Selective electromagnetic induction heating of metal particles in molten salt for tritium extraction: A systematic numerical investigation

Abstract

Molten-salt blankets that possess tritium-absorbing metal particles are promising emerging technical components in nuclear fusion reactors. In this study, we develop a numerical model and carry out a systematic analysis of the electromagnetic induction heating of metal particles (Ti, Pd, Mg, Zr, and V) in the molten salt for the extraction of tritium. We show that the maximum absorption power in the metal particles can be normalized in a form independent of the material combination of nonmagnetic metals and salts, and the peak power density per square of magnetic flux density per field frequency is 5.3 × 10⁶ W m⁻³ T⁻² s. Nevertheless, the steady-state temperature difference between the metal particles and the molten salt, a figure of merit of the selective electromagnetic heating scheme, is found to monotonically increase with the metal particle size, in contrast to the behavior of the absorbed power density, thus encouraging the use of larger metal particles. The attainable temperature difference between the Ti particles and the FLiBe blanket is estimated to be 110 °C for a particle diameter of 1 mm in a 2.45 GHz and 1 mT magnetic field, and it increases proportionally with the diameter, square root of frequency, and square of magnetic flux density around this condition.