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| Entered date | Event description | |
|---|---|---|
| ENS 48453 | 29 October 2012 21:58:00 | On October 29, 2012 at 2100 EDT, Nine Mile Point Unit 1 experienced an automatic reactor scram due to a generator load reject. The cause of the load reject is currently under investigation. All control rods fully inserted and all plant systems responded per design following the scram. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated as expected. At Nine Mile Point Unit 1, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. HPCI is a flow control mode of the normal feedwater systems, and is not an Emergency Core Cooling System. At 2101 EDT, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was established on the Turbine Bypass Valves, the preferred system. Three Electromatic Relief Valves actuated due to this scram and re-closed automatically. Nine Mile Point Unit 1 is currently in Hot Shutdown, with reactor water level and pressure maintained within normal bands. Decay heat is being removed via steam to the main condenser using bypass valves. Both Reserve Station Transformers are in service and being supplied by their normal power sources. Both Emergency Diesel Generators are operable and in standby. The unit is currently implementing post scram recovery procedures. The licensee has notified the NRC Resident Inspector. Notified R1DO (Caruso). |
| ENS 47910 | 8 May 2012 19:09:00 | On 5/8/2012 at 1114 EDT, maintenance informed the Control Room that a fan blade on one of the Technical Support Center (TSC) ventilation compressors had failed, causing the fan and motor to become unstable. As a result, Operations secured TSC ventilation and declared the TSC non-functional. The on-call Emergency Response Manager and Site Emergency Coordinator were notified and the alternate TSC remains available. The affected unit has been isolated and TSC ventilation re-started and declared functional as of 1900 EDT on 5/8/2012. The license will notify the NRC Resident Inspector. |
| ENS 47331 | 7 October 2011 20:55:00 | On 10/07/11, at approximately 1320 EDT, Nine Mile Point Unit 1 received multiple annunciators related to the offsite power tone monitoring system. These annunciators were subsequently determined to have been caused by damage to an offsite fiber optic cable line. The damaged fiber optic cable also disabled the Emergency Notification System (ENS) and Radiological Emergency Communication System (RECS) communication lines, which is reportable under 10 CFR 50.72(3)(b)(xiii). ENS is the Control Room's primary method for communicating with the NRC headquarters during emergency conditions. If an emergency is declared with the ENS line inoperable, the Control Room maintains the ability to make notification to offsite agencies using commercial telephone lines. Control Room personnel have been briefed on the required contingent actions with the ENS line inoperable. The licensee notified the NRC Resident Inspector and State and local agencies. See related event notification EN #47332. |