An Interdisciplinary Decision Framework for Risk-Based Nuclear Power Plant Emergency Planning and Protective-Action Strategy Selection

Emergency planning is a required component of licensing for nuclear power plants. A rare opportunity to redefine emergency preparedness has been created by the ongoing work at the Nuclear Regulatory Commission to develop the capability to address small modular reactors and other new technologies and to transition to a risk-informed performance-based regulatory structure. This dissertation develops a new framework for emergency preparedness that can address the characteristics of new reactor technologies while also addressing the limitations of current methods. A review of the literature, current regulations, and methods identifies gaps and limitations. Statistically valid methods are defined to enable new analysis of uncertainty and use cases in limited regulatory validated computer codes. A new interdisciplinary framework for emergency planning is developed to reduce the barriers present in current methods, then a risk-based model that integrates protective action and hazard dispersion models is defined. This integrated model considers the risk caused by multiple hazards, including radiological and transportation hazards. The interdisciplinary and integrated structure of the model provides the opportunity for new measures of effectiveness that provide additional insights beyond existing metrics.

The integrated model is used to evaluate emergency response at the Peach Bottom Atomic Power Station as a case study. The key findings of this case study provide insight into effects previously not discussed in nuclear power emergency planning studies. The ability to compare protective actions across multiple metrics allows for risk and consequences-based evaluation and provides more information for decision-makers. When combined dose and non-dose risks are considered, many historically common protective action strategies become inadvisable by creating more combined risk than taking no action. Even small amounts of time between initiating a protective action and the release of radiation can potentially result in a substantial reduction of consequences. The behavior of the population has a large impact on consequences but is not sufficiently captured in prior studies.