ML19248D713
| ML19248D713 | |
| Person / Time | |
|---|---|
| Issue date: | 07/16/1979 |
| From: | Teh-Chiun Su Office of Nuclear Reactor Regulation |
| To: | Denise R, Hanauer S Office of Nuclear Reactor Regulation |
| References | |
| REF-GTECI-A-39, REF-GTECI-CO, TASK-A-39, TASK-OR NUDOCS 7908170240 | |
| Download: ML19248D713 (30) | |
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UNITED STATES
[ 1)M.]'j NUCLEAR REGULATORY COMMISSION E
WASHINGTON. D. C. 20555 7,=%
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. y JUL 161373 Generic Task flo. A-39 MEMORAtlDUM FOR:
S. H. Hanauer, Director, Unresolved Safety Issues Program, tiRR R. P. Denise, Acting Assistant Director for Reactor Safety, DSS FROM:
T. M. Su, A-39 Task Manager, Containment Systems Branch, DSS
SUBJECT:
SUMMARY
OF MEETING HELD Ott APRIL 4, 1979 WITH REPRESENTATIVES OF THE GENERAL ELECTRIC COMPANY TO DISCUSS SRV METHODOLOGY On April 4,1979, a meeting was held in Bethesda, Maryland with representatives of the General Electric Company.
The purpose of the meeting was to discuss the methodology for predicting bubble phasing during multiple valve discharges for all Mark III containments where the GE designed cross quencher device is used in the safety / relief valve discharge line.
An attendance list and a copy of the meeting handouts are enclosed.
Backaround In April 1978, the General Electric Company submitted an Interim Containment Loads ibport, Mark III Containment (22A4365). Attachment M to the report provides an outline of the methodology for determining multiple safety / relief valves bubble-phasing.
Since then a series of discussions had been held between GE, the staff and their consultants.
Following these discussions, GE had gathered all staff concerns and provided justifications for each concern.
GE, therefore, requested the meeting to discuss these justifications.
Summary 1.
The bubble frequency distribution curve was generated on the basis of 132 data points obtained from tests at reactor pressures ranging from 150 to 1000 psia. Since the wide range of initial testing condition will affect the bubbit frequency distribution, we requested that GE generate a bubble-frequency curve based on initial testing pressure close to rated reactor pressure.
In response to this request, GE presented the results of their study, which was based on selected reactor pressure and initial pool temperature.
This selection criterion reduced the number of data points from the original 132 to 38.
Analyses based on these selected data points resulted in a standard deviation of 1.7 Hz instead of 2.3 Hz as the original curve indicated.
The mean also changes from 8.1 Hz to 8.9 Hz.
Based on the
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20i 7 908170 NO
, JUL 19 373 results of this study, GE proposed a standard deviation of 1.7 Hz and a naan of 8.1 Hz as the design values. Note that the selected mean is based on all data because it results in a higher confidence level.
2.
The results of the study also confirmed that line air volume is the most dominart parameter for determining bubble frequency; the other parameters such as SRV opening time, line air temperature and submergence have no statistically significant effect on bubble frequency.
3.
GE will include the Caorso test results in their final analysis for predictions of bubble phasing during multiple valve actuations.
The preliminary analysis indicates that the current methodology predicts conservativa results when compared with the Caorso data.
4.
The staff and their consultants concluded that the general approach for predicting multiple valve bubble phasing is valid. We will require, however, that GE include the following in the final analysis:
Effect of pool temperature on bubble frequency; a.
b.
Sensitivity study of standard deviation of bubble frequency distribution and its effect on SRV loads; Effect of pool boundaries on bubble frequency; and c.
d.
Structural and equipment response for determining the design case.
