Event Notification Report for April 28, 2004

UNUSUAL EVENT DECLEARED DUE TO AN ELECTRICAL FAILURE IN A NON-VITAL LOAD CENTER LOCATED IN THE UNIT 2 REACTOR BUILDING

On 04/28/04 at 1325 EDT, Susquehanna declared an Unusual Event due to an electrical failure in a power distribution panel at a non-vital load center located in the Unit 2 Reactor Building. The affected load center supplies electrical power to the Main Condenser Vacuum system causing plant operations to be reduced to 80% reactor power. Unit 1 has not been affected by this incident and Unit 2 remains stable at 80% reactor power.

The licensee terminated the Unusual Event at 1552 and is investigating the cause of the incident which appears to have been a phase-to-phase fault on the 13.8 KV load center feeder cable. Currently, load center 2B250 is being fed through an alternate feeder so that associated systems can be placed back in service. Unit 2 is making preparations to return to full power. There were no personnel injuries nor radioactive releases as a result of this event.

The licensee notified the NRC Resident Inspector, Luzerne and Columbia county emergency management agencies, the Pennsylvania Emergency Management Agency and has issued a press release.

Notified the following of the termination of the Unusual Event: R1DO(Barkley), DIRO (Frant), NRR (Marsh), DHS (E. McDonald) and FEMA (D. Barden).

CONTROL ROOM HVAC INOPERABLE

"During routine alignment of the Control Room HVAC system it was determined the 2/3-5741-053B damper failed to close as required. The damper is required to close to isolate outside air to the control room for accident conditions.

"Because of the damper failure the Control Room Emergency Ventilation System (CREVS) was declared inoperable at 1209 on 4/28/04.

"The CREVS is a single train system utilized to mitigate the consequences of an accident and this event is reportable under 10 CFR 50.72(b)(3)(v)(D). (Exelon Reportability Manual Section - SAF 1.8)"

The licensee notified the NRC Resident Inspector.

MANUAL REACTOR SCRAM DUE TO SPURIOUS TRIP OF 2A REACTOR RECIRCULATION MG AND PUMP

"On 4/28/04 at 1536 [CDT], Dresden Unit 2 experienced a trip of the 2A Recirc MG set and associated recirc pump. This placed the unit in the immediate scram region of the power to flow map. The Unit NSO manually scrammed the reactor in accordance with the immediate operator actions of DOA 202.01.

"Troubleshooting is in progress to determine the cause of the 2A Recirc MG set trip. There were no Electromatic Relief or Safety Relief Valve actuations. There were no ECCS initiations. PCIS Group 2 and Group 3 Isolations occurred as expected due to normal reactor water level decrease following the scram. All systems responded as expected following the reactor scram.

"This report is being made in accordance with 10 CFR 50.72 (b)(2)(iv)(B) for an actuation of the RPS and 10 CFR 50.72(b)(3)(iv)(A) for Group 2 and 3 actuations."

All control rods fully inserted, the electrical grid is stable, ECCS and the EDGs remain operable. The licensee notified the NRC Resident Inspector.

HPCI SYSTEM INOPERABLE FOLLOWING PLANNED MAINTENANCE

"During post maintenance testing following a High Pressure Coolant Injection (HPCI) System outage, the HPCI System was not declared operable due to unstable operation - oscillations of turbine speed (300-400 RPM), pump flow (600 GPM) and discharge pressure (300-550 psig) were seen in both automatic and manual flow control during the System Operability Periodic Test. HPCI had been declared inoperable at 0410 on 4/28/04 and placed under clearance to support planned maintenance on the Flow Controller, Flow Transmitter, system valves and condensate pump. The cause of the unstable operation is currently being investigated."

The licensee notified the NRC Resident Inspector.

