The effect of red-ox potential of helium purge gas (variously doped with H2, H2O and O2) was examined on tritium release from Li-ceramics (LiAlO2and Li2ZrO3pellets) and on its permeation rate through the 316L stainless steel clads (bare and coated) held at 500°C. Decreasing the H2content from 1000 vpm (reference 'R' gas mixture) to 100 vpm, and substituting H2O for H2, the tritium permeation rate (ca. 1.41010atoms cm-2s-1in R-gas) increases. Tritium inventories in the Li ceramics were increased too. When a strong oxidizing purge (1000 vpm O2added to He containing 100 vpm H2O) was used, a retention time (T) of two days at 400°C was measured for Li2ZrO3. In this oxidizing environment the tritium permeation loss dropped by a factor five for the uncoated capsules while an aluminide coating became a very effective tritium barrier: tritium permeation flux at 550°C fell below the measurable limit. Copyright © 1996 Elsevier Science B.V. All rights reserved.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics
- Nuclear Energy and Engineering
- Materials Science(all)