A sub-channel analysis code for advanced lead bismuth fast reactor

Sub-channel analysis is essential to predict the flow, enthalpy and temperature distribution in core center, cladding and coolant outlet. The main international research focuses on the primary loop and there are hardly any special sub-channel analysis program existing. A sub-channel analysis code of steady-state (SACOS-PB) has been developed for the preliminary analysis in advanced lead bismuth fast reactor (ALBFR) fuel in Xi'an Jiao tong University. This paper uses SACOS-PB program to analyze ALBFR sub-channel characters. The results show that the maximum core center and cladding temperature are below the limit of design. What's more, this paper also investigates the optimum pitch to diameter ratio in PBWFR with a new analytical method. After the research, the author finds that the optimum pitch to diameter ratio is 1.27 and the result coincides well with the real ratio in PBWFR, which proves the correctness of our new pitch to diameter ratio analytical method. ► We obtain the optimum pitch to diameter ratio in PBWFR is 1.27. ► The temperature peak of the coolant lies at the outlet of the rod. ► The cladding surface peak temperature stays near the axial central position. ► The highest coolant temperature of lead bismuth eutectic is under control and the highest cladding temperature is less than the limited temperature. ► Then the hexagon assembly is the best assembly structure.