Human behavioral responses to potential hazards are mediated by the beliefs held about those hazards. This holds whether the "behavior" under consideration is the provision of advice about the hazard, statements of support for policies that address the hazard, or personal behaviors in response to the hazard. This paper focuses on beliefs about radiation and the implications of those beliefs for views about radiation protection by both scientists and members of the U.S. public. We use data from a large sample of scientists, collected in 2002, and a series of surveys of the U.S. public collected in 2007. Among scientists, we focus on how beliefs about radiation are related to policy prescriptions for radiation protection. Among members of the lay public the focus shifts to the relationship between beliefs about radiation risks and policy preferences for nuclear energy and nuclear waste policy options. The importance of the differences and similarities in the patterns of beliefs of scientists and the lay public are discussed.