IR 05000282/2025001
| ML25125A141 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/05/2025 |
| From: | Dariusz Szwarc NRC/RGN-III/DORS/RPB3 |
| To: | Paulhardt W Northern States Power Company, Minnesota |
| References | |
| IR 2025001 | |
| Download: ML25125A141 (1) | |
Text
SUBJECT:
PRAIRIE ISLAND NUCLEAR GENERATING PLANT - INTEGRATED INSPECTION REPORT 05000282/2025001 AND 05000306/2025001
Dear Werner Paulhardt:
On March 31, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at Prairie Island Nuclear Generating Plant. On April 15, 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.
One finding of very low safety significance (Green) is documented in this report. This finding involved a violation of NRC requirements. We are treating this violation as a non-cited violation (NCV) consistent with Section 2.3.2 of the Enforcement Policy.
A licensee-identified violation which was determined to be of very low safety significance is documented in this report. We are treating this violation as an NCV consistent with Section 2.3.2 of the Enforcement Policy.
If you contest the violations or the significance or severity of the violations documented in this inspection report, you should provide a response within 30 days of the date of this inspection report, with the basis for your denial, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; the Director, Office of Enforcement; and the NRC Resident Inspector at Prairie Island Nuclear Generating Plant.
If you disagree with a cross-cutting aspect assignment in this report, you should provide a response within 30 days of the date of this inspection report, with the basis for your disagreement, to the U.S. Nuclear Regulatory Commission, ATTN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region III; and the NRC Resident Inspector at Prairie Island Nuclear Generating Plant.
May 5, 2025 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 Nos. 05000282 and 05000306 License Nos. DPR-42 and DPR-60 Enclosure:
As stated cc w/ encl: Distribution via LISTSERV Signed by Szwarc, Dariusz on 05/05/25
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting an integrated inspection at Prairie Island 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. A licensee-identified non-cited violation is documented in report section: 71111.1
List of Findings and Violations
Failure to Adequately Assess Risk Associated with Degraded Equipment Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000282/2025001-01 Open/Closed
[H.12] - Avoid Complacency 71111.15 Inspectors identified a Green finding and associated NCV of 10 CFR Part 50, Appendix B,
Criterion V, Instructions, Procedures, and Drawings, when a known leak in the auxiliary building 11G fan coil unit degraded, spraying down the safety-related motor control center (MCC) 1LA1, causing it to fail. Specifically, the licensees leak monitoring program procedures failed to ensure that leaks in non-safety-related systems were assessed for potential impacts on safety-related equipment.
Additional Tracking Items
Type Issue Number Title Report Section Status URI 05000282/2025001-02 Failure of the 12 Residual Heat Removal Pump Mechanical Seal 71111.15 Open LER 05000306/2024-002-00 LER 2024-002-00 for Prairie Island Nuclear Generating Plant, Unit 2, Reactor Trip and Auto-Start Actuation of Auxiliary Feedwater due to High Negative Neutron Flux Rate Trip 71153 Closed
PLANT STATUS
Unit 1 began the inspection period shut down for a refueling outage. Unit 1 went critical on January 16, 2025, and power was raised to approximately 97 percent of rated thermal power (RTP). Power was maintained at approximately 97 percent RTP for troubleshooting and repairs to the leading-edge flow meter (LEFM) system. On February 9, 2025, Unit 1 reactor power was raised to full RTP and was maintained at or near RTP for the remainder of the inspection period.
Unit 2 began the inspection period at full-rated thermal power. On February 25, 2025, Unit 2 performed a rapid downpower to approximately 60 percent RTP due to the trip of a circulating water pump. Unit 2 was returned to full RTP on March 1, 2025, following restoration of the circulating water pump to service. Unit 2 remained at or near full RTP 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 on-site 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 cold weather preps/plant condition (TP 1637) for the following systems:
condensate storage and cooling water systems on January 13, 2025
Impending Severe Weather Sample (IP Section 03.02) (1 Sample)
- (1) The inspectors evaluated the adequacy of the overall preparations to protect risk-significant systems from impending severe weather, specifically extreme cold weather and AB 2 response during a week of subzero temperatures on February 18, 2025.
