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During the performance of a Fire Protectio … During the performance of a Fire Protection self assessment, it was discovered that a calculation for the safe shutdown analysis has an assumed action for an operator to locally depress the internal breaker trip plunger to trip the High Pressure Core Spray (HPCS) pump in response to a fire in the main control room. However, due to personnel safety concerns related to potential arc flashing events associated with this action, the remote shutdown procedure was revised to locally close the HPCS injection valve (1E22FOO4) in lieu of depressing the internal breaker trip plunger.</br>During engineering's review of this procedure and supporting calculation, it was determined that the HPCS system could be initiated due to concurrent fire induced hot short cable damage to the two automatic initiation logic instrument cables routed in the same raceway in the area. In this event, even if the HPCS breaker could be tripped or the HPCS injection valve could be closed locally, HPCS would continue to fill the reactor pressure vessel (RPV) and flood the main steam lines. Once pressure reaches the setpoint for the Main Steam Safety Relief Valves (MSSRVs), they would lift and discharge mixed-phase water through the discharge line to the suppression pool. This conservatively postulated scenario would place the MSSRVs and their associated tailpipes in an unanalyzed condition for the stresses expected during the two-phase flow event.</br>While it is not expected that a failure of the MSSRV discharge line will occur, a confirmatory analysis will be performed. Compensatory measures for Multiple Spurious Operations have been determined to be adequate until the analysis is complete.</br>The licensee added additional fire zone surveillance to operator plant walk downs and will investigate to determine further corrective actions. </br>The license has notified the NRC Senior Resident Inspector.otified the NRC Senior Resident Inspector. +
14:00:00, 8 February 2011 +
15:06:00, 8 February 2011 +
14:00:00, 8 February 2011 +
During the performance of a Fire Protectio … During the performance of a Fire Protection self assessment, it was discovered that a calculation for the safe shutdown analysis has an assumed action for an operator to locally depress the internal breaker trip plunger to trip the High Pressure Core Spray (HPCS) pump in response to a fire in the main control room. However, due to personnel safety concerns related to potential arc flashing events associated with this action, the remote shutdown procedure was revised to locally close the HPCS injection valve (1E22FOO4) in lieu of depressing the internal breaker trip plunger.</br>During engineering's review of this procedure and supporting calculation, it was determined that the HPCS system could be initiated due to concurrent fire induced hot short cable damage to the two automatic initiation logic instrument cables routed in the same raceway in the area. In this event, even if the HPCS breaker could be tripped or the HPCS injection valve could be closed locally, HPCS would continue to fill the reactor pressure vessel (RPV) and flood the main steam lines. Once pressure reaches the setpoint for the Main Steam Safety Relief Valves (MSSRVs), they would lift and discharge mixed-phase water through the discharge line to the suppression pool. This conservatively postulated scenario would place the MSSRVs and their associated tailpipes in an unanalyzed condition for the stresses expected during the two-phase flow event.</br>While it is not expected that a failure of the MSSRV discharge line will occur, a confirmatory analysis will be performed. Compensatory measures for Multiple Spurious Operations have been determined to be adequate until the analysis is complete.</br>The licensee added additional fire zone surveillance to operator plant walk downs and will investigate to determine further corrective actions. </br>The license has notified the NRC Senior Resident Inspector.otified the NRC Senior Resident Inspector. +
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, 8 February 2011 +
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>.
02:07:52, 2 March 2018 +
15:06:00, 8 February 2011 +
true +
false +
0.0458 d (1.1 hours, 0.00655 weeks, 0.00151 months) +
14:00:00, 8 February 2011 +
Unanalyzed Event Could Initiate High Pressure Core Spray and Overfill the Reactor Pressure Vessel +
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.