ML061290390
| ML061290390 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/01/2005 |
| From: | Operations Branch IV |
| To: | Southern California Edison Co |
| References | |
| 50-361/05-301, 50-362/05-301, ES-D-1 | |
| Download: ML061290390 (6) | |
Text
Appendix D Scenario Outline Form ES-D-1 Facility:
San Onofre Scenario No.:
1 Op Test No.:
NRC Examiners:
Operators:
Initial Conditions:
100% power - RCS Boron is 891 ppm Train A Component Cooling Water Pump (P-025) in service Train A Saltwater Cooling Pump (P-307) OOS Train A Low Pressure Safety Injection Pump (P-015) OOS Condenser Air Ejector Low Range Radiation Monitor (RM-7818) OOS Turnover:
Maintain steady-state power conditions.
Critical Tasks:
Transfer the Non-Critical Loop (SWC failure)
Isolate affected Steam Generator Reduce Thot to < 530°F Event No.
Malf. No.
Event Type*
Event Description 1
TS (CRS)
SWC Pump trip P-112 (seized shaft).
2
+30 min RC24A C (CO, CRS)
TS (CRS)
Spray valve fails open (PV-0100A @ 40%).
3
MFWP speed signal fails low (P-062 speed control).
4
+60 min SG06A C (CO, CRS)
TS (CRS)
SG tube leak on E-088 (~50 gpm).
5
+70 min R (CO)
Rapid down power due to SG tube leak on E-088.
6
+80 min SG06A M (ALL)
SGTR on E-088.
7
+80 min PG21 Unit output breaker fails to open.
8
+80 min K403B I (CO)
SIAS relay failure.
(N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS) Technical Specifications Appendix D NUREG 1021 Revision 9
Appendix D Scenario Outline Form ES-D-1 SCENARIO
SUMMARY
- 1 The crew will assume the shift at 100% power and maintain steady-state conditions per SO23-5-1.7, Power Operations.
When turnover is complete a Saltwater Cooling Pump will trip due to a seized shaft. The crew will respond per SO23-2-17, Component Cooling System Operation and/or AOI SO23-13-7, Loss of Component Cooling Water (CCW) / Saltwater Cooling (SWC). The crew will align SWC & CCW Train B per pump configuration requirements. The SRO will be required to evaluate Technical Specifications.
When the CCW and SWC systems are properly aligned the Pressurizer Spray Valve will fail 40%
open. Crew will respond and stabilize primary plant using Annunciator Response Procedures (ARP) and Abnormal Operating Instruction (AOI) SO23-13-27, Pressurizer Pressure and Level Malfunction. The SRO will be required to evaluate Technical Specifications.
When plant is stable and the instrument card for the Pressurizer Spray Valve is pulled (valve closes) a Main Feed Water Pump speed signal will fail high. Crew will regain control of feedwater pump per Annunciator Response Procedures and AOI SO23-13-24, Feedwater Malfunctions.
Once stable, a small tube leak will occur. The SRO will be required to evaluate Technical Specifications and enter AOI SO23-13-14, Reactor Coolant System Leak. The SRO will determine that a rapid downpower per SO23-5-1.7, Power Operations is required. Once the power change is underway and the crew has demonstrated plant control during the power reduction, the leak will become a rupture and cause a plant trip. The crew performs SO23-12-1, Standard Post Trip Actions and diagnoses a SGTR and enters SO23-12-4, Steam Generator Tube Rupture (SGTR). The crew will be required to isolate the affected SG and reduce Thot to <
530°F. A Generator Output Breaker will fail to open on Turbine trip and actuate the Breaker Failure Local Backup (BFLBU). A SIAS relay failure will require the operator to position three (3)
Train B SIAS valves to their SIAS position.
Scenario is terminated when the affected SG is isolated, Thot is < 530°F, and plant conditions are stable.
