Baseline design of the thermoelectric reactor space power system

An extensive review of design alternatives for a nuclear reactor space power system capable of delivering 10 to 100 kW/sub e/ has led to the selection of a heat-pipe-cooled fast spectrum reactor with a thermoelectric power conversion system. The reactor design features a laminated core configuration with sheets of molybdenum - extending across the full diameter of the core - interspersed between layers of UO2. Reactor heat is transferred by these sheets from the UO2 to an array of 90 Mo/Na heat pipes that are spaced so that each receives equal power from an essentially uniform fuel loading in the core. This heat is transported by these heat pipes around the LiH shield to a ring of high-power-density thermoelectric modules constructed from modified SiGe alloys. Conversion takes place over a temperature interval of 1375 to 775 K with an efficiency of 9%. Residual heat is rejected by a conical radiator that is constructed from cross-coupled beryllium heat pipes. The discussion of this system will emphasize manifestations of the overriding design consideration - that of avoiding both single point failure and propagating failure chains. A technology readiness program has been initiated to demonstrate that key components of the reactor/thermoelectric power system can be constructed to meet performance objectives for the required seven year lifetime. These components include the fuel configuration, the core, radiator and cross-coupling heat pipes, the thermoelectric modules and the shield, reflector, and control assemblies. This problem is described and key results are discussed