A technology assessment of heat exchangers and compressors to enable high efficiency Brayton cycle designs for nuclear power plants

The Brayton cycle (BC) has remained desirable in the nuclear industry due to its theoretical ability to compactly and efficiently generate heat from high-temperature heat sources. However, despite significant research, the deployment of BCs in industrial applications remains largely conceptual. This work develops a feasibility-informed optimization framework for nuclear Brayton cycles that compares more than 400 configurations across reactor outlet temperatures, working fluids, cycle layouts, and component-performance assumptions. Rather than reporting only thermodynamic optima, the study translates optimized cycle results into compressor and recuperator requirements, so that the attainable efficiency envelope can be distinguished from configurations that are attractive in theory but difficult to realize in practice. Indirect cycles were compared to direct cycles with the former showing a marked improvement of around 4% over the latter. The work shows that the efficiency of optimized BCs can vary by more than 10% depending upon achievable values of heat exchanger pinch points and pressure drops. This result demonstrates that the ranking of candidate cycle architectures is strongly constraint-dependent and that component performance assumptions can matter as much as cycle topology in determining the best design choice. To identify options that are most promising for early adoption, the work presents a technology feasibility study of the conceptual cycles, including compressor and recuperator requirements. These requirements are compared with published parameters from known demonstrations and material limits to technology readiness levels of key components. With the advent of multiple new microreactor and advanced reactor concepts, this work clarifies the performance and limitations of realistic and suitable BC configurations for integration with advanced nuclear power plants.