ML20155A688
| ML20155A688 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 09/30/1993 |
| From: | Mintz S, Torbeck J GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML20138L443 | List: |
| References | |
| DRF-T23-00711, DRF-T23-711, GENE-637-022-08, GENE-637-022-0893, GENE-637-22-8, GENE-637-22-893, NUDOCS 9810290220 | |
| Download: ML20155A688 (42) | |
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GENucl:ar En:rgy Gemared Elatene Conereny iis Cmww Avenna. San Jose, CA 95123 GENE 637 022-0893 DRF T23-00711 CLASS !!
SEMEMBER 1993 Quad Cities Nuclear Power Station Units 1 and 2 Evaluation of the Minimum Post-LOCA Heat Removal Requirements To Assure Adequate NPSH For the Core Spray and LPCUContainment Cooling Pumps Prepared by: IM S. Miniz U
Plant Performance Analysis Projects Approve
[*
_,.4 E. Torbeck Project Manager, ECCS & Containment Analysis Projects 1
I 9810290220 981023 PDR ADOCK 05000254 P
GENE-637-022-0893 IMPORTANT NOTICE REGARDING
~
CONTENTS OF THIS REPORT The only undertakings of the General Electric Company (GE) respecting information in this document are contained in the contract between Commonwealt Edison Company (CECO) and GE, as identified in Purchase Order Number 341715 YY-59, as amended to the date of transmittal of this document, and nothing contained in this document shall be construed as changing the contract.
The use of this information by anyone other than CECO, or for any purpose other than that for which it is intended, is not authorized; and with respect to any i
unauthorized use, GE makes no representation or warranty, express or implied, and assumes no liability as to the completeness, accuracy or usefulness of the l
information contained in this document, or that its use may not infringe privately owned rights, l
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GENE-637-022-0893 ABSTRACT This report provides the results of an evaluation of the Quad Cities containment response during a design basis loss-of-coolant accident (DBA-LOCA).
The containment response was evaluated for a range of heat removal values for the residual heat removal (RHR) system heat axchanger.
The results of the Quad Cities containment pressure and temperature response analysis described in this report were used to determine the trend of peak suppression pool temperature with RHR heat exchanger performance and to determine the minimum acceptable heat removal capability of the Quad Cities RHR heat exchanger which will assure there is adequate NPSH available for the core spray and LPCI/ Containment i
Coolkng pumps which take suction from the suppression pool.
t
-iii-
GENE-637-022-0893 TABLE OF CONTENTS fiL19.
ABSTRACT iii
1.0 DESCRIPTION
OF THE WORKSCOPE 1
2.0 CONCLUSION
2 3.0 CESIGN ASSUMPTIONS AND ENGINEERING JUDGEMENT 4
4.0 INPUT DOCUMENTATION 8
5.0 REGULATORY REQUIREMENTS 8
6.0 LIMITATIONS OF APPLICABILITY 8
7.0 CALCULATIONS'AND COMPUTER CODES 10 8.0 QA/ RECORDS 12
9.0 REFERENCES
12 10.0 APPENDICES 26 A.
CORE HEAT DATA A-1 B.
MINIMUM WETWELL PRESSURES FOR B-1 EVALUATION OF REQUIRED NPSH C
USAR BENCHMARK ANALYSIS C-1 4
-iv-
l GENE 637-022-0893 l
l
1.0 DESCRIPTION
OF WORKSCOPE The purpose of this evaluation is to determine the minimum acceptable heat l
removal capability of the Quad Cities Residual Heat Removal (RHR) Systems heat exchanger (HX) which will assure there is adequate NPSH available for the core spray and LPCI/ Containment Cooling pumps which take suction from the suppression pool during a design basis loss-of-coolant accident (DBA-LOCA).
The DBA-LOCA for Quad Cities is the postulated double-ended guillotine break of I
a recirculation suction line. The results in this report also show the sensitivity of the peak suppression pool temperature following a DBA-LOCA to the RHR HX heat removal capability.
The results of this evaluation can be used to support an operability assessment of the RHR HX.
The workscope of this report involves analysis of the primary containment performance following a DBA-LOCA for Quad Cities.
Specifically, analysis of the containment long-term pressure and temperature response following the DBA-LOCA was performed.
Long-term is defined here as beginning at 600 seconds into the event which is when containment cooling is initiated and' proceeding through the time of the peak suppression pool temperature.
This analysis uses the GE SHEX computer code and current standard assumptions for containment cooling analysis including use of the ANS 5.1 decay heat model.
The analysis is performed for'a range of RHR heat exchanger (HX) heat transfer coefficient,
'K', values.
The analysis results are compared against containment conditions (pool temperature and wetwell airspace pressure) required for adequate NPSH for the LPCI/ Containment Cooling pumps and Core Spray pumps.
The suppression pool temperature and wetwell airspace pressure required for adequate NPSH were provided by Commonwealth Edison Company (Ceco) in Reference 1.
An additional analysis was performed to bench mark the SHEX code with the original Quad Cities USAR analysis.
The benchmark analysis used key inputs and assumptions used originally to analyze Case e of USAR Table 6.2.3.
These included May Witt decay heat (Reference 2), an initial suppression pool temperature of 90*F, no feedwater addition and a RHR HX heat removal rate of l
l 1
GENE-637-022-0893 t
84.5 million Btu /hr (corresponding to a' suppression pool temperature-to-service water temperature difference of 85'F).
The benchmark analysis is provided in Appendix C of this report.
l l
2.
