Adsorption and Permeation Behavior of Tritium in Vacuum Storage Vessel Materials

Adsorption behaviour of tritium in 316 L stainless steel vacuum storage vessels and gaskets which used for tritium targets storage about 4 years and 20 years was investigated, and the permeation rate of tritium in the stainless steel vessels was analysed as well. The results showed that tritium on the surface of the stainless steel vessels was dozens Bq/cm², and there was about 10⁶ Bq/g tritium in stainless steel and ceramic materials. During thermal desorption to 1 273 K, about 99% tritium released from these materials, and the proportion of HTO in ceramic was more than stainless steel. The permeation rate of storage vessels in summer was about 4 times than that in winter. It indicated that tritium adsorbed on the inner surface of the storage vessels at first, some of it diffused to the matrix and remained in it, others permeate from storage vessels to environment, and the temperature is one of the key factors which affect tritium permeation.