. 2 Sh + Sa ) - 32,400 PIPE BREAK THRESHOLD 3J r t - 3. 92

/

/

11A t /

1/2' THK REINFORCING

/' PAD

• <ri nr m ^ T T A ni ikA r NIT DC \/ " chi W L L. LJ t. U HI I H L i il*l L. I N I I u_ v . 1._ ev SYSTEM..................... MAIN STEAM STRESS CALCULATION........ 7075 ISOMETRIC................. 1K5-1301-012-01 CURRENT HIGH STRESS POINT (CHSP)....... 255 PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 50 OF CHSP..........V1-1301-012-H026 PIPE SUPPORT DATA POINT... 252 LOCATION................... TUNNEL IT68 LEVEL A STRESS DATA EQUATION 9+10 LOCAL STRESS q.10+ LOCAL STRESS -

e DP 255 o DP 252 V.R.C. CODE CASE W.R.C. CODE CASE (CHSP) (W/A) ,

METHOD METHOD METHOD METHOD l

15.917 680 837 27,716 27.716 27.716

. 8( 1. 2 Sh + Sc ) - 32,400 PIPE BREAK THRESHOLD 34rt 2. 52' i ,

2 2, 1

'O.

t b

.' 3/4" X 1/2' X 2 t/2' A' LUG ( HXWXL )

(TYP)

A 4' DIA

= INACCESSIBLE FOR FIELD VALKDOWN ,

WORST CASE CONSTRUCTION TOLERANCE ASSUMED. l t

m WELDEJ ATTACHMENT REVIEW --_

q SYSTEM..................... CHEMICAL & VOLUME CONTROL -

STRESS CALCULATION........ 7003A ISOMETRIC................. 1K7-1208-044-01 CURRENT HIGH STRESS POINT ( CHSP ) . . . . . . . 19 PIPE SUPPORT WITH WELDED ATTACHMENT (W/A)

WITHIN 5D OF CHSP..........V1-1208-044-H015 PIPE SUPPORT DATA POINT... 17A LOCATION...................FUjl HDLG BLDG LEVEL A STRESS DATA EOUATION 9+10 LOCAL STRESS 9+10+ LOCAL STRESS e A /A) .A N A N Ess c DP 19 c DP 17A W.R.C. CODE CASE (CHSP) (W/A) W.R.C. CODE CASE METHOD METHOD METHOD METHOD 18,783 7,219 4.070 8.877 18,783 18,783

. 8( 1. 2 Sh + So ) - 33,680 PIPE BREAK THRESHOLD ,

34rt - 1. 77 '

1 1/2' DI A 18 v.^

I 1/2' X l' SWG / 3/4' X 1/2' X 1 1/4' LUG (HXWXL) 2' X l' SWG (TYP) 2' DIA i I

1 l

l 17A l

= PER FIELD WALKDOWN l l

1

i . ,r i ,r, ar,an i , e r , , ,- , r- , , ,- . .

WELJtJ HI I H L Nivit lN I 1t V 1.W 1.0 S Y S T E M_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . MA I N S T E AM STRESS CALCULATION _____________ 7073/74 I SOMETR I C _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1 K5 - 1301 -0 02 -01 CURRENT HIGH STRESS PO INT ( CHSP)____________ 545 PIPE SUPPORT WITH WELDED ATTACHMENT ( W/ A)

W I TH I N 50 0F CHSP_ _ _ _ _ _ _ _ _ _ _ _ _ _. V 1-1301-007-H001 PIPE SUPPORT DATA POINT ______ 551 LO C A T I ON _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. C O N T. BLOG. LEVEL A STRESS DATA EQUATION 9+10 LOCAL STRESS 9+10+ LOCAL STRESS

@ DP ( W/ A ) MAX INTERACTION STRESS Q DP 545 0 DP 551 W. R. C. CODE CASE W. R. C. CODE CASE

( CHSP) ( W/ A ) METHOD METHOD METHOD METHOD 20172 14499  ; 13340 15905 27839 30404 DIPE BREAK THRESHOLO . 8( 1. 2 SH+SA) =37800 l

54 P-1064-C 6 3,

22 N ,gc-  %,.9.*'

6 A

,g ,

551 j1'sG

1. 'e - O f

- a /

t .

'" e v } 1a.

o, s

%y srugc,e D0 u

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• a 4

Attachment _2 RESULTS OF WEAK LINK ANALYSIS 4

Objective / Basis For. pipe supports with welded attachments (W/A) within 5D of arbitrary-intermediate break locations (AIBL) on Main Steam and Feedwater piping, determine where the weak link occurs in the pipe-to-support-to-structure load path. The weak link is defined as the critical section, either in the pipe wall or on a support member or weld connections, where the least design margin exists.

