Computational modeling of hydrogen behavior and thermo-pressure dynamics for safety assessment in nuclear power plants.

This article focuses on the use of advanced computational fluid dynamics (CFD) simulations to analyze hydrogen behavior, pressure dynamics, and the effectiveness of mitigation strategies in nuclear power plant containment structures during severe accident scenarios. It compares small and large containment structures, finding that smaller containments experience rapid hydrogen accumulation and structural failure at lower pressures and shorter times than larger ones, which show delayed pressure buildup and greater resilience. The study highlights that hydrogen concentrations above 35% and temperatures exceeding 1430 °C significantly increase explosion risks and reduce the effectiveness of passive autocatalytic recombiners (PARs), a key mitigation technology. By integrating multiple interacting variables—hydrogen concentration, temperature, and pressure—under dynamic accident conditions, the research provides a more comprehensive assessment of containment integrity and safety system performance, addressing limitations of prior studies that considered these factors in isolation. The findings underscore the need for enhanced safety measures tailored to varying containment sizes and complex accident dynamics to better manage hydrogen risks in nuclear power plants.