Uncertainty and Sensibility Analysis of Loss-of-Forced-Cooling Accidents for 150-MWt Molten Salt Reactors

摘要: Molten salt reactors (MSRs) are a promising candidate for Generation IV reactor technologies, and the small modular molten salt reactor (SM-MSR), which utilizes low-enriched uranium and thorium fuels, is regarded as a wise development path to accelerate deployment time. Uncertainty and sensitivity analyses of accidents guide nuclear reactor design and safety analyses. Uncertainty analysis can ascertain the safety margin, and sensitivity analysis can reveal the correlation between accident consequences and input parameters. Loss of forced cooling (LOFC) represents an accident scenario of the SM-MSR, and the study of LOFC could offer useful information to improve physical thermohydraulic and structural designs. Therefore, this study investigates the uncertainty of LOFC consequences and the sensitivity of related parameters. The uncertainty of the LOFC consequences was analyzed using the Monte Carlo method, and multiple linear regression was employed to analyze the sensitivity of the input parameters. The uncertainty and sensitivity analyses showed that the maximum reactor outlet fuel salt temperature was 725.5℃, which is lower than the acceptable criterion, and five important parameters influencing LOFC consequences were identified.