Flow Regime Effects on the Neutronic Parameters of Liquid Metal-Gas Two-Phase Flow in a Fusion Reactor Coolant Channel

Abstract

In this work, a heterogeneous Monte Carlo neutron transport code, called HEMCNT, was


used to evaluate the energy deposition, tritium breeding profile and neutron leakage spectrum of


a liquid lithium and inert gas mixture flowing in a fusion reactor coolant channel bombarded by


monoenergetic 14.06 MeV neutrons with and without the present of a transverse magnetic field.


Flow models simulated include: annular, slug, bubbly, and single phase flow. Tube diameter, film


thickness, void fraction and phase redistribution were systematically varied. Numerical results


reveal that the tritium breeding ratio (TBR) and total energy deposited decreases with increasing


void fraction and vice versa for neutron leakage, and, in some case vary nonmonotonically when


undergoing a transition from one flow regime to another. The effect of magnetic fields (up to 00.2


Tesla In this study) does not significantly alters the total tritium production nor the total amount


of heat deposited but may influence the energy deposition profile, neutron streaming, (consequently,


size and cost of the blanket assembly), as well as the temperature gradient (heat transfer) across


the channel.