ML20133B541
| ML20133B541 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 12/19/1996 |
| From: | BALTIMORE GAS & ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20133B014 | List: |
| References | |
| NUDOCS 9701060006 | |
| Download: ML20133B541 (4) | |
Text
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4 ATTACHMENT (4) i i
FLAW EVALUATION CALCULATION I
h 9701060006 961219 PDR ADOCK 05000317 P
PDR Baltimore Gas and Electric Company December 19,1996
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Purpose:
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This calculation is intended to demonstrate that the pin hole found in 4' HC-23-1005 will not have i
any impact on the strudural integrity of the line with regard to reinforcement of the pipe section.
This calculation does not check global loads (e.g., pipe stresses), these loads have been evaluated via Calc. 95-0135.
Inputs:
1)
The piping configuration is as shown on SK-M-608 sh 10.
.)
The pipo dimensions are as follows:
4'sch 10s pipe.
OD 4.5" i
Thickness 0.120" 3)
The material is permitted to be either A-312 or A 376 TP 304. This evaluation is insensitive to any differences between these two materials specifications.
l 4)
The piping is seamless pipe with a join' officiency factor of 1.0 5)
The Code of Record for this piping is B;l 7 Cl 21969 with 1971 addenda Assumptions:
The indication is similar to an unreinforced circular opening. This is based on the PT and UT results. There was no sign of linear or planar type indication. Furthermore, the indication is too i
small to represent a volumetric defect at this time. Use of the LEFM methodology outlined in GL j
90-05 would not yield meaningful results with the geometry and defect characterization.
1 Therefore, it is appropriate to utilize branch reinforcement rules to bound the defect in a gross manner.
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Methodology:
The impact of the defect on the local section will be shown to be of no local structural consequence using area reinforcement rules from the original construction Code. Other j
evaluations of this degraded condition have checked piping stress levels and found that they were well below Code allowable. This evaluation is limited to local hoop effects only.
The reinforccment for a 1' hole will be checked to demonstrate that it has no impact on the required section strength with regard to hoop stress. The indication that has been observed is too small to measure directly but, is much staaller than 1*. It could be approximated at 1/16 to 1/32". Furthermore, the indication is thought to be caused by a " bum-through* during original construction. The stainless steel material is not susceptible to degradation due to any type of conosion at this location which would cause this open to enlarge.
The calculation is shown on the next page.
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Conclusions:==
By virtue of gross size difference between the 1* opening and the actual opening, it is clear that
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there is no impact on the section integrity. In addition, there will be continued monitoring of the a
line such that if a measurable change in the indication size or characteristics occurs, the gross j
margin cantained herein will ensure no challenge to the structural integrity will occur prior to identification.
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- Unreinforced opening evaluation of B31.1104.3.1 (1992 ed)
Note: B31.71969 ed w/1972 add. refers to B31.1 Evaluation of tmh (Requiredmin wan);
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1,,a a 2.(SE + P y)
P 200 Design Pressure (psi)
Do 4.5 Outside diameter (in)
SE 17800 Allowable Stress (psi) y 0.4 Coefficient for ferritic steel LJe 24 ServiceWe(months) rete O Corrosion Rete (byyr)
A 0 Corrosion allowance (in) j l
in*
0.03 Required min wall LAW Eqn (3) 104.1.2 (in)
Evaluation of Reinforement Requirements The required reinforcement is-IA,=tsdi I
tmh 0.03 Required min well IAW Eqn (3) 104.1.2 (in) di 1 Assumed size of an un-rein'orced opening A7 0.03 Required reinforcement area (in"2) i 1
Area available for reinforcement l J 4 J, + J 4 J,4 J. > J, I
Ai = (2 d - di)-(Ta - t )
tb 0 Thickness of branch (in)
A 0 Corrosion allowance (in)
Th 0.12 Actualwallin header (in) d2' O.62 (in)
(tb-A)+Th +d1/2 d2" 1 (in) di d2 is the greater of di or (tb-A)+Th +di/2 d2 1 half width reinforcing zone (in) l A1 0.09 area provided by excess run wall (in)
In this instance A2 through A5 are zero since the branch connection is assumed to fail Excess reinforcement A1-A7 0.07 Therefore this is acceptable.
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95-0135 SHUTDOWN HEAT EXCHANGER PIPING
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5/24/95 AutoPIPE+'4.50 RESULT PAGE 20 3
ASME / ANSI B31.1 (1967)
CODE COMPLIANCE (Moments in ft-lb
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(Stress in psi
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Point Load In-Pl. Out-Pl. Torsion S.I.F Eq. Lc.ud Code Code nrma combination Moment Moment Moment In Out no. type Stress Allow.
1 70 F+ Max P HOOP 4286 15600 GR + Max P O
32 0 1.00 1.00 SUST 1946 15600 Cold to T1 0
15 0 1.00 1.00 ( 8) DISP 104 27275 i
Sus. + R1 27 166 79 1.00 1.00 OCC 3024 18720 Sus. + R2 41 268 119 1.00 1.00 OCC 3766 28080 v
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75 Max P HOOP 4286 15600 1
GR + Max P O
4 0 1.00 1.00 SUST 1756 15600 i
Cold to T1 0
42 0 1.00 1.00 ( 8) DISP 289 27275 Sus. + R1 159 365 79 1.00 1.00 OCC 4497 18720 l
Sus. + R2 240 658 119 1.00 1.00 OCC 6566 28080
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CALC. NO. W~'35 Wo
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