ML20196K127
| ML20196K127 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 07/01/1988 |
| From: | Counsil W, Woodlan D TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| TXX-88543, NUDOCS 8807060518 | |
| Download: ML20196K127 (3) | |
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Log # TXX-88543 F 7 File # 10010
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903.6 r
C Ref # 10CFR50.34(b)
TilELECTRIC July 1, 1988 E,I,ESd5,U,,,
U. S. Nuclear Regulatory Commission ATTN: Document Control Desk-Washington, D. C.
20555
SUBJECT:
COMANL E PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50-445 AND 50-446 ADVANCE COPY OF FSAR REVISION RELATING TO JET IMPINGEMENT Gentlemen:
Attached is an advance copy of a revision to FSAR Section 3.6B related to the determination of the jet cone shape for jets discharging from high energy pipe breaks. The location of the specific change is indicated by a solid revisior, bar in the margin with the word "Draft". Also attached is a detailed description of the change and its relative significance group.
This revision is currently scheduled to be included in the r. ext FSAR amendment.
Very truly yours, W. G. hJ W. G. Counsil By:
D. R. Woodlan Docket Licensing Manager l
l BSD/bsd Attachment c - Mr. R. D. Martin, Region IV l_
Resident Inspectors, CPSES (3) l
$0#IOcc!$$0h5 p00 t \\
l 400 North Olive Street LB 81 Dallas. Texas 7201
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I,.'Atta'chnent to TXX-88543-
' July 1, 1988 Page 1 of 2 CPSES/FSAR 71 la.
Jet Category and Geometry 71 l
The area of the break is assumed to be equal to the flow area of
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the ruptured pipe. All the high energy line break Jets can be l
summarized into the following three categories:
71 l
a.1 Category I Jets - Non-Expanding Jets 71 l
For the liquid jets whose temperature is below the j
saturation temperature at ambient pressure, the initial l
free expansion does not occur.
Incompressible liquid jets l
are assumed to travel with no increase in jet area.
l However, for target identification a conservative zone of l
influence of two diameters is utilized.
The pressure is l
assumed to be un) form throughout the jet area.
71 l
a.2 Category II Jets - Steam and Flashing Water Jets which meet j
the Criteria of tiUREG-2913:
71 l
The high energy two-phase jet is a complicated l
multidimensional flow phenomena.
The high pressure and j
high temperature fluid that exits the break expands with j
supersonic velocities downstream of the break.
Upon l
encountering a target (or obstacle) a shock wave forms in l
the flow field, and it is the thermodynamic properties l
downstream of this shock that determine the pressure field l
and load on the target. A multidimensional analysis, such l
as demonstrated in fiUREG/CR-2913 (25), more realistically Draft evaluates the thennodynamic properties of these jets.
The jet cone shape for these Category II jets is a function of the break initial conditions (i.e., temperature and pressure).
These jet shapes are determined by using the flVREG/CR-2913 contour curves and are used to establish the jet zone of influence for target identification.
The 71 l
ftVREG-2913 model provides a method for calculating target l
loads for initial pipe rupture fluid conditions of pressure l
between 60 and 170 bars (870 psia -2466 psia) and with
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subcooling of 00C (00F) to 700C (1260F).
Draft Version 3.68-34
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Attachment to TXX-88543 July ~ 1, 1988 Page 2 of 2 FSAR page number DESCRIPTION 3.68-34 Revision:
Replaces statement that Category II jets are assumed to expand radially at a 45 degree angle, with a statement that describes how jet shape is determined. NUREG/CR-2913 assumes.a 45 degree constant radial expansion as an approximation of the jet
. shape for the typical pipe break.
The actual jet shape is a function of the pipe break initial conditions (i.e., pressure and temperature).
The jet shapes for various pressures and temperatures are provided in the NUREG as a series of contour curves..The zone of influence calculations utilize actual jet cone shapes which are determined from the NUREG contour curves.
(88-599) Group 2
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