ML20198N503
| ML20198N503 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 10/31/1997 |
| From: | Andreychek T, Forgie A, Ofstun R WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML20198N501 | List: |
| References | |
| WCAP-14407-01, WCAP-14407-1, WCAP-14407-R, WCAP-14407-R00, NUDOCS 9711050123 | |
| Download: ML20198N503 (53) | |
Text
_ _ _
Westinghouse Non Proprietary Class 3 O
I Section 12 4
Clime Noding Study
'l i
}
l i
l T. S. Andreychek A. Forgie R. P. Ofstun i
i e
i f
i i
l P
I l
[
1-e l
lO 4
1 o:\\3221w-12.non:1b-101397 l
l 9711050123 971023 PDR ADOCK 05200003 A
PDR I
111 TABLE OF CONTENTS g
)
2 LIST O F TA B LES........................................................ iv LIST OF FIG URES........................................................ v EXEC UTIVE
SUMMARY
.................................................. vil i
12.1 INTRODUCTION
................................................ 12 1 i
12.1.1 Background............................................... 12-1 12.1.2 Problem Statement
.........................................123 12.1.3 Approach................................................ 12-3 12.1.4 Selected Parameters......................................... 12-3 12.1.5 Success Criteria............................................ 12,
12.2 MODEL DESCRII'rIONS......................................... 12-4 12.2.1 Annulus Clime Model....................................... 12-4 12.2.2 AP600 Containment Model Clime Noding Sensitivity Studies......... 12-6 12.3 RESULTS...................................................... 12-8 12.3.1 Annulus Clime Model....................................... 12-8
- [
t 12.3.2 AP600 Containment Model Clime Noding Sensitivity Results......... 12-9 u
12.4 SUMMA RY................................................... 12-10 12.4.1 Annulus Clime Noding Study....,..............,,. 3......... 12-10 12.4.2 AP600 Model Clime Noding Sensitivity Results................... 12-11
^
12.5 REFE RENCES................................................. 12-11 i
A Clime Noding Sensitivity Study.
October 1997 o:\\3221w 12.non.lb-101397
iv LIST OF TABLES O
Table 121 Input Parameters for Annulus Clime Model Sensitivity Stu dy........................................... 12-6 Table 12-2 Predicted Heat Removal Rates for Various Clime Noding Schemes...................................... 12-8 O
O Clime Noding Sensitivity Study October 1997 o:\\3221w-12.nort1bl01397
v LIST OF FIGURES A
('-)
Figure 121 Westinghouse-GOTHIC Clime Wall Source Term Models........... 12-12 Figure 12-2 Simplified Line Diagram of Annulus Clime Model................ 12-13 Figure 12-3 Noding Diagram, 8 Clime Node Model......................... 12-14 Figure 12-4 Comparison M Transient Heat Transfer Rates; Case 1.............. 12-15 Figure 12-5 Compdson of Transient Heat Transfer Rates; Case 2.............. 12-16 Figure 12-6 Comparison of Transient Heat Transfer Rates; Case 3.............. 12-17 Figure 12-7 Comparison of Transient Heat Transfer Rates; Case 4.............. 12-18 Figure 12-8 Comparison of Transient Heat Transfer Rate Differences; Case 1...... 12-19 Figure 12-9 Comparison of Transient Heat Transfer Rate Differences; Case 2...... 12-20 Figure 12-10 Comparison of Transient Heat Transfer Rate Differences; Case 3...... 12-21 Figure 12-11 Comparison of Transient Heat Transfer Rate Differences; Case 4...... 12-22 Figure 1212 Comparison of Heat Flu c Profiles; Time t = 2000 Seconds; Case 1..... 12-23 Figure 12-13 Comparison of Heat Flux Profiles; Time t = 2000 Seconds; Case 2..... 12-24 Figure 12-14 Comparison of Heat Flux Profiles; Time t = 2000 Seconds; Case 3..... 12-25 Figure 12-15 Comparison of Heat Flux Profiles; Tip ? = 2000 Seconds; Case 4..... 12-26 Figure 12-16 Comparison of Film Temperature Prot %
Time t = 2000 Seconds; Case l........
