ML22195A280
| ML22195A280 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/23/2021 |
| From: | Randy Baker NRC/RGN-III/DRS/OLB |
| To: | |
| Baker R | |
| Shared Package | |
| ML21055A860 | List: |
| References | |
| Download: ML22195A280 (6) | |
Text
Appendix D Scenario Outline Form ES-D-1 Facility:
Dresden Generating Station Scenario No.:
2021-302 ILT-N-2 Op-Test No.: 2021-302 Examiners Operators
/ crew position
/ ATC
/ BOP
/ CRS Initial Conditions: Unit 2 is at 80% Power 2C Reactor Feed Pump is out of service for motor replacement.
Turnover:
Swap Stator Water Cooling Pumps for maintenance.
Critical Tasks:
RPV-1.1 - If the RPV level trend is not reversible with an RPV injection source lined up with a pump running, initiate emergency depressurization with RPV water level between the Top-of-Active Fuel and the Minimum Steam Cooling RPV Water Level or within two and 1/2 minutes after TAF is reached, whichever is later.
RPV-1.5 - Per DEOP 100, RPV Control, with the automatic ADS timer initiated, inhibit ADS before an automatic actuation occurs.
PC-1.1 - While executing DEOP 200-1, Primary Containment Control, when drywell pressure exceeds 9 psig and only if operating within the safe region of the drywell spray initiation limit (DSIL), initiate drywell sprays.
Event No.
Malf.
No.
Event Type*
Event Description #
1 NONE N
BOP (New) - GENERATOR - SWC Pump Swap for Maintenance 2
RDPPBTRP C
ATC (Pre) - CRD - Pump Swap due to Grinding Noise 3
NONE R
ATC (New) - REACTIVITY - Emergent Load Drop 4
HPINIT I/T BOP CRS (New) - HPCI - Spurious Initiation 5
RODL06DI C/T ATC CRS (New) - CRD - Rod Drift 6
MGDDBTR C
BOP (New) - GENERATOR - Bus Duct Blower Trip 7
SER1363 F43 M
ALL (New) - FEEDWATER - System High Vibes (Manual Scram) with Recirc Leak 8
T13 C
BOP (New) - AUX POWER - Failure of EDG to Auto Start 9
F43 M
ALL (Pre) - EMERGENCY DEPRESSURIZE - On Lowering RPV Water Level Due To Recirc System Leak and Loss of All Reactor Feed Pumps
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (T)ech Spec
- (New) - Event not used on previous 2 NRC Exams, (Pre) - Event used on previous 2 NRC Exams
Appendix D Scenario Outline Form ES-D-1 Event #
Description 1
GENERATOR - SWC Pump Swap for Maintenance:
The BOP will start the standby Stator Water Cooling pump and secure the running pump.
2 CRD - Pump Swap due to Grinding Noise:
While on their round, an EO will report grinding noise in the 2B CRD Pump. The crew will start the standby CRD pump and secure the running CRD Pump. The running CRD pump will trip on its own after 10 minutes if no action is taken.
3 REACTIVITY - Emergent Load Reduction:
The TSO calls and informs the crew that a 75 MWe load reduction is required for grid stability. The ATC lowers power using CRAM rods and/or Recirc flow per DGP 03-01.
4 HPCI - Spurious Initiation:
A spurious initiation of HPCI occurs. The crew will verify HPCI is not needed, then secure and isolate it.
Technical Specification 3.5.1 Condition G applies.
5 CRD - Rod Drift:
Control rod E-06 drifts in. The crew will take actions per DOA 0300-05, Inoperable or Failed Control Rod Drives. Technical Specification 3.1.3 Condition C applies.
6 GENERATOR - Bus Duct Blower Trip:
The running Bus Duct Blower trips on overcurrent. The BOP will start the standby Bus Duct Blower.
7 FEEDWATER - System High Vibes (Manual Scram) with Recirc Leak:
High Feedwater vibrations will come in one at a time until action is taken to insert a Manual Scram and secure all Reactor feed pumps. A Recirc leak will also start on the scram causing level to slowly lower.
8 AUX POWER - Failure of EDG to Auto Start:
Once the crew performs a manual SCRAM and level drops to less than -59 inches, the 2/3 EDG will fail to start automatically. The BOP can start the EDG manually by taking the control switch to RUN.
