IR 05000277/2025010
| ML25353A412 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/22/2025 |
| From: | Nicole Warnek Division of Operating Reactors |
| To: | Mudrick C Constellation Energy Generation, Constellation Nuclear |
| References | |
| IR 2025010 | |
| Download: ML25353A412 (0) | |
Text
December 22, 2025
SUBJECT:
PEACH BOTTOM ATOMIC POWER STATION, UNITS 2 AND 3 - BIENNIAL PROBLEM IDENTIFICATION AND RESOLUTION INSPECTION REPORT 05000277/2025010 AND 05000278/2025010
Dear Christopher Mudrick:
On September 26, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed a problem identification and resolution inspection at your Peach Bottom Atomic Power Station, Units 2 and 3, and discussed the results of this inspection with Martin Bonifanti, Site Vice President, and other members of your staff. The results of this inspection are documented in the enclosed report.
Due to the temporary cessation of government operations, which commenced on October 1, 2025, the NRC began operating under its Office of Management and Budget-approved plan for operations during a lapse in appropriations. Consistent with that plan, the NRC operated at reduced staffing levels throughout the duration of the shutdown. However, the NRC continued to perform critical health and safety functions and make progress on other high-priority activities associated with the ADVANCE Act and Executive Order 14300. On November 13, 2025, following the passage of a continuing resolution, the NRC resumed normal operations. As a result, the issuance of this inspection report is delayed beyond the timeliness criteria specified in Inspection Manual Chapter 0611, Power Reactor Inspection Reports.
The NRC inspection team reviewed the stations problem identification and resolution program to confirm that the station was complying with NRC regulations and licensee standards. Based on the samples reviewed, the team determined that your program complies with NRC regulations and applicable industry standards such that the Reactor Oversight process can continue to be implemented.
The team also evaluated the stations effectiveness in identifying, prioritizing, evaluating, and correcting problems, reviewed licensee audits and self-assessments, and its use of industry and NRC operating experience information. The results of these evaluations are in the enclosure. Finally, the team reviewed the stations programs to establish and maintain a safety-conscious work environment and interviewed station personnel to evaluate the effectiveness of these programs. Based on the teams observations and the results of these interviews, the team found no evidence of challenges to your organizations safety-conscious work environment. Your employees appeared willing to raise nuclear safety concerns through at least one of the several means available.
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.
If you contest the violation or the significance or severity of the violation 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 I; the Director, Office of Enforcement; and the NRC Resident Inspector at Peach Bottom Atomic Power Station, Units 2 and 3.
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, Jason E. Schussler, Team Leader Technical Support and Administrative Team Division of Operating Reactor Safety
Docket Nos. 05000277 and 05000278 License Nos. DPR-44 and DPR-56
Enclosure:
As stated
Inspection Report
Docket Numbers:
05000277 and 05000278
License Numbers:
Report Numbers:
05000277/2025010 and 05000278/2025010
Enterprise Identifier: I-2025-010-0005
Licensee:
Constellation Energy Generation, LLC
Facility:
Peach Bottom Atomic Power Station, Units 2 and 3
Location:
Delta, PA
Inspection Dates:
September 8, 2025 to September 26, 2025
Inspectors:
H. Anagnostopoulos, Senior Health Physicist
C. Dukehart, Resident Inspector
T. Eck, Senior Physical Security Inspector
M. Hardgrove, Senior Project Engineer
N. Mentzer, Senior Project Engineer
Approved By:
Jason E. Schussler, Team Leader
Technical Support and Administrative Team
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a biennial problem identification and resolution inspection at Peach Bottom Atomic Power Station, Units 2 and 3, 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
Failure to perform sufficient testing to justify deferring maintenance on high-pressure service water pump motor Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000277,05000278/2025010-01 Open/Closed None (NPP)71152B A self-revealed Green finding and associated non-cited violation (NCV) of Peach Bottom Atomic Power Station Technical Specification 5.4.1, Procedures, was identified when the licensee failed to maintain and implement maintenance procedures for the high-pressure service water (HPSW) pump motors. Specifically, Constellation staff did not perform baker motor testing on the HPSW pump motors prior to deferring motor winding replacement beyond the recommended frequency. This resulted in the 2D HPSW pump motor failing during surveillance testing due to age-related degradation of motor winding insulation.
