05000382/LER-2025-003, Auxiliary Component Cooling Water Train Inoperable Resulting in a Condition Prohibited by Technical Specifications
| ML25160A203 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 06/09/2025 |
| From: | Twarog J Entergy Operations |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| W3FI-2025-0025 LER 2025-003-00 | |
| Download: ML25160A203 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3822025003R00 - NRC Website | |
text
Digitally signed by John R. Twarog DN: cn=John R. Twarog, o=Entergy, ou=Waterford 3 Regulatory Assurance, email=jtwarog@entergy.com Date: 2025.06.09 09:41:03 -05'00' John R.
Twarog E) entergy W3F1-2025-0025 June 09, 2025 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001 John Twarog Manager Regulatory Assurance 504-739-6747 10 CFR 50.73
Subject:
Licensee Event Report 50-382/2025-003-00, Auxiliary Component Cooling Water Train Inoperable Resulting in a Condition Prohibited by Technical Specifications Waterford Steam Electric Station, Unit 3 NRC Docket No. 50-382 Renewed Facility Operating License No. NPF-38 Entergy Operations, Inc. (Entergy) submits the enclosed Licensee Event Report (LER) 50-382/2025-003-00 for Waterford Steam Electric Station, Unit 3 (WF3). The event reported herein is reportable in accordance with 10 CFR 50.73(a)(2)(i)(B), Operation or Condition Prohibited by Technical Specifications.
This letter contains no new commitments.
Should you have any questions concerning this issue, please contact me at 504-739-6747.
Respectfully, John Twarog JRT/rrp Entergy Operations, Inc., 17265 River Road, Killona, LA 70057
W3F1-2025-0025 Page 2 of 3 Enclosure: LER 50-382/2025-003-00 cc:
NRC Region IV Regional Administrator NRC Senior Resident Inspector - Waterford Steam Electric Station, Unit 3 NRC Project Manager-Waterford Steam Electric Station, Unit 3 Louisiana Department of Environmental Quality
Enclosure W3F1-2025-0025 Licensee Event Report 50-382/2025-003-00
Abstract
On April 10, 2025, Waterford Steam Electric Station, Unit 3 started the performance of a planned surveillance test on Auxiliary Component Cooling (ACC) Pump A An oil leak of approximately 150 to 200 drops per minute was identified where the pump shaft goes into the inboard bearing housing. ACC Pump A was declared inoperable and an entry into Technical Specification (TS) 3. 7.3, 72-hour Action Statement, was made. Following maintenance, the pump was restarted on April 10, 2025 with no oil leakage observed. Operations secured ACC Pump A and restarted it again on April 11, 2025, and similar oil leakage as the previous day was identified. The pump's oil reservoir vent caps were replaced, two subsequent runs were performed with no oil leakage, and ACC Pump A was declared operable on April 12, 2025. ACC Pump A was removed from service on April 16, 2025, to conduct additional inspections. An oil passage was found to be partially blocked and foreign material was present in the oil passage to the outboard bearing of the pump. An engineering evaluation determined the as-found condition could have impacted ACC Pump A operability, resulting in a condition prohibited by TS. This report is being made in accordance with 10 CFR
- 50. 73(a)(2)(i)(B).
The cause was attributed to inadequate worker practices (legacy) and ineffective actions taken from a previous ACC pump bearinq failure investiciation.
=
Background===
- 2. DOCKET NUMBER
- 3. LER NUMBER YEAR SEQUENTIAL REV [2025 [
NUMBER NO.
00382 I
I G 003 Waterford Steam Electric Station, Unit 3 (WF3) has two Auxiliary Component Cooling (ACC) pumps that support the Component Cooling Water/ Auxiliary Component Cooling Water systems. The function of the Component Cooling Water/ Auxiliary Component Cooling systems is to provide sufficient cooling capacity to support continued operation of safety related equipment during normal and accident conditions. The auxiliary component cooling water pumps, one pump per train, circulate sufficient water from the ultimate heat sink (UHS) through the components to be cooled such that the design normal and accident heat loads can be removed.
