ML031110351
| ML031110351 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/18/2002 |
| From: | Bass B, Williams P - No Known Affiliation |
| To: | Matthew Kirk, Robert Tregoning Office of Nuclear Regulatory Research |
| References | |
| FOIA/PA-2003-0018 | |
| Download: ML031110351 (10) | |
Text
MEMO DATE:
18 October 2002 TO:
M. T. Kirk and Robert Tregoning FROM:
P. T. Williams and B. R. Bass
SUBJECT:
Status Report on Davis-Besse Analyses The attached Figs. 1-6 provide a summary of the Davis-Besse analyses performed to date under the new Task 9 of JCN Y6533. In Fig. 1, the cladding properties used in the current study are presented:
(a) true stress versus true strain and (b) thermal expansion coefficient versus temperature. The remaining figures address a specific sub-task described in the workscope for Task 9.
Sub-task 9.1D requires an estimate for crack driving forces as a function of flaw size and applied membrane stress in cladding. Table I shows the Case Matrix developed for this subtask.
Figure 2 depicts the first step carried out in preparation for the J-integral analyses, i.e., calculation of an updated estimate of the exposed cladding "footprint" based on the recent "dental mold" cast from the D-B cavity. That footprint area was estimated to be 28.23 in2. Comparisons of the latest "footprint" statistics with previous ORNL interpretations are given in the table of Fig. 2(b). The newly calculated "footprint" area was used to define a burst disk having the same cross-sectional area.
Table 2 presents ductile tearing data for three-wire series-arc stainless steel weld overlay cladding published in NUREG/CR-5511 [1]. The ductile-tearing data presented in Table 2 are plotted as a function of temperature in Fig. 3.
Figure 4 presents six finite-element models developed so far for this phase of the analysis.
Surface-breaking flaws were centrally located in each burst disk with the three relative flaw depths: alt = 0.5, 0.25, and 0.05. The models for two flaw lengths of 2.0 inches (50.8 mm) and 1.0 inch (25.4 mm) have been developed to date. The remaining three models in the case matrix of Table I will apply a flaw length of 3/8 in. (9.525 mm)
Each models were loaded with an increasing lateral pressure. The resulting J-integral loading paths for these six models are shown in Fig. 5. Figure 5 also presents a value of J1, for a temperature of 318.3 'C (605 'F) estimated by extrapolating from the data in Fig. 3a using a 4th order polynomial curve-fit.
Figure 6 compares the critical pressures (determined from the results shown in Fig. 5) for two potential failure modes of the burst-disk models. The ductile-tearing critical pressure is calculated from the point at which the load path for each flaw crosses the JI, line in Fig. 5 and represents the pressure at which stable ductile tearing initiates. The plastic-collapse critical pressure was estimated from the load at which each model began to approach a numerical instability in the analysis. From the curves in Fig. 6, the controlling failure mode for the two larger flaws in the current study was ductile tearing. The shallow flaw (alt = 0.05) was close to the J,] line when it began to fail by plastic collapse. Decreasing the flaw length produces a slight increase in the ductile-tearing critical pressure.
1
Estimates of the applied tearing modulus shown in Fig. 3b were calculated using the data (see Fig. 5) from the three flaws with 2L = 2.0 in. at a pressure of 6.4 MPa (0.928 ksi) and the three flaws with 2L = 1.0 in. at a pressure of 8.2 MPa (1.19 ksi). As indicated by the comparison in Fig. 3b, this estimate of the applied tearing modulus indicates a stable ductile tearing for the larger flaws, thus implying stable tearing for the smaller flaws as well.
References
[1] F. M. Haggag, W. R. Corwin, and R. K. Nanstad, Irradiation Effects on Strength and Toughness of Three-Wire Series-Arc Stainless Steel Weld Overlay Cladding, NUREG/CR-55 11 (ORNUJIM-1 1439), Oak Ridge National Laboratory, February 1990.
2
Table 1. Case Matrix for Task 9.1D Number -
(inches) inches)
-,)
(
-)
9.ID1 0.1250 2
0.50 16 9.1D2 0.0625 2
0.25 32 9.1D3 0.0125 2
0.05 160 9.1D4 0.1250 1
0.50 8
9.1D5 0.0625 1
0.25 16 9.1D6 0.0125 1
0.05 80 9.1D7 0.1250 0.375 0.50 3
9.1D8 0.0625 0.375 0.25 6
9.1D9 0.0125 0.375 0.05 30 Table 2. Ductile Tearing Data Extracted from Table 13 of NUREG/CR-5511.
A13G H2 A1 56a A1 3D Al OG Al OE H5 H3 A1 3Fa H6 H4 A15D A13C H1
-75 117
-75 137 20 165 20 134 20 171 120 128 120 119 120 120 64 49 270 209 176 246 229 232 359 240 231 267 170 192 120 200 200 288 288 288 159 90 111 77 66 82 Irradiated Specimens A15F
-75 78 40 A1 5G
-75 56 36 Al 3A 30 144 177 A15C 50 124 146 Al OF 120 94 175 A1 5A 288 25 191 a Specimen was not side-grooved, while all other specimens in table were side-grooved 20%.
3
80 70 500 70 60 a.
4 400 2 I
fl~lM...IN 50 3=94 36 (ksi) 300 t' 40 4-30
- 200 t 20 E = 25570.85 ksi
-- 100
. V= 0.295 10 lo 0
- - --- i 0 0
0.05 0.1 0.15 0.2 (a)
Total Strain.
