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This 60-day telephone notification is bein … This 60-day telephone notification is being made in accordance with the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system.</br>On September 13, 2012, Browns Ferry Nuclear Plant (BFN) personnel completed the installation of three metal-oxide varistors (MOVs), MOV1, MOV2, and MOV3, on the governor of the 3C Emergency Diesel Generator (EDG) as part of a design change. On September 17, 2012, at 0312 hours Central Daylight Time (CDT), during post-modification testing of the 3C EDG, the Direct Current (DC) control circuit breaker tripped, causing a loss of governor control power for the 3C EDG. This event resulted in the loss of the 3B Reactor Protection System (RPS) Bus. In addition, Primary Containment Isolation System (PCIS) groups 3, 6, and 8 successfully isolated. The Steam Vault Booster Fan tripped and the 3B Steam Jet Air Ejector isolated. Standby Gas Treatment (SGT) Trains 'A' and 'B' and Control Room Emergency Ventilation Train 'A' initiated. The SGT Train 'C' was already in service for BFN, Unit 3, Reactor Zone Ventilation.</br>Plant Conditions which initiate PCIS Group 3 actuations are Reactor Vessel Low Water Level or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level, High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid.</br>The affected equipment responded as designed. On September 17, 2012, at 0335 hours CDT, Operations personnel restored the 3B RPS Bus.</br>This condition was the result of MOV1 and MOV3 operating due to induced current in their associated ground cables. This resulted in grounds which tripped the DC control power breaker. To address this condition, MOV1 and MOV3 were permanently removed.</br>There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the Corrective Action Program as Problem Evaluation Report 610091.</br>The NRC Resident Inspector has been notified of this event.Inspector has been notified of this event.
09:12:00, 17 September 2012 +
15:34:00, 14 November 2012 +
09:12:00, 17 September 2012 +
This 60-day telephone notification is bein … This 60-day telephone notification is being made in accordance with the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system.</br>On September 13, 2012, Browns Ferry Nuclear Plant (BFN) personnel completed the installation of three metal-oxide varistors (MOVs), MOV1, MOV2, and MOV3, on the governor of the 3C Emergency Diesel Generator (EDG) as part of a design change. On September 17, 2012, at 0312 hours Central Daylight Time (CDT), during post-modification testing of the 3C EDG, the Direct Current (DC) control circuit breaker tripped, causing a loss of governor control power for the 3C EDG. This event resulted in the loss of the 3B Reactor Protection System (RPS) Bus. In addition, Primary Containment Isolation System (PCIS) groups 3, 6, and 8 successfully isolated. The Steam Vault Booster Fan tripped and the 3B Steam Jet Air Ejector isolated. Standby Gas Treatment (SGT) Trains 'A' and 'B' and Control Room Emergency Ventilation Train 'A' initiated. The SGT Train 'C' was already in service for BFN, Unit 3, Reactor Zone Ventilation.</br>Plant Conditions which initiate PCIS Group 3 actuations are Reactor Vessel Low Water Level or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level, High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid.</br>The affected equipment responded as designed. On September 17, 2012, at 0335 hours CDT, Operations personnel restored the 3B RPS Bus.</br>This condition was the result of MOV1 and MOV3 operating due to induced current in their associated ground cables. This resulted in grounds which tripped the DC control power breaker. To address this condition, MOV1 and MOV3 were permanently removed.</br>There were no safety consequences or impact to the health and safety of the public as a result of this event. This event was entered into the Corrective Action Program as Problem Evaluation Report 610091.</br>The NRC Resident Inspector has been notified of this event.Inspector has been notified of this event.
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00:00:00, 14 November 2012 +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
02:02:29, 2 March 2018 +
15:34:00, 14 November 2012 +
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58.224 d (1,397.37 hours, 8.318 weeks, 1.914 months) +
09:12:00, 17 September 2012 +
60-Day Optional Telephonic Notification of Invalid Actuation of Containment Isolation Signals +
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