TS 3.7.8,
Control Room Emergency Ventilation System (
CREVS), requires two
CREVS trains
operable during modes 1, 2, 3, 4, and during movement of irradiated fuel assemblies. With one
CREVS train
inoperable due to excessive bypass flow,
TS 3.7.8, Condition E, is required to be entered. The required action is to restore
CREVS train to
operable status within seven days. This action was not completed within the required completion time because the issue was discovered after the required completion time had expired. Contrary to the above, one train of
CREVS was
inoperable from September 22, 2013, through October 3, 2014, due to the 12 PLFF discharge
damper failure in its partially open position. As a result, Exelon operated in a condition prohibited by TS for approximately 4 days. Exelon entered this issue into their
CAP as CR-2013-007736. In accordance with
IMC 0609.04, Initial Characterization of Findings, and
IMC 0609, Appendix A, The
Significance Determination Process (
SDP) for Findings at Power, Exhibit 3,
Barrier Integrity Screening Questions, the inspectors determined that this finding is of very low safety significance (Green) because the finding only represented a degradation of the radiological barrier function provided for the control room.
