IR 05000458/2025013
| ML25337A015 | |
| Person / Time | |
|---|---|
| Site: | River Bend  |
| Issue date: | 12/03/2025 |
| From: | Greg Warnick NRC/RGN-IV/DORS/EB1 |
| To: | Hansett P Entergy Operations |
| References | |
| IR 2025013 | |
| Download: ML25337A015 (0) | |
Text
December 03, 2025
SUBJECT:
RIVER BEND STATION - AGE-RELATED DEGRADATION INSPECTION REPORT 05000458/2025013
Dear Phil Hansett:
On September 25, 2025, the U.S. Nuclear Regulatory Commission (NRC) completed an inspection at River Bend Station and 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.
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.
However, due to the 43-day lapse in normal operations, the Office of Nuclear Reactor Regulation granted the Regional Offices an extension on the issuance of inspection reports that could not be issued within 45 days after the end of the inspection because of the shutdown.
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 IV; the Director, Office of Enforcement; and the NRC Resident Inspector at River Bend Station. 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 IV; and the NRC Resident Inspector at River Bend Station.
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, Gregory G. Warnick, Branch Chief Engineering Branch 2 Division of Operating Reactor Safety Docket No. 05000458 License No. NPF-47
Enclosure:
As stated
Inspection Report
Docket Number:
05000458
License Number:
Report Number:
Enterprise Identifier:
I-2025-013-0000
Licensee:
Entergy Operations, Inc
Facility:
River Bend Station
Location:
St. Francisville, LA
Inspection Dates:
September 08, 2025 to September 25, 2025
Inspectors:
W. Cullum, Senior Reactor Inspector
D. Stagner, Reactor Inspector
F. Thomas, Senior Reactor Inspector
Approved By:
Gregory G. Warnick, Branch Chief
Engineering Branch 2
Division of Operating Reactor Safety
SUMMARY
The U.S. Nuclear Regulatory Commission (NRC) continued monitoring the licensees performance by conducting a design basis assurance inspection (programs) inspection at River Bend Station, 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 Establish Performance Goals Under 10CFR50.65(a)(1) for the Standby Service Water System Following Repetitive Maintenance Rule Functional Failures Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2025013-01 Open/Closed
[P.2] -
Evaluation 71111.21N.
The inspectors identified a Green finding and associated non-cited violation (NCV) of 10CFR50.65(a)(1) when the licensee failed to identify a maintenance rule functional failure of the standby service water system. During a leak rate test of SWP-MOV57A, leakage was observed past the valve seat in excess of the standby service water system overall leakage acceptance criteria. This condition was incorrectly determined to not be a maintenance rule functional failure due to compensatory actions that were established to maintain operability of the standby service water system. As a result, the licensee did not monitor the performance or condition of structures, systems, or components (SSCs), against licensee-established goals in a manner sufficient to provide reasonable assurance that they are capable of fulfilling their intended functions in accordance with 10CFR50.65(a)(1).
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.
REACTOR SAFETY
71111.21N.04 - Age-Related Degradation Age-Related Degradation
- (1) E51-HYVC002, Reactor Core Isolation Cooling (RCIC) Governor Valve
- (2) SWP-P2B, Standby Service Water Pump B
- (3) SWP-MOV57A, Standby Service Water Normal Supply Header A Inlet Isolation Valve
- (4) Standby Service Water Cooling Tower Division 2 Spargers
- (5) C41-VEXF004A, Standby Liquid Control Pump 1A Discharge Header Explosive Valve
- (6) E22-S004, 4KV Metal Clad Breaker Control, 1E22*PNLS001 Bus 10 & 11
- (7) HVR-UC6, Auxiliary Building Unit Cooler 6 Fan Motor
- (8) ENS-SWG1A ACB1, 4160V Standby Switchgear Bus 1A - Circuit Breaker
INSPECTION RESULTS
Failure to Establish Performance Goals Under 10CFR50.65(a)(1) for the Standby Service Water System Following Repetitive Maintenance Rule Functional Failures Cornerstone Significance Cross-Cutting Aspect Report Section Mitigating Systems Green NCV 05000458/2025013-01 Open/Closed
[P.2] -
Evaluation 71111.21N.0 The inspectors identified a Green finding and associated non-cited violation (NCV) of 10CFR50.65(a)(1) when the licensee failed to identify a maintenance rule functional failure of the standby service water system. During a leak rate test of SWP-MOV57A, leakage was observed past the valve seat in excess of the standby service water system overall leakage acceptance criteria. This condition was incorrectly determined to not be a maintenance rule functional failure due to compensatory actions that were established to maintain operability of the standby service water system. As a result, the licensee did not monitor the performance or condition of structures, systems, or components (SSCs), against licensee-established goals in a manner sufficient to provide reasonable assurance that they are capable of fulfilling their intended functions in accordance with 10CFR50.65(a)(1).
