ML033350358
| ML033350358 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 11/30/2003 |
| From: | Hour K, Hyres J BWXT Services |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 1140-025-02-24 31-5029337-02 | |
| Download: ML033350358 (55) | |
Text
BWXT SERVICES, INC.
1 140-025-02-24 172 BWXT SERVICES, INC.
1140-025-02-24 172 Interdendritic cracking Fracture surface is heavily oxidized Ductile tearing corner from crack opening up in lab
\\
CRDM nozzle 3 bore I.D. surface Figure 7.2.4.2: Low magnification SEM mosaic of the fracture surface after opening-up the axial crack. BSE 6.7X Figure 7.2.4.3: Higher magnification of the left section in Figure 7.2.4.2.
Cracking is interdendritic exposing a well-defined columnar solidification structure.
BWXT SERVICES, INC.
1 140-025-02-24 173 Figure 7.2.4.4: Higher magnification of the middle section in Figure 7.2.4.2. The fracture surface is heavily oxidized; the fracture mode is indeterminate.
Figure 7.2.4.5: Higher magnification of the right section in Figure 7.2.4.2.
Cracking to the left side of ductile tearing (lab fracture) is interdendritic.
BWXT SERVICES, INC.
1 140-025-02-24 174 BSE 6.7X 132x A-t Specimen: Oak se A2A6SAC2 EDS of ae 1, uirge 11 1326M4.
Uicwted, tC kV EL-ret: C, O, Si, Cr. M, Fe, M. Zr' Z
- onrnied uskg 30 kv. P - pc& ovt Leps Zi aid mray, or rra rot. be pesent ao.
F S
t0 anwrO.035 kV SS1 at ID U kMa Vert=400 0 Wndov 0.005 40.955= 36673S ant EDS results for area 1.
Figure 7.2.4.6: BSE micrograph mosaic of the open crack surface (same area as Figure 7.2.4.2) along with EDS results for three areas of the fracture surface. The dark area in the BSE image indicates the fracture surface was covered by a thick oxide layer. The light area (right side) indicates a fresh fracture surface due to crack opening-up (i.e., less oxide on surface). For area 1, the primary elements included carbon, oxygen, silicon, chromium, manganese, iron, nickel, and zirconium.
BWXT SERVICES, INC.
1140-025-02-24 175 III 1t3 NA-2 Specten: Davis Besm A2ASA2C2 EDS of eree 2, Lmage It 1326_MA.
LUcoated, 10 kV.
Eenents: C, 0, Al, Si, Ti, Cr, Mn', FL, Ni, 7r, Sn Mr*' -L ke!y. Cverpped by Cr/Fe. Ail'e relatfre to Cr KBeta suggcsts its presence.
C+/-ar=0.04S keV 705cnt IDLIckl
/ert=20000 Wlr'4adwiO.0S-40.9S5=
1141267cnt EDS results for area 2.
Figure 7.2.4.6 (cont.): For area 2, the primary elements included carbon, oxygen, silicon, chromium, manganese, iron, nickel, and zirconium. Similar results were obtained for area 3, except area 3 also contained niobium and calcium.
BWXT SERVICES, INC.
1 140-025-02-24 176 BWXT SERVICES, INC.
1140-025-02-24 176 P
o N
I
-'I Figure 7.3.1.1: Macro photograph of metallographic sample A2A6A2B2. The mounted surface is through the J-groove weld at -450. Refer to Figures 5.6 and 5.7 for the sample orientation.
cG'
BWXT SERVICES, INC.
1140-025-02-24 177 BWXT,
SEVCS IN.14-050-4 177.1 P1 i
12X Figure 7.3.1.2: Slightly higher magnification photograph of metallographic mount A2A6A2B2.
BWXT SERVICES, INC.
1 140-025-02-24 178 BWXT SERVICES, INC.
1140-025-02-24 178 Ii Id
.f Etched It I
- i.
Y.
Cladding-La J-groove weld 48X
/.
-V A
iK.
(
I.
