ML20203M617
| ML20203M617 | |
| Person / Time | |
|---|---|
| Site: | 05200003 |
| Issue date: | 02/27/1998 |
| From: | WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | |
| Shared Package | |
| ML19317C951 | List: |
| References | |
| NUDOCS 9803090151 | |
| Download: ML20203M617 (55) | |
Text
_
WESTINGHOUSE NON-PROPRIETARY b
ADS Discharge investigation IRWST Hydrodynamic Global Analysis
@ Westinghouse Electric,1998-
[BR28su!!888jga
__- _ -_ ~
s -
LIST OF FIGURES Figure Page 2.1 1 AP600 Passive Core Cooling System 5 2.2 1 VAPORE Plant Arrangement 21 2.2 2 ADS Loop Fuit Scale Prototype 22 2.2-3 Location of Sensors on Discharge Piping and in Quench Tank 23 Elevation View 3.2 1 Pressure Time History for Test 330 29 3.2 2 Power Spectrum Density for Test 330 30 3.2 3 Respanse Spectrum for Test 330 (10 - 30 Seconds) 31 3.2-4 R : ponse Spectrum for Test 330 (10 - 15 Seconds) 32 3.2 5 Response Spectra for Test 330 (10 15 and 10.2 to 10.8 Seconds) 33 3.2 6 Pressure Time History and Response Spectrum for Test 330 34
- Subinterval 10.2 to 10.8 Seconds 3.2-7 Pressure Time History for Test 930 35 328 Power Spectrum Density for Test 930 _
36 3.2 9 Response Spectra for Test 930 (20 - 40 and 26.2 to 27.2 Seconds) 37 3.2 10 Pressure Time History and Response Spectrum for Test 930 38
- Subinterval 26.2 to 27.2 Seconds 4.1-1 Test Tank Finite Element Model 40 4.1 2 Test Tank Fundamental Modes- 41 4.2-1 Test 330 Measured vs: Predicted Wall Pressures Time Histories 47 4.2 2 Test 330 Measured vs. Predicted Wall Pressure Response Spectra 48 4.2-3 Test 930 Measured vs. Predicted Wall Pressures Time Histones 49 4.2-4 Test 930 Measured vs. Predicted Wall Pressure Response Spectra 50 ADS Discharge Investigation & 1RWST Hydrodynamic Global Analysis 11 cI' -4 b
g .-
LIST OF TABLES Table Page 2.2 1 VAPORE Phase A Test Matrix 18 2.2 2 VAPORE Phase 81 Test Matrix 19 2.2-3 VAPORE Test Results Peak to Peak Pressure (Bar) 20 4.2 1 Test Prediction Comparison Test 330 45 4.2 2 Test Prediction Comparison Test 930 46
't ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 111 ::+! -' -
_ . - . - _ _ _ _ _ - - - __s
I
1.0 INTRODUCTION
This report desenbes the development of forcing functions to be considered in the design of the AP600 structures, systems and components. The AP600 structural design is based on the hydrodynamic analyses of the IRWST in which a pressure forcing function is applied at the surfaces of sr hencal bubbles which represent the two spargers. The selection of the forcing functions and the analyses of fluid r.ructure interaction effects in the test tank are described herein. The report covers the following topics:
..- Evaluation of ADS tests and the AP600 systems to identify ADS tests or portions of tests that bound the sparger discharge conditions for the AP600
. Selection of source forcing function. Two forcing functions are used in the IRWST -
hydrodynamic analyses. The two tune histories are pressure measurements for short durations measured at an instrument close tc ao sparger dunng two of the tests, The two forcing functions are characterized by different power spectral density shapes and frequency content
.- Structural analyses of the test tank. Modal analyses were performed to determine the -
test tank frequencies. Time history analyses were performed using pressure time histories measured close to the sparger. Pressure response time histories and their power spectral densities were compared against t' s measured values at the walls and demonstrated reasonable agreement with some conervative overprediction due to the fluid structure interaction. Use of the time histones measured close to the spargers 1 was shown to be conservative.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis "u .:M
t
- 2.0 SELECTION OF ADS TEST DATA FOR EVALUATION OF AP600 AUTOMATIC DEPRESSURIZATION This section provides a desenption of the AP600 Automatic Depressurization System (ADS),
and provides the basis for the selection of test data to be used in the evaluation of IRWST hydrodynamic loads that result from operation of the ADS.
2.1 AP600 Automatic Depressurization System Description The AP600 employs automatic depressurization to mitigate loss-of coolant accident events.
The Automatic Depressunzation System (ADS)is a subsystem of the reactor coolant system (RCS) and acts in conjunction with the passive core cooling system (PXS) to provide a controlled depressunzation of the RCS and permit gravity injection of the vanous safety injection tanks including the high pressure core makeup tarins (CMTs), nitrogen-pressurized accumulatior tanks, and the low pressure in-containment refueling water storage tank (IRWST). Figure 2.1-1 provides a simplified sketch of the ADS valves and spargers and depicts the RCS and PXS piping, valves and components.
The ADS valves are designed to operate in four distinct stages. The first stage ADS valves are actuated n a low CMT water level, which is indicative of a significant loss of coolant. The first stage ADS valves are smaller and are slow-opening valves. They function to initiate the blowdown transient and minimize the air-cleanng loads in the IRWST that result from ADS operation. Because they are smaller valves, they provide a controlled initial stage of depressunzation. They reduce the pressure in the RCS to approximately 1200 psig. The second and third stage ADS valves are larger, and open on a time delay after ADS first stage actuation. They are slow-opening valves, and provide a significant blowdown mass flow rate into the IRWST. They operate to reduce the pressure in the RCS to less than 100 r ,ig. The final stage of A'DS is accomplished by the fourth stage ADS valves that are connected to the RCS hot legs and discharge directly to the RCS loop comoartment. They operate to reduce the RCS pressure to allow gravity injection from the IRWST.
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 2 4 , _ _ _ _ . _ _ _ _ _ _ _ _ . _ ___
.e .-
7
' For stages 1,2, and 3, ene,h valve stage consists of two lines, each line containing two valves in series that are both normally closed. Fach line is arranged with an isolation gate valve, in senes with (tnd upstream of) a globe isolation valve. The upstream ADS valves (in each of the three stages) are designated ADS isolation valves, and are cequenced to open before the downstream valves. The downstream ADS valves are designated ADS control valves, and are sequenced to open after the upstream isolation valves are fully open. With this arrangement, the blowdown is controllod by the downstream valve, thus the term ADS control valve. The upstream isolation valves will typically open with no flow. However, both the upstream isolation valves and the downstream contrul valves are designed to open against full RCS
- pressure, temperature, and resultant blowdown flow rates. The ADS valves are described in SSAR Subsection 5.4.6.
