ML22193A322
| ML22193A322 | |
| Person / Time | |
|---|---|
| Site: | Quad Cities  |
| Issue date: | 04/07/2021 |
| From: | Randy Baker NRC/RGN-III/DRS/OLB |
| To: | Exelon Generation Co |
| Baker R | |
| Shared Package | |
| ML20139A013 | List: |
| References | |
| Download: ML22193A322 (16) | |
Text
Quad Cities 2021 NRC EXAM Scenario 1 Appendix D Scenario Outline Form ES-D-1 Facility: Quad Cities Scenario: 2021 NRC Scenario 1 Op-Test No.: ILT 20-1 Examiners: ________________________ Operators:_____________________________
Initial Conditions: 90% Reactor power, SSMP and 2A Turb. Bldg. Exhaust fan are out of service.
Turnover: Place the 2A SWP in service and secure the 2B SWP. Continue load increase to full power with Recirc flow.
Critical Tasks:
- 1. While executing QGA 200, Primary Containment Control, when Torus pressure exceeds 5 psig and only if operating in the safe region of the drywell spray initiation limit (DSIL), INITIATE drywell sprays. (BWROG PC-5.1 INIT DW SPRAY)
- 2. Per QGA 100, RPV Control, with the automatic ADS timer initiated, INHIBIT ADS before an automatic actuation occurs and cooldown rates are exceeded. (BWROG RPV-4.2/5.2/6.2)
- 3. If the RPV level trend is not reversible with an L3 system capable of providing adequate core cooling, INITIATE an emergency depressurization before Minimum Steam Cooling RPV Water Level (MSCRWL). (BWROG RPV-1.1 LOSS HP INJ E/D TAF)
Event No.
Malf. No.
Event Type*
Event Description 1
None BOP N
Swap the 2A and 2B Service Water Pumps.
2 None ATC R
Raise Reactor power with Recirculation pumps.
3 NM08D ATC C/TS APRM 4 fails downscale / RBM 8 inoperable.
4 RD08A ATC C
1A CRD Pump reduced capacity.
5 DIHS15705C BOP C
1C TB Exhaust Fan trip w/ failure of standby fan to start.
6 PC04B SRO TS Drywell-Torus Vacuum Beaker fails open.
7 RR11A CREW M
LOCA (1A Recirc Pump discharge line break).
8 ED04B ED03B HP08 CREW Loss of Reactor Feed Pumps and HPCI.
9 CS04A CREW C
1A Core Spray Pump autostart failure.
Quad Cities 2021 NRC EXAM Scenario 1 10 None CREW TAF / RPV Blowdown.
(N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor ES-301-4 Quantitative attributes:
Total Malfunctions (5-8): 7 Malfunction(s) after EOP (1-2): 8, 9 Abnormal Events (2-4): 3, 4, 6, 8 Major Transient(s) /E-Plan entry (1-2): 7 EOPs (1-2): 100 / 200 EOP Contingencies (0-2): 100ALC/ 100BD Critical Tasks (2-3): 3 ES-301-5 Quantitative attributes:
BOP Normal: 1 ATC Reactivity (1 per set): 2 BOP I/C (4 per set): 6, 8 ATC I/C (4 per set): 3, 4 SRO-I I/C (4 per set inc 2 as ATC): 3, 4, 6, 8 SRO Tech Spec (2 per set): 3, 5 ALL Major Transients (2 per set): 7
Quad Cities 2021 NRC EXAM Scenario 1
SUMMARY
Initial Conditions:
o The plant is currently at 90% power with the SSMP and 2C RB Exhaust Fan out of service o Electrical Maintenance has requested the 2B Service water pump secured and removed from service for a motor inspection.
Event 1: Swap Service Water Pumps: The BOP will start the 2A Service Water pump and secure the 2B Service Water pump per QCOP 3900-01.
Event 2: Reactor Power Maneuver: The ATC will raise reactor power with Recircs to full power (2957 MWth) per QCGP 3-1 and the ReMA.
Event 3: APRM 4 Downscale Failure: After the reactivity addition is complete, APRM 4 fails downscale rendering both APRM 4 and RBM 8 inoperable. The SRO will contact Instrument Maintenance to investigate. The SRO will enter TS 3.3.2.1. Condition A (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore RBM channel). The SRO directs the ATC to bypass APRM 4 per QCOP 0700-04 and exits the TS LCO.
