Simulation of the system dynamics for the molten salt reactor experiment using modified trace

The aim of this work is to use a modified version of TRACE for a preliminary study of a molten salt reactor (MSR) system behavior for the steady-state, transient and accidental conditions so as to demonstrate the suitability of the TRACE code for MSR simulation. To this end the analysis and results from the MSRE (Molten Salt Reactor Experiment) were used as a reference case. The basic approach of this work is to couple the 1D thermal-hydraulic model for 3 loops and the 0D neutronic dynamics (point-kinetic model), which was solved by the ODEsolver built by "Control Blocks" offered in TRACE. Additionally, new working fluids, namely the molten salts, were added into the source code of TRACE. Most results of the simulations show good agreement with the ORNL reports as well as the previous study in recent years and the errors were predictable and in an acceptable range. Therefore, the necessary code modification of TRACE appears to be successful and will be refined further in order to investigate new MSR designs, such as MSFR¹ and DFR².