T. M. Su, A-39 Task Manager Containment Systems Branch Division of Systems Safety
Enclosures:
As Stated Distribution:
Central File R. Martin NRR Reading D. Ross CSB Reading I&E(3)
H. Denton NRC PDR R. Mattson-Local POR F. Schroeder S. Varoa R. Fraley, ACRS (16)
W. Butler R. DeYoung J. Kudrick D. Vassallo T. Su D. Skovholt R. Denise or7
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Mark III SRV Meeting April 4,1979 Name Orcanization T. J. Su NRC/CSB/ DSS P. Huber MIT/BNL Forrest Hatch GE F. Reuter GE P. Stancavage GE I. Uppal GE L. Sobon GE R. Patel Bechtel R. A. Hill GE P. Moskal Bechtel R. Beck Bechtel C. Tung BNL J. A. Kudrick NRC/CSB/ DSS l00
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BilLTIPLEQUENCHERFEm0DS SlWARY P, P. STNICAVME GBEAL ELECTRIC CGPNP/
CONTAltPBff BEltEERItB PPS-1 4/4/79
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VALIDDATABASE I
FREQUBEY DISTRIBlHION FRW IN - Pl#1T DATA
- FULL SCALE IN TWO BWRS
- WHOLE RNEE OF EXPECTED C0f0lTI006 0
DISTRIBUTION CONFIPPED AT TYPICAL C0f0ITICtB
- PJ!1 PEACTOR PRESSURE
- MODERATE POOL TE'FBATURE
- FIRST ACTUATICt1 0
CAORSO TEST VALIDATES DISTRIBIRI0tl
- FPErt BlCY IS P# 00M
- STR0fE SIGtR S 5 TO 10 &
FPS - 2 4/4/19
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FLUID - STRUCTURE ItHERACTION 8
GLOBALEFFECTSSPALL
- TORUS FDDEL SHOWS t0 FSI IF MIt0R DIA/THIC10ESS LESS EAN 600
- LICENSEE PLN1TS HA'E D/T < 600
- PARK II/III PLAtKS HAVE D/T < 300 0
LOCAL EFFECTS S'ALL
- TP#1SDUCERS ON C0fERETE AND STEEL SHOW SANE FREQUBEIES
- NATUPAL FRE0JENCIES OF LOCAL STRUCTURES FlJCH flIGHER EAN BUBBE FREQUBEIES e
PPS-3 4/4/79 206
CAORSODATA 8
PPESSUPE ATLITUDES BOUNDED BY PPEDICTION
- ENl VALUES PPEDICTED EASURED FIRSTACTUATION
+9.1/-6,5
+4.3/-2,8 SUBSEGET ACTUATIC(i
+15,9/-9,2
+7.2/-4,5
- DESIGil VALVES PPEDICTED (90/90)
EASURED WAX)
FIRSTACTUATION
+12.8/-8,1
+5,0/-4,3 SUBSEQUENTACTUATION
+29,E/-11,6
+8.0/-5,7 8
TIE #0 DISTNICE ATTBlUATION MOPE RAPID THAN PREDICTED 8
BUBBLE FPEQUBlCY IS P# DJi
- CYCLE TO CYCLE
- TEST TO TEST INIEGRAL SECIAL DENSIT/
- VALVE TO VALVE PPS-4
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HJBBLE PFASIf6 0
SPALL IfREPACTION EXPECTED
- BUBBES SEPARATED BY 5 DIA
- IfFLlelCE OftY 10%
- f0 EntCT ON INITIAL CYCES 0
SMALL IfEEPACTION C0tFIRE BY TEST
- FULTIPE VALVE PRESSURE BOUNDED BY SIfEE VALVE PRESSURE
- M0fEICELLO
- CA0RSO
- MULTIPE VALVE WAVEFOR'S MIXED PPS-5 4/4/79
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CONCLUSI0f6 0