Event 4: 1A CRD Pump reduced capacity: The ATC reports annunciator 901-5 F-2, CRD CHARGING WATER LOW PRESSURE, alarm. ATC observes and reports lowering CRD parameters. An EO dispatched to the 1A CRD pump reports that the motor is running hot and possible bearing damage. The SRO directs the ATC to swap CRD pumps per QCOP 0300-23.
Event 5: 1C TB Exhaust Fan trip: The BOP acknowledges annunciator 912-5 A-2, and reports the 1C TB Exhaust Fan has tripped and the standby did not autostart. The BOP starts the standby, 1A TB Exhaust Fan successfully. Turbine Building D/P is restored to < 0 in. H2O.
Event 6: Drywell-Torus Vacuum Breaker fails open: The BOP reports annunciators 901-3 C-13 and 901-3 G-11 are in alarm. An EO performing a system walkdown with a new engineer reports a test pushbutton on the 2251-24 panel was inadvertently bumped and the 1601-32B Drywell to Torus Vacuum breaker has an open indication. Attempts to close it were not successful. The SRO enters TS 3.6.1.8 Condition C, One Vacuum Breaker not closed (4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to restore).
Event 7/10: LOCA / TAF Blowdown: The crew will insert a manual scram on high Drywell pressure due to a break in the A Recirc Loop Suction Line. Actions per QGA 100 and QGA 100 Alternate Level Control leg will be taken to try and maintain RPV water level above -142 inches (MSCRWL). Containment parameters will be controlled per QGA 200 actions. When conditions permit, the crew will blowdown the RPV, and restore level with low pressure ECCS systems.
Event 8: Loss of Reactor Feed Pumps and HPCI: After the reactor scram and main turbine trip, the RAT fails to transfer to Bus 11 and Bus 12 trips on overcurrent resulting in a loss of all RFPs. The HPCI Aux Oil Pump trips on motor overload preventing HPCI startup.
Event 9: 1A Core Spray Pump autostart failure: The 1A Core Spray pump fails to autostart on high Drywell pressure. The BOP will manually start the pump.
Approximate Run Time: 1.5 Hours
Quad Cities 2021 NRC EXAM Scenario 1 CRITICAL TASKS:
Critical Task #1: While executing QGA 200, Primary Containment Control, when Torus pressure exceeds 5 psig and only if operating in the safe region of the drywell spray initiation limit (DSIL),
INITIATE drywell sprays. (BWROG PC-5.1 INIT DW SPRAY)
Clarification: This critical task is not met if Drywell sprays are not initiated after 5 psig Torus pressure. The evaluation should consider how promptly sprays are started after 5 psig is reached. This judgement should take into account the containment pressure trend and then determine when opportunity was available to initiate Drywell sprays. Crew resource availability and priorities should also be considered in this evaluation.
Critical Task #2: Per QGA 100, RPV Control, with the automatic ADS timer initiated, INHIBIT ADS before an automatic actuation occurs and cooldown rates are exceeded. (BWROG RPV-4.2/5.2/6.2)
Clarification: This critical task is not met if RPV level and/or Drywell pressure reach their respective automatic ADS actuation setpoint(s), ADS initiates, and cooldown rates are exceeded due to ADS actuation.
Critical task #3: If the RPV level trend is not reversible with an L3 system capable of providing adequate core cooling, INITIATE an emergency depressurization before Minimum Steam Cooling RPV Water Level (MSCRWL). (BWROG RPV-1.1 LOSS HP INJ E/D TAF)
Clarification: This critical task is not met if the MINSRED ADS valves (5) are not taken to manual prior to -162 inches. This critical task may be trend dependent, and the evaluation team can adjust the criteria if level was stable near MSCRWL prior to unexpected plant change.
Quad Cities 2021 NRC EXAM Scenario 3 Appendix D Scenario Outline Form ES-D-1 Facility: Quad Cities Scenario: 2021 NRC Scenario 3 Op-Test No.: ILT 20-1 Examiners: ________________________ Operators:_____________________________
Initial Conditions:
The plant is at 75% power for Main Turbine Stop Valve Testing.
Turnover: Perform QCOS 5600-13, for Main Turbine Stop Valves 3 and 4.
Raise power per QCGP 3-1 and the ReMA.