71111.04 - Equipment Alignment
Partial Walkdown Sample (IP Section 03.01) (4 Samples)
The inspectors evaluated system configurations during partial walkdowns of the following systems/trains:
- (1) C1.1.20.7-10 D5 diesel generator auxiliaries and local panels and switches on January 30, 2025
- (2) C1.1.20.7-12 D5 diesel generator circuit breakers and panel switches on January 30, 2025
- (3) C1.1.20.7-9 D5 diesel generator valve status, revision 18, on February 26, 2025
- (4) C1.1.20.7-13 D6 diesel generator valve status, revision 20, on March 4, 2025
71111.05 - Fire Protection
Fire Area Walkdown and Inspection Sample (IP Section 03.01) (6 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) Fire Detection Zone (FDZ) 35, battery room 21 and 22, elevation 695' on February 4, 2025
- (2) FDZ 1, turbine building, battery room 11 and 12, elevation 695' on February 4, 2025
- (3) FDZ 24, turbine building bearing protection, elevation 735', Unit 1 on January 7, 2025
- (4) FDZ 49, turbine building bearing protection, elevation 735', Unit 2 on January 7, 2025
- (5) FDZ 43, bus 111 and 121 switchgear rooms, elevation 715'-10" on February 19, 2025
- (6) FDZ 11, bus 15 and16 switchgear rooms, elevation 715' on February 19, 2025
71111.06 - Flood Protection Measures
Flooding Sample (IP Section 03.01) (1 Sample)
- (1) The inspectors evaluated internal flooding mitigation protections and the impact of degraded turbine building sump system on internal flood analysis and actions on March 3, 2025.
71111.07A - Heat Exchanger/Sink Performance
Annual Review (IP Section 03.01) (1 Sample)
The inspectors evaluated readiness and performance of:
- (1) 22 component cooling water heat exchanger performance testing on March 20, 2025
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 reactor startup from 1R34 on January 16, 2025.
Licensed Operator Requalification Training/Examinations (IP Section 03.02) (1 Sample)
- (1) The inspectors observed and evaluated licensed operator requalification as-left requalification simulator scenario on January 24, 2025.
71111.12 - Maintenance Effectiveness
Maintenance Effectiveness (IP Section 03.01) (3 Samples)
The inspectors evaluated the effectiveness of maintenance to ensure the following structures, systems, and components (SSCs) remain capable of performing their intended function:
501000088496 23 inverter maintenance rule actions on January 29, 2025 (3)501000092116 CV-31084 exceeding limit stroke time on January 29, 2025 Quality Control (IP Section 03.02)
The inspectors evaluated the effectiveness of maintenance and quality control activities to ensure the following SSC remains capable of performing its intended function:
71111.13 - Maintenance Risk Assessments and Emergent Work Control
Risk Assessment and Management Sample (IP Section 03.01) (5 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:
(1)risk associated with SPV with red rock lines 1 and 2 out of service (OOS)on January 13, 2025 (2)risk with D6 emergency diesel generator (EDG) OOS and emergent work on 2RY during cold weather on January 21, 2025 (3)risk with breaker 26-16 in pullout with the EDG available on January 28, 2025 (4)21 inverter hot spot on February 4, 2025 (5)actions associated with failed 33CR/B8 relay on February 15, 2025
71111.15 - Operability Determinations and Functionality Assessments
Operability Determination or Functionality Assessment (IP Section 03.01) (6 Samples 1 Partial)
The inspectors evaluated the licensees justifications and actions associated with the following operability determinations and functionality assessments:
(1)21 core spray pump absorbent pad caught in shaft 501000094184 on January 23, 2025 (2)13 containment fan coil unit damper failed to reposition to dome on February 6, 2025 (3)prompt operability determination (POD) for CAP 501000094563 MOLR replacement for BKR 222E-16 on February 20, 2025
- (4) POD for 501000095507 D6 diesel high temp coolant leak on February 25, 2025 (5)water leaking on MCC 1LA1 and cascaded inoperability on March 10, 2025 (6)
(Partial)12 residual heat removal (RHR) pump seal failure on January 1, 2025
- (7) D5 EDG piston and cylinder head cracks on March 5, 2025
71111.18 - Plant Modifications
Temporary Modifications and/or Permanent Modifications (IP Section 03.01 and/or 03.02) (2 Samples)
The inspectors evaluated the following temporary or permanent modifications:
- (2) TCR 602000027163, RHR Procedure Modification, on March 7, 2025