4 i

Scope Six supports that have W/A within SD of AIBL on Main Steam and I Feedwater piping have been evaluated. They are:

V1-1301-008-H052 [Horz. Axial Snubber Attached to a Dummy Stub /

Pipe Sleeve on Main Steam in the Auxiliary Bldg.] See Attachment 1, dwg. no. 5.

V1-1301-008-H055 [ Vertical Rigid Support Attached to a Dummy  !

, Stub on Main Steam in the Auxiliary Bldg.]

See Attachment 1, dwg. no. 6, data point no. 147.

V1-1301-008-H056 [Horz. Lateral Snubber Attached to a Dummy Stub on Main Steam in the Auxiliary Bldg.] See Attachment 1, dwg. no. 6, data point 147a.

I V1-1301-012-H026 [ Variable Spring Hanger With Riser Clamp and Lugs on Main Steam in the Outside Area] See ,

Attachment 1, dwg. no. 8.

V1-1302-107-HC01 [360 Sleeve Bearing on Structural Steel.m Auxiliary Feedwater Piping in the Auxiliary l Bldg.] See Attachment 1, dwg. no. 7.

V1-1301-007-H001 [ Vertical Rigid Restraint with Dummy Stub on Main Steam Piping in the Control Bldg.-]

See Attachment 1, dwg. no. 10.

Method of Analysis The following method was followed to determine the weak link:

1. The ratio of the actual versus allowable faulted condition

) primary local stress was calculated in the pipe wall at the

{ welded attachment.

4 1/3 i

a. Primary' general pipe stresses were obtained in accordance with NC-3652 Equation 9 for faulted conditions. (General pipe stresses due to thermal expansion, seismic anchor movement and building settlement are self-limiting secondary stresses which are not included in the faulted condition evaluation per NC-3652 Equation 9.)

b. Primary local pipe stresses were calculated based upon i the total pipe support faulted load (which includes Thermal, Seismic Anchor Movement and Building ,

Settlement). The local membrane stress in the pipe near  !

the welded attachment due to the external load was con-4 sidered primary local membrane stress (PL) in accordance i with.ASME Section III, Division 1, Appendix XIII, Table XIII-1130-1.

l

c. The primary general pipe stresses were added to the

primary local stresses to obtain the total primary f j stress.

) d. The allowable stress for faulted condition (3.0 Sh'*)

I' was obtained in accordance with Figure XIII-1141-1 of Appendix XIII with k=2 -for faulted condition per

. Table Nc-3217-1.*

e. The results of Item c (calculated stress) and Item d

! (allowable stress) were used to determine the design 4 margin available, which is' defined as the percentage of l allowable stress remaining for use.- It is calculated as j follows:

! Design Margin = 1- Actual Stress X 100%

Allowable stress

2. For pipe support standard components such as snubbers and pipe clamps, the calculated faulted-conditicn load was i divided into the vendor's allowable faulted condition load to

{ obtain a design margin similar to that described above, i

i .

{ 'This table was added to ASME Section III in the Winter '76 l Addenda. It replaced Table NC-3218-1. Table NC-3217-1 defines l k values for design, normal, upset, emergency, faulted, and

test conditions. Comparing Appendix XIII between the addenda i applicable to the Vogtle Project (Summer '75) and the Winter i

'76 addenda, paragraphs XIII-1122 and XIII-1153 are revised.

These revisions do not impact the method used for evaluation of

. local stresses at welded attachments.

• • Sh is used instead of Sm conservatively. ,

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3 For pipe support miscellaneous steel, welds, bolts, embed plates, etc., the ratios of the faulted condition allowable load to the faulted condition load were calculated. (AISC is the governing code for miscellaneous steel.)

4. The results of Items 1 through 3 above at all critical members and sections were compared, and the item with the least design margin was identified as the weak link.

Results Design Margin Pipe Support Weak Number Pipewall Support Link

1. V1-1301-008-H052 57.2% 10.7% Snubber

2. V1-1301-008-H055 67.9% 30.4% Weld 6 i Beam / Embed 3 V1-1301-008-H056 70.5% 30.4% Weld 6 Beam / Embed

4. V1-1301-012-H026 83.3% 14.0% Spring

5. V1-1302-107-H001 65.6% 58.0% Weld 6 Tube '

Steel / Plate

6. V1-1301-007-H001 78.5% 64.7% Wide Flange (W8-88)

Note: These results were calculated and documented in Vogtle calculation No. X4CP-S-0110 Conclusion In all six cases the critical section of the pipe support structure / component is the weak link and the combined local and general piping stresses at the welded attachment are below the threshold of 0.8 (1.2 Sh + Sa). Therefore, pipe breaks will not be postulated.