9 EMERGENCY DEPRESSURIZE - On Lowering RPV Water Level Due to Recirc System Leak and Loss of All Reactor Feed Pumps:
Following the scram, water level lowers and HPCI is degraded if the crew attempts to start it. With insufficient HP injection sources available to overcome the leak rate, an ED will be performed on low RPV level. The team will recover RPV level with LP ECCS systems.
Appendix D Scenario Outline Form ES-D-1 Facility:
Dresden Generating Station Scenario No.:
2021-302 ILT-N-3 Op-Test No.: 2021-302 Examiners Operators
/ crew position
/ ATC
/ BOP
/ CRS Initial Conditions: Unit 2 is in Mode 2. DGP 01-01 is in progress Turnover:
Transfer MCC 28-7/29-7 from Bus 28 to Bus 29.
TS LCO 3.5.1.E - For LPCI Injection valves powered from reserve power supply.
Critical Tasks:
RPV-5.1 - With a reactor scram required and the reactor not shutdown, take action per DEOP 400-5, Failure to Scram, to reduce power by inserting control rods.
RPV-5 Per DEOP 400-5, Failure to Scram, with a reactor scram required, the reactor not shutdown, and the automatic ADS timer initiated, inhibit ADS before an automatic actuation occurs.
Event No.
Malf.
No.
Event Type*
Event Description #
1 NONE N
BOP (Pre) - AUX POWER - Transfer MCC 28-7/29-7 from Bus 28 to Bus 29 2
NONE R
ATC REACTIVITY - Raise Power with Rods 3
RDFCVFCL C/T ATC CRS (New) - CRD - Flow Control valve Fails Closed 4
HP6 HP7 C
BOP (New) - CIRC WATER - Pump Trip on Overcurrent 5
NONE C
ATC (New) - FEEDWATER - RFP Swap due to Oil Leak 6
ADS3ESD C/T BOP CRS (Pre) - MAIN STEAM - ERV Spurious Open 7
Q31 I21 M
ALL (New) - Manual Scram - Loss of all Service Water with small steam leak in Drywell 8
RDHLVFPA RDHLDEGA RDHLVFPB RDHLDEGB M
ALL (Pre) - ATWS - Hydraulic, ARI Unsuccessful / Team Inserts Rods By Manually Drive Rods
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (T)ech Spec
- (New) - Event not used on previous 2 NRC Exams, (Pre) - Event used on previous 2 NRC Exams
Appendix D Scenario Outline Form ES-D-1 Event #
Description 1
AUX POWER - Transfer MCC 28-7/29-7 from Bus 28 to Bus 29:
The BOP will transfer power to MCC 28-7/29-7 from Bus 28 to Bus 29 2
REACTIVITY - Raise Power with Rods:
The team will continue raising reactor power by withdrawing control rods until 2 main turbine bypass valves are fully opened.
3 CRD - Flow Control Valve Fails Closed:
The CRD Flow Control Valve fails closed. This causes the controller demand to the CRD FCV to fail high, but all indications are the valve is closed. If the team does not recognize the failure quickly and restore CRD cooling flow, the ROD DRIVE TEMP HI alarm comes up. The Team directs in-plant operators to swap CRD flow control valves and restores CRD flow control to normal.
4 CIRC WATER - Pump Trip on Overcurrent:
The 2A Circulating water pump trips on overload. The Team starts the 2B Circulating water pump.
5 FEEDWATER - RFP Swap due to Oil Leak:
The Team receives a report from the field that 2A RFP has an oil leak. The Team starts 2B or 2C RFP and secures 2A RFP.
6 MAIN STEAM - ERV Spurious Open:
2C ERV setpoint will drift causing 2C ERV to open. The BOP will attempt to close the ERV from the MCR per DOA 0250-01, Relief Valve Failure. The ERV will close after cycling the Inhibit switch.
7 Manual Scram - Loss of all Service Water:
An unisolable Cribhouse Service Water leak downstream of the Service Water strainers occurs. The Team will perform a manual scram due to the loss of cooling to vital plant equipment. A small steam leak occurs once the reactor is scrammed.
8 ATWS - Hydraulic, ARI Unsuccessful / Team Inserts Rods by Manually Drive Rods:
Following the scram, the control rods will not fully insert. ARI will also fail to insert the control rods due to a hydraulic lock. The team will ultimately be successful in achieving reactor shutdown by driving control rods and performing repeated scram resets.
