Event Notification Report for June 16, 2003

VALID FEEDWATER ISOLATION SYSTEM SIGNAL GENERATED

A valid feedwater isolation signal (FWIS) was generated while controlling steam generator water level near 82% wide range during heat-up activities to take the plant from Mode 4 to Mode 3. The set point for FWIS is 67% narrow range, which is relatively close to the 82% wide range the plant was being controlled. Level was allowed to get slightly higher which activated the FWIS. No isolation occurred as the valves were already closed and level was being maintained with auxiliary feedwater. Level has been restored to less than the set point.

The licensee notified the NRC Resident Inspector.

LOSS OF SAFETY PARAMETER DISPLAY SYSTEM FOR GREATER THAN 8 HOURS

"At 0743 CDT on June 16, 2003, the Safety Parameter Display System (SPDS) was out of service for greater than eight hours due to the loss of the Nuclear Steam Supply (NSS) Computer, which provides the computer points for SPDS.

"10CFR50.72(b)(3)(xiii), which states 'the licensee shall notify the NRC as soon as practical and in all cases
within 8 hours of the occurrence of any event that results in the major loss of emergency assessment capability.'

"The loss of SPDS is considered a major or loss of safety assessment capability. The site defines a 'major loss'
of SPDS, 'when the SPDS function is not available in the control room for greater than eight hours.' This is
consistent with NUREG-1022, EVENT REPORTING GUIDELINES 10CFR 50.72 and 50.73 section 3.2.13,
Loss of Emergency Preparedness Capabilities. The NSS Computer went down at 2343 on June 15, 2003 (CDT).
The eight-hour unavailability of SPDS expired at 0743 on June 16, 2003 (CDT). Repair efforts have been
underway continuously to restore the NSS Computer and return SPDS to service. The expected return to
service for SPDS is on June 16, 2003. All other plant conditions are normal."

The licensee has notified the NRC Resident Inspector.

INABILITY TO ACTIVATE EMERGENCY SIRENS DUE TO EQUIPMENT FAILURE

"It was discovered on 6/16/03 at 0755 that the plant sirens (Prompt Alert Notification System) were out of service since Sunday 6/15/03 at 0757 [the cause appears to be a continuous signal being transmitted by a siren]. The system was restored to service at 0830 on 6/16/03."

The licensee notified local authorities, the State and the NRC Resident Inspector.

Similar incidents involving emergency sirens have been reported on 6/10/03 (See EN #39912) and on 6/11/03 (See EN # 39918).

4-HOUR REPORTABLE INCIDENT FOR WHICH A PRESS RELEASE WAS MADE

"A fluorine gas release occurred in the C-410K facility while operators were charging the gas system. The released gas caused a reaction which consumed a small section of the gas system piping. No detectable quantities of the gas were measured outside the affected facility. The Emergency Action Level classification criteria for fluorine releases was not met. The release was isolated by facility operators. The media requested information from the plant concerning the release and the plant provided a verbal statement. This statement constituted a 'media/press release' which required a 4 hour notification to the NRC as required by plant procedure UE2-RA-RE1030, 'Nuclear Regulatory Event Reporting'.

"The NRC Senior Resident Inspector has been notified of this event."

UNEXPECTED ISOLATION SIGNAL DURING TESTING WHICH RESULTED IN A MOMENTARY LOSS OF SHUTDOWN COOLING

"This event notification is being made to report an event that could have prevented the fulfillment of the safety function to remove residual heat. On June 16, 2003, the plant was shutdown in Mode 4 with reactor vessel level being maintained between 60-120 inches. Operators were performing surveillance testing on the manual pushbutton isolation logic to the Nuclear Steam Supply Shutoff System when an unexpected general outboard isolation signal was received. This resulted in the closure of RHR-V-8 (RHR shutdown cooling outboard containment isolation valve) and the interruption of shutdown cooling. Reactor Recirculation Pump B remained in service providing forced flow through the reactor core. Operators restored from the surveillance, reset the isolation signal, and reopened RHR-V-8. Shutdown cooling was restored 12 minutes after RHR-V-8 went closed. Reactor vessel level and temperature remained stable during the period shutdown cooling was not in service."

The licensee's incident and review board determined that the procedure was deficient in that it did not alert operators to the isolation signal which functioned as required. The licensee will inform the NRC resident inspector.