The purpose of this work was to explore the feasibility of using the GOTHIC thermal hydraulics software package to model a pressurized conduction cooldown event in the High Temperature Test Facility. To achieve that aim, a model of the facility was constructed in the GOTHIC software and a selection of simulations were run with varying characteristics.
The various scenarios examined the effects of grid sizing, emissivity, facility to model simplifications, and bypass flow on simulation results. An examination of the results showed that the medium grid used in this project was sufficiently fine to capture the phenomena of interest and that those phenomena are insensitive to moderate changes of emissivity in both the core and reactor cavity regions. However, the model was very sensitive to flow distributions due to simplifications made to construct the model in GOTHIC.
Without experimental data to compare with, this study looked to a previous work done on HTTF for comparison. A comparison of showed similarity in several areas but with distinct differences as well. However, until the results of the GOTHIC model can be compared against experimental data, no general conclusions can be made on its level of accuracy.