Critical Tasks:
- 1. With a reactor scram required and the reactor not shutdown, TAKE ACTION TO REDUCE POWER by injecting boron (above 5% reactor power) and/or inserting control rods, to prevent exceeding primary containment design limits. (BWROG RPV-6.1 ATWS PWR/LVL S/D REACTOR)
- 2. Per QGA 101, RPV Control (ATWS), with a reactor scram required, the reactor not shutdown, and the automatic ADS timer initiated, INHIBIT ADS before an automatic initiation occurs. (BWR RPV-6.2 ATWS PWR/LVL INHIBIT ADS)
- 3. During an ATWS with conditions met to perform power/level control, TERMINATE AND PREVENT INJECTION (with the exception of boron, CRD, and RCIC) into the RPV until conditions are met to re-establish injection. (BWROG RPV-6.3 /LVL TERM/PREVENT)
- 4. Per QGA 101, during an ATWS with RPV injection terminated and prevented, when RWL drops below -35, slowly raise and control injection rate to MAINTAIN RPV water level above the Minimum Steam Cooling RPV Water Level (MSCRWL) without causing a sustained rise in reactor power. (BWROG RPV-6.4 ATWS PWR/LVL RESTORE RPV LVL)
Event No.
Malf. No.
Event Type*
Event Description 1
None BOP N
Test MSVs 3 and 4 per QCOS 5600-13.
2 None ATC R
Raise Reactor power with control rods.
3 RD02R ATC C
Stuck Control Rod 4
NM10A ATC C/TS RBM 7 downscale failure 5
AD01D BOP C/TS D Relief Valve fails open (setpoint drift)
Quad Cities 2021 NRC EXAM Scenario 3 6
SW11A BOP C
1A TBCCW Pump degrades 7
TU02C TU02E TU02I CREW M
Main Turbine Bearing high vibration / SCRAM 8
RD13A RD13B CREW C
Full Core Hydraulic ATWS (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor ES-301-4 Quantitative attributes:
Total Malfunctions (5-8): 6 Malfunction(s) after EOP (1-2): 8 Abnormal Events (2-4): 3, 4, 5, 6, Major Transient(s) /E-Plan entry (1-2): 7 EOPs (1-2): QGA 100 EOP Contingencies (0-2): QGA 101 Critical Tasks (2-3): 4 ES-301-5 Quantitative attributes:
BOP Normal: 1 ATC Reactivity (1 per set): 2 BOP I/C (4 per set): 5, 6 ATC I/C (4 per set): 3, 4 SRO-I I/C (4 per set inc 2 as ATC):3, 4, 5, 6 SRO Tech Spec (2 per set): 4, 5 ALL Major Transients (2 per set): 7
Quad Cities 2021 NRC EXAM Scenario 3
SUMMARY
Initial Conditions:
o The plant is currently at 75% power for Main Turbine Stop Valve testing.
o Perform QCOS 5600-13 for MSVs 3 and 4, then raise power per QCGP 3-1 and the ReMA.
Event 1: The BOP performs QCOS 5600-13 steps H.2.h., H.2.i., and H.2.j. for MSVs 3 and 4.
Event 2: Reactivity: The ATC will raise reactor power by withdrawing control rods per the ReMA.
Event 3: Stuck Rod: After two control rods have been withdrawn to target out, the third control rod will not move with normal drive water pressure (260 to 320 psid). The ATC take actions per QCOA 0300-02 step D.7 and throttle drive water pressure in 50 psid increments. When drive water pressure is raised to ~360 psid, the control rod will withdraw normally.
Event 4: RBM 7 Downscale: The ATC responds to RBM Downscale and Rod Out Block alarms. The SRO directs ATC to hold power constant and directs ATC/BOP to determine status of RBMs. ATC and BOP report RBM 7 is reading downscale at the 901-5 and 901-37 panels.
The SRO directs the ATC to bypass RBM 7 per QOA 700-05 and enters TS 3.3.2.1 Condition A (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to restore channel to operable status).
Event 5: D Relief Valve Fails Open: The BOP reports annunciators 901-3 E-13, E-14 and E-16 are in alarm. The BOP determines D ADS valve is open. The SRO directs actions of QCOA 0201-03. The relief valve closes when the keylock switch is taken to OFF. The SRO enters TS 3.4.3 Condition A (14 days to restore) and TS 3.5.1 Condition H (14 days to restore).
