Research and Analytical Investigation on the Criticality of Molten Salt Reactors and the Quantity of Graphite Flow Channels

Краткое изложение: The molten salt reactor, one of the six fourth-generation reactors, utilizes liquid nuclear fuel and graphite as a moderator. Graphite also functions as a core component, forming fuel salt channels akin to a honeycomb structure. To ensure effective core design management and nuclear safety supervision, it is imperative to analyze the intricate relationship between the graphite structure of the core, fuel salt channels, and critical mass. This study employs software simulation calculations to analyze the impact of varying graphite flow channel quantities and core sizes on the reactivity of the molten salt reactor, through modeling its core dimensions and graphite flow channels. The findings reveal that the design dimensions of the graphite core correlate closely with the total uranium mass within the reaction zone. Notably, the critical total uranium mass required decreases gradually with an increase in the number of fuel salt channels, ultimately reaching a plateau followed by a slight decrease. Drawing upon the characteristics of the graphite flow channels' influence on reactor reactivity, we summarize the regulatory requirements for graphite components from a legal perspective. Furthermore, we offer recommendations for enhancing manufacturing and installation quality, preventing accidental criticality events, and closely monitoring safety parameters from a regulatory standpoint. The conclusion has been reached that there exists an optimal design value for the number of flow channels in the graphite components of liquid fuel molten salt reactors in terms of reactivity.