Abstract: The second volume of this report presents a safety evaluation of various design concepts and fuel forms. In that study, no consideration was given to the feasibility of the designs, to the weight penalties of the control systems or to the availability of the fuel forms. The intent was only to examine various possible methods of using strontium-90 in space. The emphasis was placed on the results which would follow from given system designs, rather than on the practical achievement of these designs. This volume of the report records the results of studies made in support of the safety evaluation effort. These studies examine the feasibility of the two basic disposal modes: intact and burnup re-entry. A conceptual design is developed for both of these disposal modes, and basic trajectory and re-entry heating analyses have been completed. This volume also deals with various propulsion and control devices that could be used to re-enter the payload and fuel at a prescribed location and reviews the present development of various fuel forms. Finally, the conclusions of the second volume are again considered in light of the practical results presented in this volume.