Technical Papers and Presentations

Modernization of the High Flux Isotope Reactor (HFIR) thermal-hydraulic (TH) design and safety analysis capability is an important step in preparation for the conversion of the HFIR core from a high enriched Uranium (HEU) fuel to a low enriched Uranium (LEU) fuel. Currently, an important part of the HFIR TH analysis is based on the legacy Steady State Heat Transfer Code (SSHTC). The SSHTC is a One-Dimensional heat transfer numerical code that utilizes Nusselt number correlations to bound the quantity of heat transferred to the coolant from the HFIR fuel plate clad surface during the convection process. The multi-dimensional multiphysics capabilities of the COMSOL environment allow the analyst to relax the number and magnitude of conservatisms imposed on the TH nuclear system by the SSHTC. To this end, it was necessary to first demonstrate that COMSOL could indeed reproduce the results of the SSHTC given the same inputs. The results of this endeavor indicate that COMSOL does indeed produce similar results to the SSHTC.