Browse wiki
Jump to navigation
Jump to search
97 +
On 11/23/2012 at approximately 1956 CST, i … On 11/23/2012 at approximately 1956 CST, it was reported that the Control Room (VC) B Chiller breaker was cycling open and closed. In order to stop the cycling, Control Building Unit Sub B was manually tripped causing the following isolations/actuations: loss of power to instrument air (IA) system containment isolation valves causing the Division 2 valves to isolate; loss of power to the low pressure switch that resulted in an automatic start of Division 2 Shutdown Service Water (SX) system; and loss of power to fuel building (VF) system ventilation Division 2 dampers resulting in a trip of the VF system. High Pressure Core Spray (HPCS) became inoperable based on inoperability of the room cooler for the associated Division 4 inverter and battery charger. Operations entered the Loss of AC Power and Automatic Isolation off-normal procedures. Following the loss of power to the VF system ventilation, at 2008, secondary containment differential pressure became positive. At 2009, power was restored to Control Building Unit Sub B and HPCS was restored to operable. At 2011, the standby gas treatment system (VG) was started and at 2013, secondary containment differential pressure was restored. Following re-energization of Unit Sub B, the IA containment isolation valves were re-opened, VG was secured, VF restarted and the Division 2 SX pump was secured.</br>The loss of secondary containment differential pressure is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material</br>An unplanned inoperability of HPCS reportable under 10 CFR 50.72(b)(3)(v)(D) as HPCS is a single train safety system</br>The cause of the breaker cycling is unknown at this time. The NRC Resident has been informed.time. The NRC Resident has been informed. +
02:08:00, 24 November 2012 +
48,533 +
03:18:00, 24 November 2012 +
02:08:00, 24 November 2012 +
On 11/23/2012 at approximately 1956 CST, i … On 11/23/2012 at approximately 1956 CST, it was reported that the Control Room (VC) B Chiller breaker was cycling open and closed. In order to stop the cycling, Control Building Unit Sub B was manually tripped causing the following isolations/actuations: loss of power to instrument air (IA) system containment isolation valves causing the Division 2 valves to isolate; loss of power to the low pressure switch that resulted in an automatic start of Division 2 Shutdown Service Water (SX) system; and loss of power to fuel building (VF) system ventilation Division 2 dampers resulting in a trip of the VF system. High Pressure Core Spray (HPCS) became inoperable based on inoperability of the room cooler for the associated Division 4 inverter and battery charger. Operations entered the Loss of AC Power and Automatic Isolation off-normal procedures. Following the loss of power to the VF system ventilation, at 2008, secondary containment differential pressure became positive. At 2009, power was restored to Control Building Unit Sub B and HPCS was restored to operable. At 2011, the standby gas treatment system (VG) was started and at 2013, secondary containment differential pressure was restored. Following re-energization of Unit Sub B, the IA containment isolation valves were re-opened, VG was secured, VF restarted and the Division 2 SX pump was secured.</br>The loss of secondary containment differential pressure is reportable under 10 CFR 50.72(b)(3)(v)(C) as an event or condition that could have prevented fulfillment of a safety function needed to control the release of radioactive material</br>An unplanned inoperability of HPCS reportable under 10 CFR 50.72(b)(3)(v)(D) as HPCS is a single train safety system</br>The cause of the breaker cycling is unknown at this time. The NRC Resident has been informed.time. The NRC Resident has been informed. +
Has query"Has query" is a predefined property that represents meta information (in form of a <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
97 +
00:00:00, 24 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>.
02:02:25, 2 March 2018 +
03:18:00, 24 November 2012 +
true +
false +
0.0488 d (1.17 hours, 0.00696 weeks, 0.0016 months) +
02:08:00, 24 November 2012 +
URL"URL" is a <a href="/Special:Types/URL" title="Special:Types/URL">type</a> and predefined property provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a> to represent URI/URL values.