Modeling of tritium release from ceramic breeder materials by focusing on transport process in breeder grain

The effect of water vapor on the releases of tritium from a lithium silicate was investigated. Out of pile tritium release experiments were conducted using the ceramic breeder irradiated in a research reactor. Tritium was released from the lithium silicate breeder material using a nitrogen sweep gas with 0.1% water vapor. It was found that the addition of water vapor to the sweep gas greatly enhances the release rate of tritium from the ceramic breeder. The results of the tritium release experiment were analyzed using a numerical model of diffusion control. However, the analysis indicates that the assumption of only diffusion control cannot reproduce the experimental results. Thus, the effect of trapping sites was also considered in the model. It was found that the model with the trapping site effect reproduce the experimental tritium release curve.