|The irradiation damage in the structure of a spallation target, i.e., atomic displacement and Spallation Elements (SE) production, is specific to spallation and will change the in-service properties. This proposal addresses the effects of
(i) Spallation Elements (SE) on microstructure and mechanical properties before irradiation,
(ii) SE production on microstructure and mechanical properties via ion implantation,
(iii) fast neutron irradiation on mechanical properties to complement the existing data,
(iv) irradiation in mixed neutron-proton prototypical spectrum on mechanical properties and microstructure. In addition modelling is dedicated to irradiation damage characterisation, hardening prediction and segregated boundary cohesion energy computation. The main outputs are a validated database on tensile, Charpy, fracture toughness and the selection of reference steel, for design studies.