Natural circulation characteristics under various conditions on heavy liquid metal test loop

Abstract

In advanced small modular reactors, a natural circulation system with liquid metal is preferred, as it offers enhanced safety features, simplicity of reactor design, and is economical with respect to construction. A natural circulation system also provides potential non-proliferation benefits to the international community. To test lead-bismuth eutectic as a liquid metal coolant, we have studied its natural circulation characteristics. We present the results of experiments on natural circulation conducted in a full-height scale test loop for varying core power, heat exchanger coolant oil temperature, and bubble injection rate. The experiments on the liquid metal were conducted under core power source conditions ranging from 2.5 kW to 15 kW. The aim of this experiment was to study natural circulation under various conditions. With our demonstration facility-based technology, we plan to verify small modular reactor cooling system safety and the technology of the bubble injection system that has been developed for liquid metal flow devices.