ML23150A160
| ML23150A160 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 12/08/2022 |
| From: | Constellation Energy Generation |
| To: | NRC/RGN-III |
| Bruce Bartlett | |
| Shared Package | |
| ML19121A198 | List: |
| References | |
| Download: ML23150A160 (1) | |
Text
Facility:
Byron Station Scenario #: N22-1 Scenario Source:
Op. Test #: 2022-301 Examiners:
Applicants/
Operators:
Initial Conditions:
IC 71 100% RTP, MOL, steady state conditions Turnover:
Maintain power operations. Perform 1BOSR 0.5-2.AF.1-1 for post maintenance testing following repairs. 1A FW Pump OOS. Expected return to service is 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />.
Critical Tasks:
CT Isolate Main Turbine from SG during ATWS CT Insert negative reactivity into the core during ATWS Event No.
Malf. No.
Event Type*
Event Description 1
None N
(BOP, US)
Perform 1BOSR 0.5-2.AF.1-1 Unit One Train A Auxiliary Feedwater Valves Stroke Test (21 NRC) 2 IMF CV17 I
(ATC, US)
VCT level channel 1LT-185 fails high 3
PA0005 TS (US) 1A MSIV low pressure annunciator alarms 4
IOR ZDI0PBCW03PA ON C
(BOP, US) 0A CW M/U Pump spuriously trips 5
TH11A C, TS (ATC, US)
PZR PORV leaking (Isolable) (NRC Exam 21-1) 6 IMF FW35A C
(BOP, US) 1A HD pump trips 7
IMF FW35B R
(ATC, BOP, US) 1B HD pump trips; runback required 8
[CT]
IMF TH16A IMF RP02A (preload)
IMF RP02B (preload)
IMF RD09 8 M
C, MC (ATC) 1C HD trip ATWS occurs as RX trip breakers will fail to open on manual actuation Rod speed failure occurs during ATWS limiting auto rod speed to 8 steps per minute 9
[CT]
IMF TC03 (preload)
IMF RP09A C, MC (BOP)
Turbine fails to trip in auto (21 NRC)
Spurious FWI isolation occurs with attempt to manually trip the RX (21 CERT)
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control
Critical Tasks:
- 1. CT-50 Isolate Main Turbine from SGS During ATWS Initiating Cue:
All governor and Throttle valves open, indicating Green on Ovation Panel 5501, with RX trip signal present greater than 30% reactor power.
Performance Feedback:
Valve position indication that all Governor and Throttle valves are closed.
Success Path:
Manipulations of controls to trip the main turbine with either the control board pushbutton or use of the soft keys on the Ovation panel 5502 to initiate a Turbine trip.
Measurable Performance Standard:
Manually trip the turbine from the control room prior to reaching SG levels for entry into 1BFR H.1 RESPONSE TO LOSS OF SECONDARY HEAT SINK of 10% on all SG narrow range levels. (K/A:
EPE 029EA1.19; importance - 3.6).
- 2. CT-52 Insert negative reactivity into the core Initiating Cue:
ATWS in progress with control rods inserting at less than 48 steps per minute in automatic.
Performance Feedback:
Manually inserting rods in manual until RX trip and bypass breakers open, RX power less than 5%,
constant negative IR startup rate, and/or all DRPI indications show rod at bottom indicating the RX tripped.
Success Path:
Manipulation of control rods to insert at maximum speed in manual.
Measurable Performance Standard:
Manually insert control rods within one minute and continue until the RX is verified tripped in 1BFR S.1 RESPONE TO NUCLEAR POWER GENERATION/ATWS UNIT 1, Step 6 (K/A: EPE 029EA1.20; importance - 4.0).
Scenario N22-1 Summary The scenario will start with at Full Power, MOL, steady state conditions. The crew will be turned over the activity to perform a stroke test of 1AF013B following maintenance. 1A FW Pump is OOS and is expected to be returned to service in 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br />.
Event 1 Perform 1BOSR 0.5-2.AF.1-1 The crew will perform a partial surveillance of 1BOSR 0.5-2.AF.1-1 Unit One Train A Auxiliary Feedwater Valves Stroke Test to stroke 1AF013B. This will require a logbook entry into TS 3.7.5 Auxiliary Feedwater System for closing 1AF013B. Once complete with the stroke of 1AF013B, at lead examiner discretion, continue to Event 2.
