PNNL

Abstract

This chapter presents an overview of the conditions that structural materials being developed for fusion power reactor applications would encounter. We begin by briefly describing the relevant plasma physics conditions that dictate the fusion environment, which determines the loads driving microstructure evolution of fusion structural alloys. The fundamentals of radiation damage in the fusion environment are discussed, but the reader is referred to a much more detailed treatment of this topic given in Chapter 5. Our intent is to highlight the most important degradation mechanisms operating in the fusion environment. We compare and contrast the fusion environment with that found in existing and proposed advanced fission energy systems, highlighting in particular the role that gaseous and solid transmutation products have on property evolution. The majority of the chapter is devoted to a presentation of the principal structural material choices for major subsystems of a fusion power reactor such as the first-wall/blanket, divertor, and vacuum vessel. Our aim is to highlight the essential features of the material choices for each subsystem, and not to delve into the details, since later chapters address each class of structural material in greater depth. The emphasis is on the implication of the environment to the basic physical and mechanical properties requirements of these materials and challenges they face specific to the fusion environment.