A method for determining uranium content directly for uranium-bearing ore-body based on quantitative analysis for spectral shape difference

Uranium content can be determined directly based on 234mPa, 1.001 MeV, weak characteristic energy peak measured by HPGe detector spectrometer for uranium-bearing ore-body. However, scintillation spectrometer can't measure the fine structure of gamma spectrum from uranium-bearing ore-body, and the spectrum measured don't show the characteristic peaks which are directly related to uranium. Therefore, a technique which can be used to extract the weak information effectively to determine uranium content directly is needed to study. The present work measures a series of hard rock radionuclide-bearing ore-body using 320CR model portable NaI (Tl) spectrometer, analyzes quantitatively shape difference within the energy windows for the spectra which are collected at centre point of these ore-body model respectively. It determines uranium contents directly using linear regression relative analysis based on 234mPa, 1.001 MeV and 0.734 MeV whose photons emission intensity is lower, and gets good results, respectively. The results meet the requirement that the relative error of uranium content over 500 ppm is less than 10.0% for hard rock ore-body, and the maximal error of main radionuclide content is 9.9%. (authors)