INTERNATIONAL STANDARD FOR DESIGN BASIS THREAT (DBT)

A Design Basis Threat (DBT) has been used by the United States since the 1970s as the basis for the design and evaluation of a nuclear facility’s physical protection system and as a standard for comparison as the threat changes. Internationally, there are two approaches to a State’s use of the DBT. The differences lie in where, within the DBT development process, the aspect of “risk” is considered. This difference was evident during discussions among physical protection experts and regulators from France, Germany, the United Kingdom, the United States, and the International Atomic Energy Agency (IAEA). Establishing a DBT is recommended in the IAEA’s Information Circular 225, Revision 4 (Corrected), The Physical Protection of Nuclear Material and Nuclear Facilities (INFCIRC/225/Rev.4.) In 2000, a significant milestone in the international use of the DBT was achieved when representatives from the aforementioned States met, under the coordination of the IAEA, and created an “international standard model” for the development and implementation of the DBT. While Sandia National Laboratories developed the original DBT workshop, that model was based on processes used by the U.S. Department of Energy (DOE) and the U.S. Nuclear Regulatory Commission (NRC). The IAEA desired an international approach for a DBT workshop that could be offered to all Member States. This paper presents a summary of the international version of the workshop on how to create and implement a Design Basis Threat. The paper describes how a DBT may be created within a State, and where, within the process of developing and using the DBT, the element of “risk” is accommodated. Each State may, of course, choose to modify their use of the DBT to better fit their culture, the technical resources of their facilities and authorities, and their regulatory frameworks.