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) (7 Samples)
- (1) Surveillance Procedure (SP) 1428, PMT [post-maintenance testing] of 12 S/G Main Feed Regulating Valve on Unit 1, on January 8, 2025
- (2) PMT of 1N51 following work on the motherboard on January 11, 2025
- (3) PMT of 22 D6 room cooling fan predictive maintenance/blocking fan rotation on January 31, 2025
- (6) PMT of bus 25 source from D5 diesel gen after repair of BKR 25-2 on March 20, 2025
- (7) PMT of 122 control room chiller, per SP 1161B, Control Room Train B Chilled Water Pump Quarterly Test, revision 27, on March 26, 2026
Surveillance Testing (IP Section 03.01) (5 Samples)
- (2) SP 2003, Analog Protection Functional Test, revision 87, on February 13, 2025
- (3) WO 700137436, Safeguards Logic Test at Power Train B, revision 32, on January 3, 2025
- (5) SP 2234B, 22 Aux Feedwater Pump Suction and Discharge Pressure Switch Calibration, revision 14, on February 24, 2025
Inservice Testing (IST) (IP Section 03.01) (1 Sample)
- (1) WO 700140482, SP 2102 22 TDAFWP [turbine-driven auxiliary feedwater pump] Qtrly Test, on February 20, 2025
71114.06 - Drill Evaluation
Required Emergency Preparedness Drill (1 Sample)
(1)emergency preparedness tabletop drill on March 25,
OTHER ACTIVITIES - BASELINE
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)follow-up of D5/D6 fuel oil storage tank vault actions on January 26, 2025 (2)follow-up of reactor coolant pump casing design analysis error on January 26, 2025
71152S - Semi-annual Trend Problem Identification and Resolution Semi-annual Trend Review (Section 03.02)
- (1) The inspectors reviewed the licensees corrective action program to identify potential trends in safety injection pump oil issues on February 14, 2025, that might be indicative of a more significant safety issue.
71153 - Follow-Up of Events and Notices of Enforcement Discretion Event Report (IP Section 03.02)
The inspectors evaluated the following licensee event reports (LERs):
- (1) LER 2024-002-00 for Prairie Island Nuclear Generating Plant, Unit 2, Reactor Trip and Auto-Start Actuation of Auxiliary Feedwater due to High Negative Neutron Flux Rate Trip (Agencywide Document Access and Management System [ADAMS]
Accession No. ML24354A316). The inspectors determined that the cause of the condition described in the LER was not reasonably within the licensees ability to foresee and correct and therefore, was not reasonably preventable. No performance deficiency nor violation of NRC requirements was identified. This LER is closed.
INSPECTION RESULTS
Licensee-Identified Non-Cited Violation 71111.13 This violation of very low safety significance was identified by the licensee and has been entered into the licensee corrective action program and is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Violation: Prairie Island Technical Specification (TS) 3.1.7 Rod Position Indication [RPI],
Condition A, One RPI per group inoperable in one or more groups requires A.1 Verify the position of the rod with inoperable RPI indirectly by using core power distribution measurement information once per 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> OR A.2 Verify the position of the rods with inoperable RPI indirectly by using core power distribution measurement information within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> AND Once per 31 EFPD [Effective Full Power Days] thereafter AND 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after discovery of each unintended rod movement AND 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after each movement of rod with inoperable RPI > 12 steps AND Prior to THERMAL POWER exceeding 50% RTP AND 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> after reaching RTP OR A.3 Reduce THERMAL POWER to < 50% RTP within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Contrary to the above, from 19:23 on February 15, 2025 through 09:14 on February 16, 2025, the licensee failed to verify the position of the rod with inoperable RPI indirectly by using core power distribution measurement information, verify the position of the rods with inoperable RPI indirectly by using core power distribution measurement information, or reduce thermal power to <50% RTP. Specifically, the licensee failed to enter Condition A and complete the required ACTIONs of A.1, A.2, or A.3 within the allowed completion time.
