Effect of water adsorption on tritium release from Li4SiO4

As a ceramic material proposed for tritium breeding in a fusion reactor blanket, lithium orthosilicate (Li4SiO4) is being examined in view of the influence of water uptake on tritium release behavior. In this work, out-of-pile tritium release experiments were performed on Li4SiO4 samples that were transferred and stored under different moisture environments. The water content was measured on the samples that were treated in similar conditions. Effects of water adsorption on the chemical form and temperature of released tritium were investigated. It is found that with the water content increases, the gaseous tritium fraction decreases and the proportion of low-temperature desorption of HTO increases. The results of this study can be used later for engineering and design activities for fusion reactor blankets.