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-. .. .-. =

Attachment'3 I. Proposed Future Criteria for Evaluating the Effects

! of Welded Attachments Within 5 Piping Diameters of i Arbitrary Intermediate Break Locations (AIBL) for High i Energy ASME Class 2 & 3 and B31.1 Piping Systems

1. For ASME Class 2 and 3 and'B31.1 high energy piping intermediate breaks (excluding AIBL) where applicable,.

i shall be postulated in accordance with the criteria of  ;

l MEB 3-1 where the combined equation 9 and 10 stresses l exceed the threshold of 0.8 of the combined equation 9 i and 10 allowables.

2. If less than the minimum intermediate breaks have been

] postulated, then the W/A in the vicinity of the highest i stress location (in the event that one intermediate j j break is postulated), or the two highest stress loca-

] tions (in the event that no intermediate breaks are i postulated) will be reviewed to determine if breaks need l to be postulated. Breaks need not be postulated at these high stress locations if one of the following 3 conditions is met:

]

, a. NoW/Aiswithin3/Rt of the highest stress j location (s):

R= The mean pipe radius based on 1/2 nominal pipe diameter and thickness.

I t= The pipe nominal thickness.

j b. If the combined stress ssipated local (Fig. 1) l plus general) within 3 Rt of the high stress location does not exce the threshold of 0.8 of the combined equation 9 and 10 allowables.

I Note: Equations 9 and 10, whose combined results are compared against a threshold value of 0.8 times the combined equation 9 and 10 allowable, to postu-late break locations, do not consider the effect of local stresses due to welded attachments. In i Appendix XIII of the ASME B&PV code,Section III,

) when the effects of welded attachments are consid-

! ered an increase in the allowable stress is per-mitted. For example, the equation 9 allowable for general piping stress is 1.2 Sh whereas the allow-

able stress per Appendix XIII, when considering the j local primary effects of welded attachments, is 1 1.65 Sm for upset conditions. It can therefore be-

concluded that use of the threshold value of 0.8 i

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times the combined Equation 9 and 10 nilownbles to postulate pipe breaks when local effects of welded l attachments are considered is conservative,

c. The pipe wall at the W/A-to-pipe interface is not the weak link in the W/A-support-structure analysis (using the method described in' Attachment 2).

II. Method of Implementation of the-Proposed Criteria

1. As-built pipe support and piping isometric drawings shall be used to determine the distance between the edge

of the welded attachment and the edge of the break j location.

i

2. Design Criteria DC-1017'and DC-1018~shall be revised ,

along with the FSAR to describe the criteria for l addressing welded attachments in the vicinity of inter- l

mediate high stress locations.below the pipe break threshold. ,

J l i 3 The criteria shall be' implemented each time a piping l

stress calculation-is revised due to a cignificant l change in pipe size, wall thickness, routing or loading conditions.

l

4. Documentation of. break locations will continue to be j reflected in the FSAR.

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f j

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. . . I l

\

h

= MAXIMUM LOCAL STRESS LOCAL STRESS 25% OF MAXIMUM (pst) LOCAL STRESS A B C DISTANCE FROM EDGE OF W/A

=

N "t = ALONG PIPE AXIS 3N et _

,sa s f f HIGH STRESS LOCATION fl G u R E .$ -

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Attachment 4 RESPONSE TO NRC-STAFF QUESTIONS i RELATED TO MAY 9, 1986 LETTER (see Reference 1)

Question 1: Identify the 6 systems in which the welded attach-ments are located. Are any of these systems subject to thermal cycling?

a. Case 1, V1-1208-066-H006 Chemical & Volume Control System, Letdown line from Heat Exchanger to Mixed Bed Demineralizer.

i 1 b. Case 2, V1-1314-084-H013

- Waste Evaporator Steam Supply System, from the electric steam boiler to the boric acid batching tank and waste / recycle

evaporator,

c. Case 3 & 4, V1-1208-005-H006 & VI-1208-255-H001 Chemical & Volume Control System, both are on lines from the Regenerative Heat Exchanger to the Containment penetration.

d. Case 5 & 6, V1-1301-008-H052 and H055

i. Both of these are on the Main Steam Line.

All of the above are subject to thermal cycling to various degrees. However, conservative case thermal transients for any systems have been considered in Calculation X4 CPS-0094 and fatigue limits have been met. 'Specifically, a review of system thermal transients was made and the letdown and auxiliary feed-water systems were determined to have the most severe temperature transients. The auxiliary feedwater piping experiences a total

, of 2810 cycles for all temperature transients. The various tran-i sients considered temperatures ranging between 32 F to 445 F.

