The concept of a nuclear energy system consisting of numerous small, specialized nuclear reactors providing heat or electricity for localized/regional purposes is considered. It is envisaged that a “parent” nuclear facility would sustain the fuel needs of many small nuclear energy “satellites” and possibly provide other fuel-management services. The choice of fuel cycle and the operational features of these satellites may be determined by the form of energy required, public and social preferences, and institutional factors. Three distinct classes of distributed systems, each based on extensions of existing nuclear technology, are identified and discussed.