..................... 12-27 Figure 12-17 Comparison of Film Temperature Profiles; Time t = 2000 Seconds; Case 2................................ 12-28 7
I ~J Figure 12-18 Comparison of Film Temperature Profiles Time t = 2000 Seconds; Case 3................................ 12-29 Figure 12-19 Comparison of Film Temperature Profiles Time t = 2000 Seconds; Case 4................................ 12-30 Figure 12-20 Comparison of Air Temperature Profiles; Time t = 2000 Seconds; Case l................................ 12-31 Figure 12-21 Comparison of Air Temperature Profiles; Time t = 2000 Seconds, Case 2................................ 12-32 Figure 12-22 Comparison of Air Temperature Profiles; Time t = 2000 Seconds, Case 3................................ 12-33 Figure 12-23 Comparison of Air Temperature Profiles:
Time t = 2000 Seconds, Case 4................................ 12-34 Figure 12-24 AP600 Containment Model Clime Noding Pattern................. 12 35 Figure 12-25 AP600 Containment Model Double Vertical Clime Noding Pattern.... 12-36
- Figure 12-26 AP600 Containment Model Double Stack Clime Noding Pattern...... 12-37 Figure 12-27 AP600 Containment Model Double Mesh Point Clime Noding Pattern. 12-38 Figure 12-28 Pressure History, AP600 Containment Model; Double Clime......... 12-39 Figure 12-29 Heat Rejecion History, AP600 Containment Model; Double Clime.... 12-40 Figure 12-30 Integrated Heat Rejection, AP600 Containment Model; Double Clime.. 12-41 Figure 12-31 Pressure History, AP600 Containment Model; Double Stack......... 12-42 g)
Figure 12-32 Heat Rejection History, AP600 Containment Model; Double Stack..... 12-43
(
Clime Noding Sensitivity Study October 1997 on3221w-12.non.lb-101397
vi 2
LIST OF FIGURES (cont.)
Figure 12-33 Ir.tegrated Heat Rejection, AP600 Containment Model; Double Stack... 12-44 Figure 12-34 Pressure History, AP600 Containment Model; Double Mesh......... 12-45 Figure 12-35 Heat Rejection History, AP600 Containment Model; Double Mesh..... 12-46 Figure 12-36 Integrated Heat Rejection, AP600 Containment Model; De,uble Mesh... 12-47 O
O Clime Noding Sensitivity Study octoler 1997 o:\\3221w-12.non.lb-101397
..____.-_.____..~.m
._._.___._..-.___s._.
+
4 vil EXECUTTVE
SUMMARY
!O ThelGOTHIC code (Refs.1 and 2) is a state-of the-art program for modeling multi phase flow.
The code solves the integral form of the conservation equations for mass, momentum, and
- energy for multi-component, two-phase flow. The conservation equations are solved for three fields; continuous liquid,: liquid drops, and a steam / gas phase. The three fields may be in i-thermal non-equilibrium within the same computational cell, Relative velocities are calculated i
for each field, as well as the effects of two-phase slip on pressure drop. Heat transfer between
^
the phases, surfaces, and the fluid are also allowedi The COTHIC containment analysis code j-was modified by Westinghouse to include mechanistic convective heat and mass transfer i
correlations, a liquid film tmcking model, a one-dimensional wall conduction model, and wall-to-l
' wall radiant heat *ransfer to model heat removal by the passive containment cooling system
}
(PCS). The code with these modifications is called Westinghouse-GOTHIC, and is abbreviated l
as WGOTHIC (Sections 3.2 and 3.3).
1 i
i A solution technique that includes wall-to wall radiation at the conditions expected for the -
AP600 plant design necessitates a close coupling of the participating walls. This coupling is 3 -
accomplished by assigning boundaries that de. fine the portions of the various walls that radiate l
j
.to one another. Consistent with the basic formulation implemented for the GOTHIC code that
[
considers conductors or heat sinks to be energy sink or source terms, code modifications that incbde wall-to wall radiant heat transfer can be thought of as the addition of a special type of g
j_
conductor group. This special conductor type or group consists of a set of walls that radiate to each other and interface with GOTHIC fluid cells through mass and energy source terms. The
- term clime, meaning region, is used to differentiate and distinguish this special conductor _ type from those already existing in GOTHIC terminology.
At issue is the sensitivity of the calculations to the clime noding p:dtern used in the PCS
- evaluation model. To addrer' this issue, models with various noding patterns were used to perform calculations to investigate the effect of noding: detail on calculated results. A comparison of these results demonstrem the methodology is not sensitive to the clime noding structure over the range of noding patterns and boundary conditions studied.' Further, these -
dadies also demonstrate that results obtained with the WGOTHIC AP600 containment model are not sensitive to changes in the clime or annulus noding structure selected.
This, it is concluhd that the WGOTHIC AP600 containment model with 7 clirre nodes is
- adequate to predict the PCS performance.
O
- Clime Noding Sensitivity Study October 1997 c:\\3221w 12.non.lb-104397 -
u
12 1
., g 12.1 IN11tODUCT10N' O
This section provides background associated with the EGOTHIC clime model, a statement of the issue associated with the application of the clime methodology, a description of the cpproach 1eveloped and taken to address the issue, a summary of the results of the actions taken and the conclusions drawn from a review of those actions.