DATA BASE IS VALID
- FULL PAfEE OF Ot0lTI0fG
- C0fFIRE AT TYPICAL OP8ATItE STATE
- VERIFIED BY CA0RSO TESTS S
FLUID STRUCTUPE IIRERAClim IS Si@LL
- GLTAL EntCT UNIMPORTATE D/T < 600
- LOCAL EFFECTS NOT @ SERVED 8
CAORSO lESTS C0fFIRM METHODS
- PRESSURE AMPLITUDES
- TIME NO DISTNICE ATIElUATION
- RN00M FRE0lBEIES q,
2O PPS - 6 4/4/79
MULTIPLE QUENCHER METHODS NRC QUESTI0ils I. S. UPPAL CONTAINMENT ENGINEERING APRIL 4, 1979
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QUESTION 1:
DISCUSS THE STOCHASTIC NATURE OF BUBBLE FREQUENCY
RESPONSE
BUBBLE FREQUENCY IS RANDOM DUE TO VARIATIONS IN o
INITIAL CONDITIONS LINE TEMPERATURE WATER LEVEL STEAM CONTENT o
DYflAMIC PROCESS TAYLOR INSTABILITY BUBBLE FORMATION EXPERIMENTAL EVIDENCE SHOWS FREQUEilCY VARIATION EVEfl WITH SIMILAR INITIAL CONDITIONS l\\t it t ISU-1 4l4l79
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SELECT DATA BASE QUESTION 2:
THE D4fA WERE OBTAINED AT REACTOR PRESSURES RANGING FROM 150 TO 1000 PSIA.
HOW DID THIS AFFECT THE OBF OBTAINED?
A SEPARATE OBF INCLUDING THOSE DATA OBTAINED AT FULL REACTOR PRESSURE SHOULD BE GENERATED.
RESPONSE
A SUBSET OF THE DATA BASE WAS SELECTED FROM THE IN-PLANT TESTS WHICH MOST CLOSELY REPRESENTS EXPECTED CONDITIONS FOR AN ALL VALVE ACTUATION EVENT.
THE SELECTION CRITERIA ARE:
FIRST ACTUATION, SINGLE VALVE POOL TEMPERATURE BELOW 110=F REACTOR PRESSURE ABOVE 950 PSIG STANDARD NUMBER OF MEAN DEVIATION TESTS (Hz)
(Hz)
ALL DATA MEETING CRITERIA 38 8.9 1.7 USE TWO ALL DATA 132 8.1 2.3 SIGNIFICANT FIGURES DESIGN USE N/A 8.1 1.7 THERE IS REASONABLE AGREEMENT BETWEEN SELECTED DATA AND ALL DATA.
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o MEAN FREQUENCY OF DATA MEETING CRITERIA IS WITHIN TEN PERCENT OF MEAN FREQUENCY OF ALL DATA.
MEAN FREQUENCY (8.1 Hz) USED IS BASED ON ALL DATA BECAUSE 132 TESTS GIVE HIGHER CONFIDENCE.
o STANDARD DEVIATION OF 1.7 Hz IS SELECTED FOR DESIGN USE 1.7 Hz IS LESS THAN THE STANDARD DEVIATION BASED ON ALL DATA AND HENCE CONSERVATIVE 1.7 Hz IS BASED ON TEST DATA WITH FULL REACTOR PRESSURE AND OTHER CONDITIONS THAT ARE TYPICAL OF BWR PLANTS
[\\J ISU-3 4/4/79
FREQUENCY DEPENDENCE QUESTION 3:
WAS THE QBF OBTAINED UNDER CONDITIONS OF CONSTANT AIR LINE VOLUME, VALVE OPENING TIMES, SRV LINE LENGTH AND HYDRAULIC RESISTANCE, PIPE TEMPERATURE ETC.?
SEPARATE CREDIT IS TAKEN FOR THE POSSIBLE MITIGATING EFFECTS OF SOME OF THESE VARIABLES:
IT IS, THEREFORE, IMPORTANT TO ESTABLISH THAT THEIR INFLUENCE NOT ALREADY IMPLICIT IN THE QBF.
