Available at: https://digitalcommons.calpoly.edu/theses/3191
Date of Award
12-2025
Degree Name
MS in Mechanical Engineering
Department/Program
Mechanical Engineering
College
College of Engineering
Advisor
Andrew Kean
Advisor Department
Mechanical Engineering
Advisor College
College of Engineering
Abstract
Nuclear Fluoride Salt-Cooled High-Temperature Reactors (FHRs) have the potential to greatly improve nuclear technology in terms of safety and cost. By combining molten salt coolant technology from the Molten Salt Reactor (MSR) and TRISO fuel technology from the Very High Temperature Gas Reactor (VHTR), FHRs may operate at significantly lower pressures than Light Water Reactors (LWRs) and with a more robust fuel source that is excellent at containing fission products. However, as no FHR has been built, there are still many design questions to address. This thesis uses transient computer modeling and simulation to investigate how an FHR could potentially interface with a Rankine steam cycle to produce electricity, without freezing the molten salt. The simulation results show that implementing an intermediate loop raised the steam generator wall temperatures, on the salt side, from approximately 25°C below the salt freezing point to approximately 25°C above the salt freezing point. However, this margin drops to below zero at lower power levels (less than 50% reactor power). The model built in this research gives insights into various dynamics and applications of an FHR powered Rankine cycle, including the prevention of molten salt freezing, power ramp responses, and load-following.