During investigation of a documentation discrepancy, a potential cable size and breaker mismatch was identified to exist in a non-safety related
DC panel. Initial evaluation has shown that the cable may heat and be potentially damaged if exposed to a 'smart' high impedance fault for an extended period. This discovered condition has not been previously analyzed for
NFPA [National Fire Protection Association] 805 common enclosure circuit coordination.
Fire watches were established as a compensatory measure immediately following identification of the issue on April 8, 2013. An initial review of fire protection analysis was completed on April 16, 2013. Fire watches remain in place until a modification which will restore coordination is complete.
The licensee notified the NRC Resident Inspector.
- * * RETRACTION FROM JOHN CAVES TO CHARLES TEAL AT 1400 EDT ON 6/4/13 * * *
An analysis demonstrated that adjacent cables in the common enclosure would not be damaged, therefore, the condition does not significantly degrade plant safety.
The licensee has notified the NRC Resident Inspector. Notified R2DO (McCoy).