The following information was provided by the licensee via email:
As part of the extent of condition review for EN55770, [Urenco USA] UUSA identified historical instances where construction vehicles may have been allowed near buildings of concern and our process failed to identify if controls needed to be established for the activities planned. The hazards associated with those construction vehicles were not properly analyzed. UUSA failed to properly document and require controls and, during those times, available [Item Relied On For Safety] IROFS appear to be insufficient to meet the performance requirements in [10 CFR] 70.61.
No unanalyzed vehicles presently exist near buildings of concern. This event has been entered in UUSA's corrective action program as EV 149990. The plant is in a safe configuration.
The licensee notified NRC Region 2 personnel.