Thermal-hydraulic analysis method for the annular fuel structure of lead-bismuth reactor

Abstract

BackgroundAnnular fuel can significantly increase the power density of the lead-bismuth reactor core, which is of great significance to realize miniaturized design of the reactor and fuel economy improvement.PurposeThis study aims to develop an annular fuel calculation program to obtain key thermal and hydraulic parameters, so as to obtain the optimal arrangement of annular fuel under different objectives.MethodsFirst of all, based on the closed parallel multi-channel model and quantum genetic algorithm, the thermal-hydraulic analysis program of the lead-bismuth fast reactor annular fuel was developed through the decoupling calculation of flow distribution and heat distribution. Secondly, five parameters, i.e., the maximum temperature of the fuel pellet, the maximum temperature of the fuel cladding, the temperature difference between the inner and outer outlets, the pressure drop, and the core power, were taking as the evaluation indicators, and the multi-objective comprehensive evaluation method was used to investigate the optimal layout of the annular fuel assembly. [Result&ConclusionsThe results show that the error between the developed lead-bismuth fast reactor annular fuel thermal-hydraulic analysis program and the similar program developed by Nanyang Technological University in Singapore is within 3%. On the basis of ensuring the calculation accuracy, the decoupling calculation of flow distribution and heat distribution significantly improves the computation efficiency of the program. Results of the annular fuel arrangement show that 18×18 arrangement is a better choice from a safety point of view whilst the 16×16 arrangement is the best choice from the economic point of view. Considering comprehensive safety and economy, the 19×19 arrangement has better safety performance and economy.

Keywords

• lead-bismuth cooled fast reactor
• annular fuel
• multi-objective optimization
• optimal arrangement