1. Normal operating conditions

During normal operation, the fuel assembly is subjected to a variety of stresses. We will review the main ones and describe the analytical approach to studying the effects they generate, as well as the technological solutions to the problems posed. We will distinguish between hydraulic, thermal and mechanical stresses exerted on the assembly structure and on the fuel rod.

In addition to these stresses, we need to superimpose the particular effect of irradiation, which results in heating, changes in the physico-chemical characteristics of materials, dimensional modifications of certain components, and changes in material behavior laws. These effects of irradiation are taken into account in studies of the assembly's behavior during its life in the reactor; it is therefore necessary either to carry out evolutionary studies, or to determine the most penalizing conditions...