RESULTS/ CONCLUSION 2.1
SUMMARY
OF RESULTS:
l Pressure and Temoerature Containment Resoonse Deoendence on K t
l:
The results of the Quad Cities containment pressure and temperature response
- analysis for a DBA-LOCA are summarized in Table 1.
Table 1 gives the peak suppression pool temperature and the wetwell pressure at the time of the peak suppression pool temperature vs RHR HX K with I and 2 LPCI/ Containment Cooling pumps.
Table 1 also gives the RHR HX heat removal at the time of the peak suppression pool temperature.
This is the maximum heat load for each case.
Figures 1, 2 and-3 show the containment pressure and temperature response for Case 3 which is typical of the' response for all cases.
Figure 4 compares curves of the peak suppression pool temperature vs K for 1 LPC1/ Containment Cooling pump and 2 LPCI/ Containment Cooling pumps.
The peak suppression pool temperature with 2 LPCI/ Containment Cooling pumps are slightly higher than the temperatures with 1 LPCI/ Containment Cooling pump due to a higher pump heat.
NPSH E/aluation Figure 5 compares curves of the calculated wetwell pressure at the time of the peak suppression pool temperature vs. peak suppression pool temperature for 1 LPC1/ Containment Cooling pump and for 2 LPCI/ Containment Cooling pumps.
The wetwell pressures with 1 LPCI/ Containment Cooling pump are approximately 2 psi less than the wetwell pressures with 2 LPCI/ Containment Cooling pumps for a given suppression pool temperature.
This is attributed mainly to a lower total
GENE-637 022-0893 flow rate through the RHR heat exchanger which produces a lower spray temperature.
There is also a minor effect due to the lower pump heat added to the containment spray with one LPCI/ Containment Cooling pump.
These two effects together result in lower drywell and wetwell airspace temperatures with 1 LPC1/ Containment Cooling Pump and consequently lower pressures in the~wetwell
. airspace.
The results in Figures 6 and 7 compare the calculated wetwell pressure and pool temperature at the time of the peak pool temperature with the values of required wetwell pressure for adequate NPSH reported in Reference 1 for 1 and 2 LPCI/ Containment Cooling pumps respectively.
The required wetwell pressures shown in Figures 6 and 7 which were provided by Ceco in Reference 1 are for the LPCI/ Containment Cooling pumps.
However, Reference 1 noted that the wetwell pressure requirements for the LPCI/ Containment Cooling pumps are more limiting than the wetwell pressure requirements for the core spray pumps.
Table 2 which was developed from the data in Figures 6 and 7 shows the maximum allowable pump flow as a function of HX K value for 1 and 2 LPCI pumps.
Table i
2 shows that for pump flow rates less than 5300 gpm for one LPCI/ Containment Cooling Pump and for pump flow rates less than 10600 gpm for 2 LPCI/ Containment Cooling pumps, the predicted wetwell pressures will be greater than the required wetwell pressures for adequate NPSH for the range of RHR HX K values evaluated (100 to 500 Btu /sec *F).
For flow rates greater than approximately 5300 gpm per pump (for 1 or 2 pumps), the results of the current analysis predicts wetwell pressures which are less than the required wetwell pressure.
Benchmark Analysis The results of the analysis performed to bench mark the current analysis with the analysis documented in the USAR are provided in Appendix C.
The analysis in App;ndix C used key input assumptions which are consis, tent with the inputs used in the analysis for Case e of USAR Table 6.2-3.
This included the use of May Witt decay heat (Reference 2), an initial suppression pool temperature of GENE-637-022-0893 90'F, no feedwater addition and a RHR HX heat removal rate of 84.5 million Btus/hr (referenced to a suppression pool temperature-to-service water temperature difference of 85'F).
The peak suppression pool temperature obtained with the GE SHEX, code is 181'F which is 4*F higher than the value of 177'F given in USAR Table 6.2-3.
This confirms that SHEX predicts peak suppression pool temperatures for Quad Cities which are higher than those,
predicted in the USAR for the same input conditions.
2.2 CONCLUSION
S The sensitivity of pool temperature on the RHR HX K value is given in Figure 4.
Based on Figure 4, a minimum RHR HX K value of 277 Btu /'F-sec will assure that the calculated peak suppression pool temperature following a DBA-LOCA will not exceed the maximum value of 177'F given in Table 6.2-3 of the USAR.
Based on the results shown in Figures 6, 7 and 8 it was determined that for LPC1/ Containment Cooling pump flow rates less than 5300 gpm per pump, there will be adequate NPSH for the core spray pump and the LPCI/ Containment Cooling pumps which take suction from the suppression pool for the full range of K values analyzed here.
Ceco should consider uncertainties in the measured pump flow when determining if adequate NPSH is available.
3.0 DESIGN ASSUMPTIONS AND ENGINEERING JUDGEMENTS Input assumptions were used which maintain the overall conservatism in'the NPSH evaluation by maximizing the suppression pool temperature and minimizing the wetwell pressure.
The following key input assumptions were used in performing the Quad Cities containment LOCA pressure and temperature response analysis:
1.
The reactor is assumed to be operating at 102% of the rated thermal power.
(The inputs used to model the reactor vessel are the same as used in the Dresden containment analysis described in Reference 4 This is GENE,637-022-0893 l
since Dresden and Quad Cities'have the same vessel design (BWR 3, 251" diameter vessel).
The difference in rated power level between Dresden and Quad Cities was accounted for in the analysis inputs.)
2.
Vessel blowdown flowrates are based on the Homogeneous Equilibrium Model (Reference 5).
3.
The core decay heat is based on ANSI /ANS-5.1-1979 decay heat (Reference 1).
