Anisotropic small angle neutron scattering analysis of thermally aged reactor-vessel materials

Abstract

Neutron radiation and high working temperatures induce important changes in the microstructure of metallic components of nuclear reactors. These changes result in weakening of the mechanical properties, which is the primary interest in the safety and lifetime management of nuclear installations. In order to follow up the microstructural changes, separately due to radiation and high temperature, first we measured thermally aged steel samples. The observed anisotropic scattering was fitted by a 2D model. We found that the microstructure of aged metals shows a strong dependence on the industrial treatment quality and also on the sampling.