An unresolved item was identified pertaining to the biennial preventative maintenance inspections performed on the
EDG couplings. Cracks in the
coupling gland that were identified during routine maintenance inspections were not documented in the associated plant records since 1994. Description: Based on information provided by the licensee and interviews with licensee personnel, it was concluded that preventive maintenance inspections had observed cracks in the
couplings as early as 1994. The inspectors review of the
coupling inspection records for
52SV-R43-001-0 indicated that no damage existed, as shown in Attachment 3. The procedure directed the
coupling be visually examined for damage, deterioration, and loose bolts. The procedure did not contain any specific acceptance criteria pertaining to
coupling damage or deterioration. Because the earlier observation of
coupling cracks were not documented, no actions were taken to determine if the observed cracks were acceptable or required further evaluation to determine operability. The degradation of the
EDG coupling subsequently resulted in the inoperability of the 1B and 1C
EDGs. The licensee is performing a root cause investigation for the
EDG coupling problems and the contributing causes surrounding this event. This issue is unresolved pending NRC review of the licensees completed root cause investigation, and is designated as unresolved item (
URI) 05000321,366/2008008001, Review of
EDG Coupling Root Cause Evaluation
