ML20034C659

From kanterella
Jump to navigation Jump to search
Summary of 900419 Meeting W/Util Re Cracks & Other Indications Found on Unit Reactor Vessel Head.List of Attendees & Licensee Slides Encl
ML20034C659
Person / Time
Site: Quad Cities Constellation icon.png
Issue date: 04/27/1990
From: Olshan L
Office of Nuclear Reactor Regulation
To:
Office of Nuclear Reactor Regulation
References
NUDOCS 9005040293
Download: ML20034C659 (96)
v • d • e


Text

{{#Wiki_filter:. April 27,1990 Docket No. 50-265 DISTRIBUTLON:. G uptasures NRC & Local PDRs FMiraglia PDI11-2 r/f Licensee: Commonwealth Edison Company RDudley L01shan LLuther OGC-WF1 Facility: Quad Cities Station, Unit 2 EJordan ACRS(10) JClifford JPartlow

SUBJECT:

MEETING

SUMMARY

- APRIL 19, 1990 MEETING TO DISCUSS QUAD CITIES UNIT 2 REACTOR VESSEL HEAD CRACKS On April 19, 1990, the NRC staff met with Commonwealth Edison (the licensee) to discuss the cracks and other indications found on the reactor vessel head for Quad Cities, Unit 2.

A list of the attendees is provided in Enclosure 1. The slides presented by the licensee are included in Enclosure 2. The licensee presented a detailed discussion of the examinations performed (visual dye penetrant and ultrasonic), the initial results of the metallurgical testsofseveralboatsamples,andthefabricationhistoryofthevesselhead. General Electric (GE), the nuclear steam supply system vendor, presented industry experience with clad cracking. The licensee excavated a sufficient number of cracks to determine the crack depth and to confirm the results of the ultrasonic testings. The most limiting crack depth resulting from the excavations and boat samples was used by the licensee in the ASME Code Section XI fracture mechanics analysis. The analysis concluded that an assumed crack of 0.7" would not grow more than.050" during the next fuel cycle, and that the required margin of the ASME Code is satisfied for operation with existing flaws. l During the presentation, the NRC staff raised concerns about other back-clad r areas in the vessel, in particular the beltline region, and in other similar BWRs throughout the country. To address this concern, the licensee had GE perform a fracture mechanics evaluation of a postulated flew in the beltline region. This analysis indicates that high fracture margins exist and indications i fourd thus far pose no fracture concern even if postulated to be in the beltline region. GE stated that it will inform its customers of the Quad Cities Unit 2 i experience and recommend future inspections and other followup actions. The licensee presented its planned future activities to support the restart of Quad Cities Unit 2 on May 2, 1990. The licensee indicated that they will complete the metallurgical analyses of all Quad Cities Unit 2 boat samples, review fabrication records of their other BWR vessels to identify target regions for inspection and establish an examination action plan for upcoming refueling outages for their other BWR vessels. The staff intends to review these examination plans after the licensee has completed the metallurgical i / f3 9005040293 900427 y ADOCK0500gggD DR

. analysis and their review of f abrication records. The NRC staff raised no objection to the licensee's fracture mechanics analysis and restart plans as presented at the meeting. /s/ Leonard N. Olshan, Project Manager Project Directorate 111-2 Division of Reactor Projects 111 IV, Y and Special Projects Office of Nuclear Reactor Regulation

Enclosures:

As stated cc: See next page ? l l l DOCUMENT NAME: MEETING W/QC

  • SEE PREVIOUS C0'CURRENCE Office:

LA IAN PM/PDill-2 NRR/ MTB-(A) 111-2 3 Surname: thec L01shan/tg

  • CYC RDudley Date:

/A/90 4/te/90 04/ 0 4./11/90 (i(26(9 0

I gpa tseg'o,, UNITED STATES I { eq g NUCLEAR REGULATORY COMMISSION e a WASHING TON. D. C. 20665 g, l k.....,/' April 27, 1990 Docket No. 50-265 i Licensee: Commonwealth Edison Company Facility: Quad Cities Station, Unit 2

SUBJECT:

MEETING

SUMMARY

- APRIL 19, 1990 MEETING TO DISCUSS QUAD CITIES UNIT 2 REACTOR YESSEL HEAD CRACKS On April 19, 1990, the NRC staff met with Connonwealth Edison (the licensee) to discuss the cracks and other indications found on the reactor vessel head for Quad Cities, Unit 2.

A list of the attendees is provided in Enclosure 1. The slides presented by the licensee are included in Enclosure 2. The licensee presented a detailed discussion of the examinations performed (visual, dye penetrant and ultrasonic), the initial results of the metallurgical tests of several boat samples, and the fabrication history of the vessel head. General Electric (GE), the nuclear steam supply system vendor, presented industry experience with clad cracking. The licensee excavated a sufficient number of cracks to determine the crack depth and to confirm the results of the ultrasonic testings. The most limiting crack depth resulting from the excavations and boat samples was used by the licensee in the ASME Code Section XI fractere mechanics analysis. The analysis concluded that an assumed crack of 0.7" would not grow more than.050" during the next fuel cycle, and that the required margin of the ASME Code is satisfied for operation with existing flaws. During the presentation, the NRC staff raised concerns about other back-clad areas in the vessel, in particular the beltline region,_and in other similar BWRs throughout the country. To address this concern, the licensee had GE l perform a fracture mechanics evaluation of a postulated flaw in the beltline l region. This analysis indicates that high fracture margins exist and indications found thus far pose no fracture concern even if postulated to be in the beltline region. GE stated that it will inform its customers of the Quad Cities Unit 2 experience and recommend future inspections and other followup actions. The licensee presented its planned future activities to support the restart of Quad Cities Unit 2 on May 2, 1990. The licensee indicated that they will complete the metallurgical analyses of all Quad Cities Unit 2 boat samples, i l review fabrication records of their other BWR vessels to identify target regions for inspection and establish an examination action plan for upcoming l refueling outages for their other BWR vessels. The staff intends to review these examination plans after the licensee has completed the metallurgical

2 analysis and their review of fabrication records. The NRC staff raised no objection to the licensee's fracture mechanics analysis and restart plans as presented at the neeting, l'04 Leonard N. 01shan, Project Manager Project Directorate III-2 Division of Reactor Projects III IV, Y and Special Projects Office of Nuclear Reactor Regulation

Enclosures:

As stated cc: See next page i t i 1 l l 1 l

o j Pr. Thorr.as J. Kovach Quad Cities Nuclear Power Station Commonwtalth Edison Company Units 1 and 2 CC: Mr. Stephen E. Shelton Vice President Iowa-Illinois Gas and Electric Company P. O. Box 4350 Davenport, Iowa $2808 Michael 1. Miller, Esq. Sidley and Austin One First National Plaza Chicago, Illinois 60690 Mr. Richard Bax Station Manager Quad Cities Nuclear Power Station 22710 206th Avenue North Cordova, Illinois 61242 Resident inspector V. S. Nuclear Regulatory Commission 22712 206th Avenue North Cordova, Illinois 61242 Chairman Rock Island County Board of Supervisors 1504 3rd Avenue Rock Island County Office Bldg. Rock Island, Illinois 61201 1111nois Department of Nuclear Safety Office of Nuclear Facility Safety 1035 Outer Park Drive Springfield, Illinois 62704 Regional Administrator, Region !!! U. S. Nuclear Regulatory Commission 799 Roosevelt Road, Bldg. #4 Glen Ellyn, Illinois 60137 4 l L

ENCLOSURE 1 LIST OF ATTENDEES APRIL 19, 1990 MEETING ON QUAD CITIES 2 REACTOR VESSEL HEAD CRACKS }l fi CECO } C. Y. Cheng R. Bax H. Conrad D. Gibson D. Danielson S. M. Gaitonde R. Dudley R. Rybak B. Elliot T. Spry T. Greene R. Stols R. Herman R. Tamminga A. Hiser R. Tuetken B. Hayes G. Wagner V. Hodge B. Wilson M. Hum E. Igne GE W. Koo 57 Delwiche S. Lee E. Kiss G. Millman J. Leatherman J. Muscara W. Miller L. 01shan S. Ranganath P. Randall J. Richardson OTHER C. D. Sellers E! Connor, NRR Calendar J. F. Smith H. Edwards Consultant to CECO J. Wechselberger R. Jones, EPRI K. Wichman W. Koch, Moline Dispatch / Rock J. Zwolinski Island Argus E. White Associated Press t 1 J

ENCLOSURE 2 COMMONWEALTH EDISON NUCLEAR REGULATORY COMMISSION TFCHNICAI MFFTING 1 QUAD CITIES STATION i UNIT 2 1 REACTOR VESSEL HEAD J APRll 19,1990 --_-_-_____-_.._.-..--.-n--,-----,,,,--.----,,-s----n..-.,-+-ve-,rn-,m--~--,re,~~e-mov~.-we,w - ~-nw ew ww -em---w~~---we w~ t ew wvxwor*,-*

e m. /... : ..,. m m. x ~ L AGENDA \\ ' y m t i.:. s u w w + w iu kz u.i w + m I INTRODUCTION R.TUETKEN i EXAMINATIONS R. TAMMING A i METALLURGICAL TESTING RESU LTS R. GAITONDE FABRICATION R. TAMMINGA i INDUSTRY EXPERIENCE E. KISS (GE) WITH CLAD CRACKING 1 FRACTURE MECHANICS S.RANGANATH i ANALYSIS (GE) A ROOT CAUSE AND R.TUETKEN ACCEPTABILITY OF CONTINUED OPERATION FUTURE INSPECTION R.TUETKEN PLANS CONCLUDING REMARKS R.TUETKEN NRC QUESTIONS & COMMENTS s -m - mm _,-,m______, -.-ww 3,.-- egr,.

l l l sm1cmnw12m PURPOSE Fn masqutetusta::.sthu,va*C,7 i l l TO DISCUSS THE FOLLOWING ACTIVITIES t ASSOCIATED WITH QUAD CITIES UNIT 2 REACTOH VESSEL HEAD CRACKS: i i + EXAMINATIONS PERFORMED l METALLURGICAL-TESTING RESULTS l 4 i + FABRICATION HISTORY + INDUSTRY EXPERIENCE + FRACTURE MECHA~NICS ANALYSIS I + ROOT CAUSE/ ACCEPTABILITY OF CONTINUED OPERATION L + FUTURE INSPECTION PLANS J 4 d s.+--.,., .m---m .---,--,.-,.-...--,.--w,-,.---,- ..~...,..--,--.-r ..m__.,-,--..-.+.--.--m-.-w-.

l' .n. ,a REACTOR VESSEL HEAD .nummme. BACKGROUND + COMMONWEALTH EDISON PERSONNEL I NOTED DISCOLORATION ON CLADDING + LlQUID PENETRANT AND ULTRASONIC EXAMINATIONS PERFORMED BY CONTRACTOR + INDICATIONS WERE BELIEVED TO BE 2 LIMITED TO CLADDING + GRINDING OPERATION. REVEALED THAT CRACK WENT BEYOND l CLADDING + INVESTIGATIVE TEAM FORMED INCLUDING ENGINEERING, PROJECT MANAGEMENT, AND MATERIALS ANALYSIS DEPARTMENTS + EXTENSIVE EXAMINATIONS AND ENGINEERING REVIEWS CONDUCTED

1 '- 78 _ mf

-ss, g g"*

EANANAND Y ri j. a$ i I \\. '~ k p .M. I Og I .k r i 1.% l P t" I 4g. l !D $ sss. RR l E f 5 5 mE i i n N p g i l: !i:f 3 3 4 I .h\\\\\\%Y a q 'w me g. 3 P. i s

