Materials for the nuclear industry

The term "nuclear materials" covers two distinct industrial fields: materials that are conventionally used in industry, generally under thermomechanical conditions similar to those in reactors, and those that are selected for their particular nuclear properties.

Steel, graphite and concrete were used long before the development of the nuclear industry. However, certain particularities induced by nuclear energy, essentially linked to the effects of irradiation, lead to specific behaviors. It is imperative to master these sufficiently to be able to take them into account during design and industrial use.

In the class of materials selected for their nuclear properties, we obviously find fuels, in particular uranium or plutonium for their fission reactions, zirconium-based alloys because of their very high transparency to neutrons, or "absorbing elements" used to control the nuclear reaction, such as alloys containing cadmium or boron compounds. For these materials, the impact of nuclear transmutations could significantly alter their behavior. And let's not forget all the components used for protection or instrumentation (neutron irradiation or electromagnetic flux measurements), for which the choices will be linked to the reactions induced during a given irradiation (absorption, β emission ^– , activation, etc.).

In this article, we will look at the criteria for selecting materials for nuclear applications and at the modifications induced by irradiation during their industrial use. A simplified description of the stresses present in nuclear environments will precede an introduction to the physical mechanisms of irradiation damage, before applying these concepts to the various nuclear materials or environments to be considered.