*1 4
-A I'
Etched 1 OOX Figure 7.3.1.3: Intergranular or interdendritic cracking initiating at the cladding surface and extending into the J-groove weld. Note that the micrographs shown are mirror image of the photo in Figure 7.3.1.2.
Intergranular attack (IGA) is also evident on the exposed surface of J-groove weld and cladding (surface exposed to oxygenated boric acid). This cracking is likely initiated by IGA.
BWXT SERVICES, INC.
1140-025-02-24 179 4
g II a
J 4
Ii' 3..
t
- d.
-a 4**.
r
-S
-
4
'a a,,..
L
-
- *
a
- a a*
V F /
a
. S.,
i*-.*.I,.--
a I j
- .a*
JJ.4'/
a
- ,J 4'
-a.
4 S -
- A t
Y.
- A...
,...r-(*
I,.
' *' *4,*
.1 A
p*..
4-,
/
I.
Ž:¶ c"
f
.3
.1-.
2
-
- ,
.,
*
r
'p Etched 375X Figure 7.3.1.4: Higher magnification micrograph showing intergranular or interdendritic cracking initiating at the cladding surface and extending into the J-groove weld.
BWXT SERVICES, INC.
1 140-025-02-24 180 BWXT SERVICES, INC.
1140-025-02-24 180 I
Figure 7.3.1.5: Low magnification micrographs showing shallow circumferential cracking in the J-groove weld.
BWXT SERVICES, INC.
1140-025-02-24 181 et t.
t S
XT Etched 170X Figure 7.3.1.6: Micrograph showing the shallow circumferential cracks in the J-groove weld. The cracking is intergranular or interdendritic, with a maximum depth of approximately 0.019" below the surface. The two wider crack regions just below the surface may have been dendrites or grains encircled by cracks that subsequently dropped out during sample preparation.
BWXT SERVICES, INC.
1140-025-02-24 182 BWXT SERVICES, INC.
1140-025-02-24 182
.. ~~~~~
~~*
- J 7:
i W
-~~~~.
4'
.,^.- >
r
- f.
A
,3 I-,
Etched 375X Fi guire 7.317 Micrographs showing crack tips of the circumferential cracking in the J -groove weld.
BWXT SERVICES, INC.
1140-025-02-24 183
.S...............'_
Ad... t~
w 1
Etched 375X Figure 7.3.1.8: Typical J-groove weld microstructure.
BWXT SERVICES, INC.
1140-025 02-24 184 BWXT SERVICES, INC.
1140-025-02-24 184 4X Figure 7.3.2.1: Macro photograph of metallographic mount A2A6A2D2. The mounted surface is through the J-groove weld at -300. Refer to Figures 5.6 and 5.9 for the sample location.
CS(Dd1.
BWXT SERVICES, INC.
1140-025-02-24 185
.~ ~
~
~~I
.Li Etched ID0OX N
Etched 1 OOX
- ~ ~
~ ~ ~ ~ ~ ~ ~ ~ ~
-~
- ,','~~~-
' '..ae; w
- j.
i appr;x'ate'y; I
- ~ a.
--C' l;A Etched 190X Figure 7.3.2.2: Micrograph showing the circumferential intergranular/interdendritic cracks in the J -groove weld. The maximum cracking depth is approximately 0.018" below the surface. The cavity just below the surface may be due to dendrites or grains encircled by the cracks that dropped out during sample grinding and polishing.
BWXT SERVICES, INC.
1140-025-02-24 186 Si - -
I J-grooveK weld
~~~~~~
.,L J
. Cladding *Y
-1 Etched 48X I
T Etched
.~~ ~
'-I
.1 X, I '....
I.
I
. -1 10OX Figure 7.3.2.3: Micrographs showing the intergranular or interdendritic cracking between the J-groove weld and cladding interface. The micrographs shown here are mirror of the photo in Figure7.3.2.1. Intergranular attack (IGA) is also evident on the exposed surface of J-groove weld and cladding (surface exposed to oxygenated boric acid). This cracking was likely initiated by IGA.
BWXT SERVICES, INC.
