Alloys which are resistant to damage by irradiation that maintain microstructural stability are enabling to numerous nuclear applications including Gen IV reactors. Elements having reduced activity to irradiation combined as a complex concentration alloy (CCA) also known as high entropy alloys are candidates for nuclear structural applications. Equimolar and near equimolar compositions utilizing the refractory metals as well as Ti, Cr, Fe, and V have been produced in multiple combinations utilizing fusion additive manufacturing and vacuum are melting. The alloy compositions as produced and after variable and multiple heat treatments have been characterized by XRD, SEM, energy dispersive x-ray spectroscopy, hardness and modulus using Vicker’s and nano-indentation. Based on initial screening, select compositions are undergoing irradiation exposure that will be followed by re-characterization to define the resistance of such alloys to irradiation, establishing which alloy compositions can be used in construction for nuclear systems.