Evaluation of Hybrid K-edge Densitometry for Pyroprocessing Material Assay

摘要

The advent of electrochemical reprocessing methods (i.e., pyroprocessing) for spent nuclear fuel processing necessitates the development of new safeguards measurement methods and a determination of their effectiveness. A method for performing pyroprocessing material accountancy is Hybrid K-edge Densitometry (HKED), which uses tuned photon transmission and characteristic x-ray emission to characterize the elemental composition of samples of interest. Currendy, HKED has been employed as a safeguards measurement technique to determine the major actinide (plutonium and uranium) content of aqueous spent fuel reprocessing lines. In order to test the feasibility of employing HKED for pyrochemical salt solution assay, a detailed model of a commercially available HKED measurement system was created using MCNP6.1 and employing a mixed variance reduction strategy. Actinide concentrations for aqueous solutions were chosen to match previously completed measurements providing a basis for model validation. This model was used to predict system response to varied concentrations of major and minor actinides in aqueous solutions and pyrochemical salts of eutectic KCl-LiCl.