12.1.1 Background A detailed description of the GOTHIC code and the modifications implemented in the amended code as MGOTHIC is presented in Section 3.2 of this report. A detailed description of the EGOTHIC clime model is presented in Section 3.3. For completeness, these description.s are summarized here as backgrouna material.
HGOTHIC Code.
As noted in Section 3.2 of this report, the GOTHIC code (Refs.1 and 2) is a state-of-the-art program for modeling multi-phase flow. The code solves the integral form of the conservation equations for mass, momentum, and energy for multi-component, two phase flow. The GOTHIC containment analysis code was modified by Westinghouse to include mechanistic convective heat and mass transfer correlations, a liquid film tracking model, a one-dimensional wall conduction model, and wall-to-wall radiant heat transfer to model heat removal by the PCS. These features are collectively known as the clime model, which is described in the following section. The code t
with these modifications is called Westinghouse GOTHIC, and is abbreviated as EGOTHIC.
EGOTHIC Clime ?.1odel A solution technique that includes _ wall-to-wall radiation at the conditions expected for the AP600 plant design necessitates a close coupling of the participating walls. This coupling is accomplished by assigning boundaries that define the portions of the various walls that radiate to one another. Consistent with the basic formu:ation implemented for the GOTHIC code that considers. conductors or heat sinks to be energy sink or source terms, code modifications that include wall-to-wall radiant heat transfer can be thought of as the addition of a special type of conductor group. This special conductor type or group consists of a set of walls that radiate to each other and interface with GOTHIC fluid cells through mass and energy source terms. The term clime, meaning region, is used to differentiate and distinguish this special conductor type from those already existing in GOTHIC terminology.
For the APB containment model, a clime node is a horizontal slice of the containment structure consisting of the following:
o Clime Noding Sensitivity Study -
octobn 1997 c:\\3221w-12.non.lb-101397
1 I
12 2 The heat and mass transfer source terms from the containment volume to the shell Cond 1ction through tnt: shel!
Heat and mass traMer.,ource terms from the exterior shell to the riser air flow channel Radiation from the exterior shell to the in*erior baffle a
Heat and mass transfer source terms to the interior baffle from the riser air flow channel Conduction through the oaffle Heat and mass ti nsfer source terms from the exterior baffle to the downcomer air flow channel Radiant heat ansfer from the exterior baffle to the interior surface of the shield building
=
Seat trarvier somce terms to the interior surface of the shield building from the dowrc.m air flow channel Cor.e.ction through the wall of the shield building O
Both radiant and convective heat transfer from the exterior surface of the shield building to the environment An AP600 three-conductor clime is shmyn schematically in Figure 12-1.
The internal containment vessel volume, riser air flow channel volume, downcomer air flow channel volume, and environment volume are separate computational cells or fluid volumes in the model. The shell, baffle, and shield building walls are one-dimensional conductors representing solid wall structures between the computational cells. These conductors are further subdivided into regions of different materials with different mesh sizes.
Othe %atures of the clime modeling technique that support simulation of AP600 PCS performance are:
Stacks of climes are used to track the change in liquid flow rate on the conductor surfaces as it flows downward. The film flow rate between adjacent vertical clime shell conductor surfaces is reduced as water evaporates and provides for identification of "dryout" on the vessel surface.
O Clime Noding Sensitivity Study October 1997 o:\\3221w 12.non.lb-101397
12 3 The radiation boundary conditions implicitly couple the temperature of the clime surfaces that face each other, All clime surfaces are also coupled explicitly to computational cells (fluid volumes) for convective heat and mass transfer.
. The following mechanisms of thermal transport are modeled in a clime; convective heat transport, steam condensation, conduction, liquid film evaporation, wall-to-wall radiation, and liquid film enthalpy transport, The details of the clime model are described in Section 3.4, Clime Heat and Mass Transfer Models, Section 3.5, Clime Film Model, and Section 3.6, General Clime Fquations, of this report.
12.1.2 Problem Statement Simply stated, the objective of this effort is to demonstrate that the clime calculations are insensitive to variations in the noding pattern employed.
12.1.3 Approach I
The approach taken to address the problem statement given above is to:
i O
i l
Perform a clime node sensitivity study using a two-channel annulus model with a constant temperature boundary condition. For this task, the number of climes in the model will vary from 4 to 16. This two-channel annulus model will provide for thermo-fluid conditions similai to those expected in the AP600 plant.
Perform sensitivity calculations with an APB containment model for which the number of climes, stacks, and conductor layers are varied.
12.1.4. Selected Parameters The following thermal-hydraulic parameters are used in evaluating the comparison of various model predictions and the comparison of predictions to test data.
