Stress analysis of a double-wall vacuum vessel for ITER

The preliminary structural analyses performed in support of the design of the vacuum vessel for the International Thermonuclear Experimental Reactor (ITER) are described. A thin, double-wall, all-welded structure is the proposed design concept analyzed. The results of the static stress analysis indicate the adequacy of such a structure. The effects of the proposed high-aspect-ratio design configuration on loading and stresses are also discussed. It is concluded that the thin-wall `sandwich´ structure is a feasible alternative to the ITER baseline thick-wall design. The vacuum vessel could be easily cooled and operated with a reasonable factor of safety during a plasma disruption. Further development and design could easily eliminate any problem areas or stress concentrations remaining in the vacuum vessel design. The analysis of the HARD (high-aspect-ratio design) configuration revealed some changes in load distribution and magnitude, reflected in lower stresses than in the ITER CDA design