To minimize steam leakage dunng normal power operation, the piping to each set of two valves in senes connected to the pressunzer is arranged to provide a cold water seat at the -
inlet of the valve .
The first. secondcand third stage valves are located on the pressunzer safety and relief valve (PSARV) module clustered into two groups. Each group has one pair of valves for each stage. 3 The two groups are on different elevations and are separated by a steel plate. Each group of ADS valves discharge into a piping header that connects to a sparger located in the IRWST.
Each sparger is submerged in the in-containment refueling water storage tank. Each sparger has four branch arms inclined downward. The sparger arms are submerged below the normal water level in the in-containment refueling water storage tank. The spargers are described in
'SSAR subsection 6.3.2.2.6. The spargers are designed to distribute steam into the in-containment refueling water storage tank water, thereby promoting more effective steam condensation.
o ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 3 mu ./"-
. . . . . . = .
2.1.2 ADS Operation Operation of the ADS valves connected to the pressurizer results in steam and water being discharged to the IRWST. ADS operation in response to a loss of coolant accident occurs when the core makeup tank water levelis reduced to the low level Jetpoint. For such an event, the RCS pressure is reduced prior to ADS actuation due to the loss of coolant accident.
Upon ADS actuation, two first stage ADS paths are opened. The blowdown is controlled by operation of the 4-inch ADS control valves. The second and third stage valves open on time delays following the first stage actuation signal. Operation of the ADS valves following a loss -
of coolant accident is modeled in the SSAR Chapter 15 accident analyses.
The ADS is designed to minimize the possibility that inadvertent operation of the ADS valves can occur. Although spunous ADS can not result from a single failure, thi most probable inadvertent ADS event is a spunous inadvertent ADS signal generated by a spunous low CMT water level signal. This would result in the opening of two first stage ADS flow paths with the initial RCS pressure at system operating pressure.
Another more limiting case has been identified for the purposes of bounding the hydrod,namic loads associated with ADS operation. The spurious opening of a single second stage flow path is considered. Although this is a non-mechanistic failure, i.e. there is no credible event that leads to the opening of two second stage valves (in the same flow path) with the RCS at full operating pressure, such an event would be bounding when compared to the spurious opening of a first stage valve at full system pressure, or the opening of a second stage flow path dunng a design basis event (with the first stage ADS valves previously open).
AOS Disenarge Investigation & IRWST Hydrodynamic Global Analysts i .- -- -
= a e ..
8' l-1 Atr. H' S l As ( *. I i
(' 84 d 1)7, 82 J-1, I
]I.# $
'~'
e e ,f a f Ast4Mt f A l
(
/'3 i'
6 t e ut t.
_ _ _ . ~ - . - . . - ~ ~ --I CAwit ,
COR[ M Ah! Ui'
- .1 T At4K (1 (F */)
' PA9ct us
., ;I; ,. s
( )
~~
PRESSURtZER U" ?)
e s ,,, - -
ee4 i pie
)
- k. # 4:n tal iP W'i l 2 I H : _ . _ . _ _ . _ k %. -
l sue 6 As _.
( e 4Al' Afd I JL
,'I'g
, ,i,,
o M s-m St sul' J L, > ()
{}
A D'; g, pg g gg SIAL [ 4 ii N 2) '
~~
r49e,9s
( i ( #1 7)
' ' l[ l PouPS l s ,__s "7 N. P PJ /
1 1 P l
j g j L 4 ---%v,
_ _ . . _ _ _ _ _ . _ _ _ - _ _ . _ - - - - - - .- -- - (g ] -
___--.7.---- _
~
'n' ,
/
ovi oweri
,,,9,
,, , ui,,- ,d - O of 2)
- t. < A<l ll
--+-grHty HlH j :
f4l AC IOff VI *i';l I
( ,/
Figure 2.1-1 AP600 Passive Core Cooling System ADS Discharge investigation & IRWST Hydrodynamic Global Analysis L.___.--______ - . - .
2.2 Testing Perfotiaed to Characterize ADS Blowdown An in depth experimental and analytical effort was conducted to define the design loads on the IRWST structures as well as to demonstrate the performance of system components for predicted operating conditions. The ADS test program was conducted at the VAPORE facility at the Casaccia Center for Energy Research near Rome, Italy. Figure 2.21 is a schematic of the ADS test facility. The ADS test program was conducted as part of a joint technical cooperation between Westinghouse, ENEA, and SOPREN. The AP600 ADS test consisted of two phases: Phases A and B.-
The objective of Phase A testing (Reference [1]) was to evaluate the hydraulic performance of the sparger under various steam flow rates and to measure the pressure pulses resulting from :.
- the discharge of steam into the test quench tank.
The objective of Phase B testing was to evaluate the performance of the ADS system. A full-scale prototype of the ADS valve and piping package (Figure 2.2 2) and sparger (Figure 2.2 3) were used at the VAPORE facility. The ADS Phase B test was a full-sized simulation of one of the two AP600 pressurizer flow paths from upstrearn of the ADS valves to the sparger and was intended to duplicate the operational conditions of the AP600 ADS valves and sparger.-
Phase B tests were divided into two parts, B1 and 82. The overall objective for the ADS Phase B1 tests (Reference (2)) was to simulate the AP600 thermal- hydraulic performance of the ADS following any design basis event and to generate experimental data for validation of the safety analysis computer codes used in support of obtaining design certification for the AP600.
The spe:ific objectives of Phase B1 tests were to:
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 6 m it Lr"
. Collect thermal-hydraulic performance data with both single phase steam and two-phase steam water fiow to support the development and venfication of the analytical models of the ADS to be used ir, safety analyses.
3 Venfy the design and proper operation of the ADS sparger with prototypical two-phase mass flow rates and fluid qualities.
.a
. Obtain quench tank pressure data as input to the IRWST structural design over the full range of expected single-phase steam and two-phase flow rates.
. Simulate AP600 plant piping and ADS valves to charactenze the flow conditions that will occur during a full flow ADS operation.
E g The overall objective for the ADS Phase B2 tests was to assess and demonstrate the operability of the ADS valves. This assessment provided input to the development of the functional requirements for the ADS valves.