RESPONSE
THE FREQUENCY DISTRIBUTION WAS OBTAINED FROM TWO IN-PLANT TESTS WITH COMPARABLE CONDITIONS DATA MEETING PARAMETER PLANT A PLANT B CRITERIA 5
LINE AIR VOLUME (FT )
50 47 47-50 SUBMERGENCE (FT) 15 13 13-15 POOL TEMPERATURE ("F)85-104 92-169 85-110 VALVE OPENING TIME (MSEC) 150-1000 220-1475 275-1475 REACTOR PRESSURE (PSI) 13-1066 120-1030 950-1066 VARIOUS PARAMETERS WERE INVESTIGATED VIA REGRESSION ANALYSIS FOR THEIR EFFECT ON FREQUENCY.
PRESSURE RISE RATE, VALVE SETPOINT, VALVE OPENING TIME, AND BUBBLE FREQUENCY ARE INDEPENDENT VARIABLES.
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RESULTS OF REGRESSION ANALYSIS o
BUBBLE FREQUENCY IS NOT INFLUENCED BY VALVE OPENING TIME OR REACTOR PRESSURE o
RESULTS SHOW NO TREND REGARDING EFFECT OF OTHER PARAMETERS ON BUBBLE FREQUENCY o
LINE AIR TEMPERATURE WAS FAIRLY CONSTANT 5
o LINE AIR VOLUME WAS (47-50 FT ) CONSTANT EFFECT OF VOLUME NOT IN DATA BASE EFFECT OF VOLUME IS SIGNIFICANT VOLUME IS INCLUDED SEPARATELY 2 ' 'J ISU-5 4/4/79
CA0RSO DATA QUESTION 4:
THE OBF SHOULD BE UPDATED ON THE BASIS OF THE CA0RSO TEST AS S00N AS THESE ARE AVAILABLE.
RESPONSE
o CA0RSO SVA DATA IS IN PRELIMINARY FORM.
ANALYSIS SHOWS CAORSO MEASURED FREQUENCY IS RANDOM.
CA0RSO MEASURED FREQUENCY IS WITHIN RANGE OF PREDICTED FREQUENCIES.
o TWO WAYS TO OBTAIN BUBBLE FREQUENCY
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_ TOTAL DT-BUBBLE OSCILLATION CYCLES loTAL TIME OF CYCLES POWER SPECTRAL DENSITY PLOT (SEE FIGURES 6 & 7) o PSD USED TO DEVELOP CURRENT QBF o
PSD PLOT SHOWS THAT MORE THAN ONE FREQUENCY HAS SIGNIFICANT ENERGY o
PSD FREQUENCY SPREAD IS MUCH LARGER THAN TIME AVERAGED FREQUENCY (TABLE 4)
OVERALL CA0RSO PRESSURE IS A FACTOR OF 2 BELOW MEAN o
PREDICTED
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'/_ \\ 6 ISU-6 4/4/79
o
~IN TABLE 4, PREDICTED MEAN FREQUENCY
= 8.1 x ] h1 = 7.4 Hz o
MEASURED FREQUENCY IS ONE PREDOMINANT FREQUENCY PER TE3T TABLE 4 MEASURED PREDICTED MEAN (Hz)
E.05 7.4 S.D. (Hz) t.41 1.6 LOWER BOUND (Hz) 5.3 4.;
UPPER BOUND (Hz) 6.8 10.9 o
TABLE 3 SHOWS THAT EACH CYCLE HAS ITS OWN FREQUENCY o
CA0RSO MVA MODEL/ DATA COMPARISON UNDERWAY.
THIS COMPARISON WILL SHOW THAT SRVA IS CONSERVATIVE BY A LARGE MARGIN
.LL c\\i ISU-7 4/'/79
FREQUENCY DATA BASE QUESTION 5:
HOW WELL IS THE PROBABILITY DISTRIBUTION KNOWN?
WHAT IS THE DATA BASE?
RESPONSE
THE FREQUENCY PROBABILITY IS BASED ON 132 IN-PLANT QUENCHER TESTS AT TWO LICENSEE FACILITIES.