Event 2 1LI-185 fails high 1LI-185 Volume Control Tank (VCT) Level Channel 1 will fail high. The crew will identify the failure and respond to BAR 1-9-A2. The crew should enter 1BOA INST-2 OPERATION WITH A FAILED INSTRUMENT CHANNEL, perform attachment V, and swap channels in Ovation to 1LT185 VCT Level Channel 2, placing 1CV112A Letdown Diversion to VCT or HUT Tanks Valve to manual and selecting HUT or VCT to control level as required. Once the VCT level is under control, at lead examiner discretion, continue to Event 3.
Event 3 1A MSIV low pressure alarm Annunciator 1-1-B5 MSIV 1A HYD/PNEU PRESS HIGH LOW will alarm. SER point 0005 will indicate that the Active Train accumulator has a low pressure. The crew will dispatch an Equipment Operator (EO) to locally determine the accumulator pressure. After 2 minutes, the EO will report accumulator pressure of 4750 psig. The Unit Supervisor (US) will enter TS 3.7.2 MAIN STEAM ISOLATION VALVES due to the low pressure of the accumulator. Once the US has identified the TS entry and notified the Shift Manager (SM), at lead examiner discretion, continue to Event 4.
Event 4 0A CW M/U Pump trip 0A CW Makeup Pump will spuriously trip. The BOP will refer to BAR 0-38-A11 and start the standby 0B CW Makeup Pump per BOP CW-9, Circulating Makeup Pump Start-up. The crew may also enter 0BOA SEC-11, Inadequate Circulating Water Makeup. Once the 0B CW Makeup Pump has started, at lead examiner discretion, continue to Event 5.
Event 5 PZR PORV leaking (Isolable) 1RY456 U1 Pressurizer PORV will start to leakby at 5 GPM. The crew will identify the leakage, by Dual Indication on the valve and rising tailpipe temperature. The crew will respond per BAR 1-12-C6 PZR PORV DSCH TEMP HIGH. The ATC will close PZR PORV Block valve 1RY8000A to isolate the leakage. The crew will enter Tech Spec 3.4.11 Condition B. Once the Tech Spec has been entered, at lead examiner discretion, continue to Event 6.
Event 6 1A HD Pump Trip 1A HD Pump will trip. 1C HD Pump will start when crew attempts to manually start the pump per the BAR 1-17-D2 HD PUMP TRIP. The crew will execute 1BOA SEC-1 SECONDARY PUMP TRIP. After the crew stabilizes the unit and dispatches operators to perform BOP HD-1 HEATER DRAIN SYSTEM STARTUP and/or BOP HD-2 HEATER DRAIN SYSTEM SHUTDOWN, at lead examiner discretion, continue to Event 7.
Event 7 1B HD Pump Trip
1B HD Pump will trip. The crew will perform a HD Pump Runback of the unit at 20MW/min down to 780 MWe per 1BOA SEC-1 SECONDARY PUMP TRIP. After the crew stabilizes the unit at the new power level, the lead examiner will direct continuation to Event 8 & 9.
Event 8 & 9 1C HD Pump Trip and Reactor Trip Complications (ATWS) 1C HD Pump will trip. Loss of all HD pumps requires a manual RX trip per 1BOA SEC-1 Attachment D. The Reactor will NOT Trip on a manual actuation (RX Trip breakers will fail to open on a Manual or Automatic Trip) and the crew will implement 1BFR-S.1, RESPONSE TO NUCLEAR POWER GENERATION/ATWS. Control rod speed will fail to 8 steps per minute in automatic requiring the operator to manually insert control rods. A spurious Feedwater Isolation will occur shortly after the attempt to manually trip the reactor. The Turbine will NOT Trip in automatic and will require a manual actuation to trip. The local operator, when dispatched, will locally Trip the Reactor Trip Breakers in 2 minutes. The crew will then return to 1BEP-0, REACTOR TRIP OR SAFETY INJECTION. The scenario is complete when the crew has identified the Safety Injection and continues with 1BEP-0 and the US directs performance of 1BEP-0 Attachment B.
Facility:
Byron Station Scenario #: N22-2 Scenario Source:
Op. Test #: 2022-301 Examiners:
Applicants/
Operators:
Initial Conditions:
IC 72 Unit 1 is operating at 84.0% power due to Advanced Nuclear Dispatch, MOL, 875 ppm boron, equilibrium xenon Turnover:
The shift manager requests the BOP to perform RV/IV quarterly surveillance per 1BOSR 3.g.3-1. 1A SI pump is running on recirculate pending completion of vibration testing. Generation Dispatch has alerted Byron Station of potential grid stability issues.
