Evaluating environmental sampling data for Safeguards
– principles and advances

Since the inception of using environmental sampling for Safeguards purposes at the IAEA to detect undeclared nuclear activities, the applied analytical techniques, evaluation methods and software have evolved significantly. Also, the number of environmentalsamplesthat are collected each year during inspection activities has been steadily growing. The increase in data quality, quantity and variety presents challenges to the analysts who receive and evaluate these data on an operational basis. This paper gives an overview of the basic principles of environmental sampling and the advances that have been made to increase effectiveness and efficiency of evaluation. This includes the life‐ cycle of an environmental sample, the state‐of‐the‐art methods that are used for analysis as well as the various data types and methods that are used for evaluation. Examples with model data will be presented to demonstrate how multiple types of data can be utilized together to confirm the absence of undeclared activities. Finally, an overview of ongoing and planned improvements is provided.