Nuclear Material Accounting and Control Measurements

Nuclear material accounting and control (NMAC) is the collective set of activities that help to deter and detect unauthorized removal of nuclear material by maintaining and reporting accurate and timely inventories of all nuclear material present. NMAC is used for both nuclear safeguards and nuclear security, though the implementation may differ given the different objectives of the two. The purpose of nuclear safeguards is to detect and deter a State’s clandestine nuclear weapons program. The purpose of nuclear security is to prevent and detect attempts to steal nuclear material by a non-State actor. NMAC protects against both of these very different threats/adversaries. Even though the legal obligations, requirements, and implementation of an NMAC program differ among countries, facilities, and agencies, the basic NMAC principles are the same. This appendix discusses the basic NMAC principles with a focuses on the role of nondestructive assay, general guidance, and best practices related to measurements and measurement control as they relate to an effective NMAC program.