4.
Feedwater flow into the RPV continues until all the feedwater above 180*F is injected into the vessel, i
l (The feedwater inputs used for the analysis were developed originally for the Dresden containment analysis of Reference 4.
Per Reference 1, there are no major differences in the feedwater systems between the two plants.
Therefore the use of the Dresden FW system inputs will not have a significant impact on the results.)
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S.
Thermodynamic equilibrium exists between the liquids and gases in the drywell.
Mechanistic heat and mass transfer between the suppression pool and the suppression chamber airspace was modeled.
6.
To minimize the containment pressure for this NPSH evaluation it is.
assumed that there is only partial heat transfer to the fluids in the-drywell from the liquid flow from the break which does not flash. To model partial heat transfer in the analysis, a fraction of the non-flashing liquid break flow is assumed to be held up in the drywell and to be fully mixed with the drywell fluids before flowing to the suppression pool.
Thermal equilibrium conditions are imposed between this l
held up liquid and the fluids in the drywell as described in Assumption No. 5 above.
The liquid not held up is assumed to flow directly to the suppression pool without heat transfer to the drywell fluids.
For the 4 l
l GENE-637 022-0893 analysis it is assumed that only 26% of the non-flashing liquid flow from the break is held up in the drywell airspace.
Because the liquid flow j
from the break is at a higher temperature than the drywell fluid, this minimizes the drywell temperature and consequently minimizes the drywell and wetwell pressure.
l 7.
The vent system flow to the suppression pool. consists of a homogeneous l
mixture of the fluid in the drywell.
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8.
The initial suppression pool volume is at the minimum Technical Specification (T/S) limit to maximize the calculated suppression pool temperature.
9.
The initial drywell and wetwell pressure were at the minimum expected operating values to minimize the containment pressure used to evaluate available NPSH.
l 10.
The maximum operating value of the drywell temperature of 150*F and a relative humidity of 100% were used to minimize the initial non-condensible gas content and minimize the long-term containment l
pressure for the NPSH evaluation.
11.
The initial suppression pool temperature is at the maximum T/S value to maximize the calculated suppression pool temperature.
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12.
Consistent with the NPSH evaluation in USAR Section 6.3, containment t
sprays are available to cool the containment.
Once initiated at 600 seconds it is assumed that containment sprays are operated continuously with no throttling of the LPC1/ Containment Cooling pumps.
13.
Passive heat sinks in the drywell, suppression chamber airspace and suppression pool are conservatively neglected to maximize the suppression pool temperature.
)
4.
GENE-437-022-0893 14.
All Core Spray and LPCI/ Containment Cooling system pumps have 100% of their horsepower rating converted to a pump heat input which is added either to the RPV liquid or suppression pool water.
15.
The LPC1/ Containment Cooling pump flow rates used in the analysis are based on the nominal rated values: 5000 gpm with one pump and 10000 gpm with two pumps,
- 16. Heat transfer from the primary containment to the reactor building is conservatively neglected.
17.
Although a containment atmospheric leakage rate of 5% per day was used to determine the available NPSH in USAR Section 6.3.3.2.9, containment leakage is not included in this current analysis.
Including containment leakage has no impact on the peak suppression pool temperature, but will slightly reduce the calculated containment pressure. A leakage rate of 5%
per day is considered to be unrealistically large since the T/S limit for allowable leakage is 1% per day.
Use of the leakage rate of 1% per day would result in less than a 0.1 psi reduction in the pressures calculated l
in the analysis.
This effect is negligible considering all other input conditions have been chosen at their limiting values to minimize containment pressure and the assumption of only 20% holdup of the non-flashing liquid flow from the break in the drywell (see assumption no.
6).
Therefore containment atmospheric leakage was not included in the analysis.
e i
t l
GENE-637-022-0893 4.0 INPUT DOCUMENTATION 4.1 Inputs The initial conditions and key input parameters used in the long-term containment pressure and temperature analysis are provided in Table 3.
These are based on the current Quad Cities containment data which were confirmed by Ceco in Reference 3.
Appendix A provides the core decay heat based on ANS 5.1 used in the analysis.
Appendix B provides the values of required wetwell pressure versus suppression pool temperature for the LPCI/ Containment Cooling pumps which was provided by.
CECO in Reference 3.
4.2 Industry Codes and Standards The core decay heat used in the analysis (see Attachment A) is based on ANSI /ANS-5.1-1979 decay heat (Reference 6).
5.0 REGULATORY REQUIREMENTS The analysis were performed per Regulatory Guide 1.49.
Pertinent sections of the USAR for this report include USAR Section 6.2 and 6.3.
6.0 LIMITATIONS OF APPLICABILITY The results of the proposed analysis can be used to support an operability assessment of the RHR heat exchanger.
However, Ceco should confirm that adequate NPSH is the limiting concern in determining the minimum RHR heat exchanger requirements for Quad Cities.
Examples of other issues which may be l
[
1 GENE-637-022-0893 affected by RHR heat exchanger performance and are not addressed in this report include:
temperature limits for pump seals, local pool temperature limits specified in NUREG-0783, reactor shutdown cooling times and dynamic loads defined during the Mark 1 Containment Long Term Program (LTP).
In addition, if Ceco chooses to update the Quad Cities USAR based on this analysis it should be noted that the results o.f the analysis in this report are not sufficient by themselves to provide a complete basis for updating the USAR.
l The #halysis results contain the information required to revise the NPSH evaluation in USAR Section 6.3.
However, to update the long-term containment analysis in USAR Section 6.2 this analysis will need to be performed again with assumptions which maximize the long-term containment pressu e response.