Description:
Inspectors reviewed recent condition reports related to SWP-MOV57A. This valve is a component in the standby service water system (SSW). According to Updated Final Safety Analysis Report (UFSAR) Revision 27 Section 9.2.7.1, the standby service water system provides all the necessary cooling water to the reactor plant components required to safely bring the reactor to a cold shutdown condition and to maintain it in cold shutdown for a 30-day post-accident period. The system consists of two redundant trains with separate cooling tower basins which are capable of being cross connected but normally isolated by two motor-operated valves. SWP-MOV57A, along with three other valves in the system, has a design function to close during a design basis accident which serves to isolate the non-safety related loads from the safety-related loads in the standby service water system. Therefore, any leakage past this valve represents leakage outside of the standby service water system and must be accounted for to ensure adequate water inventory remains available for the 30-day mission time of the system following a design basis accident.
River Bend Station (RBS) uses calculations G13.18.13.2*086 Revision 4, Effects of Maximum Safeguards Operation on the Ultimate Heat Sink, and PM-194 Revision 12, Standby Cooling Tower Performance and Evaporation Losses Without Drywell Cooling Towers, to determine ultimate heat sink performance and inventory margin. These calculations determine that the current allowed system leakage is 6.9 gpm to ensure that enough inventory remains for the 30-day mission time.
In the maintenance rule program, there is a train level condition monitoring criterion established for the standby service water system. The train level condition monitoring criterion is described as, "Inability or failure of one SSW train to provide sufficient cooling water for heat removal capability from systems and components required to mitigate emergency conditions." The performance criterion is less than or equal to 2 per 2-year period.
The preventative maintenance template shows that the leakage test for SWP-MOV57A is conducted every refueling outage or once every 2 years. Therefore, the inspectors noted that the condition monitoring criteria would never be exceeded for SSW with the established performance criteria.
Looking at the history of maintenance rule functional failures, inspectors observed that in refueling outage RF-22, on March 24, 2023, SWP-MOV57A failed its leakage test with leakage documented at 30 gpm. This condition was documented in CR-RBS-2023-02997.
The licensee determined that this represented a maintenance rule functional failure since it represents system leakage above the acceptable level of 6.9 gpm. Therefore, SSW would not have enough inventory to satisfy its 30-day mission time.
Inspectors reviewed CR-RBS-2025-00779 which documents that, on February 14, 2025, during refueling outage RF-23, leakage past SWP-MOV57A was 7.59 gpm. Inspectors observed that this condition was determined not to be a maintenance rule functional failure by the licensee. The licensee provided the evaluation for the maintenance rule functional failure determination. This evaluation credited compensatory actions to restore inventory to the standby service water system via alternate sources.
Compensatory actions are only credited for operability considerations and cannot be applied to maintenance rule functional failure determinations. This is clear in the licensees procedure EN-DC-205, Revision 10, Maintenance Rule Monitoring, Attachment 2, Guidelines for Functional Failure Determination, item 2, which states Maintenance Rule monitoring is for the intended function of the SSC and should not take credit for operator actions unless these actions are intended by the design. If operator actions are compensatory actions required to maintain the equipment, then this may be considered a failure of the SSC.
The seat leakage of SWP-MOV57A should have been considered in the absence of compensatory actions and therefore would have represented a maintenance rule functional failure (MRFF). This MRFF should have shifted the standby service water system from the a(2) to the a(1) maintenance rule category with additional monitoring and plans required to restore the system performance to acceptable standards had the licensee established appropriate condition monitoring performance criteria.
Corrective Actions: The licensee entered this condition in the corrective action program. No operability determination was required since compensatory actions were already established to support operability of the standby service water system.
Corrective Action References: CR-RBS-2025-05265
Performance Assessment:
Performance Deficiency: The licensee failed to monitor the performance or condition of the standby service water system volume in a manner sufficient to provide reasonable assurance that these structures, systems, and components are capable of fulfilling their intended functions in accordance with 10CFR50.65(a)(1). Specifically, the licensee failed to identify that the maintenance rule condition monitoring criteria was exceeded when SWP-MOV57A exceeded the allowed leakage during testing as documented by CR-RBS-2025-00779.
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 failure to identify a maintenance rule functional failure resulted in not performing additional assessments and establishing goals to return the system performance to an acceptable level.
Significance: The inspectors assessed the significance of the finding using IMC 0609 Appendix A, The Significance Determination Process (SDP) for Findings At-Power.
Inspectors used Exhibit 2, "Mitigating Systems Screening Questions," and determined that the issue screened to Green because the SSC retained its operability or PRA functionality.
Specifically, the standby service water system was considered operable due to compensatory measures that establish makeup from alternate sources to achieve the 30-day mission time.
Cross-Cutting Aspect: P.2 - Evaluation: The organization thoroughly evaluates issues to ensure that resolutions address causes and extent of conditions commensurate with their safety significance. Inspectors reviewed corrective actions for a similar NRC violation that was issued recently for maintenance rule discrepancies. The licensee performed an apparent cause determination under CR-RBS-2024-05326 and implemented several corrective actions.
