ENS 47061
ENS Event | |
|---|---|
20:55 Jul 14, 2011 | |
| Title | Inoperable Criticality Accident Alarm System Warning Horns |
| Event Description | As part of the corrective actions for the event reported on 7/13/11 [EN #47047], GNF-A performed a Criticality Accident Alarm System (CAAS) audibility test covering the Controlled Access Area (CAA) at approximately 1655 on 7/14/11. The subsequent test revealed that the installed CAAS system failed to immediately activate the horn signal generators as expected. Activation of the associated warning horns was delayed approximately 3 minutes. This response time to activate horns did not meet the design requirement. Additionally, a review determined an approximately 3 minute horn signal delay was noted in a previous test on 7/12/11. An investigation into these matters is ongoing.
The FMO [Fuel Manufacturing Operations] complex fissile material process operations were suspended on 7/14/11 and personnel evacuated. The emergency organization was activated and efforts to troubleshoot the root cause in the horn signal activation circuit delay initiated. All production activities involving Special Nuclear Material are shut down. The installed CAAS is a safety-significant system and is maintained through routine response checks and scheduled functional tests conducted in accordance with internal procedures. These events are being reported pursuant to the requirements of 10CFR70.50(b)(2). The licensee notified NRC Region 2 personnel (Sykes), State of North Carolina Radiation Protection, and New Hanover County EMA.
The cause of the inoperable Criticality Accident Alarm System (CAAS) has been identified as a hardware failure - specifically a capacitor on a circuit board. The CAAS has been repaired and a comprehensive testing plan is under development. The licensee continues to withhold personnel from the Controlled Access Area and all production activities remain shut down. A root cause analysis and recovery plan are underway. The licensee has contacted R2 (Sykes) and will be notifying state and local authorities. R2DO (Freeman notified). See related Events #47047 and #47066. |
| Where | |
|---|---|
| Global Nuclear Fuel - Americas Wilmington, North Carolina (NRC Region 2) | |
| License number: | SNM-1097 |
| Reporting | |
| 10 CFR 70.50(b)(2) | |
| Time - Person (Reporting Time:+19.33 h0.805 days <br />0.115 weeks <br />0.0265 months <br />) | |
| Opened: | Phillip Ollis 16:15 Jul 15, 2011 |
| NRC Officer: | Donald Norwood |
| Last Updated: | Jul 17, 2011 |
| 47061 - 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":[],"imageoverlays":null} | |
Global Nuclear Fuel with 10 CFR 70.50(b)(2) | |
WEEKMONTHYEARENS 497592014-01-22T18:15:00022 January 2014 18:15:00
[Table view]10 CFR 70.50(b)(2) Inoperable Criticality Warning System Local Alarm in Wilmington Field Services Center Building Number 1 ENS 481002012-07-11T21:40:00011 July 2012 21:40:00 10 CFR 70.50(b)(2) Criticality Horns Rendered Inoperable Due to Lightning Strike ENS 478512012-04-18T17:45:00018 April 2012 17:45:00 10 CFR 70.50(b)(2) Local Alarm Horn Was Found to Be Inaudible During Routine Testing ENS 477242012-03-07T18:15:0007 March 2012 18:15:00 10 CFR 70.50(b)(2) Local Alarm Horn Was Found to Be Inaudible During Routine Testing ENS 472202011-08-29T17:00:00029 August 2011 17:00:00 10 CFR 70.50(b)(2) Criticality Accident Alarm System Horn Discovered Inoperable ENS 470612011-07-14T20:55:00014 July 2011 20:55:00 10 CFR 70.50(b)(2) Inoperable Criticality Accident Alarm System Warning Horns ENS 470472011-07-12T21:30:00012 July 2011 21:30:00 10 CFR 70.50(b)(2) Inaudible Criticality Warning Siren ENS 470662011-05-01T16:00:0001 May 2011 16:00:00 10 CFR 70.50(b)(2) Previous Inoperability of Criticality Accident Alarm System Warning Circuit Not Identified ENS 447242008-12-16T11:00:00016 December 2008 11:00:00 10 CFR 70.50(b)(2) Criticality Warning System Disabled ENS 432672007-03-30T11:40:00030 March 2007 11:40:00 10 CFR 70.50(b)(2) Criticality Warning System Alarm Actuation Due to Power Fluctuation ENS 429792006-11-09T10:00:0009 November 2006 10:00:00 10 CFR 70.50(b)(2) Failure of Warning Horns ENS 427472006-08-01T09:00:0001 August 2006 09:00:00 10 CFR 70.50(b)(2) Audible Horn System Malfunction ENS 406332004-04-01T18:00:0001 April 2004 18:00:00 10 CFR 70.50(b)(2) Outdoor Area Criticality Warning System Horn Inoperative 2014-01-22T18:15:00 | |