IR 05000263/2024004
| ML25029A173 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 01/30/2025 |
| From: | Dariusz Szwarc NRC/RGN-III/DORS/RPB3 |
| To: | Hafen S Northern States Power Company, Minnesota |
| References | |
| IR 2024004 | |
| Download: ML25029A173 (1) | |
Text
SUBJECT:
MONTICELLO NUCLEAR GENERATING PLANT - INTEGRATED INSPECTION REPORT 05000263/2024004
Dear Shawn Hafen:
On December 31, 2024, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Monticello Nuclear Generating Plant. On January 23, 2025, the NRC inspectors discussed the results of this inspection with you and other members of your staff. The results of this inspection are documented in the enclosed report.
No findings or violations of more than minor significance were identified during this inspection.
This letter, its enclosure, and your response (if any) will be made available for public inspection and copying at http://www.nrc.gov/reading-rm/adams.html and at the NRC Public Document Room in accordance with Title 10 of the Code of Federal Regulations 2.390, Public Inspections, Exemptions, Requests for Withholding.
Sincerely, Dariusz Szwarc, Chief Reactor Projects Branch 3 Division of Operating Reactor Safety Docket No. 05000263 License No. DPR-22
Enclosure:
As stated
Inspection Report
Docket Number:
05000263
License Number:
Report Number:
Enterprise Identifier:
I2024004-0061
Licensee:
Northern States Power Company, Minnesota
Facility:
Monticello Nuclear Generating Plant
Location:
Monticello, MN
Inspection Dates:
October 01, 2024, to December 31, 2024
Inspectors:
J. Kutlesa Sr. Emergency Preparedness Inspector
T. McGowan, Emergency Preparedness Inspector
C. Norton, Senior Resident Inspector
K. Pusateri, Resident Inspector
Approved By:
Dariusz Szwarc, Chief
Reactor Projects Branch 3
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Monticello Nuclear Generating Plant, in accordance with the Reactor Oversight Process. The Reactor Oversight Process is the NRCs program for overseeing the safe operation of commercial nuclear power reactors. Refer to https://www.nrc.gov/reactors/operating/oversight.html for more information.
List of Findings and Violations
No findings or violations of more than minor significance were identified.
Additional Tracking Items
None.
PLANT STATUS
The unit began the inspection period at rated thermal power. On October 21, 2024, the licensee reduced power to 95 percent to perform control rod maintenance and returned to 100 percent.
On December 10, 2024, the licensee reduced power to 33 percent for condenser water box cleaning and returned the unit to 100 percent on December 12, 2024. The unit remained at or near rated thermal power for the remainder of the inspection period.
INSPECTION SCOPES
Inspections were conducted using the appropriate portions of the inspection procedures (IPs) in effect at the beginning of the inspection unless otherwise noted. Currently approved IPs with their attached revision histories are located on the public website at http://www.nrc.gov/reading-rm/doc-collections/insp-manual/inspection-procedure/index.html. Samples were declared complete when the IP requirements most appropriate to the inspection activity were met consistent with Inspection Manual Chapter (IMC) 2515, Light-Water Reactor Inspection Program - Operations Phase. The inspectors performed activities described in IMC 2515, Appendix D, Plant Status, observed risk significant activities, and completed onsite portions of IPs. The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel to assess licensee performance and compliance with Commission rules and regulations, license conditions, site procedures, and standards.