THESE TESTS PROVIDE THE DATA FOR:
MEAN 8.1 HERTZ STANDARD DEVIATION 1.7 HERTZ UPPER BOUND 12 HERTZ LOWER BOUND 5 HERTZ A CHI - SOUARE TEST SHOWS THAT THE NORMAL DISTRIBUTION IS APPROPRIATE AT 5% LEVEL OF SIGNIFICANCE.
'qL Jib ISU-8 L/4/79
QUESTION 6:
THE POSSIBILITY THAT THE TEST DATA (ESPECIALLY THOSE RELATING TO BUBBLE FREQUENCY) WERE AFFECTED BY FLUID STRUCTURE INTERACTION SHOULD BE ADDRESSED.
RESPONSE
GLOBAL FSI EFFECTS o
APPLIED SRV FORCING FUNCTION TO A COUPLED FLUID STRUCTURE MODEL OF MARK I TORUS o
MODEL SHOWED FOR MINOR TORUS DIAMETER TO SHELL THICKNESS (D/T) RATIO UP TO 600, FSI IS NEGLIGIBLE o
PLANTS A & B 1600.
CONCLUSION OF REFERENCED STUDY IS APPLICABLE o
iiENCE GLOBAL FSI EFFECTS IN PLANTS A & B ARE NEGLIGIBLE LOCAL FSI EFFECTS o
LOCAL STRUCTURAL INFLUENCE IS SHOWN BY TRANSDUCERS AT DIFFEREflT LOCATIONS o
FIGURE 10 SHOWS THE LOCATIONS OF PRESSURE TRANSDUCERS DA 13, 14, 8 16 o
FIGURE 11 SHOWS THAT EACH HAS A BUBBLE FREQUENCY 18 Hz o
THEPEFORE, THIS IS A GENUINE BUBBLE FREQUEilCY, NOT AFFECTED BY LOCAL FSI FREQUENCY DATA FROM TYPICAL PLANTS o
ADDITIONALLY PLANTS A & B'ARE TYPICAL OF MARK II AND III PLANTS.
FSI EFFECTS (NEGLIGIBLE) PRESENT IN A & B WILL ALSO CE PRESENT IN MARK II & III.
(SEE FIGURE 12)
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ISU-9 c
4/4/79
FREQUENCY DEPENDENCE QUESTION 7:
TO WHAT EXTENT IS THE DISTRIBUTION PLAtT -
DOES IT DEPEND ON LINE LENGTH?
LINE TEMPERATURE?
FIRST OR SUBSEQUENT ACTUATION?
RESPONSE
o DESIGN DISTRIBUTION VARIES WITH LINE VOLUME ONLY o
DISTRIBUTION IS BROAD ENOUGH TO ACCOUNT FOR ALL OTHER VARIABLES o
MARK II AND III PLANTS HAVE SAME BASIC GEOMETRY AS FAR AS SRV LOADS ARE CONCERNED.
THIER FREQUENCY IS NOT EXPECTED TO VARY DUE TO PLANT GEOMETRY o
FREQUENCY IS A FUNCTION OF LINE VOLUME o
LINE TEMPERATURE EFFECT IS IMPLICIT IN THE DATA BASE o
CA0RSO SECOND ACTUATION FREQUENC'.' HIGHER THAN FIRST ACTUATION, EARLIER TEST SHOWED THAT FREQUENCY DOES NOT DEPEND ON FIRST OR SUBSEQUENT ACTUATION i.
2U ISU-10 4/4/79
QUESTION 8:
WHAT ARE THE DATA BASES FOR THE PROBABILITY DISTRIBUTIONS OF VALVE SETPOINT AND VALVE OPENING TIME?
