IR 05000387/2025040

Supplemental Inspection Report 05000387/2025040 and 05000388/2025040 and Follow-Up Assessment Letter

ML25163A059
Person / Time
Site:	Susquehanna
Issue date:	06/12/2025
From:	Sarah Elkhiamy Division of Operating Reactors
To:	Berryman B Susquehanna
References
EPID I-2025-040-0006 IR 2025040
Download: ML25163A059 (1)

Text

June 12, 2025

SUBJECT:

SUSQUEHANNA STEAM ELECTRIC STATION, UNITS 1 AND 2-95001 SUPPLEMENTAL INSPECTION REPORT 05000387/2025040 AND 05000388/2025040 AND FOLLOW-UP ASSESSMENT LETTER

Dear Brad Berryman:

On May 15, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed a supplemental inspection using Inspection Procedure 95001, Supplemental Inspection Response to Action Matrix Column 2 (Regulatory Response) Inputs, and the NRC inspection team discussed the results of this inspection and the implementation of your corrective actions with Edward Casulli, Site Vice President, and other members of your staff.

The NRC performed this inspection to review your stations actions in response to a White finding in the Mitigating Systems cornerstone which was documented and finalized in NRC Inspection Report 05000387/2025090 and 05000388/2025090 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML25016A306). On April 11, 2025, you informed the NRC that your station was ready for the supplemental inspection.

The NRC determined that your staffs evaluation identified the cause of the White finding.

Specifically, the root cause analysis for the White finding identified two root causes. The first root cause determined that station leadership did not ensure that electricians and engineers involved in the emergency diesel generator (EDG) high voltage cabinet inspection preventative maintenance activities had the correct standards for recognizing and documenting in condition reports the condition of the degraded linear reactors. The second root cause identified that the scoping phase of the work management process, NDAP-00-1912, Scheduling and Coordination of Work, for EDG system outage windows did not always ensure that the required scope is selected. Additionally, the work management process did not ensure adequate stakeholder review took place prior to removing work from the schedule. Corrective actions to preclude repetition are discussed in detail in the enclosed inspection report.

Overall, the NRC determined that your problem identification, causal analyses, and corrective actions sufficiently addressed the performance issues that led to the White finding.

All inspection objectives, as described in Inspection Procedure 95001, were met, and this inspection is, therefore, closed. With the closure of this White finding, and as a result of our continuous review of plant performance, the NRC has updated its assessment of Susquehanna Steam Electric Station, Units 1 and 2. This assessment supplements, but does not supersede, the end-of-cycle letter issued on March 11, 2025. Based on successful completion of the supplemental inspection and issuance of this inspection report, Susquehanna Steam Electric Station, Units 1 and 2, have transitioned to the licensee response column of the NRC Action Matrix (Column 1) as of the date of the exit and regulatory performance meeting for this inspection on May 15, 2025.

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, Sarah H. Elkhiamy, Chief Operations Branch Division of Operating Reactor Safety

Docket Nos. 05000387 and 05000388 License Nos. NPF-14 and NPF-22

Enclosure:

As stated

Inspection Report

Docket Number:

05000387 and 05000388

License Number:

NPF-14 and NPF-22

Report Number:

05000387/2025040 and 05000388/2025040

Licensee:

Susquehanna Nuclear, LLC

Facility:

Susquehanna Steam Electric Station, Units 1 and 2

Location:

769 Salem Blvd., Berwick, PA

Inspection Dates:

May 12, 2025 to May 15, 2025

Inspectors:

B. Dyke, Operations Engineer

M. Patel, Senior Operations Engineer

A. Golio, Reactor Inspector (observer)

Approved By:

Sarah H. Elkhiamy, Chief

Operations Branch

Division of Operating Reactor Safety

SUMMARY

The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a 95001 supplemental inspection at Susquehanna Steam Electric Station, Units 1 and 2, 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

Type Issue Number Title Report Section Status NOV 05000377, 05000378/2025090 Failure to Identify and Correct B Emergency Diesel Generator Linear Reactor Degradation 95001 Closed

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 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

- TEMPORARY INSTRUCTIONS, INFREQUENT AND ABNORMAL

95001 - Supplemental Inspection Response to Action Matrix Column 2 (Regulatory Response)

