Reformulation of the coupled problem for the simplified closed channel

Daniele Tomatis (1)

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

Several types of nuclear reactors rely on lattices of fuel rods, where the fuel cells constitute the basic units of energy production by the nuclear reactions and of energy removal by the flowing coolant. The coolant channel is physically identified by the volume within adjacent fuel cells, being the fundamental purview of design and safety studies resolving coupled thermo-hydraulic and neutron problems. Although channels are generally opened for optimal heat transfer, its closed version is often in use to describe representative channels in boxed fuel assemblies, or simply faster predictive modelling. This work aims to find a solution to the coupled closed channel problem without solving separately for the different physics in an iterative scheme. The new methodology developed hereafter is demonstrated on a realistic PWR channel with UO$_2$ fuel, and compared against the traditional one based on operator-splitting. The simple model presented in this work serves both research and educational purposes.

Mots clés: Multiphysics coupling; closed channel; PWR

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

Daniele Tomatis. Reformulation of the coupled problem for the simplified closed channel. Annals of Nuclear Energy, 2019, 130, pp.377-387. ⟨10.1016/j.anucene.2019.03.001⟩. ⟨cea-02510805⟩