Thermo-structural analysis of target assembly and back plate in the IFMIF/EVEDA lithium test loop

IFMIF is an accelerator-based intense neutron source for testing candidate materials for fusion reactors. The Engineering Validation and Engineering Design Activities (EVEDA) of IFMIF are in progress under the Broader Approach Agreement. In the EVEDA Li test loop, two types of target assemblies, “an integrated type target assembly without a back plate”, made of SUS316L, and “a target assembly with replaceable bayonet back plate”, made of F82H steel, will be evaluated. For these target assemblies, thermal stresses were evaluated using the ABAQUS code. As the permitted stress, the values of yield strengths at 300 °C were used. In the case of the integrated target assembly, the maximum thermal stress was below the allowed stress (164 MPa). However, in the case of the target assembly with the bayonet back plate, thermal insulation around the back plate should be necessary to reduce the thermal stress below the allowed value (455 MPa).