A self-revealing finding (
FIN) of very low safety significance (Green) was identified for
PPL staffs failure to follow their
CAP procedure, NDAP-QA-0702, Action Request and Condition Report Process, in response to an identified issue with the
FW system. Specifically, on August, 23, 2011,
PPLs staff did not initiate an action request (
AR) or condition report (CR) after determining that
ICS digital
FW valve control needed to be placed in Manual Valve Control mode prior to de-energizing the 3A motor operated valve (
MOV) in order to prevent a loss of all
FW flow. This issue went unaddressed and subsequently on December 19, 2012, Unit 2 scrammed on low
RPV water level when operators, while attempting to open the stuck 3A valve, opened the 3A valve power supply breaker with the A
RFP FW valve controls in automatic causing a loss of all normal
FW. The
PPL staff entered this issue into the
CAP as CR 1653480. The finding was more than minor because it was associated with the human performance attribute of the
Mitigating Systems Cornerstone and adversely impacted the objective to ensure the availability, reliability and capability of systems that respond to
initiating events to prevent undesirable consequences (i.e., core damage). The finding was evaluated using NRC
IMC 0609, Attachment 0609.04, Initial Characterization of Findings, and Appendix A, User Guidance for Significance Determination for At-Power Situations, and screened as very low safety significance (Green) per Exhibit 2. The inspectors determined that this finding had a cross-cutting aspect in the area of Problem Identification and Resolution,
CAP, because
PPLs staff did not implement the
CAP with a low threshold for identifying issues completely, accurately, and in a timely manner commensurate with their safety significance. Specifically,
PPLs staff did not identify non-conforming issues for
FW valve control, design and operation that eventually led to a loss of normal
FW and
scram of Unit 2 on December 19, 2012.
