Development and verification of a new 3D coupled code for tritium transport in gas and solid based on OpenFOAM

For fusion reactors using deuterium and tritium as fuel, the leakage of tritium poses a threat to the environment and personnel due to its radioactivity. Therefore, tritium transport throughout the operation of fusion reactors is an important factor in evaluating the safety of fusion plants. This work introduces a 3D tritium transport model for tritium in gas and solid phases and develops a coupled transport code based on OpenFOAM. The gas-phase transport model is validated using helium injection tests, with deviation in the steady-state values within +/- 10%. A series of cases are set up to verify the solid-phase transport model. The validation results were compared with analytical value and TMAP, with relative deviation within 1%. Furthermore, reproducing the gas-driven permeation (GDP) experiment and the thermal absorption/desorption experiment of deuterium in beryllium to further validate, with results matching well with experimental values. The all verification and validation results show that the new developed 3D code can capture the transport behaviors of tritium in different scenarios.