ML20189A090
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Oconee Nuclear Station UFSAR Appendix 8A. Tables Appendix 8A. Tables
Oconee Nuclear Station UFSAR Table 8-1 (Page 1 of 2)
Table 8-1. Loads to be Supplied from the Emergency Power Source This table will provide a list of Oconee loads which automatically start after a LOOP or LOCA, and the Oconee loads which are required to mitigate the event. This table demonstrates that the transformers have adequate capacity to supply the required Oconee loads. Loads may be added at the option of the operator to help mitigate the event. The additional loads are not listed in this table.
I. Equipment automatically loaded after load shed (KVA).
Unit 1 Unit 2 Unit 3 Equipment LOCA LOOP LOCA LOOP LOCA LOOP H.P. Injection Pump 1800 hp 1200 hp 1800 hp 1200 hp 1800 hp 1200 hp L.P. Injection Pump 800 hp 0 800 hp 0 800 hp 0 L.P. Service Pump (1) 1200 hp 600 hp 600 hp 600 hp 1200 hp 600 hp R.B. Spray Pump 500 hp 0 500 hp 0 500 hp 0 Emerg. Fdw Pump 1000 hp 1000 hp 1200 hp 1200 hp 1200 hp 1200 hp R.B. Cooling Fans 225 hp 225 hp 225 hp 225 hp 225 hp 225 hp ESV Pump (2) 50 hp 50 hp 50 hp 50 hp 50 hp 50 hp Pene Rm. Vent Fans 10 hp 0 10 hp 0 10 hp 0 MOVs (3) 100 kva 0 100 kva 0 100 kva 0 Safety MCCs 375 kva 375 kva 375 kva 375 kva 375 kva 375 kva Auto Load LCs (4) 1290 kva 1290 kva 1290 kva 1290 kva 1290 kva 1290 kva Keowee Aux. Power 750 kva 750 kva 0 0 0 0 Total (5) 7743 kva 5130 kva 6274 kva 4489 kva 6803 kva 4489 kva II. Equipment required to run for event mitigation (KVA)
H.P. Injection Pump 600 hp 600 hp 600 hp 600 hp 600 hp 600 hp L.P. Injection Pump 400 hp 0 400 hp 0 400 hp 0 L.P. Service Pump 600 hp 600 hp 600 hp 600 hp 600 hp 600 hp R.B. Spray Pump 250 hp 0 250 hp 0 250 hp 0 Emerg. Fdw Pump 0 1000 hp 0 1200 hp 0 1200 hp R.B. Cooling Fans 225 hp 225 hp 225 hp 225 hp 225 hp 225 hp HPSW Pumps 1000 hp 1000 hp 0 0 0 0 Pene Rm. Vent Fans 10 hp 0 10 hp 0 10 hp 0 ESV Pump 25 hp 25 hp 25 hp 25 hp 25 hp 25 hp Safety MCCs 375 kva 375 kva 375 kva 375 kva 375 kva 375 kva Auto Load LCs 1290 kva 1290 kva 1290 kva 1290 kva 1290 kva 1290 kva (31 DEC 2019)
Oconee Nuclear Station UFSAR Table 8-1 (Page 2 of 2)
Keowee Aux. Power 750 kva 750 kva 0 0 0 0 Chiller Comp (6) 350 hp 350 hp 350 hp 350 hp 825 hp 825 hp Chill. SW Pumps (6) 25 hp 25 hp 25 hp 25 hp 0 0 Chill. Wtr Pm (6) 30 hp 30 hp 30 hp 30 hp 0 0 AC Sys. Fan (6) 20 hp 20 hp 20 hp 20 hp 0 0 Total (5) 5534 kva 5834 kva 3902 kva 4378 kva 4255 kva 4731 kva III. Combined Load Demand for Station Starting Running LOCA KVA 7743 5534 LOOP KVA (7) 4489 4003 LOOP KVA (7) 4489 4003 Total KVA 16,721 13,540 IV. Source Size Two Keowee Units 2@87.5 MVA = 175 MVA Startup Transformers (CT1, CT2, CT3) = 45/60 MVA each Standby Transformers (CT4, CT5) = 12/16/20/22.4 MVA each V. Summary Transformers CT1, CT2, CT3, CT4, CT5 and Keowee hydro generators are sized adequately to provide power for Oconee loads required to start and/or run during a LOCA/LOOP event. There is sufficient margin in the transformer and generator sizing to allow the operator to start additional loads as desired to assist in event mitigation. There is sufficient guidance given to the operator so that transformer ratings will not be exceeded.
