Mechanical behavior of Li4SiO4 in a blanket typical geometry

The mechanical behavior of the granular ceramic breeder material is of importance for the integrity of any solid breeder blanket concept. Finite element calculations for blanket relevant conditions are performed using methods from soil mechanics. These account for volume compaction during compression and for shear failure i.e. when particles change their position within the granular lattice. Experimental results for compression of the breeder material in a blanket typical geometry (in a flat bed) are presented. The bed is mechanically compressed in poloidal direction, simulating the stress caused by thermal expansion of the breeder material during the blanket operation. The bed is allowed to expand radially, a fact that is important because radial temperature gradients may cause radial stress profiles in the blanket. The theoretical predictions of finite element calculations using the ABAQUS code are compared with experimental observations. The experiments show a major influence of the mechanical behavior on the filling method of the facility.