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| Entered date | Event description | |
|---|---|---|
| ENS 40506 | 5 February 2004 15:45:00 | During performance of a weekly preventive maintenance activity, (it was) discovered that the discharge dampers of Emergency Diesel Generator 102 Exhaust Fans opened approximately one inch vice full open as expected. Technical Specification 3.6.3e 14 day shutdown LCO was entered at 13:40. At 1350, Technical Specification 3.6.3e(1) was entered due to as found condition of both ventilation exhaust dampers for Emergency Diesel Generators 102 and 103 covered with snow and ice preventing normal operation of dampers. This condition required an initiation of normal orderly shutdown in one hour and the Reactor in cold shutdown condition within ten hours. At 14:10, Emergency Diesel Generators 102 and 103 were declared operable based on snow/ice removal and satisfactory completion of testing on all fans and dampers. The Licensee notified the NRC Resident Inspector.
This Event Notification is being made to rescind previous Event Notification made on 2/05/2004. The notification was made as an eight hour report per 10 CFR50.72 (b)(3)(v)(D) and an LER IAW 10CFR50.73(a)(2)(v)(D) and (vi). Subsequent Engineering evaluation has concluded that the Emergency Diesel Generators (EDGs), and more specifically their Room Ventilation Fans (Support System) would have performed their design function. The specific event described a snow and ice condition that impeded the Ventilation Fan Dampers from fully opening. The dampers did however, partially open. Engineering has concluded that although there was reduced ventilation flow through the dampers, the air flow rate through the reduced exhaust fan opening would have melted the snow and ice. The melting would have occurred at a progressively faster rate (as the exhaust flow rate and room air temperature both increased) and eventually provided adequate ventilation flow to maintain normal room temperature. Notified R1DO (Todd Jackson). |
| ENS 40322 | 13 November 2003 23:39:00 | Auto initiation of Emergency Diesel Generator (EDG) 103 and re-energizing of PB 103 from EDG due to loss of off-site 115 KV line #4. Line #4 was momentarily lost, then re-energized. The loss of power also resulted in a trip of Reactor Recirculating Pump 13. Power reduced to approximately 80% rated. Recovery operations are in progress. All systems functioned as required and there was not anything unusual or not understood. The NRC Resident Inspector was notified. |
| ENS 40232 | 8 October 2003 13:45:00 | Nine Mile Point Unit 1 entered a Technical Specification (TS) required shutdown due to suspected unsatisfactory allowable leakage past Primary Coolant System Pressure Isolation Valves. At 10:30 EST, The Condition Monitoring group notified the Control Room that leakage past the Core Spray keep-fill check valves 40-22 and 40-23 exceeded the TS allowable leak rate. Preliminarily, leakage was quantified at 1.1 gpm (uncorrected). With these two valves declared inoperable, Technical Specification 3.2.7.1b required an orderly shutdown be initiated within 1 hour and the reactor in cold shutdown condition within 10 hours. The shutdown was initiated at 11:27 (hrs). A surveillance test was performed to quantify leakage rate under test conditions. At 13:10 (hrs), it was determined that the leakage rate was 0.156 gpm (corrected to 1080 psid) and that the previous data received was not valid. The TS required shutdown was suspended and power recovery is planned. The licensee has informed the NRC Resident Inspector. |