Event 6: 1A TBCCW Pump Degrades: The 1A TBCCW pump degrades 50% resulting in a low system pressure and associated alarms on the 912-1 panel. The BOP will start the standby and restore system parameters. The EO dispatched will report the 1A TBCCW pump motor casing hot.
Event 7: Main Turbine Bearing High Vibration / SCRAM. Main Turbine bearing #s 3, 5, and 9 fail resulting in high vibration (901-7 D-2) and temperature (901-7 G-1) alarms. The BOP monitors and reports vibration levels at VR 1-5640-60, MAIN TB VIBRATION, EXPANSION AND ECCENTRICITY on the 901-7 panel. The SRO directs actions of QCOA 5600-01. When bearing vibration levels reach 10 mils the ATC inserts a manual scram and the BOP trips the turbine.
Event 9: Hydraulic ATWS. A hydraulic lock on the North and South Scram Discharge Volumes prevents control rod insertion. The SRO directs actions of QGA 101. The ATC will take actions to shutdown the reactor by injecting SBLC and individually inserting control rods. The BOP will control RPV pressure in band. RPV water level will be controlled in until the Hot Shutdown weight of Boron is injected. The scenario ends when RPV level is restored to a band of 0 to 48 in. and RPV pressure is stable in band.
Approximate Run Time: 1.5 Hours
Quad Cities 2021 NRC EXAM Scenario 3 CRITICAL TASKS:
Critical Task #1: With a reactor scram required and the reactor not shutdown, TAKE ACTION TO REDUCE POWER by injecting boron (above 5% reactor power) and/or inserting control rods, to prevent exceeding primary containment design limits. (BWROG RPV-6.1 ATWS PWR/LVL S/D REACTOR)
Critical Task #2: Per QGA 101, RPV Control (ATWS), with a reactor scram required, the reactor not shutdown, and the automatic ADS timer initiated, INHIBIT ADS before an automatic initiation occurs. (BWR RPV-6.2 ATWS PWR/LVL INHIBIT ADS)
Clarification: This critical task is not met if RPV level and/or drywell pressure reach their respective automatic ADS actuation setpoint(s) but ADS is not prevented before the conditions specified.
Critical Task #3: During an ATWS with conditions met to perform power/level control, TERMINATE AND PREVENT INJECTION (with the exception of boron, CRD, and RCIC) into the RPV until conditions are met to re-establish injection. (BWROG RPV-6.3 /LVL TERM/PREVENT)
Clarification: This critical task is not met if either of the reactor power or level thresholds is not met when terminate and prevent actions are taken or if both conditions are met and terminate and prevent actions are not taken at all. The timing of this evaluation is dependent upon execution of the level control leg of QGA 101. Though ATWS execution strategies may vary, the evaluation should include a level of expediency which adequately addresses the potential concern for thermal hydraulic instabilities. This expediency is subjective, so the evaluation team must assess whether the delay was acceptable and warranted.
In addition, the critical task is also not met if either Boron or CRD is secured when either or both are required to lower reactivity during an ATWS condition. The QGAs clearly prioritize reactivity reduction in all ATWS situations. Compromising the ability to accomplish this potentially places the plant at greater safety risk.
Critical Task #4: Per QGA 101, during an ATWS with RPV injection terminated and prevented, when RWL drops below -35, slowly raise and control injection rate to MAINTAIN RPV water level above the Minimum Steam Cooling RPV Water Level (MSCRWL) without causing a sustained rise in reactor power. (BWROG RPV-6.4 ATWS PWR/LVL RESTORE RPV LVL)
Clarification: This critical task applies to the QGA 101 level leg step 4, when the RWL drops below -35 (two feet below feedwater spargers). This critical task is not met if RPV injection is recommenced BEFORE reaching -35. This would result in unnecessary reactivity addition (from subcooled water) while RWL is being intentionally lowered to suppress power.
Inversely, this critical task is not met if an attempt to inject is not recommenced prior to RWL reaching MSCRWL. If a prolonged loss of core cooling is observed (i.e., RWL allowed to lower below MSCRWL prior to recommencement of RPV injection), the evaluation team must determine the nature of the event and whether operator action contributed to it. If so, a judgement must be made to determine if this warrants a missed critical task here.