- Also, additional analyses may be required to revise the USAR analysis results for the different containment cooling configurations described in USAR Section 6.2.1.3.3.
Finally, the USAR should be reviewed to ensure that all appropriate USAR sections are revised where necessary, e.g. Section 6.2 (LOCA long-term containment cooling, NUREG 0783 and Mark I containment LTP), Section 6.3 (NPSH j
evaluation) and Section 5.4.7 (reactor shutdown cooling).
I The results of the analysis described in this report are based on the inputs described in Section 4.0.
Any changes to these inputs should be ruiewed to determine the impact on the results and conclusions reported here.
Finally, the results presented in this report, specifically the results in Table 2 and Figures 6 and 7 are based on the values of required wetwell l
pressure for adequate NPSH given in Reference 1 for the LPCI/ Containment Cooling pump flow rates.
Uncertainties in the pump flow rate should be considered by Ceco in applying these results to determine the maximum LPC1/ Containment Cooling pump flow rate or Core Spray pump flow rate which maintains an adequate NPSH.
i
.g.
l
GENE.-637-022-0893 7.0 CALCULATIONS AND COMPUTER CODES 7.1 Calculation Record The calculations used this report are contained in the GE design record file DRF T23-00711.
7.2 Model Description The GE computer code SHEX was used to perform the analysis of the containment pressure and temperature response.
The SHEX code has been validated in conformance with the requirements of the GE Engineering Operational Procedures (EOPs).
In addition, a benchmark analysis to validate the code for a plant specific application to Quad Cities was performed.
This analysis is included in Appendix C to this report.
SHEX uses coupled reactor pressure vessel and containment model, based on the Reference 7 and Reference 8 models, to calculate the transient response of the containment during the LOCA.
This model performs fluid mass and energy balances on the reactor primary system and the suppression pool, and calculates the reactor vessel wr.ter level, the reactor vessel pressure, the pressure and temperature in the drywell and suppression chamber airspace and the bulk suppression pool temperature.
The various modes of operation of all important auxiliary systems, such as SRV's, the MSIV's, ECCS, the RHR system and feedwater are modeled.
The model can simulate actions based on system setpoints, automatic actions and operator-initiated actions.
7.3 Analysis Approach The long-term pressure and temperature response was analy. zed for the DBA-LOCA which is identified in the USAR as an instantaneous double-ended break of a recirculation suction line.
Sensitivity analyses were performed for a range of GENE.637-022-0893 i
K values assuming 1 and 2 LPCI/ Containment Cooling pumps are available. As
~
described in Section 3, these sensitivity analyses used input assumptions which maximized the suppression pool temperature and minimized the containment pressure response.
The purpose of these analyses were to determine the trend of peak suppression pool temperature and wetwell pressure at the time of the peak suppression pool temperature with K.
i Note, that for this analysis the K value is independent of the LPCI/ Containment Cooling pump flow rate.
In actuality, the K value is a function of several parameters including the LPCI/ Containment Cooling pump flow rate with a higher
- pump flow' rate resulting in a higher value of K.
Therefore the results of the analysis at the lower K values are more representative of operation with 1 LPC1/ Containment Cooling pump.
Similarly, the results of the analysis with the higher values of K are more representative of operation with 2 LPCI/ Containment Cooling pumps.
This should be considered in the operability assessment to be performed by CECO.
The core spray flow rate, number of RHR loops and number of LPCI/ Containment Cooling pumps corresponding to USAR Cases c & e of USAR Table 6.2.3 were used d
for the analysis.
Continuous containment spray operation (starting at 600 seconds) with no throttling was assumed for the analysis to minimize containment pressure. Nominal values of the containment spray flow rate for 1 LPCI/ Containment Cooling pump (5,000) gpm and 2 LPCI/ Containment Cooling pumps (10,000 gpm) were used.
1 Six values of K were selected for each of the two LPCI/ Containment Cooling pump configur'tions deicribed above, for a total of 12 cases.
Table 4 summarizes a
the LPCl/ Containment Cooling pump and core spray pump parameters for each case.
I The USAR benchmark analysis is described in Appendix C.
4 1
i 1
i GENE-637-022-0893 8.
Q/A REC 0F.DS All work performed to produce this document and supporting background information is contained in the GE design record file DRF T23 00711.
9.0 References 1)
Letter, C. A. Moerke (CECO) to J. E. Torbeck, " Minimum Wetwell Pressure l
Required for Evaluation of the Minimum Post-LOCA Heat Removal Requirements for Quad Cities Units 1 and 2," August 5, 1993, (CHRON# 0121389) 2)
NED0-10625, " Power Generation in a BWR Following Normal Shutdown or Loss-Coolant Accident Conditions," March 1973.
3)
Letter, C. A. Moerke (Ceco) to J. E. Torbeck, " Verification of Key Containment Parameters to be used in Evaluation of the Minimum Post-LOCA Heat Removal Requirements for Quad Cities Units 1 and 2," August 4, 1993, (CHRON# 0121386).
4)
GENE-770-26-1092, "Dresden Nuclear Power Station, Units 2 and 3, LPCI/ Containment Cooling System Evaluation," November 1992.
t 5)
NE00-21052," Maximum Discharge of Liquid-Vapor Mixtures from Vessels,"
General Electric Company, September 1975.
6)
" Decay Heat Power in Light Water Reactors," ANSI /ANS 5.1 - 1979, Approved by American National Standards Institute, August 29, 1979.
7)
NEDM-10320,"The GE Pressure Suppression Containment System Analytical Model," March 1971.