Inputs

The inspectors reviewed and selectively challenged aspects of Susquehannas problem identification, causal analysis, and corrective actions to ensure the causes of the White performance issue were correctly identified and corrective actions were adequate to promptly and effectively address and preclude repetition. The White finding and related Notice of Violation of Title 10 of the Code of Federal Regulations Part 50, Appendix B, Criterion XVI, Corrective Action, and Susquehanna Steam Electric Station, Units 1 and 2, Technical Specification (TS) 3.8.1, AC Sources-Operating, was associated with the failure to establish measures to assure a condition adverse to quality related to degradation of the B emergency diesel generator (EDG) linear reactors (LRs) was promptly identified and corrected. As a result, the B EDG tripped on generator differential current and was rendered inoperable when the C phase LR failed during a surveillance test on April 8, 2024. Consequently, the B EDG was rendered inoperable prior to April 8, 2024, for a period longer than its TS allowed outage time, and the unit was not shut down and placed in Mode 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and Mode 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The preliminary White finding and apparent violation was documented in NRC Inspection Report 05000387/2024012 and 05000388/2024012 (Agencywide Documents Access and Management System (ADAMS) Accession Number ML24330A017). The final significance determination of the White finding and Notice of Violation was documented in NRC Inspection Report 05000387/2025090 and 05000388/2025090 (ML25016A306).

Susquehanna performed and documented a root cause analysis (RCA) in Issue Report 04735065. The NRC inspectors' review of the Susquehanna White performance issue and the associated assessment are documented below.

Objective 1: Ensure that the root and contributing causes of the White performance issue are understood

Under this objective, the inspectors reviewed the RCA the licensee conducted for the failure to establish measures to assure a condition adverse to quality related to degradation of the B EDG LRs were promptly identified and corrected as documented in NRC Inspection Report 05000387/2024012 and 05000388/2024012 (ML24330A017). The inspectors' review consisted of an evaluation of the following:

• the licensee's identification of the issue(s)

• when and how long the issue(s) existed

• prior opportunities for identification

• documentation of significant plant-specific consequences and compliance concerns

• use of systematic methodology to identify causes with a sufficient level of supporting detail

• consideration of prior occurrences

• identification of extent of condition and extent of cause

NRC Assessment: The team concluded that this objective was met.

The inspectors determined the licensee had prior opportunities to identify and address the conditions that led to the White finding, prior to the recent licensee identification. The RCA adequately assessed and addressed prior opportunities to identify the issues. The licensee appropriately understood the risk and compliance aspects of the White finding. The RCA identified two root causes and two contributing causes:

• Root Cause (RC1): Station leadership did not ensure that electricians and engineers involved in the EDG high voltage (HV) cabinet inspection preventative maintenance (PM) activities had the correct standards for recognizing and documenting in condition reports (CRs) the condition of the degraded LRs. As a result, station leadership was not aware of the actual condition of the LRs until April 2024 when the C phase LR in the B EDG failed.

• Root Cause (RC2): The scoping phase of the current work management process, NDAP-00-1912, for EDG system outage windows (SOWs) did not always ensure that the required scope is selected. Additionally, the work management process did not ensure adequate stakeholder review took place prior to removing work from the schedule. As a result, the LRs were not replaced in the August 2022 B EDG SOW.

• Contributing Cause 1 (CC1): The issues with the LRs were not documented in CRs or communicated to department leadership because Engineering and Electrical Maintenance personnel did not fully understand that the darkened appearance, epoxy peeling, and debris falling from the LRs were potentially consequential signs of component aging that warranted a CR being written.

• Contributing Cause 2 (CC2): The life cycle management plan for the EDG excitation system was not developed in a timely manner after the relevant Electric Power Research Institute guidance was issued. The Electric Power Research Institute guidance issued in December 2013 for the EDG excitation system was not incorporated into the Life Cycle Management Process procedure (NSEP-AD-0005)until September 2021. When the procedure was changed, no plan was developed nor were actions created to track generation of the plan resulting in no formal plan to address end of life of the original plant equipment.

a. Identification: The issues resulting in the White finding were identified by the licensee.

