Analyzing effects of volumetric expansion of uranium during hydrogen absorption

The effects of the volumetric expansion of uranium due to hydride formation during hydrogen absorption are examined numerically. To assess the effects of the volume changes, a three-dimensional transient metal hydride model is applied to multiple computational domains, i.e., generated as a function of the H/M atomic ratio during hydrogen absorption. The numerical simulations are carried out with or without considering the volume change effect. The simulation results clearly show that a higher temperature rise and slower hydrogen absorption reaction are predicted when the volumetric expansion of uranium hydride is taken into consideration in the model simulations. The comparison results highlight that neglecting the volumetric expansion of metal hydride during hydrogen absorption can lead to an overestimation of the hydrogen charging performance.