Experimental durability studies of electrolysis cell materials for a water detritiation system

Iwai, Yasunori; Hiroki, Akihiro; Yagi, Toshiaki*; Tamada, Masao; Yamanishi, Toshihiko

The radiation durability of the solid-polymer-electrolyte (SPE) water electrolyzer composed of the Water Detritiation System (WDS) was investigated. A series of -ray and electron beam irradiation tests of Nafion N117 ion exchange membrane, a key polymer in a SPE electrolyzer, beyond ITER-WDS requirement (530kGy) indicated Nafion N117 has enough radiation durability up to 1600 kGy from the view points of mechanical strength and ion exchange capacity. To keep electrolysis function of a SPE cell up to 530 kGy, we suggest replacing Teflon with polyimide. A series of -ray irradiation test of Kapton polyimide observed no serious damage in strength up to 1500 kGy. Concerning rubber material for O-ring seal, we observed that soaking VITON rubber keeps the constant value of tensile strength up to 1500 kGy. Moreover organic elution was not observed from a soak of VITON. From the viewpoint of stable strength and organic elution, VITON is a first candidate for rubber material.