Containment pressures (for the AP600 model only)
Temperatures - cooling air and liquid film (fc. the two-channel annulus model only)
-=
Heat fluxes and/or heat rates from the shell O
Clime Noding Sensitivity Study October 1997 o:\\322Iw 12.non.lb-101397
13-4 These parameters are primary indicators of the heat transfer process and were selected as a basis for evaluating the sensitivity of the calculated results to noding patterns.
12.1.5 Success Criteria The noding pattern used for a model may affect the results of a calculation. For the purpose of this study, the following success criteria are used to evaluate the significance of change in calculated results with increasing detail in clime noding:
Success Criteria:
The change between results calculated with two noding patterns is defined to be negligible; if:
1)
The variation in results between two successive noding patterns is less than [ ]"# percent.
2)
The variation in results from successively finer noding patterns is decreasing
[
O jae Thus, the criteria listed above establishes the variation between results obtained from different noding patterns must be small, and the variation must be converging as the noding pattern is increased.
12.2 MODEL DESCRIPTIONS The sensitivity of the thermo-fluid calculations of the WGOTHIC clime methodology to the number of nodes associated with the flow channel was investigated using a two-channel annulus model. This section presents descriptions of the model and the boundary conditions used in this investigation.
12.2.1 Annulus Clime Model Model Description A two-channel model was developed to study the effects of increasing the number of climes over a wide range of film flow rates and film temperatures and is shown schematically in Figure 12-2.
The modeled heated height was [ ] # feet. This height was chosen to promote the calculation Clime Noding Sensitivity Study October 1997 oA3221w-12.non.lb-101397
12 5 of velocities in the model representative of the lower bound of the range expxted for AP600.
The number of climes (and corresponding annulus cells) in the heated section of the model varied between 4 and 16. Figure 12-3 presents the noding structure for the 8 clime model. The noding pattern for the 4 and 16 clime models is similar to that of the 8 clime model, having one-half and double the number of axial cells, respectively.
The annulus clime model consists of two stacks of lumped parameter cells. One stack represents the downcomer volume and the other represents the riser volume. The volumes of the riser and downcomer are (
]'# feet and [
]** cubic feet respectively. The downcomer volume was arbitrarily selected to be about twice the value of the riser volume. A set of equally spaced elevation planes crosses both the riser and downcomer to form the two stacks of luenped parameter cells. The volume, height, and vertical flow area of each cell in the riser stack and each cell in the downcomer stack is the same.
A natural draft flow of air from the downeomer through the riser develops as the riser channel is heated. Friction acts to retard the increase in air velocity. Except for the turning location and exit, the friction lengths for each flow path are equal to the cell height. The friction lengths at the riser entrance and exit are set to one half the cell height to conserve the total friction length and fL/D values between models. Loss coefficients of [
las at the dawncomer entrance and
[
]"# at the riser outlet are used to model the form losses representative of a contraction and an expansion, respectively, For the 8 clime model shown in Figure 12-3, a thermal conductor located within the heat source (Volume 9), provides a [
]*# constant temperature boundary condition for the model. A single stack of climes is used to thermally connec' the heat source with the riser and downcomer volumes. There is one clime per cell in the riser. An additional clime at the bottom of the stack is used to model the runoff film flow. The last clime in the stack is connected to three durnmy volumes. This modeling is used to allow the runoff from the last clime to collect in the drain volume (Volume 18) without affecting the heat removal in the active section of the annulus, i
Each clime has two conductors; the first one represents a [
]^# thick steel plate and the other represents an acrylic cover. The perimeter and heat transfer area is the same for each conductor on all climes.
To prevent the drain volume frorn overfilling, it is connected to a flow rate boundary condition.
The boundary flow rate for the drain volume is controlled with trips based on the liquid level in the drain volume.
These features were also included in both the 4 and 16 clime models.
Clime Noding Sensitivity Study october 1997 o:\\3221w-12.non.1b-101397
12-6 Boundary Conditions O
Four cases were considered for this study. The independent variables for each case are listed in Table 12-1.
a,c Table 12-1 INPUT PARAMETERS FOR ANNULUS CLIME MODEL SENSITIVITY STUDY The film boundary cond!tions are selected to cover a range of temperatures and flow rates considered typical for the AP600 plant. For Case 4, the film rnass flow rate is reduced to force the prediction of dryout about midway down the plate. Both the downcomer and riser are connected to a fixed pressure boundary set at [
]*# psia.
12.2.2 APB Containment Model Clime Noding Sensitivity Studies q
A schematic of the AP600 containment model clime noding pattern is shown in Figure 12-24.
l The dashed lines represent divisions between the [ ]"# climes (and cells) in the annulus. The AP600 containment model used for these sensitivity studies differs from the model described in Chapter 4 as follows:
Several thermal conductors that were specified as internal (type I) are actually external so they were corrected (changed to type X).
