We analyze an interdiction problem in which a nuclear-material smuggler can traverse the rail and road ports of entry (POEs) along the Mexican and Canadian borders of the United States. Our objective is to determine the optimal locations of a limited number of transparent and non-transparent assets so as to minimize the smuggler’s total probability of evasion, from origin to destination. We choose origins in Mexico and Canada and give the smuggler a diverse set of destinations to choose from. Our analysis aims to provide a complete prioritization and picture of the threat at Mexican and Canadian POEs, leading to insight into practical locations for transparent and non-transparent assets. / text

We analyze an interdiction problem in which a nuclear-material smuggler can traverse multiple transportation networks, wherein each edge has an indigenous probability of evasion. Our objective is to determine the optimal locations of a limited number of radiation detectors at United States ports of entry across multiple networks (maritime, road and rail) so as to minimize the smuggler's total probability of evasion, from origin to destination. We choose geographically diverse potential origins and give the smuggler freedom to move across and between transportation networks. Further, we consider two different models of smuggler behavior in this context. Our analysis aims to provide a complete prioritization and picture of the threat at all ports of entry, leading to insight into good practical locations for detectors. / text

Thesis (DTech (Electrical Engineering))--Cape Peninsula University of Technology, 2016. / The widespread application of nuclear science and technology has been the subject of much concern as well as nuclear safety issues. And to ensure the safety of public life, property and environment, it is indispensable to improve the emergency system for nuclear accidents and the environmental monitoring system for nuclear radiation, so that the occurrence of nuclear accidents, terrorist incidents and the resulting hazards can be prevented or minimized. Due to the benefits of radiation which were earlier and now recognized in the use of X-rays for medical diagnosis and then later with the discoveries of radiation and radioactivity, there was rush in exploiting the medical benefits which eventually led fairly to the recognition of the risks and induced harm associated with it. Thus, only the most obvious harms resulting from high doses of radiation, such as radiation burns, were initially observed and protection efforts were focused on their prevention, mainly for practitioners rather than patients. Subsequently, it was gradually recognized that there were other, less obvious, harmful radiation effects such as radiation-induced cancer, for which there is certain risk even at low doses of radiation.

The electric utility companies that own and/or operate the nation’s 112 licensed commercial nuclear power reactors are required by federal law to provide emergency information to residents living around those plants in advance of a nuclear plant emergency. This requires the owner/operators to acknowledge certain risks (e.g., radiation, nuclear plant accidents, evacuation, etc.) that face people living near nuclear generating plants. This dissertation critiques the effectiveness of pre-emergency risk communication strategies by nuclear utilities. Specifically, the dissertation demonstrates that certain historic message themes about nuclear power- termed the "nuclear ethic" -have become embedded in the rhetoric of current nuclear risk communication programs and downplay or mask the seriousness of nuclear plant emergencies, thereby contributing to the apparent ineffectiveness of these communication programs. For example, a survey of residents living around four nuclear plants who receive utility risk communication materials found that nearly two-thirds said they would not follow official instructions in a nuclear plant emergency. Such promotional rhetoric and images remain a part of nuclear risk communication programs because agencies which regulate nuclear power delegate their responsibility for pre-emergency risk communication to the utilities operating the plants. Moreover, there is little involvement in pre-emergency nuclear risk communication by state and local governments. This suggests that risk communication serves a latent symbolic role rather than a functional role for both the regulatory agencies and the utilities by making both groups appear to be isomorphic with societal goals of safety and security for a risky technology. The dissertation concludes by suggesting federal regulatory agencies, and specifically the Federal Emergency Management Agency, intensify their vigilance of risk communication planning and take steps to create authentic two-way communication between the nuclear utilities and the public living near the plants. One way this could be done is by establishing local citizens advisory committees to assess utility risk communication programs and suggest improvements that would help bridge the gap between the nuclear industry’s view of nuclear plant risk and that of the public. / Ph. D.