Event Notification Report for October 19, 2004

INVALID TURBINE DRIVEN AUXILIARY FEEDWATER ACTUATION

"On October 19, 2004, McGuire Nuclear Station Unit 2 experienced an inadvertent actuation of the Turbine Driven Auxiliary Feedwater (TDCA) Pump. This event occurred when the steam supply valve to the pump failed open due to low pressure in the nitrogen supply to the valve's actuator. Further evaluation determined that the inadvertent actuation of the TDCA Pump was not in response to actual plant conditions or parameters satisfying the requirements for actuation of the pump. Since the TDCA Pump was not started in response to a valid signal, this represented an invalid actuation reportable per the requirements of 10 CFR 50.73 (a) (2) (iv) (A). However, as per 10 CFR 50.73(a)(1), McGuire is providing a telephone notification of this invalid actuation instead of submitting a written LER.

"The following additional information is being provided as part of the telephone notification of this event:
- The Unit 2 TDCA Pump actuated and injected water into all four of the Unit 2 Steam Generators
- The actuation of the Unit 2 TDCA Pump was successful and complete."

The licensee stated the total injection time was approximately 16 minutes and that a very small power increase was observed during the event.

The NRC Resident Inspector has been notified by the licensee.

UNUSUAL EVENT DECLARED DUE TO UNEXPLAINED DECREASE IN SPENT FUEL POOL WATER LEVEL

"An uncontrollable decrease in water level in the spent fuel pool occurred. All fuel assemblies remained covered. Current plant conditions DO NOT threaten public safety. Level decrease is secure. Valve lineup caused level decrease to BWST. Approximately 24 feet above fuel maintained. Secured fuel transfer canal drain lineup."

Unit 3 is currently defueled. The licensee was attempting to perform a spent fuel pool makeup while there was another valve lineup in progress which drained the deep end of the fuel transfer canal. This exposed some piping that allowed a flow path from the spent fuel pool to the BWST and resulted in the transfer of slightly less than 1 ft. level in the spent fuel pool, or approximately 10,000 gallons. Operators immediately recognized the decrease in spent fuel pool level and took appropriate steps to secure other activities in order to identify the drain path. This included securing the RCB wash downs in progress inside containment to eliminate a source for the observed increase in RB sump levels and secured equipment drain downs in progress in the Aux Building to eliminate these as a source for the observed increase in the high activity waste tank level.

Spent fuel pool level decreased from 0.3 ft above to about 0.7 ft below the normal. During the transient, a 24 ft. level was maintained above the spent fuel. No increase in radiation levels following the decreasing in water level was observed.

The licensee had recently started three spent fuel pool cooling pumps and due to a decrease in spent fuel pool temperature some shrinkage had occurred. The drain down to the BWST was initiated at approximately 2115 hours. At 2130 hours, Operators recognized the problem and entered the applicable Abnormal Procedure. At 2210 hours the Licensee declared an Unusual Event and took actions to secure the valve lineup which allowed the drain down. These actions were completed by 2215 hours at which time the Unusual Event was terminated. By 2224 hours a level increase due to makeup was observed.

Current spent fuel pool level is - 0.15 ft and increasing. The Licensee will continue makeup until the level reaches + 0.5 which is estimated to occur at approximately 0100 hours on 10/20/04. No offsite radioactive release occurred.

The licensee will inform the NRC resident inspector.

LOSS OF WELL LOGGING SOURCE OFF SHORE

During well logging operations on a fixed platform in the Gulf of Mexico, the well logging tool separated from the wireline and fell overboard in approximately 40 feet of water. The well logging tool has a 45 millicurie Cs-137 source attached. Licensee is going to coordinate with NRC Region 4 and State of Louisiana personnel to identify a source/tool recovery team to search for the radioactive source. There is a slight possibility that the tool could be caught on the platform substructure that is normally inaccessible by personnel.

HIGH PRESSURE COOLANT INJECTION (HPCI) INOPERABLE DUE TO CONTROLLER SIGNAL CONVERTER TROUBLE.

