Welded joints behaviour in high temperature reactors

Welded joints are one of most safety critical locations in a reactor structure. They are often prone to damage after decades of operation and can be considered to be one of the life-limiting factors in the UK's advanced gas cooled reactors. This is because of the complexities involved in a weld including the residuals stress, varying microstructure and their complicated geometry. The aim of this project is to identify the criticality of the stress concentration created at the interface of a welded joint through advanced experimental techniques such as Digital Image Correlation and synchrotron X-ray diffraction. The experimental work is expected to be complemented by finite element simulations to assess the severity of the creep damage accumulated at the weld interface. Critically, the key results are expected to be included in the integrity assessment procedures the engineers use day to day to evaluate the fitness for service of reactor components.