Core Optimization And Primary Shielding Design Of Small Molten Salt Lead-based Reactor Based On Genetic Algorithm

Radiation shielding design is an important part in the nuclear engineering design,which is directly related to the radiation safety of nuclear facilities as well as staff,and greatly affects the overall performance of the system.For the special advanced nuclear facilities like nuclear reactors for ships,spacecrafts,vehicle-mounted reactors,and other ones with limited inner space,in addition to constrain the radiation dose in the specified area to meet the design target value,it also needs to strictly restrict the weight and volume of nuclear facilities,which makes the design process even more complex and time-consuming.Therefore,this is a problem involving multi-dimensional and multi-objective optimization.However,in the existed researches on the optimization of nuclear radiation shielding,on one hand,the advantages of the deterministic method and the Monte Carlo method were not truly combined,and the computational efficiency is very low;On the other hand,with more objectives to be optimized,the traditional intelligent optimization algorithms have problems such as poor convergence and single optimization solution,which cannot meet the optimization design of high-dimensional and multi-objective.This paper adopted the scheme of combining high-dimensional multi-objective genetic algorithm with advanced shielding calculation method for the first time,which can not only complete the shielding calculation and analysis in a reasonable time,but also maintain the diversity of population and high computational efficiency in the shielding optimization calculation.An efficient and reliable multi-objective radiation shielding design optimization method framework is established.Based on this method,a multi-objective optimization design platform for small molten salt lead-based reactor is developed by using Py Qt5.The research object of the paper is a small-scaled vehicle-mounted molten salt lead-based reactor.First,based on the developed multi-objective optimization design platform,the core parameter sensitivity calculation is carried out,and the influence of different parameters on the reactivity is determined.Combined with the high-dimensional multi-objective genetic algorithm,multiple parameters of the geometry of the small lead-based reactor core is optimized and a more compact design is obtained.Secondly,for the optimized core,the radiation source items is determined by core physics calculations based on the developed multi-objective optimization design platform,and the burnup process is further studied.Finally,the high-dimensional multi-objective genetic algorithm is combined with the advanced shielding calculation method,and finally the shielding design of the small-scale vehicle-mounted molten salt lead-based reactor is optimized.The calculation results showed that the method proposed and the platform developed in this paper can automatically adjust and iteratively optimize the design parameters of the structure of the small molten salt lead-based reactor and the material of the radiation shielding system,and therefore the core under the constraints of high-dimensional and multi-objective.An optimized shielding scheme with light weight,small size and low protection cost is obtained.The method in this paper can provide favorable reference value for the development and design of new reactors and the conceptual design of radiation shielding for special nuclear facilities.