Risk analysis is the solution to complex problems, and represents the pinnacle of interdisciplinary research and education. Following the Three Mile Island disaster in 1979, Probabilistic Risk Assessment (PRA) has become a key pillar of the risk-informed nuclear regulatory framework, and is now a requirement for every Nuclear Power Plant (NPP) in the United States. Enhancing the prevention of catastrophic technological accidents and the protection of environment requires advancement in multidisciplinary PRA. It demands the development of a common vocabulary within diverse engineering and social science domains in order to address risks emerging from the interface of social and technical systems.
Worldwide, there are very few engineering faculty with interdisciplinary educational training in both reliability engineering and socio-technical risk modeling. Assistant Prof. Zahra Mohaghegh brings to the University of Illinois this unique interdisciplinary background along with over 10 years of experience in PRA methodologies and applications. She has pioneered the development of Socio-Technical Risk Analysis (SoTeRiA), which is a multi-level theoretical risk framework, and is now the name of Mohaghegh’s research team in NPRE.
The SoTeRiA research team has expanded quickly since January 2013, when Mohaghegh Joined NPRE. The team has been committed to solving complex problems by making scientific contributions, and by building collaborations with multiple departments at UIUC, national laboratories, industry partners, and international institutions. The group currently includes PhD and master’s degree students, undergraduate and international interns, a postdoctoral research associate, and a research scientist, from diverse domains including nuclear engineering, mechanical engineering, industrial engineering, and information science. As an advisor of multidisciplinary graduate projects, Mohaghegh is affiliated with Industrial and Enterprise Systems Engineering (ISE), the Graduate School of Library and Information Science (GSLIS), and the Institute of Informatics, all at Illinois, in addition to her NPRE appointment.
The collaboration of the SoTeRiA team has led to the improvement in socio-technical risk theories and the integration of deterministic and probabilistic techniques. The theoretical contribution of SoTeRiA projects is the incorporation of two types of underlying phenomena into PRA (i.e. physical and social failure mechanisms). This incorporation helps identify and manage root causes of systems failure and reduces unnecessary conservatism in NPP operation and design. The methodological contributions of these research projects relates to the integration of classical PRA techniques with simulation-based methods, leading to the development of an Integrated PRA (I-PRA) that enables the modeling of emergent risk behavior by depicting the dynamic interactions of risk contributing factors within their ranges of variability and uncertainty. These cutting-edge PRA models are quantified with state-of-the-art big data analytics techniques, which expand the classical approach of data extraction and implementation for risk analysis. SoTeRiA’s research is the first application of big data analytics for PRA, and access to the National Center for Supercomputing Applications (NCSA) at Illinois will facilitate the SoTeRiA’s leadership in this area.
Some of the on-going SoTeRiA’s research projects include: Fire PRA in NPPs; Probabilistic physics modeling for location-specific Loss of Coolant Accident (LOCA); Incorporating human error and organizational factors in technical system risk models; Socio-technical risk-informed emergency preparedness, planning and response modeling for severe nuclear power accidents; and Evaluating the monetary value of PRA.
Since January 2013, the SoTeRiA research team has supported a large-scale project, the Risk-Informed Resolution of Nuclear Regulatory Commission’s Generic Safety Issue 191 (GSI-191). The project, sponsored by the South Texas Project Nuclear Operating Company (STPNOC), is conducted in collaboration with the University of Texas at Austin, ABS Consulting, Alion Science and Technology Corp, Texas A&M University, and the University of New Mexico. The main objective of the Risk-Informed GSI-191 project is the quantification of risk associated with fibrous insulation material in the STPNOC containment building using PRA, uncertainty quantification, thermal-hydraulic analysis, and laboratory experiments.
SoTeRiA team members have organized, chaired and presented the results of their research at both the American Nuclear Society Risk Management Embedded Topical Meeting and the International Probabilistic Safety Assessment and Management Conference. Recently, one graduate researcher from the SoTeRiA team, Nick O’Shea, was awarded a three-year fellowship from the Department of Energy to support his risk analysis research.
Mohaghegh has also focused on the development of new risk analysis courses in NPRE, which not only enhances graduate research studies, but also prepares engineers and analysts to enter into the nuclear industry and regulatory agencies with a better understanding and knowledge of uncertainties, and how to prevent the “unexpected.”