ML23012A143
| ML23012A143 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 09/28/2022 |
| From: | Nuclear Management Co, Xcel Energy |
| To: | NRC/RGN-III/DORS/OB |
| Iskierka-Boggs T | |
| Shared Package | |
| ML21188A292 | List: |
| References | |
| Download: ML23012A143 (1) | |
Text
Form 3.3-1 Scenario Outline Facility:
Monticello Scenario #:
ILT-SS-62E (2022 ILT NRC Scenario 1)
Scenario Source:
New Op. Test #:
2022-301 Examiners:
Randy Baker Applicants/
Travis Iskierka-Boggs Operators:
Jon Robbins Initial Conditions:
100% Power, HPCI is OOS for Aux Oil Pump replacement, 12 Stator Water Cooling Pump is OOS for motor replacement.
Turnover:
BOP to perform Test 0010 (Reactor Scram Functional Test)
Critical Tasks:
CT-45: During failure to scram conditions with reactor power above 4.0%,
terminate and prevent injection from all sources except SBLC, RCIC, and CRD until level lowers to at least -36.
Safety Significance: To prevent or mitigate the consequences of any large irregular neutron flux oscillations induced by neutronic/thermal-hydraulic instabilities, RPV water level is lowered sufficiently below the elevation of the feedwater sparger nozzles. This places the feedwater spargers in the steam space providing effective heating of the relatively cold feedwater and eliminating the potential for high core inlet subcooling. For conditions that are susceptible to oscillations, the initiation and growth of oscillations is principally dependent upon the subcooling at the core inlet; the greater the subcooling, the more likely oscillations will commence and increase in magnitude.
Applicability: C.5-2007 conditions where power remains above 4.0% following the tripping of both recirc pumps.
Performance Indicator: When an ATWS occurs and reactor power remains above 4.0%
then perform RPV level reduction to at least -36. If the ATWS occurs at 100% power with NO Control Rod movement coincident with a Group 1 isolation, then level reduction must commence within 90 seconds following MSIV closure.
Distinguishable Cue: APRMs indicate reactor power above 4.0% with RPV level indicated above -36 on Panel C-05: CRS directs systems to be prevented per C.5-3205.
Performance Feedback: APRMs indicate lowering power as level is lowered to -36.
CT-47: During failure to scram conditions with a critical reactor, insert control rods using one or more methods contained in C.5-3101 to achieve reactor shutdown under all conditions (all rods inserted to at least 02).
Safety Significance: Achieving Rx shutdown is one of the primary goals of C.5-2007.
Applicability: C.5-2007 conditions with a critical reactor where one or more of the methods contained within C.5-3101 would be successful in achieving reactor shutdown.
Performance Indicator: Performance of actions in C.5-3101 is successful in shutting down the Reactor under all conditions without boron.
Distinguishable Cue: Failure of control rods to insert from a reactor scram and direction from the CRS to perform C.5-3101.
Performance Feedback: All rods in condition indicated from the RWM and Full Core Display on Panel C-05.
Event No.
Malf.
No.
Event Type*
Event Description 1
03-S36-06 BOP-N CRS-TS NP2 The BOP will perform Test 0010. During the performance of Part D, the B RPS manual scram pushbutton will fail to work. The CRS will evaluate TSs for a faulty pushbutton. The BOP will insert a half scram.
2 FW20A OATC-C OATC-MC The A MFRV will lockup. The OATC will take manual control of the B MFRV and further action to unlock the A MFRV and restore RPV Water Level Control to automatic.
3 MC04B BOP-C The A SJAE steam supply PCV will fail closed. The BOP will coordinate with the TB operator and will take manual action in the Control Room to restore steam and reset the air ejector.
4 MC03 OATC-R While the BOP is restoring the SJAE, degrading condenser vacuum will force the OATC to reduce Recirc flow to maintain condenser vacuum.
5 01-S070-04 BOP-C CRS-TS NP2 The #14 RHR pump will inadvertently start. The BOP will take manual action to secure the pump. The CRS will evaluate multiple Tech Specs for an inoperable RHR pump coincident with HPCI OOS.
6 EG02A N/A With 12 Stator Water Cooling pump OOS, the 11 Stator Water Cooling pump will trip resulting in a complete loss of Stator Water Cooling. No action can be taken for the Stator Water cooling system. The crew will be forced to insert a reactor scram.
7 CH16 Major CT-45 CT-47 When the reactor is scrammed, multiple control rods will fail to insert. The crew will take action IAW the Failure to Scram procedure to lower power and insert control rods.
8 SL01A/
B OATC-C OATC-MC Post When the OATC initiates SBLC, the first SBLC pump will fail to start. The OATC will take action to start the other SBLC pump.