Significance/Severity: Green. Inspectors utilized NRC Inspection Manual Chapter (IMC) 0609 Appendix A, The Significance Determination Process for Findings At-Power, and determined that the violation screened to Green based upon Exhibit 3 - Barrier Integrity Screening Questions, Section A, Fuel Cladding Integrity. The inspectors answered No to all four screening questions, resulting in the issue screening to Green.
Corrective Action References:
501000095215, IRPI Panel Maintenance 501000095225, Unclear Tech Spec Guidance 501000095401, RPI Tech Spec 501000095588, Technical Requirements Manual Guidance Failure to Adequately Assess Risk Associated with Degraded Equipment Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000282/2025001-01 Open/Closed
[H.12] - Avoid Complacency 71111.15 Inspectors identified a Green finding and associated non-cited violation of 10 CFR Part 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, when a known leak in the auxiliary building 11G fan coil unit degraded, spraying down the safety-related MCC 1LA1, causing it to fail. Specifically, the licensees leak monitoring program procedures failed to ensure that leaks in non-safety related systems were assessed for potential impacts on safety-related equipment.
Description:
On March 7, 2025, while restoring the 11 containment and auxiliary building chiller, a significant leak was reported to be spraying onto safety-related MCC 1LA1; shortly thereafter, smoke started emitting from the MCC. The MCC was deenergized, and the licensee entered the applicable limiting conditions for operation (LCO). Subsequently, the inspectors identified that the two licensee procedures utilized for leak assessment and management failed to address the risk associated with leakage from non-safety-related equipment impacting safety-related equipment. In addition, inspectors identified that the licensee was not following their process for tracking leaks on the plant status report and were not implementing the 50.59 process for catch containers left in place for >90 days.
Corrective Actions: The leak was isolated, repairs to the MCC were completed, the MCC was restored, and the licensee entered the procedural issues into their corrective action program for resolution.
Corrective Action References:
501000097064, Leak Management and Tracking 501000095933, MCC 1LA1 Deenergized due to Smoke 501000095926, Water Leak 11G Cooler Leaking on MCCs 501000097079, No 50.59s for Leak Catch Containments
Performance Assessment:
Performance Deficiency: The licensees failure to ensure that activities affecting quality were prescribed by documented instructions, procedures, or drawings and to ensure activities were accomplished in accordance with these instructions, procedures, or drawings was within the licensees ability to foresee and correct and was therefore a performance deficiency.
Screening: The inspectors determined the performance deficiency was more-than-minor because it was associated with the Procedure Quality attribute of the Mitigating Systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, due to lack of procedural guidance, the inadequate risk assessment and leak mitigation led to additional leakage from the fan coil unit, wetting a safety-related MCC which became inoperable, preventing the MCC from being able to perform its safety function. This was similar to the more-than-minor example provided in IMC 0612, Appendix E, Example 4.f.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.
Inspectors determined that the issue screened to Green by answering No to the screening questions in Exhibit 2, Mitigating Systems.
Cross-Cutting Aspect: H.12 - Avoid Complacency: Individuals recognize and plan for the possibility of mistakes, latent issues, and inherent risk, even while expecting successful outcomes. Individuals implement appropriate error reduction tools. The licensee failed to consider the inherent risk of an increase in the leak rate and the potential impact on nearby safety-related equipment.
Enforcement:
Violation: 10 CFR 50 Appendix B, Criterion V Instructions, Procedures, and Drawings, requires Activities affecting quality shall be prescribed by documented instructions, procedures, or drawings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures, or drawings. Instructions, procedures, or drawings shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished.