Note:
- 1. LPSW-B pump is shown fed from Unit 1.
- 2. The ESV Pumps will automatically start 2 minutes after power becomes available.
- 3. Loading for MOVs is an approximate value.
- 4. Auto loading non-safety load centers will delay loading for 30 seconds when the Standby Bus is supplied from a Lee Combustion Turbine.
- 5. KVA was calculated using a combined power factor-efficiency of .85 for all loads shown in horsepower.
- 6. Only 1 unit would be supplying a chiller. Unit 3 would supply a temporary chiller if the other 2 were out of service.
(31 DEC 2019)
Oconee Nuclear Station UFSAR Table 8-2 (Page 1 of 2)
Table 8-2. Single Failure Analysis for 125 Volt DC Switching Station Power Systems Component Malfunction Comments & Consequences
- 1. 480V AC Power Loss of power to No consequence - power from battery is Supply to Charger one available to supply power without interruption.
- 2. Battery Charger Loss of power from (a) The 125 volt dc bus would continue to one receive power from its respective battery without interruption except as in (c) below.
(b) Standby battery charger may be manually aligned.
(c) Battery Charger internal faults may cause high short circuit currents to flow resulting in voltage reduction on the 125 volt dc bus until the fault is cleared by the isolating circuit breakers. Complete loss of voltage on the 125 volt dc bus may result if the battery circuit breakers open. However, redundant protective relaying and panelboards are provided and are supplied from the other redundant 125 volt dc bus.
- 3. 125V DC Battery Loss of power from Only those 125 volt dc control one panelboards supplied from the affected bus will be lost. The redundant panelboards supplied from the other 125 volt dc bus would be unaffected and continue to provide power for protection and control.
- 4. DC Distribution Bus shorted Same comment as 3.
Center Buses P-N
- 5. 125V DC Bus SY- Grounding a single The 125 volt dc system is an 1, SY-2, SY-3, SY- bus (P or N) ungrounded electrical system. Ground 4 detector equipment monitors and alarms upon a ground anywhere on the 125 volt dc system. A single ground will not cause any malfunction or prevent operation of any safety feature.
- 6. 125V DC Bus SY- Gradual decay of Each 125 volt bus is monitored to detect 1, SY-2, SY-3, SY- voltage on one bus the voltage decay on the bus and initiate 4 an alarm at a setting above a voltage where the battery can deliver power for safe and orderly shutdown of the station.
Upon detection power will be restored by correcting the deficiency.
(31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-2 (Page 2 of 2)
Component Malfunction Comments & Consequences
- 7. DC Distribution Cables shorted Same comments as 3.
Center Load Feeder Cables
- 8. 125V DC Primary Bus shorted in one (a) Voltage on associated 125 volt dc bus or Backup panelboard will decay until isolated by isolating Panelboards circuit breakers.
(b) Protective relaying connected to the affected panelboards may be lost; however, redundant protective relaying supplied from the other 125 volt dc bus would provide protection.
(c) One source of control power may be lost to the switching station power circuit breakers; however, a redundant source of control power is provided from the other 125 volt dc bus.
(31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-3 (Page 1 of 2)
Table 8-3. Single Failure Analysis for the Keowee Hydro Station Component Malfunction Comments & Consequences
- 1. Keowee Hydro Loss of one (a) One emergency power source would be Units lost; however, the other unit would supply 100% of emergency power load.
(b) If the 13.8 kV underground feeder were selected to the unit which was lost, it would also be lost; however, the other unit would supply power through the stepup transformer and the 230 kV switching station to the startup transformers and the underground feeder could be transferred by the Oconee operator to the running unit.
- 2. Generator Circuit Loss of one Same as 1 above.
Breakers and Buses
- 3. Stepup Loss of one Both hydro units would be separated from Transformer, Low the 230 kV switching station; however, one Side Buses, 230 kV hydro unit would supply emergency power Overhead Line and through the 13.8 kV underground circuit.
PCB-9
- 4. 13.8 kV Loss of one One circuit of emergency power would be Underground lost; however, both units could supply Feeder Circuit emergency power over the 230 kV Breaker, Cables, or overhead line. Although a ground fault Transformer would cause the underground unit to lockout, the lockout could be reset allowing the Keowee Unit to restart so that it could supply emergency power over the 230 kV overhead line.
- 5. Keowee Hydro Loss of one unit's Same as 1 above.
Unit Automatic system Startup and Unit Control Systems
- 6. Keowee Hydro Loss of one Same as 1(a) above.
Unit 125V DC Control Battery, Panelboard, Feeders, etc.
- 7. Keowee Hydro Loss of one Same as 1(a) above.