Risk Significance:
Risk important components out of service:
LPSI P-015, SWC P-307 Failure of risk important system prior to trip:
SWC Pump seizure Risk significant core damage sequence:
SGTR with SIAS failure Risk significant operator actions:
Manually initiate SIAS Transfer the Non-Critical Loop Appendix D NUREG 1021 Revision 9
Appendix D Scenario Outline Form ES Facility:
San Onofre Scenario No.:
2 Op Test No.:
NRC Examiners:
Operators:
Initial Conditions:
50% power - RCS Boron is 1043 ppm by Chemistry sample Train A Component Cooling Water Pump (P-025) in service Train A Saltwater Cooling Pump (P-307) OOS Train A Low Pressure Safety Injection Pump (P-015) OOS Condenser Air Ejector Low Range Radiation Monitor (RM-7818) OOS Turnover:
Boration and down power required for taking the Turbine off-line for planned maintenance.
Critical Tasks:
Respond to ATWS by de-energize B15 & B16 Start Component Cooling Water Pump following SDVS Event No.
Malf. No.
Event Type*
Event Description 1
+15 min R (CO)
Commence boration and down power following turnover at 15%/hour.
2
Turbine Governor Valve fails closed (UV2200B).
3
+40 min RC11A I, (CO, CRS)
RCS Th Loop 1 TT-0111X1 fails HIGH to 625°F.
4
+50 min PG22 PG23 C (ACO, CRS)
TS (CRS)
Degraded grid to SDVS setpoint.
5
+55 min SEISMIC OBE w/o FWPT Seismic event without Feedwater Pump trip.
6
+65 min RC03 C (CO, CRS)
TS (CRS)
RCS leak requiring a plant shutdown (~30 gpm).
7
+75 min RC03 M (ALL)
LOCA @ 500 gpm.
8
+75 min RP03 C (ACO)
Auto and manual Reactor trip failure (ATWS).
9
+75 min MS03B M (ALL)
ESDE on E-089 inside Containment.
10
+75 min EC08DA C (CO)
HPSI Pump (P-018) trip.
(N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS) Technical Specifications Appendix D NUREG 1021 Revision 9
Appendix D Scenario Outline Form ES SCENARIO
SUMMARY
- 2 The crew will assume the shift with a boration required to remove the Turbine from service for pre-planned maintenance per SO23-5-1.7, Power Operations.
After the crew has demonstrated control of the power change an HP Turbine Governor Valve will fail closed. The crew will respond per the Annunciator Response Procedures (ARP) and SO23-10-3, Operation of the Turbine Control and Protection System.
With the plant in a stable condition a Thot instrument fails high and will require crew actions per the ARPs and Abnormal Operating Instruction (AOI) SO23-13-27, Pressurizer Pressure and Level Malfunction. This is followed by a frequency drop and grid voltage decrease to the Sustained Degraded Voltage Signal (SDVS) for 110 seconds that will require crew response and entry into AOI SO23-13-4, Operation during Major System Disturbances. The ACO will be required to maximize Generator MVARs and restart a CCW Pump. The CRS will evaluate Technical Specifications.
With plant conditions stable a seismic event will occur. The crew will perform actions in AOI SO23-13-3, Earthquake. Initially an RCS leak of about 30 gpm will require the crew to determine that a plant shutdown is required. After Technical Specifications have been evaluated, an aftershock will result in a loss of Coolant Accident and Steam Line Break along with an ATWS. The crew will respond to the ATWS by opening breakers to B15 and B16. The crew performs SO23-12-1, Standard Post Trip Actions and diagnoses a LOCA and an ESDE and transition to SO23-12-9, Functional Recovery.
During the Functional Recovery a HPSI Pump P-018 will trip. The CO will be required to manually start HPSI Pump P-017. The scenario is terminated when RCS temperature and pressure are stabilized while in the Functional Recovery procedure and associated Floating Steps.