RESPONSE
VALVE SETPOINT o
FOR TESTABLE INSTRUMENTATION, SD - 2 PSI APPLIED TO BOTH CROSBY 8 DIKKERS VALVES o
FOR NON-TESTABLE INSTRUMENTATION SD = 8 PSI IS USED BASED ON 24 SHOP TESTS o
FOR TARGET ROCK VALVES SD - 5.9 Psi BASED ON 77 SHOP TESTS.
FIGURE 13 SHOWS THE DISTRIBUTION IS CLOSE TO NORMAL.
VALVE OPENING TIME o
FOR CROSBY VALVES SD =.0092 SEC BASED ON 408 TESTS o
FOR DIKKERS VALVES D =.0097 BASED ON 50 TESTS.
THEREFORE, STANDARD DEVIATION FOR BOTH CROSBY AND DIKKERS IS SPECIFIED AS 0.009 SEC.
o FOR TARGET ROCK VALVES 187 DATA POINTS GAVE SD =.013 SECONDS
"'n 22I ISU-11 4/4/79
AIR VOLUME ON FREQUENCY OUESTION 9:
IT IS PROPOSED THAT THE QBF DISTRIBUTION BE SHIFTED TO ACCOUNT FOR SRV LINE VOLUMES 5
THAT DIFFER FROM THE 50 FT LINES USED TO OBTAIN THE DATA.
THE PROPOSED ADJUSTMENT IS BASED ON A SIMPLISTIC AND POSSIBLY N0i;-
CONSERVATIVE ANALYSIS WHICH NEGLECTS THE KNOWN DEPENDENCE OF BUBBLE PRESSURE ON AIR LINE VOLUME.
A REASSESSMENT OF THIS ASSUMPTION IS REQUIRED.
RESPONSE
THE RELATIONSHIP GOVERNING FREC3NCY AND AIR VOLUME IS, FROM RAYLEIGH'S EQUATION 3
FREQUENCYod / AIR VOLUME THE ENTIRE RELATIONSHIP HAS BEEN EXPERIMENTALLY CONFIRMED IN 1/4-SCALE T-0UENCHER TESTS FOR LINE VOLUMES RANGING 5
5 FROM 24 FT TO 99 FT (SEE FIGURE 14)
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.0 1.5 2.0 PtPE A 4 VOLUME Figure !d Effe : :. 'ipe Air.'clure en Frequency for Ini:ial Pipe and
'.'e: el. Pre s sure :i 2.'
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4/4/79
OUESTION 10:
ONE CENTRAL ASSUMPTION OF THE PROPOSED METHODOLGY IS THAT BUBBLES OSCILLATING SIMULTANEOUSLY IN THE POOL DO NOT INTERACT IN ANY WAY THAT WOULD TEND TO INCREASE THE LOAD AMPLITUDES TO MODIFY THE PHASE DIFFERENCE BETWEEN THE BUBBLE OSCILLATIONS OR TO HARMONIZE THE OSCILLATION FREQUENCIES.
THE BASIS FOR THIS ASSUMPTION IS ONE OF OUR MAIN PRESENT
- CONCERFS,
RESPONSE
o THEORY PREDICTS LITTLE INTERACTION QUENCHERS ARE 14 FEET APART BUBBLE DIAMETERS ARE 2.7 FEET MEAN SPACING IS 5 DIAMETERS EFFECT (1/R) IS 10%
o TESTS SHOW NO INTERACTION MONTICELLO TESTS SHOW SVA SHELL PRESSURES GENERALLY LESS THAN MVA SHELL PRESSURES CA0RSO 2 AND 3 VALVE MVA PRESSURES LESS THAN SVA PRESSURES CA0RSO 4 VALVE MVA PRESSURES ^-20% HIGHER THAN SVA BUT WAVEFORM INDICATES NON-PHASED BUBBLES CA0RSO 8 VALVE MVA PRESSURES 4
'ER THAN SVA AND WAVEFORM INDICATES NON-PHASED udBBLES
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i ISU-14 4/4/79
o MULTIPLE QUENCHER METHOD ALLOWS APPROXIMATE PHASING EXAMPLE IN ATTACHMENT M 3 BUBBLES AT 0.123 SEC AND 9,3 Hz 2 BUBBLES AT 0.128 SEC AND 8.6 Hz
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(, /._ J ISU-15 4/4/79
22AJ. 365 Rev. 2 MA-3
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Valve No.
