05000424/LER-2005-003, Re Feedwater Valve Failure Leads to Reactor Trip
| ML051810231 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 06/27/2005 |
| From: | Grissette D Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-05-1074 LER 05-003-00 | |
| Download: ML051810231 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| 4242005003R00 - NRC Website | |
text
Don E. Grissette Vice President Southern Nuclear Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Tel 205.992.6474 Fax 205.992.0341 SOUTHERN A COMPANY June 27, 2005 Energy to Serve Yo Docket No.:
50-424 NL-05-1074 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant - Unit I Licensee Event Report 1-2005-003 Feedwater Valve Failure Leads to Reactor Trip Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.73, Southern Nuclear Operating Company hereby submits a Vogtle Electric Generating Plant licensee event report for a condition that was determined to be reportable on April 29, 2005.
This letter contains no NRC commitments. If you have any questions, please advise.
Sincerely, G
tt Don E. Grissette rrWorld"'
DEG/RJr/daj Enclosure: LER 1-2005-003 cc:
Southern Nuclear Operating Company Mr. J. T. Gasser, Executive Vice President Mr. T. E. Tynan, General Manager - Plant Vogtle RType: CVC7000 U. S. Nuclear Repgulatorv Commission Dr. W. D. Travers, Regional Administrator Mr. C. Gratton, NRR Project Manager - Vogtle Mr. G. J. McCoy, Senior Resident Inspector-Vogtle
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Abstract
On April 29, 2005, operators responded to closure of loop I feed water regulating valve, IFV-5 10, by taking manual control in accordance with the abnormal operating procedure. Trouble shooting determined the cause to be a failed controller card. Replacement of the failed card was initiated in accordance with a card replacement procedure.
During maintenance, the loop I feedwater regulating valve unexpectedly shut. As steam generator water level approached the low-low setpoint, operators took action to trip the reactor. However, an automatic reactor trip on low-low steam generator water level occurred 1/4 second before the manual trip at 2155 EDT. Operators responded properly to stabilize the plant at normal operating temperature and pressure in Mode 3 (Hot Standby).
The causes of this event were: a) technical inaccuracies and incomplete information in the procedure used for controller card replacement, and b) inadequate technician training regarding replacement procedure limitations for recent design changes. The failed card was replaced and the unit returned to power. Further corrective actions have been taken to clarify the procedure for intended purpose and limitations and to clarify technical training for the intended purpose of the procedure. Corrective actions are in progress to revise procedures to include replacement directions for the card failure that was experienced and train appropriate personnel on the replacement procedure for the failure that was experienced.
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(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)
G) ADDITIONAL INFORMATION I) Failed Components:
Controller card IFC-5 10 manufactured by Westinghouse Electric Corporation.
Type/Model # NCB1/2038A30G01.
- 2) Previous Similar Events:
There have been no previous similar events in the past three years.
- 3) Energy Industry Identification System Code:
Main Feedwater System - SJ Auxiliary Feedwater System - BA