基于灰色模糊理论的环形燃料元件热工水力敏感性分析

Background]:Annular fuel has the potential to significantly enhance the power density of Pressurized Water Reactor (PWR) cores. This characteristic holds great significance for the realization of the miniaturization design of reactors and the improvement of their economic efficiency.Previous research in this domain has primarily focused on the arrangement patterns of components and a limited number of geometric dimension combinations. Conversely, there has been relatively less research dedicated to the quantitative analysis of the refined geometric structure dimensions of fuel elements. [Purpose]:Thus, quantifying the impact of various geometric factors on the thermohydraulic performance is of substantial importance.[Methods]:In this study, the single-channel model of annular fuel is adopted as the research subject. Thermohydraulic design calculations are carried out based on the parameters of the PWR annular fuel elements designed by Westinghouse. Geometric factors, including the inner and outer diameters of the inner and outer claddings and the inner and outer diameters of the fuel pellets, are selected. Additionally, four evaluation criteria are established. By applying grey relational analysis and the theory of fuzzy mathematics, the influence of each geometric factor on the thermohydraulic performance is quantified.[Results]:The results indicate that, in the MDNBR of both the inner and outer channels, the sensitivities of various geometric factors are comparable. However, differences exist in the position of the adiabatic surface and the maximum temperature of the fuel pellets. [Conclusions]:This quantitative approach provides a valuable reference for the design and parameter adjustment of annular fuel in PWRs.