QUAD CmES UNIT S RPV HEAD POSSIBL3 agggggATCH l l Head Closure Torus Ctad - 37" i i Back Clad 33%" = ) Mismatch 5/8" Max l -Weld Build-Up j. 25" = Flange -Flange Clad n t j 584 Transparency Mounting Frame Commercial Tape Division 3 e C 'n***.0

2 g;g -44 +

St. Paul, MN'55144 v33 i .m..,... ,y,e.---.r-,, ,.,,r,-..,.,v---..,--,, ,.,..,--._.,%.m_ ___,.,..,,,_,,m._.,

2 A

8...

a. 2 L 4. A s. t i i t i i _ o, r__

  • 7N

-~ga i g. i ~. w---e i. .n w i lt l Y= t' i % y, !i V 'i i j 1 1 l tj I %h 9 i i e 1 e j i n 4 i l f l 5 ~ M* ,4 g l ;= + '} Q: N i' O'"B s m -- -- -/3 : t i 3 g i l g g w 5 1, i l t I ,i 1 i e I I

{

i t i-t g 1 l i i e I t 4 i a i k f. 1 g l h I i f* l i i i 21 8, (r 3 sa $f HW HY T _.,, + w

1 1 '.sM'[I I REACTOR VESSEL HEAD l

-umannuinHWJimmEmlaetw FINDINGS 4

i l

  • ULTRASONIC EXAMINATION PROVIDED GOOD IDENTIFICATION AND DEPTH i

ESTIMATION FOR INDICATIONS + LARGEST INDICATION INTO BASE MATERIAL WAS LESS THAN 0.250" i f 3 l + STRESS CORROSION CRACKING INITIATED IN THE CLADDING AND PENETRATING INTO THE BASE METAL + FABRICATION RELATED DEFECTS I IN HEAT AFFECTED ZONE OF BASE MATERIAL l l I 4 ..,..-.,,_n-...-,--._....._,..,._,,..

,s$ -eg. ^ * - REACTOR PRESSURE VESSEL HEAD 3-

c. ccmmmc.

l AREAS tiXAMINED ( i VISUAL + COMPLETE VISUAL EXAMINATION OF INTERIOR SURFACE OF VESSEL HEAD i I PT EXAMINATIONS i + 100% OF BAND 34" TO 39" ABOVE I FLANGE FACE + 30% OF DOLLAR WELD CLADDING CIRCUMFERENCE I + 100% OF HEAD CENTER NOZZLE CLADDING j UT EXAMINATIONS l

  • 100% OF BAND 34" TO 39" ABOVE FLANGE l

FACE + 180' OF DOLLAR WELD CIRCUMFERENCE 4 OTHER AREAS + 100% OF VESSEL FLANGE TO SHELL L CLADDING BY CAMERA q . -- J

x . 3. ; _p.,,,,ig.;.p.:. ; NDE EXAMINATION OF VESSEL HEAD nu ;;. :, : :. : ^ '

a

. t n. . n e m m r W T L.

  • GENERAL OBSERVATIONS
  • SURFACE INDICATIONS WERE FOUND PRINCIPALLY IN 0 TO 90 REGION

+ INDICATIONS WERE PREDOMINANTLY CIRCUMPERENTIAL

  • INDICATIONS WERE GENERALLY IN A BAND 3 PEET ABOVE FLANGE PACE

+ EVIDENCE OF HEAVY GRINDING FROM 25"-37" ABOVE FLANGE FACE l

6". NDE EXAMINATION OF VESSEL HEAD

r::m3nenmynnwrrwx-:en wc-l PT RESULTS

+ EXTENSIVE INDICATIONS IN BAND 36 TO 38 INCHES IN 0 TO 90 REGION l + HEAVY BLEEDOUT IN SOME CASES l I j + LONGEST INDICATION 30 INCHES l l

  • SEVERAL SHORT INDICATIONS IN l

90' TO 360' REGION I i j I 5 l I i b l 1 l

e e ..,,. 1 7 NDE EXAMINATION OF VESSEL HEAD .m::c. a-i m ; m. c o n s n a r_ %.vwe 4, 1 (CONTINUED) l

SUMMARY

1 I PERCENT OF CIRCUMFERENCE ~ 11 % + l WITH PT INDICATIONS l j REPORTED NUMBER OF ~34 + LOCATIONS ? RPV HEAD ID 790" CIRCUMFERENTIAL LENGTH P i l l l 4 l l I I i

-a ULTRASONICS l m.* .. _~amwsriestFrawsh l OUTSIDE SURPACE (100%) I + 45' AND 80' SHEARWAVE,1 MHZ + CALIBRATED ON HOLES AND NOTCHES IN THE VESSEL BLOCK AND l CRD NOZZLE MOCK UP i + PLANAR INDICATIONS l + DEPTHS ESTIMATED BY AMPLITUDE AND SWEEP OF SIGNALS DEEPEST INDICATIONS SIMILAR TO 0.314" DEEP s NOTCH IN CRD NOZZLE MOCKUP DEEPEST INDICATIONS ABOUT 0.1" INTO BASE e METAL l l + CLAD THICKNESS VARIES FROM ABOUT l 0.25 TO 0.5 INCHES AT 36 TO 38 INCHES ABOVE FLANGE FACE I + IN 90' TO 360' REGION,15 INDICATIONS FOUND WITH NO CORRESPONDING PT [ INDICATIONS E - _ _ _ _. _ _ _ _. _,. _,. ~ _. _ _ _ . _ _... -. -... _ _.,......., _. _.,., _.. ~.... _

i ) b l 2:?.. ULTRASONICS 3: A- .. m m r m r e s a re: 3 v (CONTINUED) l lNSIDE SURFACE (ON SELECTED AREAS). j l EPRI SIZING TECHNIQUE + i MORE ACCURATE DEPTH SIZING l + l DEEPEST FLAWS ESTIMATED AT 0.2" + i INTO BASE METAL j

SUMMARY

+ PERCENT OF CIRCUMFERENCE ~32% WITH UT INDICATIONS j REPORTED NUMBER OF ~22 + LOCATIONS RPV HEAD 0D CIRCUMFERENTIAL 814" ) + LENGTH i 7 i;

s. -e; EXPLORATORY GRINDING 'a t - t T itr v m it e r ". m i l lNCREMENTAL GRINDING WITH PT EXAMINATIONS l l l l 1 l

  1. 3 AND 22. DEEPEST BASED ON UT l

i TRANSVERSE INDICATION (#3) + ONLY TRANSVERSE INDICATION AND j HEAVY PT BLEEDOUT l l

  • CRACKING THROUGH CLADDING INTO i

BASE METAL (ACID ETCH) + MAXIMUM DEPTH OF EXCAVATION TO REMOVE FLAW 0.38" (INCLUDING t CLAD) i e + BASE METAL PENETRATION 0.10"

i i l an.;tx: EXPLORATORY GRINDING sij m.ach m ?%de.=3~.w w*na m W (CONTINUED) i _CIRCUMFERENTIAL INDICATION (#22) 3 l l + HEAVY BLEEDOUT AND DEEPEST BY UT l

  • CRACKING THROUGH CLADDING INTO l

BASE METAL (ACID ETCH) i + MAXIMUM DEPTH OF EXCAVATION TO REMOVE FLAW 0.58" (INCLUDING CLAD) f i + BASE METAL PENETRATION 0.15" SEVEN ADD _LTADNAL AREAS GROUND IN l CLADDING i i I + GRINDING FROM 1/16" TO 3/16" DEPTH i l + INDICATIONS NOT REMOVED, INDICATED LENGTH SHORTENED i j + UT SHOWED NO PENETRATION OF BASE METAL

1-l --e BOAT SAMPLES l , x-w;mwammuumsrs-l NO.1 FROM INDICATION #18 i l + SAMPLE CHOSEN FOR HEAVY PT i j BLEED OUT AND STRONG UT i AMPLITUDE AND SWEEP i

  • SAMPLE ABOUT 0.4" DEEP

+ CAVITY GRINDING ESTABLISHED i MAXIMUM CRACK DEPTH OF 0.55" i (INCLUDING CLAD)

  • BASE METAL PENETRATION 0.18" i

NO. 2 FROM INDICATION #24 + SAMPLE CHOSEN FOR NO PT INDICATIONS BUT HIGH UT AMPLITUDE AND SWEEP (SUBSURFACE INDICATION) - + ESTIMATED UP TO 0.2" INTO 3 BASE METAL BY UT + CRACK INDICATION IN-CAVITY l + CAVITY GRINDING ESTABLISHED MAXIMUM CRACK DEPTH OF 0.55" l (INCLUDING CLAD) 4 i + BASE METAL PENETRATION 0.225" i

1 i ~ BOAT SAMPLES V.n - dis 1NE m WL!*sA s : (CONTINUED) NO. 3 FROM INDICATION #23 1 i j + SAMPLE CHOSEN FOR NOT BEING j IN SAME PLANE AS OTHERS j (25" ELEVATION) i l + " SPIDER WEB" PT INDICATIONS IN CLAD l + CAVITY DEPTH ABOUT 7/8" J i + NO PT INDICATIONS DEEP IN CAVITY i NO. 4 FROM 60" ABOVE FLANGE FACE + SAMPLE CHOSEN FOR BEING FROM A TYPICAL HEAD CLAD AREA (SUB ARC) AND A REGION OF HIGH STRESS j + NO VISUAL OR UT INDICATIONS I _.. _,.. _ _.

r i ,4 1 n* - mumammmmanea.:.m BOAT SAMPLES 2 Wesgata,9.seacci. t (G.QRIIRy.ED1 /1 t 1 I NO. 5 ADJACENT TO H_O. 2 A7 GREATER DEPTH I ) I' i + SAMPLE CHOSEN TO CAPTURE CRACK MISSED IN NO. 2 e { e' i g4 8 t + NO PT INDICATION IN C,AVI,TY AFTER 1,. i i REMOVAL M 3s gi ,')ytc U / 6 ri e is e : i + SAMPLE ABOUT 0.7" DEEP sI J'I 4,\\, ' > \\ .o ( t, i f I . ;, f, ,/ d: e, s l ..o 9 .p. / 4 'g N ' / 3 s, s \\ .,.~ l[ -] s, y 4 g c I s / \\ \\ s '] ,, (, (> i r s 3 s s, .i 't, s.t,y k j ~bs q - 4 (/ )' h~ L -s ),/, l g,? 7 ]i. L,,,,...- --.i....i

h'y. v. l M. CONCLUSIONS 4 r:,. ...switnm. mwn:. o .i-s ,) \\ l ./ '^ l j, DEEPEST FLAW DEPTHS WERE ESTABLISHED i .,\\ .f i i MAXIMUM DEPTH INTO BASE METAL ~ ESTABLIS'HED AT 0.225" t P 4 UT SIZING RESULTS VERIFIED BY GRINDOUTS ? / i ,o r \\ I,' l l I >l I 9 j f I r, \\, i 4 y s a s ) 4 s V .\\

I- -. 7h + I.b .,y. e ~ d 'e. =am 9 f,,,,; - 3 t- -1 a e, 1 s. t I / t I ti l i r '. if~ l c' i l l I) . E+, 1 'x.' , t. 4 : sy\\ O i, s y i P 1 . I'i 'g _ . eg i ) j r' i3 h I.. !, W i o t e 1 i g 1 l p I- ,f

e c, n p
  • f, l 4.

l e. \\ .'s "t. C J r i i f, I' l 4 f 4k,8 ,,l, 't \\ mQ I ~ ~ /----- -*l I 1 ,_g,. / v-g g + I / e iT. - i 7 o' l' 'h O I sp-r i; i 1 ll = l

! w j

I i h 4 I t f 6 ,o s. . c. l l C = !l l =- 8 4 i g-q U N p l M g-- i n Ae ssss. t 1 w i 0-W- i j i N I['[ ' N l o i a 4 8 q j . sl. 83 .1l i r asmxxm, 5 = ~ 4., g u

FlQugs 2 / -e 7 / [ ./ /. / / / l 3 g"- ,/ MM45 .op o-INDICATIONS // 35 /11n =2 "i / / ww"- , [ g/ J ~ n'%: -d s o % "' "3i i T P-e //,

p, a/

,e > Mu W /./ =! /'/ / s /;/ ~ l p l l // l / '/; \\ / / ~ 1 (A c m cROSG GECTioM Visw/ OF RE. ACTOR. WE AD TC flu.!QE WELO l GKeTcw PRopocED FRon B 4# B4W: OWG _ o

n j GUAD CITIES UNIT 2 RPV HEAD 1 POSSIBLE 80lSARATCH 3 Head Closure i Torus Clad - 37" Back Clad 1 33%" = Mismatch-5/8" Max L Weld Build-Up r 25" Flange Flange: Clad i i i Scotcfj i Pd'"i?.?"fy M unting Frame COmmerClal Tape Division -5 St. Paul, MN.551'44 .e

2 ,.. ~c.

