1. A nondestructive examining method for detecting and characterizing anomalies in radioactively-contaminated structures comprising: placing a gamma radiation detector in proximity to a surface of a structure to be examined, said detector including a radiation-proof housing with a beam slit therein for conducting gamma radiation from only a very small volume of material to said detector, said detector further including conversion means coupled thereto to convert said radiation to electrical signals; scanning said surface while maintaining said detector in proximity to said surface; measuring and recording said gamma radiation emitted by said structure at a plurality of points about said structure and at various angles relative to the surface, the measuring of gamma radiation including measuring at each point and angle the general background radiation and the radiation due to the inside surface contamination and crack contamination and further measuring and recording a location of said housing relative to a predetermined starting point on said structure for each of said plurality of points wherein gamma radiation is measured, and pairing said measurement locations with said gamma radiation measurements, such that a plurality of data sets, comprising positional coordinates paired with radiation level values are generated; and comparing the amount of radiation detected at each point and angle with the amount detected at each preceding point and angle along each scan direction, such that a graphical representation, including depth, of the anomaly may be developed at each scan location.