The Hanford Advisory Board (HAB) is a broadly representative, deliberative body that provides formal policy advice on Department of Energy (DOE) proposals and decisions at the Hanford nuclear cleanup site near Richland, Washington. Despite considerable skepticism about the effectiveness of citizen advisory boards, we contend that the HAB offers promising institutional innovations. Drawing on our analysis of the HAB's formal advice as well as our interviews with board members and agency officials, we explore the HAB's unique design, outline a normative framework for evaluating participatory institutions, and assess the HAB's effectiveness in rendering the DOE accountable to the local public.Keywords Bureaucracy . Deliberative democracy . Hanford Advisory Board . Participatory democracy . Technology Highly technical policy decisions present daunting challenges for democracy, for two reasons. First, their sheer complexity makes them difficult for even informed citizens to understand; second, these decisions are often entrusted to bureaucracies whose officials are not directly accountable to citizens and whose deliberations are often hidden from public view. In order to render government accountable to the public, citizens must be able to see how policy decisions stand to affect their interests and to understand-broadly speaking-the range of available policy alternatives. When they are unable to do so, for either of the two reasons just cited, they find themselves exposed to the discretionary power of bureaucrats, scientists, or policy experts. One of the major tasks of empirically informed democratic theory is to analyze and evaluate practices and institutions that use public participation to try to render highly technical public decision-making more transparent and accountable to the public, and therefore more legitimate (Fischer 2009;Dietz and Stern 2008;Fung and Wright 2003;Kleinman 2000;Dryzek 2010;Fishkin 2011). This paper investigates one such institution: the Hanford Advisory Board (HAB), a broadly representative, deliberative body that provides formal, policy advice on Department of Energy (DOE) proposals and decisions at the Hanford nuclear cleanup site near Richland, Washington. Critics have expressed considerable skepticism about citizen advisory boards as instruments of democratic accountability; they have criticized their lack of independence, their lack of formal power, and their failure to adequately represent affected groups (Laurian 2007; Arnstein 1969;Vari 1995;Lynn and Kartez 1995;Santos and Chess 2003). We use these concerns to frame our central research questions: Does the HAB provide effective democratic oversight and accountability at the Hanford nuclear cleanup site? If so, what specific features of the HAB enable it to serve these democratic purposes? And, more broadly, what lessons can its successes (and limitations) teach us about rendering technical, bureaucratic decisionmaking more accountable to the public?We argue that the HAB serves important democratic functions at Hanford....