In contrast to ITER a DEMO Reactor needs large blanket segments (5 per sector) with a thickness of > 1m, which have to be removed through a vertical upper port. Due to the fact that these blanket segments may not be drained (liquid LiPb) or in case of solid Pb as neutron multiplier cannot be drained each has a weight of 160 to 180 tones. In comparison to ITER the contamination potential is significantly larger when considering radioactive dust and Tritium. This is true for the inside of the tokamak and thus for the volume connected to the open port (Cask). However, also in contrast to ITER the activation of the blankets and thus the after heat as well as the amount of Tritium inside the components are also significantly higher. Therefore, the outgassing of Tritium during transport to the Hot Cell (Active Maintenance Facility – AMF) is much higher than in ITER. The sealing of the contamination control door (CCD) by rubber seals is not sufficient to guarantee no diffusion of Tritium to the external environment of the transport cask. Therefore, we need not only a cask-based handling system but we need a secondary containment structure which prevents contamination to spread throughout the tokamak building. In September 2020 a small team (3 to 4 persons including myself) were asked to look into this problem because no good solution has been found to this date. Due to manpower problems the work was performed on and off and in total in less than one year. In this presentation the considerations and the design solutions for a RH system for blanket segments will be presented.
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