Contrary to the above, on March 7, 2025 the licensee failed to have documented instructions, procedures, or drawings, of a type appropriate to the circumstances and failed to accomplish quality related activities in accordance with prescribed instructions, procedures, or drawings.
Specifically, licensee procedures failed to address the risk associated with an equipment deficiency and the impact to safety-related equipment if the deficiency continued to degrade.
Additionally, the Licensee failed to follow their prescribed procedures for tracking leaks and evaluating catches left in place greater than 90 days.
Enforcement Action: This violation is being treated as a non-cited violation, consistent with Section 2.3.2 of the Enforcement Policy.
Unresolved Item (Open)
Failure of the 12 Residual Heat Removal Pump Mechanical Seal URI 05000282/2025001-02 71111.15
Description:
On December 5, 2024, the 12 RHR pump mechanical seal failed catastrophically when placing the 12 RHR pump in service during plant cooldown. This rendered the B train of RHR inoperable and unavailable, causing entry into an unplanned LCO.
Planned Closure Actions: Review the provided documentation determining the cause of the failure to determine if a performance deficiency existed.
Licensee Actions: The licensee is to provide the results of the equipment causal evaluation and the vendor failure analysis.
Corrective Action References:
501000093025, Steam from 12 RHR Pit After Pmp Start 501000093061, Mechanical Seal Leakage 501000093153, 12 RHR Pump Issue Organizational Learnings 501000094057, UA Limit Exceeded for 12 RHR Pump 501000097128, Failure Analysis for 12 RHR Observation: Follow-up of Actions Associated with Reactor Coolant Pump Technical Bulletin 71152A In January of 2022, the licensee received a Technical Bulleting (TB) TB-22-1 from their vendor, Westinghouse. While revising a design analysis for a reactor coolant pump (RCP)casing, Westinghouse identified that the legacy RCP casing design analyses of record, which are based on two-dimensional (2D) analytical methods, do not adequately represent the casing design geometry. In addition to this, it was identified that the as-analyzed casing wall thickness was non-conservative with respect to thermal stress. Westinghouse determined that there is no immediate impact on RCP operability because Westinghouse demonstrated through conservative elastic analysis that the conservative American Society of Mechanical Engineers (ASME) Code limits would not be exceeded until the plant has experienced at least 120 heat-up and cooldown cycles. Even if greater than 120 cycles are reached, this does not adversely impact RCP operability because of the conservatisms in the methodology and inputs. The licensee entered the issue into their corrective action program (CAP) and initiated Engineering Change Request (ECR) ECR 601000003567 to update the documents for RCP-allowed thermal cycles from 200 to 120 cycles. Based upon significant margin to the 120 cycles, the licensee determined that this was a low-risk item. On October 3, 2022, this action was approved as a management exception to the CAP performance indicators due to the need for a long lead time response from the vendor. Westinghouse completed a pump casing integrity evaluation in response to TB-22-1, which was uploaded to the CAP on May 22, 2024. No additional actions have been taken since then; mentoring, outage preparations, and emergent work took priority over completing document updates. However, this CAP is still listed as a management exception to the CAP performance indicators, even though the vendor response has been provided. No more-than-minor findings or violations were identified during this review.
Observation: Follow-Up of D5/D6 Emergency Diesel Generator Fuel Oil Storage Tank Vault Actions 71152A Inspectors performed follow-up of actions associated with degradation of tanks and piping within the D5 and D6 emergency diesel generator fuel oil storage tank vaults. Previous annual inspections had been documented as unsatisfactory due to moisture induced corrosion on the tanks and piping within the vaults. Additionally, the licensee had received a Green non-cited violation in 2021 (ML21314A220) in part for degraded fuel oil storage tank piping which had the potential to challenge the ability of the EDGs to meet their mission time.
Licensee actions included remediation and application of protective coatings for the degraded areas. Subsequent inspection of the fuel oil storage tank vaults in 2024 were completed satisfactorily. The inspectors did not identify any more-than-minor findings or violations during this review.