The licensees RCA noted that the event became self-revealing on April 8, 2024, during the performance of SO-024-001B, Monthly Diesel Generator B Operability Test, when the B EDG experienced a failure of its C phase LR resulting in a trip on generator differential. As a result, Unit 2 entered TS 3.8.1, Limiting Condition for Operation (LCO)

Condition B, for one EDG inoperable.

b. Exposure Time: The licensee's RCA documented that the issue existed for 96 days which covers the period from January 3, 2024 (conclusion of the last B EDG 24-hour satisfactory test run) through April 8, 2024 (failure date of the B EDG LR).

c. Identification Opportunities: The licensee's RCA documented that there were multiple opportunities to identify the conditions leading to the White finding. The change analysis focusing on PM inspections of the EDG HV cabinets uncovered multiple instances where signs of overheating were documented by maintenance personnel but not entered into the corrective action program. The barrier analysis also noted instances where industry guidance and operating experience (OE) could have been incorporated into station procedures and programs.

d. Risk and Compliance: The licensee's RCA documented the plant-specific consequences and compliance concerns. Specifically, it identified that the TS Surveillance Requirement 3.8.1.3 was not met, and the station entered Unit 2 TS 3.8.1, LCO Condition B for the inoperable EDG. Additionally, based on the apparent cause of the failure, there is evidence that the condition existed for longer than allowed by TS 3.8.1 LCO. The licensee's RCA also documented the qualitative consequences of the event, including the 96-day exposure time, and the White finding and Notice of Violation for Susquehannas failure to promptly identify and correct a condition adverse to quality associated with the B EDG.

e. Methodology: The licensee's RCA evaluated performance issues using a systematic evidence-based approach to identify root and contributing causes. Specifically, the licensee's RCA utilized a diverse set of techniques in conducting the investigation including event and casual factor chart, change analysis, why analysis, barrier analysis, equipment failure checklist, failure modes analysis, organization and programmatic checklist, safety culture review, interview questions, and training needs analyses.

The inspectors reviewed each of the documented method results and determined that the different methods provided a detailed, reliable, and scrutable evaluation. Also, the inspectors determined these analyses were performed with sufficient rigor and depth to identify the root and contributing causes.

f. Level of Detail: The inspectors determined that the licensee's RCA was conducted to a level of detail commensurate with the significance and complexity of the White performance issue. Specifically, the licensee's RCA utilized a formal cause evaluation process to identify problems and determine corrective actions. The RCA was performed by a cross-disciplinary team of individuals with various backgrounds and levels of experience. Additionally, the RCA was reviewed by external experts, as recommended by station procedure.

g. Operating Experience: The inspectors determined that the licensee's RCA considered prior occurrences of the performance issue and knowledge of prior OE. Specifically, the RCA reviewed both internal site-specific OE and external industry OE using the Institute of Nuclear Power Operations Industry Reporting and Information System reporting database and trends database for NRC violations. The inspectors noted that, as a result of this review, the licensee identified instances that supported the development of CC2.

h. Extent of Condition and

Cause:

See discussion in Objective 2.

Objective 2: Ensure that the extent of condition and extent of cause of White performance issues are identified

Under this objective, the inspectors assessed the licensee's RCA, associated corrective actions, procedures, and work orders (WO) to evaluate the licensee's extent of condition and extent of cause.

NRC Assessment: The team concluded that this objective was met.

Extent of Condition and

Cause:

The inspectors determined that the licensee's RCA identified the extent of condition and the extent of cause of the performance issue. Specifically, the RCA determined that the extent of condition was applicable to the A to D EDGs as these EDGs each have the same LR design with approximately the same operating life. The E EDG was also evaluated under the extent of condition; however, this EDG has a different design LR which was previously replaced with new LRs in 2023. Other EDGs were reviewed at the site and determined to not have similar LRs. Actions have been generated to replace all the A to D original LRs. The B, C, and D LRs have been replaced with the new original design or refurbished LRs to date, mitigating risk until delivery of the new, upgraded design from the vendor. The A EDG LRs were replaced with the first set of new, upgraded design LRs in February 2025. The station has established a replacement strategy to implement the upgraded design in all the EDGs over the next 2 years. This strategy was developed to allow run time and data collection on the new upgraded parts. For the extent of cause, the inspectors noted that the licensee developed corrective actions to assess the potential for instances of RC1, RC2, CC1, and CC2 to exist within other plant processes, programs, equipment, or human performance.

The inspectors reviewed the safety culture components referenced in NUREG-2165, Safety Culture Common Language, to determine if these were appropriately considered during the licensees evaluations of the root causes, extent of conditions, and extent of causes. The licensee conducted a review of the Safety Culture Attributes from NUREG2165 and identified 12 attributes that were applicable.

