Effects of Operational Changes on Safeguards Applications for Enrichment Plants

Development of a safeguards approach that incorporates nondestructive assay (NDA) measurement techniques is dependent upon many operating conditions for a particular facility. Ambient background conditions, in-process inventory, static inventory, and plant design are just a few of the issues that impact development of a measurement method designed to detect target quantities of special nuclear material. Studies have been conducted at various enrichment facilities that demonstrate the necessity for the development of a safeguards approach unique to a specific facility. Additional methods are developed or existing techniques are adapted as the process, design or capacity of the facility being inspected changes. Nondestructive assay experts from the Portsmouth Gaseous Diffusion Plant Applied Nuclear Technology section and the Oak Ridge National Laboratory (ORNL) Joint Center for International Threat Reduction (JCITR) have been involved in the development and implementation of various measurement methods sponsored by the Department of Energy / National Nuclear Security Administration (DOE/NNSA). These methods have been integrated into comprehensive safeguards approaches for uranium enrichment facilities. The measurement methods and hardware utilized must meet the technical requirements for the inspection agency while minimizing any impact on plant operations. Because the conditions at uranium enrichment facilities change with plant operating parameters, these changes must be taken into account during inspections. This paper evaluates the impact of operational changes on NDA measurement methods developed for uranium enrichment facilities.