NEUTRONIC STUDY OF MOLTEN SALT REACTOR DESIGN FOR UNIFORM POWER DENSITY DISTRIBUTION WITH POWER VARIATIONS OF 150, 450 AND 1000 MWTH

• Main Author: Variastuti, Marisa
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/77668
• Institution: Institut Teknologi Bandung

The Molten Salt Reactor (MSR) is one of the Generation IV reactors that utilizes fuel and coolant dissolved in a molten salt mixture. This research focuses on neutronics studies of MSR, referencing the reactor designs of FUJI 12 and FUJI U3 developed by the International Thorium Molten-Salt Forum (ITMSF) in Japan. Lithium and Beryllium Fluoride (FliBe) are used as coolants, and the fuel mixture consists of 233UF4-ThF4. The Power Peaking Factor (PPF) is a crucial parameter that needs to be considered to ensure reactor stability, safety, and efficiency. This study discusses power density distribution in the reactor core by calculating PPF to enhance reactor safety margins and reduce the likelihood of high power density at specific points that could lead to reactor core failure in the MSR. Key parameters discussed in this study include the reactor core configuration and fuel composition in each region over a 2000-day reactor operating period. Analysis is performed for three different thermal powers: 150, 450, and 1000 MWth, to determine PPF characteristics from low to high power levels. Calculations are carried out using SRAC2006 with the PIJ and CITATION modules. Additionally, this research involves the implementation of a fuel feeding process using a Bash-based Linux programming language to facilitate the process. The process involves the periodic addition of Thorium and Flibe and the removal of toxic fission gas products every 20 days over the 2000-day reactor operation period.The results obtained from this study indicate that an MSR with a four-region core design produces a more balanced power distribution, improved PPF values, and a well-critical reactor condition over a 2000-day operating period. The fuel feeding process can enhance the reactivity of the reactor, and the conversion ratio value also increases due to the addition of fertile material every 20 days during the 2000 days of reactor operation, which triggers an increase in the fission reactions in the reactor core.