B111 Development of Multi-Physics Numerical Simulation System for Sodium-water Reaction Phenomena in Steam Generator of Sodium-cooled Fast Reactors

When a heat transfer tube is failed in a steam generator (SG) of a sodium-cooled fast reactor (SFR), pressurized water and/or water vapor leaks into liquid sodium surrounding the tube and forms a reacting jet with high temperature and high alkali. This reacting jet might cause the secondary failure of adjacent heat transfer tubes due to wastage or over-heating tube rapture resulting in undesirable failure propagation. Therefore, the sodium-water reaction phenomenon (SWR) is one of the most important issues for the design and safety assessment of SFRs. The authors have carried out systematic experiments for the elucidation of SWR and developed a new multi-physics numerical simulation system which is based on mechanistic and theoretical modeling of SWR rather than empirical modeling and can contribute to detailed and quantitative evaluations of SWR in any types of SGs. This paper summarizes the results of four years' R&D activities.