"On October 19, 2004 at approximately 1830 hours CDT, Unit One was performing QCOS 2300-05, Quarterly HPCI Pump Operability Test. This was being performed to prove operability following maintenance work on various valves and the turning motor gear unit. At this time when the HPCI turbine was rolled, the HPCI Signal Converter Trouble alarm was received. The HPCI Flow Controller demand controlled at approximately 7250 gpm instead of controlling at the desired 5600 gpm. HPCI was determined not to be operable and was shutdown per procedure. Due to the unexpected behavior of the HPCI Flow Controller, at this time it is not certain if the HPCI will meet its safety function. Therefore, we are reporting this event under 10 CFR 50.72 (b)(3)(v)."

Licensee entered Tech Spec 3.5.1.(f) 14 day Limiting Condition of Operation (LCO) for HPCI. Reactor Core Isolation Cooling (RICI) is operable. All other Emergency Core Cooling Systems (ECCS) and the Emergency Diesel Generators (EDG) are fully operable if needed.

The NRC Resident Inspector was notified of this event by the licensee.

* * * RETRACTION J. DAVIS TO W. GOTT AT 1819 ON 10/28/04 * * *

"The purpose of this report is to retract the ENS report made on October 19, 2004 at 2237 CDT (ENS #41139). The initial report was made following HPCI operability testing in accordance with QCOS 2300-05, Quarterly HPCI Pump Operability Test. When the HPCI turbine was rolled, the HPCI Signal Converter Trouble alarm was received. The HPCI Flow Controller failed to control at the desired 5600 gpm (instead, the system ramped to 7250 gpm). Due to the unexpected behavior, it was not certain at the time if HPCI could have met its design basis requirements. However, a subsequent review of this event has determined that HPCI would have performed its safety function. The Signal Converter failed in a manner that prevented automatic flow control, but did not prevent HPCI from initiating and ramping to full flow (i.e., the turbine high speed stop). In this condition, HPCI would have met corresponding Technical Specifications and Accident Analysis requirements. The circuit board was replaced and the Signal Converter and flow controller feedback loop were re-calibrated. The Unit 1 HPCI turbine's automatic flow control was successfully tested on October 20, 2004."

The Licensee notified the NRC Resident Inspector.

Notified R3DO (R. Garner)

STANDBY EMERGENCY ELECTRICAL POWER PATHS INOPERABLE FOR 41 MINUTES

"The Keowee Hydro Units provide the emergency power source for the Oconee Units. At 0357 on 10/19/04, Keowee Unit 1 (and the overhead emergency power path) was declared inoperable in order to perform scheduled maintenance. At 1730, Keowee Unit 2 (and the underground emergency power path) was declared inoperable due to the loss of breaker control power associated with Keowee Unit 2 auxiliaries. At 1811, as required by Technical Specification 3.8.1 condition I, both standby buses were energized from a Lee Combustion Turbine via an isolated power path. At 1828, a Operability Verification of Keowee Unit 2 to the overhead emergency power path was performed with all acceptance criteria met. At 1904, Keowee Unit 2 to the overhead emergency power path was declared operable. Technical Specification 3.8.1 condition I was exited.

"Initial Safety Significance: Between times 1730 to 1811, both on site emergency power paths were inoperable. During this time period a condition existed that could have prevented the fulfillment of the safety function of systems that are needed to mitigate the consequences of an accident.

"Corrective Action(s): At 1828, an Operability Verification of Keowee Unit 2 to the overhead emergency power path was performed with all acceptance criteria met. At 1904, Keowee Unit 2 to the overhead emergency power path was declared operable. Technical Specification 3.8.1. condition I was exited. A team is established to investigate the loss of breaker control power associated with Keowee Unit 2 auxiliaries."

The licensee will notify the NRC Resident Inspector.

* * * RETRACTION FROM TODD TO HUFFMAN AT 1428 EDT ON 10/26/04 * * *

"The Keowee Hydro Units (KHUs) provide the emergency power source for the three Oconee Units. On 10/20/04 at 0135 Oconee made a notification to the NRC of a loss of safety function. Reference Event Number: 41140. The event was due to an unexpected failure on KHU 2. At the time of the event, KHU 1 was out of service for planned maintenance and was in the early stages of testing for return to service.

