Analyses of the shutdown system and transients scenarios for the dual fluid reactor concept with metallic molten fuel

In this study, building on the author’s previous experience in the simulation of the MSRE system, a similar approach was used to model the dual fluid reactor design. The work was done using a modified version of the system code TRACE capable of simulating molten salt and metal flows and the transport of the neutron precursors with the flowing fuel, and the Monte Carlo based Serpent code to generate the appropriate core neutronic data used in the point kinetics models of TRACE. The authors coupled both codes Serpent and TRACE to calculate the steady-state power and temperature fields. Based on them, the authors have proposed an optimized geometry and flow rates for the reactor. With the optimized design, the results for several reactivity transient scenarios have been presented: step insertion reactivity and reactor over- and undercooled scenarios. The investigated transient scenarios show that the reactor is stable, self-regulating, and can withstand severe conditions.