Additional Tracking Items
None.
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 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.
OTHER ACTIVITIES - BASELINE
71152B - Problem Identification and Resolution Biennial Team Inspection (IP Section 03.04)
- (1) The inspectors performed a biennial assessment of the effectiveness of the licensees problem identification and resolution program, use of operating experience, self-assessments and audits, and safety conscious work environment.
- Problem Identification and Resolution Effectiveness: The inspectors assessed the effectiveness of the licensees problem identification and resolution program in identifying, prioritizing, evaluating, and correcting problems. The inspectors also conducted a five-year review of Unit 2 and Unit 3 DC power sources. The corrective actions for the following NCVs and findings were evaluated as part of the assessment: NCV 05000277,05000278/2023010-01; NCV 05000277,05000278/2023402-01; NCV 05000277,05000278/2023004-01; NCV 05000277,05000278/2023004-02; NCV 05000277, 050002782/2023004-03; NCV 05000277,05000278/2024402-01; NCV 05000277,05000278/2024002-01; NCV 05000277,05000278/2024002-02; NCV 05000277,05000278/2024002-03; NCV 05000277,05000278/2024002-04; NCV 05000277,05000278/2024002-05; and NCV 05000277,05000278/2024401-01.
- Operating Experience: The inspectors assessed the effectiveness of the licensees processes for use of operating experience,
- Self-Assessments and Audits: The inspectors assessed the effectiveness of the licensees identification and correction of problems identified through audits and self-assessments.
- Safety Conscious Work Environment: The inspectors assessed the effectiveness of the stations programs to establish and maintain a safety-conscious work environment.
INSPECTION RESULTS
Assessment 71152B Problem Identification and Resolution Program Effectiveness:
The inspectors determined that the licensee's problem identification and resolution program for Peach Bottom was generally effective and adequately supported nuclear safety and security.
Identification: The team reviewed a sample of issues that have been processed through Peach Bottom's problem identification and resolution program since the last biennial team inspection, including NCVs of regulatory requirements and other documented findings. The team determined that, in general, the station identified issues and entered them into the corrective action program at a low threshold and timely manner.
Prioritization and Evaluation: Based on the samples reviewed, the team determined that Peach Bottom was effective at prioritizing and evaluating issues commensurate with the safety significance of the identified problem. Inspectors observed that at the station corrective action program meetings, issues were generally screened and prioritized at the appropriate level and that corrective actions were assigned to address the issues.
Corrective Action: The team reviewed a sample of corrective actions and concluded that Peach Bottom was generally effective in developing corrective actions that were appropriately focused to correct the identified problems.
Assessment 71152B Operating Experience:
The inspectors reviewed a sample of operating experience captured in the corrective action program and sampled operating experience from NRC, industry, vendors, and third-party groups. Overall, for the samples selected, Peach Bottom was generally performing the appropriate assessments for station applicability.
Assessment 71152B Self-Assessments and Audits:
The inspectors determined that Peach Bottom was adequately performing self-assessments and audits in accordance with licensee procedures and implementing corrective actions as needed.
Assessment 71152B Safety-Conscious Work Environment:
The team interviewed a total of 33 individuals in one-on-one interviews. The purpose of these interviews was
- (1) to evaluate the willingness of the licensee staff to raise nuclear safety issues,
- (2) to evaluate the perceived effectiveness of the corrective action program at resolving identified problems, and
- (3) to evaluate the licensee's safety conscious work environment. The personnel interviewed were randomly selected by the inspectors from Engineering, Maintenance, Operations, Radiation Protection, Chemistry, Emergency Preparedness, and Security. To supplement these discussions, the team interviewed the Employee Concern Program (ECP) Coordinator to assess their perception of the site employees' willingness to raise nuclear safety concerns and also reviewed the ECP case log and select case files.
