Methodology to identify appropriate options to manage tritiated waste

Highlights: • Fusion devices including ITER will generate tritiated waste. • An interim storage period up to 50 years is the reference solution for tritiated radwaste management. • Alternative strategies or additional processing options have to be sought for highly tritiated waste requiring an interim storage period longer than 50 years. • Defining the BAT for reduction of tritium inventory is relevant to identify ahead of time the studies to be launched and the actions to ensure a route. - Abstract: Fusion facilities will use tritium as a part of fuel. As a consequence, most of waste is expected to be contaminated with tritium and specific waste management strategies need to be developed taking into account physical and chemical properties of tritium. In France, the reference strategy for waste exceeding acceptance limits for disposal due to its tritium inventory is an interim storage period up to 50 years, corresponding approximately to detritiation factor of 16 due to radioactive decay. This article is mainly focused on the most tritiated categories of waste that would require an interim storage period longer than 50 years. Alternative strategies or additional processing options have been sought for these categories and the article defines methodology of identification of the Best Available Technique (BAT) for reduction of tritium inventory in the waste. Furthermore, the methodology is demonstrated on the case of purely tritiated metallic waste made from stainless steel. The methodology has been divided into three main steps: 1) Identification of the most relevant detritiation techniques; 2) Comparative analysis; and 3) Economical assessment. In order to simplify the first step, a software tool has been developed by CEA and its main features are described in this article. The results given by this tool are then analysed in the second step, which takes into account several non-economic criteria. Results of the comparative analysis show that detritiation of purely tritiated metallic waste made from stainless steel appears to be very attractive, allowing a significant reduction of interim storage duration before disposal in a surface repository. The last step, briefly described in this article, is ongoing and will economically assess the results from the previous steps.