4., :..

METALLURGICAL TESTING RESULTS WMt; f . ; :;i r : ; &sw:t&%gfsnraSW. 2WaMM";. 2a GENERAL i + 5 BOAT' SAMPLES HAVE BEEN REMOVED FROM THE REACTOR-VESSEL HEAD 3 BOAT SAMPLES REMOVED TO OBTAIN A a REPRESENTATIVE SAMPLE OF INDICATIONS 1 BOAT SAMPLE REMOVED FROM OUTSIDE OF = THE AREA OF CRACK INDICATION. AN ADDITIONAL BOAT SAMPLE OF SUBSURFACE CRACK INDICATION-WAS REMOVED TO INVESTIGATE SUBSURFACE. i DEFECTS + METALLURGICAL TESTING EXAMINATION RESULTS METALLOGRAPHY = MICRO HARDNESS I =

,g. 3 3:;. MET LLURGICAL TESTING A

RESULTS,

... ~ i m a n h w - E.+ 1 m ' i n a BOAT SAMPLE #1 LOCATION i + -81/2" SURFACE FLAW BETWEEN 93"-101 1/2" OF VESSEL-CIRCUMFERENCE

  • SAMPLE CENTERED AT 95.5"

+ INDICATION #18 BOAT SAMPLE SIZE + LENGTH: 2.05" + WIDTH: 0.63" l + DEPTH: 0.38" + CLAD THICKNESS: 0.25"

  • BASE METAL:

0.08" RESULTS + SINGLE INTER-DENDRITIC CRACK IN OUTER CLAD LAYER + EXTENSIVE INTER-DENDRITIC BRANCHING IN THE INNER LAYER + CRACK IN THE HAZ HEAVILY OXIDIZED + INTERGRANULAR ALONG PRIOR AUSTENITIC GRAIN BOUNDARIES i I

m p

- ^,, _ _ - _ -[

[_3,,,.'.

Q,.

1 METALLURGICAL TESTING l RESULTS-W/ A u.;> n ~.- :1.7 1c.; U t m ? m s plL3!n M 1" 0 BOAT SAMPLE #3 LOCATION + 6" SUR5 ACE FLAW LOCATED 25" ABOVE FLANGE BETWEEN 160" 166" OF VESSEL CIRCUMFERENCE 4 + INDICATION #23 BOAT SAMPLE SIZE i + LENGTH: 2.85"

  • WIDTH:

1.30" + DEPTH: 0.80" + CLAD THICKNESS: 0.40-0.45"_ (AP PR OX.) + BASE METAL: 0.25-0.30" l RESULTS + INTER-DENDRITIC STRESS CORROSION CRACK IN CLAD

  • -CRACK TERMINATED AT THE FUSION LINE J-

+ POSSIBLE INCIPIENT PIT FORMATION AND CORROSION AT CLAD CRACK TIP i

s ^ ' ' ' .~ ' ^ '.. '.. .,., ' N ,3 METALLURGICAL TESTING RESULTS ,: p u. rc ..7 p.yy,pm m a,gpq2gp BOAT SAMPLE #2 l LOCATION + SUBSURFACE FLAW BASED ON UT EXAMINATION AT 177" AND 193" OF VESSEL CIRCUMFERENCE (IN 90AND 180' QU ADRANT) + INDICATION #24 BOAT SAMPLE SIZE l + LENGTH: 2.1 "

  • WIDTH:

0.70" + DEPTH: 0.45" + CLAD THICKNESS: 0.30" + BASE METAL: 0.10" RESULTS + SUBSURFACE CRACK NOT CAPTURED + EVIDENCE OF INCIPIENT INTER-DENDRITIC ATTACK CRACK INITIATION FROM HEAVILY COLD WORKED + SURFACE LAYER (DUE TO GRINDING) i

,.,.:.w g ; w...._ METALLURGICAL TESTING RESULTS ~ I -.~ n -?':f V ~ '& m ' " Mf%i' - BOAT SAMPLE-#4 LOCATION + SAMPLE TAKEN AT 60" ABOVE FLANGE + SUB ARC CLAD BOAT SAMPLE SIZE + LENGTH: 2.35" + WIDTH: 0.85" + DEPTH: 0.55"

  • CLAD THICKNESS:

0.28" + BASE METAL: 0.27" RESULTS + NO INTERGRANULAR PENETRATION OR INCIPIENT CORROSION CRACKS + NO FUSION LINE DEFECTS + NORMAL BAINITE HAZ STRUCTURE

l. L .V 1 F;'^^.. ~ . ; ^ " ;; ' '.;;;; M.;.:.ir :s.;;~, f EM,b,.#

SUMMARY

OF MICRO-HARDNESS DATA

f
3.ti~

s J m i 3 "i:-: g g q!;;; g & q gl y g re 3 L g ; ; M.,_ SAMPLES 1 THRU 4 I CLAD METAL YER RC/RB SAW: '207-212 RB 92 ! SMAW 223 258 AVE RC 20 g 1 SAW & SMAW 288-301 RC 28-30 l BASE METAL 200 RB91 DEPTH OF HAZ SAMPLE # DEPTH COMMENT 1 1.7 M M + END'OFSAMPLE 2 2.1 M M + END OF SAMPLE' 3 1.92 MM SMAW PROCESS i 4 4.0 M M + END OF SAMPLE -4 i l ~ -. -

~c n.WM a - BOAT SAMPLE EXAMINATIONS .. * 'M&%%kGsi&sM1iL: M=.hd3%bi?6M ' SAMPLE #1 + INTER DENDRITIC STRESS CORROSION CRACKS OBSERVED TO. PENETRATE INTO HAZ s + CORROSION AT THE INTERFACE (CLAD CRACK TIPS) + CRACK IN HAZ HEAVILY. OXIDIZED'AND FOLLOWED PRIOR AUSTENITIC GRAIN BOUNDARIES SAMPLE #2 + SUB SURFACE DEFECT NOT CAPTURED. + EVIDENCE OF INCIPIENT INTER-DENDRITIC-ATTACK INITIATED AT HEAVY COLD-WORK (GRINDING) SAMPLE #3 + INTER-DENDRITIC STRESS CORROSION CRACK IN CLAD + CRACKTERMINATED AT THE FUSION LINE + POSSIBLE INCIPIENT PIT FORMATION AND' CORROSION AT CLAD CRACK TIP-SAMPLE #4 + -NO INTER-DENDRITIC STRESS CORROSION [ CRACKS IN CLAD 4 + NO FUSION LINE DEFECTS 4 e .-...____...-....._,4 .,_..m. -...,,-,-#-y..,.....,.-_wo..ve,wnr,,m.,.w.w,,,y,_, ,,-y.

q

SUMMARY

OF BOAT SAMPLE EXAMINATIONS L a-. -~-g - p w swa L L OTHER OBSERVATIOPLS. l -+ NORMAL MICROSTRUCTURE IN HAZ + HAZ HARDNESS (RC 28-30) i + DEPTH OF HAZ 'SAW > 0.2 INCH = SM AW - 0.1 INCH J = CONCLUSION + SURFACE CLAD CRACKS-INTER-DENDRITIC STRESS = CORROSION CRACKING i KNOWN CONTRIBUTING. FACTORS = 4 HIGH STRESS (WELD RESIDUAL) HIGH CARBON CONTENT g LOW FERRITE q + HAZ CRACKS HEAVILY OXIDlZED - STRESS CORROSION = L ALONG PRIOR AUSTENITIC GRAIN BOUNDARIES .I LONG INCUBATION TIME = SLOW GROWTH EXPECTED FROM = LABORATORY DATA l + SUBSURFACE CRACK IN SAMPLE.#5-PRESENCE OF CRACK CONFIRMED DEPTH OF CRACK (0.2") IN HAZ CONFIRMED INVESTIGATION CONTINUING =

\\ a = FA.BRICATION HISTORY

^-

. s.;;.;. p .,_9 ; , m; gg + CLOSURE HEAD DESIGN + FLANGED DOME WITH 0-RING SEALS IN SHELLMATING SURFACE + THICKNESSES.- BASE METAL ORDERED PLATE - 4.25" MIN MINIMUM FINISHED - 4.00" BASIS FOR STRESS REPORT = ACTUAL IS > 4.00 a

  • ASME CODE REQUIRED 3.0751"-MIN 3

+ THICKNESS - CLAD 3/16" NOMINAL = 1/8" MINIMUM = M 5 .a i I l l

..a i FABRICATION 1 HISTORY 1

1. :

,=... ~ : :

:.. m a a n n = --

} (CONTINUED) l L FABRICATION SEQUENCE + -3 MAJOR COMPONENTS L TOP DOLLAR PLATE = \\ TOROIDAL SECTION ASSEMBLED [ FROM 6 FORMED PLATES CLOSURE FLANGE RING FORGING = + EACH MAJOR COMPONENT WELD CLAD ON INTERIOR + DOLLAR PLATE WELDED TO TC:1'iS + DOME ASSEMBLY WELDED TO FLANGE RING' l + FLANGED NOZZLES AND LIFTING-LUGS INSTALLED + PWHT AS REQUIRED DURING ASSEMBLY STAGES + SURFACE AND VOLUMETRIC INSPECTIONS + REPAIRS AS REQUIRED + BACK CLADDING ON WELD SEAMS-l L + TOTAL PWHT (29 HRS AND 21 MIN) j i 1-i

9 .. Jk$$kk[M','# "' .. ~. FABRICATION HISTORY 2L-. . % fr,r g s ;.y g yeriu Prgi s ps" ~ rc (CONTINUED) y FLANGE TO DOME WELD + V GRC-OVE FROM INSIDE WITH OUTSIDE BACKING RING i + SAW PROCESS OF P-3 TO P-3 MATERIAL l + 25% WAS SMAW'BECAUSE SAW POSITIONING FlXTURE FAILED l + ADDITIONAL BUILDUP BY SMAW BECAUSE OF WELD JOINT MI'S. MATCH i { f + PWHT AT 1100-1150* F i + MT, RT AND UT INSPECTIONS l NEAD ASSEMBLY FABRICATED BY B & W l (CIRCA 1970) i l FABRICATION RECORDS (PARTIAL SEARCH) i + FLANGE MIS-MACHINED AT ID (THROUGH-BORED) i j + WELD BUILDUP ON FLANGE ID TO CORRECT' i + MAXIMUM MISMATCH 5/8"-AFTER WELD BUILDUP t j l + NUMEROUS CLAD REPAIRS OVER ABOUT 180 ' 0F CIRCUMFERENCE NEAR TORUS TO HEAD l WELD l i _ _ _.. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _. _ _. _ _. _ _ _. _ _ _ _. _ _ _ _.., _. ~. _ _.. _ _ _ - _. - -... _. -

