Physics of steam injection into molten lead-bismuth eutectic: Interface evolution and pressure shock

In lead-cooled fast reactors, steam generator tube rupture could lead to the discharge of high-pressure steam/water into lead or lead-bismuth eutectic (LBE) and result in several risks to the reactor's safe operation. Due to the differences in the physical properties of LBE and water and limited research in the steam-LBE jet flow, a compressible multi-phase numerical model was set up and used for the investigation of the submerged steam jet in LBE. The jet phase interface evolution pattern was found to be different under different inlet pressures, and the jet structure could travel to neighboring structures in a short time. Moreover, during the initial jet process, there was an initial pressure shock that might have an impact to nozzle itself and close structures along the jet direction. In addition, the (quasi-)back-attack phenomena were both observed, and a pseudo-nozzle structure was found to be responsible for the different patterns of the two phenomena. Those phenomena also brought pressure shock to the tube end, and the condition with an intermediate inlet pressure caused the fiercest pressure shock. Meanwhile, the wave structure at the phase interface was found to be resulted by strong shear flow.