IVOT (sec)
Valve No.
IVOT (sec)
^;c7 7
0.C67 13 0.056 1
v.29 3
0.051 la 0.061 0.055 9
0.062 15 0.056
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3 0.0c.
11 0.053 17 0.C57 6
0.035 12 0.057 18 0.071 19 0.069
.:::= :na: 2 :ean value of 0.057 sec ia included in the above nu=be:s.
Adding
,i these es_;e s : the group T calculated in Step 3 and nor=alizing to have the firs: bubble arrive a :ero ti:e results in the following bubble Arrival ti=es:
Arrival Ti=e Arrival Ti=e Arrival Time Valve ';c.
(sec)
Valve No.
(sec)
Valve No.
(sec) 1 0.125 7
L_0.125 3 13 0.243 2
0.236 8
0.238 36 14 0.127 3
- v. 223 i 9
0.120 15 0.243 4
0.2 7 10 0.0 16 0,124 5
LO.122 11 0.246 17 0.215 6
0.225 12 0.116 4 13 0.129 19 0.256
., 2
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.' : ' a w L.. %. L 3 Subs _e irc:uencies for individual quenchers are randomly selec:ed fro: a rando:
l nu ber genera: r ecde using :he, distribution shewn in Figure M2 Typical randa: bubble frequency values for the 19 quenchers are:
Valv e '!c.
Frecuency (Hz)
Valve No.
Frecuency (Hz) 6.56 11 7.22 2
9.77 12 3.39 3
- 9.15 )
13 5.68
_5. 01' 14
- 3.60 5
19.331 15 9.36 o
6.38 16 7.04 7
-Q 17 11.08 5
9.10 13 4 3.6S 9
7.92 19 S.52 10 11.14
- 0!E
For this exa:ple, all lines are :ctsidered as unifor= in leng:5 and fre-quencies are randerly selected frc one Quenener Subble Frequene (QSF) aistricu:ic: curve (Figure M2 -). In :his ex:=ple, mean = 3.23 H: and
= '.30 H:...i:n nanunifor: line leng-hs, Subsec:ica M3.2.1 is used :o deve. p unique QSF distribution curves frc= which a frequency is randc=1y g
seiec:ea :ar eacn _,ine.
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ISU-16 4/4/79 s
EFFECT OF LINE ON BUBBLE ARRIVAL TIME QUESTION 11:
AT PRESENT NO CREDIT IS TAKEN FOR POSSIBLE CHANGES IN BUBBLE ARRIVAL TIME DUE TO DIFFERENCES IN SRV LINE LENGTH OR HYDRAULIC RESISTANCE.
THESE FACTORS COULD, HOWEVER, TEND TO NEGATE THE FAVORABLE EFFECT OF DIFFERENT VALUE SETPOINTS.
THEY SHOULD BE ADDRESSED,
RESPONSE
o LINE AIR VOLUME AFFECTS BUBBLE ARRIVAL TIME SOMEWHAT BY CHANGING THE AIR AND WATER CLEARING TIMES 5
o FOR EXAMPLE, AN INCREASE IN AIR VOLUME FROM 57 FT 5
TO 88 FT CAUSES A DELAY OF 56 MSEC IN AIR CLEARING TIME o
IN INDIVIDUAL PLANTS, AIR VOLUME USUALLY LIES WITHIN 25%
o RESULT OF INCLUDING LINE VOLUME FOR A TYPICAL PLANT 5
5 (57 FT 88 FT )
THE AVERAGE FOURIER SPECTRA REMAINED ESSENTIALLY UNCHANGED (FIGURES 15-20)
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ISU-17 s
4/4l79
FORCING FUNCTION SELECTION QUESTION 12:
DISCUSS IN GREATER DETAIL HOW A FREQUENCY DEPENDENT " BOUNDING" FORCING FUNCTION IS DEDUCED FROM THE COMPUTED 59 MONTE CARLO SIMULATIONS.
