ENS 48570
ENS Event | |
|---|---|
14:12 Oct 12, 2012 | |
| Title | Temperature Switch Failure Causes Division I Isolation Signal |
| Event Description | 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. |
| Where | |
|---|---|
Nine Mile Point  New York (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1343.62 h55.984 days <br />7.998 weeks <br />1.84 months <br />) | |
| Opened: | Anthony Petrelli 14:49 Dec 7, 2012 |
| NRC Officer: | Pete Snyder |
| Last Updated: | Dec 7, 2012 |
| 48570 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 535842018-03-19T04:00:00019 March 2018 04:00:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation ENS 527472017-03-20T06:16:00020 March 2017 06:16:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Telephone Notification for an Invalid High Pressure Coolant Injection System Actuation ENS 509092015-01-21T15:00:00021 January 2015 15:00:00 10 CFR 50.73(a)(1), Submit an LER 60-Day Optional Notification - Invalid Containment Isolation Signal ENS 490842013-04-02T13:46:0002 April 2013 13:46:00 10 CFR 50.73(a)(1), Submit an LER 6O-Day Optional Telephone Notification for an Invalid Specified System Actuation ENS 485702012-10-12T14:12:00012 October 2012 14:12:00 10 CFR 50.73(a)(1), Submit an LER Temperature Switch Failure Causes Division I Isolation Signal ENS 481132012-05-24T14:20:00024 May 2012 14:20:00 10 CFR 50.73(a)(1), Submit an LER 60 - Day Optional Telephone Notification of an Invalid Division 2 Containment Isolation Signal ENS 475472011-11-08T03:31:0008 November 2011 03:31:00 10 CFR 50.73(a)(1), Submit an LER Invalid Specified System Actuation Due to a Possible Faulty Temperature Switch ENS 457792010-03-15T16:43:00015 March 2010 16:43:00 10 CFR 50.73(a)(1), Submit an LER Inadvertent Start of Emergency Diesel Generator ENS 439232008-01-14T18:41:00014 January 2008 18:41:00 10 CFR 50.73(a)(1), Submit an LER Invalid Actuation of Group 5 and Group 10 Primary Containment Valves During Surveillance Testing ENS 438552007-11-08T15:21:0008 November 2007 15:21:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System (Pcis) Actuation ENS 407182004-04-01T07:06:0001 April 2004 07:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Automatic Start of Emergency Diesel Generator During Surveillance Test 2018-03-19T04:00:00 | |