1140-025-02-24 187
.1
- h A
-Y IS
'-.4
- S 5
. j
.s I
a I
`
I T:
Etched 375X Figure 7.3.2.4: ntergranular attack (IGA) on the J-groove weld surface exposed to oxygenated boric acid.
BWXT SERVICES, INC.
1140-025-02-24 188 f - Crackin nitatd.,
fromi the exposed 4~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4 tS~~~~~~r-
'~~){
~-'i)/t't J-groove,,-.,..-.
Circumferentil cracking, L~~61'u er--9o-s,?ie
,At
, jtX,,...:,'
Figure 7.3.3.1: Low magnification BSE micrograph of sample A2A6A2D2 showing the cracking in the exposed cladding surface and the axial cracking in the J-groove weld surface exposed to RCS. The EDS spectrum collected from area I is presented in Figure 7.3.3.2.
BWXT SERVICES, INC.
1140-025-02-24 189 111493-i Speceren:
ats Besse
~A 6A'D' EDS of aea, Fnagc 11 14 3 ( jA)
Carbon Coated, 20 1-N.
D~nwntsi See Q lanhtati=n Ccbon mt kcxdcd (coatcd).
(*t
..'t tr SE A.. S,.I S.WX_
.Ss s
- e.
- 1.._dl,.
t-zsswt*.cv vs ~v nn U,
L..._I.I i
S~
.sa
'4.1: s.".
S 4tS.
.1
.Sf t
n Nl e t *y....
- . _ a...n si-r 5
10 sw -0.06S keV 0 M ID =U k r=5464
%:J;dos n0.00S 40.9S5= 440070cn_
Figure 7.3.3.2: The EDS spectrum for area 1 in Figure 7.3.3.1. The semi-quantitative results from this area, which was located within the J-groove weld, were consistent with Alloy 182 weld metal.
BWXT SERVICES, INC.
1140-025-02-24 190
~~~...
.7~~~~~".i "i':
I
.17
~
.ti BSE OOX Figure 7.3.3.3: Low magnification BSE micrograph showing the cracking that initiated from the exposed cladding surface (left side of figure). The maximum crack depth is approximately 0.055" below the cladding surface.
BWXT SERVICES, INC.
1140-025-02-24 191 r
Figure 7.3.3.4: SE micrographs of the circumferential cracking in the J -groove weld. The maximum circumferential cracking depth is approximately 0.032" below the surface. Cracking was interdendritic in nature.
BWXT SERVICES, INC.
1140-025-02-24 192 Figure 7.3.4.1: Macro photograph of the opened-up circumferential cracking in the J -
groove weld at -30°. The underside surface of the J -groove weld (in contact with RCS) is shown. Refer to Figures 5.6 and 5.8 for the sample location. The rectangular sample (A2A6A2C2) is secured to the round SEM stub with black carbon tape.
BWXT SERVICES, INC.
1 140-025-02-24 193 BWXT SERVICES, INC.
1140-025-02-24 193
,s DO`
Of I' I
A4
- c "
I SE 200X Figure 7.3.4.2: SE micrographs showing the shallow circumferential cracking in the J-groove weld. Cracking was interdendritic.
BWXT SERVICES INC.
1140-025-02-24 194
'.2;,,
"1*
p
-
A
- 4
1.
L'4
- 'r
- .
4.
-4' q,
,
I-.,
..S, '.'
4,'
Figure 8.1.1.1: Macro photograph of sample AlB2. Refer to Figures 5.13 and 5.14 for the sample location. The white box shows area enlarged in Figure 8.1.1.2.
BWXT SERVICES, INC.
1 140-025-02-24 195 BWXT SERVICES, INC.
1140-025-02-24 195 Figure 8.1.1.2: Low magnification micrograph showing horizontal striations aligned with the major axis of the RV head low alloy steel plate (SA-533, Gr. B (mod), Cl. 1). The striations are due to the segregation of carbides, which promote a slightly faster local corrosion rate along the striations. Note that this micrograph is a mirror image of Figure 8.1.1.1.
BWXT SERVICES, INC.
1140-025 02-24 196 Figure 8.1.1.3: Higher magnification micrograph, which indicates a slightly faster local corrosion rate along the striations.