However, no extent of condition was performed to look at other maintenance rule functional failures outside of the ones identified by the NRC. This was a missed opportunity to discover other maintenance rule evaluations which may have been performed erroneously.
Enforcement:
Violation: 10CFR50.65(a)(1) requires in part that licensees shall monitor the performance or condition of structures, systems, or components, against licensee-established goals, in a manner sufficient to provide reasonable assurance that these structures, systems, and components, are capable of fulfilling their intended functions. Such goals shall be established commensurate with safety.
Contrary to the above, from February 14, 2025, to September 25, 2025, the licensee did not monitor the performance or condition of structures, systems, or components, against licensee-established goals, in a manner sufficient to provide reasonable assurance that these structures, systems, and components, are capable of fulfilling their intended functions.
Specifically, the preventative maintenance program for the standby service water system was shown to be ineffective due to repeat maintenance preventable functional failures of SWP-MOV57A due to excessive seat leakage.
Enforcement Action: This violation is being treated as a non-cited violation, 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 25, 2025, the inspectors presented the River Bend Station Age-Related Degradation Inspection results to Phil Hansett, 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
CR-RBS-
25-04386, 2025-03716, 2025-01383, 2025-00836,
25-00779, 2025-00390, 2024-04957, 2023-00433,
23-02997, 2023-01889, 2023-02815
Corrective Action
Documents
Resulting from
Inspection
CR-RBS-
25-04966, 2025-05003, 2025-05007, 2025-05008,
25-05012, 2025-05014, 2025-05015, 2025-05023,
25-05024, 2025-05034, 2025-05251, 2025-05037
EE-001M
4160V One Line Diagram, Standby Bus E22-S004
EE-001SA
480V One Line Diagram, 1E22*S002 Control Building
EE-001TA
480V One Line Diagram, EHS-MCC2A & 2L Auxiliary
Building
ESK-06HVR12
Elementary Diagram, 480V Control Circuit Auxiliary
Building Unit Coolers UC4 & UC6
PID-09-10B
Engineering P&I Diagram, System 118, Service Water-
Normal
Drawings
PID-09-10E
Engineering P&ID System 256 Service Water - Standby
Engineering
Changes
SBCT Sparger Pipe Modifications
21.452-000-
003
Purchase Specification For Turbine, Steam, Auxiliary
Drive
21.243-000-
003F
Installation and Maintenance Manual for Explosive Valves
07/12/1996
24.110-000-
030A
Operating and Maintenance Instructions for Reactor Core
Isolation Cooling Systems
B
242.521-102-
001O
Magne-Blast Circuit Breaker Type AM-4.16-250-9
10/12/1992
242.521-102-
001Q
GE Metal-Clad Switchgear Type M26 & M36
10/12/1992
B515-0136
Installation and Maintenance of Axial Flow Fans
C41-VEXF004A
PM 500389621
PM Template / Maintenance Strategy
9/3/2025
71111.21N.04
Miscellaneous
Limitorque Valve Operator Model SMB/SB/SBD-000
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
Through 5 MOV and HBC Periodic Inspection
EQAR-075
Environmental Qualification Assessment Report For
Reactor Core Isolation Cooling Turbine Controls
PID-27-06A
Engineering P&ID System 209 Reactor Core Isolation
Cooling
T12107
PM Job Plan to Replace C41-VEXF004A/B (STANDBY
LIQ CNTRL PMP 1A/B DISCH HEADER EXPLOSIVE
VLV) explosive charge, firing assembly, and inlet fitting
after test firing.
11/13/2025
VTD-B455-0100
Asea Brown-Boveri Installation/Maintenance Instructions
for Medium-Voltage Power Circuit Breakers Type 5HK
200 Thru 3000 Amperes 5000 Volts
VTD-B455-0139
Brown Boveri (Now ABB Power T&D Company Inc.)
Instructions for Undervoltage and Over-Voltage Relays
ITE-27 and ITE-59
VTD-B515-0121
Buffalo Forge Installation and Operation Instructions For
Air Handling Cabinets
VTD-H127-0103
Manual for Standby Service Water Pumps
CMP-EM-302-
1003
GE 4.16KV Switchgear - Clean and Inspect
001
Site Procedure Control Process
2
Maintenance Rule Scope and Basis
009
Maintenance Rule Monitoring
010
Predictive Maintenance Program
Preventive Maintenance Program
2
STP-209-0601
RCIC Initiation Functional
Procedures
STP-209-6310
RCI Quarterly Pump and Valve Operability Test
Work Orders
WO- 54037374, 54070128, 54079785, 54096866, 54114035,
54142462, 54143414, 54175197, 54210808, 54225062,
275241, 00128314, 52330722, 52891357, 53005728,
53020629, 53038705, 54045762, 54053010, 54087830,
54093435, 54118674, 54124859, 54148924, 54154000,
54181620, 54187952, 51008285, 52996077, 53019106,
53020105, 54039054, 54057906, 54078168, 54105055,
Inspection
Procedure
Type
Designation
Description or Title
Revision or
Date
54135956, 54161299, 54203356, 54235137, 54266581,
250898