In particular, the test Jjectives of the B2 portion of the ADS test were to:
. Collect valve operability and thermal-hydraulic performance data with both single-phase steam and wo-phase steam / water flow to characterize the performances of selected prototypic ADS valves.
Measure the valve stem forces required to open and close the ADS valves at prototypic blowdown conditions.
The two phases should be viewed as two steps of the same activity During Phase A, the objective was to venfy the sparger design and give the preliminary definition of the dynamic loads on the IRWST pool. Phase B was set up to evaluate the ADS loop capabihty and to refine and complete the information gathered dunng the first phase.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 7 -
4 2.2.1 Methodology fnr Evaluation of the ADS Test Data The VAPORE test cases to be used in the IRWST structural analysis are selected as follows.
- Definition of the AP600 operating .ange for the ADS discharge conditions.
s
. Definition of tts bounding test cases to envelope the expected operating conditions
. Definition of the time frSme dunng which prototypic blowdosn conditions exist at the
\ spargei.
1 In Reference (2), the operating range has been defined with regards to mass flow rate and quality. The companson of the test conditions with the expected AP600 operating range, in terms of mt 's flow rate and quality, provides e first check to determ . e if an expenmental test is repre' .ative of the anticipated plant conditions. In addition, the pressure amplitudes at the VAPORE pool walls were stron0ly dependent on the mass flow rate denvative. Therefore, the mass flow rate denvative is also used to evaluate the app!icability of the test data to the AP600.
E in the VAPORE facility, fast opening valves were used to obtair. the required mass flow rates.
However, the first parts of all the expenmental tests (except as discussed later) are charactenzed by very high volumetne flow rate derivatives. The volumetne flow rate denvative impacts the water cleannglair cleanng and the steam bubble formation phases (this is the idealized steam bubble's growth). The net mass flow rate affects the pressure field and also causes significant drag forces on the submerged componer ts. The water / air cleanng and the bubble growth phases for a given expenmenta' *.2 ,,iould not be considered unless the mass flow rate denvative is inside the anticipated range for the AP600 ADS blowdown.
Er ADS Discharge in etig6 tion & IRWST a Hydrooynamic G6. col Analysis 6 -H '
y
[ .nwe M
O '
The most censervative expenmental tests to be used for the IRWST structural analysis are therefore chosen on the basis of both the mass flow rate vs. quality and the mass flow rate denvative.
2.2.2 Analysis of the ADS Experimental Tests The VAPORE expenmental tests were chosen in order to cover the expected AP600 operating conditions. The following section discusses the most significant VAPORE test results and how those tests are representative of the expected AP600 performances. -
ADS Phase A Testina The Phase A tests summanzed in Table 2.21 were dxplicitly performed to gather preliminary, conservativa evaluations of the pressure peaks at the tank walls. The tests were characterized by varying flow rates and quench tank levels and temperature to determine the influence of
'hese parameters on the discharge forcing functions. The fluid blowdown was limited to steam only, since it was considered the most limiting discharge condition with respect to the pressure pulse at the IRWST walls.
The test matnx was init. ally set up to cover the ADS expected operating conditions in terms of flow rate, Several test cases were performed to charactenze the steam blowdown from different combination of valve stages, It should be noted that the maximum valve flow areas used in the test were higher than the AP600 valve areas, resulting in flow rate conditions well beyond that cxpected for the plant.
The following gen 1kral observations can be made about ADS blowdown tests conducted during ADS Phase A Test Program:
AOS Discharge investigation & IRWST Hydrodynataic Global Analysis 9 :nu .--y
- Sparger induced loads in the quench tank dunng initial air cleanng with discharge flow area equivalent to tne second stage opening and opening time of about 20 seconds will not be the limiting case (i.e. the air cleanng transient for valve opening times in the order of several seconds is gradual, this is different from the opening of a safety relief valve with opening time of a few milliseconds).
The pressure pulses measured throughout the quench tank were within the expected (6 0. t bar) even for the most limiting blowdown test.
The pressure pulsen have dominant onergy in the (40 70 Hz) frequency band e Pressure pulse amplitude decreases with increasing quench tank water temperature and increases with increasing water height above the sparger.
Quench tank water was strongly mixed by operation of the sparger. The sparger induced circul9 tion was upward and toward the tank sioes. This is expected due to the downward slant of the sparger arms and due to the location ef the holes in the sparger arms. l e
The sparger induced mixing resulted in virtually uniform heat up of the tank water (The sparger during Phase A was very close to the pool bottom).
- The discharge of steam into the saturated watar caused significant perturbation of the water surface: At the high discharge flow rates, a small amount of water was sp ed out over the side of the quench tank in a penodic circular wave like fashion.
- Sparger operation was aNvays smooth with no evidence of water hammer or chugging" oue to low flow steam rate.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 10 -i ~ -
A cetailed evaluation of the Phase A test data using the entena discussed in Section 2 2.1 determined that the Phase A test data is overly conservative wd* t sect to both mass flow rate and the mass flow denvati.e. Although the Phase A test is U3efulin providing insights with regard to the observatioris noted above, tne 164t data is r.ot used in the IRWST structural analysis B
cv ADS Phase B1 Tests Phase B1 test matnx included both steam only and two phase blowdown tests With respect to Phase A, the following major changes were made:
E
- A prototypical ADS loop was installed dowr stream of the pressunzer.
- The sparger was moved 8.5 ft higher in the test tank. The height of water above the spargeris the same as in the AP600.
Pressure instrumentation was maintained in the same location in the test tank. Thus their location relative to the sparger are different from the Phase A tests As in the Phase A tests, blowdown was not directly controlled by the ADS valves (Reference (2]) The Phase B1 test niatnx is reported in Table 2.2 2. The following is a summary, taken from Reference (2]. of the observations directly related to the ADS package performance:
The tests provided thermal hyoraulic performance data for the simt. lated ADS flow path
, over a wide range of quasi steady state flow rates, including:
Single phtse steam flow at flow rates up to 390 lb/s at > 98% quality Two phase flow at flow rates from 260 to 965 lb/s and 2% to 29% quality at the ADS package inlet.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 11 - -;
s -
l l .
. The tests closely matched the anticipated AP600 ADS operating envelope flow rates and fluid quahties.
- Choked flow occurred at more than ene point in the ADS flow path simultaneously and included:
At the s pen ADS valves dunng some operating modes (e.g., Stage 1 only operation).
At the sparger arm inlet from the sparger body and at the arm holes.
- Sparger operation was smooth with both single and two phase fluid and the resultant pressure peaks appear to be within the expected magnitudes.
