Speaker
Description
The European Roadmap to the realisation of fusion energy, carried out by the EUROfusion
consortium, considers the stellarator concept as a possible long-term alternative to a tokamak fusion
power plant. To this purpose a pivotal issue is the design of a helical-axis advanced stellarator
(HELIAS) machine equipped with a tritium breeding blanket (BB), considering the achievements
and the design experience acquired in the pre-conceptual design phase of the tokamak DEMO BB.
Therefore, within the framework of EUROfusion WPS2 R&D activity, a research campaign, aimed
at the investigation of the structural behaviour of the HELIAS 5-B BB, has been launched at KIT in
cooperation with University of Palermo. The scope of the research has been the determination of a
preliminary BB segmentation scheme able to ensure, under the assumed loading conditions, that no
overlapping may occur among the blanket regions. To this purpose, the Helium-Cooled Pebble Bed
(HCPB) and the Water-Cooled Lithium Lead (WCLL) BB concepts, presently considered for the
DEMO tokamak fusion reactor, have been taken into account.
A 3D CAD model of a HELIAS 5-B torus sector has been adopted, focussing attention on its far end
regions, namely the triangular and bean shape regions. Due to the early stage of the HELIAS 5-B BB
R&D activities, the considered CAD model includes homogenized blanket modules without internal
details. Hence, in order to simulate the features of the HCPB and WCLL BB concepts, equivalent
material properties have been purposely calculated and assumed. Moreover, proper nominal steady
state loading scenarios, based on the DEMO HCPB and WCLL thermomechanical analyses, have
been taken into account.
A theoretical-numerical approach, based on the Finite Element Method (FEM), has been followed
and the qualified ANSYS v. 18.0 commercial FEM code has been adopted. The obtained results are
herewith presented and critically discussed.