Observation: Semi-Annual Trend of 21 Safety Injection Pump Oil Issues 71152S Inspectors selected 21 safety injection pump degraded conditions to assess potential trends that might lead to a more significant issue. Inspectors reviewed CAP documents related to particulates in oil, paint chips in oil sump, cracked radial bearing, an incorrect O-ring, coupling tolerance issues, and oil leaks on housing piping. No formal causal evaluations were performed for the CAPs reviewed.
The vendor conducted an analysis of the cracked bearing. Oil and pump performance evaluations determined there was not sufficient evidence to support a particular cause, however, the vendor did support qualification and operability of the pump. Considering the O-ring, a potential nonconformance in size of the year 2005-installed O-ring was identified and corrected moving forward.
There was an as-found pump coupling tolerance issue discovered during maintenance.
No cause was identified, but the motor was magnetically re-centered with as-left tolerances within specification. Additionally, outdated drawings were resolved by the system engineer.
No discernable trends between issues could be identified. No findings or more-than-minor violations were identified during the review.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified that no proprietary information was retained or documented in this report.
- On April 15, 2025, the inspectors presented the integrated inspection results to Werner Paulhardt, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
AB-2
Severe Weather
Procedures
TP 1637
Winter Plant Operation
C1.1.20.7-10
D5 Diesel Generator Auxiliaries and Local Panels and
Switches
C1.1.20.7-12
D5 Diesel Generator Circuit Breakers and Panel Switches
C1.1.20.7-13
D6 Diesel Generator Valve Status
Procedures
C1.1.20.7-9
D5 Diesel Generator Valve Status
Fire Plans
F5 Appendix A
Appendix A Fire Strategies
Calculations
ENG-ME-759
GOTHIC Internal Flooding Calculation for the Turbine
Building
Procedures
H36
Plant Flooding
Corrective Action
Documents
SP 2304
Unit 2 Component Cooling Heat Exchanger Performance
Test
1C1.2-M1
Unit 1 Startup to Mode 1
Procedures
1C1.4
Unit 1 Power Operation
2000011201
FP-PE-SW-01; SW/MIC Program
2000015288
CAP: 501000092116, CV-31084 Exceeded Limiting
11/08/2024
2000017425
CAP 501000093425, POD 500000333194
2/20/2024
2000018581
NSPM Calculation No. 2451569.301, Prairie Island Tee Leak
N-513-5 Evaluation; EC Number 608000001259
2/20/2024
2000024617
CAP ID #501000086702, Significant Leak Out of Casing
Vent Weld
Engineering
Evaluations
2000028303
CAP #501000086702, Significant Leak Out of Casing Vent
08/28/2024
1047-02
Operations Control Room Checklist, 602000032921
2
500000330860
Maintenance Rule Functional and MSPI Failure Evaluation;
Also, Reference QIM #501000088496; Received
Unexpected Annunciator, 47505-0308 23 INVERTER INSTR
BUS III (BLUE) BYPASSED
08/03/2024
QC Inspection
Logs
QC Inspection Logs
03/07/2024 -
03/06/2025
Miscellaneous
UT Examination
Procedure: FP-PE-NDE-425, Work Scope: 2R34 MIC,
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Summary No.: 2-MIC-2151, Report No.: 2R34-MIC-003,
WO No.: MN 10314737
Procedures
FP-NO-QC-02
Inspection Planning
700083249-0010
700125804-0010
TD AFW PMP Recirc L-O CLG Line Check
700127459-0125
CPF: Install Fill Piping and Drain Valve
700135839-0005
Replace MV-32078; Sump B to 12 RHR PMP TRN B
(Outside) MV
700138704-0050
Prefab Replacement Valve RH-135-5 and Piping
700148647
D15.1 Install 11 RCP Replacement Seal
