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At 0400 hours on January 12, 2006, 2A ContAt 0400 hours on January 12, 2006, 2A Control Building Standby Instrument Air Compressor was taken out of service for scheduled maintenance. Subsequently, at 0920 hours, the in-service 2B Control Building Standby Instrument Air Compressor failed, resulting in the loss of control air. As a result, the three Control Room Air Conditioning subsystems required by Technical Specification (TS) 3.7.4, "Control Room Air Conditioning (AC) System," and the two Control Room Emergency Ventilation subsystems required by TS 3.7.3, "Control Room Emergency Ventilation (CREV) System," became inoperable. As a result, this condition could have prevented the fulfillment of the safety function for these systems. The Control Room AC and CREV systems became inoperable due to loss of control air to the systems. Because Brunswick has a shared control room, Unit 1 and Unit 2 entered TS 3.7.3 Required Action B.1, for two CREV subsystems inoperable (i.e., be in Mode 3 within 12 hours) and TS 3.7.4, Required Action E.1, for three Control Room AC subsystems inoperable (i.e., enter LCO 3.0.3 immediately). </br>Operability of two Control Room AC subsystems and one CREV subsystem was restored and LCO 3.0.3 was exited, at 1014 hours, when the 2A Control Building Standby Instrument Air Compressor was restored to service. (The licensee stated the actual maintenance was completed on 2A Control Building Standby Instrument Air Compressor at the time it was restored to service.)</br>No power reduction took place as a result of the LCO 3.0.3 entry. This report applies to both Units 1 and 2 and is being made in accordance with 10 CFR 50.72(b)(3)(v)(D), as a condition that at the time of discovery could have prevented fulfillment of the safety function of systems that are needed to mitigate the consequences of an accident.</br>The safety significance of this event is considered minimal. The condition existed for approximately 54 minutes. Plant staff took immediate actions to return the equipment to service. For the brief time the Control Room AC and CREV systems were inoperable, performance of plant personnel and equipment in the Control Room was not adversely affected. The maximum Control Room back panel temperature during this event was approximately 73 degrees F.</br>Operability of the Control Room AC system and one subsystem of the CREV system were restored at 1014 hours when the 2A Control Building Standby Instrument Air Compressor was restored to service. Troubleshooting activities are under way to determine the cause of the 2B Control Building Standby Instrument Air Compressor failure. Initial indications are that the unloading ability of the 2B Control Building Standby Instrument Air Compressor failed.</br>The licensee notified the NRC Resident Inspector.ensee notified the NRC Resident Inspector.  
14:20:00, 12 January 2006  +
42,254  +
16:07:00, 12 January 2006  +
14:20:00, 12 January 2006  +
At 0400 hours on January 12, 2006, 2A ContAt 0400 hours on January 12, 2006, 2A Control Building Standby Instrument Air Compressor was taken out of service for scheduled maintenance. Subsequently, at 0920 hours, the in-service 2B Control Building Standby Instrument Air Compressor failed, resulting in the loss of control air. As a result, the three Control Room Air Conditioning subsystems required by Technical Specification (TS) 3.7.4, "Control Room Air Conditioning (AC) System," and the two Control Room Emergency Ventilation subsystems required by TS 3.7.3, "Control Room Emergency Ventilation (CREV) System," became inoperable. As a result, this condition could have prevented the fulfillment of the safety function for these systems. The Control Room AC and CREV systems became inoperable due to loss of control air to the systems. Because Brunswick has a shared control room, Unit 1 and Unit 2 entered TS 3.7.3 Required Action B.1, for two CREV subsystems inoperable (i.e., be in Mode 3 within 12 hours) and TS 3.7.4, Required Action E.1, for three Control Room AC subsystems inoperable (i.e., enter LCO 3.0.3 immediately). </br>Operability of two Control Room AC subsystems and one CREV subsystem was restored and LCO 3.0.3 was exited, at 1014 hours, when the 2A Control Building Standby Instrument Air Compressor was restored to service. (The licensee stated the actual maintenance was completed on 2A Control Building Standby Instrument Air Compressor at the time it was restored to service.)</br>No power reduction took place as a result of the LCO 3.0.3 entry. This report applies to both Units 1 and 2 and is being made in accordance with 10 CFR 50.72(b)(3)(v)(D), as a condition that at the time of discovery could have prevented fulfillment of the safety function of systems that are needed to mitigate the consequences of an accident.</br>The safety significance of this event is considered minimal. The condition existed for approximately 54 minutes. Plant staff took immediate actions to return the equipment to service. For the brief time the Control Room AC and CREV systems were inoperable, performance of plant personnel and equipment in the Control Room was not adversely affected. The maximum Control Room back panel temperature during this event was approximately 73 degrees F.</br>Operability of the Control Room AC system and one subsystem of the CREV system were restored at 1014 hours when the 2A Control Building Standby Instrument Air Compressor was restored to service. Troubleshooting activities are under way to determine the cause of the 2B Control Building Standby Instrument Air Compressor failure. Initial indications are that the unloading ability of the 2B Control Building Standby Instrument Air Compressor failed.</br>The licensee notified the NRC Resident Inspector.ensee notified the NRC Resident Inspector.  
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