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| Entered date | Event description | |
|---|---|---|
| ENS 48570 | 7 December 2012 14:49:00 | This 60-day telephone notification is being made per the reporting requirements specified in 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation signal affecting containment isolation valves in more than one system. On October 12, 2012, Nine Mile Point Unit 2 (NMP2) received a Division I primary containment isolation signal which resulted in the closure of Group 5, 6, and 10 primary containment isolation valves (PCIVs) in the following systems: Group 5 PCIVs: Residual Heat Removal System (RHS); Shutdown Cooling (SDC); Group 6 PCIVs: Reactor Water Cleanup System (WCS) supply outside isolation valve; and Group 10 PCIVs: Reactor Core Isolation Cooling (RCIC) System. All affected PCIVs responded as designed. The Division I isolation signal was generated due to the failure of a temperature switch unit. The Division I and II temperature switch units were both reading within limits when the Division I unit failed. Since the isolation signal was not initiated in response to actual plant conditions or parameters satisfying the requirements for initiation, the isolation signal was determined to be invalid. The event was entered into the corrective action program as Condition Report CR-2012-009380. There were no safety consequences and no impact to the health and safety of the public as a result of this event. The licensee notified the New York State Public Service Commission and the NRC Resident Inspector. |
| ENS 46385 | 1 November 2010 23:30:00 | During the performance of rounds an operator found a leak on the traveling water screens. The traveling water screens are part of the Service Water System. The travelling screen drive chain oil reservoir was found empty. It is estimated that approximately 5 gallons of oil entered the Service Water System forebay. The oil residue has been cleaned up. The environmental impact will be assessed following further investigation. Notifications have been made to NYSDEC (New York State Department of Environmental Conservation) and National Response Center. NYS (New York State) spill #: 1008090 National Response Center spill #: 958672. The licensee will notify the NRC Resident Inspector. |
| ENS 43923 | 22 January 2008 20:16:00 | This is not an LER. The reports being made to the NRC under 10 CFR 50.73(a)(2)(iv)(A), and the 60 day telephone notification option under 10 CFR 50.73(a)(1). The event included invalid '. . .general isolation signals affecting containment isolation valves in more than one system. . .' as discussed in 10 CFR 50.73(a)(2)(iv)(B). The following information is provided as requested in NUREG-1022: (a) The specific train(s) and systems that were actuated? On January 14, 2008 at 13:41 hours. Unit 2 received invalid Division 1 Primary Containment isolation signals to both Group 5 (RHR Shutdown Cooling Isolation valves) and Group 10 (Reactor Core Isolation Cooling (RCIC) system isolation valves) during Division 1 instrumentation surveillance testing. While performing testing, an incorrect lead was lifted causing this invalid actuation. (b) Whether each train actuation was complete or partial. The event resulted in closure of the RCIC steam supply header outboard containment isolation valve. The Division 1 RHR Shutdown Cooling System isolation valves were already closed at the time of the isolation signal. (b) Whether or not the system started and functioned as designed. The Primary Containment isolation instrumentation logic and associated valve closure function (for RCIC) actuated as designed. The licensee took prompt actions to recover the RCIC and RHR systems. The licensee notified the NRC Resident Inspector. |
| ENS 43855 | 20 December 2007 13:35:00 | This 60-day telephone notification is being made under reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of the containment isolation signals affecting more than one system. On November 8, 2007, at 1021 hours, with Unit 2 shutdown for a planned mid-cycle outage to remove a defective fuel bundle and conduct other maintenance activities, two primary containment isolation valves in different systems closed unexpectedly. The valves closed during application of a clearance section that inadvertently created a false primary containment isolation signal. None of the plant conditions which require PCIS Group 5 or 7 actuation (low reactor water level, high reactor pressure, high area temperature, etc.) existed; therefore, these actuations are considered invalid. The following two primary containment isolation valve isolations/actuations occurred: - Residual Heat Removal shutdown cooling supply inside isolation valve (2RHS*MOV112, Group 5) - Reactor Water Cleanup supply from Reactor Coolant System and Reactor Pressure Vessel inside isolation valve (2WCS*MOV102, Group 7) The valves functioned successfully as they cycled completely from full open to full closed. The event was entered into NMP's corrective action program for evaluation and resolution. The NRC Senior Resident Inspector has been notified of this report. Reference corrective action document CR 2007-6769. |
| ENS 42403 | 10 March 2006 00:58:00 | This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B) RPS Actuation (scram) for Nine Mile Point Unit 2 which states 'Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' On 03/09/2006 at 2214 while operating at approximately 85 % reactor power (coast down to refueling) a condenser low vacuum condition resulted in a turbine trip and a subsequent reactor scram. A loss of sealing steam most probably caused the loss of condenser vacuum and an investigation is in progress. Special Operating procedure N2-SOP-101 C was entered. All control rods inserted (fully) as expected. Condenser vacuum has been stabilized and the main steam isolation valves are open. The plant is stable and recovery actions are in progress. Decay heat is being removed via the turbine bypass valves to the main condenser. The condensate and feedwater system is in operation maintaining reactor vessel level. The electric plant is in a normal shutdown lineup and there was no effect from this transient on Unit 1. The licensee notified the NRC Resident Inspector.
This update is being made to provide additional information to EN# 42403 which was communicated via ENS on 3/10/06 at 0058 hours. During the scram that occurred at Nine Mile Point Unit 2 on 3/9/06 at 2214 hours, a primary containment isolation signal to RHR Shutdown Cooling, RHR Head Spray and RHR sample valves was received as designed. No components repositioned as the valves are normally closed during plant operations. The licensee will notify the NRC Resident Inspector. Notified R1DO (P. Krohn). |