Appendix D Scenario Outline Form ES-D-1 Facility:
Dresden Generating Station Scenario No.:
2021-302 ILT-N-4 Op-Test No.: 2021-302 Examiners Operators
/ crew position
/ ATC
/ BOP
/ CRS Initial Conditions: Unit 2 is at 70% power.
Turnover:
U2 EDG Surveillance Test in progress per DOS 6600-01 and completed up to an including step I.13.
Critical Tasks:
RPV-2.3 - After DEOP 400-2, Emergency Depressurization, has been entered, an attempt has been made to open all ERVs, and less than the minimum number of available SRVs required for emergency depressurization (MNSRED) are open, alternate emergency depressurization methods are used until RPV pressure is less than the decay heat removal pressure (DHRP).
PC-1.3 - When executing DEOP 200-1, Primary Containment Control, if cannot stay inside the limits of the Pressure Suppression Pressure (PSP) limit, enter DEOP 400-2, Emergency Depressurization and blowdown the reactor.
Event No.
Malf.
No.
Event Type*
Event Description #
1 NONE N
BOP (New) - AUX POWER - Load U2 EDG on to Bus 24-1 2
NONE R
ATC REACTIVITY - Raise Power with Recirc Flow 3
WTNP C/T ATC CRS (New) - APRM - Flow Converter Failure 4
B38 C
BOP (New) - RBCCW - Pump Trip on Overcurrent 5
NII12POT C
ATC (New) - IRM - IRM Downscale 6
CIGP5AP ICGP5SP I/T BOP CRS (New) - ISO COND - Spurious Isolation, Incomplete 7
I21 M
ALL (New) - Manual Scram - Steam Leak in Drywell 8
T45 C
BOP (New) - GENERATOR - Fails to Auto Trip 9
I21 K23 K40 ADS3BBN M
ALL (New) - EMERGENCY DEPRESSURIZE - On Exceeding Pressure Suppression Pressure Due To Steam Leak inside the Drywell & Partial Loss of Ability to Spray the Drywell / Loss of Bus 23-1 and Bus 28. 2B ERV will fail to open.
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (T)ech Spec
- (New) - Event not used on previous 2 NRC Exams, (Pre) - Event used on previous 2 NRC Exams
Appendix D Scenario Outline Form ES-D-1 Event #
Description 1
AUX POWER - Load U2 EDG on to Bus 24-1:
The BOP will parallel the U2 EDG to Bus 24-1 per DOS 6600-01.
2 REACTIVITY - Raise Power with Recirc Flow:
The TSO calls and requests that the team raise load by 75 MWe. The team uses Recirc Flow to raise load per DGP 3-1.
3 APRM - Flow Converter Failure:
An APRM Flow Converter fails. The ATC will insert a Channel A 1/2 Scram as directed. Technical Specifications 3.3.1.1 Condition A, 3.3.1.1 Condition C, and TRM 3.3.a Function 1.a 3.3.1.1 Condition A.1 apply.
4 RBCCW - Pump Trip on Overcurrent:
The running RBCCW Pump trips on overcurrent. The team will start the standby RBCCW Pump.
IRM Channel 12 will fail downscale. The ATC will bypass the failed IRM and the CRS will address technical specifications.
6 ISO COND - Spurious Isolation, Incomplete:
The Isolation Condenser spuriously isolates. The 2-1301-1 valve will not close during the isolation and will have to be manually closed. Technical Specifications 3.5.3 Condition A and 3.6.1.3 Condition A apply.
7 Manual Scram - Steam Leak in Drywell:
A small steam leak in the Drywell begins. The Team manually scrams the Reactor before the automatic Scram occurs.
8 GENERATOR - Fails to Auto Trip Once the reactor is scrammed, the generator will fail to auto trip and the field breaker will open. The team will manually open the Generator GCBs from the 923-2 Panel per DOA 5600-01 or DOA 6000-01.
9 EMERGENCY DEPRESSURIZE - On Exceeding Pressure Suppression Pressure Due To Steam Leak inside the Drywell & Partial Loss of Ability to Spray the Drywell / Loss of Bus 23-1 and Bus 28:
The steam leak worsens causing Drywell pressure to rise rapidly. When the Team attempts to spray the Drywell, Div 2 Drywell Sprays are failed as part of initial setup and Bus 28 trips resulting in a loss of Div 1 Drywell Sprays. Eventually Primary Containment pressure will exceed the PSP limit and require the Team to Emergency Depressurize. 2B ERV will fail to open and the crew will have to choose an alternate depressurization method.