Space power reactor in‐core thermionic multicell evolutionary (S‐prime) design

A 5‐ to 40‐kWe moderated in‐core thermionic space nuclear power system (TI‐SNPS) concept was developed to address the TI‐SNPS program requirements. The 40‐kWe baseline design uses multicell Thermionic Fuel Elements (TFEs) in a zirconium hydride moderated reactor to achieve a specific mass of 18.2 We/kg and a net end‐of‐mission (EOM) efficiency of 8.2%. The reactor is cooled with a single NaK‐78 pumped loop, which rejects the heat through a 24 m² heat pipe space radiator.