Investigation of Thermal Contact Gas Gap Conductance Using COMSOL Multiphysics®

J. D. Freels[1], P. K. Jain[1], C. J. Hurt[2]
[1]Oak Ridge National Laboratory, Oak Ridge, TN, USA
[2]The University of Tennessee, Knoxville, TN, USA
Published in 2013

Our safety analysis group in the Research Reactors Division of Oak Ridge National Laboratory supports a project to investigate the production of Pu-238 isotope for missions of deep space travel in the High Flux Research Reactor. COMSOL Multiphysics® has been used to support this activity in the past, and we have successfully installed and irradiated three different target designs. The gas-gap conductance is responsible for the dominating effect on the temperature change within the irradiated target assembly being analyzed. The maximum temperature is the limiting criteria for how much material can be irradiated, and what location within the HFIR the target can be placed and receive maximum flux and isotope production. This paper documents our comparison between established methods of accounting for the gas-gap conductance.