The inspectors identified a performance deficiency involving a
NCV of
Technical Specifications 5.4.1, related to the unauthorized and improper storage of loose material in the designated material exclusion area around the Unit 1 and Unit 2 transformers. The inspectors identified this issue on a number of occasions. After each occurrence, the licensee took immediate corrective actions by either removing loose material out of the transformer yard or properly securing the material being stored in the transformer yards. The inspectors concluded that the finding was more than minor because loose/unsecured material in the transformer yards increased the likelihood of those events occurring that could upset plant stability. Specifically, during high wind speed conditions the loose material could have affected the main power transformers and could have caused a unit trip or it could have affected the station auxiliary transformers that could increase the likelihood of a loss of
mitigating systems. In each case however, the inspectors concluded that there was not enough debris in either area to affect both transformers simultaneously. The finding was determined to be of very low safety significance because it did not contribute to both the likelihood of a
reactor trip and the likelihood that mitigating equipment or functions would not be available. The primary cause of this
NCV was related to the cross-cutting aspect in the area of Human Performance in the Work Practices component (Item H.4.(b)). Multiple groups, including contractors and operators failed to properly implement the procedures for control of material in the transformer exclusion zones. The preliminary cause appeared to be inadequate supervisory and management oversight of work activities
