Californium-252 in-situ activation and photon detection techniques for uranium ore deposit evaluation

Four different techniques are evaluated for borehole analysis of uranium and thorium ores. Methods involving (1) detection of fission-product photons following 252Cf activation; (2) detection of low-energy uranium and thorium gamma rays; (3) direct measurement of the 1001-keV photon from 234Pasup(m), a progeny of 238U; and (4) isotopic excitation X-ray fluorescence spectroscopy are evaluated. The first two techniques are found too unsuitable for most low-grade ores. The third is found to be suitable for the in-situ analysis of uranium ores only, and the fourth method is shown to be a superior, cost effective method for both uranium and thorium ore analysis. (author)