0 h*% FABRICATION HISTORY 'i+TMEHEWPWt*'NE.mx5D, (CONTINUED) OBSERVATIONS AT QUAD CITIES

  • MISMATCH ON ID OF TORUS TO FLANGE I

+ BACK CLAD BY SMAW ABOUT 12" WIDE FROM I ABOUT 25" TO 37" ABOVE FLANGE FACE WITH HEAVY GRINDING NOTED + CRACK INDICATIONS OCCUR AT JUNCTIONS-OF BACK CLAD TO TORUS AND FLANGE CLAD + BACK CLAD APPEARS TO EXTEND OVER TOP OF PRIOR CLAD AT JUNCTIONS, PRODUCING VERY THICK TOTAL CLAD (ABOUT 0.5") VESSEL FLANGE TO SHELL WELD 1 + FABRICATED BY B & W (CIRCA 1970) + FLANGE TO SHELL BUTT WELD BY SAWT + CLADDING OF FLANGE AND UPPER SHELL BY SAW + BACK CLAD OF FLANGE TO SHELL WELD BY SMAW '~ + DEVIATIONS (FROM RPV QC CHECK LISTS). ADDITION OF FOURTH LONG WELD = SEAM-UPPER SHELL WELD REPAIRS OF VESSEL FLANGE = + CONCLUSION: NO MACHINING ERRORS OR MISMATCH

4 '8 G e % ' ' s ^ .m+ 'ek s_%. ;h .. s,.. ,y y. . g.., ._s , ~. - ' __ 4 %' 4 'e .c;,.,.. f i - s..., : y FABRICATION HISTORY m,v: su.w :~.m n,;;. : :

. u,.n (CONTINUED)

OTHER VESSEL CIRCUMFERENTIAL WELDS BY CB & l OR RDM 1 i 'I I I. i I l

,. '.~.. * ~ '= CLAD CRACKING BACKGROUND ~c e w g..c c c.m x.w.e+. 1 FUNCTION OF CLAD ON RPV l.D. i (LOW ALLOY STEEL -IS TO PREVENT CORROSlON PRODU)CT RELEASE TO PRIMARY SYSTEM TO : + MINIMlZE FUEL CRUD + PROVIDE GOOD WATER CLARITY GENERAL CORROSION OF CARBON STEEL IS 3 VERY LOW IN BWR DUE TO OXYGEN-IN WATER AND STEAM + TOP OF RPV (STEAM) MORE OX1DlZING THAN -j RECIRC SYSTEM WoT REASONS CLADAON RPV HEAD, AND RPV NOZZLE RADIUS (BWR 4,5,6) + NOT NEEDED FOR CORROSION CONTROL + IMPROVE U.T. CAPABILITY + IMPROVE FATIGUE RESISTANCE. in I'l '-

=W.a

, i n, '

^'..:~ CLAD CRACKING BACKGROUND 4 W y fy :-- g jnsg.. _.j . ;#, -' ~ ~ ~ ', y. 'a (CONTINUED) CLADDING OPERATIONAL EXPERIENCE TO DATE + SOME PRE SERVICE CRACKING DUE TO y CHLORIDES / FLUORIDES + ONE SCC OCCURRENCE IN SERVICE (MILLSTONE) + LOCALIZED WELD REPAIR INDUCED CLAD CRACK i PROPAGATION TO LAS(GARIGLIANO)-

  • ALLOY 182 BUTTER PROPAGATING INTO'LAS OF RECIRC NOZZLES 4

4 i

~ L - wr g. INDUSTRY EXPERIENCE L WITH CLAD CRACKING mwnz n.v. } L L GOOD CLADDING OPERATIONAL ~ (SCC) PERFORMANCE TO DATE l 1 l VESSEL CLAD GENERALLY HIGHLY l RESISTANT TO IGSCC + COMPOSITION / FERRITE DUPLEX STRUCTURE + LOW RESIDUAL / OPERATIONAL STRESS i i SOME CLAD IGSCC HAS OCCURRED i l + CLAD CRACKS IN (TWO OF THREE) HEAD I SPRAY NOZZLES (LP) l NO CRACKS AWAY FROM NOZZLES: = SLIGHT. PENETRATION INTO LAS = (APPROX. 05") LOW FERRITE <2% NEAR CRACKS = >2% NO CRACK REGIONS j = + CLAD (MONEL) CRACK PROPAGATED INTO LAS' (GARIGLIANO S-G) LOCALIZED WELD REPAIR CAUSE OF CRACKING + FATIGUE MECHANISM ALSO HAS CAUSED SOME CLAD /LAS CRACKING l FEEDWATER NOZZLES (MOST BWR 2-5-PLANTS) = = CRD RETURN NOZZLE - FEW BWRS l

INDUSTRY EXPERIENCE WITH CLAD CRACKING 1 - msg e w e.,m: c y;, o 7 (CONTINUED). RECENTLY ALLOY 182-BUTTER IGSCC PROPAGATED INTO LAS i + HIGH-RESIDUAL STRESS - NO PWHT. 1 FIELD WELD l QUAD CITIES CLAD CRACKING CONSISTENT WITH' SCC. EXPERIENCE + LOW FERRITE BAND (MILLSTONE) + REGION OF HIGHER RESIDUAL STRESS (GARIGLIANO) i + AGGRAVATED BY SEVERE GRINDING. + HIGHLY OXIDIZING UPPER PLENUM REGION-(MILLSTONE) 1 l

,,6 c --e - -- ' - i '-- -g

  • ag; V FRACTU.RE MECHANICS ANALYSIS Oa

..... 3..

.M wm1 Reg!gEt.*Nttis52EEpfi CAUSE OF CRACKING l

1 - + METALLURGICAL CONDITION [ + APPLIED STRESS + ENVIRONMENTAL CRACK GROWTH SECTION XI FRACTURE MARGIN ASSESSMENT + ALLOWABLE FLAW SIZE + CRACK GROWTH ANALYSIS STRUCTURAL EVALUATION-OF GRINDOUT REPAIR + SECTION lli PRIMARY STRESS MARGIN POSTULATED FLAWS IN THE BELT LINE REGION

I CAUSE OF CRdCK OBSERhAYihNk me Imssereurn=a.sur J CRACKING IS LOCALIZED AT OR NEAR BACKCLAD INTERFACE ELEVATIONS + REGION OF HIGHER RESIDUAL STRESS CRACKING GENERALLY-CORRELATES WITH LOW FERRITE MEASUREMENTS l + LOW FERRITE AUSTENITIC MATERIAL SUSCEPTIBLE TO IGSCC FERRITE CONTROLLED BY COMPOSITION BUT CAN BE LOWERED BY DILUTION AND HEAT TREATMENT REGION OF CRACKING HEAVILY GROUND DURING FABRICATION GRINDING (COLD WORK) AGGRAVATES INITIATION + APPEARANCE OF REPAIR AT SOME BACKCLAD-l lNTERFACE REGIONS HIGH RESIDUAL STRESS / LOW FERRITE + AGGRAVATING FACTORS l COLD WORK (GRINDING) + LOW FERRITE + POST WELD HEAT TREAT CAN PRODUCE HIGHLY'IGSCC - SUSCEPTIBLE 308 CLAD MATERIAL j FABRICATION SEQUENCE AND BACKCLAD PROCESS i UNIQUELY CONTRIBUTES TO IGSCC SUSCEPTIBILITY

l I l ,0 p0 /80 2"{0 60- =7.3/7.8 + 5.8/6.0 o 3.4/4.0 65.4/5.5 \\ i 48- =4.9/4.6 + 7.0/6.8 o 4.7/4.5 o 6.6/6.8 { 4 40- =2.2/2.6 + 6.6/6.4 o 1.1/1.3 o 4.0/4.0 { 36 =5.6/5.2 + 2.1/1.9 o 2.3/2.2 63.2/3.4 34' =1.8/2.0 + 4.0/4.4 o 2.0/1.8.

  • 3.5/3.5 32-

=4.1/4.2 + 2.2/2.2 o 4.0/3.6 = 3.2/3.5 { ] 28< =3.4/3.3 + 2.7/3.0 04.4/4.3 > 3.9/3.5 26 =3.4/2.7 + 4.2/4.2 o 3.8/3.9 63.3/2.8

24

=1.4/1.2 + 3.7/3.4 o1.2/1.6 61.9/2.2 - 18' =2.2/2.3 + 3.6/3.6 o 3.5/3.4 62.2/2.3 i 6' =2.4/2.5 + 3.1/2.9 o 3.1/3.2 >3.8/3.3 6 FERRITE. READINGS AROUND TOP: HEAD 1 =--. ~.

1 y on a 4-ie-n io:n i e c as. ce 11 O mA C&es 2 L W.J C.l AJi=. 4/m/9a l ur. _ Mb DaL. 'ai c.:4A. .vh L L L uv.2_o,jL. er 1. e T-W2

  1. 2,1
  2. 22.

H 91.ea uk o,t h.t h _ s g h.s 3.Q.9 x m c ,x c > n r.sk.1 2.1/t3 4.5/u 5 x x 3.3/s.3 2.g/a.6, 9/4.o Laajs in FN (Fea hbed

14. T q / 2 4 M ';

I st. Ren4 % terse to Ws4 %ds 2 4 LAig ba het +e WeLA BeeA. 9 D 5

Q GEnkdnerEnugy N,' Epineering Calculatio a,,, Q J C h 1 T.,H ak cluutu L.,l b..4 dieo /s / l Fwide. LAim at Gw'd ut.s " x +.f ~ ,,, 2.,, _1._ a> O' (W.3)

GvMe, c

)q $ '6 q s.s/s & -3 3 1 a iX, l

\\ f

.xp l - r. f' $N

{

L s.4 /s.4 . l.r/t.s I x x x 1c o.7/e.s s.o/*.a L = 4,, e. -n ~. r,, x t L s.ste.1 i i J'. N. a s j; t' i 4 T hut.w

  • 18 (cweawei a

i J t sts:t ,.oh.r x x n I ' ' /} k l ] p7 x \\x. o ][ j%/).O l Afg/p,g X ~ r g

  • '/2 '

s.s/s.r - 4 d f .c l' 1 1AAB/261$6} m FM C F :r6t Nebsy) 4%d4 g ht My h + w. irs. 2, m3 2.4 by Pwmm.t % wetA 13..a.. L .u. 2-..

~ ~ \\' e'I' ,,\\ ]H -il\\ ~ -t y3 a 3 ' 3:lt ' l T ~ 4. 'W 7.;..{ q M,WpWj { *, * " . b ;z. APPLlED STRESSES i wr . 31-7 :.n o m mm/smmess,mp,,... , y) '? ) j , r' \\' s 1 : BOLT UQAD '$ TRESS t. \\- i .k / 8 l t

- 1 S.bHESSURE STRESS l

i / r' ,x 4 (' I i, I > // r j a t CLAD MESIDUAL STRESS s. 3 , \\ , i ~ 5 I ( i\\ I, ( SEAM WELD RESIDUAL STRESS \\ I, ~ lj 'I j 'g i / s ,,.} l' \\ (l - s s, \\ t /' l 'f i g e; f; z, /s 1 > ',/ t t n 'l \\ t. y \\ / 5 { f-j i ', e \\ i , A / b } N _b 44 / k, 1 I 7V, { q p, , c' s'- r,f f i. / ( 1'

g.,

3 ,/- / e u ,o. f, .),, 'k, ['3 '( /, ,( \\' \\ \\ s,\\ j ,) l' ' > -, 3 ).s. /. t' e>( i ( h ~ h.' h :.., .f N _'- _.f ' -

7 f~ "!I l'

5.,.

