Validation of Popular Models Used in the Analysis of Specific Activity of Primordial Radionuclides in Environmental Samples through 1-D Analytical Modeling

Abstract

A scientific model may be considered agreeable if it conforms to given scientific laws, in addition to being able to procure data that can be replicated to an acceptable level when other time-tested and proven methodologies are applied. For first-time researchers such as graduate students, choosing the right model is not always easy and some may opt for a particular model not because they are assured of its correctness, but because it has been used by peers before them. Such tendencies can inadvertently lead to the propagation of flawed models across generations of researchers. In the field of environmental radioactivity, the “comparison” and “conventional” models are frequently used in the evaluation of specific activity of primordial radionuclides in solids. Through one-dimensional (1-D) analytical modeling, this paper shows that while the conventional model conforms to given scientific laws, the comparison model does not since it wrongly assumes a linear between the intensity of gamma radiation through a solid and mass of the solid. A modified version of the comparison model that corrects for difference in mass between the solids being compared (sample of interest and certified reference material) is advanced.