"Each KHU can be aligned to either an overhead or an underground power path to supply emergency power to Oconee. At 1730, KHU 2 and the underground emergency power path were declared inoperable due to the loss of breaker control power associated with KHU 2 auxiliaries while aligned to the underground path. By the Oconee Technical Specification 3.8.1 Bases, this breaker (ACB-8) is required to be operable in order to consider KHU 2 operable while aligned to the underground path. Since KHU 2 did not meet the TS configuration, and since KHU 1 testing was not complete, both trains were inoperable and the event was reported as a loss of safety function. At 1811, as required by Technical Specification 3.8.1 condition I, both standby buses were energized from a Lee Combustion Turbine via a dedicated power path. KHU 2 was re-aligned to the overhead path and its associated auxiliary power breaker (ACB-6). The event was terminated at 1904 when KHU 2 was declared operable to the overhead emergency power path after completion of an Operability Verification test.

"Justification for conclusion that there was no loss of safely function while KHU 2 was declared inoperable (approximately one hour duration):

"KHUs are capable of 'black start', i.e. starting and operating on battery power alone. Therefore, if there had been an event resulting in an emergency start signal during the one hour interval of vulnerability, KHU 2 would have been able to start and operate for approximately one hour with the loss of control power to ACB-8. Operations procedures include guidance to close breaker ACB-8 manually using a maintenance closure handle. These steps would have been performed approximately 30 minutes into the postulated event. Based on the results of testing and troubleshooting of ACB-8, Oconee has concluded that ACB-8 could have been closed manually and, once closed, would have successfully provided auxiliary power for the duration of any event.

"Thus Oconee concludes that KHU 2 should be considered available, with reasonable expectation for performing its safety function during this event. Therefore Oconee has concluded that this event was not a reportable loss of safety function and Event Number 41140 is withdrawn."

The resident inspector and R2DO (Bonser) have been notified.

AGREEMENT STATE REPORT - THREE WELL LOGGING SOURCES ABANDONED DOWNHOLE

"Well: Mako Steward A-37 State Tract #1, Galveston, County, Texas
9,150 ft. downhole (bottom of well)

"Well logging string became stuck in a 6 3/4" wellbore over the weekend. Attempts to 'fish' for the sources was unsuccessful with the fishing tool becoming stuck in the wellbore above the well logging tool string. The tool string contains three sealed sources: an 18 curie Am-241/Be; a 2 curie Cs-137; and a 0.8 microcurie Cs137. The sources were declared abandoned late on October 19, 2004. The Licensee is preparing to seal the well with red dyed cement and placement of a deflection device in the wellbore. The tool string is sitting at the bottom of the well at 9,150 feet downhole. Source manufacturers and serial numbers are currently unavailable."

Texas Incident No. I-8175

LOSS OF NORMAL POWER SUPPLY TO "2E" SWITCHGEAR RESULTED IN AFW AUTOSTART

"Unit 2 experienced an autostart of Auxiliary Feedwater System (AFW) and Emergency Diesel Generator 'B' following transfer of the '2E' Switchgear to Alternate Power Supply.

"Normal Power Supply (XST1) experienced a loss of power, causing the '2E' Switchgear to slow transfer to the -2 Breakers from the Alternate Power Supply (XST2).

"The AFW (MDAFWP [Motor-driven Auxiliary Feedwater Pumps] 'A' and 'B' and TDAFWP [Turbine-driven Auxiliary Feedwater Pump]) autostarted due to Sequencer Operations.

"The EDG 'B' autostarted on low voltage condition but did not supply power to the affected '2E' bus. The EDG 'B' cooling water was provided by the service water system.

"Power was restored to XST1 at 0606 CDT. The cause of the EDG 'B' autostart is under investigation. The cause of the loss of power to XST1 is under investigation. Power was reduced to 98.2% to ensure Nuclear Power <100%. All other systems functioned as required. Local NRC Resident was informed."