All individuals interviewed indicated that they would raise safety concerns. Individuals felt that their management was receptive to receiving safety concerns and generally addressed them promptly, commensurate with the significance of the concern. Interviewees indicated that they were adequately trained and proficient on initiating condition reports. Most interviewees were aware of the licensee's ECP, and all stated they would use the program if necessary and expressed confidence that their confidentiality would be maintained if they brought issues to the ECP. When asked whether there have been any instances where individuals experienced retaliation or other negative reaction for raising safety concerns, all individuals interviewed stated that they had neither experienced nor heard of an instance of retaliation at the site.
The team determined that the processes in place to mitigate potential safety culture issues were adequately implemented.
Failure to perform sufficient testing to justify deferring maintenance on high pressure service water pump motor Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems
Green NCV 05000277,05000278/2025010-01 Open/Closed
None (NPP)71152B A self-revealed Green finding and associated NCV of Peach Bottom Atomic Power Station Technical Specification 5.4.1, Procedures, was identified when the licensee failed to maintain and implement maintenance procedures for the HPSW pump motors. Specifically, Constellation staff did not perform baker motor testing on the HPSW pump motors prior to deferring motor winding replacement beyond the recommended frequency. This resulted in the 2D HPSW pump motor failing during surveillance testing due to age-related degradation of motor winding insulation.
Description:
On October 1, 2024, the 2D HPSW pump failed to operate when demanded for surveillance testing in accordance with ST-O-032-301-2, HPSW pump, valve and flow functional and inservice test. Constellation generated issue report (IR) 04806129 in the corrective action program, performed initial troubleshooting, and replaced the pump. The initial troubleshooting was inconclusive. Constellation sent the pump and motor to the respective vendors for disassembly and failure analysis.
On December 12, 2024, Constellation completed the corrective action program evaluation (CAPE) IR 04806129-17 and concluded the apparent cause of the motor failure was age-related degradation of the motor stator insulation. The inspectors reviewed the CAPE and noted the pump vendor found no issues with the pump that would have caused the failure to start or prevent operation. However, the motor vendor found the motor winding grounded and upon disassembly confirmed the winding failure in the center of the motor core.
The inspectors found the long-term HPSW pump motor plan was implemented via preventative maintenance change (PMC-17-000913) in 2017 in alignment with the fleet performance centered maintenance (PCM) template for high and medium voltage electric motors revision 5. Subsequently, on March 12, 2018, the PCM template revision 6 was released and accepted at Peach Bottom which updated the basis for stator rewind periodicity.
Specifically, the PCM template specified the use of stator winding offline testing in accordance with MA-AA-723-330, Electrical testing of AC motors using baker instrument advanced winding analyzer, to support extending the stator rewind periodicity beyond 40 years for equipment that has limited run time due to being in standby mode.
In the CAPE, Constellation staff noted the 2D HPSW pump motor rewind maintenance was deferred beyond 40 years using electrical testing that was less robust than the testing in accordance with MA-AA-723-330. The inspectors reviewed ER-AA-200-1004, PCM Templates, and found the responsibility of the site subject matter expert and strategic engineer includes evaluating PCM template changes and initiating changes to the preventative maintenance strategies. However, the inspectors found no evidence of changes to the HPSW pump motor maintenance strategy following the revision 6 update to the fleet PCM template.
Corrective Actions: Constellation replaced the 2D HPSW pump motor and implemented the required electrical testing into the HPSW pump motor maintenance strategy.
