Evaluating PRA Tools for Accurate and Efficient Quantifications: A FollowUp Benchmarking Study Including FTREX

In the rapidly evolving technological landscape, probabilistic risk assessment (PRA) is increasingly essential in supporting decision-making and engineering processes across multiple industries, particularly in the nuclear sector. Central to the development and safety assurance of nuclear power plants (NPPs), PRA is crucial in navigating the challenges of complex system designs. This study addresses the limitations and current capabilities of traditional PRA tools and emphasizes the necessity for advancements to align with the evolving needs of the industry. We focus on event tree and fault tree analyses methods, widely used in PRA, utilizing tools like SAPHIRE (with SAPHSOLVE engine), Phoenix Architect (CAFTA with PRAQuant and FTREX engines), XFTA engine, and the recent OpenPRA's SCRAM-cpp (previously called SCRAM) open-source engine. Our study extends previous benchmarking to include the industry most utilized FTREX engine. We conduct a detailed evaluation of SAPHSOLVE, FTREX, XFTA, and SCRAM-cpp, using synthetic fault trees of varying specifications and complexities. The analysis aims to assess the accuracy and efficiency of these tools in terms of time and memory use for calculating top event failure probabilities and minimal cut sets. The results will inform enhancements of current PRA tools and contribute to the development of the OpenPRA software platform moving towards improved PRA methodologies in the nuclear industry.