| Fluoride salt-cooled high-temperature reactors (FHRs) face a number of challenges similar to those faced by other Generation IV advanced reactor concepts. Predicting heat transfer in these systems accurately and reliably is one major challenge. Another is ensuring the safety of these systems during challenging operating conditions across the design basis envelope. Finally, achieving good economics to compete in a modern power generation portfolio is necessary for moving any nuclear power plant concept past the pre-conceptual stage. This dissertation attempts to support, from a thermal-hydraulics research standpoint, the case that the FHR can attain these goals. The dissertation focuses on several aspects of the design. The common thread through the different studies is ultimately rooted in improving plant safety and economics.;This dissertation has four major contributions in support of the FHR: experimental investigation of a directional direct reactor auxiliary cooling system (DRACS) heat exchanger (DHX), experimental investigation of twisted versus plain tube heat transfer for molten salt heat exchangers, and two computational studies, one on DRACS reliability and one on heat exchanger optimization. The results for the four studies are presented and discussed. The directional DHX study was performed using a hydrodynamic experimental setup with water as a working fluid and heat transfer performance inferred. The experimental heat transfer work was performed using a simulant fluid, Dowtherm A, to match the important non-dimensional heat transfer parameters. The computational DRACS reliability study was performed using MATLAB and RELAP5-3D, and the computational heat exchanger optimization study was performed using Python and available metaheuristic algorithms. The implications of the various studies are tied together in the conclusions section, with suggestions for future work. |
