A tritium removal system (TRS) has been designed and installed. The TRS can remove tritium leaked into a workspace (100 m3). The tritium removal process in the TRS is a wet method in which leaked tritium compounds are oxidized to tritiated water by a catalyst, and the tritiated water is captured by a molecular sieve bed. The tritium removal performance (TRP) of the TRS was evaluated using H2 and CH4. The TRP is expressed by the relationship between the tritium oxidation efficiency of the catalyst bed and the water-capturing efficiency of the molecular sieve bed. The oxidation efficiency of CH4 increased with increasing the catalyst temperature, and it reached to 0.75 around 280°C. The water-capturing efficiency was found to be 0.97 during the operation.

The relationship between the oxidation efficiency and the water-capturing efficiency was reconstructed to chart and evaluate the tritium removal time. The chart evaluating the TRP of the TRS satisfied the design requirements. The design and evaluation method of this TRS can be applied to other TRSs using the wet method.