| Abstract Scope |
Water vapor ingress is one of the potential accidents in high-temperature gas-cooled reactors (HTGRs), which can oxidize vulnerable graphite components and compromise the integrity of fuel elements. However, it is impractical to conduct graphite oxidation tests that replicate the large-scale setup of an HTGR core system. In such cases, numerical modeling of graphite oxidation during water ingress accidents serves as an alternative method to predict and assess the global reaction behaviors within the core. The objective of this study is to propose a modeling framework to explore the water vapor oxidation behaviors of a prismatic fuel block, including coolant channels, nuclear graphite, and matrix graphite. The simulation results analyzed the effects of temperatures at the inlet and fuel on the distribution of water vapor within the graphite materials. A transient analysis was also performed to estimate the gasification fraction of graphite at high temperatures. |