Mechanical Analysis of the JT-60SA TF Coils

The mission of the JT-60SA Tokamak, which will be built in Japan, is to contribute to the early realization of fusion energy in support and supplement of the ITER program. The JT-60SA project is part of the broader approach for fusion energy. In 2008, due to a design change of the TF cross section, and following the redefinition of the global JT-60SA features, mechanical analyses were redone. The first 2D and 3D mechanical analyses were performed on the current TF design, providing useful information on the pros and cons of the new design. For the 2D analysis, the critical area of the inner leg cross section in the location of the equatorial plane was meshed to study the effect of in plane loads. The analysis includes checking the peak field applied to the conductors and the stress on each of the components of the winding pack cross section, in particular in the insulation which is a critical component. The stress in winding pack cross section is due to the accumulation of cool down strain, "in plane" Lorentz forces and to the quench pressure. Both magnetic and mechanical analyses are performed with the ANSYS V11.0 code. In this paper, we present the main steps of the 2D and 3D FEM calculations which were developed by CEA and used in the following analyses. Associated statements concerning possible TF design optimization with respect to cost, feasibility or risk are also presented.