ML031110232
| ML031110232 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 10/25/2002 |
| From: | Bass B, Williams P Office of Nuclear Regulatory Research |
| To: | Matthew Kirk, Robert Tregoning Office of Nuclear Regulatory Research |
| References | |
| FOIA/PA-2003-0018 | |
| Download: ML031110232 (11) | |
Text
M_E_M_O DATE: 25 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 lateral surface area under load.
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 nine finite-element models developed 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 three flaw lengths of 2.0 inches (50.8 mm), 1.0 inch (25.4 mm), and 3/8 in. (9.525 mm) have been developed.
Each model was loaded with an increasing lateral pressure. The resulting J-integral loading paths for the nine 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 J1, 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 (aft = 0.05) was close to the J1, line when it began to fail by plastic collapse.
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), three flaws l
with 2L = 1.0 in. at a pressure of 8.2 MPa (1.19 ksi), and three flaws with 2L = 0.375 in. at a pressure of 14.93 MPa (2.165 ksi). As indicated by the comparison in Fig. 3b, these estimates of the applied tearing modulus indicate a stable ductile tearing for the larger flaws, thus implying stable tearing for smaller flaws as well.
References
[I] F. M. Haggag, W. R. Corwin, and R. K. Nanstad, IrradiationEffects on Strength and Toughness of Three-Wire Series-Arc Stainless Steel Weld Overlay Cladding, NUREG/CR-55 11 (ORNLITM-1 1439), Oak Ridge National Laboratory, February 1990.
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Table 1. Case Matrix for Task 9.1D Ki, Number, .', w'; .2 (inches) t(i'nches<)>i> (-
g'd< < W-(_-)'$Y; 9.1D1 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.
'76 Specimen mm+,STearling"ao ec i 8 >z i ¢ £e Unirradiated Specimens A13G -75 117 64 H2 -75 137 49 A15Ba 20 165 270 A13D 20 134 209 Al OG 20 171 176 Al OE 120 128 246 H5 120 119 229 H3 120 120 232 A13Fa 120 159 359 H6 200 90 240 H4 200 111 231 A15D 288 77 267 A13C 288 66 170 H1 288 82 192 Irradiated Specimens Al5F -75 78 40 A15G -75 56 36 A13A 30 144 177 A15C 50 124 146 AlOF 120 94 175 Al5A 288 25 191 aSpecimen was not side-grooved, while all other specimens in table were side-grooved 20%.
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80 500 70 60 IL 400 E
.n 50 I-U) 300 V) 40 (a
A> 30 V) 200 M 100 20
,1 00 10 0 . --- -- _. . O 0 0.05 0.1 0.15 0.2 TrAl I*.-it 09'2712002.K3 ptw (a) lodi I-)
O;UdIln 1.5 10 -
U- 1.4 10' 5 --
0 CD 0
CD 1.3 10 5 -
0 cn
- 0. 1.2 10 x
LU I- 1.1 10 1 10-5 0 500 1000 1500 2000 2500 3000 0 09127/2002 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.
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3 Footprint 9/23/2002 il Area = 28.23 in.'1 ' R31.71I ICR.
(a)
.3o2 do W u aa Mo~~ ~ir dia fi tEi Exe Esi Ze __ _ _ _ __ _ _ _ __ _ _ _
c c Fmclor im mcrit JmFo a '3 A odftCM=Wd Priniitpal MOvMU ,, epeI D SD s.~ Cm~(a)
' ) Cm')~(m Ai Found Footpnnt I 35.36 30.36 164122 401194 98S9 969933 -117 16 7526 19741 <09004,.04351> <04351,09004>
AdjustedFootpmnt 025m. 4006 3178 164301 401255 12902 1103181 *141.35 9900 24571 c08943.04476> <04476,08943>
foe Ban.dig Calculu.on As-FoundFosretop 28.23 2455 15.332 4 01 95.56 6708.63 -50 52 5401 113 07 [055S 0 8301 [.0 83005581 Fosopnmt eetnd u5mglobWlcomtdates GloW cooklmstoesystem has asz-ts uligrned -ith the vatncal centeoho of tc vessel The x-y plane of the global odilme system t a homzonlal pli"e (b) wth thex . alongthe hme betWeen diecentelines of Nozzles3 andII Fig. 2. Latest footprint estimated from "dental mold".
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Temperature ( 0F) 0 200 400 600 180 . ...... - -,..... .- I.... ... -. ....... . .
0 0.96 Data from Table 13 160 . (unirradiated) N NUREG/CR-551 1 0.88 C N in 140 .
