A finding of very low safety significance and associated
NCV of
10 CFR Part 50.59, Changes, Tests, and Experiments, was identified by the inspector for the licensees failure to provide a documented basis that a change in the method of evaluation for small
bore torus attached piping systems as defined in the Plant Unique Analysis Report (PUAR) for torus attached piping did not require prior NRC approval. Because the issue affected the NRCs ability to perform its regulatory function, this issue was evaluated using the traditional enforcement process. The finding was determined to be more than minor because the inspector could not reasonably determine that the change would not have ultimately required NRC prior approval. The finding was determined to be of very low safety significance by the NRCs
significance determination process because it was a design deficiency that did not result in actual loss of safety function. This finding had a cross-cutting aspect in the area of Human Performance, Decision Making, because the licensee failed to use conservative assumptions in licensee did neither verify the validity of their justification to not reevaluate the
HPCI steam exhaust vacuum breaker piping attached to the modified
HPCI steam exhaust piping nor identify adverse consequences due to changes in the
HPCI steam exhaust piping resonant frequency content
