A methodology to assess the impact of the manufacturing margins of the HCLL-TBM first wall in the design criteria

During manufacturing, nominal fabrication dimensions of the Helium Cooled Lithium Lead (HCLL). Test Blanket Module (TBM) will be machined within certain ranges and these deviations could affect the thermo-hydraulic and mechanical design criteria. In this paper, a generic methodology is presented to assess the impact on the maximum allowable temperature in the FW of 3 geometrical design factors, the distance from the plasma facing side of the first wall (FW) to the cooling channel and the poloidal and radial dimensions of the cooling channel. This methodology is sufficiently generic to be extended to other factors or to other design criteria. It mainly consists in building a surrogate model following saturated fractions of a 3n factorial design (Rechtschaffer factorial design). In that purpose, numerical experiments assuming 10% of deviation with respect to the nominal dimensions have been run using a 3D finite elements thermal model. The exploitation of the surrogate model allows quasi straight fully to assess:(a) able margins for a manufacturing technique (prior to the fabrication of the part). obal effect of the final defects on the manufactured part. urrogate model is to be considered as a straight and useful tool to select a manufacturing process or to reject a manufacture.