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On 03/11/06 at approximately 0432 hours, w … On 03/11/06 at approximately 0432 hours, with Susquehanna Unit 1 in the Refueling Mode (0% power), the Unit experienced a partial isolation of Primary Containment isolation valves. The actuation occurred when a blown fuse disrupted power to a containment isolation logic relay. The inboard isolation valve to the 'B' Drywell Floor Drain Sump and the Containment Instrument Gas purge supply valve to the TIP indexer both closed. The 'A' Standby Gas Treatment system fan and the 'A' Reactor Building Recirculation fan successfully auto started during the event.</br>This event constitutes an invalid system actuation and is reportable under 10CFR 50.73(a)(2)(iv)(A). The condition meets the criteria of 10CFR 50.73(a)(2)(iv)(B)(2) because a general containment isolation signal affected containment isolation valves in more than one system. This notification is being provided via a 60-day optional phone call as permitted under 10CFR 50.73(a)(1) in lieu of a written LER.</br>As stated above, both valves affected by the invalid signal fulfilled their isolation function by successfully closing. At the time of the event, no other Primary Containment isolation valve was being maintained in a manner that required re-positioning. There were no challenges to the Reactor as a result of this event. The plant responded as expected.</br>Following replacement of the subject fuse, the isolation logic was successfully reset and affected equipment was restored to the desired status.</br>The licensee notified the NRC Resident Inspector.ensee notified the NRC Resident Inspector. +
09:32:00, 11 March 2006 +
42,489 +
09:35:00, 11 April 2006 +
09:32:00, 11 March 2006 +
On 03/11/06 at approximately 0432 hours, w … On 03/11/06 at approximately 0432 hours, with Susquehanna Unit 1 in the Refueling Mode (0% power), the Unit experienced a partial isolation of Primary Containment isolation valves. The actuation occurred when a blown fuse disrupted power to a containment isolation logic relay. The inboard isolation valve to the 'B' Drywell Floor Drain Sump and the Containment Instrument Gas purge supply valve to the TIP indexer both closed. The 'A' Standby Gas Treatment system fan and the 'A' Reactor Building Recirculation fan successfully auto started during the event.</br>This event constitutes an invalid system actuation and is reportable under 10CFR 50.73(a)(2)(iv)(A). The condition meets the criteria of 10CFR 50.73(a)(2)(iv)(B)(2) because a general containment isolation signal affected containment isolation valves in more than one system. This notification is being provided via a 60-day optional phone call as permitted under 10CFR 50.73(a)(1) in lieu of a written LER.</br>As stated above, both valves affected by the invalid signal fulfilled their isolation function by successfully closing. At the time of the event, no other Primary Containment isolation valve was being maintained in a manner that required re-positioning. There were no challenges to the Reactor as a result of this event. The plant responded as expected.</br>Following replacement of the subject fuse, the isolation logic was successfully reset and affected equipment was restored to the desired status.</br>The licensee notified the NRC Resident Inspector.ensee notified the NRC 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>.
00:00:00, 11 April 2006 +
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>.
02:18:58, 2 March 2018 +
09:35:00, 11 April 2006 +
false +
false +
31.044 d (745.05 hours, 4.435 weeks, 1.021 months) +
09:32:00, 11 March 2006 +
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.