At 1929 EDT, both off-site A.C. power sources to Sequoyah were declared inoperable due to the effects of inclement weather on the
TVA transmission system. This determination was made after a review of grid conditions confirmed that pre-analyzed grid/offsite power requirements could not be met. Both Sequoyah Units have entered TS
LCO 3.8.1.1, action d, for two inoperable offsite power sources. It has not been determined when this condition will no longer exist.
Although inoperable, off-site A.C. sources remain connected to Sequoyah; emergency diesel generators are not running nor required to be at this time.
T.S. LCO 3.8.1.1, action d, requires verifying EDG operability within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and restoration of both offsite power sources within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or placing both Units in mode 3.
The licensee informed the NRC Resident Inspector.
- * * UPDATE FROM JEFF EPPERSON TO PETE SNYDER AT 0203 EDT ON 4/28/11 * * *
As of 0119 EDT the licensee has two operable offsite power sources qualified through transmission and reliability analysis. The licensee exited their LCO Condition. The grid condition is now yellow.
Notified R2IRC (Gody).
