The ultrasonic detection (discrimination from geometrical reflectors) and sizing of intergranular stress corrosion cracks (IGSCC’s) is an essential element in the continued safe operation of nuclear power plants. Unfortunately, these ultrasonic tests are rendered difficult by the complex topography of the cracks, which may include multiple facets and branches which scatter ultrasound in a nearly independent fashion. Thus, the waveforms reflected from such flaws exhibit complex shapes which may not be related to the overall extent of the flaw in a simple fashion.