Unit Emergency Startup and Switching Logic (31 DEC 2019)
Oconee Nuclear Station UFSAR Table 8-3 (Page 2 of 2)
Component Malfunction Comments & Consequences
- 8. Keowee Hydro Loss of one No Consequence, since independent and Unit Emergency redundant underground signal cables are Startup and provided.
Switching Circuits from Oconee
- 9. Underground Loss of underground Overhead assigned Keowee Hydro Unit assigned Keowee assigned Keowee would be automatically realigned to provide Hydro Unit Hydro Unit and power to underground path. Auxiliary loads generating to the overhead path for overhead assigned Keowee Hydro Unit grid during would be automatically realigned to receive commercial power from Transformer CX.
generation or testing (31 DEC 2019)
Oconee Nuclear Station UFSAR Table 8-4 (Page 1 of 2)
Table 8-4. Single Failure Analysis for the Emergency Electrical Power Systems Component Malfunction Comments & Consequences
- 1. Any 230 kV Bus, Loss of one On loss of the yellow bus, the 230 kV PCB-18, 27 and emergency power circuit would be lost until PCB-30, 230 kV the Oconee operator could reroute this Circuit to Startup supply in the switching station. However, Transformers, emergency power would be available CT1, CT2, CT3, through the 13.8 kV underground circuit and Associated from one of the Keowee units. Other Buses singular losses would have no consequence.
- 2. 230 kV Power Loss of one No consequence as two trip coils are Circuit Breaker provided for each circuit breaker and each Trip Coils or trip coil is provided with a separate 125 volt 125V DC Trip dc control circuit.
Coil Power Supply
- 3. 13.8 kV Loss of one One circuit of emergency power would be Underground lost; however, both hydro units could Circuit from supply emergency power over the 230 kV Keowee Hydro overhead line. Although a ground fault or Transformer would cause the underground unit to No. CT4 lockout, the lockout could be reset allowing the Keowee Unit to restart so that it could supply emergency power over the 230 kV overhead line.
- 4. 4160V Main (a) One circuit No consequence, as sufficient redundant Feeder Buses, breaker fails to circuit breakers and buses are provided 4160V Stand-by close when with redundant switching logic.
Power Buses required to and Feeder supply Circuit Breakers emergency power.
(b) One bus section No consequence as sufficient redundant faults circuit breakers and buses are provided with redundant switching logic.
- 5. 4160 V Auxiliary Loss of one Same as 4(a) above.
Switchgear Bus Section
- 6. 600V Auxiliary Loss of one One 600 volt bus section containing Switchgear Bus engineered safeguards would fail to Sections receive emergency power; however, sufficient redundant engineered safeguards will be supplied from the remaining redundant buses to perform the engineered safeguards function.
(31 DEC 2014)
Oconee Nuclear Station UFSAR Table 8-4 (Page 2 of 2)
Component Malfunction Comments & Consequences
- 7. 125V DC Single failures See Section 8.3.2.2.1 and Table 8-5 for System single failure analysis.
- 8. 120V AC Vital Single failures See Section 8.3.2.2.3 and Table 8-6 for Power Buses single failure analysis.
(31 DEC 2014)
Oconee Nuclear Station UFSAR Table 8-5 (Page 1 of 4)
Table 8-5. Single Failure Analysis for 125 Volt DC Instrumentation and Control Power System Component Malfunction Comments & Consequences
- 1. 600V AC Power Loss of power to Power from battery is available to Supply to one supply power without interruption until charger standby charger is switched in.
- 2. Battery Charger Loss of power from (a) The 125 volt dc bus would continue to one receive power from its respective battery without interruption except as in (2c) below.
(b) Standby battery charger may be manually aligned.
(c) Battery Charger internal faults may cause high short circuit currents to flow resulting in voltage reduction on the 125 volt dc bus until the fault is cleared by the isolating circuit breakers. Complete loss of voltage on the 125 volt dc distribution center may result if the battery circuit breakers open. However, power to reactor protection systems and engineered safeguards instrumentation and control would be unaffected since they are supplied from redundant feeders.
- 3. 125V DC Loss of power from (a) Those 125 volt dc control panelboards Battery one supplied from the affected bus will continue to receive uninterrupted power from their alternate power supplies through isolating diodes.
(b) All power could be lost to the other loads supplied from the faulted bus; however, they are not associated with reactor instrumentation, protective systems, or engineered safeguards.
- 4. 125V DC Bus shorted Same comment as 3a and 3b .
