Evaluation of deuterium permeation reduction factor of various coatings deposited on ferritic/martensitic steels for development of tritium permeation barrier

Nakamura, Hirofumi; Isobe, Kanetsugu; Nakamichi, Masaru; Yamanishi, Toshihiko

Tritium permeation reduction performance of various coatings was evaluated by means of deuterium permeation experiment and thermal stress analysis. Several coatings such as amorphous CrPO, plasma sprayed zirconia (ZrO) and gold plating. As the results, ZrO showed relatively good permeation reduction performance about 1/10, and deuterium seems permeate through the grain boundaries or cracks of the ZrO. Improvement such as filling the diffusion path will be effective for further permeation reduction performance. On the other hand, gold plating showed excellent permeation reduction performance around 550 K. Permeation reduction by gold plating would be attributed to low solubility of deuterium in gold. Results of thermal stress analysis were consistent with the results of permeation experiment. Therefore, thermal stress analysis could be an effective method for the selecting permeation reduction coatings prior to the permeation experiment.