Recent in-house developments in theoretical modelling of ultrasonic inspection

Over the years British Energy, in collaboration with British Nuclear Group, has developed an extensive suite of computer codes for modelling the ultrasonic inspection of smooth and rough planar defects in ferritic steel components. The models are used to help in the design of new inspections, and to provide evidence on detection capability when writing a technical justification for inspection qualification purposes. This paper provides an update on the current status of these models, including their experimental validation. It also briefly describes some recent developments in modelling the scattering from rough defects, allowing for the effects of fine-scale roughness, and in modelling the inspection of surface-breaking cracks using the corner effect. In both cases, experimental validation plays an important role.

A recent application of the models, in the technical justification of an automated ultrasonic in-service inspection of a pressuriser weld at Sizewell B Power Station, is also described.