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100  +
On November 16, 2016 at 1045 (EST), Unit 2On November 16, 2016 at 1045 (EST), Unit 2 B ESS (Engineered Safeguards System) Bus Sync Selector switch failed and was unable to be switched out of the ON position. The failure rendered all other sync selector switches associated with Emergency Diesel Generators and Off-Site supplies to the ESS buses unable to fulfill their intended function of allowing manual transfer between power supplies to the ESS buses. This resulted in the inability of Unit 1 and Unit 2 to comply with SR (Surveillance Requirements) 3.8.1.8 and 3.8.1.16 thus requiring declaration of Operating AC Sources inoperable. This condition could have prevented the fulfillment of the safety function of systems required to maintain the reactor in a safe shutdown condition, remove residual heat, control the release of radioactive material, and mitigate the consequences of an accident. Subsequent actions were taken in accordance with station procedures to remove fuses for the affected sync circuit, restoring the manual transfer function to all but the Unit 2 B ESS bus. One Emergency Diesel and one offsite source remain inoperable with the fuses removed. </br>At no time were any ESS buses disconnected from offsite power. All ESS buses remained capable of being automatically energized from their respective emergency diesel in an emergency.</br>The licensee has notified the NRC Resident Inspector.e has notified the NRC Resident Inspector.  +
15:45:00, 16 November 2016  +
52,369  +
17:13:00, 16 November 2016  +
15:45:00, 16 November 2016  +
On November 16, 2016 at 1045 (EST), Unit 2On November 16, 2016 at 1045 (EST), Unit 2 B ESS (Engineered Safeguards System) Bus Sync Selector switch failed and was unable to be switched out of the ON position. The failure rendered all other sync selector switches associated with Emergency Diesel Generators and Off-Site supplies to the ESS buses unable to fulfill their intended function of allowing manual transfer between power supplies to the ESS buses. This resulted in the inability of Unit 1 and Unit 2 to comply with SR (Surveillance Requirements) 3.8.1.8 and 3.8.1.16 thus requiring declaration of Operating AC Sources inoperable. This condition could have prevented the fulfillment of the safety function of systems required to maintain the reactor in a safe shutdown condition, remove residual heat, control the release of radioactive material, and mitigate the consequences of an accident. Subsequent actions were taken in accordance with station procedures to remove fuses for the affected sync circuit, restoring the manual transfer function to all but the Unit 2 B ESS bus. One Emergency Diesel and one offsite source remain inoperable with the fuses removed. </br>At no time were any ESS buses disconnected from offsite power. All ESS buses remained capable of being automatically energized from their respective emergency diesel in an emergency.</br>The licensee has notified the NRC Resident Inspector.e has notified the NRC Resident Inspector.  +
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100  +
00:00:00, 16 November 2016  +
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>.
01:43:48, 2 March 2018  +
17:13:00, 16 November 2016  +
false  +
0.0613 d (1.47 hours, 0.00875 weeks, 0.00201 months)  +
15:45:00, 16 November 2016  +
Failure of Unit 2 B Engineered Safeguards System Bus Sync Selector Switch  +
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