8)
NEDO-20533,"The General Electric Mark III Pressure Suppression Containment System Analytical Model," June 1974.
s 9 i
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GENE-637-022-0893 l
t a
Table 1 -
Peak Suppression Pool Temperature and Wetwell Pressure at time of Peak Suppression Pool Temperature vs RHR H/. Heat Transfer l
Coefficient - K Max.
RHR No. of PEAK.
Heat K
K Cooling TEMP.
PRES.
Load **
l CASE (Btu /Sec 'F)
Pumps
(*F)
(PSIA)
(million Btu /hr) 1
^
1 150 1
208 24.0 61.0 l
2 200 1
191 20.1 69.1 3
250 1
180 16.2 76.5 l
4 300 1
172 17.1 83.2 5
400 1
164 15.8 99.4 6
500 1
160 15.2 117.0 i
l 7
150 2
210 26.5 62.1 8
200 2
192 22.1 69.8 9
250 2
180 19.9 76.5 l
- 10 300 2
173 18.7 84.2 1
11 400 2
164 17.3 100.8 12 500 2
160 16.5 117.0
- Wetwell (WW) pressures shown here are at the time of the peak suppression pool temperature.
- The maximum heat load occurs at the time of the peak suppression pool.
l 1
j.
l t
=
t i
GENE-637-022-0893 Table 2 - Maximum Allowable LPCI/ Containment Cooing Pump Flow Rate for Adequate NPSH.vs. RHR HX K.
l l
Max.
l RHR No. of Allowable HX LPCI/ Containment LPCI/ Containment K
Cooling Cooling Pump Flow (Btu /Sec *F)
Pumos (anni l
150 1
5300 i
200 1
5300 250 1
5400 300 1
5400 400 1
5300 500 1
5300 l
150 2
10800 200 2
10800 i
250 2
10800 E
300 2
10800 400 2
10800 500 2
10600 l
l l
l 0
i
?
i ' l l
GENE-637-022-0893 l
l Table 3 - Input Parameters Used for Containment Analysis Value Used in Parameter Qnita Analysis Core Therc31 Power MWt 2578 Vessel Dome Pressure psia 1020 3
- Drywell Free ( Airspace) Volume ft 158236 (irtcluding vent system) 1 Initial Suppression Chamber Free (Airspace) Volume 3
Low Water Level (LWL) ft 119963 Initial Suppression Pool volume 3
Min. Water Level ft 111500 Initial Drywell Pressure psig 0.0 Initial Drywell Temperature
'F 150 Initial Drywell Relative Humidity 100 i
l Initial Suppression Chamber Pressure psig 0.0 Initial Suppression Chamber Airspace Temperature
'F 95 initial Suppression Chamber Airspace 100 Relative Humidity Initial Suppression Pool Temperature
'T 95 No. of Downtomers 96 2
Total Downcomes Flow Area ft 301.6 Initial Downcomer Submergence (LWL) ft 3.21 i
l l
l GENE-637-022-0893 l
Table 3 - Input Parameters O'id for Containment Analysis s
Value Used in Parameter Mnill Analysis Downcomer I.D.
ft-2.00 Vent System Flow Path Loss Coefficient (includes' exit loss) 5.17 Sapp. Chamber (Torus) Major Radius ft 54.50 Suppm Chamber (Torus) Minor Radius ft 15.00 Suppression Pool Surface Area ft 9971.4 2
in contact with suppression chamber air space)
Suppression Chamber-to-Orywell Vacuum Breaker Opening Diff. Press.
- full open psid 0.5 l
Supp. Chamber-to-Drywell Vacuum 2
Breaker Flow Area ft 18.85 (Total)
Supp. Chamber-to-Drywell Vacuum Breaker Flow Loss Coefficient' (including exit loss) 3.47 LPCI/ Containment Cool.ng Heat Exchanger K in Containment Cooling Mode Btu /s *F See Table 2 LPC!/Containmer.t Cooling Service Water Temperature
- F 95 l
, l
-. =.
. ~.
GENE-637-022-0893 Table 3 - Input Parameter Used for Containment Analysis Value Used in Parameter yn111 Analysis
~
LPC1/ Containment Cooling Pump Heat (per pump) hp 600 Core Spray Pump Heat (per pump)
'hp 850 Time Tor Operator to turn on LPCI/ Containment Cooling System in Containment Cooling mode (after LOCA signal) sec 600 Feedwater Addition (to RPV after start of event; mass and energy)
Feedwater Mass Enthalpy
- Node **
11hml (8tu/lbm) 1 34658 308.0 2
96419 289.2 3
145651 268.7 4
91600 219.8 5
65072 188.4 Includes sensible heat in the feedwater system pipe metal.
Feedwater mass and energy data combined to fit into 5 nodes for use in the analysis.
1 1
l l l
l GENE-637-022-0893 Table 4 - Flow Rates Used in' Containment Response Analysis Core RHR Containment RHR Spray RHR Pumps Spray HX X Flow Qig loops Per Loon Flow (com)
(BTU /*F-sec)
Rate (com) l 1
1 1
5,000 150 4,500 2
1 1
5,000 200 4,500 3
1 1
5,000 250 4,500 4
1 1
5,000 300 4,500 l
5 1
1 5,000 400 4,500 6
1 1
5,000 550 4,500 7
1 2
10,000 150 4,500 8
1 2
10,000 200 4,500 9
1 2
10,000 250 4,500 l
10 1
2 10,000 300 4,500 11 1
2 10,000 400 4,500 12 1
2 10,000 500 4,500 l
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t FIGURE 4 i
3ER<
300_, "EM3ERATURE VS RF R
-ElT EXC-IRNGER COETICIENT 1 & 2 LPC1/ENTfilbt1ENT COELING PltPS 210 _fllK SLPPRESSION POOL TEMPERflTlRE (f) r P
M
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a T
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?