Risk Significance:
Risk important components out of service:
LPSI P-015, SWC P-307 Risk significant core damage sequence:
LOCA with HPSI failure Risk significant operator actions:
Manually trip Reactor on ATWS Start a CCW Pump on SDVS Appendix D NUREG 1021 Revision 9
Facility:
San Onofre Scenario No.:
3 Op Test No.:
NRC Examiners:
Operators:
Initial Conditions:
~25% power - RCS Boron is 1123 ppm Train A Component Cooling Water Pump (P-025) in service Train A Saltwater Cooling Pump (P-307) OOS Train A Low Pressure Safety Injection Pump (P-015) OOS Condenser Air Ejector Low Range Radiation Monitor (RM-7818) OOS Turnover:
Dilution and power increase in progress at 10% per hour.
Critical Tasks:
Transfer Component Cooling Water for Non-Critical Loop.
Energize Vital AC Buses A06 & B06 with G003.
Event No.
Malf. No.
Event Type*
Event Description 1
+15 min R (CO)
Dilution and power increase in progress.
2
+25 min CV14 C (CO, CRS)
Loss of Primary Water Makeup Pumps.
3
+30 min RC22C TS (CRS)
RCS Cold Leg Temperature Transmitter Failure to the Core Protection Calculators.
4
+40 min CV19 I (CO, CRS)
Letdown Temperature instrument fails low.
5
+50 min ED07C C (ALL)
TS (CRS)
Loss of Inverter Y003.
6
+65 min Severe weather (tornado watch).
TU08 Turbine trip due to electric governor failure.
7
+65 min PG24 M (ALL)
Loss of Off-site Power (+ 5 seconds).
8
+65 min EG08A C (ACO)
Mechanical failure of EDG G002.
9
+70 min EG07B C (ACO)
EDG G003 AVR failure requires manual adjustment for breaker closure.
(N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS) Technical Specifications Appendix D NUREG 1021 Revision 9
SCENARIO
SUMMARY
- 3 The crew will assume the shift at approximately 25% power with a dilution in progress. The crew will raise power per SO23-5-1.7, Power Operations.
After the crew has demonstrated control of the power change, the Primary Water Makeup Pumps trip and are addressed per the Annunciator Response Procedures (ARP). A Tcold Protection Channel failure will occur on Plant Protection System Channel C. The crew will respond per the Annunciator Response Procedures, Abnormal Operating Instruction (AOI) SO23-13-18, Reactor Protection System Failure and the CRS will evaluate Technical Specifications.
With the plant stable the crew will respond to a Letdown Temperature Instrument Failure. This will require action per the Annunciator Response Procedures. A vital bus failure will cause the crew to enter AOI SO23-13-18, Loss of Vital Bus. The CRS will evaluate Technical Specifications and the bus will be re-energized from the alternate supply per SO23-6-17, 120 VAC Vital Bus Power Supply System Operation.
When the Vital Bus is restored, the crew will receive a tornado watch from the National Weather Service and will enter AOI SO23-13-8, Severe Weather. The crew will be required to prepare for the tornado watch by performing actions inside and outside the Control Room.
A Loss of Off-Site power will occur and the crew will respond to a plant trip per SO23-12-1, Standard Post Trip Actions and will transition to SO23-12-7, Loss of Forced Circulation / Loss of Off-Site Power. A mechanical failure of an emergency diesel generator coupled with an EDG breaker that fails to close due to the setting of the automatic voltage regulator will require the operator to adjust and manually close the output breaker.
Event termination will occur once an off-site line is restored, the crew has re-energized 2A03 or 2A07, and plant temperature and pressure are stable.
Risk Significance:
Risk important components out of service:
LPSI P-015, SWC P-307 Failure of risk important system prior to trip:
Loss of Vital Inverter Risk significant core damage sequence:
Failure to recover from LOOP Risk significant operator actions:
EDG failure Appendix D NUREG 1021 Revision 9