Critical Tasks:
CT Manually actuate Main Steamline Isolation CT Isolate faulted SG Event No.
Malf. No.
Event Type*
Event Description 1
None N
(BOP, US)
Perform 1BOSR 3.g.3-1 Unit One Reheat and Intercept Quarterly Surveillance (21 NRC) 2 MF CV03 C, TS (BOP, US)
SI Pump seal leak 3
None R
Generation Dispatch request Unit 1 lower power 50 MWe within 30 minutes (C22 - modified) 4 ZDI1CV110B C, MC (ATC, US) 1CV110B Boric Acid Blender to Charging Pumps valve fails to open (Cert 21) 5 MF CH03D C
(BOP, US) 1D CRDM Exhaust Fan trips (21 NRC) 6 MF MS04B 100 MF PB2411 ON ZLO1MS018B2 ON C, MC, TS (BOP, US) 1B SG PORV will spuriously open in auto with PORV low fluid level alarm (21 CERT) 7
[CT]
MF MS08D M
Steam break outside of CNMT (21 NRC) 8
[CT]
MF MS01A MF MS01B MF MS01C MF MS01D C, MC (ATC, US)
MSIVs fail to close in Auto 1C MSIV fails to close in auto or manual
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control
Critical Tasks:
- 1) CT-12 Manually actuate Main Steamline Isolation Initiating Cue:
Indication that a main steamline isolation is required and indication that an automatic main steamline isolation did not occur.
Performance Feedback:
Valve position indication that all main steamline isolation valves are closed.
Success Path:
Manipulations of controls required to actuate main steamline isolation.
Measurable Performance Standard:
Manually actuate main steamline isolation before meeting conditions to enter 1BFR S.1 Response to Nuclear Power Generation (Intermediate Range SUR positive) or 1BFR P.1 Response to Imminent Pressurized Thermal Shock Condition (temperature drop of greater than 100°F in ALL RCS Cold Legs and ALL RCS Cold Legs less than 240°F). (K/A number: EPE 040AA1.01; importance - 4.3).
- 2) CT-17 Isolate Faulted SG Initiating Cue:
Steam pressure and flow rate indications that make it possible to identify a single SG as faulted AND valve position and flow rate indication that AFW continues to be delivered to the faulted SG.
Performance Feedback:
Any depressurization of intact SGs stops and AFW flow rate indicates zero to faulted SG.
Success Path:
Manipulate controls to isolate the faulted the SG by MSIVs indicate closed, feedline isolation valves closed, and indication of AFW flow to the faulted SG is stopped.
Measurable Performance Standard:
Isolate the faulted 1C SG before transition out of 1BEP-2. (K/A number - APE 040-AA1.03 importance -
3.9).
Scenario N22-2 Summary The scenario will start with Unit at 84% power, MOL, steady state conditions. The crew will have a turnover item to perform a partial RV/IV quarterly surveillance per 1BOSR 3.g.3-1. 1A SI pump is running on recirculate pending completion of vibration testing. Generation Dispatch has alerted Byron Station of potential grid stability issues.
Event 1 Perform 1BOSR 3.g.3-1 Unit One Reheat and Intercept Quarterly Surveillance The crew will perform a partial surveillance of 1BOSR 3.g.3-1 Unit One Reheat and Intercept Quarterly Surveillance to stroke 1MS5001A and 1MS5003A (Step F.1.b). Once complete with the stroke of 1MS5001A and 1MS5003A, at lead examiner discretion, continue to Event 2.
Event 2 1A SI Pump Seal Leak The crew will be notified by personnel in the field that the 1A Safety Injection Pump, running on recirc, has developed a seal leak and is spraying water in the room. The crew will determine that the pump needs to be secured and enter T.S 3.5.2 for the pump inoperability. Once the pump is secure and the T.S. determined, continue to Event 3.
Event 3 Generation Dispatch request Unit 1 to lower power Generation Dispatch will call the unit and direct a reduction of power of 50 MWe within 30 minutes.
The crew will perform a rapid down power. Expectations are to initiate the ramp within 10 minutes and complete within the directed time frame. Once sufficient observation of the reactivity maneuver is complete, at the lead examiner discretion, continue to Event 4.
Event 4 1CV110B Boric Acid Blender to Charging Pumps valve fails to open During boration operations, the 1CV110B Boric Acid Blender to Charging Pumps valve will fail to open as identified by valve position and Annunciator 1-9-A6 BA FLOW DEVIATION. The ATC will identify the lack of boration flow, reference the BAR, and manually open 1CV110B to initiate boration flow. Once boration flow is established sufficient observation of the reactivity maneuver is complete, at the lead examiners discretion, continue to Event 5.
