Oxidation performance test of detritiation system under existence of SF

Kobayashi, Kazuhiro; Miura, Hidenori*; Hayashi, Takumi; Hoshi, Shuichi; Yamanishi, Toshihiko

The tritium released in the building is removed by Atmosphere Detritiation System (ADS), where the tritium is oxidized by catalysts and is removed as water. Special gas of SF is used as an electric insulation gas in ITER, and is expected to be released in an accident such as fire. Although SF has the potential as a catalyst poison, the performance of ADS with the existence of SF has not been confirmed yet. Therefore, to study the effect of SF, the performance tests of ADS was carried out with air containing 1% of hydrogen, 1% of methane and 1% of SF. The SF gas was notably decomposed in the case of the catalyst temperature higher than 673 K. In addition, a part of the water produced by the 473 K catalyst was reduced to hydrogen due to the reaction with the decomposed gas in SF. Consequently, the detritiation factor of ADS was decreased to less than 50 from 1000 of its initial value.