Variations on achieving an effective physical protection system

Physical protection systems should be designed to counter the perceived threat. Regardless of the motivation and composition of adversaries, they can employ only a limited number of tactics, namely, deceit, stealth and/or force. The counter these tactics, physical protection systems employ detection, assessment and delay in several layers. The concept of layered or in-depth protection is incorporated in the IAEA information circular, The Physical Protection of Nuclear Material (INFCIRC/225/Rev.3), which states the Category III material should be stored within an area to which access is controlled, Category II material within a protected area and Category I material in a strong room within an inner area. While the paper provides general guidelines for the design of physical protection systems, it does not address analysis of cost and operational effectiveness. When designing a physical protection system, planners should analyse what level of detection, assessment and delay is best incorporated into each protective layer to achieve the most cost effective and operationally effective integrated system. The paper reviews the tactics of adversaries; considers the effectiveness of detection, assessment, delay and response as a function of the various layers of an in-depth system; and suggests a comparison of the relative cost and operational effectiveness of different combinations of detection, assessment and/or delay in the various layers. (author)