Distribution Center Buses P-N (31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-5 (Page 2 of 4)
Component Malfunction Comments & Consequences
- 5. 125V DC Grounding a single (a) The 125 volt dc system is an Distribution bus (P or N) ungrounded electrical system. Ground Center DCA, detector equipment monitors and DCB alarms a ground anywhere on the 125 volt dc system. A single ground will not cause any malfunction or prevent operation of any safety feature.
- 6. 125V DC Gradual decay of (a) Each 125 volt bus is monitored to Distribution voltage on one bus detect the voltage decay on the bus and Center DCA, initiate an alarm at a setting above a DCB voltage where the battery can deliver power for safe and orderly shutdown of the station. Upon detection, power will be restored either by correcting the deficiency by switching to a redundant source or by employing one of the redundant circuits.
- 7. DC Distribution Cables shorted (a) Same comments as 3a 3b.
Center Load Feeder Cables
- 8. Isolating Diodes Failure of one (a) If the diode fails shorted then the other series diodes will still provide adequate isolation and power will be uninterrupted.
(b) If the diode fails open then the other redundant supply through its isolating diodes will continue to supply power without interruption.
- 9. 125V DC Bus shorted (a) Voltage on two of the 125 volt dc bus Control Power systems will decay until isolated by the Panelboard isolating circuit breakers causing 1DIA, 1DIB, consequences same as comments 3a 1DIC, 1DID, and 3b. At most, one panelboard in a 2DIA, 2DIB, single unit could be lost.
2DIC, 2DID, 3DIA, 3DIB, 3DIC or 3DID (31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-5 (Page 3 of 4)
Component Malfunction Comments & Consequences (b) For one unit, one-half of control and instrumentation power not associated with reactor instrumentation and protective systems or engineered safeguards will be degraded until the shorted panel board isolates, after which one-fourth of the loads would be lost. Control and instrumentation power associated with reactor instrumentation and protective systems or engineered safeguards is covered in 9(g).
(c) For one unit, one-half of 6900 volt switchgear closing control power could be lost but dual trip coils and redundant tripping power supplies are provided.
(d) For one unit, one-third of the 4160 volt switchgear closing control power could be lost. Dual trip coils and redundant tripping control power are provided.
The remaining redundant switchgear is adequate and is supplied control power from the other dc panels.
(e) For one unit, the 4160 volt main feeder bus circuit breakers on only one of the two buses could lose closing control.
All 4160 volt circuit breakers have redundant trip coils and power supplies.
The remaining main feeder bus and circuit breakers are supplied control power from the other dc panels, permitting the switching of 4160 volt emergency power to any unit.
(f) For one unit, the 600 volt load center(s) associated with the affected panel will lose dc control power; however, each load connected to the load center(s) has an alternate feed from a redundant load center.
(31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-5 (Page 4 of 4)
Component Malfunction Comments & Consequences (g) One static inverter would be lost and power to one instrument bus would be lost temporarily until a manual transfer could be made to a regulated instrument bus. The temporary loss of one vital instrument bus would result in the temporary loss of one channel of reactor protection and instrument systems and engineered safeguards systems. Other remaining channels will receive vital instrument control power from the other panelboards.
(31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-6 (Page 1 of 1)
Table 8-6. Single Failure Analysis for the 120 Volt AC Vital Power System Component Malfunction Comments & Consequences
- 1. 125V DC Control Bus shorted One static inverter would be lost and Power power to one instrument bus would be Panelboard 1DIA, lost temporarily until a manual transfer 1DIB, 1DIC, could be made to a regulated instrument 1DID, 2DIA, bus. The temporary loss of one vital 2DIB, 2DIC, instrument bus would result in the 2DID, 3DIA, temporary loss of one channel of reactor 3DIB, 3DIC or protection and instrument systems and 3DID engineered safeguards systems. Other remaining channels will receive vital instrument control power from the other panelboards.
- 2. Static Inverter Failure Same as comment 1.
Feeder Cable
- 3. Static Inverter Failure Same as comment 1.
- 4. Vital Instrument Failure of one For any one bus failure only one channel Power of any system associated with reactor Panelboard instrumentation and protective systems 1KVIA, 1KVIB, or engineered safeguards would be lost.
1KVIC, 1KVID, Sufficient redundant channels supplied 2KVIA, 2KVIB, from other vital instrument buses would 2KVIC, 2KVID, provide adequate protection.
3KVIA, 3KVIB, 3KVIC or 3KVID (31 DEC 2000)
Oconee Nuclear Station UFSAR Table 8-7 (Page 1 of 1)
Table 8-7. 125 Volt DC Panelboard Fault Analysis (31 DEC 2000)