Numerical modeling of an in-vessel flow limiter using an Immersed Boundary Approach

G. Billo (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

The increasing performance and safety requirements for the third generation of nuclear reactors led to new Research and Development studies. In this context, new innovative systems are designed to prevent or soften potential accidental or incidental situations. For instance, a passive system to postpone the core dewatering, in the case of a Large-Break Loss Of Coolant Accident in Pressurized Water Reactors, has been imagined and patented by CEA. This passive flow limiter is composed of fins which, in accidental behavior (for instance fluid coming out from the vessel due a break on the cold leg), force the creation of a large vortex of fluid and so reduce the flowrate going outflow of the vessel (i.e. postpone the core dewatering). For more information about the background, the interested reader can refer to reference below. Of course, the pressure drop induced by the device (in both nominal and accidental situations) is greatly influenced by the shape of the fins. Thus, in order to optimize its geometry, a fast and robust numerical tool, able to faithfully model the flow limiter, is needed.

Domains: Nuclear Experiment [nucl-ex]; Nuclear Theory [nucl-th]

G. Billo. Numerical modeling of an in-vessel flow limiter using an Immersed Boundary Approach. 44eme Congres National d'Analyse Numerique, May 2018, Cap d'Agde, France. ⟨cea-02339114⟩