RESPONSE
o THE FORCING FUNCTION IS BOUNDING IN THE SENSE THAT 59 TRIALS GIVE 95% CONFIDENCE THAT THE PEAK BOUNDS 95%
OF ALL EXPECTED RESULTS.
FEWER TRIALS WILL GIVE LESS CONFIDENCE o
SIGNIFICANT FREQUENCY RANGE IS DIVIDED INTO 3 FREQUENCY AND LARGEST SPECTRAL VALUE WITHIN EACH FREQUENCY INTERVAL IS SELECTED FOR DETERMINATION OF EQUIPMENT RESPONSE o
ADDITIONAL CONFIDENCE IN THE BOUNDING CHARACTERISTIC 0F THE FORCING FUNCTION IS PROVIDED BY:
HIGHEST BUBBLE PRESSURE GIVEN BY ANY DISCHARGE LINE IS USED FOR ALL DISCHARGE LINES.
THE MAXIMUM DESIGN BUBBLE IS EXTREMELY CONSERVATIVE.
THE PREDICTED BUBBLE PRESSURE FOR CA0RSO SVA IS 15.1/-8.9 PSI AS COMPARED TO MEASURED MAXIMUM PEAK BUBBLE PRESSURE OF 5.0/-4.5 PSI.
THE DISTANCE ATTENUATION OF GESSAR/DFFR BOUNDS CA0RSO DISTANCE ATTENUATION
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15U-13 4/4/79
GESSAR/DFFR TIME ATTENUATI0t' BOUNDS TIME ATTENUATION OBSERVED AT CA0RSO (SEE FIGURE 21) o FIGURE 21 ALSO SHOWS THAT CA0RSO DATA IS BOUNDED BY PREDICTIONS BY A LARGE MARGIN o
FOR LINEAR SYSTEMS, HIGHEST INPUT FOR EACH FREQUENCY GIVES HIGHEST OUTPUT
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ISU-19 2
4/4/79
CONFIRMATORY WORK QUESTION 13:
IT IS OUR OPINION THAT COMPARISONS BETWEEN PREDl'TIONS 3ASED ON THIS METHODOLGY AND MVA IN-PLANT LOAD DATA ALREADY AVAILABLE AND TO BE OBTAINED FROM THE CA0RSO TESTS IS AN ESSENTIAL PART OF THE REVIEW PROCESS.
BOUNDING FORCING FUNCTION PREDICTIONS FOR DISCHARGE CONDITIONS CORRESPONDING PRECISELY TO THOSE ACTUALLY TESTED (TWO, THREE, FOUR AND EIGHT VALVE DISCHARGES AT CAORSO, ALL MULTIPLE VALVE TESTS AT E,1UNSBUTTEL) SHOULD BE GENERATED AND COMPARED WITH THE IN-PLANT LOAL DATA.
IT IS RECOGNIZED THAT THE IN-PLANT DATA CONSISTS OF DISCRETE PRESSURE MEASUREMENTS A BEST ESTIMATE OF THE INTEGRATED LOAD MUST NEVERTHELESS BE OBTAINED.
WE EMPHASIZE THE NEED FOR COMPARISONS BETWEEN TEST DATA AND PREDICTIONS BASED ON THE PROBALISTIC PROCEDURE AS APPLIED TO DISCHARGE CONDITIONS IDENTICAL TO THOSE TESTED.
RESPONSE
o A QUICK LOOK INDICATES THAT CA0RSO MVA DATA IS BOUNDED BY PREDIClIONS BY A LARGE MARGIN o
MODEL/ DATA COMPARISON UNDERWAY
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