STRESS l.N THE REGION OF THE i INDICATIONS j 3W t c"~& # %. G ; %.5nt.1 %, 2.:s. i APPLIED STRESS DUE hO THE j COMBINED ACTION 01: BOLT PRELOAD l AND INTERNAL PRESSURE BOLT LOAD PRODUCES BENDING STRESS WITH THE i INSIDE SURFACE UNDER COMPRESSION i l PRESSURE STRESS IS MOSTLY MEMBRANE TENSION j STRESS (15.5 KSI) l l BASED ON FINITE ELEMENT ANALYSIS, i THE INSIDE SURFACE STRESS NEAR THE INDICATION DUE TO COMBINED PRESSURE i AND BOLT PRELOAD IS UNDER 5 KSI j TENSION RESIDUAL STRESS IN THE BACKCLAD NEAR THE JUNCTURE WITH THE MACHINE l DEPOSITED CLAD COULD BE HIGH + LOCAL WELD REPAIR HIGHER THICKNESS OF BACKCLAD (LOCALLY UP TO 0.5 IN.)

[- CSI NUCLE AR COMPANY , 'bOCT-LTP hELo@ "pgg % TRESSES )* Q + %t cpr-C'e-pd No. CVSn (KSO (K6b y -29 5@9,9 f g. .[ - 10.B5 2.m o g y '22.,\\ i g.gG. l 2-10,85 9.07 o / %A2 5 -15.21 0.9R9 0 al' yo ) L 0 l y\\s\\ % 4 L5.2L LO. A L ^ L% J , 16 M2 6 - ao.2G - i. AR o PT - / 17 ' j S. iSE.C, G 2n.2(., LO.78 o gg, t M2 9 -15.9l' -9.70 0 ) Wo.o A 2.5.91 10.R4 0 W Q -23.52 -9.4B o 45 bl.O to 2ss2. 943 o / N . %t.5 it -19. LO ' Slo 9 o H S= 2.0 il 19.1 0 7.17 o bts v3 -iM 20 -i7 R7 0 t s=s.s . tg is.M -B. ii o M1 is -is.32 - B t'n o 7 $94.0 102 -4N7 -6.07 o L3._ t.:: %tct 17 .-e/M -1.'1B o g/ 'l S ca.O 16 91%2. nA o ? M9 19 -AG.% -0.@91 0 h u.t so m.m 92.6h O

?

% tto. ei !.025 R.E4l o g b*lli.3 22. -0.53l G. N O 3 --h [p 11 q %ti.o 23 4.2%i 2.54R o 1 9.c 5_ _g M24.3 M l-9.M6 - o 4 11 o v' $',3- -4 htc 25 Loss -o.22'1 0 1 &r34.1 GG -1.29 0 -o.919 o LV -2. hHt.1 21 -E.1M ' G. lit o 1:28.0 26 - L2.22. 3.%O o l w,,, 261"'huYR-I'o d4G i UNC' Duc. l - ( $*g iw w *-' W. " bl ) c

CBI NUCLE AR COfAPANY f STEAL 4 OJTATE LerATION D ESSES ,gy + %t Cp Ce cr ,[ d. Wo. (G0 (KSQ (KGB E's 2t - b *9 e 1 - 3. m2 11.8 2 - 3.o5 -[- O AD -22. g e l, a 21.52 25,27 O at-6 GT a - G.98 1s.e1. - 1.os 2o 4 25.20 . 25%. O p ~.1 S -inA9 15.10 -1.06 t1 =125 g G> 29.19 25.15 O El' / BB 2 1 -1s.oa 9.sg - 1.os KO.c ?> m.ao a+1n 0 9 -ds.RI 9.327 .f 06 g s1.0 ta ro.% ap to9 0 l'~ ~ iG, 5 11 - 9.5B 9.92 2 -Los 5'29 il 24.47 en 14 O + ' RPets G -2.37 -4.o4 -f.o s +:4lbs.6 n is.o(o L.2d o .i 5 t6 l -o.2?6 sa% ~ 3.0S WO \\ G> - 7 c4 i.4n% 0 ~ g_ E 9 17 - 21.4 s AM - 1.o 5 / B 16 ss w. sNm o it \\R - 2c.ss il.42 -1.06 A ao 65A9 EM o 10 2i 14.2Fi 2 2.12 - f.o6 il .3 22. (s.sb 2nB9 o ? d Y 11 ~ i ? 1-S. 23 17.9 7 M.1B -1.os 5- -G D RQ4 12.97 O b 25 14.cos 13.s3 -1,os s- _4

  • 2 2G 12.20 19.E O

L-7 7 27 9.(42 19:19 -1.05 G .0 26 _g o$ K79 o %-- 2543 gm_ c, Ed' MC, ' " * " ~ ' - 4N(o c, :-' l'7 a S l. s.

9 4 g C w l i km E'A ?. rr s M R M I N25$$$ 27dIEE7 8 g IDkbE$% = am-mm .erm bE -i, 6 'm (n e c~ U l X ~ ~ - - - - - - - - _ _ - _ _ _ _ _ _ _ _ _ _, _ _ _ _, _ _ _

1 e 4 4 e v* Wd TT. M h,. E 6 {*t?b5W*05:3Pn EhkkEE?. T !! tat?T s E l W m d 2 U L

1 4 -e i irr v i b' g 8 -w n -N E i i i i i i i i i i i o ~ 9 m h e-9 n N o o o o o o o 6 6 6 TN'M 30lSNI NO SS3815 ONION 38 3Al103W I i 5 l

l__ l l 1 i i MPov7i 20 30 40 50 60 70 80 90 100 110 120 1 I i i I I i i i i Meerwc4 ano assene mAcx peopAsanow nAst/swess httwatt 10' ' II { RELAhtertmet FOR A&33s/At00/A10s av 200006 OrveDeAftD # Aft > i = ~'N,0 feQRN 9 NALL MCWETT a BAWs i 8 9 KEETT ) Id 3 e $ MALL K NETT. C' Tom t M I g 10~ ' I E. O l.60AD0m 0 0102 RA,PMua = 2 i n 3 3 400mvehe = 3 = y Iss \\ MORCDCAL / gg4 Low Subewup g 0-, .= UMIT UNG tt0VAf@v 81 = ( = ~ (J G8 OtSPOSIT108v UNE Poa CRACKING (80VATION 91 E 4 b / '= +8 W = 0 E 16 10'e r u pic g "+~ 3 T/Wett *?m"# U

  • we anoa meansaw a:

/, 0 o M 1N e '+ r l 0 +M, 3 u p + I 3e i I et i i i I I 20 30' 40 50 30 70 80 to 100 t10 ' 3gt %p 9% A STRESS INTENSITY Ksk/n 10 Figure 29. Theoretical and observed (64-72.79) crack propagation rate / stress intensity relationships for.01058 steel la oxygenated water for corrosion potentials between 0 and 100 aVsbo, i 320 .. -,, - _. _ _ ~..., _.,.., _.,.. ..,.,_.,..,.._......._...,..u... .m,

4 2 1 1.9 - i,3 TIM E FoR CRACK 6RotJT u T.8 - (N CLAD 1.7 - 1.6 - 1/2 IN Cup ~ 1.5 - 15 KSi 1.4 - 1.3 - -z O 1.2 - [ 1.1 - Q i-r 0.9 - 0.8 - 0.7 - --- - - - - - _. ___-v 0.6 - ~ o.s - i gopoo : ,3opoo u,g

  • gg hoee'5

./ ,'/ 0.4 - o.3 _ a2 - i O.1 - 0 f3 o

ao en cemden mc Top. Head' Crock Growth for 1 2 in. Clod 15 ksi Clod Stress i

a y -

s

.D., ". J.' k sd ;:.*k<..^. 3.- 0.[Yb E-M ^ ... :. f ' .3 E ^ f. :;.w.r ;,'s. f :. ;.; &.r :..:.

n. -e...
9..' 'i. a* : *5 ' ~ A," - I d k~i

- :. u....::- : c.:,. =.y:,... ' ^... :z..: .'.D ~- , ?.. ! :s - :;- c-c .*x.--g e-

, w.

- c.

r. n.:.-

- gt -2 I .. I:; : 5-?.sv d ,j ?. - 'b. : f 4,}'.";.[y:..E ~. . $3 r - f[ 49 f E: *': . ~ I"

ny4 .o.- . ;3 ; j,.. 3 m, ,., 7 SECTION XI FRACTURE MECHANICS EVALUATION ~"GWMPFHP?GHr. . +._ T ' s m n w n t i s.c g i7. ALLOWABLE FLAW SIZE AT LOCATION OF CRACKING + BOLT-U P + PRESSURE TEST + NORMAL OPERATION + LEVEL C/D CONDITION ALLOWABLE FLAW SIZE AT LIMITING TOP HEAD LOCATION i

l 1 i 100 P = 1100 PS i I 90 - 1/2 INCH TlWCK CLAD 15 M9 CUO STRESS k 80 - deg. OHCUMfERENTML ftAN w RTndt = 12 F .x v .l C o ) i h , l e ~ 1 i_t- ---. - ES..T T.E.MP =.. 185 F (Kf o=_181) ___ ~ E m-M Z l (Q - m i gpg 8 :? w E .w -

e g

7.k k ~ i j 9 e 20 o .i W-l j 7: o-o' l o ..o.2

o..

.o.. . o. 3 i7 ..i 4 c .moc o&m (6.).. .K vs ~ o for. Pressure Test Cdndition, Crocked Top head Re9 on i + .,. a. . <~ ~ e '.),b

g. 1. I,;g.."..:*..-

b j . 1.1... .w g

  • O.: * - 7. '

0.. . *..., R.;.. r

- - [

.. r.. .. ;,. [. g,. ;7f 4 ';........r .Y ;.f..>;*

s. *

.,,,. O... ;.. ;. ;..~. ;.. ' 4 s r. . :j.. ? 1 ***.. ....O. . k h... n....,f ti!' i s ,.- ; g,'. ; :,, .w.....; If. ft

  • g...y x.-.. <..-

g -

  • l: I h.,. s.,

f, ,+' * ( .,....,~..,. I ........-~ ....hkIUNNI.f45![.w I 4, i ...3 <w. m mm. m m

Lr-100 P = 1000 PSI go _ 1/2 8MCH THICK CLAD 15 KSI CLAO STRESS Itc so - 360 deg. CIRCUWEROCIAt. FLAW s RTredt = 12 F' .x er m 8 ALLOm8LE K =_63.25 MSI Al r o =- d M-g !g so - w -z g-nn i8 6J

(

f 30 - i i T - ussos: b R. S - i(w

10. -

I. O o . p - c.2 0.4 c.s c.s -. k. a ~ 1.2 1.4 1.6 T8 2 .c v. mgg

  • F.

.s ~K.vs o for Norrnal Operation, Crocked : Top Head Region ~ I: .O .. n:.. (.. s ....... r... w: e. ..:..:....c. :.. .s .,..,..3.. c.

