The Argonne National Laboratory conducted a study to develop a technically based rationale where an RandD program can be conducted. First, the development of a viable blanket for fusion is in itself a major feasibility issue, not just an engineering task. The approach of this study was to develop a number of designs in sufficient detail so that a comparison could be made between them. The most feasible blanket is lithium oxide cooled by helium and ferritic steel without a multiplier.