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control (NP2) Not on Previous two NRC Exams
Form 3.3-1 Scenario Outline Facility:
Monticello Scenario #:
ILT-SS-63E (2022 ILT NRC Scenario 2)
Scenario Source:
New Op. Test #:
2022-301 Examiners:
Randy Baker Applicants/
Travis Iskierka-Boggs Operators:
Jon Robbins Initial Conditions:
Plant startup with reactor power at ~38%
12 Steam Packing Exhauster and 12 Stator Cooling Water pump OOS Turnover:
BOP - Place 2nd MFRV in service and place RPV level in 3-element OATC - Raise reactor power from 40% to 45% with Recirc flow Critical Tasks:
CT-10: Manually scram the reactor within 5 minutes if a design basis earthquake has occurred and has been verified by:
All three Panel C-06 earthquake annunciators in alarm And One of the following:
o Actually having felt the indications OR o
By confirmation from outside agencies.
Safety Significance: If a design basis earthquake has occurred as indicated by all three alarms and has been verified, plant operation should not continue. A Reactor Scram is required because the plant systems are not analyzed for operation at or above the design basis earthquake levels.
Safety system degradation may occur from continued operation with these conditions that could challenge the ability to protect the health and safety of the public.
Applicability: Design basis earthquake has occurred.
Performance Indicator: Upon confirmation that a design basis earthquake exists, AND with indications in the Control Room of degradation to plant safety, manually scram the Reactor.
Distinguishable Cue: Annunciators 6-C-8 (Earthquake), 6-C-13 (Operational Basis Earthquake),
and 6-C-18 (Design Basis Earthquake) in alarm and report from PI or the US Geological Survey National Earthquake Information Center.
Performance Feedback: Normal control rod insertion from the manual scram.
CT-21: When systems required to maintain core submergence do not automatically start, manually align injection systems prior to RPV level dropping below -126 (TAF).
Safety Significance: Submergence is the preferred method for cooling the core. All fuel nodes are then assumed covered with water and heat is removed by boiling heat xfer.
Applicability: C.5-1100 conditions where injection systems could otherwise maintain RPV level above -126.
Performance Indicator: When an injection system has failed to automatically start from a valid initiation signal, manually start systems as required and commence injection to avoid RPV level lowering below -126.
Distinguishable Cue: Annunciator 3-A-38 (Reactor Low Low Level) and/or 5-B-28 (Drywell Hi Press Scram Trip) is in alarm and other indications exist on the panels that the injection system should have automatically started.
Performance Feedback: Performance of procedure actions results in the system injecting into the RPV and RPV level is rising.
Event No.
Malf.
No.
Event Type*
Event Description 1
N/A BOP-N NP2 BOP will place the remaining B MFRV in service using the B manual procedure as directed by 2167 (Plant Startup).
2 N/A OATC-R The OATC will continue with the startup by raising recirc flow so reactor power rises from ~38% to ~45%.
3 02-S35-01 OATC-C When B Recirc Pump is first raised the scoop tube will lock. The OATC will take action to unlock the scoop tube.
4 CH06
_058 OATC-C CRS-TS NP2 Control Rod 14-24 will experience a seal failure causing it to drift in from position 48. The OATC will manually insert and disarm the control rod.
The CRS will evaluate Tech Specs for an inoperable control rod.
NOTE: If no action is taken, the control rod will stick at position 20 creating an unbalance flux forcing the control rod insertion.
5 RC02 BOP-C, MC CRS-TS RCIC will inadvertently auto initiate. The BOP will take manual action to secure the system. The CRS will evaluate Tech Specs for RCIC inoperable.
6 C C13 C C18 SW03 A
BOP-C, MC CT-10 An Operational Basis earthquake will cause 11 Service Water pump to trip. The 12 Service water pump will fail to auto start requiring the BOP to manually start it. Shortly after 12 Service Water pump is started and verified running, a Design Basis earthquake will occur requiring a manual reactor scram.
7 RR01 A
ED12 Major OATC-MC CT-21 NP2 Following the scram, a small LOCA and LOOP will occur. HPCI will fail to automatically start on an ECCS initiation and RCIC will be terminated from Event 5. The OATC will manually start HPCI and/or restore RCIC to maintain RPV level above TAF.
8 05-S106-2 Post BOP-C, MC NP2 Following the LOCA and/or LOOP, the 11 EDG-ESW Pump will fail to automatically start. The BOP will manually start 11 EDG-ESW Pump from C-08
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control (NP2) Not on Previous two NRC Exams
Form 3.3-1 Scenario Outline Facility:
Monticello Scenario #:
ILT-SS-64E (2022 ILT NRC Scenario 3)
Scenario Source:
New Op. Test #:
2022-301 Examiners:
Randy Baker Applicants/
Travis Iskierka-Boggs Operators:
Jon Robbins Initial Conditions:
90% Power, 12 CRD Pump and 12 Service Water pump are OOS for motor replacements.
