Neutronic and Thermal-Hydraulic Analysis for Small Solid-Liquid Dual-Fuel Reactors With Different Fuel Elements

Abstract Small molten salt reactor (SMSR) is an advanced nuclear energy system with the advantages of high safety and high thermoelectric efficiency. Due to its good development prospect, a new type of cross-shaped spiral fuel has been widely researched around the world. In this paper, the cross-shaped spiral fuel was applied to a small liquid-solid dual-fuel molten salt reactor proposed in our previous study, and the neutronic and thermal-hydraulic performance of the core were investigated respectively by OpenMC and COMSOL and compared with that of the conventional rod-shaped fuel. The results show that using cross-shaped spiralfuel slightly reduces the effective multiplication factor and that the safety performance of small liquid-solid dual-fuel molten salt reactor under accident condition is not significantly different between two fuel elements. The increasing of the rotational angle of the spiral cross-shaped spiral fuel plays an important role in changing the coolant flow and improving the heat transfer performance, the maximum core temperature of cross-shaped spiral fuel is reduced by 16.27% compared with that of the rod-shaped fuel. It can be conclude that adopting cross-spiral fuel can in a small solid-liquid dual-fuel reactors can improve effeciently the heat transfer performance but little affect the neutronics characteristics.