09'2712002 K3 ptw 1.5105 r-L 1.4104 L
V 1.3 10'5 0
a 1.110-l II i,
0 500 1000 1500 2000 2500 3000 0912712002 K2 ptw (b)
Temperature (°F)
Fig. 1. Cladding properties used in the current study: (a) true stress vs true strain and (b) thermal expansion coefficient.
4
I I
0
'0, 0
Footprint 9/2312002 Area = 28.23 in.!
R31.712 (a)
F5
' V
' s,
.C' Desm 1
D n S,<
ScdaFmx SAm Puim Aw.UVFa4mt
- Pind, Mw1~dS*,,'
FrRmaPw~dDwwx.b-B>-
As-Fo.nd Foopnt 2
35.36 30 36 164122 401194 9B89 9699 33 -11716 75 26 19741
<09004,.-A351>
<04351.0.9004>
AdjusstedFootpnn 0.25,m 40.06 31 78 16 4301
-01255 1329 02 11031 81 -141.35 99 00 245 71
<08943,-04476>
<04476.0.8943>
for Boundmng Cadcdtuon AsFotmd Footprs 1
28.23 24.55 15.332
-0 8 95 56 670S 63
-50 52 54 01 113 07 10 558 0 8301 1-.300.3581 Foolpnmn ceaord u In global cooedttates.
Global coodase system has at zae aligned wtl the eucal] cetelme of lhe vnseL The xny plane of the global coordinate system I a leetontal plate (b) wlt the at s along the hoe heoween the ceatlmes of Nozzles 3 nd II Fig. 2. Latest footprint estimated from "dental mold".
5
Temperature (0F) 0 200 180 -
400 600 S
a 160 E
140
-3 120-100 -
80 Data from Table 13 (unirradiated)
NUREGICR-5511 i
i
_q i
-.1 a
a 0.96 0.88 x
-U, 0.8 0.72 v
0.64 *.).-
0.56 0.48 0.4 I
0 60
-100 0
100 200 300 400 1 0O4/2002 K2 ptw (a)
Temperature (0C)
Temperature (OF) 0 200 400 600 400 0
350 I-Data from Table 13 (unirradiated)
NUREGICR-5511 n
-o
'S
.0 0a a,
I.-
300 1 250 200.
/
Applied Tearing Modulus at 6.4 MPa (0.928 ksi) 2L = 50.8 mm (2.0 inches) t = 6.35 mm (0.25 inches)
Applied Tearing Modulus--
_t._ MPa 11.19 k.i.
150 100 I-
)I8 50.
2L = 25.4 mm (1.0 Inches) t = 6.35 mm (0.25 inches) 0 _
-100 0
100 200 300 1011712002.K3 ptv 400 (b)
Temperature ( 0C)
Fig. 3. Ductile tearing data for three-wire series stainless steel weld overlay cladding from Table 13 of NUREG/CR-5511: (a) J1, data from unirradiated specimens and (b) tearing modulus data from unirradiated specimens 6
Fixed-Grip Boundary on Outer Edge (a)
T-o,-
Fixed-Grip Boundary on Outer Edge 2U.32
.35 mm (0l 2 in)
IY~~ 1 1s)n
-,CI616 an mmL2"H76 In I (b) r Art. - IS.2'64 nmm' (2n 4 ')
Fixed-Grip Boundary on Outer Edgc iL'.
- li M.5M 02.
?
11 76JUiS w 2.09076 L.
(c)
/
Am. - I&I-26.4.
' (28:S i n.)
Fig. 4. Finite-element models used in calculating applied J-integrals produced by pressure loading of burst disk: (a) Model 9.1D1 (alt = 0.5, 2L/a = 16) (b) Model 9.1D2 (alt = 0.25, 2L/a = 32), and (c) Model 9.1D3 (alt = 0.05, 2L/a = 160) (Task 9.1D) 7
ihbed-Crip Bnundsry on Outer Edge fl.7LtU~--
ct-l' An5 I Kuha'f2n..)
L.1 5
, A I-)
B.
2.7 Ind Gus" 1 -
'.1i~
A 2;2 an*
(d)
'RV Fxed-Gnp BEundary an Outer Edge 112 AmL" I.A (e)
Fixed-Grip boundarry on Oater Edge (II Fig. 4. (continued) Finite-element models used in calculating applied J-integrals produced by pressure loading of burst disk: (d) Model 9.1D4 (alt = 0.5, 2LIa = 8) (e) Model 9.1DS (alt = 0.25, 2L/a = 16), and (f) Model 9.1D6 (alt = 0.05, 2L/a = 80) (Task 9.1D) 8
Pressure (ksi) 1 2
3 4
5 6
7 8
600 -
500 E
0) 0 i
400 300 200 100 n
3.2 2.8 IN 2.4 2
1.6 X
am 1.2 0.8 0.4 n
a = 0.3175 mm 2L/a=160-*
a/=0.05
,..~-- l V
'~
I EI 0
10 20 30 40 50 60 Pressure (MPa) 10Q17/2002.K1 ptw Fig. 5. J-integral driving forces from three finite-element models as a function of applied pressure.
9
60 t = 6.35 mm (0.25 inches) 8
.50 -
7 IL) 40
\\
~
aPlastic Collapse 6 a LO 40 L-A 5
U) 30 2L 2.0 in.
4 ir 20
__Set-point pressure peratinXpre re
-T2 10Ductile Tearin.
0 0
0.1 0.2 0.3 0.4 0.5 0.6 alt 10/18/2002.K4 ptw Fig. 6. Comparison of critical pressures for two failure modes as a function of relative flaw depth. Two flaw lengths ( 2 in. (50.8 mm) and 1 in. (25.4 mm)) were used in the current analysis.
10