distinguish between materials that reflect similar source or production histories, but are derived from disparate sites.

Due to the significant capital costs of the equipment and the specialized expertise of the personnel, work in the field of nuclear forensics has been restricted so far to a handful of national and international laboratories. There are a limited number of specialists who have experience working with interdicted nuclear materials and affiliated evidence. Therefore, a knowledge management system that utilizes information resources relevant to nuclear forensic and attribution signatures, processes, origins, and pathways, and allows subject matter experts to access the right information in order to interpret forensics data and draw appropriate conclusions, is essential. In order to determine the origin, point of diversion of the nuclear material, and those responsible for the unauthorized transfer, close relationships are required between governments who maintain inventories and data of fissile or other radioactive materials. Numerous databases exist in many countries and organizations that could be valuable for the future development and application of nuclear forensics. The contents of many of these databases may never be shared directly, but even the development of a worldwide, “distributed” database would greatly benefit international efforts. Only by sharing information about nuclear processes and materials can participants benefit from collective experience and knowledge to evaluate and prosecute nuclear trafficking cases. By encouraging the participation of those states where nuclear materials originate, the international community of nuclear forensics scientists gain important insights into the material required to deter future acts of nuclear smuggling.

Historically, the terms “nuclear forensics” and “nuclear attribution” have been used interchangeably. Over the past few years, however, nuclear forensics experts have emphasized a distinction between the two terms.

Nuclear attribution is a process to identify the source of nuclear or other radioactive materials used in illegal activities, determine the point-of-origin and routes of transit involving such material, and ultimately contribute to the prosecution of those responsible. Nuclear attribution utilizes many inputs including: 1) results from nuclear forensic sample analyses; 2) understandings of radiochemical signatures and environmental signatures; 3) knowledge of the methods for production of nuclear materials and nuclear weapons development pathway; and 4) information from law enforcement and intelligence sources. Nuclear attribution is the integration of all relevant forms of information about a nuclear smuggling incident into data that can be readily analyzed and interpreted to form the basis of a confident response to the incident. The goal of the attribution process is to answer policy makers’ needs, requirements, and questions in their framework for a given incident.

Nuclear forensics is the analysis of intercepted illicit nuclear or radioactive materials and any associated materials to provide evidence for nuclear attribution. The goal of nuclear forensics analysis is to identify forensic indicators in interdicted nuclear and other radioactive samples or its surrounding environment, e.g., the container or transport vehicle. These indicators arise from known relationships between material characteristics and process history. Thus, nuclear forensics analysis includes the characterization of the material and correlation with production history.