10 CFR 50.54(q) requires, in part, that a power reactor licensee follow an
Emergency Plan that meets the requirements of
10 CFR 50.47(b).
10 CFR 50.47(b) requires, in part, that a standard emergency classification and action level scheme, the bases of which includes facility system and effluent parameters, is in use by the licensee. Contrary to the above, between May 2011 and February 2012, Exelon did not have a documented basis for a useable parameter for the declaration of a General Emergency (
GE) using the
LGS South Stack effluent radiation monitor. In May 2007, Exelon implemented Revision 11 of
EP-AA-1008, Radiological
Emergency Plan Annex for Limerick Generating Station, which updated the station emergency action levels (
EALs) to the
NEI 99-01, Revision 4, standard. The new
LGS EAL scheme changed the South Stack
GE declaration threshold from 8.84E-2 uCi/cc to 2.71E-1 uCi/cc, yet the
Updated Final Safety Analysis Report listed the upper limit of that monitor as
1E-1 uCi/cc. Exelon discovered the discrepancy on February 9, 2012, and entered it into their
CAP as
IR 1324991. Exelon implemented immediate corrective actions by lowering the
GE declaration threshold to
9E-2 uCi/cc, and by contacting the monitor vendor to determine the actual indicating capability of the monitor. The vendor informed Exelon that it believed the monitor was capable of displaying an accurate indication through the entire decade of
1E-1 uCi/cc, that
1E-1 was not the upper limit of indication. Exelon developed a work order and conducted an electronic test of the monitor itself on February 14, 2012, and a system test of the sensor and monitor using a calibrated radioactive source on February 16, 2012. The results of those tests indicated that the monitor was capable of accurately indicating 2.71E-1 uC/cc. The inspectors determined that the finding was of very low safety significance (Green) in accordance with NRC
IMC 0609, Appendix B,
Emergency Preparedness Significance Determination Process, Sheet 1, because, although the licensee had not maintained their
EALs as required by
10 CFR 50.47(b), the resultant failure would not have precluded the declaration of any
GE event.