The loss coefficients (K values) below the operating deck were set to [ ]a# instead of
[ ]'# to better represent losses during natural circuiation daven flow.
The loss-of-coolant-accident (LOCA) rnass and energy releases were modified. The steam release is split between the two steam generator compartments after the automatic depressurization system (ADS) 4th stage is opened.
Clime Noding Sensitivity Study october 1997 o:\\3221w-12.non.1b-101397
._______._.___________.._.__m..___._
o
~
12 7 The in-containment refueling water storage tank (IRWST) drain flow function was revised to match the modified mass release rate.
e I
e Nodes 91 and 99 (at the top of the annulus) were combined into a single volume, e
3 The clime heat transfer area and nxiing structure was corrected to match the elevations used in the revised volume noding structure-p i
The thickness of conductor type.26 was changed to [ ]*# inches instead of [ ]** inches
)
C.soductors 58 and 68 were moved from Volume 5 to Volume 4 ll The heat transfer option for type 5 heat links was changed from the [
]*# option to l -
the [
]** option
[
The annulus inertia lengths were modified to use the revised ecvel subroutine in WGOTHIC Version 4.1.
A dummy clime and corresponding volumes was added to each cef the four wet stacks
=
to collect runoff flow.
.q j_ Q These amendments were made to incorporate features identified in response to review by both NRC and Westinghouse.
l The amended AP600 containment model was modified to study the following effects:
Doubimg the number of vertical climes in the AP600 containment model from [ ]*# to
[ ]*# (see Figure 12-25) k Doubling the number of stacks or radial segments in the AP600 containment model from --
[ la# to [ ]*# (see Figure 12-26)
Doubling the number of mesh points through the thickness of the clime conductors (see Figure 12-27)
The primary parameters of-iriterest selected for this rtudy of the AP600 model are the calculated transient pressure response and shell heat removal rate.
As with the amulus noding study described in Section 12.2.1, the heat transfer parameters identified in Section 12.1.4 were used to evaluate the sensitivity of the calculations to' changes lp in the rr, ding pattern used for the calculations.
t Clime Noding Sensitivity Study october 1997 o:\\3221w-12.rmrtib-101397
12-8 12.3 RESULTS O
The results of the various calculations are presented here.
.12.3.1 Annulus Clime Model The fou-est cases described in Section 12.2.1 were run using IVGOTHIC Version 4.1. Plots of the predicted heat removal rate from the plate surface, shown in Figures 12-4 through 12 7, indicate tha*. the four cases were close to steady-state conditions at the end of the 2000-second transient period. The difference between the heat rejection rates of the 4 and 8, and 8 and 16 clime models is shown in Figures 12-8 through 12-11. From these plots, it is noted that the predicted transient heat removal rate is quite insensitive to the level of clime noding detail, a change of less than 1 percent is observed for increasing the axial nodal pattern from 4 to 8 climes. The difference observed when the axial nodal pattern is increased from 8 dimes to 16 is even less.
A comparison of the predicted heat removal rate from the plate surface at the end of the transient is shown in Table 12-2.
__ a,c Table 12 2 l'REDICTED HEAT REMOVAL RATES FOR VARIOUS CLIME NODlNG SCHEMES mummmmmmm -
For the first three tests (all d~ or ;11 wet), the steady-state heat removal rate increases slightly as the number of climes u doubled from 4 to 8. Doubling the number of climes from 8 to 16 increases the heat removal rate again, but by a much smaller amount. Therefore, for these cases, the predicted heat removal rate is converging from below.
O Clime Noding Sensitivity Study october 1997 o:\\3221w-12.non.1b 101397
4
.12-9 4
[
For test case 4 (half wet), the steady-state heat removal rate decreases slightly as the number l
of climes is doubled from 4 to 8, Doubling the number of climes from 8 to 16 also decreases the heat removal rate, but by a smaller amount. Further comparisons show the predicted j-heat removal rate decreases on the top [ ]'# feet, but increases on the bottom [ ]'# feet of the model surface as the number of climes is increased. The decrease on the top [
]*# feet is 1
larger than the increase on the bottom [ ]*# feet. Therefore, the total predicted heat removal j
_ decreases as the number of climes increase in case 4. At the low flow rate for this test, the l
increased resolution of the subcooled heat flux with more climes yields a slightly lower estimate of the predicted heat removal rate, i
[
Figures 12-12 through 12-15 compare the calculated axial heat flux profiles, and Figures 12-16 through 12-19 compare the axial film temperature profiles at time t = 2000 seconds. Note, the data from the 8 and 4 clime models is represented as 2 and 4 points respectively on the plots to match the 16 points from the 16 clime model.
