Spatial dynamics of MSRE

The paper report about spatial dynamics studies of the Molten Salt Reactors (MSR). MSR is one of the concepts considered within the 'Generation IV International Forum'. The graphite-moderated channel type MSR based on the previous Oak Ridge National Laboratory (ORNL) research is considered.
The physical models and numerical solution procedures used in the dynamics code DYN3D-MSR are described. The most relevant peculiarities in MSR dynamics are the delayed neutrons precursors drift with the flowing fuel and the direct release of fission energy into the fuel-coolant salt. The code is based on the in-house developed code DYN3D for Light Water Reactor, which solves two-group neutron diffusion equations by the help of a nodal expansion method. The same method for prompt neutron kinetics is used in DYN3D-MSR, but the appropriate models for the delayed neutrons and for the thermal-hydraulic have been integrated.
The code has been validated against experimental data gained from the Molten Salt Reactor Experiment (MSRE), performed in the ORNL. After successful validation, the code DYN3D-MSR was applied to the analysis of several hypothetical transients typical for liquid fuel systems. Particularly, a prompt reactivity insertion modeling a control rod ejection accident was analyzed. By performing these analyses, the DYN3D-MSR code has been shown to be an effective tool for MSR dynamics studies.