Objective 3: Ensure that completed corrective actions to address and preclude repetition of White performance issues are timely and effective

Under this objective, the inspectors assessed the appropriateness and timeliness of the licensee's corrective actions.

NRC Assessment: The team concluded that this objective was met. The inspectors noted that there was one completed corrective action to preclude repetition (CAPR) for each root cause of the white performance issue.

a. Completed CAPRs

1) CAPR (ACT-07-CR-2024-16012): Revise the EDG HV cabinet inspection PMs (E1940-01, E1940-02, E1940-03, E1940-04, and E1940-05) to provide a picture of a new LR and instructions to ensure electricians generate CRs whenever change in appearance is detected (RC1).

2) CAPR (ACT-53-CR-2024-16012): Revise NDAP-00-1912 to require schedulers to schedule all corrective WOs for EDG SOWs in the scope phase, to cross-functionally review and validate them during the scope selection freeze, and to require the use of a scope change form for removing any EDG SOW WOs after the scope selection freeze (RC2).

The inspectors reviewed the applicable WOs, procedure revisions, and PM strategy documentation to ensure the CAPRs were implemented timely and were effective.

b. Other Completed Corrective Actions

The licensee identified the following corrective actions to address RC1:

1) Conduct a rostered briefing/case study for station managers and supervisors that includes lessons learned from this root cause to reinforce station standards for generating CRs at a low threshold (ACT-08-CR-2024-16012).

The inspectors reviewed the briefing material and attendance rosters to confirm the training was completed in the first quarter of 2025.

2) Managers/superintendents conduct rostered meetings with personnel in their group to reinforce the need for clear and open communications and documentation in CRs of potential issues at the lowest level. Groups included personnel from Maintenance, Engineering, Operations, Radiation Protection, Chemistry, Security, Training, Projects, Nuclear Oversight, Nuclear Regulatory Affairs, Emergency Preparedness, Work Management Online, and Work Management Outage (ACT-16 through ACT-25-CR-2024-16012, and ACT-70 through ACT-72-CR-2024-16012).

The inspectors reviewed the briefing material and attendance rosters to confirm the training was completed in the first quarter of 2025.

3) Revise NDAP-00-0007, Susquehanna Steam Electric Station Governance, Oversight, Support, and Perform Model, and NDAP-00-0036, Station Observation Program, to clearly state the roles of managers and supervisors in oversight of the corrective action program and to provide additional instruction in documenting equipment issues as part of field observations (ACT-49-CR-2024-16012, ACT-50-CR-2024-16012).

The inspectors reviewed the applicable procedures to confirm this corrective action was completed in March 2025.

The licensee identified the following corrective actions to address RC2:

1) Conduct rostered briefings with Work Management Online personnel involved in the scheduling of online work to ensure they understand the requirements of the changes to NDAP-00-1912 and how those changes will be implemented (ACT-55-CR-2024-16012).

The inspectors reviewed the rostered briefing documentation to confirm this corrective action was completed in May 2025.

2) Revise NDAP-00-1912 to require schedulers to schedule all corrective WOs for high-pressure coolant injection (HPCI), reactor core isolation cooling (RCIC), core spray, and residual heat removal (RHR) SOWs during the scope phase, to cross-functionally review and validate them during the scope selection freeze, and to require the use of a scope change form for removing any HPCI, RCIC, core spray, and RHR WO after the scope selection freeze (ACT-54-CR-2024-16012).

The inspectors reviewed the applicable procedure to confirm this corrective action was completed in March 2025.

3) Perform a cross-functional review of the corrective WOs open greater than 2 years for the HPCI, RCIC, core spray, RHR, and EDG systems in the current station backlog to determine if any need to be rescheduled based on station risk and maintenance rule impacts. This cross-functional review will be performed by a quorum that includes Work Management, Operations, Engineering, and Maintenance (ACT-64-CR-2024-16012).

The inspectors reviewed closure documentation to confirm this corrective action was completed in March 2025.

The licensee identified the following corrective action to address CC1:

1) Based on the training needs analysis approved under DI-2025-01611, revise Engineering initial training lesson plan EG329, engineering traits, fundamentals, and to include lessons learned and photos from this root cause on recognizing signs of overheating in a linear reactor (ACT-59-CR-2024-16012).

The inspectors reviewed training documentation to confirm this corrective action was completed in April 2025.

The licensee identified the following additional corrective actions:

1) Replace LR for the B EDG with a new LR of the original design and replace the LRs for the C and D EDGs with refurbished LRs of the original design (WO2363340-0, WO2363338-0, and WO2773801-0, respectively).