Figure 8.1.1.4: Micrograph showing the typical tempered martensitic microstructure of SA-533, Gr. B (mod), Cl. I low alloy steel plate.
BWXT SERVICES, INC.
1140-025-02-24 197
.j,' t Figure 8.1.2.1: Macro photograph of metallurgical mount Al B4. Refer to Figures 5.13 and 5.14 for the sample location. The white box indicates the area shown at higher magnification in Figure 8.1.2.2.
BWXT SERVICES, INC.
1 140-025-02-24 198 BWXT SERVICES, INC.
1140-025-02-24 198
'' "' 0""'
r ----'-
f V
.f,
' 1. -.-
I '.'%.
' ---W - :-'11
%-I Figure 8.1.2.2: Higher magnification micrograph showing the horizontal striations aligned with the major axis of the RV head low alloy steel plate (SA-533, Gr. B (mod), Cl. 1). However, unlike Figure 8.1.1.3, the striations do not appear to promote a faster corrosion rate locally.
BWXT SERVICES, INC.
1 140-025-02-24 199 BWXT SERVICES, INC.
1140-025-02-24 199 Figure 8.1.2.3: At higher magnification, the local corrosion rate along the striations is increased only very slightly.
Figure 8.1.2.4: Micrograph showing the typical tempered martensitic microstructure of SA-533, Gr. B (mod), Cl. I low alloy steel plate.
BWXT SERVICES, INC.
1 140-025-02-24 200 BWXT SERVICES, INC.
1140-025-02-24 200 Figure 8.1.3.1: Low magnification SE micrographs of cavity wall surface near 900. The surface contains generally round depressions measuring -0.039" or less in diameter.
BWXT SERVICES, INC.
1 140-025-02-24 201 BWXT SERVICES, INC.
1140-025-02-24 201 Figure 8.1.3.2: Higher magnification micrographs of the cavity side wall near 900.
BWXT SERVICES, INC.
1 140-025-02-24 202 BWXT SERVICES, INC.
1140-025-02-24 202 Figure 8.1.3.3: SE micrographs showing corrosion products on cavity side wall near 900.
BWXT SERVICES, INC.
1140-025-02-24 203 p
p p
p p
p p
p p
p p
p p
p p
p p
p Figure 8.2.1.1: Low magnification photographs showing macro etch results.
Arrows indicate corrosion grooves associated with corresponding micro-structural banding. Macro etch was performed on two surfaces of sample Al D2E ground with 400 grit paper. Etchant: 10% nital.
BWXT SERVICES, INC.
1 140-025-02-24 204 BWXT SERVICES, INC.
1140-025-02-24 204 4'
-t 4X Figure 8.2.2.1: Macro photograph of metallurgical mount Al D2B1.
Refer to Figures 5.13, 5.15, and 5.16 for the sample location. The white box indicates the area shown at higher magnification in Figure 8.2.2.2.
BWXT SERVICES, INC.
1 140-025-02-24 205 BWXT SERVICES, INC.
1140-025-02-24 205 Figure 8.2.2.2: Slightly higher magnification micrograph showing the horizontal striations aligned with the major axis of the RV head low alloy steel plate (SA-533, Gr.
B (mod), Cl. 1). Striations appear to be caused by a very slightly faster local corrosion rate. Note that this micrograph is a mirror image of Figure 8.2.2.1.
BWXT SERVICES, INC.
1 140-025-02-24 206 BWXT SERVICES, INC.
1140-025-02-24 206 Figure 8.2.2.3: Higher magnification detail of Figure 8.2.2.2, which suggests a slightly faster local corrosion rate along the striations.
Figure 8.2.2.4: Micrograph showing the typical tempered martensitic microstructure of SA-533, Gr. B (mod), Cl. I low alloy steel plate.
BWXT SERVICES, INC.
1140-025-02-24 207
, % T r
.t-'
-~
4X 4
~~~~~~i
~~~~~~~~~~.-
I, Figure 8.2.3.1: Macro photograph of metallurgical mount Al D2DI. Refer to Figures 5.13, 5.15, and 5.16 forthe sample location. The white box indicates the area shown at higher magnification in Figure 8.2.3.2.