Technical Specification (TS) 3.7.3, Component Cooling Water and Auxiliary Component Cooling Water Systems, requires at least two independent component cooling water and associated auxiliary component cooling water trains to be operable in Modes 1, 2, 3, and 4. The Action Statement states: With only one component cooling water and associated auxiliary component cooling water train OPERABLE, restore at least two trains to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or in accordance with the Risk Informed Completion Time (RICT) Program or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
Event Description
On April 10, 2025, at 1011 CDT, ACC Pump A was started to support performance of OP-903-050, Component Cooling Water & Auxiliary Component Cooling Water Pump and Valve Operability Test. An oil leak of approximately 150-200 drops per minute was identified from the pump's inboard bearing housing and the pump was secured and declared inoperable.
Based on previous operating experience, the oil reservoir vent caps were cleaned. ACC Pump A was restarted, and no oil eakage was observed. ACC Pump A was secured with a plan to start the pump the following day to ensure the leakage would not be present.
On April 11, 2025, at 1250 CDT, ACC Pump A was started, and oil leakage was present at the previous location. The pump was secured and both vent caps were replaced with new caps. Two subsequent runs were completed, with no oil leakage identified, and ACC Pump A was declared operable on April 12, 2025 at 0220 CDT.
On April 16, 2025, following discussions with industry pump experts and EPRI, ACC Pump A was removed from service o perform additional inspections of its oil system. The inspections found foreign material, suspected to be gasket material, in an oil supply line to the pump's outboard bearing and a partially blocked oil line to the oil cooler. The oil lines were cleared and the gasket that partially blocked one of the lines was removed and replaced. ACC Pump A was returned to service and declared operable on April 17, 2025 at 0800 CDT.
An engineering evaluation completed on May 5, 2025 determined that ACC Pump A had been inoperable from April 10, 2025 to April 17, 2025. WF3 had not implemented RICT during that period between April 10, 2025 and April 17, 2025. The duration of this inoperability period exceeded the allowable outage time, 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, specified in WF3's TS while in the Mode of Applicability; therefore, WF3 operated in a condition prohibited by TS.
Event Cause
The investigation identified the direct cause for the oil leakage from ACC Pump A and subsequent inoperability was due to a gasket partially blocking an oil passage and the presence of foreign material in the oil passage. Causal factors for this event include; (1) Inadequate worker practices associated with the improperly installed gasket, legacy issue for ACC Pump A and (2) Ineffective actions from previous ACC Pump bearing failure (2008).
Safety Assessment
There were no radiological, environmental, or industrial impacts associated with this event. The health and safety of the public and site personnel were not impacted during this event. At least one train of Component Cooling Water and Auxiliary Component Cooling Water remained operable during the period of ACC Pump A inoperability.
Corrective Actions
(1) Disassembled ACC Pump A bearings, removed oil lines, gasket obstructions, and foreign material.
(2) Develop Maintenance and Engineering Department "Lessons Learned" and communicate them to the departments.
(3) Create work order to implement EC 16012 to remove oil reservoir vent cap filter material (4) Revise MM-006-025, Component Cooling Water Maintenance, to include this OE and steps to clean and inspect the oil system under additional conditions.
(5) Completed inspection of ACC Pump B to ensure a similar condition does not exist.
Previous Similar Events
(1) January 30, 2008 -ACC Pump B was started for retest following maintenance. Both inboard and outboard bearing temperatures found rising rapidly. Both bearings were inspected and found wiped due to inadequate lubrication.
Contributing causes were presence of foreign material in the outboard bearing housing.
(2) October 16, 2013 -ACC Pump B, has oil leaks from the inboard bearing housing and/or the 2 inch oil return cross connection line fittings.
(3) March 1, 2018 - ACC Pump B has approximately 15 drops per minute oil leak from both sides of the pump inboard bearing housing. Bearing oil level is in band. Page 3
of 3