Fuel relocation in Molten Salt Reactors in a loss of fuel solubility event

Highlights: ► Accident of precipitation in MSR could cause relocation fuel. ► Relocation effect on reactivity coefficients depend relation Molten salt-Graphite-C/MS and channel radius. ► High C/MS and high channel radius make more negative reactivity coefficients. - Abstract: This study considers the consequences of precipitation events in Molten Salt Reactors (MSR). Such events come about as a result of loss of fuel solubility within coolant (FLiBe). It is proposed that the ensuing growth and agglomeration of precipitates may result in relocation (radial stratification) of the fuel along the centerline channel. We assume that in such precipitation events, the fuel solid is not uniformly distributed. This assumption is valid at relatively low Reynolds numbers, where the turbulent stresses are much smaller than the buoyancy forces, a situation which is likely in an MSR. The neutronic impact of such a relocation is analyzed.