Research Areas

Human performance is central to the safe and reliable operation of nuclear power plants and other complex systems. In the Probabilistic Safety Assessment (PSA) of human-technical installations, Human Reliability Analysis (HRA) is the part that addresses the human element. In the HRA, the essential personnel actions contributing to and required in potential accident scenarios are identified, qualitatively analyzed, and their probabilities of failures are estimated. A realistic evaluation of the human contribution is key to a sound evaluation of safety and of the potential weaknesses of a facility. This soundness is important to licensee and regulatory decisions that support and enhance safety in all areas, e.g., plant design, operation, maintenance, and accident prevention and mitigation.

The research of LEA's Risk and Human Reliability Group focuses on the following areas.

Human Reliability Analysis Methods

• The enhancement of existing HRA methods and development of methods and tools with the aims to improve HRA qualitative and quantitative predictions and to reduce variability in these results.
• The analysis of Errors of Commission and, more broadly, decision-related failures, the issue of HRA dependence that is closely related to these, and the recovery of decision failures.
• The extension of HRA methods for external hazards PSA and severe accident scenarios.

Dynamic Safety Assessment

The development and application of simulation-based risk assessment methods as a means to better analyze accident scenario dynamics and uncertainties.

One application is to enhance the assessment of safety margins.

Novel Applications of PSA

The application of PSA and the methods of risk and reliability in novel application domains. Our main goal is to bring in the quantitative perspective of PSA and HRA into the safety analyses, to prioritize the risk contributors and identify effectively improve safety. In particular, the group is adapting PSA methods for the risk assessment of PSI's Proton Therapy facilities.