The effects of shielding on Non-Destructive Analysis (NDA) and the use of Small-angle Compton scattering to overcome those effects

The use of passive Non-Destructive Analysis (NDA) equipment and techniques are very beneficial tools in the nuclear industry that have a plethora of applications and advantages over destructive or more invasive measurement methods. Of course, NDA techniques also have many limitations including dealing with many unknown parameters, overcoming the effects of gamma ray shielding, and the reliance on making many gross assumptions in the analysis of non-destructively acquired data. These limitations can lead to biased results or extremely difficult analysis which often introduces inaccurate conclusions and/or high levels of uncertainty.

This thesis paper will focus on specific NDA equipment and analysis techniques and discuss how they work, what their advantages are, what their disadvantages are, and some critically important real-world applications and uses of these NDA measurement techniques. The main focus of this discussion will explore great details about the theory, validation, and application of a newly developed NDA measurement technique called “Small-angle Compton scattering” which is a naturally occurring phenomenon in gamma energy spectrum that occurs when gamma rays are shielded by materials directly between a radioactive source and a detector. This paper will explain how this phenomenon can be observed and interpreted to give critical information about the effects of attenuation on a radioactive source, help improve non-destructive analysis techniques, and improve the overall results of difficult yet common measurement conditions of radioactive materials, principally Uranium-235 (U-235).