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On 5/3/2020 at 1100 EDT, Operations identi … On 5/3/2020 at 1100 EDT, Operations identified a step change in the Main Control Room ambient noise. The cause of the noise was a rise in vibrations on the Number 11 fan motor of the Main Control Room Ventilation Circulating Fan. Another step change in noise occurred and Operations swapped from the Number 11 fan motor to its redundant Number 12 fan motor, but the noise and vibrations did not improve. The two independent motors are connected to the blower shaft with belts on either end of the shaft. This entire fan and motor assembly is contained within the Main Control Room ventilation ducting and is not visible. At 1118 EDT, Operations shut off the Main Control Room Ventilation Circulating Fan due to Number 11 fan motor vibrations, declared the Main Control Room Air Treatment System inoperable, and entered the Technical Specification 3.4.5.e, 7-day action statement.</br>At 1750 EDT, Maintenance entered the ductwork and informed Operations that the Number 11 fan bearing had catastrophically failed and because of the extent of damage and close physical proximity to the Number 12 fan motor, jeopardized its continued operation. As a result, Operations also declared the Number 12 fan motor inoperable and determined the event was reportable as a loss of safety function per 10 CFR 50.72(b)(3)(v)(D).</br>The licensee notified the NRC Resident Inspector.ensee notified the NRC Resident Inspector. +
21:50:00, 3 May 2020 +
54,692 +
22:28:00, 3 May 2020 +
21:50:00, 3 May 2020 +
On 5/3/2020 at 1100 EDT, Operations identi … On 5/3/2020 at 1100 EDT, Operations identified a step change in the Main Control Room ambient noise. The cause of the noise was a rise in vibrations on the Number 11 fan motor of the Main Control Room Ventilation Circulating Fan. Another step change in noise occurred and Operations swapped from the Number 11 fan motor to its redundant Number 12 fan motor, but the noise and vibrations did not improve. The two independent motors are connected to the blower shaft with belts on either end of the shaft. This entire fan and motor assembly is contained within the Main Control Room ventilation ducting and is not visible. At 1118 EDT, Operations shut off the Main Control Room Ventilation Circulating Fan due to Number 11 fan motor vibrations, declared the Main Control Room Air Treatment System inoperable, and entered the Technical Specification 3.4.5.e, 7-day action statement.</br>At 1750 EDT, Maintenance entered the ductwork and informed Operations that the Number 11 fan bearing had catastrophically failed and because of the extent of damage and close physical proximity to the Number 12 fan motor, jeopardized its continued operation. As a result, Operations also declared the Number 12 fan motor inoperable and determined the event was reportable as a loss of safety function per 10 CFR 50.72(b)(3)(v)(D).</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, 3 May 2020 +
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>.
16:40:28, 15 January 2021 +
22:28:00, 3 May 2020 +
0.0263 d (0.63 hours, 0.00375 weeks, 8.62974e-4 months) +
21:50:00, 3 May 2020 +
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