Use of Risk Insights in Support of Security and Safeguards Operation and Design

The use of Probabilistic Safety Assessment (PSA) to risk-inform existing nuclear power plant (NPP) licensing bases has been proven effective and offers a means to substantially reduce plant operating costs by accounting for the deterministic conservatisms. For current generation nuclear power plants, the cost of security represents one of the highest recurring operating costs. The need to address multiple adversary constructs and scenarios results in a need to address many low likelihood scenarios with the same rigor as those found to be significant. Further, the target set definition does no consider quantitative factors such as equipment reliability and adversary intent. For future designs, it is possible to optimize security while considering risk-informed attributes in the design and operations. An evolutionary improvement in estimation of security posture would be to consider a true risk perspective that addressed the likelihood of the scenario, the likelihood of target acquisition leading to an adverse condition such as core damage, and the potential for significant offsite consequence. However, at the present time, some of the elements require additional development and a complete integration of the risk informed process may not be easily applied within the regulatory construct. An alternative is to utilize the existing tools and knowledge from the PSA to inform specific topics associated with the assessment of security posture. Insights from the PSA are already being used to help bound target set development for current plants. This paper expands that process to consider a refinement of the target set process to allow for easier protection of key targets that provide the most benefit based on a ranking system using the most important targets and target sets to simplify the final target sets to be protected.