This critical task is also not met if RPV injection rate is too fast, resulting in a sustained positive reactivity event. The evaluation team must observe the power response as injection is recommenced and determine if the response has potential to cause fuel damage.
Quad Cities 2021 NRC EXAM Scenario 4 Appendix D Scenario Outline Form ES-D-1 Facility: Quad Cities Scenario: 2021 NRC Scenario 4 Op-Test No.: ILT 20-1 Examiners: ________________________ Operators:_____________________________
Initial Conditions:
The plant is operating at 100% power, holding load.
Day 2/30 TLCO 3.3.b. Condition A, 3C Relief Valve Acoustic Monitor.
Turnover: Perform QCOS 0203-01, Safety and Relief Valve Acoustic Monitor Surveillance, for 1-203-3C Relief Valve as a PMT.
Critical Tasks:
- 1. The Crew will take action to isolate the RPV and reduce the release of radioactivity by manually closing the MSIVs, Main Steam drains and verifying the Off-Gas System is isolated prior to a required QGA 400 entry.
- 2. With a primary system discharging into the reactor building and the discharge cannot be isolated, verify/INITIATE an emergency depressurization when two or more areas of the same parameter (radiation, temperature, or water levels) are above max safe IAW QGA 300 and appropriate RPV blowdown leg.
Event No.
Malf. No.
Event Type*
Event Description 1
None BOP N
Acoustic Monitor Test 2
FW08A ATC C
1A Feed Reg Valve Lockup 3
RD04R ATC C /TS Control Rod Drifts Out 4
SER0201 BOP C/TS ADS Timer Actuation 5
FW14A ATC R
1A1 Feedwater Heater Tube leak /
Emergency Power Reduction.
6 None BOP C
Reclose LP Heater String Bypass Valve 7
CR01 RD14A CREW M
SDV leak & Fuel Failure RPV Blowdown (2 areas above max safe rad levels) 8 DIHS10590303 CREW C
Scram Reset Switch Failure
Quad Cities 2021 NRC EXAM Scenario 4 (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor ES-301-4 Quantitative attributes:
Total Malfunctions (5-8): 5 Malfunction(s) after EOP (1-2): 1 Abnormal Events (2-4): 2, 3, 4, 5 Major Transient(s) /E-Plan entry (1-2): 7 EOPs (1-2): QGA 100 / 300 EOP Contingencies (0-2): 100BD Critical Tasks (2-3): 2 ES-301-5 Quantitative attributes:
BOP Normal: 1 ATC Reactivity (1 per set): 5 BOP I/C (4 per set): 4, 6 ATC I/C (4 per set): 2, 3 SRO-I I/C (4 per set inc 2 as ATC): 2, 3, 4, 6 SRO Tech Spec (2 per set): 3, 4 ALL Major Transients (2 per set): 7
Quad Cities 2021 NRC EXAM Scenario 4
SUMMARY
Initial Conditions:
o The plant is operating at 100% power, holding load.
o TLCO 3.3.b. Condition A, Function 2, for the 1-203-3C Relief Valve Acoustic Mon.
Event 1: BOP Normal: Perform QCOS 0203-01, Safety and Relief Valve Acoustic Monitor Surveillance, as a PMT for the 1-203-3C Relief Valve.
Event 2: 1A FRV Lockup: The 1A Feed Reg Valve locks up due to a loose connector on the LVDT. Instrument Maintenance will tighten the loose connection and the ATC reset the lockup and restore the 1A FRV control to automatic mode.
Event 3: Control Rod Drift: The ATC responds to a drift alarm and reports control rod H-10 is drifting out. The SRO directs actions of QCOA 0300-11 and the control rod is fully inserted, scrammed and electrically disarmed. The SRO declares the rod inoperable and enters TS 3.1.3 Condition C.
Event 4: ADS Timer Actuation: The BOP reports annunciator 901-3 B-13, AUTO BLOWDN TIMER START, in alarm. The SRO directs the BOP to take actions of the QCAN. The BOP attempts to reset the Timer, then inhibits ADS. The SRO declares ADS inoperable and enters Event 5/6: 1A1 Feedwater Heater Tube Leak: A tube leak in the 1A1 Heater results in a Low Pressure Heater String isolation. The SRO directs actions of QCOA 3500-01 and the ATC performs an emergency power reduction per QCGP 3-1. When total feedwater flow is < 7.6 Mlb/hr and the heater high level alarm has cleared (901-6 G-1), the BOP closes the 1-3403 LP HTR STRING BYP VLV terminating the reactivity transient.
