Investigating the Impact of Various Molten Salt Combinations on Reactor Criticality and Thermal Neutron Flux Distribution in SD-TMSR

Abstract Molten salt reactors represent a groundbreaking advancement in both advanced and conventional reactor technologies, leveraging fluid fuel/coolant salt for enhanced temperature control and thermal efficiency. In the pursuit of optimizing molten salt reactor efficiency, our research focuses on exploring diverse salt compositions within the structured framework of the SD-TMSR core geometry. This investigation maintains a fixed hexagonal lattice structure, distinguishing two core zones, including a crucial blanket region for thorium-based fuel breeding. The study systematically alters salt composition with various isotopes, specifically fissile (U-233) and fertile (Th-232) materials, providing critical insights into reactor criticality and thermal neutron flux distribution. The molten salts examined here include different combinations of materials listed as lithium (Li), fluoride (F), beryllium (Be), sodium (Na), zirconium (Zr), and rubidium (Rb). Nine molten salts were tested for their criticality performance, and the reactor reached criticality with only four of them. Therefore, the neutron flux distribution simulations were performed only with those salts. The primary purpose of the research is to compare the performance of the core reactivity with different molten salts and identify the most suitable salt for SD-TMSR. Through the broadening of our knowledge and understanding of the complexities in MSR design, this study emphasizes the crucial position of molten salt reactors in advanced next-generation nuclear technology, establishing them as robust and sustainable contributors to the global energy perspective.