Advancements in thermophotovoltaic (TPV) technologies enable a new alternative for the electrification of nuclear power. The Radiantly Integrated TPV-Microreactor System (RITMS) design progressed in this work utilizes direct electric conversion of thermal power radiated from the active core. A modern economics-by-design approach will be used in developing the RITMS concept by centering cost factors in studying design tradeoffs and conducting optimization searches of the design space. To empower this approach, it is necessary to develop the appropriate tools for the technical and economic analysis of an early-stage design. In order to capture the RITMS steady-state and transient physics, reduced order models that capture the coupled neutronics and thermal-radiative heat transfer are implemented. Additionally, improved economic tools informed by microreactors and optimization techniques relying on modern computational techniques are used to recommend the most economically viable RITMS design cases.