Sizing of stress corrosion cracking on austenitic stainless piping in a nuclear power plant from eddy current NDT signals

This paper proposes a novel algorithm for the reconstruction of stress corrosion cracking from eddy current testing signals, and reconstructs natural stress corrosion cracking on 8.7mm thick austenitic stainless piping that provided coolant water for a nuclear reactor. The cracks, which were caused by vinyl chloride labels attached to the outer surface of the piping, are modeled as a conductive region, and both the boundary profile and internal conductivity are reconstructed with the algorithm. The reconstructed profiles agree well with the true ones revealed by destructive testing, which confirms the validity of the algorithm and proves that the applicability of the eddy current testing to the sizing of real cracks not only in thin structures such as steam generator tubes but also general structures.