For the wet tests, smoother axial heat flux and film temperature profiles are calculated as the l
number of climes increases. In the cold film tests (cases 2 and 4), the heat flux decreases and film tempervure increases as the film flows from the first clime down. In the hot film test (case 3), the heat flux increases and the film temperature decreases as the film flows from the first clime down. The heat flux remains constant after the film reaches a stable evaporating temperature. For the partially wet test (case 4), the heat flux decreases rapidly and the film temperature increases to the dry surface temperature in the clime where dryout occurs.
[
The heat flux and surface temperature profiles are adequately represented with either 4,8, or l
16 climes for the dry test (case 1). The heat flux decreases linearly from the entrance (last
{.
clime) to the exit (first clime) of the channel while the surface temperature remains essentially
{
constant.
j Figures 12-20 through 12-23 compare the calculated axial air temperaturr profiles at time t =
i 2000 seconds. In all tests, the air temperature increases from the entra:p (last clime) to the exit (first clime) of the heated channel.
{
12.3.2 AP600 Containment Model Clime Noding Sensitivity Results 1
i Clime Sensitivity Results i
The number of climes and volumes in the annulus of the base model were doubled (while
- maintaining the same total volume and heat transfer area) and - the case was run using MGOTHIC Version 4.1. Figure 12-28 shows a comparison of the transient pressure for the double clime case with the base case. There is essentially no difference between the two cases.
i.O Comparisons of the transient heat rate and heat releases integrated over height of the model are i
Clime Noding Sensitivity Study (ktober 1997 1
o:\\3221w-12.non.1b-101397 i
18 10 shown in Figures 12 29 and 12 30. Again, there is essentially no difference between the two g
cases.
By this comparison, it is concluded that the transient pressure and shell heat removal rates calculated by the AP600 containment model are not sensitive :o the number of climes.
Stack Sensitivity hesults The number of stacks of climes in the base model were doubled (while maintaining the same total heat transfer area) and the case was run using }yGOTillC, Version 4.1 Figure 12 31 shows a comparison of the traasient pressure for the double stack case with the base case. There is essentially no difference between the two cases. Comparisons of the transient heat rate and heat releat,es integrated over the height of the rr adel are shown in Figures 12 32 and 12 33. Again, there is essentally no difference between the two cares-These comparisons show the transient pressure and shell heat removal rate calculated by the AMO containment model are not sensitive to the number of stacks.
Mesh Point Sensitivity of Conductor Node Results The number of mesh points through the thickness of each of the three conductors (shell, baffle, and concrete) that make up each clime in the base model was doubled and the case was run h
using.\\VGOTillC Vctsion 4.1. Figure 12 34 shows a comparison of the transient pressure for the double stack case with the base case. There is essentially no difference between the two cases.
Comparisons of the transient heat rate and heat releases integrated over the height of the model is shown in Figures 12 35 and 12 36. Again, there is essentially no difference between the two cases.
From these comparisons, it is concluded that the transient pressure and shell heat removal rates calculated by the AP600 containment model are not sensitive to the number of nodes within the conductors that comprise each clime.
114
SUMMARY
l'.:.4.1 Annulus Clime Noding Study A two-channel annulus model was exercised over a range of film flow rates, and film temperatures with the code calculating air velocities associated with natural draft heating. For the cases considered, increasing the number of climes was abserved to have no significant effect on the predicted heat removal rate. That is, the predicted heat removal rate was insensitive to the number of clime nodes used in the model. The predicted heat removal rate converges. in all cases considered. Increasing the number of climes resulted in smoother axial heat flux and film Clime Noding Sensitivity Study cktober 1997 o \\3221w 12.non Ib-101397
12 11 temperature profiles for the wet tests. Adequate nial heat flux and temperature profiles were 7
i predicted without increasing the number of climes for the dry cases.
s 12.4.2 AP600 Model Clime Noding Sensitivity Results Using the amended AP600 containment model as a base, the effect of doubling the number of clime nodes, doubl'ng the number of stacks, and doubling the number of conductor mesh points was studied. In each case, code calculations were found to be unaffected by the variations in the model features.
These studies demonstrate that results obtained with the AP600 containment model are not sensitive to changes in the clime and annLas noding. Therefore, it is concluded that the
}yGOT111C AP600 containment model with 7 climes is adequate to predict PCS performance.
12.5 REFERENCES
1 Letter NTD-NRC-95-4563, D. A. McIntyre to T. R. Quay (NRC), GOTHIC Containment Analysis Package," Version 4.0, Volume 1: Technical Manual; Volume 2: User's Manual; Volume 3.
2 Letter NTD-NRC-95-4462, N. J. Liparulo to T. R. Ouay (NRC), EPRI Report RA 93-10, pQ "GOTIllC Design Review, T8.nal Report," May 15,1993.
