NGSI Program to Investigate Techniques for the Direct Measurement of Plutonium in Spent LWR Fuels by Non-destructive Assay

The National Nuclear Security Administration’s Next Generation Safeguards Initiative (NGSI) is more than one year into an integrated project to investigate over a dozen nondestructive assay (NDA) techniques to evaluate signatures of spent LWR fuel for the purpose of determining total plutonium content. This multi-year, multi-laboratory program brings together expertise from across the DOE complex and several universities in an integrated approach to evaluate a variety of active and passive techniques. While it is likely that no single NDA technique is, by itself, suitable for determining the total plutonium in a spent assembly, several combinations of two or more techniques do show promise. In this paper, we will provide an overview of the program as a whole, in particular the rationale for focusing on spent fuel assay, highlight progress to date in our modeling and evaluations, introduce initial approaches to technique integration, and describe our path forward in this challenging program.