A methodology to determine natural radioactivity by γ spectrometry without using calibrated standard samples.

When determining the radioactivity in materials by γ spectra, different processes are involved difficulting the fit. Besides, calibrated standard samples are necessary. In this work we propose a methodology to determine natural radioactivity using simulated γ spectra by Monte Carlo and without the use of calibrated standard samples. We applied this methodology to determine radioactivity of K 40 isotopes from a light salt sample. Then we applied this process in soil samples and the results where compared with the values obtained by an other laboratory. In this comparison our results are on average a 13% smaller.