Work Orders
Work Orders
Various Work Orders
07/02/2024 -
03/06/2025
Corrective Action
Documents
500000331720
IP-01 Provide Inverters to Supply Four Channels
of Regulated 120 Vac Instrument Bus Power
11/14/2024
2000016878
Risk Informed Completion Time (RICT) Program,
FP-OP-RICT-01
2000034960
OI #25-01
01/12/2025
Procedures
Abnormal
Operating
Procedure 1C15
AOP1
Shutdown Loss of Cooling
Calculations
Calculation No.:
2008-05502
Evaluation to Justify Use of Chesterton Shaft Seals for
the RHR Pumps
501000093052
Leakage Found Around Flange
2/06/2024
501000093052
Body to Bonnet Flange on Check Valve RH-3-3 was Found
with a Leak Indication of Traces of Boris Acid
01/13/2025
501000094184
CS Pump absorbent caught in shaft
01/18/2025
501000094563
A and B Phase MOLR for Breaker PI:2 EB:BKR 222E-16, 21
PRZR LIQ SMPL ISOL MV-32409; Tripped
01/29/2025
501000094563
MOLR Replacement for BKR 222E-16
01/29/2025
Corrective Action
Documents
501000095507
Through Wall Coolant Leak
2/24/2025
Engineering
Evaluations
2000017425
CAP 501000095507; POD 500000334155; Leak on the
D6 Engine 1 High Temperature Cooling Water Pipe
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
2000017425
Leak on the D6 Engine 1 High Temperature Cooling Water
Pipe
QF1146, Past
Operability
Review
Body to Bonnet Flange on Check Valve RH-3-3 was Found
with a Leak Indication of Traces of Boric Acid
2/06/2024
Miscellaneous
Vendor Technical
Manual: XH-1-
1394
Engineering
Changes
601000005578
D5 EDG Lube Oil System Modification
03/19/2025
Engineering
Evaluations
EC
601000005578
EDG Lube Oil System Modifications
03/19/2025
Procedures
TCR
2000027163
RHR Procedure Modification
03/07/2025
Work Orders
700103871
OPS: RTS/PMT - After Repair of BKR 25-2
PI Summary
Report - Unit 1
PI IE01 - Unplanned Scrams per 7,000 Critical Hours,
IE03 - Unplanned Power Changes per 7,000 Critical Hours,
IE04 - Unplanned Scrams with Complications,
MS05 - Safety System Functional Failures (SSFF),
MS06 - MSPI Emergency AC Power System, MS07 - MSPI
High Pressure Injection System, MS08 - MSPI Heat
Removal System, MS09 - MSPI Residual Heat Removal
System, MS10 - MSPI Cooling Water System
01/2024 -
2/2024
71151
Miscellaneous
PI Summary
Report - Unit 2
PI IE01 - Unplanned Scrams per 7,000 Critical Hours,
IE03 - Unplanned Power Changes per 7,000 Critical Hours,
IE04 - Unplanned Scrams with Complications,
MS05 - Safety System Functional Failures (SSFF),
MS06 - MSPI Emergency AC Power System, MS07 - MSPI
High Pressure Injection System, MS08 - MSPI Heat
Removal System, MS09 - MSPI Residual Heat Removal
System, MS10 - MSPI Cooling Water System
01/2024 -
2/2024
501000075234
D5 FOST Vault Annual Inspection
07/13/2023
501000075530
D6 FOST Annual Inspection
07/26/2023
Corrective Action
Documents
501000076915
D6 Fuel Oil Storage System Leakage
09/23/2023
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
501000088191
Corrosion on Underground FO Piping
07/25/2024
D6 FOST Vault
Inspection Photos
07/26/2023
Operating
Experience
Evaluation
AR #501000059751; Westinghouse Tech Bulletin 22-1:
Reactor Coolant Pump (RCP) Casing Design Analysis
2/09/2022
501000027864
On Demand Oil Change for 21 SI Pump Sump
05/28/2019
501000040594
Paint Chips found in 21 SI Pump Sump
05/14/2020
501000056868
SI Pump Cracked OB Radial Bearing
10/08/2021
501000057150
O-Ring size discrepancy
10/12/2021
501000078497
SI Pump Drain Line Loose
11/01/2023
Corrective Action
Documents
501000078825
11/10/2023
Engineering
Evaluations
2000031268
Flux Rate Trip During SP 2047
10/29/2024