Full Title: Helium-Air Mixing in Simulated Reactor Cavities of High Temperature Gas Reactors
Author(s): Abdullah Abubakar, Mathieu Davis, Zayed Ahmed, Dinesh Kalaga, and Masahiro Kawaji
Publisher(s): ScienceDirect
Publication Date: February 22, 2024
Full Text: Download Resource
Description (excerpt):
The spatial and temporal variations in air and helium concentration and temperature fields in simulated reactor cavities of High Temperature Gas Reactor (HTGR) were investigated experimentally. This accident scenario follows a hypothetical small pipe break in the Reactor Pressure Vessel and discharge of high temperature helium into the surrounding cavity. A scaled multi-compartment experimental facility based on the General Atomics Modular High Temperature Gas Reactor (GA-MHTGR) design was constructed and used in the gas mixing experiments. Oxygen sensors and thermocouple probes were installed in all five cavities to measure the oxygen (or helium) concentrations and gas mixture temperature distributions.
The experimental results indicated the significance of the pipe break location and cavity venting configuration in gas mixing phenomena for the HTGR design. If air ingress occurs following Depressurized Conduction Cooling (DCC) of the reactor core, the oxygen concentration near the pipe break could be different depending on the elevation of the break location and the degree of mixing and stratification of helium and air in the reactor building cavities.