EHF FW panel for ITER BM with mechanical attachment of the plasma-facing components

A full-scale prototype of the first wall (FW) panel shall be manufactured in the framework of the Procurement Arrangement between IO ITER and Russian Domestic Agency signed on 13.02.2014 (Leshukov, 2016) [1]. The design of the full-scale prototype was developed based on FW panel #14 type A and comprises the following components: the first wall load-bearing structure (FW beam), plasma facing components (FW fingers) and a central slot insert (CSI) intended to protect the FW beam/FW finger welds against the plasma radiation heat flux. For better maintainability and to enable nondestructive testing of the FW panel components at the final assembly stage, the full-scale prototype was redesigned in 2017, including the substitution of the FW finger/FW beam weld attachment for mechanical attachment. Since the mechanical attachment is under the FW fingers, it does not require protection against the plasma radiation which makes it possible to avoid the use of the CSI in the design and to simplify the FW beam cooling circuit configuration; to be made, the final solution, however requires thermal loads in the FW beam central part to be evaluated for the option with no CSI used. A parametric calculation was performed by JSC NIKIET's specialists for the FW panel design option with the FW fingers attached mechanically to investigate the influence of the slot depth in the FW panel central part on the thermal stress caused by plasma radiation. This paper summarizes the description of the modified FW panel design with the FW finger mechanical attachment, as well as the results of the structure's thermal analysis and structural analysis.