BWXT SERVICES, INC.
1 140-025-02-24 208 BWXT SERVICES, INC.
1140-025-02-24 208 Figure 8.2.3.2: Higher magnification detail of Figure 8.2.3.1 showing the horizontal striations aligned with the major axis of the RV head low alloy steel plate (SA-533, Gr.
B (mod), Cl. 1). Striations appear to be caused by a very slightly faster local corrosion rate.
BWXT SERVICES, INC.
1 140-025-02-24 209 BWXT SERVICES, INC.
1140-025-02-24 209 Figure 8.2.3.3: Higher magnification detail of Figure 8.2.3.2, which suggests a slightly faster local corrosion rate along the striations.
Figure 8.2.3.4: Micrograph showing typical tempered martensitic microstructure of SA-533, Gr. B (mod), Cl. 1 low alloy steel plate.
BWXT SERVICES, INC.
1140-025-02-24 210 BWXT SERVICES, INC.
1140-025-02-24 210 I,~~~~~~~~~~~~~~~~~~~~~~~~~~~~I BSE 1 8X Figure 8.2.4.1: SE (top) and BSE (bottom) micrographs of the cavity wall surface near 270°. The surface contained rounded depressions measuring 0.020" in diameter or less. Orientation of micrographs: lower portion of cavity to the right and upper portion to the right. Nozzle #3 is closer to lower edge of micrograph.
BWXT SERVICES, INC.
1 140-025-02-24 211 BWXT SERVICES, INC.
1140-025-02-24 211
~r ~
' ~.'
E r
it I
Figure 8.2.4.2: SE micrographs of cavity side wall near 270°. These micrographs suggest that larger (-1 mm dia.) shallower depressions are caused by acid boiling and smaller (0.3 mm dia.) deeper depressions are caused by inclusions.
BWXT SERVICES, INC.
1 140-025-02-24 212 BWXT SERVICES, INC.
I 140-025-02-24 212 Figure 8.2.4.3: Higher magnification SE micrograph showing corrosion products on cavity side wall near 2700.
BWXT SERVICES, INC.
1 140-025-02-24 213 BWXT SERVICES, INC.
1140-025-02-24 213 Figure 8.3.1.1: Macro photograph of metallographic mount A2A7D. Refer to Figures 5.1 and 5.11 for the sample location.
BWXT SERVICES, INC.
1140-025-02-24 214 t~~~
i ~.
i
. f.5 Etched 48X Figure 8.3.1.2: Micrograph showing the edge of the exposed cladding in the undercut region. Note: the micrograph is a mirror image of the macrograph in Figure 8.3.1.1.
l I
- ... i
. i
.? *,
I
. i..
II.
I.
Etched 48X Figure 8.3.1.3: Micrograph showing intergranular attack (IGA) and intergranular or interdendritic cracking in the cladding. The maximum depth of the crack tip is approximately 0.047" below the exposed cladding surface.
BWXT SERVICES, INC.
1140-025-02-24 215 i~~~1--~~1
/
- g 7~
.t~~~~
8
.~
.....i Etched 1 OOX
~~t Figure 8.3.1 A: Micrographs showing intergranular attack (IGA) and intergranular or interdendritic cracking on the exposed cladding surface.
BWXT SERVICES, INC.
1140-025-02-24 216 BWXT SERVICES, INC.
1140-025-02-24 216 16 ~
~
~ ~ ~
q~~~
i.-'Etc ed OO i
A& *,
.a t
r e s w >
s 8
e w
f z_
s
\\
z z
v as, r
- of
' 'I; H4-
I -j I.
'.1 II-I I"Y
@-§gw~~~~~~~~~~~~
4 4'
- 4l S ~
~
f
'i Ap
'-'S Etched 375X~
Figure
~~~
8.31.5 Mirga hwn teitraebten h
o lo te (above~~~~~~~~~~~~~~~~~~~~~~.
th4uinln)adtesanessee ldig(eo h
uinln)
BWXT SERVICES, INC.