The sparger arm geometry created strong mixing currents in the quench tank dunng the blowdown when the tank was subcooled. Ho'vever, complete mixing to the bottom of the quench tank did not occur, as evidenced by quench tank temperature measurements.
e Blowdown in tne fully heated quench tank expelled a significant amount of water from the tank.
- The pressure pulses meksured in the quench tank when the water was fully heated were significantly reduced, as compared to blowdown in cold water.
The air / water cleanng loads were not dominant. However, for tests charactenzed by blowdown initiation rates several times faster than actual plant values, the initial phase -
of the steam blowdown was dominant. .
ADS Discharge Investigation & IRWST Hydroc: 3amic Global Analysis 12 -
J -
.o I
l No significant pressure oscillations (chugging) were observed, although small negative pressures occurred in the sparger and discharge line when the flow was qut;kly terminated and back flowing of the sparger occurred.
The following is a discussion of the Phase B tests.
Senes 100 Senes 100 includes test cases A04110, A041120, A038130 and A039140. These tests are characterized by pure steam blowdown. Each test, as reported in Table 2.2 2, simulated a different combination of ADS valves open.
Test 110 is charectenzed by the first stage valve fully open with an initial pressuie of -2500 psia. The mass flow rate and pressure peaks at the tank walls are the lowest of the senes.
Test case 140 (Stages 1,2 & 3 open,1600 psi) bounds test 120 (Stages 1 & 2 open.1600 psi)
& 130 (1 & 3 open,1200 psi) both in terms of steam flow rate and initial pressunzer pressure. 1 Test 140 mass flow rate ranges from about 250 down to 60 lb/s, and the peak pressure pulses are larger, or at leas' qual to those obtained from the other tests of the same series, Reference [2].
The first phase of the blowdown transient, for senes 100 tests, cannot be considered representative Of the actual plant conditions due to the valve fast opening times and large air cleanng volumes. Also a large part of the steady b!nwdown phase is not representative of the
, AP600 performance due to the supterheated steam conditions at the sparger outlet. This is evident in test 140 that is charactenzed by a rapid depres sunzation. The VAPORE pipes are first heated up by then high pressure and temperature steam while dunng depressunzation phase the pipes provide additional heat to the steam causing a superheating of about 15'F at the sparger exit (see Reference (2]). The superheating requires a larger heat t'ansfer area to quench the steam and hence results in an additional steam bubble growth with consequent pressure soikes
, ADS Disenarge Investigation & IRWST Hydrodynamic Global Analysis 13 .m u er M l
I
Since the AP600 is charactenzed by a much slower plant depressunzation initiation and a short pure steam blowdown phase before the two phase low quality fluid flow takes place, the superheated conditions shown in the VAPORE facility are not representative of the AP600 behavior.
Based on the above, only the time frame 20 seconds and 30 seconds of test 140 can be considered representative of a large pure steam blowdown range, Senes 300
. Senes 300 test cases, see Table 2.2 2, are characterized by two-phase Howdown conditions.
The two-phase blowdown covers mass flow rate up to %5 lbm/s. While this is about 25% less than the maximum expected mass flow rate for the AP600 plant (conservatively evaluated about 1200 lb/s), these tests cover a large part of the AP600 operating range The dependence of the measured pressure peaks on mass flow rate is not strong. Test data indicate that the dynamic pressure pecks are comparable over a large mass flow rate / quality region. Therefore. since the resulting pressure peaks measured in the pool are lower than those obtained dunng pure steam blowdown, it is possible to conclude that the increase of mass flow rate necessary to bound the operating range is not expected to provide more limiting results than the pure steam blowdown cases (e.g., Test 140).
It is important to note that while pressure histones for pura steam blowdown have frequencies in the range of 40-70 Hz, the pressure histones for the two phase blowdown have a frequency content that extends in the range 10 40 Hz.
For the two phase blowdown conditions, Test A004330 (maximum flow larger than 650 lb/s with a quality of 15% during the steady blowdown phase) provides the highest pressure peaks and has frequency content in the range 10-40 Hz. For this t0st, the valves opening time (much faster than AP600 valves opening times) and air cleanng volumes are not representative of the ADS Discharge investigation & IRWST Hpkodynamic Global Analysis 14 -
H -
a o
anticipated plant conditions and therefore the first seconds of test blowdowns are not representative of the AP600 plant performance.
Additional Test Cases Additional test cases were performed subsequent to the completion of Phase B1. These tests are discussed below. These additional cases were blowdowns with puie steam, with the blowdown initiated by opening prototypical ADS valves, s
19sLELQ Test 800 is fully representative of an AP600 plant first stage inadvertent opening since the first stage globe valve of the VAPORE facility is charactenzed by the same opening time of the AP600 first stage ADS valve. Steam flow rate and pressurizer pressure compare well with the RELAP evaluations both for the plant and the facility.
The significant pressure traces at pressure transducers show that the first part of the blowdown transient is not limiting In particular, the slow air cleanng/ water clearing phase produces pressure pulses at the r,parger locan:1(PE 14) and at the VAPORE tank that are less than 50% of the peak values evaluated dunng phase B1 tests (Test 140 & 330)(see Table 2.2 3).
Pressure peaks are reached dunng the valve closure phase at low flow rat 6s.
Senes 900 Senes 900 includes tests 920 and 930 which were performed to charactenze the opening of the second or third stage valves at full pressure. However, due to VAPORE facility limitations.
in order to obtain flow rates comparable to those expected from the AP600 plant, the valve opening times were cceelerated from 70 seconds to 10-12 seconds. The resulting initial i ADS Discharge Investigation & IRWST hydrodynamic Global Analysis 15 :u b. -_
e blowdown transient is more severe than AP600 considenng that the valve opening times were comparable to the water cleannglair cleanng phase (water cleannglair cleanng phase is respectively about 12 and 8 seconds for the first stage and second stage valves first opening respectively).
Based on the abovt, the initial blowdown phase of the senes 900 tests should not be considered for the IRWST structural analysis. However, the post air / water cleanng phase of the test data are within the envelope of the AP600 plant operating range for the opening of a second or third stage ADS valve at full pressure.
Summary of Results The analysis of the ADS Phase A & Phase B tests show that the expenmental tests cover the AP600 expected operating region defined in terms of mass flow rate vs. quality. However, the Phase A tests are over conservative and are not representative of the AP600 expected conditions since the total simulated valve flow area and mass flow rate are more than double that of the AP600 plant.