N 190 :
s 2
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180 :
i i
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m 150 10 0 200 300 400 500 K BRl/f-SEC)
-o-1 LPC1/COMmNfNT COOLING PltP
-*-2 LPC1/CONmMfNT COOLING Pllf'S
[
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t I
i i IGilRL 5 t
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WETWELL PRESSURE VS POOL TEMPERFlTURE i
1 & 2 LPCl/CONTRItt1ENT CODLING P11PS SIEX 27 _ETWR L PRESSURE IPSIA)
L t
/
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/
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23
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SIFPRESSION PO[L T&FERATIE IF)
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iIGURE 6 p>_.,n, L. O pSSU T,m y S a 0 0 "
r vl0 T R T U F'
~
L m
- M E ' & !l ' 8 & g g s y,,
cen MWLL PRrs99g gp3gg, 35 i
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LAIED MEgygll PR SSURE I
n, IIGilRL 7 WE7 ELL.
'RESSURE VS P00m "E*3ERF"URE CfLDJLflTED VS REQUIRED HETHELL PRESSURE f'OR fYJEOURTE NPSH 12 LPCI/ CONT. COOL PLtPSI HETHELL PRESSLRE IPSIH1 35
,12 C 2
~
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' '11000 m
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'10600 g
1 08 25 h
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,ewee==?Y r'
i 15 i
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,,,,,,,,220 10
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8
-e - CALEULATED WETWELL PRESSURE
GENE-637-022-0893 I
~
10.0 APPENDICES i
A.
CORE HEAT DATA l
B.
MINIMUM WETWELL PRESSURES FOR EVALUATION OF REQUIRED NPSH C
USAR BENCHMARK ANALYSIS l
1 l
i
=
GENE-637-022-0893 l
APPENDIX A CORE HEAT DATA Table A.1 provides the core heat (Btu /sec) and integrated core heat (8tu) used in the analysis of Section 7.0.
The core heat includes decay heat, metal-water reaction energy, fission power and fuel relaxation energy.
The core decay heat used for the analysis was obtained from Reference A.I.
This reference provides the shutdown power considering delayed neutron induced fis'sions, actinide decay heat and the fission production decay (including effects of delayed neutrons) based on the ANSI /ANS 5.1 decay heat model (Reference A.2) assuming an exposure l
of 25.7 GWD/st.
The core heat in Table A.1 is normalized to the initial core l
thermal power of 2561 mwt.
TABLE A.1 - CORE HEAT l
Time (sec)
Core Heat
- l 0.0 1.006 l
1.0
.5634 4.0
.5319 l
10.
.3479 20.
.1092 40.
.0563 60.
.04050 80.
.0385 120.
.0363 120.**
.0303 200.
.0274 400.
.0241 600.
.0221 1000.
.0196 2000.
.0160 4000.
.0127 6000.
.0112 8000.
.0103 10000.
.00972 14400.
.00928 18000.
.00881 20000.
.00859 28800.
.00788 36000.
.00748 l
60000.
.00658
- Core Heat (normalized to the initial core thermal power of 2561 mwt)
- decay heat + fission power + fuel relaxation energy + metal-water reaction energy
- Metal water reaction heat is assumed to end at 120 seconds.
A-1 l
GENE-637-022-0893
REFERENCES:
A.1 GE Design Specification 23A6938, " Decay Heat Requirements,"
August 1991.
\\
l A.2 " Decay Heat Power in Light Water Reactors," ANSI /ANS 5.1 - 1979, Approved by American National Standards Institute, August 29, 1979.
2 a
I l
i l
i i
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- M GENE-637-022-0893 APPENDIX B MINIMUM WETWELL PRESSURES FOR EVALUATION OF REQUIRED NPSH
\\
)
i 4
4 W
4 1
L -
4 7
4 B-1
.=._
1 Calculatios No. NED M-MSD 59 Rev. 0 Quad Cities ECCS NPSH - Minimum Required WetwellPressure a
Since both the RHR ana Core Spray pumps have similar elevanons and NPSHR curves. th Core Spray pumps are bounded in thir analysia by the RHR pumps due to the difference in suction losses To determine the frictional losses at any one or two punty flow. the quadratic reis between head loss and flow establishes the foRowmg:
head losa. - head loss x(nowyflow )2 (3)
Therefore. the nuction losses for the flows to be analyzed are:
One Pump Suction i Two Pump Sucuan Flow (spm) Losses (th! Flow (spm) Losses (ft) 4.500 436 9.000 6.28 5,000
$38 10,000 7.75 6,000 7.75 12,000 l 11.16 Table 1 Calenlations 3
ne nunimum requued wetwell pressure is determmed for a range of werwell temperatures using Equanon 2. Three different single ournp flew values are analyzad, including the rated RHR parnp riow of 4500 gpm. Table 4 documems the results of this calculation.
