Browse wiki
Jump to navigation
Jump to search
At 1353 EDT on 06/28/2012, Susquehanna Ste … At 1353 EDT on 06/28/2012, Susquehanna Steam Electric Station experienced a loss of power from one of two offsite power sources when transformer 20 shutdown automatically. All ESS (Engineered Safeguards System) electrical busses fed by this transformer automatically transferred to the other offsite power source (transformer 10). Additionally, startup bus 20, which is normally fed from transformer 20, automatically transferred to transformer 10.</br>On each unit, multiple system containment isolation valves closed as a result of the electrical transient. Operators were able to reset and restore each system. On unit one, residual heat removal (RHR) shutdown cooling ceased operation during the transient. Shutdown cooling was restored within one hour by control room operators in accordance with off-normal procedures. Unit two remained at 100% power throughout the event.</br>This incident is being reported as an unplanned actuation of systems that mitigate the consequences of significant events per 10 CFR 50.72(b)(3)(iv)(A).</br>The licensee is in a 72 hour LCO on Unit 2 as a result of the loss of offsite power. All emergency diesels generators are available. The licensee is investigating the cause of the transformer 20 shutdown. </br>The NRC Resident Inspector and the Pennsylvania Emergency Management Agency (PEMA) have been notified.nagement Agency (PEMA) have been notified. +
17:53:00, 28 June 2012 +
48,055 +
20:44:00, 28 June 2012 +
17:53:00, 28 June 2012 +
At 1353 EDT on 06/28/2012, Susquehanna Ste … At 1353 EDT on 06/28/2012, Susquehanna Steam Electric Station experienced a loss of power from one of two offsite power sources when transformer 20 shutdown automatically. All ESS (Engineered Safeguards System) electrical busses fed by this transformer automatically transferred to the other offsite power source (transformer 10). Additionally, startup bus 20, which is normally fed from transformer 20, automatically transferred to transformer 10.</br>On each unit, multiple system containment isolation valves closed as a result of the electrical transient. Operators were able to reset and restore each system. On unit one, residual heat removal (RHR) shutdown cooling ceased operation during the transient. Shutdown cooling was restored within one hour by control room operators in accordance with off-normal procedures. Unit two remained at 100% power throughout the event.</br>This incident is being reported as an unplanned actuation of systems that mitigate the consequences of significant events per 10 CFR 50.72(b)(3)(iv)(A).</br>The licensee is in a 72 hour LCO on Unit 2 as a result of the loss of offsite power. All emergency diesels generators are available. The licensee is investigating the cause of the transformer 20 shutdown. </br>The NRC Resident Inspector and the Pennsylvania Emergency Management Agency (PEMA) have been notified.nagement Agency (PEMA) have been notified. +
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, 28 June 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>.
02:03:48, 2 March 2018 +
20:44:00, 28 June 2012 +
false +
0.119 d (2.85 hours, 0.017 weeks, 0.0039 months) +
17:53:00, 28 June 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.