3..

n.-..,.,. .. m.. . M.- g 1. p Ay.:'<. : ... ~- :. ...., ;. ::- :: : :,~.;.' ;. :..Q..- - { n.., f f.; ',. . :;.n , *., * : g

  • -r C,
  • ; ;...g e'

. ~ Ln.g:,f.: :y,.3. ~4 : .c e.. . ;.,r :;;-.... . J; '.a ?. * -. : p.-., ' - < :. 2. ',, '..

6 D -

, " f. * .L *.

.5, :

. ** :: 4: ".,..,.

9. s.
  • t:~,.. x :., g~..'..e.y.a;
,3y;*

V..;- r .m..s_.-

i e I womammmmmmmmmmmesm w me e s e.r._.' l HIGHEST STRESS TOP HEAD ^ L0 CATION . +;m w c1% 2 cit &ab =:: l J l' PRESSURE TEST CONDITION l PRESSURE STRESS = 17.3 KSI NO BOLT UP COMPRESSIVE STRESS q i + CLAD STRESS = 15 KSI 1 l l 1 'l I a .i l a .J s . _ + - -.. _, -.. -...-._....._-...--.,.----..--.,__m--. -.__._..-..-___.-_--,..__.._,,___._---.._-.-_....-....-----.m..

'r j 100 l P = 1100 PSI [ I 1 go _ 1/4 INCH THICK CLAD 15 K9 Cl>O STRESS k 8C - D U E* s RTndt = 12 F i 6 NO BOLT-UP COWPRESS:VE STRESS M -~ g c NORM AL ~ 'E R AT ION g D t.1 in. d 60 - TEST TEMP = 185 F (Klo=181)__, i s (.Co SAFETY FACToft ' E M-5 M i I i i e m w f y _- 5 i y = 0.865 IN m 0 B m-10 r. j + i: 0a 3 3 3 g g 5 5 5 5 g g g g 5 5 5 5 g i ~ y 0 0.2 0.4 0.6 0.8 1 1.2 1.4 - 1.6 1.5 2 CRACK DEMH (m) ~ K vs a for Pressure Test Condition. Worst Case Top Head Region .m W re = .o-= m-s -e m m...m mu __m,m.. oi

m 2 1.9 - 1.8 - 1.7 - 1.6 - 1.5 -

1. 4,

1.3 - mZG 1.2 - d 1.1 - 1/2 W M 15 K9 a w 18 - do = 0.046 rn. o 0.0 I yf 0.8 - 1I

0.74 b in -

J o7_ I 0.6 - 0.5 - -. 3 0.4 - 0.3 - 0.2 -- dt=16 months =11,700 hrs ?.: M 0.1 - i 0 D 20 40 60 80 100 120 ~ TIME { OPDIATION) Top Head SCC Growth Predicted for Next Cycle of Operation .i.,...aeu a .--..-. ~----

FLAW NCCEP kkhh A$bAk ON w s m g;y y. ~..yn.. ay. ve ~. ~ l l ALLOWABLE FINAL FLAW SIZE = 1.380 IN. ] i i i ~ j EXPECTED CRACK GROWTH FOR 16 MONTHS DUE TO SCC 0.046 IN DUE TO FATlGUE 0.01 IN (10 STARTUP/ SHUTDOWN + CYCLES) 1 PREDICTED MAXIMUM DEPTH AT THE END OF i THE NEXT CYCLE = 0.747 IN. 0.756 CONTINUED OPERATION ACCEPTABLE FOR THE NEXT CYCLE y i i 1 l 1 I \\ j l l l 1 1 <A

Wmiw+11v. hi+da.mJ.U LEVEL C p-cu/D CONDITIONS

r. :

.:, e ~ LEVEL C/D EVENTS INITIATE FROM NORMAL OPERATION (T=550'F) AND IN ALL CASES RAPID COOLDOWN OF VESSEL IS ACCOMPANIED B RAPID DROP IN PRESSURE PRESSURE TEST CONDITION, WITH HIGH PRESSUR AT LOWER TEMPERATURES IS MOST LIMITING CONDITION I

l e

l-1

s m w m e w - x w. w e s w c a r. w n :

STRUCTURAL EVALUATION OF GRINDOUT estmanamusamme wn t. c.s..r 4<.Na w : l l' MINIMUM REQUIRED THICKNESS = 3.08 IN. l ASSUMED MAXIMUM GRl'NDOUT DEPTH IN LOW l ALLOY STEEL-(AT LOCATIONS WHERE BOAT I SAMPLE WAS TAKEN) i = 0.5 IN. l 4 ( PRIMARY STRESS AT GRINDOUT (T= 3.5 IN.) I, + DESIGN CONDITION i 1 l 22.3 KSI < Sm = 26.7 KSI 1 i ADDITIONAL FATIGUE USAGE DUE TO NOTCH l AT THE GRINDOUT IS NEGLIGIBLE 4 i s' I' i l ... _.. _. _.-_m..,_ m_...,...,_.,,r ..y. .mmmy,ywy.,...,,w.,,,_.

..i. fs so /sh vs'csec zpn k as.s 4

4

~ gre,sp,S S f c./876 = /2S. 6376 in. ,0 c /2 s~o s er. f.\\ s,.m 7sosu

j. y a

f,. :' .<A.e# n P.C ffro)(/25 68 7S) s d. e 2 5,t a 7. d "- ,-lj,* % - o.S P s .t J4, 760 - 0. *C G'2fd.) i l' df,e.,.s sip,r7#suosee - <c. c4 2S in, s .f f-T' C '.b o d,.e,;i &.oas.rm.o62s -- S. ca7s up. i l32 & /_/se &,./2S ur Safe.*/V l R7 E.' j Ys.7////* krs//d?.e.5 d'r' d l5 / '4 j. i P/2 (i2 SoV/PS.4875) l.~ if fi 2$

  • pSen - P 'c2' K24,760)-/250
  • E' 0 '

S '#' - ..:. u. _.: =. r.-.-

1. t :'

E $creos soer A//ou.)osee c 6 047Citr. '1 :.j d,,,y c 30 /26 / 0,06 2 5 c.S' 0 7S/ in. .I d./sc 4. 6oo ier z.A.,rse, ,//e.i</ 1 2.' Abc 3.oc>o in D a>e< 6,f.u/

s

', ?) $ ~ /!f?mir asrr tepuieeW C/s $ n !$,~o6a/ in ord/ /l <A b. A ce<7s.W.s / o's wraab rode /s, $!co'g i.sw. // 4e a:./m c.3 m lh $,1 V' '// sistec /$oe.?<>es: e.s/r Inf.an. '3 L W i l D..C1'? e 1.w4:f'*.c.de _Z: f J & c./s 4es T 2 O r.) ~ W. X COMPAliY~ WENT nA rd.es wt 1.' k.. JOU No.. t T. SHEET .7-0. ~ l) l- .-...m ..-..-_.,..,___-,_.,-......-_,_.,._._..,,,,....,____,.r_,._,.,,

ummmmmmmmmmmmmmuness-sar i EVALUATION OF POSTULATED FLAWS IN THE BELT LINE REGION \\ .. ? ) M 2 ii k N i n s + 5 a '.! A L C L 2.. L i ' '=' l l EFFECTS OF IRRADIATION EMBRITTLEMENT INCLUDED l 1 l CLAD RESIDUAL STRESS IS NEGLIGIBLE 1 i + NO EVIDENCE OF WELD REPAIR l NEUTRON FLUX WILL LEAD TO REDUCTION IN CLAD STRESS l I PRESSURE STRESS EVALUATED l CRITICAL FLAW SIZES DETERMINED i i e j

w ..n go ~ R p y ..H a) s m x ~ M u* . C. i U ~ CD C n O c c bo O 8 m O 00 (/) ll

  • d Q

m b R e o e L -g= u e a g u o; 6-u E f b g ti u u Da o o No, ( m l e: -o i 0 t I i i I 4 I i i p O 8 8 8 R 8 5 8 R 2 (ein) WO10W AdlSN31NI S$3W1S W101 I

100 i P = 1100 PSI 90 - 1/4 lNCH THICK CLAD 0 KSI CLAD STRESS AXIAL FLAW. a/21 = 0.5 t ^ IE 80 - m RTndt = 82 F AT 12 Fli>Y ? 5 i! Y>g so _ o e.- i so - w z;; 40 - c i N-198P=185 F (Klo=83) ---, t e"- i i 10 - l 9 = 0.800 IN i f. o O C.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2. CRACK DEPTH (in) K vs a for Pressure Test Condition, Beltline Region 9 a e-- a-2 n w-. -a w --.re-- -~. - ~ z>-. -. -.2 - .a- -n.. -x a- --.----.a

Qf, ' slin f: ' g g f% =TT'.".;h '; e ~ 2, 3 +}i fi' u. u. CRITICAL FLAW SIZES BELT LINE REGION . E ih M W D.-d.id bi 3 C. M i H !E G U i k - 2 THROUGH WALL CRACKS EVALUATED AXIAL CIRCUMFERENT1/.1, =_ PRESSURE TEST 8.3in. 33.2 in. NORMAL OPERATION 58.7 in. > > Large HIGH FRACTURE MARGINS EXIST INDICATIONS FOUND THUS FAR POSE NO FRACTURE CONCERNS EVEN IF POSTULATED IN THE BELT LINE

l I

4...

..,.. wommeneet:.2.n OVERALL CONCLUSION Ju m.u s w JeyEd..r.4 \\ l ,i i SECTION XI AND SECTION lli MARGINS i MAINTAINED i i i l i 1 i i CONTINUED OPERATION JUSTlFIED FOR THE i i NEXT CYCLE i i l l i 1 4 I 1 l i 4 h i 4 i 4 ~ -. - . ~. ~

l. l ACCEPTABILITY FOR t CONTINUED OPERATION w ammmmmmmmmmmma m es m s, w mass u oser w +- l l

SUMMARY

l + VISUAL EXAMINATION AND SUBSEQUENT UT AND PT EXAMINATION OF REACTOR VESSEL HEAD i CLADDING HAVE REVEALED LINEAR INDICATIONS l lN A CONCENTRATED AREA AROUND THE INSIDE OF THE VESSEL HEAD + THESE INDICATIONS ColNCIDE WITH THE i BACKCLAD REGION OF THE FLANGE TO l HEMISPHERE WELD 4 + DELTA FERRITE EXAMINATION RESULTS OF THE HEAD CLADDING SHOW LOWER READINGS IN s THIS BACKCLAD REGION l METALLURGICAL RESULTS OF THE BOAT, SAMPLES i SHOWED PRESENCE OF STRESS CORROSION CRACKS IN BOTH CLAD AND HAZ OF BASE METAL + IN ADDITION, PRELIMINARY' RESULT OF THE SAMPLE TAKEN FROM A LOCATION IDENTIFIED BY UT, AS CONTAINING A SUBSURFACE DEFECT, j SHOWED A POSSIBLE CRACK IN THE HAZ. THIS TYPE OF CRACKING IS NOT CONSIDERED SIGNIFICANT OR OF ANY STRUCTURAL CONSEQUENCE. l i . -, _ _.... _.... -.. _. _ -, _, -,, _... _.... - -..,.,,....,.,. _. ~ _,., _.,

j i ammmmmmmmmmmmmmmmenw::mmmmenscun A.CCEPTABILITY FOR CONTINUED OPERATION ...ss.ammmmmmunessememauer,- l CAUSE OF CRACK OBSERVATIONS BACKCLAD INTERFACE ELEVATIONS ARE A REGION OF HIGHER RESIDUAL STRESS + CRACKING GENERALLY CORRELATES WITH LOW FERRITE MEASUREMENTS o LOW FERRITE AUSTENITIC MATERIAL i SUSCEPTIBLE TO IGSCC i REGION OF OBSERVED CRACKING HEAVILY i l GROUND DURING FABRICATION i i GRINDING (COLD WORK) AGGRAVATES o INITIATION OF SCC ] l APPEARANCE OF REPAIR AT SOME BACKCLAD + l INTERFACE REGIONS j HIGH RESIDUAL STRESS / LOW FERRITE o l AGGRAVATING FACTORS i COLD WORK (GRINDING) + LOW FERRITE + POST j + i WELD HEAT TREAT CAN PRODUCE HIGHLY IGSCC SUSCEPTIBLE 308 CLAD MATERIAL. 3 { 1 i

(7 6

a....

a, >;,,.. ; 4_, ,;,. ;. _ a : a ;,z; 7,;.< ACCEPTABILITY FOR CONTINUED OPERATION . ypE ;.. y 9..; ; gi.:;;5.g M M. m :9hMw234Mgity *.n ' CONCLUSIONS FOR CONTINUED OPERATION STRESS CORROSION CRACKING OF SENSITIZED AUSTENITIC STAINLESS STEEL HAS BEEN OBSERVED IN THE PAST THE DEPTH OF THE CRACKING HAS BEEN DEFINED BY UT EXAMINATION AND MEASUREMENT OF EXCAVATIONS PERFORMED ASME SECTION XI FRACTURE MECHANICS + CALCULATIONS HAVE BEEN USED TO PREDICT CRACK GROWTH OVER TIME + HYDROTEST WILL BE PERFORMED IN ACCORDANCE WITH RG.1.99 REV 2 CODE MARGINS WILL BE MAINTAINED DURING THE + 4 NEXT OPERATING CYCLE.