REACTOR SAFETY
71111.01 - Adverse Weather Protection
Seasonal Extreme Weather Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated readiness for seasonal extreme weather conditions prior to the onset of seasonal cold temperatures for the following systems:
Reactor building chiller water system and EPA pumps operational for anticipated low river temperatures on November 29, 2024
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (3 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) Reactor recirculation system on October 8, 2024
- (2) Off-gas system, recombiner and holdup subsystems on October 18, 2024
- (3) Reactor core isolation cooling protected train on October 24, 2024
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated the implementation of the fire protection program by conducting a walkdown and performing a review to verify program compliance, equipment functionality, material condition, and operational readiness of the following fire areas:
- (1) West shutdown cooling area on October 9,2024 (2)125V division 1 battery room on October 10, 2024 (3)250V division 1 battery room on October 10, 2024
- (4) East shutdown cooling area on October 11, 2024
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated external flooding mitigation protections for beyond-design-basis flooding
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) Division 2 emergency diesel generator (EDG) emergency service water (ESW)heat exchanger
71111.11A - Licensed Operator Requalification Program and Licensed Operator Performance
Requalification Examination Results (IP Section 03.03) (1 Sample)
- (1) The inspectors reviewed and evaluated the licensed operator examination failure rates for the requalification annual operating exam administered from October 21, 2024, to December 09, 2024.
71111.11Q - Licensed Operator Requalification Program and Licensed Operator Performance
Licensed Operator Performance in the Actual Plant/Main Control Room (IP Section 03.01) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator performance in the control room during the main steam high flow group 1 instrument test surveillance procedure on November 20, 2024
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated simulator exercise guide (SEG) RRSS185 for crew 5 on October 31, 2024
71111.12 - Maintenance Effectiveness
Quality Control (IP Section 03.02) (1 Sample)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following structures, systems, and components (SSCs) remains capable of performing its intended function:
- (1) Added drain line to the residual heat removal service water (RHRSW) system in accordance with work order 700145119 on November 19, 2024
Aging Management (IP Section 03.03) (1 Sample)
The inspectors evaluated the effectiveness of the aging management program for the following SSCs that did not meet their inspection or test acceptance criteria:
- (1) Completed aging management walkdown for reactor recirculation system (outside of drywell) in the presence of the strategic engineer on December 16, 2024
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (2 Samples)
The inspectors evaluated the accuracy and completeness of risk assessments for the following planned and emergent work activities to ensure configuration changes and appropriate work controls were addressed:
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (4 Samples)
The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:
(1)
===501000090899 CV1478 (instrument air isolation to the drywell) opening trend time longer than expected (2)501000092314 Safe shutdown cable route (Appendix R) question (3)501000092267 reactor core isolation cooling system condensate pump discharge to rad waste open indication delayed during Inservice testing (IST)
(4)50100092992 Intakes issues & entry into A.6 (acts of nature procedure, on low river level)
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02)
=
The inspectors evaluated the following temporary or permanent modifications:
- (1) Installation and removal of a jumper while performing 0523, RWCU [reactor water cleanup] high flow and high room temperature trip unit instrument test and calibration
71111.24 - Testing and Maintenance of Equipment Important to Risk
The inspectors evaluated the following testing and maintenance activities to verify system operability and/or functionality:
Post-Maintenance Testing (PMT) (IP Section 03.01) (5 Samples)
- (1) Anticipated without SCRAM (ATWS) system B train after replacement of inverter and ground troubleshooting on October 3, 2024
- (2) Replacement of ESW 11 pump (P111A) due to low flow degradation on October 17, 2024
- (3) Traversing incore probe (TIP) system 2 after gearbox replacement on October 30, 2024
- (4) Division 2 core spray system after pump discharge relief valve replacement on November 20, 2024
- (5) Rerouting of wiring for the EDG 12 fast start relay for divisional separation on November 27, 2024
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
- (1) Reactor core isolation cooling (RCIC) condensate pump discharge valve to contaminated rad waste (CV2848) red open light slow to illuminate on November 12, 2024
Containment Isolation Valve (CIV) Testing (IP Section 03.01) (1 Sample)
- (1) Core spray 12 test return to torus (MO1750) valve manipulation on November 18, 2024
71114.04 - Emergency Action Level and Emergency Plan Changes
Inspection Review (IP Section 02.0102.03) (1 Sample)
- (1) The inspectors evaluated the following submitted Emergency Action Level and Emergency Plan changes.
