Copper alloys used for support units of ITER blanket modules: Compression and tension properties

Four flexible support units are used for each first wall module bracing to the vacuum vessel of ITER. The support unit consists of fastening bolt, flexible cartridge and collar for compensation of thermal expansion. The collar made of copper alloy operates under considerable compression load. The performed structural analysis shows that stresses in the collar exceed the design allowable value specified in ITER Structural Design Criteria for In-Vessel components (SDC-IG) for CuCrZr-IG alloy. The ITER SDC-IC design allowables for CuCrZr-IG alloy were based on tensile data for solution annealed and age material. There is a potential to keep structural integrity if material with higher strength will be used. It is also reasonable to use real compression data for specification of allowable stresses.