Digital Image Correlation (DIC): An Advanced Nondestructive Testing Method for Life Extension of Nuclear Power Plants

A primary focus for the long-term operation of nuclear power plants (NPPs) is the aging of civil structures at the plant. The integrity of the containment building is of primary importance to the continued operation of NPPs. Some degradation mechanisms of concrete manifest themselves via swelling or by other shape deformation of the concrete. The ability to validate that the shape of the concrete is stable is an indication that certain degradation mechanisms are not active. Digital Image Correlation (DIC) is a nondestructive testing (NDT) technique that is non-contact. The use of DIC is a method to precisely determine the change of shape and the change of strain in a structure. This paper describes the technology behind the DIC technique and the use of DIC during a pressure test on the containment vessel at a NPP in the United States. (author)