The inspectors identified a non- cited violation of
10 CFR Part 50, Appendix B, Criterion XVI, Corrective Action, for the failure of the licensee to identify and correct a
condition adverse to quality. Specifically, the licensee failed to implement prompt corrective actions related to a
nitrogen leak from a component associated with safety -related pressurizer power -operated relief valve (
PORV) ,
PCV -455C . The
nitrogen leak subsequently resulted in the
PORV being declared
inoperable, as well as the declaration of an Alert emergency action level classification due the Unit 2 containment atmosphere exceeding habitability limits. The licensees failure to implement prompt corrective action to correct excessive
nitrogen leakage into the Unit 2 containment was a performance deficiency. The finding was more than minor because it was associated with the equipment performance attribute of the
mitigating systems cornerstone and adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences. Specifically, the excessive
nitrogen leakage resulted in the inoperability of safety -related
PORV PCV -455C for greater than technical specification allowed outage time and atmospheric conditions in Unit 2 containment that were an immediate danger to life and health, prompting an Alert emergency declaration. Using
NRC Manual Chapter 0609,
Significance Determination Process, Attachment 4, Phase 1 - Initial Screening and Characterization of Findings, and Appendix A, Exhibit 2,
Mitigating Systems Screening Questions, the inspectors determined the finding screened as having very low significance (Green) because: (1) it was not a design deficiency; (2) did not represent a loss of system and/or function; (3) did not represent an actual loss of function of at least a single train for longer than its technical specification allowed outage time; and (4) did not result in the loss of a high safety -significant non -technical specification train. The finding was assigned a human performance cross -cutting aspect associated with consistent processes, in that the licensee did not use a systematic approach in properly assessing the potential risk significance of an increasing trend of
nitrogen leakage inside containment [H.13] .
