Additional spent fuel storage capacity is needed at many nuclear power plant sites where spent fuel storage pools have either reached or are expected to reach maximum capacities before spent fuel can be removed. This analysis examines certain aspects of Transportable Storage Casks (TSC) to assist in the determination of their feasibility as an option for at-reactor dry storage. Factors that can affect in-transport reliability include: the quality of design, development, and fabrication activities; the possibilities of damage or error during loading and closure; in-storage deterioration or unanticipated storage conditions; and the potential for loss of storage period monitoring/measurement data necessary for verifying the TSC fitness-for-transport. The reported effort utilizes a relative reliability comparison of TSCs to Transport-Only Casks (TOC) to identify and prioritize those issues and activities that are unique to TSCs. TSC system recommendations combine certain design and operational features, such as in-service monitoring, pretransport assessments, and conservation design assumptions, which when implemented and verified, should sufficiently ensure that the system will perform as intended in a later transport environment.