- EPLAN02, Monticello Emergency Plan Annex, Rev 0
- QF0724, 10CFR 50.54(q) Review Screening Form, 2024786
- QF0724, 10CFR 50.54(q) Review Screening Form, FT2023 780
- QF0724, 10CFR 50.54(q) Review Screening Form, MT2023 778
- QF0724, 10CFR 50.54(q) Review Screening Form, MT2023 779
- QF0724, 10CFR 50.54(q) Review Screening Form, MT2023 781
- QF0724, 10CFR 50.54(q) Review Screening Form, MT2024 782
- QF0724, 10CFR 50.54(q) Review Screening Form, MT2024 783
- MONTICELLO NUCLEAR GENERATING PLANT AND PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNITS 1 AND 2 - ISSUANCE OF AMENDMENTS RE: STANDARD EMERGENCY PLAN AND CONSOLIDATED EMERGENCY OPERATIONS FACILITY (EPID L2021LLA0210), March 31, 2023 This evaluation does not constitute NRC approval.
71114.06 - Drill Evaluation
Additional Drill and/or Training Evolution (1 Sample)
The inspectors evaluated:
- (1) Licensed operator requalification including emergency classification on October 31,
OTHER ACTIVITIES
BASELINE
===71151 - Performance Indicator Verification The inspectors verified licensee performance indicators submittals listed below:
MS09: Residual Heat Removal Systems (IP Section 02.08)===
- (1) October 1, 2023, through September 30, 2024
MS10: Cooling Water Support Systems (IP Section 02.09) (1 Sample)
- (1) October 1, 2023, through September 30, 2024
71152A - Annual Follow-up Problem Identification and Resolution Annual Follow-up of Selected Issues (Section 03.03)
The inspectors reviewed the licensees implementation of its corrective action program related to the following issues:
- (1) Environmental qualification issues associated with the required activation energy of Automatic Switch Co. (ASCO) solenoid valves
71152S - Semiannual Trend Problem Identification and Resolution Semiannual Trend Review (Section 03.02)
- (1) The inspectors reviewed the licensees corrective action program to identify potential trends in motor operated valves (MOVs) failure to operate in manual that might be indicative of degradation in the MOVs ability to perform safety-related functions.
INSPECTION RESULTS
Observation: Licensee Corrective Actions Associated with Environmental QualificationASCO Activation Energy Issue 71152A On July 12, 2024, the licensee identified that a 2004 communication revised the activation energy of ASCO solenoid valves from 1.37eV to 1.0eV. This had no environmental qualification (EQ) effect on a majority of EQ solenoid valves because other, more limiting characteristics, were used in determining solenoid valve replacement frequency. However, two solenoid valves associated with the reactor building to suppression chamber vacuum breakers were determined to be overdue for replacement because of the change. The licensee performed prompt and past operability determinations and found the affected solenoid valves were and had been operable. They replaced and lowered the replacement intervals for the affected solenoid valves and updated the appropriate EQ files. Corrective actions were completed by August 26,
EXIT MEETINGS AND DEBRIEFS
The inspectors verified no proprietary information was retained or documented in this report.
- On January 23, 2025, the inspectors presented the integrated inspection results to S. Hafen, Site Vice President, and other members of the licensee staff.