Event 5 1D CRDM Exhaust Fan trips 1D CRDM Exhaust Fan trips. The BOP will refer to BAR 0-33-A5 and start an additional CDRM Fan per BOP VP-9. Once the BOP has started another CRDM Exhaust Fan, at lead examiner discretion, continue to Event 6.
Event 6 1B SG PORV will spuriously open in AUTO with PORV low fluid level alarm 1B SG PORV will start ramping open over a period of one minute. The BOP will manually close valve. The valve will not indicate completely closed and Unit Supervisor will determine TS 3.7.4 and T.S.3.6.3 applies. The crew will direct isolating the SG PORV using manual isolation valve 1MS019B.
Event 7 & 8 Steam Break outside of CNMT and MSIVs fail to close in Auto A steamline break will occur on 1C Mainsteam line outside of CNMT between the Containment wall and the 1C MSIV. The crew will identify the steamline break and initiate a manual RX Trip and actuate MS Isolation. The crew will enter 1BEP-0, REACTOR TRIP OR SAFETY INJECTION.
The crew will initiate a manual Safety Injection, if an automatic one has not occurred. The Crew will transition to 1BEP-2 FAULTED STEAM GENERATOR ISOLATION. The crew will identify that the MS Isolation valves failed to closed in automatic and initiate a MS Isolation via a MCB control switch. 1C MSIV will remain open. The scenario is complete when the crew has transitioned from 1BEP-2 to 1BEP ES-1.1 SI TERMINATION UNIT 1 and the 1C SG is isolated.
Facility:
Byron Station Scenario #:
N22-3 Scenario Source:
Op. Test #:
2022-301 Examiners:
Applicants/
Operators:
Initial Conditions:
IC 73, Unit 1 is at 55%, steady state, Equilibrium Xenon, BOL. On-line risk is green.
Turnover:
Unit 1 is at 55%, steady state, Equilibrium Xenon, BOL. On-line risk is green.
Following turnover, the Unit 1 SX pumps will be swapped per BOP SX-9 to allow for Unit 2 surveillance testing. EOs are briefed and standing by for the SX pump swap. 1B CW Pump OOS, expected restoration is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
Critical Tasks:
CT Isolate ruptured Steam Generator CT Stop RCS Cooldown Even t No.
Malf. No.
Event Type*
Event Description 1
None N
(BOP, US)
Swap Unit 1 SX pumps 2
Smart Scenario Actions C, MC (ATC, US) 1CV121 fails open 3
IMF PB2198 ON IMF FW44 TS (US) 1B AF pump local alarm (Air Box Trip) (21 CERT) 4 Smart Scenario Actions C, MC (ATC, US) 1RY455C drifts partially open (19-2 NRC -
modified) 5 IMF SW01B IMF SW01A IRF SW07 100 C, TS (BOP, US) 1B SX pump trip with 1A SX pump failure to manually start Opens 2SX005 6
None R
Tech Spec 3.0.3 Ramp (19-2 NRC) 7 IMF TH03B
[CT]
[CT]
M (ATC, BOP, US) 1B Steam Generator Tube Rupture (21 NRC) 8 TH11B C, MC (ATC, US) 1RY456 fails open 9
ZDI1CV8100 C, MC (BOP) 1CV8100 fails to close with Phase A coincident with the SI
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control
Critical Tasks:
- 1) CT-18 Isolate ruptured SG Initiating Cue:
Indication and /or annunciation of SGTR in one SG by increasing water level or radiation, and indication and/or annunciation of a reactor trip, and indication and/or annunciation of SI.
Performance Feedback:
Indication of stable or increasing pressure or indication of decreasing or zero feedwater flow rate in the ruptured SG.
Success Path:
Manipulation of controls as required to isolate the ruptured SG.
Measurable Performance Standard:
Close 1B MSIV prior to initiating RCS Cooldown (K/A: 035A4.06; importance 4.2)
- 2) CT-54 Stop RCS cooldown Initiating Cue:
An operator-initiated cooldown is in progress following a SGTR AND indication of SGTR in a previously intact SG.
Performance Feedback:
Indication of stable RCS temperature, indication of stable of increasing pressure in the intact SG(s),
or indication of stable or increasing pressure in the newly ruptured SG Success Path:
Manipulation of controls as required to stop the operator initiated RCS cooldown.
