Advancements in americium-based ceramics for Radioisotope Power Systems: Material selection, fabrication and thermoelectric effect demonstration

This work provides an in-depth analysis of the extensive research and development activities on americium-based ceramics for space applications, particularly as heat source for radioisotope power generation. Our pioneering efforts focus on synthesizing and characterizing various americium ceramics with fluorite, monazite, perovskite, zircon, and pyrochlore structures, and assessing their potential for use in Radioisotope Power Systems (RPSs). This study identifies uranium-stabilised cubic americium oxide as the best candidate among the ceramic forms analysed, due to its superior stability and performance under extreme conditions relevant to space missions. The review emphasises the unique facilities and methodologies employed, including remote-handling techniques and advanced material characterization, to overcome the challenges posed by the high radiation dose and specific activity of 241 Am when working with gram quantities. • Several ceramics with high americium content were evaluated for use in radioisotope power systems. • Their potential was assessed based on ten essential criteria. • Cubic americium oxide stabilised with uranium was identified as the most promising candidate. • A gram-scale pellet of U-stabilised AmO 2 (3 g) was produced in a dedicated nuclear facility. • A proof of concept demonstrates the feasibility of using the heat generated by U-stabilised AmO 2 for electricity supply.