~
Summary and Candenians Thit calculation developed the minimum required wetwell airspace pressure to provide 3
adequate NDSH to the RHR and Core Spray pumps when suction is taken (mm the torus. Wetwell -
j pressures were developed for both one and two pump RHR and Core Spray operar. ion at Quad Cities Stanon Reqtured pressures for Core Spray pumps are bounded by those determined for the RHR pumos based on similar pump elevations and NPSHR curves, and lower Core Spray suction losses. it should be noted that there is no common suction piping for the Core Spray pumps so that the required werweil pressures for one ECCS pump operation apply to both one and two Core Spray pump operation.
i
7_
Qus Citix RHRICare Spray Minimum Wetwell Pressure Required TA6Lf_
4 Two Pumo Coeranen One Pume Ooormen l
l
@4500 Opm @5000 gpm' @6000 gpm ' @9000 gpml @10000 gomt@i?.000 gam Terus} '/apor Soec.1:e Me Wetwed Min Wetwed Min Wetwed Min Wetwed Min Wetwen Min Wetwed Tomo Pressure Volume-Pressure Pressurs
. Pressure Pressure Pressure Presaute
(%
ipsai (ft311bl (pmen fossat (osai insg)
Iceiei foes) 90 0.698 10.01610 8.46 I
9.75 15.35 9.28 10.77 16A2 100 0.949 0.01813 8.te l
9.99 15.57 9.51 11.01 17.04 110 1.275 0 01817 8.99 1
10.29 15A8 9A2 11.31 17.33 120 1.693 0.01620 9.39 10.89 15.25 10.22 11.70 17.71 130
- 2.223 0.01625 3.90 11.19 16.74 10.72 12.21 18.20 140 2.889 0.01629 10.55 1124 17.38 11.37 12A5 18 82 150 l 3.718 0.01634 11.35 12.64 18.15 12.17 13.64 19.60 160 1 4 741 10.01640
$ 2.35
$ 3.63 19.13 13.17-14.64 20.57 170' 5993 l 0.01646 13,58 14.85 20.33 1
14 39 15.85 21.77 160 7 511 0.01651, 15.07 18.34 21.80 15.88 1734 23.23 190 9.340 0.01657
'6.87 18.14 23.57 17.67 19.13 25.00 200 11 526 0.01664 19.03 20.29 25.70 1923 21.28 27.12 210 14 123 0.01671 2129 22.85 28.24 22.39 23A3 29.66 220 17.186 10.01678 24 83 2538 31.24 25.42 26.86 32.66 Torus Level = 13.52 ft.
@ 4800 Opm
@ 9000 gum (Orescan m:n torus NPSHR=
28 ft.
NPSHR=
28 ft level post LOCA Z=
14 39 ft.
Z=
14.39 ft.
w/ t tt. cruwocwns hl =
4.36 ft.
hl =
6.28 ft.
@ 5000 gym
@10000 9pm NPSHR=
30 n NPSHR =
30 ft.
Z=
1439 ft.
Z=
14 39 ft hL -
5.38 ft.
hL =
7.75 ft.
@ 6000 gpm
@ 12000 gpm NPSHR =
40.6 ft.
NPSHR-40.6 ft.
Z.
14 39 n.
Z.
1439 M.
hL =
7.75 ft hl =
1116 ft.
2
p Calculatios No. NED-M-MSD-59 Rev. 0 Quad Cities ECCS NPSH - Minim:na Required Wetwell Pressure i
t 4
1 Purnese<Obiective Calcutzte the minimum required wetull airspace pressure as a function of suppression pool j
temperature which is needed to provide adequate Not Posiuve Suction IIcad (NPS14 to the RHR and Core Spray pumps takmg suction from the suppresson poot 'This calculation includes analysis of both l
one and two ECCS pump operation.
i Anomotinm/innues
[
In addition to the assumptions made in Rdem.cc 1. the followmg assumptions and inputs are j
utilized in this calculation:
4
!) One set ofwetwell pressures will be generated for both the RiiR and Cbre Spray pumps.
9 Since both pumps have sumlar elevanons and NPSH curves, and since suction losses to the 1
Core Spray pumps are less than those for the RHR pumps (Raference 2), then the pressures deternuned for the RHR pumps bound the Core Spray pumps.
l
- 2) Torus levet elevanon is assumed to be 14.39' above pump cernerline, or 570.02'. This I
corresponds to the pos-LOCA mimamm torus level elevation used in the Dresden LPCI l
NPSII calm '%= (Reference 4). Assumed Quad Cities post LOCA minimum toms level
]
elevadon to be the same.
?
- 3) RHR/CS pump cemertine elevation = $55.625'(Reference 2).
- 4) RHR/CS NPSHR values shown in Table 3 (Reference 1).
1
- 5) RHR/CS one and two pump suction losses shown in Table I (References I and 2).
{
- 5) Tnis analysis includes single pump flows of 4500, 5000 and 6000 gpm, and two pump tiows j
of 9000,10000 and 12000 gpm.
References
?
i-Calculsion *NED M MSD-58 Rev. O, CHRON# 202807, dated 7/24/93.
- 2. " Base Suppression Pool Level required for proper operation of the RHR/LPCI and Core Spruy l
Pumps during plam cold shutdown and refueling conditions, NUTECH Calculation No.
d CWE097 0200.40, January 7,1992.
- 3. ASME Ster.m Tables, ;967.
- 4. "Dresden Port-LOCA LPCI/ Core Spray Pumps NPSH Evaluanon." Nuclear Engmeenng and Techno!cgy Semces Calculation #NED M-MSD-54 Rev. 0, CHRON# 200691, dated 4/30/93.
~u.;..
