Transient coupled calculations of the Molten Salt Fast Reactor using the Transient Fission Matrix approach
Résumé
In this paper we present transient studies of the Molten Salt Fast Reactor (MSFR). This generation IV reactor
is characterized by a liquid fuel circulating in the core cavity, requiring specific simulation tools. An
innovative neutronic approach called ‘‘Transient Fission Matrix” is used to perform spatial kinetic calculations
with a reduced computational cost through a pre-calculation of the Monte Carlo spatial and temporal
response of the system. Coupled to this neutronic approach, the Computational Fluid Dynamics
code OpenFOAM is used to model the complex flow pattern in the core. An accurate interpolation model
developed to take into account the thermal hydraulics feedback on the neutronics including reactivity
and neutron flux variation is presented. Finally different transient studies of the reactor in normal and
accidental operating conditions are detailed such as reactivity insertion and load following capacities.
The results of these studies illustrate the excellent behavior of the MSFR during such transients.