(POS-44) Validation of ISOCS Neptunium-237 Content Measurement Using Destructive Analysis

Greg Nutter – Oak Ridge National Laboratory; Laetitia Delmau – Oak Ridge National Laboratory; Susan Smith – Oak Ridge National Laboratory; Luis Castellanos – Oak Ridge National Laboratory; Rachel Hunneke – Oak Ridge National Laboratory

Nondestructive assay using gamma ray emissions to perform quantitative measurements of nuclear material is a common practice in the nuclear industry. The ISOCS (In Situ Object Counting System), a Mirion Technologies product, consisting of a characterized high-purity germanium detector, gamma spectra collection software, and a model of the measurement geometry, can be used to calculate the quantity of each isotope present in situ. Because of the nature of the typical measured items, such as sealed waste containers or material trapped in filters and process equipment, validation of measurement results is difficult. Multiple ISOCS measurements were performed on a piece of nuclear process equipment, a product feed pipe assembly for a rotary kiln containing 237Np. Subsequently, the pipe was cut into sections, and the smaller pieces were also measured using ISOCS. The nuclear material was dissolved, and the corresponding solutions were analyzed by radiochemists at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center to provide validation data for the nondestructive measurement and calculation. This paper will discuss the measurement results from both nondestructive assay and radiochemistry, and the comparative results will be used to benchmark the ISOCS measurement model.