The life of modern power generating plant is limited by the high temperature performance of the materials from which it is constructed. The drive for longer operating lives, and higher operating temperatures to raise thermal efficiency, is emphasising the need to understand the role of creep cavitation damage in determining the in-service performance of structural components. One of the challenges currently faced by the nuclear utility EDF Energy is the need to predict, with high certainty, the life-time of ageing plant operating in the creep regime. This requires understanding the underlying physics and micro-mechanisms contributing to creep damage development. The object of the proposed SANS experiment is to measure the degree of cavitation as a function of creep strain using sample discs cut from a single ‘waisted’ creep specimen made from 316H steel with no service history.