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The following information was provided by … The following information was provided by the licensee via phone and email:</br>As allowed by 10 CFR 50.73(a)(1), VC Summer Nuclear Station (VCSNS) is making a 60-day notification of an invalid actuation under 10 CFR 50.73(a)(2)(iv)(A).</br>At 0948 EDT, on October 3, 2025, VCSNS commenced a shutdown to repair a steam line leak. On October 4 at 2116 EDT, VCSNS was in mode 3, with the 'A' motor-driven emergency feedwater (EFW) pump providing decay heat removal. Main feedwater (MFW) had been secured per standard operating procedures. The deaerator storage tank (DAST) experienced a level decrease due to secondary-side valve leak-by. When the DAST level reached low-low level, an automatic signal was generated to secure the already secured MFW Pumps, which automatically sent an actuation signal to EFW. The low-low DAST signal is intended to secure MFW pumps to prevent damage due to a potential loss of net positive suction head at lower DAST levels. This sequence resulted in the invalid actuation of the previously secured 'B' EFW pump.</br>This actuation was not in response to an actual engineered safety feature (ESF) condition and does not meet the criteria for a valid ESF actuation. This event is being reported as a 60-day report in accordance with 10 CFR 50.73(a)(1) for an invalid actuation of the EFW System. </br>The NRC Senior Resident Inspector has been notified.nior Resident Inspector has been notified. +
14:48:00, 3 October 2025 +
58,069 +
12:26:00, 3 December 2025 +
14:48:00, 3 October 2025 +
The following information was provided by … The following information was provided by the licensee via phone and email:</br>As allowed by 10 CFR 50.73(a)(1), VC Summer Nuclear Station (VCSNS) is making a 60-day notification of an invalid actuation under 10 CFR 50.73(a)(2)(iv)(A).</br>At 0948 EDT, on October 3, 2025, VCSNS commenced a shutdown to repair a steam line leak. On October 4 at 2116 EDT, VCSNS was in mode 3, with the 'A' motor-driven emergency feedwater (EFW) pump providing decay heat removal. Main feedwater (MFW) had been secured per standard operating procedures. The deaerator storage tank (DAST) experienced a level decrease due to secondary-side valve leak-by. When the DAST level reached low-low level, an automatic signal was generated to secure the already secured MFW Pumps, which automatically sent an actuation signal to EFW. The low-low DAST signal is intended to secure MFW pumps to prevent damage due to a potential loss of net positive suction head at lower DAST levels. This sequence resulted in the invalid actuation of the previously secured 'B' EFW pump.</br>This actuation was not in response to an actual engineered safety feature (ESF) condition and does not meet the criteria for a valid ESF actuation. This event is being reported as a 60-day report in accordance with 10 CFR 50.73(a)(1) for an invalid actuation of the EFW System. </br>The NRC Senior Resident Inspector has been notified.nior Resident Inspector has 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, 3 December 2025 +
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>.
12:20:10, 5 December 2025 +
12:26:00, 3 December 2025 +
true +
false +
60.86 d (1,460.63 hours, 8.694 weeks, 2.001 months) +
14:48:00, 3 October 2025 +
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.