ML021630294
| ML021630294 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/11/2002 |
| From: | Robert Beaton, Bessette D ISL, Office of Nuclear Regulatory Research |
| To: | |
| References | |
| Download: ML021630294 (15) | |
Text
Beaver Valley RELAP5 PTS Analysis David Bessette, USNRC Robert Beaton, ISL, Inc.
2 Beaver Valley T/H Analysis
- Model received from Westinghouse was developed from the HB Robinson plant model.
- Model needed modifications/corrections to run a null transient (maintain quasi-steady conditions).
- Trip setpoints used by Westinghouse were licensing values. Best-Estimate plant setpoint values are used (obtained from current Tech Specs).
3 Beaver Valley T/H Analysis
- Transient runs (such as reactor trip/turbine trip) were made to shake down the model.
Corrections were made based on the results of these runs.
- Control variables were added to compute quantities of interest to PTS analysis (i.e.,
minimum downcomer temperature, etc.)
4 Sump Recirculation
- ECCS water injection switches from RWST to sump recirculation when RWST volume drops to 287,000 gallons
- Is potentially important to PTS risk predictions since ECC injection temperature will increase from 50°F to 124°F at switchover
- Assumptions
- constant sump temperature of 124°F
- containment sprays come on between 365 sec (for 1.0 SBLOCA) to 302 sec (for 22 SBLOCA)
5 Beaver Valley T/H Analysis
- List of transients was based on input from NRC, Sandia and SAIC
- Events selected to identify runs that provide broad coverage of possible PTS sequences.
- There are also some runs that we would expect to be relatively benign (however, as we have seen we cannot simply assume that they are not of concern).
6 Beaver Valley T/H Analysis
- Preliminary Transient Events Include:
- LOCA Spectrum (1.0 inch through 8.0 inch)
- Reactor Trip w/Stuck Open Primary Relief Valve (PORV, SRV)
- Reactor Trip w/Stuck Open Secondary Side Valves (1, 2, and 3 stuck valves)
- Main Steam Line Break
- Steam Generator Tube Rupture
7 Beaver Valley T/H Analysis
- Average Downcomer Fluid Temperature, Pressure and Downcomer Wall Heat Transfer Coefficient are passed to FAVOR
- FAVOR analysis of other plants indicates that stuck pressurizer relief valves which reclose are significant risk contributors
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS 8.0 inch Surge Line Break (Case 007)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS 5.657 inch Surge Line Break (Case 006)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS 4.0 inch Surge Line Break (Case 005)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS 2.828 inch Surge Line Break (Case 004)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS RTT w/Feed and Bleed (Case 031)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:17 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:17 2002 BV PTS RTT w/2 Stuck Open Pressurizer SRVs (Case 034)
Wed May 8 11:04:17 2002
0 3000 6000 9000 12000 15000 Time (s) 0 100 200 300 400 500 600 Temperature (F)
Average Downcomer Fluid Temperature Wed May 8 11:04:18 2002 0
3000 6000 9000 12000 15000 255 366 478 589 Temperature (K)
Wed May 8 11:04:18 2002 0
3000 6000 9000 12000 15000 Time (s) 0 500 1000 1500 2000 2500 3000 Pressure (psia)
Average Downcomer Pressure Wed May 8 11:04:18 2002 0
3000 6000 9000 12000 15000 0.0 3.4 6.9 10.3 13.8 17.2 20.7 Pressure (MPa)
Wed May 8 11:04:18 2002 0
3000 6000 9000 12000 15000 Time (s) 0 0.5 1
1.5 HTC (Btu/s*ft 2*F)
Average Downcomer Wall Heat Transfer Coefficient Wed May 8 11:04:18 2002 0
3000 6000 9000 12000 15000 0
10221 20442 30663 HTC (W/m 2*K)
Wed May 8 11:04:18 2002 BV PTS RTT w/2 Stuck Open Pzr SRVs which reclose (Case 062)
Wed May 8 11:04:18 2002
15 Beaver Valley T/H Analysis
- Additional Transient Events to be Simulated
- Larger LOCAs (up to 22 hot leg breaks)
- Stuck valves which reclose after system depressurized
- Events which start from Hot Zero Power
- Others based on PRA?