05000423/LER-2023-005, Oil Leakage from C RSS Pump Motor Challenged Meeting Its Mission Time Resulting in a Condition Prohibited by Technical Specifications
| ML24039A186 | |
| Person / Time | |
|---|---|
| Site: | Millstone  (NPF-049) |
| Issue date: | 02/08/2024 |
| From: | O'Connor M Dominion Energy Nuclear Connecticut |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 24-067 LER 2023-005-00 | |
| Download: ML24039A186 (1) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 4232023005R00 - NRC Website | |
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Dominion Energy Nuclear Connecticut, Inc.
Millstone Power Station 314 Rope Ferry Road, Waterford. CT 06385 DominionEnergy.com U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 FEB O 8 2024 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
MILLSTONE POWER STATION UNIT 3 LICENSEE EVENT REPORT 2023-005-00 A Dominion ii? Energy Serial No.:
24-067 MPS Lie/JP RO Docket No.: 50-423 License No.: NPF-49 OIL LEAKAGE FROM "C" RSS PUMP MOTOR CHALLENGED MEETING ITS MISSION TIME RESULTING IN A CONDITION PROHIBITED BY TECHNICAL SPECIFICATIONS This letter forwards Licensee Event Report (LER) 2023-005-00, documenting a condition that was discovered at Millstone Power Station Unit 3 (MPS3) on December 10, 2023. This LER is being submitted pursuant to 10 CFR 50.73 (a)(2)(i)(B) as a condition prohibited by technical specifications.
There are no regulatory commitments contained in this letter or its enclosure.
Should you have any questions, please contact Mr. Dean E. Rowe at (860) 444-5292.
Sincerely, lJL='-~~
Michael J. O'Connor Site Vice President - Millstone Enclosure: LER 423/2023-005-00
Serial No.24-067 Docket No. 50-423 Licensee Event Report 2023-005-00 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region I 475 Allendale Road, Suite 102, King of Prussia, PA 19406-1415.
R. V. Guzman NRC Project Manager Millstone Units 2 and 3 U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 08 C2 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector Millstone Power Station
Serial No.24-067 Docket No. 50-423 Licensee Event Report 2023-005-00 ATTACHMENT LICENSEE EVENT REPORT 2023-005-00 OIL LEAKAGE FROM "C" RSS PUMP MOTOR CHALLENGED MEETING ITS MISSION TIME RESULTING IN A CONDITION PROHIBITED BY TECHNICAL SPECIFICATIONS MILLSTONE POWER STATION UNIT 3 DOMINION ENERGY NUCLEAR CONNECTICUT, INC.
Abstract
On December 10, 2023 with Millstone Power Station Unit 3 (MPS3) at 47% power, while performing routine monthly surveillance SP 3670.4, Monthly PMs, it was observed that the motor upper bearing oil level for the Unit 3 C containment recirculation spray system pump (3RSS*P1C) was found below the allowable acceptance criteria. Past operability was reviewed, and it was concluded that with the reduced oil level and leak at the upper motor bearing, the C RSS pump may not have been capable of performing its safety function to meet its mission time requirement. The direct cause was oil leakage past the O-ring of the upper motor bearing sight glass. Oil additions were made and upper sight glass assembly with O-rings were replaced. This condition is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), any operation or condition prohibited by the plant's Technical Specifications.
BE B
MO W120 YPage of
- 3. LER NUMBER YEAR SEQUENTIAL NUMBER REV NO.
052 050 4
4 Millstone Power Station - Unit 3 00423 2023 005 00
CORRECTIVE ACTIONS
The condition was corrected by replacing the C RSS pump upper sight glass assembly and O-rings on January 13, 2024.
No leakage has been observed since the replacement. Additional corrective actions will be taken in accordance with the stations Corrective Action Program.
PREVIOUS OCCURRENCES
There have been no similar events or conditions where Unit 3 Containment recirculation spray system was outside the Technical Specification over the last 5 years.
ENERGY INDUSTRY IDENTIFICATION SYSTEM (EIIS) CODES BE Containment Spray System LG Sight Glass Level MO Motor