Dunng Phase B1 severallow quality /high mass ficw rate discharge transients have also been performed. Low quality blowdown mass flow rate pt aks up te about 1000 lb/s (quality in the range 10 20%), in test numbers 330/331/340 While these tests present pressure peaks lower than those related to the steam blowdown, they are charactenzed by a lower frequency spectrum with respect to the t mm only blowdown cases. Test 330 is representative of low quality high mass flow rate conditions and is used as input to the structural analyses.
Additional test cases which are more repr .mentative of the AP600 plant performance were performed withprototypical ADS valves installed Those additional tests are representative of the anticipated plant conditions; in particular Tests 920/930 have been performed to bound the
. high quality steam flow rate conditions charactenstic of the Second/ Third Stage Valve Opening at full pressure. Test 920 is used as input to the structural analyses.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 16 -H -
H
O Test 800,is representative of the initial part of the blowdown transient since the First Stage ADS globe valve tised at the VAPORE facility is charactenzed by same opening time as the AP600 valve. Test 800 has been used to assess the initial part of the blowdown transient both for the first and second ADS valve opening. Test 800 has shown that, as expected, the slow valve opening times produce very low loads during the !nitial blowdown transient.
=_
ADS Cischarge Investigation & IRWST Hydror)ynamic Global Analysis 17 mo ..
~ .
1 Tatde 2.2-t VAPORE Phase A Test Matrix i '
Te t Drurn insti,N Pressurizer Test Drurn Peak Press Descharge Pipe (s) Quench Tank Quench Tank Condit on Pressure Actual Actual Actual Sate Nomenal Level Norrr alLevel Test No Sanulated , (pseg) (pssg) (en#) (ft) (ft) Nodes A1.A2 A3,A4 End of ADS Blowdown 1600 -500 96 82 24.19,15 5,12 90 4 with 1",2". and 3" Stages 2 x 8' Sch 80 open 1 x 3* Sch 160 .
AS.A7,A9 End of ADS Blowdown 1600 -500 96 82 9,12,15 5 180 4 with 1". 2*. and 3'* Stages 2 x 8~ Sch 80 open 1 x 3* Sch 16G
_ AG,A8,A10 End of ADS Blowdown 1600 -500 96 82 9,12,15 5 212 4 with 1". 2**. and 3 Stages 2 x 8~ Sch 80 open 1 x 3 Sch 160 A11 1" Stage Au Clearing & 2500 -2100 5 42 15 5 90 3. 4 Blowdown to 2* Stages 1 x 3 Sch 160 Actuation 1" Stage An Clearing & 2500 -2100 5 42 18 7 180,212 1.3,4 A12.A13 Blowdown to 2" Stages 1 x 3* Sch 160 Actuahon Inadvertent 2" or 3'* Stage 2300 -800 45 7 15 5 90 4 A14 open Instsated Aw Clearing 1 x 8* Sch 80 and Blowdown 1600 -600 51 12 15 5 90,180.212 4 A15.A16,AIT 1" and 2" Stage Bicwdown 1 x 8' Sch 80 1 x 3" Sch 160 A18 A19 1" Stage Aw Clearing & >$00 -2100 5 42 15 5 17),212 2.3 4 Blowdown to 2" Stage 1 x 3 Sch 160 Actuation Nose t) Tests performed wnn dWterent sub emergency fonownng ENENs decesson, due to enceptional operaeme reasons
?) Huns performed with the condnions requeed for Tests A12 & A13
- 3) Indaal (nomraal) pressurizer pressure lower than requwed dt.e to a leah s* the piart> service hne
- 4) Actual Sazes from commercsaty manufactured pipes ADS Discharge Inves!qation & 1RWST '
, u .. -
Hydrodynamec Global Analysis 18 i,.s
A Table 2.2 2: VAPORE Phase 81 Test Matrix ADSi r$ASE B1 TEST MATRIX Test Supply Control Facility Confi0uration Matrix ADS Simulation Tank Valve Flow No Pressure Area 100. SERIES TESTS Saturated steam blowdowns from 110 Stage 1 open 2500 psig N/A top of supply tank; onfices installed; 120 Stages 1 & 2 open 1600 psto N/A cold quench tank temperatures . 130 Stages 1 & 3 open 2 1200 psig N/A .
140 Stages 1. 2 & 3 open i 1600 psia N/A 200. SERIES TESTS Saturated water blowdowns from 210 Stage 1 open 2235 psig 1.4 in'
, bottom of supp!y tarik; 211 Stage 1 open 2235 psig 2.1 in-onfices installed; 212 Stage 1 open 2235 psia 3.5 in' i cold quench tank temperatures 220 Stages 1 & 2 open 1200 psig 3 5 in' 221 Stages 1 & 2 open 2235 psia 3.5 in' 230 Stcoes 1 & 3 open 1'200 psig 3 5 in' 231 Stages 1 & 3 open 2235 psig 3 L in' 240 Stages 1,2 & 3 open 1200 psia 3 5 in' 241 Stages 1.2 & 3 open 500 psia 3.5 in' 242 Stages 1.2 & 3 open 500 psia 7 in' i
250 Stage 2 open 1200 psig 7 in'
- (inadvertent opening) 300 SERIES COLD QUENCH TANK TESTS Saturated water blowdowns from 310 Stages 12 & 3 open 2235 psig 7 0 in' bottom of supply tank; 311 Stages 1.2 & 3 open 1200 psic 3.5 in-no onfices installed 312 Stages 1.2 & 3 open 500 psig 14.0 in' cold quench tank temperatures 330 Stages 1 & 2 open 1800 psig 7 0 in' 331 Stages 1 & 2 open 1200 psig 21 in*
340 Stage 2 open 2235 psig 35 in' (inadvertent opening) __
f 360 SERIES HOT QUENCH TANK TESTS Saturated water bicwdowns from 320 Stages 1.2 & 3 open 2235 psig ' 7 0 in' bottom cf supply tank; 321 Stages 1.2 & 3 open 1200 psig 8 4 in-no onfices installed 322 Stages 1.2 & 3 oper' 500 psig 14 0 in' quench tank temperatures 212' F 350 Stages 1 & 2 open 1800 psig 14 0 in' (100 'C) ,
351 Stages 1 & 2 open 1200psig 21 in' _
ADS Discharge investigation & IRWST Hydrodyriamic Global Analysis 19 . . ' J *
,__.._.__s,
_ _ . . _ , _ _ , ,_m. - _ . . , , _ . , .- _._._,,,s. _.,_..m., y..-,.--_-.,
0 Table 2.2 3: VAPORE Test Resuhs . Peak to Peak Pressure (Bar) b
==
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 20 3n+; . a+
I_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ ,
I Aco m g i m r uT2 4'
lW I
u l
seem supper I
{7 l vAos i th
[~ty M ..
