Patent Number: 
Section: abstract

A method of assaying potentially radioactive material comprises selecting a plurality of samples from a material mass on a site (200). In a sequence of steps (104, 106, 108, 110, 112), an activity measurement based on a gross count of each of the samples (212) in the plurality of samples is performed on the site (200), and the activity measurement is compared with one or more activity thresholds in order to categorize the radioactive material for disposal purposes. The threshold(s) and/or activity measurement are based on an assumed parameter set. In a further step (114), sample x from every y of the plurality of samples is selected, where x<y, and a spectroscopic measurement of the emitted radiation from the sample x is performed on the same site (200). In a further step (116), it is automatically determined whether the spectroscopic measurement corroborates the assumed parameter set before the y samples leave the site (200) for disposal purposes.