Neutronic Investigation of Inertial Fusion Energy Blankets for HYLIFE-II and Magnetohydrodynamic Applications

The tritium breeding and energy absorption in an inertial fusion energy (IFE) reactor chamber have been investigated with variable coolant zone thickness using different materials. Examples are given for HYLIFE-II (an IFE reactor design) and for magneto-hydrodynamic (MHD) energy conversion chambers using Flibe (Li₂BeF₄) as coolant. Investigations related to MHD are extended to the use of LiH, lithium, and Lil7-Pb83 eutectic as working fluid. Natural lithium is used in all cases, except in the case of LiPb, for which both natural and enriched options were calculated. To achieve a useful energy density for energy conversion purposes with a sufficient tritium breeding ratio (TBR = 1.1 to 1.2), coolant zone thicknesses must be 25 cm for LiH, 50 to 60 cm for Flibe, and 80 cm for lithium. The use of Lil7-Pb83 with natural lithium and with lithium enriched to 90% ⁶Li requires coolant zone thicknesses of 120 and 60 cm, respectively, to obtain a tritium breeding of TBR = 1.1, which gives an extremely low energy deposition density. This low density and the large coolant mass make LiPb unattractive for MHD and HYLIFE-II applications.