- On December 20, 2024, the inspectors presented the emergency action level and emergency plan changes inspection results to G. Medina, Emergency Preparedness Manager, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
501000091798
L5313 Outlets in SHC House Do Not Work
10/31/2024
1151
Winter Checklist
104
Procedures
FPWMSR01
Seasonal Readiness Program
NH352431
(M117)
P&ID Recirc Loops Pumps and Motors Nuclear Boiler
System
NH362421
(M1161)
P&ID Jet Pump Instrumentation Nuclear Boiler System
NH36243
(M117)
P&ID Recirculation Loops Nuclear Boiler System
NH36251
(M125)
NH36252
(M126)
NH548174
P&ID Off-Gas Modification Train A Engineering Flow
Diagram Recombiner Building
NH548181
P&ID Off-Gas Modification Train B Engineering Flow
Diagram Recombiner Building
Drawings
NH548222
P&ID Off-Gas Modification Engineering Flow Diagram
Off-Gas Storage Area
B.01.0405
Reactor Recirculation System
B.02.0305
Reactor Core Isolation Cooling
B.07.02.0105
Recombiner System
Procedures
B.07.02.0205
Off-Gas Holdup System
Strategy A.302-G
Fire Zone 2G East Shutdown Cooling Area
Strategy A.302-H
Fire Zone 2H West Shutdown Cooling Area
Strategy A.307-A
Fire Zone 7A 125V Division I Battery Room
Fire Plans
Strategy A.307-B
Fire Zone 7B 250V Division I Battery Room
501000086301
Annual Exterior Flood Surveillance Discrepancies
06/04/2024
Corrective Action
Documents
501000088635
Flood Protection Feature Found Unsealed
08/07/2024
Procedures
1478
External Flood Monthly and Annual Surveillance
06/04/2024
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
1478
External Flood Monthly and Annual Surveillance
10/01/2024
147801
External Flood Five-Year Surveillance
09/17/2024
Procedures
140401
EDG ESW Heat Exchanger Performance Test
Miscellaneous
SEG RRSS185
Simulator Exercise Guide (Crew 5)
Procedures
0051
Main Steam Line High Flow Group 1 Instrument Test
501000052447
Recirc Pump Speed Indicator is Reading Lower
Than Historical Values
05/22/2021
501000052595
Recirc MG Set Tachometer Coupling is Shifting Axially
by About 1/2 Inch
05/26/2021
501000052651
Trend - Recirc MG Set Equip Issues
05/28/2021
501000088944
ECR to correct RHRSW13 Not Progressing
08/16/2024
501000093375
2/16/2024
Corrective Action
Documents
501000093391
VF4 Gaps Between Filter and Support
2/16/2024
Drawings
NH36664
(M112)
PI&D RHR Service Water and Emergency Service Water
Systems
29
CRVEFT Low Flow Test
Procedures
FPE-SE05
Strategic Engineering Walkdowns
7001318550010
Rx Recirculation System (Perform Aging Management
Walkdown)
2/16/2024
700140005010
Replace FIC9116A Manual/Auto Controller
10/08/2024
Work Orders
7001451190010
RHRSW13, Install Drain Line
11/19/2024
501000091102
P111A 11 ESW Degraded Flow
10/13/2024
501000091457
Spike in Unidentified Drywell Leakage
10/22/2024
501000091512
Change in DW Leak Rate at ACMP Limit
10/22/2024
Corrective Action
Documents
501000091551
MO2023 Packing Lessons Deep-Dive
10/24/2024
7001401230010
HPCI Steam Line Isolation Inboard Valve (MO2034,
10/24/2024
Work Orders
700145330020
P111A, Replace Pump
10/16/2024
501000090899
CV1478 Trend Time Longer Than Expected
10/09/2024
501000092267
CV - 2848 Red Light Indication Delayed
11/13/2024
501000092314
Safe Shutdown Cable Route Question
11/13/2024
Corrective Action
Documents
501000092922
Intakes Issues & Entry into A.6
2/02/2024
Drawings
NE364033A
Standby Diesel Generator Start Circuits
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
NF46111
Connection Diagram 4160V Switchgear A7, A8, A511, A610
& C565
NH 3604912
P&ID Instrument Air Reactor Building & Drywell
NX92165
