Heat transfer in the argon space of pool-type sodium-cooled fast reactor: Numerical simulation and experimental validation

Abstract

Liquid sodium serves as the coolant in the pool-type sodium-cooled fast reactor. The primary penetration equipment on the primary side is immersed in a sodium pool. Argon gas is employed as the covering gas above liquid sodium. To determine the temperature distribution of the roof slab of the main vessel for strength analysis, it is necessary to analyze the heat transfer characteristics. Owing to the large volume of the original reactor, it is difficult to establish a full-scale experimental model. Consequently, a scaled-down experiment is required to obtain the temperature distribution of the roof slab and argon space. In addition, the complex heat transfer characteristics within the roof slab and argon space make it difficult to maintain similarities between the experimental and original facilities. Numerical simulations are a useful approach for extrapolating an experiment to the original reactor. In this study, a scaled-down heat transfer experimental facility for an argon space (HEFA) was established based on the similarity principle, and a numerical model was set up according to the HEFA. The validity of the numerical methods was confirmed by comparing the experimental and numerical results for the HEFA. Based on similarity theory, the temperature distribution in the HEFA was extrapolated to that in the original reactor. A numerical model was established based on the original reactor. By comparing the extrapolated temperature distribution and numerical distribution of the original reactor, it was found that they were in good agreement. Therefore, the validity of the extrapolated temperature distribution was confirmed.