Measurable Performance Standard:
Stop RCS depressurization prior to a transition to BCA-3.1 SGTR WITH LOSS OF REACTOR COOLANT SUBCOOLED RECOVERY DESIRED occurs. (K/A: EPE 038EA1.30; importance - 4.0/3.8).
Scenario N22-3 Summary The scenario will start with Unit 1 is at 55%, steady state, Equilibrium Xenon, BOL. On-line risk is green. Following turnover, the Unit 1 SX pumps will be swapped per BOP SX-9 to allow for Unit 2 surveillance testing. EOs are briefed and standing by for the SX pump swap. 1B CW Pump OOS, expected restoration is 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.
Event 1 Swap SX pumps per BOP SX-9 After completing shift turnover and relief, the crew will perform BOP SX-9 SWITCHING A STANDBY ESSENTIAL SERVICE WATER PUMP WITH AN OPERATING ESSENTIAL SERVICE WATER PUMP to swap Unit 1 SX pumps. The BOP will swap SX pumps by starting the 1B SX pump, then stopping the 1A SX pump using peer checks as appropriate.
Event 2 1CV121 fails open 1CV121 will fail to operate in auto. The valve will fail open, and annunciator 1-9-D3 CHG LINE FLOW HIGH LOW will be lit. The ATC will announce the failure and take manual control of 1CV121 to maintain pressurizer level. Once manual control of pressurizer level is established and with chief examiner discretion, continue to event 3.
Event 3 1B AF pump local alarm (Air Box Trip)
A trouble alarm will come in for the 1B AF Pump. The crew will dispatch an EO to the 1B AF pump. The EO will report that the 1B AF Pump Air Box Tripped annunciator is in alarm on the local control panel. The airbox trip lever will not reset. The SRO will enter Tech Spec 3.7.5 Condition A for the 1B AF pump. Once the US has determined the Tech Spec requirements, at lead examiner discretion, continue to Event 4..
Event 4 1RY455C drifts partially open 1RY455C will fail slowly open. This will cause PZR Pressure to slowly drop. The ATC will respond using BHC-1-RY-P PRESSURIZER PRESSURE MALFUNCTION. The ATC will take manual control of the spray valve and close it. The ATC is anticipated to control Pressurizer Pressure in automatic with the 1RY455B. Once the ATC has closed 1RY455C and has control of RCS pressure, at lead examiner discretion, continue to Event 5.
Event 5 1B SX pump trip with 1A SX pump failure to manually start Once BOP SX-9 is complete, the 1B SX pump will trip and the 1A SX pump will fail to start. The SRO will direct the BOP to respond to the SX pump trip per BHC 1-2-A1. The BOP will attempt to start the 1A SX pump, but the 1A SX pump will not start. The BOP will continue the prompt response actions and request Unit 2 to crosstie SX between the units. The crew will dispatch an EO to investigate the 1A and 1B SX pump trips. The SRO will enter Tech Spec 3.7.8 Condition A for both SX pumps and LCO 3.0.3. The crew will brief and begin to shutdown the unit.
Event 6 Tech Spec 3.0.3 Ramp The crew will perform a Reactivity Brief for a Unit Shutdown. This will be accomplished per BGP 100-4 or 1BGP 100-4T2. The US may request guidance from the Shift Manager on whether to ramp immediately, as the TS 3.0.3 actions allow for an hour to take action and up to an additional 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to be in Mode 3.
Events 7, 8 & 9 Steam Generator Tube Rupture, 1RY456 PZR PORV fails open, and 1CV8100 fails to close on Phase A A 600 gpm tube rupture will occur on 1B Steam Generator. The crew will identify the ruptured SG and initiate a manual RX Trip, enter 1BEP-0 REACTOR TRIP OR SAFETY INJECTION UNIT 1, and manually actuate a Safety Injection, if auto Safety Injection has not yet occurred depending on timing of crew actions. The crew will transition to 1BEP-3 STEAM GENERATOR TUBE RUPTURE at Step 13 of 1BEP-3. 1CV8100 will fail to close on the Phase A signal generated coincident with the Safety Injection. 1CV8100 will need to be closed in manual per 1BEP-0 Attachment B. The 1RY456 will fail open during the depressurization of the RCS. The crew will close the 1RY456 with the C/S prior to entering 1BCA 3.1.
The scenario can be terminated when the crew Stops the depressurization per 1BEP-3 Step 13 or transitions to 1BCA-3.1.