Design optimization and integration of nickel/Haynes-25 AMTEC cells into radioisotope power systems

A number of nickel/Haynes-25, vapor anode, multi-tube Alkali Metal Thermal-to-Electric Conversion (AMTEC) cell designs, similar to the Pluto/Express series cells, were developed and optimized for improved performance. Optimization calculations investigated the effects of changing the number and length of the sodium Beta"-Alumina Solid Electrolyte (BASE) tubes, the cell length and the condenser temperature on the cell's electric power output, conversion efficiency, temperature margin and the temperatures of the BASE brazes and the evaporator. Various options of integrating the high performance nickel/Haynes-25 cells with (PuO2)-Pu-238 General Purpose Heat Source (GPHS) modules, into the electric power system's configuration proposed by Advanced Modular Power Systems, were explored for satisfying an End of Mission (EOM) electric power requirement of 130 W-e at 28 V de for 10- to 15-year space missions. The power systems' integration options explored included changing the number of GPHS modules and the number of AMTEC cells in the generator and using either fresh or aged (PuO2)-Pu-238 fuel in the GPHS modules. (C) 2000 Elsevier Science Ltd. All rights reserved.