"I y I
I '
l D6ed=9e m ,
14' I
l t______.m.____
_a_
l i
i Ir /N >
12 ...
W 1.1 -l '#
OD steem casemor lg l e
Matsure . .I separasar r "r N' " $**d* '-- 3 I
4
- n. e .
suu l V R 1.1 l steem Header 3* I i
(]-[
~ ~ c_ _ _ _ _ _ _ _ _ _ _ ., sparger I
1r seemned wesw une sparger "sinmweser e support '.j-
/Ddloop
~
_ y({\
'd rg rus -
isoisson cereal -
stM4A1 Figure 2.21: VAPORE Plant Arrangement ADS Discharge inv estigation & IRWST Hydrodynamic Global Analysis 2 '. '- -
l eacmou a f ( , A.ll lill
, I,]
m m ,
m _
I I i 45 37 N D, , -
1h - . - r -
)
s S '!'
/[7w h-p- _
l I _ ro oue.cu
~ TAMK o a M, ,
4 secnow A secnow e e
o FMote PMSSUPMR (SUPM.Y TAMIQ Figure 2.2 2: ADS Loop Full Scale Prototype ADS Discharge investigation & IRWST -
Hydrodynamic Global Analysis 22 -H 3' ' "
=
www.w 4 -.-.-.-.-.-.-.-.-.-.-.-.-.y ir -
\
2-- -
O@@ @9? @ .
o
.. we we we ne. v ww 4- < <
l l
@l@j j 4 w-
- i :
. . sus.
@ ~~
mn f k i !@!@'.
,.m n - . .
l :
igj :
p 'l 6
@: i i di !
I!
! :@l@!
l
! ! ! @! un su n @
non @!@ i !@!
.d
--s ain ; : p. :
s.n n i h]! ] l @l i
! D .'"
un l l l@l ?! i I
Imaximmimilms' - - - -
9
>==we Trarueweer h memename WImm rack O vertenty ahm PE13 from A064 to end of teedng seem ones s m s.14 hAasenrenew Figure 2.2 3: Location of Sensors on Discharge Piping and in Quench Tank Elevation View ADS Disc .a je Investigation & IRWST Hydrodynamic Global Analy=is 23 +i ~
~ _
3,0 SELECTION OF SOURCE FORCING FUNCTION This section describes the development of the hydrodynamic forcing function for automatic depr6ssurization system discharge into the in containment refueling water storage tank.
Hydrodynamic loads, measured in hydraulic tests of the automatic depressurization system sparger in a test tank, are selected for analysis of the IRWST using the source load approach (Reference 3). Analyses of the tests define source pressure loads that are then used in analyses of the in containment refueling water storage tank to give the dynamic responses of the containment internal structures.
- Section 2 desenbes the selection of bounding tests from the series of testa conducted with
, , discharge conditions representative of one sparger for the AP600. The following tests have been selected since they bound, or are representative from the hydrodynsmic point of view, of any expected ADS discharge transient (mass flow rate and enthalpy) and rnoreover, compared to the other cases, result in higher pressure pulse amplitudes in the test tank.
. Test case 330 in the time frame of 15 to 30 seconds represents a two phase blowdown transient. The combination of high raass flow rate (above 650 lb/s) and quality results in pressure histones with Jignificant frequency content below 50 Hz and pressure peaks at the test tank walls comparable to the highest values measured dunng the two phase
! 'owdown tests
. Test case 930 in the time frame of 25 to 50 seconds represents opening of the second or third stage of ADS at full pressure. It is characterized by pure steam flow. Pressure pulse amplitudes are +/ 0.3 bar at the steam bubble and about +/ 3.2 bar at the tank walls.
i -
The pressure traces measured dunng the test discharges were investigated further as desenbed in this section to:
ADS Dir, charge investigation & IRWST Hydrodynamic Global Analysis 24 Mr C "
mm__ _ ._-.._.
. l
~
(1) bound the expected discharge from the automatic depressunzation system:
(2) characterize the pressure wave transmission through the pool water; (3) determine the maximum pressi 1 amplitudes and the frequency content.
The forcing functions defined above were developed for use in structural analyses of the test tank and the IRWST. Frequencies of interest for these tanks are in the range of 10 to 50 hertz. Maximum responses of such structures can be obtained t sing only a short portion of the time history. Part of the investigation of the pressure time histories was therefore to select shorter subintervals from the time histories that would give similar maximum responses when applied to structures with frequency content in the range of interest as would application of the ,
full time history. For this purpose pressure time histones and power spectrum densities were !
examined at reference sensors, both for the total duration of the discharge transient identified in Section 2 and for shorter duration entical time intervals. These short subintervals were then used as input in structural analyses of both the test tank and the IRWST. ,
3.1 Selection of Measured Test Pressure Location Pressure time histones measured dunng the tests were reviewed to identify the pressure -
transducers to be used for the evalud; ion of Source Strength. The analysis of the pressure amplitudes shows the following differences between the pressure traces at each location for the same test:
l-
. The pressure amplitudes at the same radius and below the sparger arms (PE 13) remain almost constant duting the discharge transient.
I
. The, pressure amplitudes at the pool walls present a different behavior with the amplitude decreesing .with the flew rate. This behavior at the pool walls is physically consistent with the flow rate. After the valves have reached the full open position, the mass flow rate through the valves steadily decreases so the pressure peaks at the pool wall are also expected to decrease.
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 25 mu : -' "
- w- r v.. 2-.--- - , w,-,,-,..-1wi,,,m,m-s- - --- - - or r n .-,----v,-.,- , . , - --my--- * - , -~--,.3--ns, .---r,,- ,.w e wr-p
j The different behavior of the pressure histories near the sparger is due to a strong local disturoance factor that is a function both of the rotational chaotic motions that occur near the source and of the local effects crused by the velocity field and associated forces that decay l 3 -with the fourth power of the distance from the source, 1
i The preasure time history measured below the sparger (PE13) is used as the source forcing fur'ction. This seier, tion is justified by the analyses of the test tank desenbod in ,
. Section 4.0 which show conservative predictions of wall pressures using this source function.
3.2 Selection of Time History Subintervals
?
