Assessment on electromagnetic force reduction on modular type blanket structure at plasma disruption for the ITER

An electromagnetic (EM) analysis of the ITER blanket system at the plasma disruption has been performed to investigate eddy current and EM force distributions on the blanket modules, especially with the emphasis on the effect of the toroidal slits on the module side surfaces on the EM force reduction at the centered plasma disruption. As the results, the installation of the toroidal slits on the module side surfaces was found to be effective to the EM force reduction on the module, by about 7% for a slit, 16% for 2 slits and 25% for 3 slits, respectively, compared with that on the module structure without the slits. Maximum stress induced at the module attachment edges under the EM forces also decreased by 5% for a slit, 14% for 2 slits and 22% for 3 slits, respectively.