Material damage evaluation and residual life assessment of primary power plant components using specimens of non-standard dimensions

Obtaining information on the mechanical condition of service exposed primary power plant components can be problematic because of the need to sample significant quantities of material for testing direct from the component. To address this problem, techniques using specimens smaller than the 'conventional' ones described by commonly used test standards have emerged. Several experimental techniques that have been developed and validated with the aim of assessing mechanical condition, particularly from the point of view of fracture toughness, are reviewed. These involve the use of specimens reconstituted from previous tests or of subsize or even miniaturised specimens. The ability of these tests to reproduce data from full sized specimens and their range of applicability is discussed.