A systematic approach was used to identify shorter subintervals within the measured pressure i
time histones selected in subsection 3.1, Subintervals of the time history were evaluated for the following parameters:
. Maximum pretsure amplitude, including measured well pressures; e Frequency content as indicated by Power Spectral Density (PSD);
e Amplified Response Spectra (AFRS T) are produced for the whole time history and compared / overlapped to the (AFRS B) associated with the selected subinterval; frequency ;
ranges where the (AFRS B) are significantly lower than the (A FRS-T) are identified and i compared with the predicted frequency charactenstics of the IRWST steel wall and the concrete filled module walls (IRWST boundary walls);
. Simplified models with elastic and frequency characteristics rurssentative of the IRWST structures are used to evaluate the structural effects of the subintervals. Dynamic
! __ responses to additional subintervals are evaluated and compared against responses predicted for the base intervals. Compensons are made in terms of distnbution of i maximum wa'l pressure, displacements and accelerations.
ADS Discharge investigation & IRWST 4
Hydrodynamic Global Analysis 26 mu < W H i-af- = w Pg+-*?+--7='19--:r:" rme*-r4MwT_-'-ffe-- , rcet- e-mey -- -era -e*we- . m zu r5 'r- - r '-- eurTws-w--v7'++pwre' ent-' et 'rT-*'-* e'-*"eD--rw r-mut--T' r-*-rw*w
e The minimum time duration of both base and additionalintervals is selected considenng the frequency characteristics of both the excitation and the structures.
Test 330 Figure 3.21 shows the time history measured during test 004330 (hereinafter simply labelt,d as 330). The strong pressure period is between 10 and 30 sec. The Power Spectral Density Function (PSD) shown in Figure 3.2 2 indicates frequency content around 20 and 40 Hz.
Similar indications are provided in the amplified response spectrum curve of Figure 3.2 3.
Shorter intervals result in response spectra that are practically coincident with those of the longer time history. Response spectra calculated for the interval from 10 to 15 seconds are shown in Figures 3.2 4. Response spectra calculated for the interval from 10.2 to 10.8 seconds are shown in Figures 3.2 5. It can be seen that they are similar to the spectra of Figures 3.2 3. The time intervals of Test 330 govern the low frequency range (below 40 Hz).
The short subintervals result in response spectra that are practically coincident with those of the whole time history. The subinterval from 10.2 10.8 seconds is therefore used to define the source prestdre. Use of this subintervalis conservative since it is within tne higher amplitude portion of 10 to 15 seconds which was identified in Subsection 2.2.2 as overly conservative due to the faster test opening times. Maximum pressure amplitudes are about 30.
percent lower for the more prototypic conditions after 15 seconds. The timt histories and amplified response spectra for this subinterval are shown in Figure 3.2-6.
ADS Discharge Investigation & IRWST Hydrodynamic Global Ana:ysis 27 :nn ).. n
Test 930 Figure 3.2 7 shows the time history meas ured dunng test A069930 (hereinafter simply labeled as 930). The strong pressure period is between 20 and 40 seconds. The Power Spectral Density Function (PSD) shown in Figure 3..: 8 indicates frequency content around 50 and 60
[ Hz.
Response spectra calculated for the interval from 20 to 40 seconds and from 26.2 to 27.2 secon15 are shown in Figurrt 3.2 9 The time intervals of Test 930 govem the high frequency range (between 40 and 60 Hz). The short Jubintervals result in response spectra that are practically coincident with those of the whole time history. The subinterval from 26.2 to 27.2 seconds is therefore used 9 define the source pressure. The time histories and amplified response spectra for this subinterval are shown in Figure 3.210.
i ADS Diacharge Investigation & IRWST Hydrodynamic Global Analysis 28 mH 2' -
.b l
1
":%dy:.
Figure 3.21: Pressure Time Flistory for Test 330 ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 29- 3m 3':*+
t .
b ,
Figure 3.2 2: _ Power Spectrum Densit/ for Test 330 ADS Discharge Investigation & 1RWST Hydrodynamic Global Analysis 30 anst . 3 -
si t
P
4 b
v Figure 3.2 3: Response Spectrum for Test 330 (10 30 Seconds)
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 3' inie 3 .- $$
e b
t Figure 3.2 4: Response Spectrum for Test 330 (1015 Saconds)
ADS Discharge Investigation & 1RWST Hydrodynamic Global Analysis 32 w.e? v . -25
~
b Figure 3.2 5: Response Spectra for Test 330 (1015 and 10.2 to 10.8 Seconds)
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 33 a.67 2 -- "
e
b 1
Figure 3.2 6: Pressure Time History and Response Spectrum for Test 330 (Subinterval 10.2 to 10.8 Seconds)
ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 34 2 nit " . ' >+
)
b Figure 3.2 7: Pressure Time History for Test 930 ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 35 n;n 2.-- ++
K-r E
E
~ ~ -. '
_ .b L .
k- j P 4 r
?
\
l l
w E
u a
a L
Figure 3.2-8: Power Spectrum Density for Te4 930
.._ ADS Discharge liivestigzhon & IRWST Hydrodynamte Glota' Analysis 36 u.i; 3 .9e E
p -
b I
) =-
i Figure 3.2 9; Response Spectra for Test 930 (20-40 and 26.2 27.2 Seconde)
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 37 22:-r ><!H 1
3 Figure 3.210: Pressure Time Histcry and Response Spectrum for Test 930 (Subinterval 26.2 to 27.2 Seconds)
AD& Discharge investigation & IRWST Hydredynamic Global Analysis 38 2nir .u
4.0 STRUCTURAL ANALYSES OF THE TEST TANK 4.1 Mndal Analyses The mathematical model of the test tank consists of a 3D sector finite element model,15 degrees wide, as shown in Figure 4.1-1. Boundary conditions are imposed to model an axisymmetnc behavior. The tank is assumed to be supported at the top and the effect of the surrounding soils is neglected. The model uses STIFF 30 fluid and STIFF 63 structural ANSYS finite elements, that take into account fluid compressibility and fluid structure interaction.
Fundamental modes computed for frequencies below 100 Hz are shown in Figure 4.12.
. The first mode at 26 Hz is the flexural response of the bottom of the tank.
