05000317/LER-2002-003, Re Reactor Trip Due to Loss of Reactor Coolant Pump Motor Oil
| ML022630111 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 09/17/2002 |
| From: | Nietmann K Constellation Energy Group |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| LER-02-003-00 | |
| Download: ML022630111 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 3172002003R00 - NRC Website | |
text
Kevin J. Nietmann Plant General Manager Calvert Cliffs Nuclear Power Plant Constellation Generation Group, LLC 1650 Calvert Cliffs Parkway Lusby, Maryland 20657 410 495-4101 410 495-4787 Fax Constellation Energy Group September 17,2002 U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:
SUBJECT:
Document Control Desk Calvert Cliffs Nuclear Power Plant Unit No. 1; Docket No. 50-317; License No. DPR 53 Licensee Event Report 2002-003 Reactor Trip Due to Loss of Reactor Coolant Pump Motor Oil The attached report is being sent to you as required under 10 CFR 50.73 guidelines. Should you have questions regarding this report, we will be pleased to discuss them with you.
Very truly yours, for Kevin J. Nietmarn Plant General Manager KJN/MJY/bjd Attachment cc:
J. Petro, Esquire J. E. Silberg, Esquire Director, Project Directorate I-1, NRC D. M. Skay, NRC H. J. Miller, NRC Resident Inspector, NRC R. I. McLean, DNR (1/
Abstract
On July 24, 2002, at approximately 1338 hours0.0155 days <br />0.372 hours <br />0.00221 weeks <br />5.09109e-4 months <br />, Unit 1 received a low level alarm on 11A Reactor Coolant Pump (RCP) motor upper bearing oil reservoir. At approximately 1620 hours0.0188 days <br />0.45 hours <br />0.00268 weeks <br />6.1641e-4 months <br />, Unit 1 Control Room Supervisor ordered a rapid downpower of Unit 1 in response to indications of increasing RCP motor thrust bearing temperatures. At 1628 hours0.0188 days <br />0.452 hours <br />0.00269 weeks <br />6.19454e-4 months <br />, the Unit 1 Control Room Supervisor ordered a manual trip of Unit 1 when 11 A RCP motor thrust bearing temperature reached 195 degrees Fahrenheit, in accordance with plant operating instructions.
Unit 1 was manually tripped and all systems responded satisfactorily, with the exception of a turbine bypass valve, which closed slowly, causing Unit 1 Steam Generator pressures to approach the point of operator action to shut the main steam isolation valves.
This event was caused by the failure of a butt weld on an RCP motor oil cooler line. The weld failure resulted in a through-wall crack that allowed lubricating oil to drain from the reservoir.
This loss of oil resulted in oil starvation of the thrust bearing and subsequent overheating of the RCP motor thrust bearing.
NRC FRKM 366j if-2M)1
I (If more space is required, use additional copies of (If more space is required, use additional copies of (If more space is required, use additional copies of NRC Form 366A)
V.
ADDITIONAL INFORMATION
A.
Component Identification IEEE 803 IEEE 805 Component EIIS Function System ID Reactor Coolant Pump Motor I 1A MO AB RCP Motor 11 A Oil Retum Line PSF AB B.
Calvert Cliffs Nuclear Power Plant has not experienced any similar reactor trips or reportable events due to RCP motor oil leakage or bearing failures. A forced outage occurred on October 25, 2001 due to a similar weld related failure on a component cooling water line to the 22A RCP motor upper bearing oil cooler. Ineffective corrective actions taken after the October 2001 event have been identified as contributing to the current event.
C.
Energy Industry Identification System (EIIS) component function identifier and system names of each component or system referred to in this licensee event report are as follows:
Component EIIS Function EIIS System ID Turbine Bypass Valve (1-TBV-3940)
V JIl RCP Oil Reservoir Level Transmitter LT AB Main Steam Isolation Valve ISV TA Component Cooling Water Piping PSF CC