Design, analysis and manufacturing of electrical strap for enhanced first wall panel

Abstract The JSC NIKIET is responsible for the manufacture of the ITER Enhanced Heat Flux (EHF) First Wall (FW) beam, the fingers bodies, the mechanical attachment system and electrical connection system of the FW panel to the shield block (SB). The Electrical strap (ES) is located on the FW rear surface and used for providing current through the FW to the SB and further to the Vacuum Vessel with a goal to reduce the current loops and consequently to decrease the electromagnetic loads acting on the FW during plasma disruption. The NIKIET specialists developed the new design of the electrical strap which has been implemented into the FW design. Electrical discharge machine (EDM) cutting is used for performing the 1.2 mm thickness lamellas in the solid blank. This ES design has been approved by IO. The transient thermal analysis results show that temperature of ES is lower than 300°С for Inductive I operation mode and does not exceed allowable one. The fatigue strength criteria are satisfied for all the considered critical points of ES lamellas. Also the technological validation of ES manufacturing process has been successfully completed and full scale ES mock ups have been manufactured. This paper presents the design description of the EHF FW ES and FW bimetallic pedestal, results of thermal and structural analyses and first experience of mock up manufacturing that were performed by JSC NIKIET specialists in 2015.