Code for nuclear materials

Neutron irradiation can induce significant changes in the physical and mechanical properties of nuclear materials in reactors. These changes result from the interaction of energetic particles with atoms in the materials. For instance, neutron irradiation initiates collision cascades, which produce point defects in materials. These point defects migrate, react, nucleate, and grow, and eventually induce the microstructural and microchemical evolutions in irradiated materials, which change the material properties. To account for all the important material properties and reactor phenomena, it is necessary to develop and utilize multiscale models and simulations to address a wide range of space and timescales, starting with the nucleus, electronic, and atomic structure (angstrom) all the way to the reactor components (meters), and from defect formation (femtoseconds) to the operating characteristic times (months, years). In this chapter, we will briefly introduce these methods and the corresponding codes in the study of radiation in materials.