Simulation of Water - Liquid Lead-Bismuth Eutectic Interaction Using Simmer-III Code

Abstract

During recent years heavy liquid metal-cooled (HLM) reactors have experienced increasing interest reflected in several European reactor projects, such as EFIT and ELSY LEADER projects. The reactors with the focus on transmutation of Minor Actinides (MA), such as EFIT project, are usually designed with a two-loop system as the HLM does not react vigorously when coming into contact with water/steam or air. The two-loop layout bears however the risk that after a steam generator tube rupture (SGTR) event water and/or steam can be transported into the core which could lead to a reactivity insertion in case of a fast spectrum reactor. Based on this consideration, a series of numerical experiments was carried out in this paper to investigate the phenomenology and behaviour of thermal and hydraulic interactions between water/vapor and liquid LBE alloy using the code SIMMER-III. The computational domain is a vessel, which was initially filled with molten LBE alloy. A pressurized water jet tube was immersed in the liquid LBE pool and injected vertically into the melt pool. Based on the EFIT steam generator idea, an orifice is arranged at the tube entrance to throttle the water/vapour mass flow in case of the pressurized water tube ruptures. The liquid LBE alloy temperature ranges from 400°C to 500°C, while the pressurized water temperature varies from 135°C to 335°C in an interval of 50°C. This research will focus on the water/steam penetration depth variation into the LBE pool influenced by the water and LBE temperatures.