The inspectors reviewed the WOs to confirm that the B EDG LR was replaced in April 2024 and the C and D EDG LRs were replaced by April 2025.

2) Document completion approval of Engineering Change EC2770598 for the Engine System, Inc. improved redesign of the LRs for the A, B, C, and D EDGs.

The inspectors reviewed the Engine System, Inc. documentation to confirm the improved specifications of the redesigned LRs.

3) Replace LRs for the A EDG with the new design of LRs as part of a 2-year plan to replace all LRs on-site with the upgraded design (WO2363336-0).

The inspectors reviewed the WO to confirm the A EDG was replaced with the new design in February 2025.

Objective 4: Ensure that pending corrective action plans direct prompt and effective actions to address and preclude repetition of White performance issues

Under this objective, the inspectors assessed the appropriateness and timeliness of the licensee's planned corrective actions.

NRC Assessment: The team concluded that this objective was met. There are no pending CAPRs.

a. Other Planned Corrective Actions

The licensee identified the following corrective actions to address RC1:

1) Engineering managers/Maintenance superintendents to perform at least one paired observation with each of the supervisors in their group to demonstrate they have the correct standards for reporting and documenting potential issues in CRs and that standards are reinforced (ACT-11 through ACT-15-CR-2024-16012)

The inspectors noted that the licensee's behavioral monitoring plan for all Engineering and Maintenance groups is planned to be completed by June 2025.

2) Maintenance superintendents for the Electrical, Mechanical, and Instrumentation and Control (I&C) maintenance groups will perform a minimum of five observations of the extent of cause inspections from the root cause evaluation. These observations will assess and document whether workers demonstrate the correct standards for reporting and documenting potential issues in CRs and that supervisors are reinforcing those standards (ACT-46 through ACT-48-CR-2024-16012).

The inspectors noted that these inspections are planned to be completed by October 2025.

3) Conduct recurring rostered briefings/case studies for station managers and supervisors that includes lessons learned from this root cause to reinforce station standards for generating CRs at a low threshold. Training to be performed once per year for 3 years (ACT-09 through ACT-10-CR-2024-16012).

The inspectors noted that the recurring training is scheduled to be performed yearly until 2027.

4) Interim and Final Effectiveness Reviews: Perform a check-in self-assessment (CISA)using a cross-discipline team of a minimum of 10 random visual inspection PM WOs performed by Electrical Maintenance, I&C, and Mechanical Maintenance. The CISA will determine if there is alignment between the WO documentation, CRs written to document issues, and supervisor/manager awareness of the issues. If discrepancies or a lack of alignment is found, the sample size will be expanded to an additional 10 visual inspection PM WOs or all PM WOs completed during the period (ACT-66 and ACT-67-CR-2024-16012).

The inspectors noted that an interim effectiveness review is planned for September 2025 and the final effectiveness review is planned for May 2026.

The licensee identified the following corrective actions to address RC2:

1) Interim and Final Effectiveness Reviews: Perform a CISA using a cross-discipline team to verify that the revised scoping process in NDAP-00-1912 has been effective.

The CISA will include a sampling size of two randomly selected HPCI, RCIC, core spray, RHR, or EDG SOWs from the previous 6 months that will be reviewed to determine if all corrective WOs that were initiated prior to scope selection were included in the initial SOW scope, if any corrective WOs removed prior to scope selection freeze had team alignment on their exclusion, and if any corrective WOs removed after scope selection freeze were documented using approved scope change forms (ACT-68 and ACT-69-CR-2024-16012).

The inspectors noted that an interim effectiveness review is planned for December 2025 and the final effectiveness review is planned for September 2026.

The licensee identified the following corrective actions to address CC1:

1) Based on the training needs analysis approved under DI-2025-01611, implement continuing training to Electrical Maintenance, I&C, Mechanical, and Engineering personnel on recognizing the signs of overheated electrical components using lessons learned and photos from this root cause, and emphasizing that CRs need to be written at a low threshold when potential issues are found (ACT-56-CR-2024-16012 and ACT-79 through ACT-81-CR-2024-16012).

The inspectors noted that a continuing training program is planned to be implemented by November 2025.

2) Based on the training needs analysis approved under DI-2025-01611, revise Lesson Plan EG342, Aging Management Program Walkdowns, to include the LRs failure event as OE for discussion (ACT-57-CR-2024-16012).