,n ~, i i; ' I, j / \\ ' d or s 2 . m u s e a m m e a s. a m.

> ~ i FUTUR.E INSPECTION ACTIONS l

l . n. m

  • w;stM k w E *. !WE M seis1YE. %.

THE FOLLOWING ACTIONS WILL BE i j -/ IMPLEMENTED: l t COMPLETE METALLURGlCAL ANALYSIS QUAD 2 BOAT SPECIMENS o l REVIEW FABRICATION RECORDS FOR SIMILAR + FABRICATION ACTIVITIES TO IDENTIFY TARGET REGIONS FOR INSPECTION t o QUAD 2 VESSEL QUAD 1.-DRESDEN 2, DRESDEN 3 HEAD AND o VESSEL i ESTABLISH EXAMINATION ACTION PLAN FOR j UPCOMING REFUELING OUTAGES; i i j DRESDEN 2 (SCHEDULED 9/90) [ o QUAD i (SCHEDULED 10/90) o o DRESDEN 3 (SCHEDULED 3/91) J 4 i ) QUAD 2 (SCHEDULED 9/91) 4 o i I

Q,7 g'j- {25 'i l f a y) Q 'f h steammmm{usement,mer.amesamu mw < ),W, y -[ J Ol',2fUTU45 INSPECTION ACTIONS f& As h h wanesa m m wo ,., e ' \\ } ,i.' ] Y,, 18gd.+ x ,\\ OLLQyUdG ACYL,[nlNSMREAUBFIENT_LY 3 J 3 UNr)!iR DONSIDERATIOM;. N ,I. '( \\ e ,- /'q / .l.. J ('] ,/( Pijf FORM F;/ilTJE EMMENTcGTRESS ANALYSIS TO p \\.\\ pVELOP, INPUT FOR FRACTURE MECHANICS f ,D a 1' ' DEVELOP IMPROVED EXTERNAL UT TECHNIQUES + EYALUATE REMOVAL OF CLADDING IN TARGET REGIONS OF HEAD BASED ON RESULTS OF SUBSEQUENT o EXAMINATIONS, DETERMINE WHETHER CLAD REMOVAL FROM THIS REGION ON QUAD CITIES UNIT 2 VESSEL IS WARRANTED 1 1 1

} INVESTIGATIVE TEAM CORPORATE SUPPORT Richard Tuetken - BWR Project Manager ] Engineering and Construction Department y George Wagner-Manager d Nuclear Engineering Department Rorn Gaitonde-Metallurgist j Systems Material Analysis Department -j Russ Tamminga -ISI Supervisor Engineering and Construction Department g Tom Spry - Welding & Material Engineer Nucisar Engineering Department i Bob Rybak - Superintendent [ Mechanical / Structural) 2 Nuclear Engineering Department Brian Wilson - Chief Levellli 4 Systems Material Analysis Department STATION SUPPORT Richard Bax-Station Manager Gary Tagatz-ISI Coordinator-Technical Staff Chuck Moerke-Supervisor Nuclear Engineering Department (Site Group) Tom Tamlyn - Project Manager Engineering and Construction (Site Group) Curt Smith - Supervisor s Quality Control

I' Commonwealth Edison Company 7 -.] Preliminary Metallurgical Evaluation of the i Quad Cities Unit 2 Reactor Pressure. Vessel Head l 1 April 19, 1990 l 1 I c t 1

+ e 7 , ;#7,;. .;y p. { 4 '..:.~7 ;. 4Q.T '~~1"~~Tl g ,,l J- .],;.,,-.., v,, p j ,, i ;, h <l . f s,, ' ^* 4z.;. ;~ Q- ' f [ m: * .j l ['g j =, 7, w

i.

m.. + 'I l .O z f, .a 3 jg. -. y '.,j. ~. )7_ s y ,,5 e I N h. y'y

  • s' '

. m,' } .J ~ >, . yty ,,r gt y ~ e ~

r. y, h *s

= o r 1% + - { ~ 1 _r b [, \\ 'M;. i ;4, ~ a a f,i * .t.gVff L ~ -Y-[p, .V . 4 .3, s f [ y, y NW hgs, i,. .d'4. ,[ .g qg -Q[ ' q r f- , ~. ~ a Boat sample 1 - Note the hea'ry gouge on the lett side and the crack on the right side. %Wq h 2 +. , g sc

r w e.

u >;;,aw: -nw.m.VWm;4 jes,~ W' p&?;Q m; s' y n-n..s .g.T: ,, p qm _ n s-4 , y up. ~ 4 .. p w m+-- ~ ;_-, t. jf. m47Mw - 1 - 44gn;;, $" :', .#$w 7 6* . 1,

4..

p4'g{

  • Q..

,V" MM;45?' ' f g ~ c.sS$N@r gqEp;. ' ogye-g42 g t pCf

plylh.U[

p ys

,;g, s 3 v..,

y9a- !i.we: L Ml;;k Croso section through the gouge in sample 1 (Section 1-2, Prj% 10x) {t.g. ry 4 ,4

.. 4h

-%i_' Q, w G j.ip % M>.c6"'.R,;.QM "p/P$-lgl.1 . "'t t,... h.. ?.!i4[ Pdj*?fpypA m. q

r ~ 1 o

nl. l'y'~,

[ .,fG N .k \\ A: .s \\ ' Wy"N '-:$@4::g $WYY;*) i ft a vw ) h;f. Qil;[., L' t i$

a g

y,, A Y

  • r 4. ih[x ;

p. J ':.k 4,$. l

+

y3.x A)e k l' . p i.,; 4 w\\ .... g r4 r

  • w.,,

s.

?.

.$$y <,:. y v: - r...

t. g..4.%,f W,x.- VV-w q %% + & %k%

? t ' b j,j. - ,r a s.

g %![(Q p s.,,

't ; M. 'v- '$ f, j j b.$, ' e...< s.% r; .t1 L l 314 4 l .:.. s n.<

9 m

<r g: _

  • f.,,(l,pi '

, \\; s%r;

i a

~i ..-7 \\, a ~ n>e) *flA +g% ..~,.y q a e j' v.. wn_ ,y

f. V_ihA, n',gs.,'6$,b.

i, 1> ( e e " Q j..qp tp_:' x n t .,4 . p% s ",. v+: .,t, gy s .-._y .. s,, y ,t . ~...j g < y ( . ',...p ~ T.. Y / ~ ..._3 j Crack initiation in section 1-2 (75x, 10% oxalic acid: Electrolytic Etch) l ... '.,h. c. . L: *: %.,, ; %,t;, Q.p... ( ~ .[...jh r7ku", , 5f h.. ) .,y_.; .g. &m&.s.. h,$p,.s.., '.lm.';

b... 'hDh$'E:

1 r. .m, hp h h '.h.. 4... . A w.. N- . m::la: .N rep... .'C@W,4dp 3 t,e,f. 3.;p;.:,.%:. . s,at .,<,.e i;;ra.. - og.. t jyy. w. .3 9d.,O e c . f,,*A .'e* = p t - ,.'? xY,zs+% 9 & j ~Q i ff'frMW$$$ ~G4

  • nt S,h g

k n.,%e e4 D 9,..! ;;p W h-2f-N.. _ '3 F,#cm g,. - 'w. '1 MbD. I.-_. n. Cracking at the cladding-base metal interface in section 1-2 (75x, 10% oxalic acid: Electrolytic Etch). I

o e .:Q$} l. I .t m 'f,},y(it;fye $."jj/h e[t j t _s, .e; f ,. w ,3/ 7 l

~

4 73 j . w. $ 15$.$?$ pf h y c w.c.5 N:", ~s v. 2 ..q~.. Jg. : V z 9? . g;g,' _'i$kI, dC' ^ s. p* g , W>*91 9?: = An unetched 'r1<, f the cracking at s cladding-base metal interface in Section 1-2. (75x) b :./.IQhr. 'M.$ ~, 1 ' l* i..% k R. (,.14 g a ,P.R .e 3 (% g. %. - :, c - 4 +:gy %% - *y. M ' q. ,q ? } i > l,% 3W .d 4 pq 4 m $ b 9 Y k ? h b k,1hhf,,.. t g.Yk .3 s f k' 1 %gfygih# t .h k h An otched view of the cracking at the cladding-base metal interface in Section 1-2. (100x, 2% Nital Etch)

o. I 'i , ~m,s(n~n. +.< h r.R.1,. a:. v.u. %. a... <. l ?f. i &.pv. s a 4 e.. c d.+ : . tu.. y... gmlh$; f. :&f, M,x.1 { yp c; a..N H $ l:,;e. p sv,. 8.. - y (. y* l y? . :. s. wn t M W tM $* % '+ 4 4 D M i ?j . + g r.,.9,.Q.,3.g M.pp 1:k..'r.h,D.j.;#i.:; -i I yh. L'h. W #ar,p 4.'D'#n.., 3,, ( a.r

g;
r-r t h ' W h'4

.i d 7 ' 14:$.,- 1. p _ d. a f*e,,$;T..u[, 5,f.s pw:hkl; F Y?'.. o - ~1 -r- >bdM.:z$m&: ..s j % lb '. h ' RW /.,S?}Mh.,m'.N h..S 7s 1 . y. .a m ; A^ n "[' ' ' I lNir h." ' &';., ' '-y e ,j .?, L .a m...:.s e.',si.*t.. g,.QM h. y., -- Q u.- v . A. w, N. o, o m . v{. ui , d,. j i , w%.e., s. -.s p ; g s a [j'.y;}, q ..{ ?.? .;3 a. -i p Y. j p + crack initiation in Section 1-1. (20x, 10% oxalic acid: Electrolytic Etch) t .o 1 v..,. o. .j.. ,, d, ' ',? ' t.'... : > _. < v'. s.v.,.. %.s,- ,d sr

~\\

t 's o . ' e 1. - t: 4... 4 4. M. s. t s. i ~ ::*:.ve, i. b, '.,,,r. u' p;',;j{ y'.L.j.).(. k'y;J t ';.l,j.,y v... _., >. .e .R .,' }t.. (. j y ', a,,,s. r, .,a. ...,, 1 u.. s;.4 .n ?A'!; " u p,<*

. '} \\.\\ %,,.

