Method for assessing the uranium content in a borehole using gamma spectrometry and associated device

A system for assessing a uranium content of a region of interest of a subsoil using gamma spectrometry, the region of interest being crossed through by a borehole, the system comprising:

• a spectrometric probe including a scintillator detector;
• an acquisition module connected to the spectrometric probe, the acquisition module being configured to acquire at least one energy spectrum of gamma radiation associated with the region of interest, the energy spectrum comprising at least one low-energy band, one high-energy band, a contribution of a self-attenuation of uranium in the low-energy band being greater than a contribution of a self-attenuation of uranium in the high-energy band;
• and
• an assessment module of the uranium content configured to assess the uranium content of the region of interest using a surface area of the low-energy band, the surface area of the high-energy band of the acquired energy spectrum in the region of interest and at least two calibration coefficients,
• wherein the low-energy band comprises a lower bound and an upper bound, the lower bound being greater than 98 keV so as to avoid a contribution from uranium fluorescence X-ray radiation in the low-energy band.