Event 7: Fuel Failure/SDV Leak: A Fuel failure results from the reactivity transient. The crew will respond to virus high radiation alarms and announce evacuation of the Reactor and Turbine Buildings. Radiation Protection will be directed to set up access control and Chemistry to obtain coolant and effluent samples. The SRO directs a manual reactor scram on OffGas Hi Hi effluent. An RP Tech reports large steam and water leak from the North Scram Discharge Volume. Radiation level on the 1st, 2nd, and 3rd floor of the Reactor Building and the Torus area will exceed max safe levels. The SRO will direct an RPV blowdown per QGA 100.
Event 8: Scram Reset Switch Failure: The ATC will attempt to isolate the SDV leak by resetting the reactor scram, however, the switch fails and the scram cannot be reset.
Approximate Run Time: 1.5 Hours
Quad Cities 2021 NRC EXAM Scenario 4 CRITICAL TASKS:
Critical Task #1: The Crew will take action to isolate the RPV and reduce the release of radioactivity by manually closing the MSIVs, Main Steam drains and verifying the Off-Gas System is isolated prior to a required QGA 400 entry.
Critical Task #2: With a primary system discharging into the reactor building and the discharge cannot be isolated, verify/INITIATE an emergency depressurization when two or more areas of the same parameter (radiation, temperature, or water levels) are above max safe IAW QGA 300 and appropriate RPV blowdown leg.
Clarification: The critical task is not met if an emergency depressurization is NOT performed when multiple areas reach max safe values for the same parameter with an unisolable primary system leak discharging into the areas -or-if an emergency depressurization is performed before indications are present in multiple areas. In some cases, regarding radiation levels, control room indications will not provide adequate information. In such cases, local surveys will be needed and sound operational judgement will need to be applied. The evaluation team must determine if the local reports justify performing an emergency depressurization in such cases, especially where accessibility is limited.
Quad Cities 2021 NRC EXAM Scenario 5 Appendix D Scenario Outline Form ES-D-1 Facility: Quad Cities Scenario No.: 2021 NRC Scenario 5 Op-Test No. ILT 20-1 Examiners: ________________________ Operators:_____________________________
Initial Conditions:
The plant is currently at 75% power and holding load for a revision to the ReMA.
Turnover: Perform the Core Spray Monthly surveillance for the 1B Core Spray pump.
Critical Tasks:
- 1. With a failure of both Recirc Pump Inboard and Outboard seals, accompanied by an increase in Drywell pressure OR temperature, isolate the leak by closing the pump suction and discharge valves.
- 2. When executing QGA 200, Primary Containment Control, when Torus level cannot be maintained above 11 feet, manually SCRAM and INITIATE emergency RPV depressurization.
Event No.
Malf. No.
Event Type*
Event Description 1
None BOP N
Perform Core Spray Monthly Surveillance (1B Core Spray pump) 2 NM14L1633 ATC C
LPRM Upscale failure 3
ANO9128A8 SRO TS SSMP Room Cooler inoperable.
4 DIHS156041A LOHS156041A BOP C
1A Gland Exhauster trip.
5 DIFC10262222 RAISE ATC C
Recirc Pump Master Controller fails high 6
RR06A RR06B BOP C/TS Recirc Pump Seal Leak 7
None ATC R
Emergency Power Reduction for Loss of Recirc Pump 8
PC07 CREW M
Torus Leak 9
RP05A/C CREW C
Scram / Spurious Group I Isolation 10 None CREW C
Blowdown on Low Torus Level
Quad Cities 2021 NRC EXAM Scenario 5 (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor ES-301-4 Quantitative attributes:
Total Malfunctions (5-8): 6 Malfunction(s) after EOP (1-2): 9 Abnormal Events (2-4): 2, 4, 5, 6 Major Transient(s) /E-Plan entry (1-2): 8 EOPs (1-2): 100, 200, 300 EOP Contingencies (0-2): 100BD Critical Tasks (2-3): 2 ES-301-5 Quantitative attributes:
BOP Normal: 1 ATC Reactivity (1 per set): 7 BOP I/C (4 per set): 4 & 6 ATC I/C (4 per set): 2 & 5 SRO-I I/C (4 per set inc 2 as ATC): 2,4,5,6 SRO Tech Spec (2 per set): 3 & 7 ALL Major Transients (2 per set): 8
Quad Cities 2021 NRC EXAM Scenario 5
SUMMARY
Initial Conditions:
o The plant is operating at 75% power, holding load for a ReMA revision.
