A method of determining if a radiation spectra comprises radiation corresponding to naturally occurring radiation material sources (NORM), the method including: gathering the radiation spectra; normalizing the gathered spectra by using one or more predefined normalization techniques; energy scaling the normalized spectra by using one or more energy scaling techniques; and determining materials corresponding to each energy reading in the scaled energy spectra for categorizing the determined materials into one or more predefined categories by using one or more classification algorithms.