Several failures of the LOCA/LOSP timer cards were identified over the period July 2008 through March 2009. The licensee determined that probable causes for these failures were degraded power supplies to these cards and potential defects identified on the timer cards. These issues were captured in the licensees corrective action program as CRs 2008107899, 2009101880 and 2009102221. The licensee performed an extent of condition review and all affected timer cards were identified, refurbished and tested satisfactorily prior to returning to them to service. The licensee is performing a root cause investigation for the LOCA/LOSP timer card failures and the contributing causes surrounding these events. The inspectors will review the root cause and determine if a performance deficiency existed and evaluate
past operability of these timer cards. This issue is unresolved pending NRC review of the licensees completed root cause investigation and is designated as
URI 05000366/2009002-04, Failures of theUnit-2
EDG LOCA/LOSP Timer Cards