,Q Clinie Noding Sensitivity Study cktober 1997 o:\\3221w 12.non.lb.101397
13 12
~
st O O
Figure 12-1 Westinghouse-GOTHIC Clime Wall Source Term Models Clime Noding Sensitivity Study
- k**'1"7 oA3221w.12.non ib 10lN7
12 13 u
O 1
/M
'Q Figure 12-2 Simplified Line Diagram of Annulus Clime Model
~
-- Clime Noding Sensitivity Study october tw7 c:\\3221w 12.rmlb 101397
=
=
=
--a_.-----_----
13 14 A,C O; l
e i
i l
i l
l Figure 12-3 Noding Diagram,8 Clime Node Model h
l l
Clime Noding Sensitivity Study october 1997 o:\\3221w 12.non.1t> 101397
4-4 1
12 15 2
1, -
i i
s.c.
l 4
i I.
L f.
1 d
5 t
i 1
i 1
i e
l-5 I
4 1
i i
1 l
I i
'?
4 1
1 4
i i
i-1 1
l i
i i
Figure 12-4 Comparison of Transient Heat Transfer Rates; Case 1
. Clime Noding Sensitivity Study
- october 1997 -
o \\3221w 12.non.lb 101397
--,n
--,.a-,--..n,+,~.,n._,-n
,,a,
-~,, +,.
,,n.,
,,w...,.,-.,n,-
.,,,_,.n.-..,n,..n.,
,.n.w-.,,..-,
12 16 ac i
i 1
l l
4-0\\
Figure 12-5 Comparison of Transient Heat Transfer Rates; Case 2 Clime Noding Sensitivity Study october tw7 0:\\3221w 12.non.lb101397
12 17 A,C C
/
O
(\\.
Figure 12-6 Comparison of Transient Heat Transfer Rates; Case 3 Clime Noding Sensitivity Study October 1997 o \\3221w.12.non.1b-101397
12 18 a.c 9 O
l Figure 12-7 Comparison of Transient Heat Transfer Rates; Case 4 h-l Clime Nodmg Sensitivity Study October 1997 o:\\3221w-12.imlb-In1397 I
12 19 a.c 1 (
i a
1 1
E
~
Iv J
s 1
e d
i
- Q Figure 12-8 Comparison of Transient Heat Transfer Rate Differences; Case 1 Clime Noding Sensitivity Study October 1997 1
o:\\3221w 12.nortit> 101397
13-20 a,c O O
Figure 12-9 Comparison of Transient Heat Transfer Rate Differences; Case 2 Clime Noding Sensitivity Study
- '" 1"7 c:\\3221w-12mn.lb101397
12 21
~
~
a.c Figure 1210 Comparison of Transient Heat Transfer Rate Differences; Case 3 Clime Noding Sensitivity Study october 1997 a\\3221w 12.non lb 101397 l
,,.._,a..____... _
13 22 a.c O O
Figure 12-11 Comparison of Transient Heat Transfer Rate Differences; Case 4 Clime Noding Sensitivity Study october 1997 o:\\3221w.12.non.1b-101397
12 23 f'
n.c t
O
' (j Figure 12-12 Comparison of Heat Flux Profiles; Time t = 2000 Jeconds; Case 1 Clime Noding Sensitivity Study october 1997 c:\\3221w-12.non.1b 101397 I
l 12 24 es O
~
Figure 12-13 Comparison og gea, Flux Profiles: Time t = 2000 Seconds; Case 2 O
Chme Noding Sensitivity Study Octotwr 1997 as32:1w.12.non 1t> 101397
i 9
s 12 25-1
,4 j-a,c 1
i f
I 4
t 4
1 l
I 2
0 a
I r
4 i
J I
i
!.1 I..
4 1
1 i
i e
j f-1 c
i 4
i 1
1 4
s i -
i t_
r i
i!
i i
f u
lp 1
l'-
~'
s 4
l
,{
Figure 12-14 Comparison of Heat Flux Profiles; Time t = 2000 Seconds; Case 3 4
I Clime Noding Sensitivity Study october 1997 -
l.
o:\\3221w 12.non.1b 101397 l
f e
e m-,
ueutr,,,n--,.re,-,-
..wv-,-e
,-r-m e en-m%e---esw---
- e
-. - -- - - - - - +. - - -,. - + = -.