Corrective Action References: 04806129
Performance Assessment:
Performance Deficiency: The inspectors determined that the licensee failed to implement electrical testing, described in the fleet PCM template for high and medium voltage electric motors, to the HPSW pump motor maintenance strategy while deferring motor winding replacement beyond the recommended frequency was a performance deficiency. Specifically, Constellation did not perform baker motor testing in accordance with MA-AA-723-330, Electrical testing of AC motors using baker instrument advanced winding analyzer, to assess the health of the motor winding insulation.
Screening: The inspectors determined the performance deficiency was more than minor because it was associated with the Equipment Performance 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, the 2D HPSW pump was declared inoperable when the motor failed during surveillance testing due to age-related degradation of motor winding insulation.
Significance: The inspectors assessed the significance of the finding using IMC 0609, Appendix A, The Significance Determination Process (SDP) for Findings At-Power. The inspectors determined the finding was of very low safety significance (Green) because all questions in IMC 0609, Appendix A, Exhibit 2, Section A were answered no.
Cross-Cutting Aspect: Not Present Performance. No cross-cutting aspect was assigned to this finding because the inspectors determined the finding did not reflect present licensee performance.
Enforcement:
Violation: Peach Bottom Technical Specification 5.4.1, Procedures, requires in part that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Appendix A of Regulatory Guide 1.33, Revision 0, November 1972. Regulatory Guide 1.33, Appendix A, section I.2 states "Preventive maintenance schedules should be developed to specify lubrication schedules, inspections of equipment, replacement of such items as filters and strainers, and inspection or replacement of parts that have a specific lifetime (such as wear rings)."
Contrary to the above, from March 12, 2018, until October 2, 2024, Constellation failed to maintain and implement maintenance procedures for the Unit 2 HPSW pump 2D motor windings before failure during surveillance testing.
Enforcement Action: This violation is being treated as an NCV, consistent with Section 2.3.2 of the Enforcement Policy.
EXIT MEETINGS AND DEBRIEFS
The inspectors verified that no proprietary information was retained or documented in this report.
- On September 26, 2025, the inspectors presented the biennial problem identification and resolution inspection results to Martin Bonifanti, Site Vice President, and other members of the licensee staff.
DOCUMENTS REVIEWED
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Corrective Action
Documents
04536484-10
04520495-04
04451174-03
04390304-02
04162789-02
04332338-02
04379955-03
04491087-02
04560167-09
04531583-07
04529400-04
04451174-03
04144798
04195630
04359830
04701497
04733050
04755847
04755850
04764223
04773592
04791132
04798580
04800158
04812412
04777937
04711908
04868000
04866612
04811509
04793000
04772166
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
04757350
04731670
04709888
04884251
04880332
04849557
04813390
04813932
04816029
04818231
04822986
04832634
04838590
04853760
04856687
04856687
04859450
04859876
04867730
04731272
04819165
04778968
04756747
04738568
04723382
04712784
04713348
04723454
04878278
04867486
04846575
04841523
04838366
04828929
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
04823103
04819910
04814366
04813000
04812264
04811879
04811295
04802598
04782173
04778754
04771208
04749694
04727747
04722409
04882947
04880622
04867901
04844358
04822673
04808117
04782564
04746811
04711097
04887705
04836552
04884166
04852007
04837011
04834999
04816843
04784742
04777941
04775461
04704043
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
04701490
04870898
04835193
4880523
04867785
04814136
04802598
04765671
04712229
04712233
04701196
04858042
04828163
04784496
04767380
04750797
04839254
04820917
Engineering
Evaluations
04797900-08
04749777-07
04812298-08
04738912-08
04813932-16
04806129-17
04806129
04851146
04712229
04819165-11-00
04731278-08-00
04794228-02-00
04785973
04738575
Procedures
Safety Conscious Work Environment
Employee Concerns Program Process
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
EP Performance Indicator Guidance
Maintenance Rule Functions Safety Significance
Classification
Issue Identification and Screening Process
Corrective Action Program (CAP) Procedure
Self-Assessments
7