Yuanzineng kexue jishu (Jul 2023)
Code Development and Verification of LBE-water Interaction under Steam Generator Tube Rupture Accident for LBE-cooled Reactor
Abstract
The LBE-cooled reactor is one of the important choices for sustainable and safe development of nuclear energy systems in the future. The safety issues involved with the steam generator tube rupture (SGTR) accident must be considered in the design and operation of such reactors. The essence of the evolutions during this SGTR accident for LBE-cooled reactors is focused on the interaction behaviors between high temperature liquid metal LBE and pressurized water. For such considerations, relevant researches on the mechanistic experiments and numerical simulations have been carried out at home and abroad. However, with respect to the numerical simulations of SGTR accident in LBE-cooled reactor, the traditional system analysis codes based on the typical two-fluid six-equations model, such as RELAP5, ATHLET, etc., are not appropriate here. And the targeted simulation codes used for SGTR in LBE-cooled reactors are still rare, researches in foreign countries are focused on the multi-phase, multi-components, multi-velocities based computational fluid dynamics (CFD) and neutronics coupled code SIMMER-Ⅲ which is developed to analyze the serious accidents of liquid metal cooled fast reactors, such as LBE-cooled reactors or sodium cooled reactors. While domestically, researches are focused on the multi-phase flow codes including NTC-2D and MC3D. It is absolutely of great significance to conduct further and in-depth studies on the fundamental models and numerical algorithms for thus SGTR accident. So, aiming at the interaction behaviors between LBE and water, which is one of the significant scientific issues involved with the accident evolution characteristics and behaviors of SGTR in LBE-cooled reactors, investigations on the basic theories, constitutive models and numerical algorithm were performed in this paper. A new three-fluid code including LBE, liquid water and vapor mixtures was developed, and its verification work was performed by using the published experimental data abroad including the water injecting into LBE liquid metal pool experiment in a small experimental apparatus by Japan JAEA and water injecting into LBE pool experiment in large experimental LIFUS5 series facilities by Italy ENEA. The results show that the new code developed in this paper agrees reasonably on the whole with the experimental results, but certain deviations still exist at some local details compared with the experimental results. On the whole, the relevant research achievements, including the critical related models, algorithms and code modules are able to simulate the interaction behaviors between LBE and water reasonably. The code developed in this paper is expected to provide certain theoretical and technical support for the accident analyses and safety evaluations of SGTR accident in LBE-cooled reactors. Meanwhile, more in-depth researches on the optimizations of the critical models and algorithms should be carried out in the future work.