Physical Schematic & Field Connections Model 999 EDG 12
25508-IA1
RCIC Quarterly Pump and Valve Tests
Procedures
25517-IA1
Instrument Air Valve Exercise
Corrective Action
Documents
501000091630
RWCU [Reactor Water Cleanup] Trip During
23 Procedure
10/25/2024
Procedures
23
RWCU High Flow and Room Temperature Trip
Unit Instrument Test and Calibration
501000060614
Housing gasket leak TIP 1 Drive Gear Box
2/17/2022
501000091749
TIP 2 Slow Drive Speed is too Fast
10/30/2024
501000092267
CV2848 Red Light Indication Delayed
11/13/2024
Corrective Action
Documents
501000092314
Safe Shutdown Cable Route Question
11/13/2024
3789
Relief Valve Test Data Sheet
Miscellaneous
ISTBasis
Pump and Valve InService Testing Program
Basis -CV2848
25508-IA1
RCIC Quarterly Pump and Valve Tests
278B
ATWSRecirc Trip for Reactor Pressure and Level Trip
4777
ATWS Panel Shutdown
B.03.0105
Core Spray Cooling System
Procedures
B.05.0305
Automated Traversing InCore Probe
7000667940020
Core Spray Test Line Return to Torus
11/18/2024
700091442
Core Spray Pump Discharge Relief Valve
11/19/2024
7001035470070
TIP 2 Detector/Drive Cable (PMT/RTS)
10/30/2024
7001433730025
10/03/2024
700145331040
ESW Pump PMT/RTS
10/17/2024
Work Orders
7001471440010
G3B, Reroute Cable ECR 601X5374 (12 EDG)
QF0724
10CFR 50.54(q) Review Screening Form
MT2023
779
QF0724
10CFR 50.54(q) Review Screening Form
MT2023
2
Calculations
QF0724
10CFR 50.54(q) Review Screening Form
MT2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
783
QF0724
10CFR 50.54(q) Review Screening Form
24786
QF0724
10CFR 50.54(q) Review Screening Form
FT2023 780
QF0724
10CFR 50.54(q) Review Screening Form1
MT2023
778
QF0724
10CFR 50.54(q) Review Screening Form
MT2023
781
Miscellaneous
MONTICELLO NUCLEAR GENERATING PLANT AND
PRAIRIE ISLAND NUCLEAR GENERATING PLANT,
UNITS 1 AND 2 - ISSUANCE OF AMENDMENTS RE:
STANDARD EMERGENCY PLAN AND CONSOLIDATED
EMERGENCY OPERATIONS FACILITY (EPID
L2021LLA0210)
03/31/2023
Procedures
EPLAN02
Monticello Emergency Plan Annex
Rev 0
Miscellaneous
SEG# RQSS184
Simulator Exercise Guide (Crew 5) - EAL Classification
Miscellaneous
QF0445
NRC and MOR Data Collection and Submittal Forms
71151
Procedures
FPRPI01
Preparation of NRC Performance Indicators
501000087690
EQASCO Activation Energy Issue
07/12/2024
Corrective Action
Documents
501000087690
EQASCO Activation Energy Issue-Closure
09/16/2024
501000087690
Past operability Review
08/22/2024
Engineering
Evaluations
501000087690
Prompt Operability Determination
07/17/2024
501000087225
MO2012 Failed to Cycle as Expected
06/28/2024
501000087255
MO2012 Failed to Cycle as Expected Root Cause
10/11/2024
501000087269
LPCI Vulnerability
06/29/2024
501000087273
Broken Spring Found in Actuator
06/29/2024
501000087285
MO2012 AsLeft Diagnostic Anomalies
06/29/2024
501000087286
Post Job Critique MO2012 Event Response
06/29/2024
501000087791
LPCI Valve Extent of Condition
07/16/2024
501000088600
MO2012 Motor Pinion May Not be Secured
08/05/2024
501000088639
MO2012 LST Discrepancy
08/07/2024
501000088681
MO2012 Set Screw
08/08/2024
501000088690
WO 700141731 MO2012 Issue
08/07/2024
Corrective Action
Documents
501000089575
Unclear LST Requirement for MO2012
09/04/2024
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
501000090123
RCE Revision Not Tracked in CAP
09/22/2024
7000899300080
06/29/2024
Corrective Action
Documents
Resulting from
Inspection
501000076674
FLEX Applicability Question on MO2012
07/01/2024
Miscellaneous
LER2024002-00
Low Pressure Coolant Injection Inoperable Due to Motor
Valve Failure
06/28/2024