ENS 45009
ENS Event | |
|---|---|
17:26 Mar 24, 2009 | |
| Title | Primary Containment Isolation System (Pcis) Group 3 Invalid Actuation |
| Event Description | This sixty day notification is being made in accordance with 10 CFR 50.73(a)(2)(iv)(A) to provide the NRC with information pertaining to an unplanned invalid actuation of specific systems, specifically, a Primary Containment Isolation System (PCIS) Group 3 actuation signal that affected containment isolation valves in more than one system.
On March 24, 2009, at approximately 1326 hours0.0153 days <br />0.368 hours <br />0.00219 weeks <br />5.04543e-4 months <br />, Vermont Yankee Nuclear Power Station (VYNPS) experienced an invalid PCIS Group 3 isolation associated with personnel error during quarterly calibration of the Refuel Floor Zone Radiation Monitors. VYNPS had removed the East Refuel Floor Zone Radiation Monitor from service for calibration. The technician, in the field, had completed a phone communication with the control room and was dispatched to the East Refuel Floor Zone Radiation Monitor to perform the calibration activity. However, the technician incorrectly went to the inservice West Refuel Floor Zone Radiation Monitor and removed the detector from service. This incorrect action caused a momentary invalid high radiation signal containment isolation signal and the Subsequent PCIS Group 3 isolation. The following actuations resulted: Both trains of the Standby Gas Treatment System started as designed. The PCIS functioned properly providing a complete Group 3 isolation valves in the following system actuated as a result of the PCIS Group 3 isolation: Drywell Air Purge and Vent, Drywell and Suppression Chamber Main Exhaust, Suppression Chamber Purge and Vent, Containment Air Compressor Suction, Exhaust to Standby Gas Treatment, Containment Purge Supply and Makeup, Containment Air Sampling, Air Dilution Subsystem, [and] Containment Air Dilution Vent System. This event has been entered into VYNPS's corrective action program. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Vermont Yankee  Vermont (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+692.18 h28.841 days <br />4.12 weeks <br />0.948 months <br />) | |
| Opened: | Dennis May 13:37 Apr 22, 2009 |
| NRC Officer: | Karl Diederich |
| Last Updated: | Apr 22, 2009 |
| 45009 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 501642014-04-05T11:00:0005 April 2014 11:00:00
[Table view]10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation ENS 498252013-12-15T05:00:00015 December 2013 05:00:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Optional Telephone Notification of Invalid Pcis System Actuation ENS 493582013-07-23T04:00:00023 July 2013 04:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Group 3 Actuation ENS 492112013-06-14T22:06:00014 June 2013 22:06:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation System Actuation Due to a Radiation Monitor Spike ENS 475002011-10-11T21:29:00011 October 2011 21:29:00 10 CFR 50.73(a)(1), Submit an LER Loss of Vital Ac Power While Shutdown ENS 460702010-05-17T04:00:00017 May 2010 04:00:00 10 CFR 50.73(a)(1), Submit an LER 60 Day Report - Invalid Actuation of Hpci and Rcic Systems ENS 450092009-03-24T17:26:00024 March 2009 17:26:00 10 CFR 50.73(a)(1), Submit an LER Primary Containment Isolation System (Pcis) Group 3 Invalid Actuation ENS 437292007-09-15T04:00:00015 September 2007 04:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Primary Containment Isolation ENS 421202005-11-04T21:08:0004 November 2005 21:08:00 10 CFR 50.73(a)(1), Submit an LER Temporary Loss of the Running Rhr Pump During a Bus Transfer ENS 422352005-11-03T00:01:0003 November 2005 00:01:00 10 CFR 50.73(a)(1), Submit an LER Inadvertent Containment Isolation Signal Affecting Containment Isolation Valves ENS 410042004-07-31T17:56:00031 July 2004 17:56:00 10 CFR 50.73(a)(1), Submit an LER Invalid Pcis Actuation ENS 403712003-10-31T05:00:00031 October 2003 05:00:00 10 CFR 50.73(a)(1), Submit an LER Invalid Group Iii Primary Containment Isolation System Actuation 2014-04-05T11:00:00 | |