X-ray diffraction studies of irradiation damage in zirconium alloys

by Dr Rhys Thomas (University of Manchester)




Zirconium alloys are widely used by the nuclear industry as a structural and clad material for use in power reactors. The integrity of these components is crucial for efficient and safe generation of power. During operation, neutron irradiation causes the displacement of atoms, the production of point defects, self-interstitials and vacancies and eventually dislocation loops. This process leads to deleterious effect such as dimensional instability and embrittlement as well as accelerated aqueous corrosion.


Traditionally, transmission electron microscopy is used to quantitatively and qualitatively assess this damage, however this can prove challenging, particularly where there is a high density of dislocations or where loops are small. More recently, analysis of irradiation damage using x-ray diffraction (XRD) line profile analysis (LPA) has proven to be a powerful complementary technique, which samples a comparatively large volume and is not subject to the subjectivity of image analysis. Using a synchrotron opens up the possibility of using more novel techniques, such as microbeam XRD and grain resolved dislocation density analysis. These are particularly useful when looking at materials irradiated with protons, where the damage is variable as a function of depth.


This talk will give a brief introduction to irradiation damage in zirconium and how it can be quantified using line profile analysis. Recent experiments aimed at characterising irradiation damage as a function of dose in proton irradiated samples, performed at the DESY synchrotron, will be discussed. Preliminary results from a grain resolved diffraction experiment will be presented and the future outlook for the field summarised.