Availability information contained within the Centralized Reliability Data Organization (CREDO) liquid-metal reactor (LMR) data base is presented, and the availability critical items lists are developed. Individual components are ranked in prioritized lists from worst to best performers from an availability standpoint. Availability, as used here, is assumed to be an inherent characteristic of the component and is not necessarily assumed to be related to plant operability. A major observation is that of ∼5000 components analyzed at each reactor site, a few components have a much higher unavailability factor than the average. In particular, 15 components contribute 93, 77, and 87% of the total system unavailability for the Experimental Breeder Reactor II, the Fast Flux Test Facility, and the Japanese Experimental Fast Reactor (JOYO), respectively. Critical components common to all three sites are mechanical pumps and electromagnetic pumps. By identifying components in this way, site personnel will be more efficient in their attempts at increasing overall system availability; i.e., attention can be focused on components that have a high contribution to overall system unavailability. All three sites demonstrate that low maintainability (i.e., long repair times) is about twice as likely to contribute to unavailability of a component than unreliability (i.e., high failure rates). The analyses were conducted using data and information from CREDO, the largest repository of LMR component reliability data in the world. The system is cosponsored by the U.S. Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan. The CREDO data base contains information on a population of >20 000 components and addresses ∼1500 events (i.e., abnormal component occurrences). A conservative estimation is that total component operating hours approaches 2.2 billion hours.