The thermal conductivity of plasma-facing materials (PFM) exposed to intense radiation is a critical concern for the reliable usage of materials in fusion reactors. However, limited research has been performed regarding the thermal conductivity of structures that rapidly change in a short time during collision cascade processes under irradiation. In this study, we employed the tight-binding (TB) method to investigate the electronic thermal conductivity ( \(\kappa _{\text {e}}\) ) of tungsten-based systems during various cascading processes. We found that \(\kappa _{\text {e}}\) values sharply decrease within the initial 0.3 picoseconds and then partially recover at a slow pace; this is closely linked to the evolution of defects and microstructural distortions. The increase in the initial kinetic energy of the primary knock-on atom and the presence of a high concentration of hydrogen atoms further decrease the \(\kappa _{\text {e}}\) values. Conversely, higher temperatures have a significant positive effect on \(\kappa _{\text {e}}\) . Furthermore, the presence of a grain boundary \(\sum 5\left[ 001 \right] \left( 130 \right)\) substantially reduces \(\kappa _{\text {e}}\) , whereas the absorption effect of point defects by the grain boundary has little influence on \(\kappa _{\text {e}}\) during cascades. Our findings provide a theoretical basis for evaluating changes in the thermal conductivity performance of PFMs during their usage in nuclear fusion reactors.
