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| Entered date | Event description | |
|---|---|---|
| ENS 41537 | 28 March 2005 17:15:00 | The licensee faxed the following information: At 1248, 03/28/05, Callaway Plant notified the Missouri Public Service Commission (MPSC) of a forced outage expecting to last longer than three days. This notification was performed in accordance with 4CSR2403.190(3)(B). The information was supplied to the MPSC: * the plant shutdown occurred at 0520, 03/26/05 due to a minor leak in the Essential Service Water system, and that additional repairs were going, to be performed while shutdown. * the scope of the work addition had not been finalized and a formal restart date had not been established. This ENS notification is being made in accordance with 10CFR50.72(b)(2)(xi) for notification of another government agency. The licensee notified other governmental agencies and the NRC Resident Inspector. |
| ENS 41307 | 4 January 2005 18:32:00 | At 1230, 1/4/05, while performing a weekly test of alert sirens utilized in the prompt public notification system, it was determined that the twenty five sirens actuated by the Callaway County Emergency Operation Center (EOC) would not operate. There are a total of twenty nine alert sirens distributed among four counties and failure of the twenty five sirens actuated by Callaway County equates to a loss of 86.2 % of the alert sirens. During the period when the faulted sirens were unavailable, the back-up automated telephone calling service Community Alerting Network System (CANS) and the tone alert radio system were available and the Callaway County EOC was instructed to perform local route notifications as a backup method of notification. At 1345, 1/4/05, the twenty five Callaway County actuated sirens were restored and all twenty nine alert sirens were tested satisfactorily. Initial investigation indicates a computer software problem related to the feedback system. This caused a failure to occur in a circuit at the Callaway County radio tower and in the back-up manual system. The system vendor is researching the failure experienced and expects to provide a failure determination report by 1/5/05. Final corrective actions will be developed based upon the information provided by the vendor. The NRC Resident Inspector and local agencies were notified and the State will be informed.
The following information was provided by the licensee via facsimile: On 1/4/05, EN # 41307 was made from the Callaway Plant Control Room reporting 25 sirens actuated by the Callaway County Emergency Operations (EOC) would not operate. The Root Cause Analysis Team determined during their investigation that a siren failure did not occur. Analysis of the computer logs and interviews with the Callaway County Emergency Management Director (EMD) and the siren vendor revealed the sirens were not activated. Investigation by the siren manufacturer and testing of the siren system verified that the sirens would have sounded if they had been activated. Prior to activating the sirens, the county Emergency Management Director (EMD) attempted to poll the sirens. This poll locked up on the first siren. The EMD and the Siren Technician assumed the locked up polling of the sirens also locked up the siren activation program and therefore did not attempt to sound the sirens. Subsequent investigation by the siren manufacturer indicated that the sirens would activate even with the system polling function locked up. On 1/14/05, testing of the system in a locked up polling configuration confirmed that the sirens would have sounded if activated. As indicated in the previous notification, all sirens were successfully sounded at 1345 on 1/4/05, when given the first signal to activate. During an emergency activation, the written instruction direct that the sirens be activated without first polling the sirens. Personnel responsible for siren activation are not responsible for siren testing and would not have hesitated to activate the sirens, had there been an actual event. Therefore, a siren activation failure did not occur. The sirens remained capable of activation if required. This notification is being retracted. The NRC Resident Inspector, State, and local government agencies have been notified by the licensee. R4DO (Clark) was informed. |
| ENS 40500 | 3 February 2004 09:24:00 | AT 0439, 02/03/04, Callaway Plant experienced a reactor trip while operating transmission breakers located in the plant switchyard. Auxiliary feedwater actuated as expected to stabilize steam generator water levels. All other plant systems responded as expected. At present, the cause of the reactor trip is undetermined. Initial indications are that there were no voltage or frequency perturbations on the electrical grid. Plant staff is investigating potential areas in an effort to identify the cause of the trip. The main generator output breakers opened when one of the transmission breakers in the switchyard was opened per the scheduled maintenance test. When the incoming Transmission line breaker was opened it should not have caused the main generator output breakers to open. All rods fully inserted into the core. Both Motor Driven Auxiliary Feedwater pumps automatically started on a loss of both main feedwater pumps and the Turbine Driven Auxiliary Feedwater pump started on low low steam generator water level. The "C" Steam Generator atmospheric steam dump valve opened for about 17 seconds before it closed (no leaking steam generator tubes in the "C" Steam Generator). All Emergency Core Cooling systems are fully operable except for the "A" Safety Injection System. It was declared inoperable when it failed a valve test last night at 0205 CST. All Emergency Diesel Generators are fully operable. Turbine Driven Auxiliary Feedwater Pump discharge valves were closed after it had operator for about two hours. Approximately one hour after the valves were closed the Turbine Driven Auxiliary Feedwater pump tripped. This incident is being investigated. The NRC Resident Inspector was notified of this event by the licensee. |