Studies of surface adsorption on LiAlO/sub 2/

Computational and experimental approaches are being taken to understanding surface adsorption/desorption effects on tritium inventory and release. The computational survey integrates a thermodynamic treatment of surface adsorption and bulk phase effects such as solubility and gas phase composition. The system T/sub 2/O:T/sub 2/:LiAlO/sub 2/ was examined. The calculations indicate that surface adsorption can be expected to contribute most to tritium inventory under the conditions of lower temperatures and higher oxygen activities. Higher temperature and lower oxygen activity favor lower surface inventory. In the experimental work, a high temperature gas chromatograph was constructed in order to measure the H/sub 2/O:H/sub 2/ surface adsorption isotherms and the solubility of hydroxide in LiAlO/sub 2/. Preliminary data indicate that at 478K approximately 15% of the surface is covered for a partial pressure of H/sub 2/O of approximately 52 Pa. Calculated values can be obtained that are in reasonable agreement with this.