05000325/LER-2003-001, Reactor Feed Pump Trip Results in Specified System Actuations
| ML030780769 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 03/13/2003 |
| From: | Noll W Carolina Power & Light Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| BSEP 03-0014 LER 03-001-00 | |
| Download: ML030780769 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| 3252003001R00 - NRC Website | |
text
gi CP&L A Progress Energy Company March 13, 2003 SERIAL: BSEP 03-0014 10 CFR 50.73 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NO. 1 DOCKET NO. 50-325/LICENSE NO. DPR-71 LICENSEE EVENT REPORT 1-03-001 Gentlemen:
In accordance with the Code of Federal Regulations, Title 10, Part 50.73, Progress Energy Carolinas, Inc. submits the enclosed Licensee Event Report. This report fulfills the requirement for a written report within sixty (60) days of a reportable occurrence.
Please refer any questions regarding this submittal to Mr. Edward T. O'Neil, Manager - Support Services, at (910) 457-3512.
Sincerely, W. G. Noll Plant General Manager Brunswick Steam Electric Plant CRE/cre Enclosure: Licensee Event Report Brunswick Nuclear Plant PO Box 10429 Southport, NC 28461 15~6De9)
Document Control Desk BSEP 03-0014 l Page 2 cc (with enclosure):
U. S. Nuclear Regulatory Commission, Region II ATTN: Mr. Luis A. Reyes, Regional Administrator Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW, Suite 23T85 Atlanta, GA 30303-8931 U. S. Nuclear Regulatory Commission ATTN: NRC Senior Resident Inspector 8470 River Road Southport, NC 28461-8869 U. S. Nuclear Regulatory Commission ATTN: Ms. Brenda L. Mozafari (Mail Stop OWFN 8G9) (Electronic Copy Only) 11555 Rockville Pike Rockville, MD 20852-2738 Ms. Jo A. Sanford Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-051
Abstract
On January 12, 2003, at approximately 1552 hours0.018 days <br />0.431 hours <br />0.00257 weeks <br />5.90536e-4 months <br />, decreasing reactor coolant level, due to a reactor feedwater pump turbine (RFPT) trip, resulted in the actuation of the reactor protection system (RPS), as well as Group 2 and Group 6 primary containment isolation valve closures. After the plant trip, the four emergency diesel generators (EDGs) started due to an invalid signal generated by switchyard equipment. In addition, the Reactor Core Isolation Cooling system was manually operated to maintain coolant level in the reactor vessel.
At the time of the event, Unit 1 was initially operating at 94 percent of rated thermal power.
The cause of the RPS and subsequent equipment actuations was attributed to the decrease in reactor vessel level caused by a RFPT 1B trip which was the result of insufficient lube oil pressure margin on the RFPT 1B bearing header during a Main Oil Pump (MOP) trip. With proper margin, the standby MOP would have been able to maintain bearing header oil pressure, thereby avoiding RFPT trip and the event. The cause of the automatic start of the EDGs is the failure of a Power Circuit Breaker (PCB) to open on its initial trip signal, which resulted in the invalid automatic EDG start signal. The safety significance of this occurrence is considered minimal.
RFPT 1B is being operated with both MOPs in operation until further investigation can be performed to resolve the rapid oil pressure decrease noted when an MOP is tripped in single MOP operation. The PCB was tested to ensure proper operation and returned to service.
NRC FORM 366 (7-2001)
(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 (If more space is required, use additional copies of (if more space is required, use additional copies of NRC Form 366A) (17)
COMMITMENTS
Those actions committed to by Progress Energy Carolinas, Inc. (PEC) in this document are identified below.
Any other actions discussed in this submittal represent intended or planned actions by PEC. They are described for the NRC's information and are not regulatory commitments. Please notify the Manager -
Support Services at BSEP of any questions regarding this document or any associated regulatory
commitments
During the next Unit 1 refuel outage (i.e., B115Rl), further investigation of the RFPT lB lubricating oil system will be conducted to determine the resolution of the issue associated with the rapid bearing header pressure decrease noted when a MOP trips in single MOP operation.
- By May 22, 2003, a multi-disciplined team will provide recommendations to improve the operation and reliability of the RFPT lubricating oil system. The recommendations will be implemented as appropriate.