Thermal-structural analysis for ITER in-wall shielding block

In order to verify the design strength of the in-wall shielding (IWS) blocks of the ITER, thermal-structural analyses of one IWS block under vacuum vessel (VV) baking and plasma operation conditions have been respectively performed with finite element (FE) method. Among the complicated operation scenarios of the ITER, two critical types of combined loads required by the load specification of IWS were applied on the shielding block. The stress of the block is judged by American Society of Mechanical Engineers (ASME) criterion. Results show that the structure of this block has enough safety margin, and it also supplies detailed information of the stress distribution in concerned region under certain loads.

► IWS blocks shall withstand various types of mechanical loads including EM loads, inertial loads and thermal loads.
► Due to the complicated geometry, the finite element method is the suitable tool to solve the problem.
► Contact element has been selected to simulate the friction between the different components.
► At baking phase, secondary stresses due to preloading and temperature difference predominate in the total stress.
► At plasma operation phase, secondary stresses due to preloading and thermal loads were deducted from the total stresses.