On the effect of stiffening plates configuration on the DEMO Water Cooled Lithium Lead Breeding Blanket module thermo-mechanical behaviour

Within the framework of the pre-conceptual design of the EU-DEMO Breeding Blanket (BB) supported by EUROfusion action, results of the research activities carried out in the last years have highlighted that changes in the proposed Water Cooled Lithium Lead (WCLL) BB design have to be considered, especially as to the liquid breeder circulation path within the BB module. Therefore, in view of the definition of a final WCLL BB module layout, a parametric campaign of numerical analyses has been carried out at the University of Palermo in order to assess the impact of different SPs configurations on the module thermo-mechanical performances. To this purpose, attention has been focussed on the WCLL BB Outboard Central Segment and two different concepts have been considered, both based on the use of mixed horizontal (toroidal-radial) and vertical (poloidal-radial) SPs and mainly differing as to the allowed breeder flow path. For each concept, three toroidal-radial cells of the outboard module equatorial region have been considered and the effects of the thickness, pitch and radial length of their SPs on the module thermo-mechanical performances have been investigated under the Over-Pressurization accidental scenario, following an in-box Loss Of Coolant Accident. The study has been carried out following a theoretical-numerical approach based on the Finite Element Method (FEM) and adopting the quoted Abaqus FEM code. The results obtained are herewith reported and critically discussed.