The Liquid Fuel Molten Salt Reactor (TMSR), which is one of the advanced reactor concepts from the Generation IV International Forum (GIF), offers advantages in economics, safety, and sustainability, making it commercially viable under current technical conditions. In TMSR, the fuel salt acts as both fuel and coolant, with delayed neutron precursors (DNPs) circulating within the primary loop, making the fuel salt an internal heat-generating fluid. As a result, the TMSR exhibits distinct transient characteristics compared to traditional solid fuel reactors. This study investigates a representative station blackout (SBO) accident using the ATHLET system analysis program to model and analyze the full-loop behavior of a 150 MW molten salt reactor, including its Passive Residual Heat Removal System (PRHRS). The results indicate that 175 s after the SBO event, the hotspot temperature in the primary circuit peaks at 711 °C, remaining well within the safety design limits. A longer shutdown rod drop time leads to greater heat accumulation in the reactor core, whereas extending the main pump coast-down period effectively mitigates the temperature rise caused by power accumulation during the initial phase of the accident. Additionally, the PRHRS connected to the secondary loop efficiently removes decay heat, ensuring that the reactor temperature remains within a safe range.