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The following event description is based o … The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73. </br>This report is being made under 10 CFR 50.73 (a) (2) (iv) (A) for a reportable invalid actuation.</br>On April 3, 2011, at approximately 1444 Mountain Standard Time, Palo Verde Nuclear Generating Station Unit 2 experienced an invalid actuation (start) of the 'A' Emergency Diesel Generator (EDG). EDG 'A' inadvertently started during integrated safeguards surveillance testing to demonstrate that the EDG overspeed trip is not bypassed. Prior to the test, the EDG overspeed governor was actuated, but the butterfly valve was not verified to be fully closed as required. The valve closure actuates a limit switch which activates the interlock that prevents the EDG start following an overspeed trip. The test requires the operator to ensure the butterfly valve is fully closed because it may not fully close as the EDG is not running when it is actuated for the overspeed test. </br>When the demand signal was inserted, the EDG started unexpectedly since the butterfly valve was not fully closed and the limit switch was not engaged. EDG 'A' Train completely actuated in the Emergency Mode and the EDG came up to rated speed and voltage as designed. The supporting 'A' train Essential Spray Pond System, used for engine cooling, was already running prior to the test. The Essential 'A' Train EDG Exhaust Room air handling unit started as required. </br>No damage occurred to the EDG or related equipment as a result of the unplanned actuation. The EDG was secured and the test was successfully re-performed.</br>This report is not considered an LER.</br>The licensee has notified the NRC Resident Inspector.e has notified the NRC Resident Inspector. +
21:44:00, 3 April 2011 +
46,898 +
15:13:00, 27 May 2011 +
21:44:00, 3 April 2011 +
The following event description is based o … The following event description is based on information currently available. If through subsequent reviews of this event, additional information is identified that is pertinent to this event or alters the information being provided at this time, a follow-up notification will be made via the ENS or under the reporting requirements of 10CFR50.73. </br>This report is being made under 10 CFR 50.73 (a) (2) (iv) (A) for a reportable invalid actuation.</br>On April 3, 2011, at approximately 1444 Mountain Standard Time, Palo Verde Nuclear Generating Station Unit 2 experienced an invalid actuation (start) of the 'A' Emergency Diesel Generator (EDG). EDG 'A' inadvertently started during integrated safeguards surveillance testing to demonstrate that the EDG overspeed trip is not bypassed. Prior to the test, the EDG overspeed governor was actuated, but the butterfly valve was not verified to be fully closed as required. The valve closure actuates a limit switch which activates the interlock that prevents the EDG start following an overspeed trip. The test requires the operator to ensure the butterfly valve is fully closed because it may not fully close as the EDG is not running when it is actuated for the overspeed test. </br>When the demand signal was inserted, the EDG started unexpectedly since the butterfly valve was not fully closed and the limit switch was not engaged. EDG 'A' Train completely actuated in the Emergency Mode and the EDG came up to rated speed and voltage as designed. The supporting 'A' train Essential Spray Pond System, used for engine cooling, was already running prior to the test. The Essential 'A' Train EDG Exhaust Room air handling unit started as required. </br>No damage occurred to the EDG or related equipment as a result of the unplanned actuation. The EDG was secured and the test was successfully re-performed.</br>This report is not considered an LER.</br>The licensee has notified the NRC Resident Inspector.e has 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, 27 May 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>.
02:07:02, 2 March 2018 +
15:13:00, 27 May 2011 +
false +
false +
53.728 d (1,289.48 hours, 7.675 weeks, 1.766 months) +
21:44:00, 3 April 2011 +
Overspeed trip + and Overspeed +
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.