Licensee Event Report 05000272/2013-004-00 describes an
unanalyzed condition in which
PSEG identified their
DC ammeter circuits were unfused. Specifically,
PSEG did not provide overcurrent protection for wiring associated with
DC ammeter indication in the control room to prevent wires from overheating due to fire-induced faults and excessive currents flowing through the cable. With enough current flowing through the cable, the potential exists that the overloaded ammeter wiring could damage system wiring or adjacent safety-related circuits in the cable trays needed for post-fire
safe shutdown. This condition could result in a loss of the associated
safe shutdown components or a secondary fire in another fire area. The failure to protect
safe shutdown cables from the effects of postulated fires was a performance deficiency. This performance deficiency was a violation of Operating License Condition 2.C.(5) for Unit 1 and 2.C.(10) for Unit 2, which requires in part, post-fire
safe shutdown cables remain free of the effects of fire-induced cable faults during postulated fires. Contrary to the above,
PSEG identified they failed to meet this requirement and the condition existed since initial construction of both units. The issue was more than minor because it was associated with the protection against external events (fire) attribute of the
mitigating systems cornerstone and it adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. The team determined that the finding was of very low safety significance (Green), based
IMC 0609, Appendix F, Fire Protection
Significance Determination Process (
SDP), Phase 2 screening criteria. The finding screened to Green based upon, task number 2.3.5, because the affected cables were routed in alternate shutdown fire areas that are protected by detection and automatic suppression systems. Additionally, the cable construction is
IEEE 383 (
thermoset) with a heavy bronze/copper metal shield tied to station ground which decreases the likelihood of inter-cable and intra-cable interactions. Based on a team walkdown, the team determined that the ammeter cable routing was not routed near a credible fire ignition source in the affected fire areas. Because this finding is of very low safety significance and had been entered into
PSEGs corrective action program (notification 20630018), this violation is being treated as a Green, licensee identified
NCV consistent with the NRCs
Enforcement Policy.