The second mode at 65 Hz involves flexure of the wall as well as the bottom of the tank.
i ADS Discharge Investigation & IRWST
, Hydrodynamic Global Ana'ysis 39 uue cu
b Figure 4.1-1: Test Tank Finite Element Model ADS r,ischarge Investigation & IRWST Hvdrodynrnic Global Analysis 40 u.n >
. +
nMh
1 b
I a
L Figure 4.1-2: Tank Test Fundamental Modes ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 41 n'4?-
' .' ii
4.2 Time' History Analyses Using Pressure Forcing Function Fluid structure interaction analyses were performed with the ANSYS computer code. The mathematical model of the test tank developed for the post test predictions is similar to that used in thJ modal analyses desenbed in Subsection 4.1. Rayleigh damping of 4% is presenbed for the concrete structure, and fluid damping is neglected. Direct step by step time integration is used. The measured discharge pressures for each time interval are imposed as uniform pressures on the idealized spherical surface of the steam water interface and <
pressures transmitted through the water to the tank boundary are calculated.
Pressure time histones induced on the test tank water were analyzed for the two test subintervals selected in Section 3 (Test 330: 10..? - 10.8 seconds and Test 930: 26.2 - 27.2 secc.4ds). Pressure response time histonas were calculated at locations corresponding to pressure sensor locations in the test tank and were compared with the measured time histories, A similar companson is made in terms of pressure response spectra between computed and measured values.
Test 330 Pressure time histones and pressure response spectra computed at entical wall locations for Test 330 are shown in Figures 4.21 and a 2-2 and are compared with the correspoMing test results. Maximum pressures and response spectrum ordinates at key frequencies are shown in Table 4.21. These comparisons show the following indications:
. Comouted wall pressure histories are conservative against measured values.
. Computed wall pressure response spectra are reasonably conservative, especially at frequencie's below 30 Hz and above 40 Hz.
A.
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 42 : r. n .- 4
! In the intermediate frequency range, there is a frequency shift between a measured frequency at 35 Hz and computed frequencies at 26 and 40 Hz. Note that the fundamental frequency of the FEM modelis 26 Hz; the actual frequency may be higher due to the restraining effect of the surrounding soil.
. Maximum pressures are obtained for sensor PE18 and PE19 (peak values of 0.26 and 0.2 bars respectively);
The goveming time intervalis contained between 10 and 12 seconds, including the subinterval of 10.2 10.8 seconds, selected for the source pressure sensor PE13.
Test 930 Pressure time histories and pressure response spoetra computed at entical walllocations for Test 930 are shown in Figures 4.2 3 and 4.2 4 and are compared with the corresponding test results. Maximum pressures and response spectrum ordinates at key frequencies are shown in Table 4 2 2. These compansons show the following indications:
. Computed wall pressure time histones are very conservative.
Computed wail pressure response spectra contain significantly higher peaks at the tank
, characteristic frequ:;ncy of about 64 Hz.
. Maximum pressures are obtained for sensors PE16 and PE15 (peak values of 0.21 and 0.19 bars respectively.
The goveming time intervalis contained between 20 and 30 seconds, including the subinterval at 26.2 27.2 seconds selected for the source pressure sensor PE13.
ADS Discharge Investigation & 1%M:iT Hydrodynamic Global Analysis 43 mie 9:' H 4 _ ______
The comparisons between measured and predicted wall pressures show that the wall pressures are predicted conservatively using the selected subintervals of the pressure tirre histones measured at PE-13. Comparisons of the response spectra show the computed spectra to be conservative relative to the spectra for the measured time histones. This conservatism is partially due to direct use of pressure time histones measured in the tank which include amplification at the natural frequencies of the test tank. Althougn the use of this excitation leads to predict rather conservative results against those measured, they have been selected as input for the IRWST hydrodynamic analpis.
i ADS Disct'arge Investigation & IRWST Hydrodynamic Global Analysis 44 anse o r > 49
, y -
l Table 4.2-1 Test Prediction Comparison - Test 330 PE13 Max Values +0.22/-0.17 U >
5 ADS Discharge investigation & IRWST Hydrodynamic Global Analysis 45 mn , io' w -
Table 4.2 2 Test Prediction Comparison Test 930 PE13 Max Values +0.22/ 0.2 b
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 46 3 n9 e < 3 / ;' > *9
o 1
1-
)
r Figure 4.2-1: Test 330 Msasured vs. Predicted Wall Pressures Time Histories l
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 4 ~1 3 n e, p . , 2.
- o l
r i
c Figurs 4.2 2: Test 330 Measured vs. Predicted Wall Pressure Response Spectra AOS Discharge investigation & IRWST Hydrodynamic Global Analysis 48 uur Ur H
,_., 3 1-l.
A s
I t-a r
Figure 4.2 3: Test 930 Measured vs, Predicted Wall Pressures Time Histories ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 49 m. u . ' ,
- l
t
- b l
l Figure 4.2 4: Test 930 Measured vs. Prod!cted Wall Pressure Response Spectra ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 50 an4e o."
l
4 f ..
1 5.0
SUMMARY
AND CONCLUSIONS Examination of test results related to the structural design of the in containment refueling water storage tank under automatic depressurization system hydrodynamic excitation and the companson with the analytical procedure previously described, lead to the following conclusions %arding the sparger source term de6nition:
The automatic depressurization system discharge into cold water produces the highest
. hydrodynamic pressures. The tests at higher water temperatures produce significantly lower pressures.
Two pressure time histories, characterized by different shapes and frequency content, can be selected as representative of the sparger discharge pressures; they are assumed as acting on a spherical bubble centered on the sparger centertine and enveloping the ords of the sparger arms; The application of such time histories as forcing functions to an analytic.al model, simulating the fluid structure, interaction effects in the test tank, has been found to predict the measured tank wall pressures, for the two selected reference time intervals.
The two defined sparger source term pressure time histones can be used as forcing functions for global hydrodynamic analyses of the in-containment refueling water storage tank by developing a comprehensive fluid structure finite element model and reproducing the test tank mesh pattom in the sparger region.
ADS Discharge Investigation & IRWST Hydrodynamic Global Analysis 51 33tse , )<ri n i
e
l o 9
- ? .
i
6.0 REFERENCES
(1) WCAP 13981 Rev. O "AP600 Automatic Depressurization System Phase A Test Data Report."
(2) WCAP 14324 Rev. O " Final Data Report For ADS Phase 81 Tests"
- {3) Fitch, J.R. et al., " Source Load Approach to Evaluate Boiling Water Reactor Pressure Suppression Containment Loads", Proceedings Eighth SMIRT, Paper J 7/3,1985.
t e
r ADS Discharge Investigation & IRWST Hydrodynami Global Analysis 52 331se < 9:',29 b} __ ___;