Turnover:
BOP to perform Test 0141 (Reactor Building to Torus Vacuum Breaker Check)
Critical Tasks:
CT-1: Insert a Manual Reactor Scram within 5 minutes when no CRD pump is running and/or the second CRD accumulator low pressure alarm is received.
Safety Significance: If the accumulators discharge and a scram is required, the rods may not insert into the core at the required scram rate, or at all, depending on reactor pressure.
Therefore, the Operator is instructed to scram the reactor after receipt of the second accumulator low pressure alarm. Failure to do so may result in fuel damage from an unanalyzed rod pattern and higher than normal release to the environment.
Applicability: No CRD pumps running and a second accumulator low pressure alarm is received.
Performance Indicator: With indications of no CRD pumps running and two accumulator low pressure alarms received, Reactor scram is inserted.
Distinguishable Cue: Annunciator 5-B-17 (Charging Water Lo Press) in alarm, no CRD pump running, and at least two accumulator low pressure alarms active.
Performance Feedback: Normal control rod movement from insertion of the manual reactor scram.
CT-33: When a primary system is discharging into the secondary containment through an unisolable break, perform an Emergency Depressurization within 15 minutes when max safe operating values are exceeded in two or more areas.
Safety Significance: Should secondary containment temperatures, radiation levels or area water levels exceed their maximum safe operating values in more than one area, the RPV must be depressurized to preclude further degradation. RPV depressurization places the primary system in its lowest possible energy state, rejects heat to the suppression pool in preference to outside the containment, and reduces the driving head and flow of primary systems that are unisolated and discharging into the secondary containment. The criteria of two or more areas specified identifies the rise in secondary containment parameters as a wide-spread problem which may pose a direct and immediate threat to secondary containment integrity, equipment located in the secondary containment, and continued safe operation of the plant.
Applicability: C.5-1300 conditions when the plant is at power and a primary system is discharging into the secondary containment which can NOT be isolated resulting in two or more areas above max safe.
Performance Indicator: Upon confirmation that max safe operating values were exceeded in two or more areas, perform an emergency depressurization. This includes the opening of ADS valves. An alternative strategy would be to anticipate the blowdown by fully opening turbine bypass valves. If the blowdown is avoided by performing an anticipation of the blowdown then this would be considered successfully meeting the critical task.
Distinguishable Cue: Indications from SPDS and from back panel recorders/monitors show two areas above max safe.
Performance Feedback: RPV pressure lowering with ADS valves open.
Event No.
Malf.
No.
Event Type*
Event Description 1
02-S74-02 BOP-N CRS-TS BOP will perform Test 0141. The second vacuum breaker tested will fail open. The CRS will evaluate Tech Specs for an inoperable vacuum breaker.
2 02-A11P1-U CRS-TS 11 Recirc pump will runback to ~30% speed. The OATC may attempt to insert a scoop tube lock but it will be unsuccessful.
The CRS will evaluate TSs for mismatched recirc flows.
3 02-A11P1-U OATC-R The recirc pump runback will place the plant in the unanalyzed region of the P-F map. The OATC will insert rods to exit this region.
4 SW01A BOP-C BOP-MC NP2
- 11 RBCCW pump will trip and the #12 RBCCW pump will fail to auto start. The BOP will manually start #12 RBCCW Pump.
5 CH07B OATC-C OATC-MC The A CRD Flow Control valve will fail closed. The OATC will take manual control and swap to the standby B CRD Control valve.
6 CH08A CT-1 NP2 Once the standby flow control valve is in service, the remaining 11 CRD Pump will trip requiring the crew to insert a manual reactor scram due to 12 CRD pump being OOS.
7 RC07 Major CT-33 NP2 Following the scram a steam line break will occur in the RCIC room. Temperatures and radiation levels will rise and eventually reach two Max Safe values. The crew will be forced to perform and Emergency Depressurization.
8 CH22 OATC-C OATC-MC OATC-Post NP2 When the reactor is scrammed, the Scram Discharge Volume (SDV) will fail to automatically isolate. The OATC will manually isolate the SDV.
9 01-S053-01 BOP-C BOP-Post When the Blowdown is initiated, the C ADS SRV will fail to open.
The BOP will open an additional SRV until 3 SRVs are verified open.
- (N)ormal, (R)eactivity, (I)nstrument, (C)omponent, (M)ajor, (TS)Tech Spec, (MC)Manual Control (NP2) Not on Previous two NRC Exams (>2)