A review on PAR operating characteristics and impact on hydrogen behaviors in containment of PWRs

Abstract

Passive autocatalytic recombiners (PARs), owing to its excellent hydrogen removal capability and passive characteristic, have been widely utilized to prevent the potential hydrogen combustion risk in modern PWRs. The analysis of PAR operational characteristics has initially been conducted based on experimental investigations. Subsequently, it has gained the capability to comprehensively study the PAR operational behavior combing with the thermal–hydraulic characteristic and chemical reaction dynamics with the development in reaction kinetics models and advanced computing methods. It is significant to summarize the PAR development for improving the PAR operational behavior and mitigating the hydrogen combustion risk in the containment of PWRs. This paper summarized the operating principles and structural effects of PAR, the PAR operational behavior in various operating conditions, and the interaction between PARs and containment atmosphere in PWRs. Existing research provide substantial experimental and numerical simulation support for examining PAR operational behavior in the accident conditions. However, it remains necessary to conduct relevant researches to effectively use PAR for enhancing hydrogen risk mitigation capability in PWRs. Anticipated research includes improving PAR hydrogen removal capability, evaluating and enhancing PAR operational behavior in complex environments, and providing deeper insights for PARs impacts on the containment atmosphere in the future.