1 140-025-02-24 217 BWXT SERVICES, INC.
1140-025-02-24 217
'K
1
-L
)
- i 9
I,.K N
I 0
- vk*
j*1 I\\~
.'-\\
i
.'G' Etched 375X S.
F -
r I.
,I
- -.m Figure 8.3.1.6: Micrographs showing typical stainless steel cladding microstructure.
The interdendritic solidification structure is delineated by small pools (or islands) of ferrite in an austenitic matrix.
B N
cr S
RV41.25.2.2 4 'JI E
,I V~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i
- Rer t figu es5 -
an-
BWXT SERVICES, INC.
1 140-025-02-24 219 BWXT SERVICES, INC.
1140-025-02-24 219 I
0 1 1 ' "
. i 1.11 I. -' ;
I Etched 41X Figure 8.3.2.2: Micrograph showing the exposed cladding surface. A slight undercut is evident in the low alloy steel. Note: the micrograph is a mirror image of the macrograph in Figure 8.3.2.1.
BWXT SERVICES, INC.
1 1404025-02-24 220
- .;I
, I..
1t 1
- ~*
4 Etched 1 OOX I
I.
..$
/
)
I
(.'
l
'O r
375X Figure 8.3.2.3: Micrographs showing intergranular attack (IGA) and intergranular or interdendritic cracking. The maximum depth of the crack tip is approximately 0.024" below the exposed cladding surface.
BWXT SERVICES, INC.
1140-025-02-24 221 O;W.
cr
-*.--J-
-v..
ii
'-.
N jI>.
1
4..
1.*
.J
.1
.4.
'0,
,i*..
.4.
'.-:A 3
.
S
.- )
,f Etched IOOX 7-.
0
e.
4 N...
9 I
A.
I.
-
d 4 9
'1 t.
% k.
I 4 J.
A
. I
.9 I
I..
Al e
~~~*
Et.,,
Etched IS j
I
'- -4
. \\
..11
'375X
.4.
.0 Figure 8.3.2.4: Micrographs showing the interface between the low alloy steel (above the fusion line) and the stainless steel cladding (below the fusion line).
BWXT SERVICES, INC.
1140-025-02 24 222 BWXT SERVICES, INC.
1140-025-02-24 222
-I L~~~~.
w~~
~
H i
beX4O j
i f
'}
(
^!rz
- -'.( *-<
l
-s 4-.
\\
- 4\\~~~~~~~~~~~~4 Etched 375X Figure 8.3.2.5: Micrographs showing the typical stainless steel cladding microstructure. The interdendritic solidification structure is delineated by small pools (or islands) of ferrite in an austenitic matrix.
BWXT SERVICES, INC.
1140-025-02-24 223 I-11/4
- ,
Figure 8.3.3.1: Macro photograph of metallographic mount A2A7K.
Refer to Figures 5.1 and 5.11 for the sample location.
BWXT SERVICES, INC.
1140-025-02-24 224 U -!
a ~ ~ ~ ~ ~ ~ ~ ~ ~..-
4..
I Etched 48X Figure 8.3.3.2: Micrograph showing the edge of the exposed cladding in the undercut region. Note: the micrograph is a mirror image of the macrograph in Figure 8.3.3.1.
'.;H~,..~
),;;,'
I'.
A
- ~
~
~ ~ ~ ~ LZ,
-t
- ¢'*
- ~E c
e 48X*.
1 ~
Figure 8.3.3.3: Micrograph showing minor intergranular attack (IGA) in the exposed cladding surface.
BWXT SERVICES, INC.
1140-025-02-24 225 4
S.
100*~.
.I Ie Etched 5'2 I
I 375X Etched Figure 8.3.3.4: Micrographs showing the interface between the low alloy steel (above the fusion line) and the stainless steel cladding (below the fusion line).
BWXT SERVICES, INC.
1 140-025-02-24 226 Figure 8.3.3.5: Micrographs showing the typical stainless steel cladding microstructure. The interdendritic solidification structure is delineated by small pools (or islands) of ferrite in an austenitic matrix.