ENS 40371
ENS Event | |
|---|---|
05:00 Oct 31, 2003 | |
| Title | Invalid Group Iii Primary Containment Isolation System Actuation |
| Event Description | This notification is being made in accordance with 10CFR50.73(a)(2)(iv)(A) to provide the NRC with information pertaining to the Primary Containment Isolation System (PCIS) Group III invalid actuation signals that affected containment isolation valves in more than one system on two separate occasions.
On October 31, 2003 and November 9, 2003, with the reactor at full power, an invalid actuation of the 'B' Reactor Building Ventilation Monitor caused Group III isolations of PCIS. A spike that was caused by electronic noise within the detector invoked a spurious High Level Trip to this monitor (RM 17-452B), that resulted in a trip to PCIS logic Channel B1. The PCIS functioned successfully providing a complete Group III isolation. The train actuation was complete. Both trains of the Standby Gas Treatment System started as designed. The PCIS Group III isolation occurred which involves isolation of valves in the following systems: Drywell Air Purge and Vent, Drywell and Suppression Chamber Main Exhaust, Suppression Chamber Purge and Vent, Containment Air Compressor Suction Valve, Exhaust to Standby Gas Treatment, Containment Purge Supply and Makeup, Containment Air Sampling, Air dilution Subsystem Valves, Vent Subsystem Valves, and Containment Air Dilution Vent System MOV VG-22 A/B. It was determined that both of these Group III isolations were invalid, due to the Reactor Building Vent Monitor Radiation Level Trip occurring at 25 millirem/hr on 10/31/03 and 15 millirem/hr on 11/09/03. General area radiation levels in these areas at the time of the event were approximately 2.5 millirem/hr to 6 millirem/hr. The licensee will notify the NRC Resident Inspector. |
| Where | |
|---|---|
| Vermont Yankee File:NorthStar Vermont Yankee icon.png Vermont (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+801.63 h33.401 days <br />4.772 weeks <br />1.098 months <br />) | |
| Opened: | Kelly Robinson 14:38 Dec 3, 2003 |
| NRC Officer: | Jeff Rotton |
| Last Updated: | Dec 3, 2003 |
| 40371 - NRC Website
Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 40371\u003C/a\u003E - \u003Ca href=\"/Vermont_Yankee\" title=\"Vermont Yankee\"\u003EVermont Yankee\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EInvalid Group Iii Primary Containment Isolation System Actuation\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 40371 - Vermont Yankee\n","link":"","lat":42.77900833333333,"lon":-72.51328611111111,"icon":"NorthStar Vermont Yankee icon.png"}],"imageoverlays":null} | |
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 | |