* * * * RETRACTION FROM S. TABOR TO M. RIPLEY AT 1423 ET ON 5/28/04 * * * *

"On April 28, 2004, at 0410 hours, the High Pressure Coolant Injection (HPCI) system was declared inoperable to support scheduled maintenance on the HPCI system. To satisfy post maintenance test requirements and support restoring the HPCI system to an operable status, surveillance test, OPT-09.2, "HPCI System Operability Test," was performed. During this testing at 2230 hours, oscillations in pump flow, pressure, and turbine speed were observed in both the automatic and manual flow control modes of operation. Based on the test results, HPCI remained inoperable until the cause of the oscillations could be identified, corrective actions implemented, and the system satisfactorily tested. On April 29, 2004, at 0140 hours, the NRC was conservatively notified (Event Number 40714), in accordance with 10 CPR 50.72(b)(3)(v)(D), of a condition that at the time of discovery could have prevented the fulfillment of the HPCI safety function.

"Troubleshooting determined that the HPCI flow controller to the 2-E41-C002-CNV Ramp Generator Signal Converter (RGSC) was subject to spurious deviations. The RGSC was removed from its installed position and bench tested. Circuit review and testing determined that electronic component degradation was the most likely cause of the RGSC output signal perturbations. A new RGSC was calibrated and installed. After installation, in place testing showed that the new ramp generator did not exhibit signal variations. A final HPCI system operability test was performed and verified that the HPCI system was responding normally. On May 1, 2004, at 1220 hours, the HPC1 system was restored to service.

"Reportability Discussion:
NUREG-1022, Rev. 2, Section 3.2.7 (page 56) lists types of events or conditions that are generally not reportable under 10 CFR 50.72(b)(3)(v) and 10 CFR 50.73(a)(2)(v) criteria. The list of not-reportable conditions includes: Removal of a system or part of a system from service as part of a planned evolution for maintenance or surveillance testing when done in accordance with an approved procedure and the plant's TS (unless a condition is discovered that could have prevented the system from performing its function).

"On April 28, 2004, the HPCI system was removed from service to support a planned maintenance system outage. In addition, surveillance testing was performed to support system restoration following the maintenance outage for testing in accordance with an approved surveillance procedure. Based on the post maintenance test results, the HPCI system was declared inoperable and since the HPCI system is a single train safety system, an ENS notification was made. However, further evaluation of the condition determined that no condition was discovered that could have prevented the HPCI system from performing its functions. The following information provides the basis for that determination:

"Review of all applicable operating data collected during HPCI system testing performed from the time of discovery of the oscillation concern indicates that (1) the resulting HPCI speed spikes were in the positive direction and therefore no concern related to the inability of HPCI to provide adequate vessel level makeup existed, (2) the RGSC output perturbations followed a consistent pattern and the magnitude of the associated control problem would not have become more severe for a period longer than the assumed HPCI mission time, and (3) none of the excursions experienced were high enough to cause a system trip at the 5000 plus/minus 100 rpm overspeed trip setpoint. Even if a spurious speed spike resulted in a HPCI overspeed trip, the HPCI overspeed trip is designed to automatically reset and allow the system to ramp back up to operating speed. Given these facts, there was no observed performance that represented a loss of system function. Had HPCI been called upon to inject during the time that the condition resulting in HPCI flow oscillations existed, the system would have met all functional requirements.

"Carolina Power & Light Company, doing business as Progress Energy Carolinas, Inc., has determined that this event does not meet the 10 CFR 50.72 or 10 CFR 50.73 reporting criteria and the notification for Event Number 40714, is retracted. The resident inspector has been notified."

Notified R2 DO (R. Ayres).

MINOR WASTE POND LEAKAGE AT COGEMA MINING

The licensee reported the discovery of minor leaks detected in two of four surface evaporator waste ponds used as a portion of an uranium milling process. Each pond has a leak detection system which is checked once per week. The minor leaks were detected on 4/28/04 indicating some minor leakage through the pool liner. The licensee stated there was no release of liquid to the environment. Corrective actions planned are to pump down the two ponds and inspect and repair the liner as needed. This report was made pursuant to License Condition 11.4 which specifies to notify the NRC of any spills or leaks. The licensee also notified the Wyoming Department of Environmental Quality.

*****RETRACTED ON 4/30/04 AT 1115 FROM Nicholson TO LAURA*****

The licensee determined this event was not reportable because 10 CFR40.60 and 10 CFR20.2202 did not apply. The leakage was very minor and none was released to the environment.

Notified NMSS (J. Hickey) and R4DO (C. Marschall).