Key design integration issues addressed in the EU DEMO pre-concept design phase

European DEMO first wall shaping and limiters design and analysis status

“…The estimated heat load is so large for the UL that it seems to be unavoidable that the tungsten monoblocks would melt/evaporate [6]. In the design the focus is on ensuring the integrity of the heat sink structure in such event, so that the coolant cannot leak into the plasma chamber [5].…”

“…In case of a downward VDE an OLL is being considered to protect the BB. This work is in the early stages [5]. They need to be located just slightly further down from the OMLs offering an opportunity to install/remove these limiters and provide coolant connections also through the equatorial port.…”

“…However, in case of normal and off normal transients the heat flux on the FW can exceed well the above-mentioned limit. The DEMO key design integration issue -1 (KDII-1) is concerned with the performance and feasibility of limiters during these transients [4][5]. The envisaged worst plasma transients are:…”

The EU DEMO equatorial outboard limiter — Design and port integration concept

“…The protection of the first wall (FW) of DEMO, a first of a kind DEMOnstration fusion power plant [1], is one of the key design integration issues [2], [3] in the scope of the Power Plant Physics and Technology (PPPT) department of the EUROfusion Consortium. In order to protect the breeding blankets (BBs) FW from charged particle loads, protection limiters are foreseen [4].…”

“…DEMO poloidal cross-section with inboard-midplane, upper, outboard midplane, and outboard lower limiters shown in red, breeding blanket (grey), divertor (sandy brown), VV and ports (green), TF coils (light blue), central solenoid transformer and poloidal field coils (dark blue), pipes (red, blue and magenta). [3] (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article).…”