熔盐快堆稳态核热耦合程序开发及验证

Development and verification of a coupled code of steady-state neutronics and thermal-hydraulics for molten salt fast reactor

无慢化罐式堆芯结构的熔盐快堆(Molten Salt Fast Reactor,MSFR)中存在中子物理与热工水力的强耦合。应用耦合蒙特卡罗粒子输运程序OpenMC与计算流体力学软件OpenFOAM,建立了一套适用于熔盐快堆的三维稳态核热耦合计算程序。该程序基于python编程语言实现了OpenMC和OpenFOAM二者间的功率、燃料盐温度和密度分布等数据交互,可以获得堆芯内三维功率分布、中子通量密度分布、三维速度场和温度场分布。采用该耦合程序,建立了熔盐快堆的基准模型,研究了中子学区域划分数目和初始条件对keff、燃料盐速度和温度分布的影响。根据研究结果,推荐了一套合理的中子学区域划分方法与数目,表明了耦合程序设定的不同初始条件对keff结果无影响。最后,通过与熔盐快堆基准结果的对比验证了耦合程序的正确性,表明该程序适用于熔盐快堆的稳态核热耦合分析。

[Background]There is a strong coupling between the neutronics and thermal-hydraulics in the nonmoderated can-type core of molten salt fast reactor(MSFR).[Purpose]This work aims to develop and verify coupled code for steady-state neutronics and thermal-hydraulics for the MSFR.[Methods]The coupling code was developed using python programming language to exchange the power distribution,fuel salt temperature and density distributions between OpenMC(Monte Carlo particle transport simulation code)and OpenFOAM(computational fluid dynamics software).Based on the coupling code,a benchmark model of MSFR was established,and the effects of the number of neutonics region division and the different initial conditions on the keff,fuel salt velocity and temperature distributions were studied.Finally,the simulation results were compared with the reference results of MSFR.[Results]The three-dimensional power distribution,neutron flux distribution,fuel salt velocity field and temperature field distributions can be obtained by using this coupled code.The benchmark of MSFR shows that different initial conditions have no effect on keff,and an alternative number and scheme of neutronics region division are recommended.The simulation results keep a good agreement with the reference results of MSFR.[Conclusions]This coupled code can provide reliable results for the steady-state neutronics and thermal-hydraulics coupling of MSFR.