PNO-III-06-012, A: Kewaunee: Manual Reactor Shutdown Following Feedwater Pump Trip (Update)
| ML061370315 | |
| Person / Time | |
|---|---|
| Site: | Kewaunee  |
| Issue date: | 05/17/2006 |
| From: | Louden P NRC/RGN-III |
| To: | |
| References | |
| PNO-III-06-012A | |
| Download: ML061370315 (2) | |
May 17, 2006PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PNO-III 012AThis preliminary notification constitutes EARLY notice of events of POSSIBLE safety or publicinterest significance. The information is as initially received without verification or evaluation, and is basically all that is known by the Region III staff on this date. FacilityKewauneeDominion Energy Kewaunee, Inc.
Docket: 50-305 License: DPR-43Licensee Emergency Classification Notification of Unusual Event x Alert Site Area Emergency General Emergency Not Applicable
SUBJECT:
MANUAL REACTOR SHUTDOWN FOLLOWING FEEDWATER PUMP TRIP (UPDATE)DESCRIPTION:
On April 26, 2006, operators manually tripped the reactor when the A feedwater pumpunexpectedly tripped. At the time, operators were reducing reactor power in preparation for a maintenance outage. Since the B feedwater pump was already shut down, the tripping of theoperating pump should have caused a turbine trip followed by a reactor trip. When the turbine did not trip, operators took manual action to shut down the reactor, which tripped the turbine. The licensee has determined that the cause of the trip of the A feedwater pump was a switch inthe cubicle of the breaker for the B feedwater pump that had not repositioned properly. Thelicensee identified that the mispositioned switch was caused by an improperly adjusted mechanical linkage in the cubicle. The linkage was subsequently repaired. The licensee examined other breaker cubicles and had to make only minor adjustments tolinkages in some of the cubicles for nonsafety-related equipment. Procedures for maintenance of the cubicles will be revised to include specifications for linkage adjustments. NRC inspectorsreviewed these planned corrective actions and found them appropriate. An NRC Special Inspection Team reviewed the circumstances surrounding the event and thelicensee's evaluation of the cause. The inspection team agreed with the results of the evaluation and concluded that reactor operators responded appropriately to the unexpected tripof the A feedwater pump. The declaration of the Alert was also determined by the inspectors to have been appropriate. The results of the NRC's special inspection will be issued in aninspection report in about 45 days. The licensee is making plans to restart the plant.
The State of Wisconsin will be informed. The information in this preliminary notification hasbeen reviewed with licensee management.This information is current as of 8:00 a.m. (CDT) on May 17, 2006.
CONTACT:Patrick Louden630/829-9627