1>.s.. y.. ..s. c..

.,l *

.. t, ;;.l,.. ;.. \\ a g. cr. )i n.4'! - -..:. a' 'n. J,; f. 71, 3- .b.; 3 b.. f.*. .t ~ iJ, A,1.,g. s.- . j; < . u. c...; u. r.,,.%q,. ..;.j.., e t i;*

  • n.

'*.'p :. ' f:.. *.,?. n

  • i'tl~, o..'s.o..,. m, > r...

a6* s . U.. - ~.'

.r

= 3.p.+,, h, S h ? . ' qi- 't 3. -.. t i' e '3.,~ t,,, - ' >g. 't ' 9*, ; e s.; J... mm i '.' o ; ;';;s,. 1.s.. g

  • $i. R.:
  • k,,, l,l, L.:' f,0).$,,'.y 3l,jgll1.
34. ; O ff..i,',A f ;, z'.' /,'.l *. ',
  • l

'4. i r . i i

n. r h 4 C., '

i 'V

  • %l.~:. g 'es;

..m(,-{?6-j,1.., 4 ,e 'ar n e 4. ,k. YJ 4- ) g.,.%f. h... ;k.,.,...y.a. a gw:. r s. .O Q(.h,c,' k,h... . s. r .f..'h k hE N h

b

'.Y.,4lly"ki,} k. Q> h; i1 "[ m4: f

.J; g- _

3xw.y C3g m x-l k:. w.. %, M f Cracking at the cladding-base metal-interface in Section 1-1. (75x, 10% oxalic acid: Electrolytic Etch)

~ e ~' :1,~j i i g 7~I i . g g l A L n 1 1.. {-i An etched view of Section 1-1 showing crack propagation into bas m Note oxidation of crack in base metal. (2% Nital l l ?^ d.~5$;;,, y w .g z 9) I

3;iM.' /,

\\f 7 A.f., 'C ' 5Xl ) f, ' k $P The heat affected zone microstructure and corrosion of the base metal at the sample 1-1 fusion line. (200x, 2% Nital Etch)

\\ l( o ( i i 4 i I i j 5, .... - ~ + lA. /p - 1 c"' g g j A q g

J r

g l}) 'A 4.' + 7 } /- [ g, d ~ 4 o, = s ,.c l.' c . Q'Q c\\ g. ':.- n j. j gs. g. s f

..L' M [

4.. yY } fh _g... f L.. :. .) ' ~' ~^V Boat sample 2. Note the heavy surface grinding marks and smeared metal. 1 J

. ;. % r.).e :

N,. ~;. p_*%4 [ C' ' Mf..,--, 1 %s t g y V -N. ', / , '.b -h-Q'" $'M b,t% >.

  • h %'M. k 4

~ 9,gM,?@7.g i S N,";i &'f&!Y.$:f'$$,$:* v-l 4$ 0 b /[, '.,[. Kf l.q,,b $~,' { f,4 .. f... ~- i 1)' ' ! ' ffifI,Y '

  • * /,%l ff f

y h',>'"'

&;lf' L d%

x se + ' <dh M,jy{ lf,}%.D, l p, . = '.. Ybbkl b ti t Incipient interdendritic attack near tre surface of boat sample 2. (225x, Unetched) l {

) e o ~ 1 l 4 ~ g .m r g

  • [

L

i:;9l.

n :al , /, e <p)y',c';%A k'd'..' W, . 6,2 f u w,.. w n s. .,,,,,:[f,; e ;e,yathhk Y *', i,' t. n >1l p -( / r , %ksyn.g_u .[YM q[g 3.' A cold-worked region near the surface of Section 2B-2. Note crack initiation "ron. che cold-worked layer. (500x, 10% oxalic acid: Electrolytic Etch) l k:.g-Q. - ' N.', A t g, - %l., - . \\. g h.'\\\\ v.J s .r, en s g. . m' Q y M. w w 8 :. fy x. s> s - & (.. ' 1 4 ' '..,) ':6' s s'Q.6.N V' e ? ,+~~\\ Q .r,' .r s k,- -, f.Q m ~) -$.:. e's _W: 'Q,' " ' )', t Interdendritic attack initiating adjacent to a cold-worked i l region in Section 2B-1. (500x, 10% oxalic acid: Electrolytic I Etch)

O .f '. ' ~ ~ ~ ' ' (~j -. 'l %d. ' ~ y s ~. ,r Y [- ~ .n [: t, .? ' ;n e :- V , Af .n . r s,. A. y - )?{'[ ~ l l '~ "?N l 9, / " *E[ 'A.,g [-

j. [N,y =

.!'j.((,f.(. W( M. > @. .?' %,; '$

  • 4

+ 3 Macroscopic view of Section 3B-1. The surface crack in this sample was partially ground before sample removal. Note the scallop at the base metal interface as a result of the SMAW process. (10% oxalic acia: Electrolytic Etch) -g.i 3 _ +4%. JC-k ,' /. ._ 49 7 1 '. g ra,> j,,Ih,.'# M' J e

y.

f g.: e '. ;.Q b . ;7,.A } l.if_f=wmm;kW a .., y 4 4,. y.-g. '

p

., + \\ ,,$.e.g[*k - 'k ?. @y- {- Mj.n M, AN'l y e, J y :- s .;g h . f J 'f f hgDfd.'l0 k$fj Mbid$l-b Crack propagation at the surface of the ground out portion of sample 3B-1. (20x, 10% oxalic acid: Electrolytic Etch)

c s. o A

4 ry : _ _r.n y,,

r n.; vn... ' I,*r v.1 ',, n. e f .Q. g t ~ ,y-. v.%. p. Ah ha. '~ l %n.-

v,: q,. g..m. a.. :

.>. ~.. ~ . ?,yg . b , <., gq, a ;..... g4. ;: y,, ' x, y

g,,

.yk[ u.b,.N;. &p:, ; l- .,.cn(,...h.;7.,e .c.. ;q. '.h_; ;., ;.i! ~

b
.:. tr

..;Q. g g,.9 9y

{yg' z.

., n:'.1.;jp...~ c e.:..p. n..e g.. /;(i,'. { .' 's \\ ..s g.m...a:,Lw: gs:p6? 9: .8

. w.e

.x v .h ..C- [ '. d \\ l-

d. '

A closer view of the cracks at the surface of the ground region in Section 3B-1. (75x, 10% oxalic acid: Electrolytic Etch) kk v t A 4 M M. 1h -6 s l/'[' Y . ::. ge3N 97 s [k:k.\\,h. M MiM% ; ,fl3S 4 !N i{: . s 'M..ylg jl. ( %..iN/Akd%g208 1, *- . n) K .r , +. m,g ), e.n. w ?W. a ry.h,'.f.. . 'Mllf$[Q.!,';t.:,;9,;ypp* rn .Q,f ;y',. i @,. - wue.q.,. f.;, q,5., ;, 7

f.,.

g.3;..p...,3.e,:j,2:,,. g: ,. (- . ;,s :, 3;; - y~., ,, sy .a hit!HQ q > c . ;.&jg} yl f.h:f.., ' NS k '. s.s,e. y c 1 ;, c s. ~

f%h ';

i.. s... ,y 4 t .g-7 .s .-8 Cladding crack propagation near the base metal interface in Section 3B-1. (75x, 10% oxalic acid: Electrolytic Etch) )

v / 0 e n,... M t g% g. ,) p,,,g

  • ~'-

L, ~f - / v. ~~f. t j .t ,~ s , L. f _, ;;. j*. ;9:h ( $4+ .+ Y ) p,, V ;,dY{1(g.f @gg-M$m[d@ D mt"- &s l 1 (. c. {

' k - )/ '.. e i g ' gy ' l3..@ ; <f.l!.

ee i 04 's i 'p - l ,..f,.;.m.,r;. ,? 9 3.r. O';j g ';;'N y. i.;] Q y,;;;,;Q.,.,pj,.. c; v ~ s j -~ L ~ e.3. - g <.;,: 1 ,.s -t s...p,,. . j., ~r .r 4 - k ,e 'J l .I , -" I$ (N7.$f D.'s i Y< $,h.'I'M [9"": dGi-M i. i i e l crack terminations at the fusion line on Section 3B-1. (2% I Nital Etch, 100x magnification in left photo, 200x magnification in right photo) L _ = _ _ . c_ l c<, L f gdStw 1 l ) V~ ~ = -. >3 t t ..k )... ~ } ? ,q )k .p j' . h ^ The unaffected base metal microstructure in sample 3. (2% t Nital Etch, 200x)

e .c .n. ,;. Q. . h ;}; g y. .J l g .~ ' 4 a ?",,T 4 ' ].,.'.- ,4 i j' l lt ,. y - ; y;..i i' l + %.9)_3 ~[.

  • / }

-e. w tp , & wb ) s. [ f. J- + 7 f ~: r .8 j , f' * .j.. ( k{ i E g \\ ... r: o q l

} $ $*fpf ' '

,I i Boat Sample 4 - Removed from a crack free area. I l l , go < i f *'. Y 'Y ' i /

.,..yi
__

s ~- -- s. s' g s or ') ? - f ". < t s .p sg y 3, s v h [ ~Yh. i F,i g74,41 e

y. -

O y-f) N 2 The HAZ microstructure in Eection +1. (200x, 2% Nital Etch) e d

= 5 %, we m c.,.e.fNif 9hf 37Q?'nyY.d. '. b Xhi.y \\W?.]. .p.. s. y. o.,.,,.. .o , c,.., ,,c (,

  • e r C [ }9j,.W'WE'.w\\, ),;'. wq 'c# ;' '<:. Y. p ' } l ?.,'

.v. .Nt 1 .o 3. z p-w pu, u, N. g'.c.,,.&, t. n. Tsl

  • E f 't')

'[ *5' 1l~ ! '-{'l

^ 'Y ' '.

',f.* ? ' ' _no,; <-&z. S,. lvt. J , ' ll? ' ~;' 6%.T ". W y .35.,.,. c p :'*+5 ' v,- v' [,-

f
l f,. Ac. e{

%y ' f mN . ~ - i s Y' i% f ^L)p./. $:,[.; $,.5.i'5. p 3.r- - IW 'C', i+ " 7 y.5 .{ $d;.- E f, N.L. 5 " #,#. "I_ ~, ~, '. ,~ , + AI MD25..f, [f E '~ 6 . k.'Oh. s.$$.,. AQh.h!N. M..$,. ik. c.; ~. .['I - 3 . r e. a '. i,# ' , '., ' \\ ' hi. - 7 ap. -. ,M0 /- q s ., ! )' ', 3.* '. - p, - *...< ~ p,.., T .) ~ g, ,, s -'.. c 'J.D. 3 ? ~,d b:..;.s.". tw " p ~.,,- ,[, e '..,, p. t h e cladding.ticrostructure in Section 4B-1. (150x, 10% oxalic acid: Electrolytic Etch) s 1 3 E[' .- l ~ ~ 'W-l (A s i).... ff ', ww) m

g Qy ',

l sN d ,y < ; [ l ^, h U.' g i b .f v h ,T ) l [ 3 s q e_ 0 o-Se base metal microstructure in Section 4B-1. (200x, 21 Nital Etch) I } L i =

}}
Retrieved from "https://kanterella.com/w/index.php?title=ML20034C659&oldid=4582885"