A cryogenic system design for the International Thermonuclear Experimental Reactor (ITER)

A conceptual design for ITER was completed that involved the development of a suitable cryogenic system for ITER. An overview of the design is reported. Emphasis is on the fact that cryogenics is a mature science, and a system supporting ITER needs can be made from time-proven components without loss of efficiency or reliability. Because of the large size of the ITER cryogenic system, large numbers of compressors and expanders must be used. Very high reliability is assured by arranging these components in parallel banks where servicing of individual components can be done without interruption of operations. This somewhat optimized design supports all the ITER poloidal-field and toroidal-field magnets, and structure cooling requirements. The cryogenic plant compressors are used to force-flow 4.5-K helium to the ITER core. No cold pumps are used. The design satisfies cooldown requirements; reliability requirements; safety requirements, including quench-vent systems; cryogenic-load requirements, including neutron heating, AC heating, thermal radiation, etc.; and the problem of radiation carry-over by cryogens