Event 1: The BOP performs QCOS 1400-04, Core Spray Pump Operability Test for the 1B Core Spray Pump.
Event 2: LPRM Upscale Failure: LPRM 16-33C fails upscale high causing APRM 2 to also indicate high. The SRO will direct the ATC and BOP to bypass the LPRM per QCOP 0700-
- 03. Prior to bypassing the LPRM, the crew will determine APRM 2 will NOT have the minimum required C level inputs. The SRO will direct the ATC to bypass APRM 2, then LPRM 16-33C.
Event 3: SSMP Room Cooler Inoperable: The BOP will dispatch an EO to the SSMP Room in response to the 912-8 A-8, Safe Shutdown System Trouble alarm. The EO will report that the Compressor Trip light is lit on the Room Cooler. The EO will attempt a reset as directed by the BOP, however, it will be unsuccessful. The SRO will declare the SSMP inoperable due to an inoperable room cooler and enter TS 3.7.9 Condition A (14 days) for both Units.
Event 4: 1A Gland Exhauster Trip: The running Gland Seal Exhauster will trip. The BOP will start the standby Exhauster and adjust Gland Exhaust pressure.
Event 5: Master Recirc Controller Failure: The Master Recirc Controller will fail high resulting in APRM power, Total Core Flow, and Recirc Pump speeds all showing an increasing trend.
There are several ways for the ATC operator to take manual control and terminate the transient, ie. speed hold, placing Recirc controllers in individual manual, or depressing the LOWER pushbutton on the Master Controller.
Event 6: Recirc Pump Seal Leak: The ATC will report degradation of the 1A Recirc pump seals. When Drywell pressure and temperature rise the SRO will direct the ATC to trip the 1A Recir pump and isolate it by closing the pump suction and discharge valve. The SRO enters TS 3.4.1 Condition C Event 7: Emergency Power Reduction: The SRO will direct the action for QCOA 0202-04 for the loss of a Recirc Pump. The ATC will insert control rods and the BOP will lower the operating Recirc pump speed. The plant will be stabilized at a lower power with operation within MELLLA and outside of ICA Region II.
Event 8: Torus Leak: The BOP will respond to annunciator 901-3 A-14, TORUS HIGH/LOW LEVEL and report Torus level at -0.5 inches and lowering. The EO dispatched to the Reactor Building basement reports a large leak in the ECCS ring header. QGA 200 is entered when Torus level drops below -2 inches. Attempts to raise Torus level and repair the leak are unsuccessful and the reactor is scrammed at 12 ft. Torus level.
Event 9: Scram/Group I: A spurious Group I occurs simultaneously with the manual scram.
The crew will use ADS valves to initiate a cooldown as the Group I will not reset.
Event 10: Blowdown: The crew will blowdown the RPV at 11 ft. Torus level by opening all five ADS valves.
Approximate Run Time: 1.5 Hours
Quad Cities 2021 NRC EXAM Scenario 5 CRITICAL TASKS:
Critical Task #1: With a failure of both Recirc Pump Inboard and Outboard seals, accompanied by an increase in Drywell pressure OR temperature, isolate the leak by closing the pump suction and discharge valves.
Critical Task #2: When executing QGA 200, Primary Containment Control, when Torus level cannot be maintained above 11 feet, manually SCRAM and INITIATE emergency RPV depressurization.
Clarification: This critical task is not met if emergency depressurization is not performed when conditions indicate that Torus level cannot be held above 11 feet.
Meeting this critical step neither requires nor prohibits actions before the limit is reached. The actions may be taken as soon as it is decided that the limit will ultimately be exceeded or delayed until Torus level actually reaches the limit. If Torus level drops below the limit, the actions must be performed and they may not be delayed while attempts are made to restore Torus level to >11 feet. If necessary, this will require some discussion among the evaluation team.
This critical step is also not met if the reactor has NOT been scrammed before emergency depressurization is initiated. This would result in automatic PCIS and RPS actuations due to MSIV closure.