Ccicuhta N5. NED-M MSD 59 Rev. 0 Quad Cities ECCS NPSH - Minimum Required WetweG Pressure Kananmu l
Net Positive Suction Head Available (NPSHA) in foot is determined using the following equation:
)
i NPSHA = 144 v (Pt - vp) + z - hL (1)
I where: Pt - Torus Prussure(psia) l vp = 'sturationPressure(psia) l hl = r2ctionlosses(fast)
= specificvolume(ft8Mb) v z = head of water above pump inlet (fast) l
= torus water eley - pump centerline elev i
- 570.02'- 555.625' I
= 14.39' i
Solving Equanon 1 in terms of the wetwell(torus) pressure provides the following:
1 Pt - WWR - r + hL + vp (2) f 144v i
For a given flow, the required NPSH (NPSIDL), the head of weser above the pump (z) and the suction losses (hL) are constam. The specine volume (v) and vapor pressure (vp) are a function of I
wetweil temperature.
l herian tzas l
Suetion losses for one pump operation (Reference 2) and two pump operadon (Reference 1) of RHR and Core Spray are provided in Table i below:
l TotalSuction Losses (feet) l One Pump Two Pumps Pump
@ 4500 gym
@ 9000 gpm RHR 4.36 i
6 28 Core Spray 2.4 2.4 Table 1
... ~ -
~ --
.. _ ~
Calculation No. NED M-MSD 59 Rev. 0 Quad Cities ECCS NPSH - Minimum Required Wetwell Pressure Since both the RHR ano Core Spray pumps have similar elevations and NPSHR curves. the Core Spray pumps are bounded in this analysis by'the RHR pumps due to the difference in suction Ic,sses. To determine the 6ienonal losses at any one or two pump flow. the quadratic re between head loss and flow establishes the followmg:
head losa,. - head loss, x (flowyflow )8 (3) i Therefore. the nuction losses for the flows to be analyzed are:
One Pump '
Suction i Two Pump Suction Flow (spm) Losses (tt)! Flow (spm) Lasses (ft) 4.500 4.36 9.000 6.28 5,000 5.38 10,000 7.75 6,000 7.75 12,000 l 11.16 Table 2 C415E180058 The nunimum required wetwell pressure is determmed for a range of werwell temperatures using Equadon 2. Three diferent single cump f!cw values are analyzed, including the mted RHR pump flow of 4500 gpm. Table 4 docum:nts the resuks of this calculation.
Summary and Cancineiane This calculation developed the minimum required wetwell airspace pressure to provide adequare NPSH to the RHR and Core Spray pumps whan suction is taken from the torus. Wetwen,
pressures were developed for both one and two pt:mp RHR and Core Spray operadon at Quad Cities Station. Raquired pressures for Core Spray pumps are bounded by those determmed for the RHR pumos based on similar puma elevations and NPSHR curves, and lower Core Spray suction losses. it should be noted that there is no common suction piping for the Core Spray pumps so that the required wetwed pressures for one ECCS pump operation apply to both one and two Core Spray pump operation.
[
CaIculation No. NED-M-MSD 59 R:v. O Quad Cities ECCS NPSH - Minimurn Required Wetwell Pressure f
o Quad Cities RHR/ Care Spray Pumps NPSH Required (Reference ()
Mow NPSHR Mow NPSHR (gym)
(ft)
(gpm)
(ft) 3,500 l 25 5,500 i 35 3,800 25.5 5,600 36.1 4,000 26 5,7C0 37.2 4,500 28 5,800 t 38.4 5,000 l 30 l 5.900 l 39.5 5,300 l 33 l 6,000 l 40.6 Table 3 4
5 5
-i
,=
l GENE-637-022-0893 l
APPENDIX C USAR BENCHMARK ANALYSIS
(
{
t i
A benchmark case was performed with the SHEX code using the same input assumptions as those used for the USAR analysis for Case e of USAR Table 6.2-3.
Table C.1 summarizes the changes made to the key inputs and assumptions of Section 3 and 4.
The core heat used in the analysis, which is shown in Table I
C.2, was based on.the May-Witt decaf heat model.
l RESULTS:
l Figure C.1 shows the long-term suppression pool ter.iperature response for the USAR bench mark case.
The calculated peak s:topression pool temperature with SHEX for the USAR bench mark case is 181*F waicn is 4*F higher than the value of 177'F reported in Table 6.2-3 of the USAR for Case e.
C-1
=.
J GENE.-637-022-0893 Table C.1 - Key Parameters used for the'tiSAR Bench Mark Analysis Parameter y.glyg Decay Heat May-Witt Feedwater None g.
l l
Initial Pool 90 Temperature
(*F)
RHR HX Heat 276.1 Transfer Coefficient (Btu /Sec 'F)
- 84.5 Heat Removal (million 8tu/hr)
Referenced to a Suppression Pool Temperature of 180*F and a Service Water Temperature of 95'F (AT - 85'F)
C-2
GENE-637-022-0893 TABLE C.2 - CORE HEAT BASED ON MAY W TT F.AY HEAT MODEL Time (sec)
Core Heat
- 1 0.0 1.0232 0.1 1.0092 0.2
.9785 i
0.6
.7467 0.8
.6966 1.0
.5860 2.0
.5541 3.0
.5921 4.0.
.5830 6.0
.5486 8.0
.4733 10.
.3859 20.
.08943 30..
.07161 40.
.05378 60.
.04937 80.
.04727 100.
.04588 120.
.04499 121.**
.03718 200.
.03365 600.
.02549 1000.
.02229 2000.
.01841 4000.
.01512 6000.
.01353 10000.
.01201 20000.
.01008 40000.
.008125 60000.
.007394~
- Core Heat (nomalized to the initial core thermal power of 2561 mwt)
- - decay heat + fission power + fuel relaxation energy + metal-water =
reaction energy
- Metal-water reaction heat is assumed to end at 120 seconds.
c-3 FORINFORMATION ONLY p
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