A structural description of the evolution of stakeholders and risk communication in the Department of Energy's defense nuclear facilities: Historical perspective, major stakeholders, and external events.

Regulators and policymakers are routinely challenged with explaining complex concepts concerning risk. Part of the challenge is helping external and internal stakeholders to understand the context behind risk-related information and decisions. This paper will describe the historical evolution of the safety and regulatory framework for an important category in the nuclear industry-defense nuclear facilities owned and operated by the US Department of Energy. In parallel with describing this evolution, three major events which occurred external to the complex of defense nuclear facilities will be summarized, and their impact on the maturation of the Department's safety and regulatory framework will be discussed. Finally, integrated with these two threads of discussion will be a chronicle of the changing set of involved organizations and the expanding set of external stakeholders involved in risk decisions-and therefore, the risk communications ecosystem surrounding defense nuclear facilities. It will be noted that this system was once describable as a classic "iron triangle," but now has progressed to a complex network of federal and state organizations, numerous congressional committees, and expanding sets of external stakeholders. It is hoped that a comprehensive discussion of the context of risk assessment in the defense nuclear facilities complex-addressing historical insights, organizational evolution, and the maturing structure of regulation-will provide enhanced opportunities for building trust and understanding in this complex environment.