ENS 41755
ENS Event | |
|---|---|
00:20 Jun 8, 2005 | |
| Title | Twenty-Eight Early Warning Sirens Temporarily Inoperable |
| Event Description | On June 7th 2005 at 20:00 hours our EWSS System performed an automated poll of active Early Warning Sirens. Normally this action is completed in 15 to 20 minutes. This polling indicated not all sirens had responded to the automated signal. Emergency planning department personnel were notified and called to site to determine system status. Their attempts to manually poll the active sirens determined that twenty eight (28) sirens were not responding. Our EWSS system consists of one hundred six (106) sirens. A loss of twenty eight (28) sirens left our system at seventy three percent (73%) of its capacity. South Carolina state and the four (4) local counties were notified of the systems condition within one hour as required by our Nuclear Licensing procedure (NL-122). This same procedure requires an eight (8) hour telephone notification to the Nuclear Regulatory Commission. This requirement is based on 10CFR50.72(b)(3)(xiii).
At 00:15 hours June 8th 2005 our communications department located the faulty siren and disabled its radio transponder, this action restored the other twenty seven (27) sirens to service. This restoration was verified by performing a manual poll of active sirens. The South Carolina state and local counties were notified of system restoration. During the evening hours of June 7th 2005 a thunder storm passed through the station's ten (10) mile emergency planning zone. One siren, Fairfield fifty two (F-52) had apparently been struck by lightning and caused its radio transponder to go into a continuous transmit mode. This errant radio signal blocked the polling signal from the other twenty seven (27) sirens. Based on communications department report had the EWSS system been actuated those twenty eight (28) sirens would not have sounded as required. The licensee has notified State and local authorities as well as the NRC Resident Inspector.
On June 7th 2005 at 20:00 hours our EWSS System performed an automated poll of active Early Warning Sirens. Normally this action is completed in 15 to 20 minutes. This polling indicated not all sirens had responded to the automated signal. Emergency planning department personnel were notified and called to site to determine system status. Their attempts to manually poll the active sirens determined that twenty eight (28) sirens were not responding. Our EWSS system consists of one hundred six (106) sirens. A loss of twenty eight (28) sirens left our system at seventy three percent (73%) of its capacity. South Carolina state and the four (4) local counties were notified of the systems condition within one hour as required by our Nuclear Licensing procedure (NL-122). This same procedure requires an eight (8) hour telephone notification to the Nuclear Regulatory Commission. This requirement is based on 10CFR50.72(b)(3)(xiii). At 00:15 hours June 8th 2005 our communications department located the faulty siren and disabled its radio transponder, this action restored the other twenty seven (27) sirens to service. This restoration was verified by performing a manual poll of active sirens. The South Carolina state and local counties were notified of system restoration. During the evening hours of June 7th 2005 a thunder storm passed through the station's ten (10) mile emergency planning zone. One siren, Fairfield fifty two (F-52) had apparently been struck by lightning and caused its radio transponder to go into a continuous transmit mode. This errant radio signal blocked the polling signal from the other twenty seven (27) sirens. Based on the licensee's Communications Department Report, if the EWSS had been actuated, all sirens, except the faulty siren struck by lightning would have activated. However, the siren feedback system may not have been able to determine if all sirens activated. The licensee notified the NRC Resident Inspector. Notified R2DO (Munday) |
| Where | |
|---|---|
Summer  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | |
| Time - Person (Reporting Time:+2.47 h0.103 days <br />0.0147 weeks <br />0.00338 months <br />) | |
| Opened: | Steven Webster 02:48 Jun 8, 2005 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Dec 22, 2006 |
| 41755 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 572782024-08-21T00:01:00021 August 2024 00:01:00
[Table view]10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Control Room Ventilation Inoperable ENS 527052017-04-25T13:00:00025 April 2017 13:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Fuel Handling Bridge Radiation Monitor Out of Service ENS 485182012-11-18T16:30:00018 November 2012 16:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Assessment Capability Due to Integrated Plant Computer Planned Maintenance ENS 429912006-11-14T21:42:00014 November 2006 21:42:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Emergency Siren Activation Capability Inoperable for Approximately 15 Minutes ENS 425602006-05-08T16:30:0008 May 2006 16:30:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Early Warning Siren System (Ewss) Declared Inoperable ENS 417552005-06-08T00:20:0008 June 2005 00:20:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Twenty-Eight Early Warning Sirens Temporarily Inoperable ENS 413632005-01-30T09:10:00030 January 2005 09:10:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Siren Capability Due to Adverse Weather ENS 412422004-12-04T03:30:0004 December 2004 03:30:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Early Warning Siren System Failure ENS 411142004-10-11T14:57:00011 October 2004 14:57:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Emergency Siren Capability Following Planned Siren Maintenance ENS 404832004-01-27T17:00:00027 January 2004 17:00:00 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness Loss of Ens Telephone and Siren System 2024-08-21T00:01:00 | |