0.8 .2-0.72 C 120 - I
. 0.64 ^=
100 -- 0.56
. 0.48 80 0.4 60 ---
-100 0 100 200 300 400 1010412002 K2 ptw (a) Temperature (*C)
Temperature (0F) 0 200 400 600 4UU 0 Data from Table 13 350 (unirradiated)
NUREGICR-5511 Un 300 In -
-o 250 200 k Applied Tearing Modulus I.- 150 / ~at 6.4 MPa (0.928 ksi) a a, 2L = 50.8 mm (2.0 Inches) t = 6.35 mm (0.25 inches) 100 Applied Tearing Modulus______ ->8 at 8.2 MPa (1.19 ksi) 50 I 2L = 25.4 mm (1.0 inches) t = 6.35 mm (0.25 Inches) 0 _
-100 0 100 200 300 400 10/25/2002 K2 ptw (b) Temperature ( 0C)
Fig. 3. Ductile tearing data for three-wire series stainless steel weld overlay cladding from Table 13 of NUREGICR-5511: (a) J 1, data from unirradiated specimens and (b) tearing modulus data from unirradiated specimens 6
Fixed-Grip Boundary on Outer Edge 4H 1w 9277'2002
.1- CA5 a, - 4.39 inn,(0 25)..I L -25 4 .. , (I 0 In) 11 -76 1 ,10mm (2 09076 In )
(a) vess-Fixed-Grip Boundary on Outer Edge prw IO1I2vO 2Lh, - 312 a I5R,$ mm (0 06251I.)
,,N L - 25.4 an. (I D au 11= 76 160m..(2 990SIn )
Arms - It 2264mm' (2.25 In)'
(b)I Fixed-Grip Boundary on Outer Edge 2L'. 1t..
~~~~
I i/ I0*Is_).4.20I2_s
~. 1,.30(01251n.)
11761605 mm('907 in.)
Are-I.26.4 ,(28.25 .?)
(c)
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, 2LIa = 32), and (c) Model 9.1D3 (alt = 0.05, 2LIa = 160) (Task 9.1D) 7
Flied-Grip Boundary on Outer Edte (d)
Fixed-Grnp Boundarv un Outer Edge 11 H.. 3flU.O(1'l7ih) 1 (e)
Fixed-Grip Booudan unOuter dge IIA1-5-k0 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 9.1D5 (alt = 0.25, 2L/a = 16), and (IT)Model 9.1D6 (alt = 0.05, 2LIa = 80) (Task 9.1D) 8
Fixed-Grip Boundarv on Outer Edge (g) '4r Fixed-Grip Boundan on Outer Edge C-9lw5(*2 ID Fixed-Grip Boundars on Outer Fdge 1u35.1t35b An.-jL4 23 2ta (i)
Fig. 4. (continued) Finite-element models used in calculating applied J-integrals produced by pressure loading of burst disk: (g) Model 9.1D7 (alt = 0.5, 2LIa = 3) (h) Model 9.1D8 (alt = 0.25,21/a = 6), and (i) Model 9.1D9 (alt = 0.05, 2L/a = 30) (Task 9.1D) 9
Pressure (ksi)
-n 1 2 3 4 5 6 7 8 32 500 2.8 aa3175mm aft 0.5 2.4 c E 4001 0.
02 2 -
P- 2Ua t16 2Ua =3 Ci 3001 1.6 6 tM 02 4) 200 2Ua8 / 1.2 E 08 100
' k - ------ - -.--------- ----- 04 a A CD 10 20 30 40 50 60 Pressure (MPa) 10.'2.1'232 K3 3pt.
(a)
Pressure (ksi) enn 1 2 3 4 5 6 7 8 2Ua=16 3.2
,a 2Ua 32 p 500 2.8 a 15875 mm -
/aft= 025l 2.4 E 4001 02
, 2Ua.6 2 -V S0
-Z 300 C 16 C
q IM 2001 1.2 08 2 3s 100 04 0
C D 10 20 30 40 50 6tLo (b) Pressure (MPa) 10'24 2002 K4 pDN Pressure (ksi) 1 2 3 4 5 6 7 8 600
-3 .2 500 ii -2 .8 4
2 0.
E 400 ~
02 iW 2 3001 ID CE C -1.
200 .BZ aS0.3175 mm 0 aft 0.05 100 2Ua 160.
4 2UUa3O
_._.._.._.__.__._.._.. 8 . _.._
a 0 10 20 30 40 50 60 (c) Pressure (MPa) IC,24202 K5 pStw Fig. 5. J-integral driving forces from three finite-element models as a function of applied pressure: (a) alt = 0.5, (b) alt = 0.25, and (c) a/t = 0.05.
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60 t = 6.35 mm (0.25 inches) 8 50 _ Plastic Coll.apse 2L = 0.375 in.
, _ 1._ . ...
7 ^U)
,', 2L = 1.0 in.
M t ' .E _
_>// 14-
/ I~ 2L =2.0Oin.
0n 40 I- 6E b 5% / , / I .
n 5 Mn
,,,, A.:
c, 5%. ,/
., a) 1.o .J_- a.' U)
- 0. 30 %, I 4 'EL-
\ \ 5%, \_
C.,
20 3 o 0 ,SSet-point pressure
- .%trOjp~ratles- ------ " = 0JiD I.
-p. re , . I
'I-10 2
-'--- -,2L=1. I0in ILIlllIUI 1OI UJULUIt IVCdI I I
- 2L = 2.0 in 0 ! , 0 0 0.1 0.2 0.3 0.4 0.5 0.6 1012412002.K2 ptw alt Fig. 6. Comparison of critical pressures for two failure modes as a function of relative flaw depth. Three flaw lengths ( 2 in. (50.8 mm), 1 in. (25.4 mm), and 3/8 in. (9.525 mm))
were used in the current analysis.
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