Modelling and Evaluation of Nuclear Battery Designs and Performance

Abstract

This study evaluates six nuclear battery conversion pathways as long-duration power sources for applications where conventional recharging, replacement, or maintenance access is limited. The methodology combines a technology and materials review, theoretical maximum-output models, reduced COMSOL Multiphysics simulations, a normalized 100 W continuous-service comparison over 50 years, service-level sensitivity, radioactive-waste utilization pathways, and operating-temperature limits. The reviewed reference systems span approximately 100 nW to 10 MWe, reflecting substantially different technology scales and intended applications. The theoretical models produced radioisotope-based specific-output estimates from approximately 3.8 We/kg for the nickel-63 cantilever case to 85 We/kg for the promethium-147 betavoltaic case, while the conceptual uranium-235 fission pathway reached 31.2–44.2 kWe/kg. In the reduced simulations, geometry and boundary conditions were maintained while the nuclear source was varied, allowing the influence of source selection on each conversion pathway to be evaluated independently. Higher-energy or higher-thermal-power sources consistently increased the predicted response. Under the 100 W reference service, conventional battery storage provided the lowest service cost, while the Radioisotope Thermoelectric Generator ranked first among the evaluated nuclear references in the combined cost–mass and cost–volume indicators. Extending the fixed service analysis across six levels from 1 µW to 10 kW showed that the preferred technology changes with required power and design objective. These results provide a power-range-based framework for selecting nuclear battery technologies and identifying their most appropriate applications.