Thermal and structural analysis of the ITER ELM coils

A thermal and structural analysis of the ELM Coil design for ITER is presented. The ELM Coils are constructed using a jacketed mineral insulated conductor of CuCrZr, MgO and Inconel 625, rigidly mounted to the vacuum vessel inner shell, behind the Blanket Modules. Since the coils are not designed to be remotely maintained, a major issue is demonstrating the structural integrity against fatigue and crack propagation over an estimated 100 million cycles arising from operation at 5 hz in a high magnetic field. The temperature rises from ohmic and nuclear heating produce mean thermal stresses that further limit the allowable alternating stresses. Thermal growth also imparts large forces which must be reacted by the Vacuum Vessel. This paper presents the analysis and results with particular attention to the design criteria which is unique to the In-Vessel Coils.