Experimental and Numerical Analyses of Hydrogen Flames for the Thermal Testing of Transport Packages for Radioactive Material

Abstract In this paper we present an update of the hydrogen-based test rig for an ongoing feasibility study of using hydrogen as an energy source for the thermal testing of transport packages containing radioactive materials [1]. The test rig is capable of combusting hydrogen for a wide range of different burner geometries, mass flows, hydrogen blends and single jet flame operations as well as a full array of burners for thermal testing can be set up. As this type of fire test according to the IAEA [2] boundary conditions does not yet exist, a large number of preliminary investigations, safety assessments and simulations must be carried out in order to develop a viable concept for hydrogen fires. In a first step of the feasibility study, the temperature, structure, and radiative behavior of hydrogen jet flames must be surveyed. The simulation with a single hydrogen flame was investigated in a previous work [1]. In the next step the results are used to study the interaction and structural behavior of multiple jet flames in proximity with varying nozzle distances. With the test rig completed, it will be possible in future works to design burner frames suitable for fire reference tests to make comparisons with pool and propane fires used in assessment procedure today. Thus, preliminary comparative numerical simulations are conducted to model the behavior of overlapping hydrogen jet flames using the software package Ansys®. This paper gives an overview on the current state and design of the test rig. Furthermore, the results of the simulations show that nozzle geometry, mass flow and nozzle distance provide significant design margin for designing a test fire capable of fully engulfing a specimen.