Methods for the In situ Measurement of Radionuclides in Soil.

摘要

The use of germanium crystal (Ge) spectrometers for the in situ detection and quantification of surface deposited and volume distributed radionuclides presents six distinct advantages over other methods. The advantages are (1) better sensitivity than laboratory Ge spectrometers, (2) counting times reduced by a factor of 30--50 for equivalent statistical accuracy in the laboratory, (3) much larger areas or masses of soil can be evaluated with more meaningful extrapolations, (4) ''hot spots'' or concentrations of high radioactivity can be identified and immediately investigated, (5) hypotheses can be readily tested, and (6) sampling for materials to be returned to the laboratory can be carried out more logically. A mathematical method for quantifying soil activity on the basis of field spectrometric measurements, a calibration procedure, and a generalized computer code for application to a variety of detector geometries and source distributions are also presented. 16 refs., 6 figs., 5 tabs.