Simulating HFIR Core Thermal Hydraulics Using 3D-2D Model Coupling

A. Travis[1], K. Ekici[1], J. Freels[2]
[1]The University of Tennessee, Knoxville, TN, USA
[2]Oak Ridge National Laboratory, Oak Ridge, TN, USA

A model utilizing interdimensional variable coupling is presented for simulating the thermal hydraulic interactions of the High Flux Isotope Reactor (HFIR) core at Oak Ridge National Laboratory (ORNL). The model’s domain consists of a three-dimensional fuel plate and a two-dimensional coolant channel slice. In simplifying the coolant channel, the computational cost and solution time are both greatly reduced. In order for the reduced-dimension coolant channel to interact with the explicitly represented fuel plate, however, interdimensional variable coupling must be enacted along all shared boundaries. The primary focus of this paper is in detailing the collection, storage, passage, and application of variables across this interdimensional interface. Comparisons are made showing the general speed-up associated with this simplified coupled model.