Thermomechanical Performance of the EU TBMs Under a Typical ITER Transient

AbstractSix different breeding blanket concepts will be tested in ITER under the form of six different Test Blanket Modules (TBMs). In the frame of the activities of the European TBM Consortium of Associates the Helium Cooled Pebble Bed (HCPB-TBM) and the Helium Cooled Lithium Lead (HCLL) Test Blanket Modules are developed in Karlsruhe Institute of Technology (KIT) and in CEA Saclay respectively. For each EU TBM concept, four different TBMs will be installed into one dedicated ITER equatorial port and tested during different test campaigns. The main goal of the ITER TBM program is providing DEMO relevant experimental data for the three main functions of a blanket module of a future fusion reactor, namely removing heat, breeding tritium and shielding sensitive components from radiation.The two EU TBMs share a common external structure (the so called TBM box) while featuring a different internal design of the Breeder Units (BUs), reflecting the different breeding concept. The preliminary design assessment of the two TBMs boxes is based on nuclear analyses and on the evaluation of the power produced in the BU and deposed on the TBM box structures. The preliminary thermomechanical designs have been presented and are based on steady state analyses.The TBMs will work under ITER loads, i.e. cyclic loads defined by the typical ITER pulses. Transient thermal and mechanical analyses of the two EU TBMs under a typical ITER pulse are presented in this paper, identifying the main design issues related to: structural behavior of the TBM box, codes and standard rules for assessing the TBM box integrity, TBM operational domain and related DEMO relevancy of the experimental campaign. Solutions to improve the weak structural points of the present designs are proposed, identifying the missing rules and the modelling development needs.