Green . A self -revealed finding and associated
NCV occurred on January 10, 2017, when the licensee caused a loss of a qualified off-site circuit while opening a disconnect on the Unit 2 reserve feed transformer.
Regulatory Guide 1.33 requires procedures for operating the onsite and offsite electrical distribution system; however the licensee did not develop a procedure or instruction for operating the electrical distribution system. Licensee personnel opened a disconnect to the Unit 2 reserve auxiliary transformer with the transformer energized but unloaded. This action resulted in trip of an upstream breaker and unplanned Technical Specification entry for the opposite unit. The licensee recovered the
offsite circuit for Unit 1. The licensee entered the issue into the corrective action program (
CAP) as Action Request (
AR ) 2017 0346. The inspectors determined that the failure to develop, implement , and maintain procedures or work instructions for the electrical distribution system was a performance deficiency. The performance deficiency impacted the mitigating system performance objective of ensuring the availability of systems that respond to
initiating events. The finding was not greater than green in accordance with
IMC 0609, Appendix A, Exhibit 2, dated June 19, 2012, because the answer to all four questions was no. The finding does not include a cross -cutting aspect because the licensee followed guidance for operating the disconnect that existed for the life of the plant and is therefore not reflective of current performance.