--=--*r
13 26
~
a.c 9 O
Figure 12-15 Comparison of Heat Flux Profiles; Time t = 2000 Seconds; Case 4 Clime Noding Sensitivity Study N '**'l'97 c:\\322Iw.12.non.1b101N7
l 12 27 ex 0
t V(3 Figure 12-16 Comparison of Film Temperature Profiles; Time t = 2000 seconds; Case 1 Clime Noding Sensitivity Study October 1997 c:\\3221w.12.nm.1b 101M7
12 26 ex 0 O
Figure 12-17 Comparison of Film Temperature Profiles; Time t = 2000 seconds Case 2 Clime Noding Sensitivity Study (ktober 1997 o:\\3221w.12.non.1t*101397
12 29
~~
s,c v
O Figure 12-18 Comparison of Film Temperature Frofiles; Time t = 2000 seconds; Case 3 Clime Noding Sensitivity Study ocue,,3,97 c:\\3221w.12.non.1t-101397
12 30 a.c O O
Figure 12-19 Comparison of Film Temperature Profiles; Time t = 2000 seconds; Case 4 Clime Nodtng Sensitivity Study N'**'l"7 n\\3221w 12.non.1b-101397
i 12 31 e,c Figure 12 20 Comparison of Air Temr ature Profiles; Time t = 2000 reconds; Case 1 dime Noding Sensitivity Study October 1997 o.\\312iw 12.non.1b-101397 -
13 32 a.c O l
O Figure 12-21 Comparison of Air Temperature Profiles; Time t = 2000 seconds; Case 2 Clune Noding Sensitivity Study october tw7 o:\\3221w 12.rmn.1b101397
12 33
~
~
O O
Figure 12 22 Comparison of Air Temperature Profiles: Time t '= 2000 seconds; Case 3 '
' Clime Noding Sensitivity Study
- *'IW7 o \\3221w 12 runtb101397
13-34 a,e O
O r
Figure 12 23 Comparison of Air Temperature Profiles; Time t = 2000 seconds; Case 4 h
Clime Noding Sensitivity Study octotwr tw7 o:\\3221w 12.non1b-101397
l 12 35 a,e O
=-
Figure 12-24 AP600 Containment Model Clime Noding Pattern
- Clime Noding Sensitivity Study october 1997
. o:\\3221w 12 mnib 101397 E 4
--._2-.-:--
12 36 j
a.c l
O Figure 12-25 AP600 Containment Model Double Vertical Clime Noding Pattern Clime Noding Sensitivity Study october 1997 c:\\3221w 12.non.lb-101397
l 12 37 l
..e
\\J (D
V
(~()
Figure 12-26 AP600 Containment Model Double Stack Clime Noding Pattern Clime Noding Sensitivity Study october 1997 o:\\3221w.12.non.1b.101397
12 38 a,e O
I l
f Figure 12-27 AP600 Containment Model Double Mesh Point Clime Noding Pattern Clime Noding Sensitivity Study october 1997 o,\\3221w 12.non.lb-101397
4 12 39 i
?
j' a,c.
)
p.
i i-i=
l I.
E i
e i
4 1.:
?
I ia-
[
t 1
1 4.
?'
i 1
1-t 4
1 1
Ii-.
i-i t,
4 4
4 E
i l-i u
9-1-
e 2-4 -
(-
i
+
4 4-i 4
1-1 1
4lQ Figure 12-28 Pressure History, AP600 Containment Model; Double Clime j
' Clime Noding Sensitivity Study october 1997 2
0:\\3221w-12.non.lb 101397
+
1 -
g.
12-40 a,c l
l O
Figure 12-29 Heat Rejection History. AP600 Containment Model; Double Clime C1'me Noding Sensitivity Study October 1997 o.J221w-12.non.1b-101397
12 -
e,c.
O i
\\
Figure 12-30 Integrated Heat Rejection, AP600 Containment Model; Double Clime Clime Noding Sensitivity Study october 1997 c:\\3221w-12.non.1b-101397
12-42 3,C O
O B
Figure 12-31 Pressure History, AP600 Containment Model; Double Stack Clime Noding Sensitivity Study October 1997 o \\3221w-12.non.ib-101397 i
1243 O
a,e a
i O
\\
Figure 12-32 ' Heat Rejection History, AP600 Containment 1%odel; Double Stack Clime Noding Sensitivity Study October 1997 o:\\3221w.12.non.1b-101397. -
12-44 F
~
8,C O 9
L Figure 12-33 Integrated Heat Rejection, AP600 Containment Model; Double Stack Clime Noding Sensitivity Study October 1997 o:\\3221w-12.non.lb-101397
12 '
p t
a,c.
I..
s O
L A
Figure 12-34 ' Pressure History, AP600 Containment Model; Double Mesh Clime Noding Sensitivity Study.
%,39,7 o:\\3221w-12.non.1b-101397 -
12-46 a,c i
I O
Figure 12-35 Heat Rejection History, AP600 Containment Model; Double Mesh h
Clime Noding Sensitivity Study
- ' I#
o:\\3221w 12.non.1b-101397
12 -
O a,e d
i O
Figure 12-36 Integrated Heat Rejection, AP600 Containment Model; Double Mesh Clime Noding Sensitivity Study octhe im
_ o:\\1221w-12.non.lb-101397