The letdown piping experiences a total of 2300 cycles for all temperature transients. The temperagures considered for these j

transients vary between 70 F and 570 F. l The conservative case transients considered were used to evaluate the piping at one welded attachment location on each of the two piping systems. The analysis was similar to that used for per- )

forming Nuclear Class 1 stress analysis for Class 1 piping with welded attachments. NB-3600 and Code Case N-122 were used.

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L The results show that for lugs and dummy stubs (stanchions)

F located in these systems that undergo the most severe temperature transients, resulting stresses meet the allowable fatigue limit.

The cumulative usage factor considering the effects of the dummy

. stub on the auxiliary feedwater line is 0.76. The cumulative.

usage factor considering the effects of the lug on the letdown line is 0.68. The remaining Class 2 and 3 systems, where transients are less severe, are expected to be enveloped by the cases studied.

,uestion Q 2: Identify the ASME Code _ Case which was used to calculate the " Code Case Method" stress.

l For shear lugs, Code Case N-318-2 (approved by Reg. Guide 1.84) was used to evaluate the stresses. For dummy stubs (trunions)

Code Case N-392 (approved by Reg. Guide 1.84) was used, i

Question 3: Describe the type of attachments in question.

a. Case 1, V1-1208-066-H006 has 2 shear lugs (3/4" x 1/2" x j 1/2") (H x W x L).

b. Case 2, V1-1314-084-H013 has 2 shear lugs (1" x 1" x 3").

c. Case 3, V1-1208-005-H006 has 2 shear lugs-(3/4" x 1/2" x 2").

i d. Case 4, V1-1208-255-H001 has 2 shear lugs (3/4" x 1/2" x 2").

e. Case 5, V1-1301-008-H052 uses a 12" sch. 80 dummy stub which

.; is welded to a 1 1/4" reinforcement sleeve which in turn is j welded to the piping.

i j f. Case 6, V1-1301-008-H055 uses an 18" sch. 80 dummy stub.

q Question 4: Do dummy stubs have potential to carry load? If so, j is the support welded directly to the pipe or is there a saddle welded between the support and the pipe.

Dummy stubs do carry loads (capable of transferring loads from pipe to structure). Of the two cases mentioned above: 1) H052, the dummy stub is welded to a 1 1/4" reinforcement sleeve around

the pipe. 2) H055, the dummy stub is welded directly to the pipe.

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Attachment 5 l

i METHOD OF ANALYSIS / TREATMENT OF 4

WELDED ATTACHMENTS AT VEGP i

Local stresses at welded attachments were evaluated to ensure that stresses remain within code limits as follows: i NC-3645 of the ASME code provides a general statement for l

guidance, but no specific design rules for. addressing local

, stresses. When the code does not provide explicit design rules, NC-3200 allows the use of detailed analysis in accordance'with

, Appendix XIII. This appendix defines the equations used to

{ combine general and local stresses and their associated  ;

i allowables.

j Lugs and Dummy Stubs j The project has utilized the method of Appendix XIII to combine ^

l the effects of local stresses at lugs and dummy stubs with the general pipe stress to ensure that local stress effects have been j considered in the evaluation of piping stresses.

J l For lugs and dummy stubs the criteria has been implemented by two

! means - standard design and non-standard design.

Standard designs for lugs and welded attachments have been -  ;

developed utilizing the detailed analysis method presented in l

! Welding Research Council Bulletin 107 (WRC-107). Local stresses for these standards are limited to 10,600 psi based on assumed values of general pipe stress in straight pipe. Backup calcula- l 4

tions for these standard designs are on file, i

j For non-standard lugs and dummy stub designs local stresses were i calculated using the method of WRC-107 and combined with the

] general piping stresses to satisfy the allowables of l Appendix XIII.

Bearing Plates 1

! Standard bearing plate sizes for various pipe sizes and wall 1 thicknesses were developed using " Formulas for Stress and Strain" i by Raymond J. Roark, 4th edition, 1965 (Table XIII, Case 9). The l allowable local stress = 18,900 psi based on assumed values of l general pipe stress in straight pipe.

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NC-3685 also states that the design of welded attachments should take into consideration thermal gradients. However, since NC-3645 gives no explicit method of performing this analysis the method described in NB-3600 and Code Case N-122 were recently

! used to evaluate welded attachments on those systems that exper-ienced worst case transients. See Attachment 4 for a more detailed discussion of this analysis, i

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