3) Based on the training needs analysis approved under DI-2025-01611, revise Maintenance Initial Training Lesson Plan AD015, Work Package Standards and Expectations, to include lessons learned and photos from this root cause, emphasizing that CRs need to be written at a low threshold when issues are found in the field (ACT-58-CR-2024-16012).

The inspectors noted that the revised lesson plans are planned to be completed by May 2025.

4) For Electrical, Mechanical, and I&C maintenance groups, perform inspections of the components/areas in the spreadsheet attached to the ACT to ensure that there are no degraded equipment or component conditions that have not been previously documented in CRs. If issues are found that were not previously documented, generate a CR (ACT-61 through ACT-63-CR-2024-16012).

The inspectors noted that the inspections are planned to be completed by May 2026.

The licensee identified the following corrective actions to address CC2:

1) Develop a life cycle management plan for the EDG excitation system IAW NSEP-AD-0005, Life Cycle Management Process (ACT-60-CR-2024-16012).

The inspectors noted the life cycle management plan is to be developed by June 2025.

2) Determine which systems/sub-systems/components listed in NSEP-AD-0005, Life Cycle Management Process, do not currently have plans. Create actions to develop plans for these systems/sub-systems/components (ACT-65-CR-2024-16012).

The inspectors noted the life cycle management review is planned to be completed by June 2025.

3) Perform a system vulnerability review per ER-2002 on the EDGs which includes a review of applicable Institute of Nuclear Power Operations, Electric Power Research Institute, and NRC information notices (ACT-90-CR-2024-16012).

The inspectors noted the vulnerability review is planned to be completed by July 2025.

The licensee identified the following additional corrective actions:

1) Replace LRs for the B, C, and D EDGs with the upgraded, new design LRs (WO2742113-0, WO2363338-6, and WO2363332-0).

The inspectors reviewed the WOs to confirm that the B, C, and D EDG LRs are planned to be replaced with the new design LRs by July 2026.

The inspectors reviewed the licensee's planned corrective actions and determined they were appropriate to address the root causes of the White performance issue and were prioritized commensurate with the significance.

Conclusion

Overall, the inspectors determined that the licensees problem identification, causal analyses, and corrective actions sufficiently addressed the performance issues that led to the White finding. The inspectors determined the corrective actions have been prioritized commensurate with the significance and regulatory compliance, corrective actions taken were prompt and effective, and the Notice of Violation related to the supplemental inspection is sufficiently addressed. All inspection objectives, as described in Inspection Procedure 95001, were met.

Scheduled corrective action items will be inspected as part of the ongoing NRC baseline inspection program. Therefore, this inspection is closed.

INSPECTION RESULTS

No findings were identified.

EXIT MEETINGS AND DEBRIEFS

The inspectors verified no proprietary information was retained or documented in this report.

• On May 15, 2025, the inspectors conducted an exit and regulatory performance meeting regarding the 95001 supplemental inspection results to Edward Casulli, Site Vice President, and other members of the licensee staff.

DOCUMENTS REVIEWED

Inspection

Procedure

Type

Designation

Description or Title

Revision or

Date

95001

Corrective Action

Documents

CR-2024-05881

'B' DG Tripped on High Differential Current During

SO-024-001B

04/08/2024

ACT-07-

CR-2024-16012

Enhancement for Scope of DG High Voltage Cabinet

Inspections

03/05/2025

ACT-53-

CR-2024-16012

Revision of NDAP-00-1912, Scheduling and Coordination of

Work

03/05/2025

CR-2024-16012

Root Cause Investigation Report, B Diesel Generator

C-Phase Linear Reactor Failure

04/24/2025

Miscellaneous

SSES B DG Linear Reactor Failure Inspection Matrix

Roadmap

Revision 0

SSES 'B' DG Linear Reactor Failure Action Roadmap

Revision 0

ESI-8004137-FA

Failure Analysis of Linear Reactor and Voltage Regulator for

Talen Energy

Revision 1

Procedures

LS-120

Issue Identification and Screening Process

Revision 16

LS-125

Corrective Action Program (CAP) Procedure

Revision 17

LS-125-1001

Root Cause Analysis Manual

Revision 12

LS-126

Self-Assessment and Benchmarking

Revision 8

NDAP-00-0706

Process for Issues Involving Significant Regulatory

Interaction

Revision 11